| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ A T T R -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2018, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 3, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
| -- http://www.gnu.org/licenses for a complete copy of the license. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with Ada.Characters.Latin_1; use Ada.Characters.Latin_1; |
| |
| with Atree; use Atree; |
| with Casing; use Casing; |
| with Checks; use Checks; |
| with Debug; use Debug; |
| with Einfo; use Einfo; |
| with Elists; use Elists; |
| with Errout; use Errout; |
| with Eval_Fat; |
| with Exp_Dist; use Exp_Dist; |
| with Exp_Util; use Exp_Util; |
| with Expander; use Expander; |
| with Freeze; use Freeze; |
| with Gnatvsn; use Gnatvsn; |
| with Itypes; use Itypes; |
| with Lib; use Lib; |
| with Lib.Xref; use Lib.Xref; |
| with Nlists; use Nlists; |
| with Nmake; use Nmake; |
| with Opt; use Opt; |
| with Restrict; use Restrict; |
| with Rident; use Rident; |
| with Rtsfind; use Rtsfind; |
| with Sdefault; |
| with Sem; use Sem; |
| with Sem_Aux; use Sem_Aux; |
| with Sem_Cat; use Sem_Cat; |
| with Sem_Ch6; use Sem_Ch6; |
| with Sem_Ch8; use Sem_Ch8; |
| with Sem_Ch10; use Sem_Ch10; |
| with Sem_Dim; use Sem_Dim; |
| with Sem_Dist; use Sem_Dist; |
| with Sem_Elab; use Sem_Elab; |
| with Sem_Elim; use Sem_Elim; |
| with Sem_Eval; use Sem_Eval; |
| with Sem_Prag; use Sem_Prag; |
| with Sem_Res; use Sem_Res; |
| with Sem_Type; use Sem_Type; |
| with Sem_Util; use Sem_Util; |
| with Sem_Warn; |
| with Stand; use Stand; |
| with Sinfo; use Sinfo; |
| with Sinput; use Sinput; |
| with System; |
| with Stringt; use Stringt; |
| with Style; |
| with Stylesw; use Stylesw; |
| with Targparm; use Targparm; |
| with Ttypes; use Ttypes; |
| with Tbuild; use Tbuild; |
| with Uintp; use Uintp; |
| with Uname; use Uname; |
| with Urealp; use Urealp; |
| |
| with System.CRC32; use System.CRC32; |
| |
| package body Sem_Attr is |
| |
| True_Value : constant Uint := Uint_1; |
| False_Value : constant Uint := Uint_0; |
| -- Synonyms to be used when these constants are used as Boolean values |
| |
| Bad_Attribute : exception; |
| -- Exception raised if an error is detected during attribute processing, |
| -- used so that we can abandon the processing so we don't run into |
| -- trouble with cascaded errors. |
| |
| -- The following array is the list of attributes defined in the Ada 83 RM. |
| -- In Ada 83 mode, these are the only recognized attributes. In other Ada |
| -- modes all these attributes are recognized, even if removed in Ada 95. |
| |
| Attribute_83 : constant Attribute_Class_Array := Attribute_Class_Array'( |
| Attribute_Address | |
| Attribute_Aft | |
| Attribute_Alignment | |
| Attribute_Base | |
| Attribute_Callable | |
| Attribute_Constrained | |
| Attribute_Count | |
| Attribute_Delta | |
| Attribute_Digits | |
| Attribute_Emax | |
| Attribute_Epsilon | |
| Attribute_First | |
| Attribute_First_Bit | |
| Attribute_Fore | |
| Attribute_Image | |
| Attribute_Large | |
| Attribute_Last | |
| Attribute_Last_Bit | |
| Attribute_Leading_Part | |
| Attribute_Length | |
| Attribute_Machine_Emax | |
| Attribute_Machine_Emin | |
| Attribute_Machine_Mantissa | |
| Attribute_Machine_Overflows | |
| Attribute_Machine_Radix | |
| Attribute_Machine_Rounds | |
| Attribute_Mantissa | |
| Attribute_Pos | |
| Attribute_Position | |
| Attribute_Pred | |
| Attribute_Range | |
| Attribute_Safe_Emax | |
| Attribute_Safe_Large | |
| Attribute_Safe_Small | |
| Attribute_Size | |
| Attribute_Small | |
| Attribute_Storage_Size | |
| Attribute_Succ | |
| Attribute_Terminated | |
| Attribute_Val | |
| Attribute_Value | |
| Attribute_Width => True, |
| others => False); |
| |
| -- The following array is the list of attributes defined in the Ada 2005 |
| -- RM which are not defined in Ada 95. These are recognized in Ada 95 mode, |
| -- but in Ada 95 they are considered to be implementation defined. |
| |
| Attribute_05 : constant Attribute_Class_Array := Attribute_Class_Array'( |
| Attribute_Machine_Rounding | |
| Attribute_Mod | |
| Attribute_Priority | |
| Attribute_Stream_Size | |
| Attribute_Wide_Wide_Width => True, |
| others => False); |
| |
| -- The following array is the list of attributes defined in the Ada 2012 |
| -- RM which are not defined in Ada 2005. These are recognized in Ada 95 |
| -- and Ada 2005 modes, but are considered to be implementation defined. |
| |
| Attribute_12 : constant Attribute_Class_Array := Attribute_Class_Array'( |
| Attribute_First_Valid | |
| Attribute_Has_Same_Storage | |
| Attribute_Last_Valid | |
| Attribute_Max_Alignment_For_Allocation => True, |
| others => False); |
| |
| -- The following array contains all attributes that imply a modification |
| -- of their prefixes or result in an access value. Such prefixes can be |
| -- considered as lvalues. |
| |
| Attribute_Name_Implies_Lvalue_Prefix : constant Attribute_Class_Array := |
| Attribute_Class_Array'( |
| Attribute_Access | |
| Attribute_Address | |
| Attribute_Input | |
| Attribute_Read | |
| Attribute_Unchecked_Access | |
| Attribute_Unrestricted_Access => True, |
| others => False); |
| |
| ----------------------- |
| -- Local_Subprograms -- |
| ----------------------- |
| |
| procedure Eval_Attribute (N : Node_Id); |
| -- Performs compile time evaluation of attributes where possible, leaving |
| -- the Is_Static_Expression/Raises_Constraint_Error flags appropriately |
| -- set, and replacing the node with a literal node if the value can be |
| -- computed at compile time. All static attribute references are folded, |
| -- as well as a number of cases of non-static attributes that can always |
| -- be computed at compile time (e.g. floating-point model attributes that |
| -- are applied to non-static subtypes). Of course in such cases, the |
| -- Is_Static_Expression flag will not be set on the resulting literal. |
| -- Note that the only required action of this procedure is to catch the |
| -- static expression cases as described in the RM. Folding of other cases |
| -- is done where convenient, but some additional non-static folding is in |
| -- Expand_N_Attribute_Reference in cases where this is more convenient. |
| |
| function Is_Anonymous_Tagged_Base |
| (Anon : Entity_Id; |
| Typ : Entity_Id) return Boolean; |
| -- For derived tagged types that constrain parent discriminants we build |
| -- an anonymous unconstrained base type. We need to recognize the relation |
| -- between the two when analyzing an access attribute for a constrained |
| -- component, before the full declaration for Typ has been analyzed, and |
| -- where therefore the prefix of the attribute does not match the enclosing |
| -- scope. |
| |
| procedure Set_Boolean_Result (N : Node_Id; B : Boolean); |
| -- Rewrites node N with an occurrence of either Standard_False or |
| -- Standard_True, depending on the value of the parameter B. The |
| -- result is marked as a static expression. |
| |
| function Statically_Denotes_Object (N : Node_Id) return Boolean; |
| -- Predicate used to check the legality of the prefix to 'Loop_Entry and |
| -- 'Old, when the prefix is not an entity name. Current RM specfies that |
| -- the prefix must be a direct or expanded name, but it has been proposed |
| -- that the prefix be allowed to be a selected component that does not |
| -- depend on a discriminant, or an indexed component with static indices. |
| -- Current code for this predicate implements this more permissive |
| -- implementation. |
| |
| ----------------------- |
| -- Analyze_Attribute -- |
| ----------------------- |
| |
| procedure Analyze_Attribute (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Aname : constant Name_Id := Attribute_Name (N); |
| P : constant Node_Id := Prefix (N); |
| Exprs : constant List_Id := Expressions (N); |
| Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname); |
| E1 : Node_Id; |
| E2 : Node_Id; |
| |
| P_Type : Entity_Id := Empty; |
| -- Type of prefix after analysis |
| |
| P_Base_Type : Entity_Id := Empty; |
| -- Base type of prefix after analysis |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| procedure Address_Checks; |
| -- Semantic checks for valid use of Address attribute. This was made |
| -- a separate routine with the idea of using it for unrestricted access |
| -- which seems like it should follow the same rules, but that turned |
| -- out to be impractical. So now this is only used for Address. |
| |
| procedure Analyze_Access_Attribute; |
| -- Used for Access, Unchecked_Access, Unrestricted_Access attributes. |
| -- Internally, Id distinguishes which of the three cases is involved. |
| |
| procedure Analyze_Attribute_Old_Result |
| (Legal : out Boolean; |
| Spec_Id : out Entity_Id); |
| -- Common processing for attributes 'Old and 'Result. The routine checks |
| -- that the attribute appears in a postcondition-like aspect or pragma |
| -- associated with a suitable subprogram or a body. Flag Legal is set |
| -- when the above criteria are met. Spec_Id denotes the entity of the |
| -- subprogram [body] or Empty if the attribute is illegal. |
| |
| procedure Analyze_Image_Attribute (Str_Typ : Entity_Id); |
| -- Common processing for attributes 'Img, 'Image, 'Wide_Image, and |
| -- 'Wide_Wide_Image. The routine checks that the prefix is valid and |
| -- sets the type of the attribute to the one specified by Str_Typ (e.g. |
| -- Standard_String for 'Image and Standard_Wide_String for 'Wide_Image). |
| |
| procedure Bad_Attribute_For_Predicate; |
| -- Output error message for use of a predicate (First, Last, Range) not |
| -- allowed with a type that has predicates. If the type is a generic |
| -- actual, then the message is a warning, and we generate code to raise |
| -- program error with an appropriate reason. No error message is given |
| -- for internally generated uses of the attributes. This legality rule |
| -- only applies to scalar types. |
| |
| procedure Check_Array_Or_Scalar_Type; |
| -- Common procedure used by First, Last, Range attribute to check |
| -- that the prefix is a constrained array or scalar type, or a name |
| -- of an array object, and that an argument appears only if appropriate |
| -- (i.e. only in the array case). |
| |
| procedure Check_Array_Type; |
| -- Common semantic checks for all array attributes. Checks that the |
| -- prefix is a constrained array type or the name of an array object. |
| -- The error message for non-arrays is specialized appropriately. |
| |
| procedure Check_Asm_Attribute; |
| -- Common semantic checks for Asm_Input and Asm_Output attributes |
| |
| procedure Check_Component; |
| -- Common processing for Bit_Position, First_Bit, Last_Bit, and |
| -- Position. Checks prefix is an appropriate selected component. |
| |
| procedure Check_Decimal_Fixed_Point_Type; |
| -- Check that prefix of attribute N is a decimal fixed-point type |
| |
| procedure Check_Dereference; |
| -- If the prefix of attribute is an object of an access type, then |
| -- introduce an explicit dereference, and adjust P_Type accordingly. |
| |
| procedure Check_Discrete_Type; |
| -- Verify that prefix of attribute N is a discrete type |
| |
| procedure Check_E0; |
| -- Check that no attribute arguments are present |
| |
| procedure Check_Either_E0_Or_E1; |
| -- Check that there are zero or one attribute arguments present |
| |
| procedure Check_E1; |
| -- Check that exactly one attribute argument is present |
| |
| procedure Check_E2; |
| -- Check that two attribute arguments are present |
| |
| procedure Check_Enum_Image; |
| -- If the prefix type of 'Image is an enumeration type, set all its |
| -- literals as referenced, since the image function could possibly end |
| -- up referencing any of the literals indirectly. Same for Enum_Val. |
| -- Set the flag only if the reference is in the main code unit. Same |
| -- restriction when resolving 'Value; otherwise an improperly set |
| -- reference when analyzing an inlined body will lose a proper |
| -- warning on a useless with_clause. |
| |
| procedure Check_First_Last_Valid; |
| -- Perform all checks for First_Valid and Last_Valid attributes |
| |
| procedure Check_Fixed_Point_Type; |
| -- Verify that prefix of attribute N is a fixed type |
| |
| procedure Check_Fixed_Point_Type_0; |
| -- Verify that prefix of attribute N is a fixed type and that |
| -- no attribute expressions are present. |
| |
| procedure Check_Floating_Point_Type; |
| -- Verify that prefix of attribute N is a float type |
| |
| procedure Check_Floating_Point_Type_0; |
| -- Verify that prefix of attribute N is a float type and that |
| -- no attribute expressions are present. |
| |
| procedure Check_Floating_Point_Type_1; |
| -- Verify that prefix of attribute N is a float type and that |
| -- exactly one attribute expression is present. |
| |
| procedure Check_Floating_Point_Type_2; |
| -- Verify that prefix of attribute N is a float type and that |
| -- two attribute expressions are present |
| |
| procedure Check_SPARK_05_Restriction_On_Attribute; |
| -- Issue an error in formal mode because attribute N is allowed |
| |
| procedure Check_Integer_Type; |
| -- Verify that prefix of attribute N is an integer type |
| |
| procedure Check_Modular_Integer_Type; |
| -- Verify that prefix of attribute N is a modular integer type |
| |
| procedure Check_Not_CPP_Type; |
| -- Check that P (the prefix of the attribute) is not an CPP type |
| -- for which no Ada predefined primitive is available. |
| |
| procedure Check_Not_Incomplete_Type; |
| -- Check that P (the prefix of the attribute) is not an incomplete |
| -- type or a private type for which no full view has been given. |
| |
| procedure Check_Object_Reference (P : Node_Id); |
| -- Check that P is an object reference |
| |
| procedure Check_PolyORB_Attribute; |
| -- Validity checking for PolyORB/DSA attribute |
| |
| procedure Check_Program_Unit; |
| -- Verify that prefix of attribute N is a program unit |
| |
| procedure Check_Real_Type; |
| -- Verify that prefix of attribute N is fixed or float type |
| |
| procedure Check_Scalar_Type; |
| -- Verify that prefix of attribute N is a scalar type |
| |
| procedure Check_Standard_Prefix; |
| -- Verify that prefix of attribute N is package Standard. Also checks |
| -- that there are no arguments. |
| |
| procedure Check_Stream_Attribute (Nam : TSS_Name_Type); |
| -- Validity checking for stream attribute. Nam is the TSS name of the |
| -- corresponding possible defined attribute function (e.g. for the |
| -- Read attribute, Nam will be TSS_Stream_Read). |
| |
| procedure Check_System_Prefix; |
| -- Verify that prefix of attribute N is package System |
| |
| procedure Check_Task_Prefix; |
| -- Verify that prefix of attribute N is a task or task type |
| |
| procedure Check_Type; |
| -- Verify that the prefix of attribute N is a type |
| |
| procedure Check_Unit_Name (Nod : Node_Id); |
| -- Check that Nod is of the form of a library unit name, i.e that |
| -- it is an identifier, or a selected component whose prefix is |
| -- itself of the form of a library unit name. Note that this is |
| -- quite different from Check_Program_Unit, since it only checks |
| -- the syntactic form of the name, not the semantic identity. This |
| -- is because it is used with attributes (Elab_Body, Elab_Spec and |
| -- Elaborated) which can refer to non-visible unit. |
| |
| procedure Error_Attr (Msg : String; Error_Node : Node_Id); |
| pragma No_Return (Error_Attr); |
| procedure Error_Attr; |
| pragma No_Return (Error_Attr); |
| -- Posts error using Error_Msg_N at given node, sets type of attribute |
| -- node to Any_Type, and then raises Bad_Attribute to avoid any further |
| -- semantic processing. The message typically contains a % insertion |
| -- character which is replaced by the attribute name. The call with |
| -- no arguments is used when the caller has already generated the |
| -- required error messages. |
| |
| procedure Error_Attr_P (Msg : String); |
| pragma No_Return (Error_Attr_P); |
| -- Like Error_Attr, but error is posted at the start of the prefix |
| |
| procedure Legal_Formal_Attribute; |
| -- Common processing for attributes Definite and Has_Discriminants. |
| -- Checks that prefix is generic indefinite formal type. |
| |
| procedure Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements; |
| -- Common processing for attributes Max_Alignment_For_Allocation and |
| -- Max_Size_In_Storage_Elements. |
| |
| procedure Min_Max; |
| -- Common processing for attributes Max and Min |
| |
| procedure Standard_Attribute (Val : Int); |
| -- Used to process attributes whose prefix is package Standard which |
| -- yield values of type Universal_Integer. The attribute reference |
| -- node is rewritten with an integer literal of the given value which |
| -- is marked as static. |
| |
| procedure Uneval_Old_Msg; |
| -- Called when Loop_Entry or Old is used in a potentially unevaluated |
| -- expression. Generates appropriate message or warning depending on |
| -- the setting of Opt.Uneval_Old (or flags in an N_Aspect_Specification |
| -- node in the aspect case). |
| |
| procedure Unexpected_Argument (En : Node_Id); |
| pragma No_Return (Unexpected_Argument); |
| -- Signal unexpected attribute argument (En is the argument), and then |
| -- raises Bad_Attribute to avoid any further semantic processing. |
| |
| procedure Validate_Non_Static_Attribute_Function_Call; |
| -- Called when processing an attribute that is a function call to a |
| -- non-static function, i.e. an attribute function that either takes |
| -- non-scalar arguments or returns a non-scalar result. Verifies that |
| -- such a call does not appear in a preelaborable context. |
| |
| -------------------- |
| -- Address_Checks -- |
| -------------------- |
| |
| procedure Address_Checks is |
| begin |
| -- An Address attribute created by expansion is legal even when it |
| -- applies to other entity-denoting expressions. |
| |
| if not Comes_From_Source (N) then |
| return; |
| |
| -- Address attribute on a protected object self reference is legal |
| |
| elsif Is_Protected_Self_Reference (P) then |
| return; |
| |
| -- Address applied to an entity |
| |
| elsif Is_Entity_Name (P) then |
| declare |
| Ent : constant Entity_Id := Entity (P); |
| |
| begin |
| if Is_Subprogram (Ent) then |
| Set_Address_Taken (Ent); |
| Kill_Current_Values (Ent); |
| |
| -- An Address attribute is accepted when generated by the |
| -- compiler for dispatching operation, and an error is |
| -- issued once the subprogram is frozen (to avoid confusing |
| -- errors about implicit uses of Address in the dispatch |
| -- table initialization). |
| |
| if Has_Pragma_Inline_Always (Entity (P)) |
| and then Comes_From_Source (P) |
| then |
| Error_Attr_P |
| ("prefix of % attribute cannot be Inline_Always " |
| & "subprogram"); |
| |
| -- It is illegal to apply 'Address to an intrinsic |
| -- subprogram. This is now formalized in AI05-0095. |
| -- In an instance, an attempt to obtain 'Address of an |
| -- intrinsic subprogram (e.g the renaming of a predefined |
| -- operator that is an actual) raises Program_Error. |
| |
| elsif Convention (Ent) = Convention_Intrinsic then |
| if In_Instance then |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Address_Of_Intrinsic)); |
| |
| else |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N |
| ("cannot take % of intrinsic subprogram", N); |
| end if; |
| |
| -- Issue an error if prefix denotes an eliminated subprogram |
| |
| else |
| Check_For_Eliminated_Subprogram (P, Ent); |
| end if; |
| |
| -- Object or label reference |
| |
| elsif Is_Object (Ent) or else Ekind (Ent) = E_Label then |
| Set_Address_Taken (Ent); |
| |
| -- Deal with No_Implicit_Aliasing restriction |
| |
| if Restriction_Check_Required (No_Implicit_Aliasing) then |
| if not Is_Aliased_View (P) then |
| Check_Restriction (No_Implicit_Aliasing, P); |
| else |
| Check_No_Implicit_Aliasing (P); |
| end if; |
| end if; |
| |
| -- If we have an address of an object, and the attribute |
| -- comes from source, then set the object as potentially |
| -- source modified. We do this because the resulting address |
| -- can potentially be used to modify the variable and we |
| -- might not detect this, leading to some junk warnings. |
| |
| Set_Never_Set_In_Source (Ent, False); |
| |
| -- Allow Address to be applied to task or protected type, |
| -- returning null address (what is that about???) |
| |
| elsif (Is_Concurrent_Type (Etype (Ent)) |
| and then Etype (Ent) = Base_Type (Ent)) |
| or else Ekind (Ent) = E_Package |
| or else Is_Generic_Unit (Ent) |
| then |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N))); |
| |
| -- Anything else is illegal |
| |
| else |
| Error_Attr ("invalid prefix for % attribute", P); |
| end if; |
| end; |
| |
| -- Object is OK |
| |
| elsif Is_Object_Reference (P) then |
| return; |
| |
| -- Subprogram called using dot notation |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Is_Subprogram (Entity (Selector_Name (P))) |
| then |
| return; |
| |
| -- What exactly are we allowing here ??? and is this properly |
| -- documented in the sinfo documentation for this node ??? |
| |
| elsif Relaxed_RM_Semantics |
| and then Nkind (P) = N_Attribute_Reference |
| then |
| return; |
| |
| -- All other non-entity name cases are illegal |
| |
| else |
| Error_Attr ("invalid prefix for % attribute", P); |
| end if; |
| end Address_Checks; |
| |
| ------------------------------ |
| -- Analyze_Access_Attribute -- |
| ------------------------------ |
| |
| procedure Analyze_Access_Attribute is |
| Acc_Type : Entity_Id; |
| |
| Scop : Entity_Id; |
| Typ : Entity_Id; |
| |
| function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id; |
| -- Build an access-to-object type whose designated type is DT, |
| -- and whose Ekind is appropriate to the attribute type. The |
| -- type that is constructed is returned as the result. |
| |
| procedure Build_Access_Subprogram_Type (P : Node_Id); |
| -- Build an access to subprogram whose designated type is the type of |
| -- the prefix. If prefix is overloaded, so is the node itself. The |
| -- result is stored in Acc_Type. |
| |
| function OK_Self_Reference return Boolean; |
| -- An access reference whose prefix is a type can legally appear |
| -- within an aggregate, where it is obtained by expansion of |
| -- a defaulted aggregate. The enclosing aggregate that contains |
| -- the self-referenced is flagged so that the self-reference can |
| -- be expanded into a reference to the target object (see exp_aggr). |
| |
| ------------------------------ |
| -- Build_Access_Object_Type -- |
| ------------------------------ |
| |
| function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is |
| Typ : constant Entity_Id := |
| New_Internal_Entity |
| (E_Access_Attribute_Type, Current_Scope, Loc, 'A'); |
| begin |
| Set_Etype (Typ, Typ); |
| Set_Is_Itype (Typ); |
| Set_Associated_Node_For_Itype (Typ, N); |
| Set_Directly_Designated_Type (Typ, DT); |
| return Typ; |
| end Build_Access_Object_Type; |
| |
| ---------------------------------- |
| -- Build_Access_Subprogram_Type -- |
| ---------------------------------- |
| |
| procedure Build_Access_Subprogram_Type (P : Node_Id) is |
| Index : Interp_Index; |
| It : Interp; |
| |
| procedure Check_Local_Access (E : Entity_Id); |
| -- Deal with possible access to local subprogram. If we have such |
| -- an access, we set a flag to kill all tracked values on any call |
| -- because this access value may be passed around, and any called |
| -- code might use it to access a local procedure which clobbers a |
| -- tracked value. If the scope is a loop or block, indicate that |
| -- value tracking is disabled for the enclosing subprogram. |
| |
| function Get_Kind (E : Entity_Id) return Entity_Kind; |
| -- Distinguish between access to regular/protected subprograms |
| |
| ------------------------ |
| -- Check_Local_Access -- |
| ------------------------ |
| |
| procedure Check_Local_Access (E : Entity_Id) is |
| begin |
| if not Is_Library_Level_Entity (E) then |
| Set_Suppress_Value_Tracking_On_Call (Current_Scope); |
| Set_Suppress_Value_Tracking_On_Call |
| (Nearest_Dynamic_Scope (Current_Scope)); |
| end if; |
| end Check_Local_Access; |
| |
| -------------- |
| -- Get_Kind -- |
| -------------- |
| |
| function Get_Kind (E : Entity_Id) return Entity_Kind is |
| begin |
| if Convention (E) = Convention_Protected then |
| return E_Access_Protected_Subprogram_Type; |
| else |
| return E_Access_Subprogram_Type; |
| end if; |
| end Get_Kind; |
| |
| -- Start of processing for Build_Access_Subprogram_Type |
| |
| begin |
| -- In the case of an access to subprogram, use the name of the |
| -- subprogram itself as the designated type. Type-checking in |
| -- this case compares the signatures of the designated types. |
| |
| -- Note: This fragment of the tree is temporarily malformed |
| -- because the correct tree requires an E_Subprogram_Type entity |
| -- as the designated type. In most cases this designated type is |
| -- later overridden by the semantics with the type imposed by the |
| -- context during the resolution phase. In the specific case of |
| -- the expression Address!(Prim'Unrestricted_Access), used to |
| -- initialize slots of dispatch tables, this work will be done by |
| -- the expander (see Exp_Aggr). |
| |
| -- The reason to temporarily add this kind of node to the tree |
| -- instead of a proper E_Subprogram_Type itype, is the following: |
| -- in case of errors found in the source file we report better |
| -- error messages. For example, instead of generating the |
| -- following error: |
| |
| -- "expected access to subprogram with profile |
| -- defined at line X" |
| |
| -- we currently generate: |
| |
| -- "expected access to function Z defined at line X" |
| |
| Set_Etype (N, Any_Type); |
| |
| if not Is_Overloaded (P) then |
| Check_Local_Access (Entity (P)); |
| |
| if not Is_Intrinsic_Subprogram (Entity (P)) then |
| Acc_Type := Create_Itype (Get_Kind (Entity (P)), N); |
| Set_Is_Public (Acc_Type, False); |
| Set_Etype (Acc_Type, Acc_Type); |
| Set_Convention (Acc_Type, Convention (Entity (P))); |
| Set_Directly_Designated_Type (Acc_Type, Entity (P)); |
| Set_Etype (N, Acc_Type); |
| Freeze_Before (N, Acc_Type); |
| end if; |
| |
| else |
| Get_First_Interp (P, Index, It); |
| while Present (It.Nam) loop |
| Check_Local_Access (It.Nam); |
| |
| if not Is_Intrinsic_Subprogram (It.Nam) then |
| Acc_Type := Create_Itype (Get_Kind (It.Nam), N); |
| Set_Is_Public (Acc_Type, False); |
| Set_Etype (Acc_Type, Acc_Type); |
| Set_Convention (Acc_Type, Convention (It.Nam)); |
| Set_Directly_Designated_Type (Acc_Type, It.Nam); |
| Add_One_Interp (N, Acc_Type, Acc_Type); |
| Freeze_Before (N, Acc_Type); |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end if; |
| |
| -- Cannot be applied to intrinsic. Looking at the tests above, |
| -- the only way Etype (N) can still be set to Any_Type is if |
| -- Is_Intrinsic_Subprogram was True for some referenced entity. |
| |
| if Etype (N) = Any_Type then |
| Error_Attr_P ("prefix of % attribute cannot be intrinsic"); |
| end if; |
| end Build_Access_Subprogram_Type; |
| |
| ---------------------- |
| -- OK_Self_Reference -- |
| ---------------------- |
| |
| function OK_Self_Reference return Boolean is |
| Par : Node_Id; |
| |
| begin |
| Par := Parent (N); |
| while Present (Par) |
| and then |
| (Nkind (Par) = N_Component_Association |
| or else Nkind (Par) in N_Subexpr) |
| loop |
| if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then |
| if Etype (Par) = Typ then |
| Set_Has_Self_Reference (Par); |
| |
| -- Check the context: the aggregate must be part of the |
| -- initialization of a type or component, or it is the |
| -- resulting expansion in an initialization procedure. |
| |
| if Is_Init_Proc (Current_Scope) then |
| return True; |
| else |
| Par := Parent (Par); |
| while Present (Par) loop |
| if Nkind (Par) = N_Full_Type_Declaration then |
| return True; |
| end if; |
| |
| Par := Parent (Par); |
| end loop; |
| end if; |
| |
| return False; |
| end if; |
| end if; |
| |
| Par := Parent (Par); |
| end loop; |
| |
| -- No enclosing aggregate, or not a self-reference |
| |
| return False; |
| end OK_Self_Reference; |
| |
| -- Start of processing for Analyze_Access_Attribute |
| |
| begin |
| Check_SPARK_05_Restriction_On_Attribute; |
| Check_E0; |
| |
| if Nkind (P) = N_Character_Literal then |
| Error_Attr_P |
| ("prefix of % attribute cannot be enumeration literal"); |
| end if; |
| |
| -- Preserve relevant elaboration-related attributes of the context |
| -- which are no longer available or very expensive to recompute once |
| -- analysis, resolution, and expansion are over. |
| |
| Mark_Elaboration_Attributes |
| (N_Id => N, |
| Checks => True, |
| Modes => True, |
| Warnings => True); |
| |
| -- Save the scenario for later examination by the ABE Processing |
| -- phase. |
| |
| Record_Elaboration_Scenario (N); |
| |
| -- Case of access to subprogram |
| |
| if Is_Entity_Name (P) and then Is_Overloadable (Entity (P)) then |
| if Has_Pragma_Inline_Always (Entity (P)) then |
| Error_Attr_P |
| ("prefix of % attribute cannot be Inline_Always subprogram"); |
| |
| elsif Aname = Name_Unchecked_Access then |
| Error_Attr ("attribute% cannot be applied to a subprogram", P); |
| end if; |
| |
| -- Issue an error if the prefix denotes an eliminated subprogram |
| |
| Check_For_Eliminated_Subprogram (P, Entity (P)); |
| |
| -- Check for obsolescent subprogram reference |
| |
| Check_Obsolescent_2005_Entity (Entity (P), P); |
| |
| -- Build the appropriate subprogram type |
| |
| Build_Access_Subprogram_Type (P); |
| |
| -- For P'Access or P'Unrestricted_Access, where P is a nested |
| -- subprogram, we might be passing P to another subprogram (but we |
| -- don't check that here), which might call P. P could modify |
| -- local variables, so we need to kill current values. It is |
| -- important not to do this for library-level subprograms, because |
| -- Kill_Current_Values is very inefficient in the case of library |
| -- level packages with lots of tagged types. |
| |
| if Is_Library_Level_Entity (Entity (Prefix (N))) then |
| null; |
| |
| -- Do not kill values on nodes initializing dispatch tables |
| -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access) |
| -- is currently generated by the expander only for this |
| -- purpose. Done to keep the quality of warnings currently |
| -- generated by the compiler (otherwise any declaration of |
| -- a tagged type cleans constant indications from its scope). |
| |
| elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion |
| and then (Etype (Parent (N)) = RTE (RE_Prim_Ptr) |
| or else |
| Etype (Parent (N)) = RTE (RE_Size_Ptr)) |
| and then Is_Dispatching_Operation |
| (Directly_Designated_Type (Etype (N))) |
| then |
| null; |
| |
| else |
| Kill_Current_Values; |
| end if; |
| |
| -- In the static elaboration model, treat the attribute reference |
| -- as a subprogram call for elaboration purposes. Suppress this |
| -- treatment under debug flag. In any case, we are all done. |
| |
| if Legacy_Elaboration_Checks |
| and not Dynamic_Elaboration_Checks |
| and not Debug_Flag_Dot_UU |
| then |
| Check_Elab_Call (N); |
| end if; |
| |
| return; |
| |
| -- Component is an operation of a protected type |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Is_Overloadable (Entity (Selector_Name (P))) |
| then |
| if Ekind (Entity (Selector_Name (P))) = E_Entry then |
| Error_Attr_P ("prefix of % attribute must be subprogram"); |
| end if; |
| |
| Build_Access_Subprogram_Type (Selector_Name (P)); |
| return; |
| end if; |
| |
| -- Deal with incorrect reference to a type, but note that some |
| -- accesses are allowed: references to the current type instance, |
| -- or in Ada 2005 self-referential pointer in a default-initialized |
| -- aggregate. |
| |
| if Is_Entity_Name (P) then |
| Typ := Entity (P); |
| |
| -- The reference may appear in an aggregate that has been expanded |
| -- into a loop. Locate scope of type definition, if any. |
| |
| Scop := Current_Scope; |
| while Ekind (Scop) = E_Loop loop |
| Scop := Scope (Scop); |
| end loop; |
| |
| if Is_Type (Typ) then |
| |
| -- OK if we are within the scope of a limited type |
| -- let's mark the component as having per object constraint |
| |
| if Is_Anonymous_Tagged_Base (Scop, Typ) then |
| Typ := Scop; |
| Set_Entity (P, Typ); |
| Set_Etype (P, Typ); |
| end if; |
| |
| if Typ = Scop then |
| declare |
| Q : Node_Id := Parent (N); |
| |
| begin |
| while Present (Q) |
| and then Nkind (Q) /= N_Component_Declaration |
| loop |
| Q := Parent (Q); |
| end loop; |
| |
| if Present (Q) then |
| Set_Has_Per_Object_Constraint |
| (Defining_Identifier (Q), True); |
| end if; |
| end; |
| |
| if Nkind (P) = N_Expanded_Name then |
| Error_Msg_F |
| ("current instance prefix must be a direct name", P); |
| end if; |
| |
| -- If a current instance attribute appears in a component |
| -- constraint it must appear alone; other contexts (spec- |
| -- expressions, within a task body) are not subject to this |
| -- restriction. |
| |
| if not In_Spec_Expression |
| and then not Has_Completion (Scop) |
| and then not |
| Nkind_In (Parent (N), N_Discriminant_Association, |
| N_Index_Or_Discriminant_Constraint) |
| then |
| Error_Msg_N |
| ("current instance attribute must appear alone", N); |
| end if; |
| |
| if Is_CPP_Class (Root_Type (Typ)) then |
| Error_Msg_N |
| ("??current instance unsupported for derivations of " |
| & "'C'P'P types", N); |
| end if; |
| |
| -- OK if we are in initialization procedure for the type |
| -- in question, in which case the reference to the type |
| -- is rewritten as a reference to the current object. |
| |
| elsif Ekind (Scop) = E_Procedure |
| and then Is_Init_Proc (Scop) |
| and then Etype (First_Formal (Scop)) = Typ |
| then |
| Rewrite (N, |
| Make_Attribute_Reference (Loc, |
| Prefix => Make_Identifier (Loc, Name_uInit), |
| Attribute_Name => Name_Unrestricted_Access)); |
| Analyze (N); |
| return; |
| |
| -- OK if a task type, this test needs sharpening up ??? |
| |
| elsif Is_Task_Type (Typ) then |
| null; |
| |
| -- OK if self-reference in an aggregate in Ada 2005, and |
| -- the reference comes from a copied default expression. |
| |
| -- Note that we check legality of self-reference even if the |
| -- expression comes from source, e.g. when a single component |
| -- association in an aggregate has a box association. |
| |
| elsif Ada_Version >= Ada_2005 |
| and then OK_Self_Reference |
| then |
| null; |
| |
| -- OK if reference to current instance of a protected object |
| |
| elsif Is_Protected_Self_Reference (P) then |
| null; |
| |
| -- Otherwise we have an error case |
| |
| else |
| Error_Attr ("% attribute cannot be applied to type", P); |
| return; |
| end if; |
| end if; |
| end if; |
| |
| -- If we fall through, we have a normal access to object case |
| |
| -- Unrestricted_Access is (for now) legal wherever an allocator would |
| -- be legal, so its Etype is set to E_Allocator. The expected type |
| -- of the other attributes is a general access type, and therefore |
| -- we label them with E_Access_Attribute_Type. |
| |
| if not Is_Overloaded (P) then |
| Acc_Type := Build_Access_Object_Type (P_Type); |
| Set_Etype (N, Acc_Type); |
| |
| else |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| begin |
| Set_Etype (N, Any_Type); |
| Get_First_Interp (P, Index, It); |
| while Present (It.Typ) loop |
| Acc_Type := Build_Access_Object_Type (It.Typ); |
| Add_One_Interp (N, Acc_Type, Acc_Type); |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| end if; |
| |
| -- Special cases when we can find a prefix that is an entity name |
| |
| declare |
| PP : Node_Id; |
| Ent : Entity_Id; |
| |
| begin |
| PP := P; |
| loop |
| if Is_Entity_Name (PP) then |
| Ent := Entity (PP); |
| |
| -- If we have an access to an object, and the attribute |
| -- comes from source, then set the object as potentially |
| -- source modified. We do this because the resulting access |
| -- pointer can be used to modify the variable, and we might |
| -- not detect this, leading to some junk warnings. |
| |
| -- We only do this for source references, since otherwise |
| -- we can suppress warnings, e.g. from the unrestricted |
| -- access generated for validity checks in -gnatVa mode. |
| |
| if Comes_From_Source (N) then |
| Set_Never_Set_In_Source (Ent, False); |
| end if; |
| |
| -- Mark entity as address taken in the case of |
| -- 'Unrestricted_Access or subprograms, and kill current |
| -- values. |
| |
| if Aname = Name_Unrestricted_Access |
| or else Is_Subprogram (Ent) |
| then |
| Set_Address_Taken (Ent); |
| end if; |
| |
| Kill_Current_Values (Ent); |
| exit; |
| |
| elsif Nkind_In (PP, N_Selected_Component, |
| N_Indexed_Component) |
| then |
| PP := Prefix (PP); |
| |
| else |
| exit; |
| end if; |
| end loop; |
| end; |
| end Analyze_Access_Attribute; |
| |
| ---------------------------------- |
| -- Analyze_Attribute_Old_Result -- |
| ---------------------------------- |
| |
| procedure Analyze_Attribute_Old_Result |
| (Legal : out Boolean; |
| Spec_Id : out Entity_Id) |
| is |
| procedure Check_Placement_In_Check (Prag : Node_Id); |
| -- Verify that the attribute appears within pragma Check that mimics |
| -- a postcondition. |
| |
| procedure Check_Placement_In_Contract_Cases (Prag : Node_Id); |
| -- Verify that the attribute appears within a consequence of aspect |
| -- or pragma Contract_Cases denoted by Prag. |
| |
| procedure Check_Placement_In_Test_Case (Prag : Node_Id); |
| -- Verify that the attribute appears within the "Ensures" argument of |
| -- aspect or pragma Test_Case denoted by Prag. |
| |
| function Is_Within |
| (Nod : Node_Id; |
| Encl_Nod : Node_Id) return Boolean; |
| -- Subsidiary to Check_Placemenet_In_XXX. Determine whether arbitrary |
| -- node Nod is within enclosing node Encl_Nod. |
| |
| procedure Placement_Error; |
| pragma No_Return (Placement_Error); |
| -- Emit a general error when the attributes does not appear in a |
| -- postcondition-like aspect or pragma, and then raises Bad_Attribute |
| -- to avoid any further semantic processing. |
| |
| ------------------------------ |
| -- Check_Placement_In_Check -- |
| ------------------------------ |
| |
| procedure Check_Placement_In_Check (Prag : Node_Id) is |
| Args : constant List_Id := Pragma_Argument_Associations (Prag); |
| Nam : constant Name_Id := Chars (Get_Pragma_Arg (First (Args))); |
| |
| begin |
| -- The "Name" argument of pragma Check denotes a postcondition |
| |
| if Nam_In (Nam, Name_Post, |
| Name_Post_Class, |
| Name_Postcondition, |
| Name_Refined_Post) |
| then |
| null; |
| |
| -- Otherwise the placement of the attribute is illegal |
| |
| else |
| Placement_Error; |
| end if; |
| end Check_Placement_In_Check; |
| |
| --------------------------------------- |
| -- Check_Placement_In_Contract_Cases -- |
| --------------------------------------- |
| |
| procedure Check_Placement_In_Contract_Cases (Prag : Node_Id) is |
| Arg : Node_Id; |
| Cases : Node_Id; |
| CCase : Node_Id; |
| |
| begin |
| -- Obtain the argument of the aspect or pragma |
| |
| if Nkind (Prag) = N_Aspect_Specification then |
| Arg := Prag; |
| else |
| Arg := First (Pragma_Argument_Associations (Prag)); |
| end if; |
| |
| Cases := Expression (Arg); |
| |
| if Present (Component_Associations (Cases)) then |
| CCase := First (Component_Associations (Cases)); |
| while Present (CCase) loop |
| |
| -- Detect whether the attribute appears within the |
| -- consequence of the current contract case. |
| |
| if Nkind (CCase) = N_Component_Association |
| and then Is_Within (N, Expression (CCase)) |
| then |
| return; |
| end if; |
| |
| Next (CCase); |
| end loop; |
| end if; |
| |
| -- Otherwise aspect or pragma Contract_Cases is either malformed |
| -- or the attribute does not appear within a consequence. |
| |
| Error_Attr |
| ("attribute % must appear in the consequence of a contract case", |
| P); |
| end Check_Placement_In_Contract_Cases; |
| |
| ---------------------------------- |
| -- Check_Placement_In_Test_Case -- |
| ---------------------------------- |
| |
| procedure Check_Placement_In_Test_Case (Prag : Node_Id) is |
| Arg : constant Node_Id := |
| Test_Case_Arg |
| (Prag => Prag, |
| Arg_Nam => Name_Ensures, |
| From_Aspect => Nkind (Prag) = N_Aspect_Specification); |
| |
| begin |
| -- Detect whether the attribute appears within the "Ensures" |
| -- expression of aspect or pragma Test_Case. |
| |
| if Present (Arg) and then Is_Within (N, Arg) then |
| null; |
| |
| else |
| Error_Attr |
| ("attribute % must appear in the ensures expression of a " |
| & "test case", P); |
| end if; |
| end Check_Placement_In_Test_Case; |
| |
| --------------- |
| -- Is_Within -- |
| --------------- |
| |
| function Is_Within |
| (Nod : Node_Id; |
| Encl_Nod : Node_Id) return Boolean |
| is |
| Par : Node_Id; |
| |
| begin |
| Par := Nod; |
| while Present (Par) loop |
| if Par = Encl_Nod then |
| return True; |
| |
| -- Prevent the search from going too far |
| |
| elsif Is_Body_Or_Package_Declaration (Par) then |
| exit; |
| end if; |
| |
| Par := Parent (Par); |
| end loop; |
| |
| return False; |
| end Is_Within; |
| |
| --------------------- |
| -- Placement_Error -- |
| --------------------- |
| |
| procedure Placement_Error is |
| begin |
| if Aname = Name_Old then |
| Error_Attr ("attribute % can only appear in postcondition", P); |
| |
| -- Specialize the error message for attribute 'Result |
| |
| else |
| Error_Attr |
| ("attribute % can only appear in postcondition of function", |
| P); |
| end if; |
| end Placement_Error; |
| |
| -- Local variables |
| |
| Prag : Node_Id; |
| Prag_Nam : Name_Id; |
| Subp_Decl : Node_Id; |
| |
| -- Start of processing for Analyze_Attribute_Old_Result |
| |
| begin |
| -- Assume that the attribute is illegal |
| |
| Legal := False; |
| Spec_Id := Empty; |
| |
| -- Traverse the parent chain to find the aspect or pragma where the |
| -- attribute resides. |
| |
| Prag := N; |
| while Present (Prag) loop |
| if Nkind_In (Prag, N_Aspect_Specification, N_Pragma) then |
| exit; |
| |
| -- Prevent the search from going too far |
| |
| elsif Is_Body_Or_Package_Declaration (Prag) then |
| exit; |
| end if; |
| |
| Prag := Parent (Prag); |
| end loop; |
| |
| -- The attribute is allowed to appear only in postcondition-like |
| -- aspects or pragmas. |
| |
| if Nkind_In (Prag, N_Aspect_Specification, N_Pragma) then |
| if Nkind (Prag) = N_Aspect_Specification then |
| Prag_Nam := Chars (Identifier (Prag)); |
| else |
| Prag_Nam := Pragma_Name (Prag); |
| end if; |
| |
| if Prag_Nam = Name_Check then |
| Check_Placement_In_Check (Prag); |
| |
| elsif Prag_Nam = Name_Contract_Cases then |
| Check_Placement_In_Contract_Cases (Prag); |
| |
| -- Attribute 'Result is allowed to appear in aspect or pragma |
| -- [Refined_]Depends (SPARK RM 6.1.5(11)). |
| |
| elsif Nam_In (Prag_Nam, Name_Depends, Name_Refined_Depends) |
| and then Aname = Name_Result |
| then |
| null; |
| |
| elsif Nam_In (Prag_Nam, Name_Post, |
| Name_Post_Class, |
| Name_Postcondition, |
| Name_Refined_Post) |
| then |
| null; |
| |
| elsif Prag_Nam = Name_Test_Case then |
| Check_Placement_In_Test_Case (Prag); |
| |
| else |
| Placement_Error; |
| return; |
| end if; |
| |
| -- Otherwise the placement of the attribute is illegal |
| |
| else |
| Placement_Error; |
| return; |
| end if; |
| |
| -- Find the related subprogram subject to the aspect or pragma |
| |
| if Nkind (Prag) = N_Aspect_Specification then |
| Subp_Decl := Parent (Prag); |
| else |
| Subp_Decl := Find_Related_Declaration_Or_Body (Prag); |
| end if; |
| |
| -- The aspect or pragma where the attribute resides should be |
| -- associated with a subprogram declaration or a body. If this is not |
| -- the case, then the aspect or pragma is illegal. Return as analysis |
| -- cannot be carried out. Note that it is legal to have the aspect |
| -- appear on a subprogram renaming, when the renamed entity is an |
| -- attribute reference. |
| |
| -- Generating C code the internally built nested _postcondition |
| -- subprograms are inlined; after expanded, inlined aspects are |
| -- located in the internal block generated by the frontend. |
| |
| if Nkind (Subp_Decl) = N_Block_Statement |
| and then Modify_Tree_For_C |
| and then In_Inlined_Body |
| then |
| null; |
| |
| elsif not Nkind_In (Subp_Decl, N_Abstract_Subprogram_Declaration, |
| N_Entry_Declaration, |
| N_Expression_Function, |
| N_Generic_Subprogram_Declaration, |
| N_Subprogram_Body, |
| N_Subprogram_Body_Stub, |
| N_Subprogram_Declaration, |
| N_Subprogram_Renaming_Declaration) |
| then |
| return; |
| end if; |
| |
| -- If we get here, then the attribute is legal |
| |
| Legal := True; |
| Spec_Id := Unique_Defining_Entity (Subp_Decl); |
| |
| -- When generating C code, nested _postcondition subprograms are |
| -- inlined by the front end to avoid problems (when unnested) with |
| -- referenced itypes. Handle that here, since as part of inlining the |
| -- expander nests subprogram within a dummy procedure named _parent |
| -- (see Build_Postconditions_Procedure and Build_Body_To_Inline). |
| -- Hence, in this context, the spec_id of _postconditions is the |
| -- enclosing scope. |
| |
| if Modify_Tree_For_C |
| and then Chars (Spec_Id) = Name_uParent |
| and then Chars (Scope (Spec_Id)) = Name_uPostconditions |
| then |
| -- This situation occurs only when preanalyzing the inlined body |
| |
| pragma Assert (not Full_Analysis); |
| |
| Spec_Id := Scope (Spec_Id); |
| pragma Assert (Is_Inlined (Spec_Id)); |
| end if; |
| end Analyze_Attribute_Old_Result; |
| |
| ----------------------------- |
| -- Analyze_Image_Attribute -- |
| ----------------------------- |
| |
| procedure Analyze_Image_Attribute (Str_Typ : Entity_Id) is |
| begin |
| Check_SPARK_05_Restriction_On_Attribute; |
| |
| -- AI12-00124: The ARG has adopted the GNAT semantics of 'Img for |
| -- scalar types, so that the prefix can be an object, a named value, |
| -- or a type, and there is no need for an argument in this case. |
| |
| if Attr_Id = Attribute_Img |
| or else (Ada_Version > Ada_2005 and then Is_Object_Image (P)) |
| then |
| Check_E0; |
| Set_Etype (N, Str_Typ); |
| |
| if Attr_Id = Attribute_Img and then not Is_Object_Image (P) then |
| Error_Attr_P |
| ("prefix of % attribute must be a scalar object name"); |
| end if; |
| else |
| Check_E1; |
| Set_Etype (N, Str_Typ); |
| |
| -- Check that the prefix type is scalar - much in the same way as |
| -- Check_Scalar_Type but with custom error messages to denote the |
| -- variants of 'Image attributes. |
| |
| if Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| and then Ekind (Entity (P)) = E_Incomplete_Type |
| and then Present (Full_View (Entity (P))) |
| then |
| P_Type := Full_View (Entity (P)); |
| Set_Entity (P, P_Type); |
| end if; |
| |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| or else not Is_Scalar_Type (P_Type) |
| then |
| if Ada_Version > Ada_2005 then |
| Error_Attr_P |
| ("prefix of % attribute must be a scalar type or a scalar " |
| & "object name"); |
| else |
| Error_Attr_P ("prefix of % attribute must be a scalar type"); |
| end if; |
| |
| elsif Is_Protected_Self_Reference (P) then |
| Error_Attr_P |
| ("prefix of % attribute denotes current instance " |
| & "(RM 9.4(21/2))"); |
| end if; |
| |
| Resolve (E1, P_Base_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| end if; |
| |
| Check_Enum_Image; |
| |
| -- Check restriction No_Fixed_IO. Note the check of Comes_From_Source |
| -- to avoid giving a duplicate message for when Image attributes |
| -- applied to object references get expanded into type-based Image |
| -- attributes. |
| |
| if Restriction_Check_Required (No_Fixed_IO) |
| and then Comes_From_Source (N) |
| and then Is_Fixed_Point_Type (P_Type) |
| then |
| Check_Restriction (No_Fixed_IO, P); |
| end if; |
| end Analyze_Image_Attribute; |
| |
| --------------------------------- |
| -- Bad_Attribute_For_Predicate -- |
| --------------------------------- |
| |
| procedure Bad_Attribute_For_Predicate is |
| begin |
| if Is_Scalar_Type (P_Type) |
| and then Comes_From_Source (N) |
| then |
| Error_Msg_Name_1 := Aname; |
| Bad_Predicated_Subtype_Use |
| ("type& has predicates, attribute % not allowed", N, P_Type); |
| end if; |
| end Bad_Attribute_For_Predicate; |
| |
| -------------------------------- |
| -- Check_Array_Or_Scalar_Type -- |
| -------------------------------- |
| |
| procedure Check_Array_Or_Scalar_Type is |
| function In_Aspect_Specification return Boolean; |
| -- A current instance of a type in an aspect specification is an |
| -- object and not a type, and therefore cannot be of a scalar type |
| -- in the prefix of one of the array attributes if the attribute |
| -- reference is part of an aspect expression. |
| |
| ----------------------------- |
| -- In_Aspect_Specification -- |
| ----------------------------- |
| |
| function In_Aspect_Specification return Boolean is |
| P : Node_Id; |
| |
| begin |
| P := Parent (N); |
| while Present (P) loop |
| if Nkind (P) = N_Aspect_Specification then |
| return P_Type = Entity (P); |
| |
| elsif Nkind (P) in N_Declaration then |
| return False; |
| end if; |
| |
| P := Parent (P); |
| end loop; |
| |
| return False; |
| end In_Aspect_Specification; |
| |
| -- Local variables |
| |
| Dims : Int; |
| Index : Entity_Id; |
| |
| -- Start of processing for Check_Array_Or_Scalar_Type |
| |
| begin |
| -- Case of string literal or string literal subtype. These cases |
| -- cannot arise from legal Ada code, but the expander is allowed |
| -- to generate them. They require special handling because string |
| -- literal subtypes do not have standard bounds (the whole idea |
| -- of these subtypes is to avoid having to generate the bounds) |
| |
| if Ekind (P_Type) = E_String_Literal_Subtype then |
| Set_Etype (N, Etype (First_Index (P_Base_Type))); |
| return; |
| |
| -- Scalar types |
| |
| elsif Is_Scalar_Type (P_Type) then |
| Check_Type; |
| |
| if Present (E1) then |
| Error_Attr ("invalid argument in % attribute", E1); |
| |
| elsif In_Aspect_Specification then |
| Error_Attr |
| ("prefix of % attribute cannot be the current instance of a " |
| & "scalar type", P); |
| |
| else |
| Set_Etype (N, P_Base_Type); |
| return; |
| end if; |
| |
| -- The following is a special test to allow 'First to apply to |
| -- private scalar types if the attribute comes from generated |
| -- code. This occurs in the case of Normalize_Scalars code. |
| |
| elsif Is_Private_Type (P_Type) |
| and then Present (Full_View (P_Type)) |
| and then Is_Scalar_Type (Full_View (P_Type)) |
| and then not Comes_From_Source (N) |
| then |
| Set_Etype (N, Implementation_Base_Type (P_Type)); |
| |
| -- Array types other than string literal subtypes handled above |
| |
| else |
| Check_Array_Type; |
| |
| -- We know prefix is an array type, or the name of an array |
| -- object, and that the expression, if present, is static |
| -- and within the range of the dimensions of the type. |
| |
| pragma Assert (Is_Array_Type (P_Type)); |
| Index := First_Index (P_Base_Type); |
| |
| if No (E1) then |
| |
| -- First dimension assumed |
| |
| Set_Etype (N, Base_Type (Etype (Index))); |
| |
| else |
| Dims := UI_To_Int (Intval (E1)); |
| |
| for J in 1 .. Dims - 1 loop |
| Next_Index (Index); |
| end loop; |
| |
| Set_Etype (N, Base_Type (Etype (Index))); |
| Set_Etype (E1, Standard_Integer); |
| end if; |
| end if; |
| end Check_Array_Or_Scalar_Type; |
| |
| ---------------------- |
| -- Check_Array_Type -- |
| ---------------------- |
| |
| procedure Check_Array_Type is |
| D : Int; |
| -- Dimension number for array attributes |
| |
| begin |
| -- If the type is a string literal type, then this must be generated |
| -- internally, and no further check is required on its legality. |
| |
| if Ekind (P_Type) = E_String_Literal_Subtype then |
| return; |
| |
| -- If the type is a composite, it is an illegal aggregate, no point |
| -- in going on. |
| |
| elsif P_Type = Any_Composite then |
| raise Bad_Attribute; |
| end if; |
| |
| -- Normal case of array type or subtype |
| |
| Check_Either_E0_Or_E1; |
| Check_Dereference; |
| |
| if Is_Array_Type (P_Type) then |
| if not Is_Constrained (P_Type) |
| and then Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| -- Note: we do not call Error_Attr here, since we prefer to |
| -- continue, using the relevant index type of the array, |
| -- even though it is unconstrained. This gives better error |
| -- recovery behavior. |
| |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_F |
| ("prefix for % attribute must be constrained array", P); |
| end if; |
| |
| -- The attribute reference freezes the type, and thus the |
| -- component type, even if the attribute may not depend on the |
| -- component. Diagnose arrays with incomplete components now. |
| -- If the prefix is an access to array, this does not freeze |
| -- the designated type. |
| |
| if Nkind (P) /= N_Explicit_Dereference then |
| Check_Fully_Declared (Component_Type (P_Type), P); |
| end if; |
| |
| D := Number_Dimensions (P_Type); |
| |
| else |
| if Is_Private_Type (P_Type) then |
| Error_Attr_P ("prefix for % attribute may not be private type"); |
| |
| elsif Is_Access_Type (P_Type) |
| and then Is_Array_Type (Designated_Type (P_Type)) |
| and then Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| Error_Attr_P ("prefix of % attribute cannot be access type"); |
| |
| elsif Attr_Id = Attribute_First |
| or else |
| Attr_Id = Attribute_Last |
| then |
| Error_Attr ("invalid prefix for % attribute", P); |
| |
| else |
| Error_Attr_P ("prefix for % attribute must be array"); |
| end if; |
| end if; |
| |
| if Present (E1) then |
| Resolve (E1, Any_Integer); |
| Set_Etype (E1, Standard_Integer); |
| |
| if not Is_OK_Static_Expression (E1) |
| or else Raises_Constraint_Error (E1) |
| then |
| Flag_Non_Static_Expr |
| ("expression for dimension must be static!", E1); |
| Error_Attr; |
| |
| elsif UI_To_Int (Expr_Value (E1)) > D |
| or else UI_To_Int (Expr_Value (E1)) < 1 |
| then |
| Error_Attr ("invalid dimension number for array type", E1); |
| end if; |
| end if; |
| |
| if (Style_Check and Style_Check_Array_Attribute_Index) |
| and then Comes_From_Source (N) |
| then |
| Style.Check_Array_Attribute_Index (N, E1, D); |
| end if; |
| end Check_Array_Type; |
| |
| ------------------------- |
| -- Check_Asm_Attribute -- |
| ------------------------- |
| |
| procedure Check_Asm_Attribute is |
| begin |
| Check_Type; |
| Check_E2; |
| |
| -- Check first argument is static string expression |
| |
| Analyze_And_Resolve (E1, Standard_String); |
| |
| if Etype (E1) = Any_Type then |
| return; |
| |
| elsif not Is_OK_Static_Expression (E1) then |
| Flag_Non_Static_Expr |
| ("constraint argument must be static string expression!", E1); |
| Error_Attr; |
| end if; |
| |
| -- Check second argument is right type |
| |
| Analyze_And_Resolve (E2, Entity (P)); |
| |
| -- Note: that is all we need to do, we don't need to check |
| -- that it appears in a correct context. The Ada type system |
| -- will do that for us. |
| |
| end Check_Asm_Attribute; |
| |
| --------------------- |
| -- Check_Component -- |
| --------------------- |
| |
| procedure Check_Component is |
| begin |
| Check_E0; |
| |
| if Nkind (P) /= N_Selected_Component |
| or else |
| (Ekind (Entity (Selector_Name (P))) /= E_Component |
| and then |
| Ekind (Entity (Selector_Name (P))) /= E_Discriminant) |
| then |
| Error_Attr_P ("prefix for % attribute must be selected component"); |
| end if; |
| end Check_Component; |
| |
| ------------------------------------ |
| -- Check_Decimal_Fixed_Point_Type -- |
| ------------------------------------ |
| |
| procedure Check_Decimal_Fixed_Point_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Decimal_Fixed_Point_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be decimal type"); |
| end if; |
| end Check_Decimal_Fixed_Point_Type; |
| |
| ----------------------- |
| -- Check_Dereference -- |
| ----------------------- |
| |
| procedure Check_Dereference is |
| begin |
| |
| -- Case of a subtype mark |
| |
| if Is_Entity_Name (P) and then Is_Type (Entity (P)) then |
| return; |
| end if; |
| |
| -- Case of an expression |
| |
| Resolve (P); |
| |
| if Is_Access_Type (P_Type) then |
| |
| -- If there is an implicit dereference, then we must freeze the |
| -- designated type of the access type, since the type of the |
| -- referenced array is this type (see AI95-00106). |
| |
| -- As done elsewhere, freezing must not happen when preanalyzing |
| -- a pre- or postcondition or a default value for an object or for |
| -- a formal parameter. |
| |
| if not In_Spec_Expression then |
| Freeze_Before (N, Designated_Type (P_Type)); |
| end if; |
| |
| Rewrite (P, |
| Make_Explicit_Dereference (Sloc (P), |
| Prefix => Relocate_Node (P))); |
| |
| Analyze_And_Resolve (P); |
| P_Type := Etype (P); |
| |
| if P_Type = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| |
| P_Base_Type := Base_Type (P_Type); |
| end if; |
| end Check_Dereference; |
| |
| ------------------------- |
| -- Check_Discrete_Type -- |
| ------------------------- |
| |
| procedure Check_Discrete_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Discrete_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be discrete type"); |
| end if; |
| end Check_Discrete_Type; |
| |
| -------------- |
| -- Check_E0 -- |
| -------------- |
| |
| procedure Check_E0 is |
| begin |
| if Present (E1) then |
| Unexpected_Argument (E1); |
| end if; |
| end Check_E0; |
| |
| -------------- |
| -- Check_E1 -- |
| -------------- |
| |
| procedure Check_E1 is |
| begin |
| Check_Either_E0_Or_E1; |
| |
| if No (E1) then |
| |
| -- Special-case attributes that are functions and that appear as |
| -- the prefix of another attribute. Error is posted on parent. |
| |
| if Nkind (Parent (N)) = N_Attribute_Reference |
| and then Nam_In (Attribute_Name (Parent (N)), Name_Address, |
| Name_Code_Address, |
| Name_Access) |
| then |
| Error_Msg_Name_1 := Attribute_Name (Parent (N)); |
| Error_Msg_N ("illegal prefix for % attribute", Parent (N)); |
| Set_Etype (Parent (N), Any_Type); |
| Set_Entity (Parent (N), Any_Type); |
| raise Bad_Attribute; |
| |
| else |
| Error_Attr ("missing argument for % attribute", N); |
| end if; |
| end if; |
| end Check_E1; |
| |
| -------------- |
| -- Check_E2 -- |
| -------------- |
| |
| procedure Check_E2 is |
| begin |
| if No (E1) then |
| Error_Attr ("missing arguments for % attribute (2 required)", N); |
| elsif No (E2) then |
| Error_Attr ("missing argument for % attribute (2 required)", N); |
| end if; |
| end Check_E2; |
| |
| --------------------------- |
| -- Check_Either_E0_Or_E1 -- |
| --------------------------- |
| |
| procedure Check_Either_E0_Or_E1 is |
| begin |
| if Present (E2) then |
| Unexpected_Argument (E2); |
| end if; |
| end Check_Either_E0_Or_E1; |
| |
| ---------------------- |
| -- Check_Enum_Image -- |
| ---------------------- |
| |
| procedure Check_Enum_Image is |
| Lit : Entity_Id; |
| |
| begin |
| -- When an enumeration type appears in an attribute reference, all |
| -- literals of the type are marked as referenced. This must only be |
| -- done if the attribute reference appears in the current source. |
| -- Otherwise the information on references may differ between a |
| -- normal compilation and one that performs inlining. |
| |
| if Is_Enumeration_Type (P_Base_Type) |
| and then In_Extended_Main_Code_Unit (N) |
| then |
| Lit := First_Literal (P_Base_Type); |
| while Present (Lit) loop |
| Set_Referenced (Lit); |
| Next_Literal (Lit); |
| end loop; |
| end if; |
| end Check_Enum_Image; |
| |
| ---------------------------- |
| -- Check_First_Last_Valid -- |
| ---------------------------- |
| |
| procedure Check_First_Last_Valid is |
| begin |
| Check_Discrete_Type; |
| |
| -- Freeze the subtype now, so that the following test for predicates |
| -- works (we set the predicates stuff up at freeze time) |
| |
| Insert_Actions (N, Freeze_Entity (P_Type, P)); |
| |
| -- Now test for dynamic predicate |
| |
| if Has_Predicates (P_Type) |
| and then not (Has_Static_Predicate (P_Type)) |
| then |
| Error_Attr_P |
| ("prefix of % attribute may not have dynamic predicate"); |
| end if; |
| |
| -- Check non-static subtype |
| |
| if not Is_OK_Static_Subtype (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be a static subtype"); |
| end if; |
| |
| -- Test case for no values |
| |
| if Expr_Value (Type_Low_Bound (P_Type)) > |
| Expr_Value (Type_High_Bound (P_Type)) |
| or else (Has_Predicates (P_Type) |
| and then |
| Is_Empty_List (Static_Discrete_Predicate (P_Type))) |
| then |
| Error_Attr_P |
| ("prefix of % attribute must be subtype with at least one " |
| & "value"); |
| end if; |
| end Check_First_Last_Valid; |
| |
| ---------------------------- |
| -- Check_Fixed_Point_Type -- |
| ---------------------------- |
| |
| procedure Check_Fixed_Point_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Fixed_Point_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be fixed point type"); |
| end if; |
| end Check_Fixed_Point_Type; |
| |
| ------------------------------ |
| -- Check_Fixed_Point_Type_0 -- |
| ------------------------------ |
| |
| procedure Check_Fixed_Point_Type_0 is |
| begin |
| Check_Fixed_Point_Type; |
| Check_E0; |
| end Check_Fixed_Point_Type_0; |
| |
| ------------------------------- |
| -- Check_Floating_Point_Type -- |
| ------------------------------- |
| |
| procedure Check_Floating_Point_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Floating_Point_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be float type"); |
| end if; |
| end Check_Floating_Point_Type; |
| |
| --------------------------------- |
| -- Check_Floating_Point_Type_0 -- |
| --------------------------------- |
| |
| procedure Check_Floating_Point_Type_0 is |
| begin |
| Check_Floating_Point_Type; |
| Check_E0; |
| end Check_Floating_Point_Type_0; |
| |
| --------------------------------- |
| -- Check_Floating_Point_Type_1 -- |
| --------------------------------- |
| |
| procedure Check_Floating_Point_Type_1 is |
| begin |
| Check_Floating_Point_Type; |
| Check_E1; |
| end Check_Floating_Point_Type_1; |
| |
| --------------------------------- |
| -- Check_Floating_Point_Type_2 -- |
| --------------------------------- |
| |
| procedure Check_Floating_Point_Type_2 is |
| begin |
| Check_Floating_Point_Type; |
| Check_E2; |
| end Check_Floating_Point_Type_2; |
| |
| ------------------------ |
| -- Check_Integer_Type -- |
| ------------------------ |
| |
| procedure Check_Integer_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Integer_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be integer type"); |
| end if; |
| end Check_Integer_Type; |
| |
| -------------------------------- |
| -- Check_Modular_Integer_Type -- |
| -------------------------------- |
| |
| procedure Check_Modular_Integer_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Modular_Integer_Type (P_Type) then |
| Error_Attr_P |
| ("prefix of % attribute must be modular integer type"); |
| end if; |
| end Check_Modular_Integer_Type; |
| |
| ------------------------ |
| -- Check_Not_CPP_Type -- |
| ------------------------ |
| |
| procedure Check_Not_CPP_Type is |
| begin |
| if Is_Tagged_Type (Etype (P)) |
| and then Convention (Etype (P)) = Convention_CPP |
| and then Is_CPP_Class (Root_Type (Etype (P))) |
| then |
| Error_Attr_P |
| ("invalid use of % attribute with 'C'P'P tagged type"); |
| end if; |
| end Check_Not_CPP_Type; |
| |
| ------------------------------- |
| -- Check_Not_Incomplete_Type -- |
| ------------------------------- |
| |
| procedure Check_Not_Incomplete_Type is |
| E : Entity_Id; |
| Typ : Entity_Id; |
| |
| begin |
| -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit |
| -- dereference we have to check wrong uses of incomplete types |
| -- (other wrong uses are checked at their freezing point). |
| |
| -- In Ada 2012, incomplete types can appear in subprogram |
| -- profiles, but formals with incomplete types cannot be the |
| -- prefix of attributes. |
| |
| -- Example 1: Limited-with |
| |
| -- limited with Pkg; |
| -- package P is |
| -- type Acc is access Pkg.T; |
| -- X : Acc; |
| -- S : Integer := X.all'Size; -- ERROR |
| -- end P; |
| |
| -- Example 2: Tagged incomplete |
| |
| -- type T is tagged; |
| -- type Acc is access all T; |
| -- X : Acc; |
| -- S : constant Integer := X.all'Size; -- ERROR |
| -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR |
| |
| if Ada_Version >= Ada_2005 |
| and then Nkind (P) = N_Explicit_Dereference |
| then |
| E := P; |
| while Nkind (E) = N_Explicit_Dereference loop |
| E := Prefix (E); |
| end loop; |
| |
| Typ := Etype (E); |
| |
| if From_Limited_With (Typ) then |
| Error_Attr_P |
| ("prefix of % attribute cannot be an incomplete type"); |
| |
| -- If the prefix is an access type check the designated type |
| |
| elsif Is_Access_Type (Typ) |
| and then Nkind (P) = N_Explicit_Dereference |
| then |
| Typ := Directly_Designated_Type (Typ); |
| end if; |
| |
| if Is_Class_Wide_Type (Typ) then |
| Typ := Root_Type (Typ); |
| end if; |
| |
| -- A legal use of a shadow entity occurs only when the unit where |
| -- the non-limited view resides is imported via a regular with |
| -- clause in the current body. Such references to shadow entities |
| -- may occur in subprogram formals. |
| |
| if Is_Incomplete_Type (Typ) |
| and then From_Limited_With (Typ) |
| and then Present (Non_Limited_View (Typ)) |
| and then Is_Legal_Shadow_Entity_In_Body (Typ) |
| then |
| Typ := Non_Limited_View (Typ); |
| end if; |
| |
| -- If still incomplete, it can be a local incomplete type, or a |
| -- limited view whose scope is also a limited view. |
| |
| if Ekind (Typ) = E_Incomplete_Type then |
| if not From_Limited_With (Typ) |
| and then No (Full_View (Typ)) |
| then |
| Error_Attr_P |
| ("prefix of % attribute cannot be an incomplete type"); |
| |
| -- The limited view may be available indirectly through |
| -- an intermediate unit. If the non-limited view is available |
| -- the attribute reference is legal. |
| |
| elsif From_Limited_With (Typ) |
| and then |
| (No (Non_Limited_View (Typ)) |
| or else Is_Incomplete_Type (Non_Limited_View (Typ))) |
| then |
| Error_Attr_P |
| ("prefix of % attribute cannot be an incomplete type"); |
| end if; |
| end if; |
| |
| -- Ada 2012 : formals in bodies may be incomplete, but no attribute |
| -- legally applies. |
| |
| elsif Is_Entity_Name (P) |
| and then Is_Formal (Entity (P)) |
| and then Is_Incomplete_Type (Etype (Etype (P))) |
| then |
| Error_Attr_P |
| ("prefix of % attribute cannot be an incomplete type"); |
| end if; |
| |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| or else In_Spec_Expression |
| then |
| return; |
| else |
| Check_Fully_Declared (P_Type, P); |
| end if; |
| end Check_Not_Incomplete_Type; |
| |
| ---------------------------- |
| -- Check_Object_Reference -- |
| ---------------------------- |
| |
| procedure Check_Object_Reference (P : Node_Id) is |
| Rtyp : Entity_Id; |
| |
| begin |
| -- If we need an object, and we have a prefix that is the name of a |
| -- function entity, convert it into a function call. |
| |
| if Is_Entity_Name (P) |
| and then Ekind (Entity (P)) = E_Function |
| then |
| Rtyp := Etype (Entity (P)); |
| |
| Rewrite (P, |
| Make_Function_Call (Sloc (P), |
| Name => Relocate_Node (P))); |
| |
| Analyze_And_Resolve (P, Rtyp); |
| |
| -- Otherwise we must have an object reference |
| |
| elsif not Is_Object_Reference (P) then |
| Error_Attr_P ("prefix of % attribute must be object"); |
| end if; |
| end Check_Object_Reference; |
| |
| ---------------------------- |
| -- Check_PolyORB_Attribute -- |
| ---------------------------- |
| |
| procedure Check_PolyORB_Attribute is |
| begin |
| Validate_Non_Static_Attribute_Function_Call; |
| |
| Check_Type; |
| Check_Not_CPP_Type; |
| |
| if Get_PCS_Name /= Name_PolyORB_DSA then |
| Error_Attr |
| ("attribute% requires the 'Poly'O'R'B 'P'C'S", N); |
| end if; |
| end Check_PolyORB_Attribute; |
| |
| ------------------------ |
| -- Check_Program_Unit -- |
| ------------------------ |
| |
| procedure Check_Program_Unit is |
| begin |
| if Is_Entity_Name (P) then |
| declare |
| K : constant Entity_Kind := Ekind (Entity (P)); |
| T : constant Entity_Id := Etype (Entity (P)); |
| |
| begin |
| if K in Subprogram_Kind |
| or else K in Task_Kind |
| or else K in Protected_Kind |
| or else K = E_Package |
| or else K in Generic_Unit_Kind |
| or else (K = E_Variable |
| and then |
| (Is_Task_Type (T) |
| or else |
| Is_Protected_Type (T))) |
| then |
| return; |
| end if; |
| end; |
| end if; |
| |
| Error_Attr_P ("prefix of % attribute must be program unit"); |
| end Check_Program_Unit; |
| |
| --------------------- |
| -- Check_Real_Type -- |
| --------------------- |
| |
| procedure Check_Real_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Real_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be real type"); |
| end if; |
| end Check_Real_Type; |
| |
| ----------------------- |
| -- Check_Scalar_Type -- |
| ----------------------- |
| |
| procedure Check_Scalar_Type is |
| begin |
| Check_Type; |
| |
| if not Is_Scalar_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be scalar type"); |
| end if; |
| end Check_Scalar_Type; |
| |
| ------------------------------------------ |
| -- Check_SPARK_05_Restriction_On_Attribute -- |
| ------------------------------------------ |
| |
| procedure Check_SPARK_05_Restriction_On_Attribute is |
| begin |
| Error_Msg_Name_1 := Aname; |
| Check_SPARK_05_Restriction ("attribute % is not allowed", P); |
| end Check_SPARK_05_Restriction_On_Attribute; |
| |
| --------------------------- |
| -- Check_Standard_Prefix -- |
| --------------------------- |
| |
| procedure Check_Standard_Prefix is |
| begin |
| Check_E0; |
| |
| if Nkind (P) /= N_Identifier or else Chars (P) /= Name_Standard then |
| Error_Attr ("only allowed prefix for % attribute is Standard", P); |
| end if; |
| end Check_Standard_Prefix; |
| |
| ---------------------------- |
| -- Check_Stream_Attribute -- |
| ---------------------------- |
| |
| procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is |
| Etyp : Entity_Id; |
| Btyp : Entity_Id; |
| |
| In_Shared_Var_Procs : Boolean; |
| -- True when compiling System.Shared_Storage.Shared_Var_Procs body. |
| -- For this runtime package (always compiled in GNAT mode), we allow |
| -- stream attributes references for limited types for the case where |
| -- shared passive objects are implemented using stream attributes, |
| -- which is the default in GNAT's persistent storage implementation. |
| |
| begin |
| Validate_Non_Static_Attribute_Function_Call; |
| |
| -- With the exception of 'Input, Stream attributes are procedures, |
| -- and can only appear at the position of procedure calls. We check |
| -- for this here, before they are rewritten, to give a more precise |
| -- diagnostic. |
| |
| if Nam = TSS_Stream_Input then |
| null; |
| |
| elsif Is_List_Member (N) |
| and then not Nkind_In (Parent (N), N_Procedure_Call_Statement, |
| N_Aggregate) |
| then |
| null; |
| |
| else |
| Error_Attr |
| ("invalid context for attribute%, which is a procedure", N); |
| end if; |
| |
| Check_Type; |
| Btyp := Implementation_Base_Type (P_Type); |
| |
| -- Stream attributes not allowed on limited types unless the |
| -- attribute reference was generated by the expander (in which |
| -- case the underlying type will be used, as described in Sinfo), |
| -- or the attribute was specified explicitly for the type itself |
| -- or one of its ancestors (taking visibility rules into account if |
| -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp |
| -- (with no visibility restriction). |
| |
| declare |
| Gen_Body : constant Node_Id := Enclosing_Generic_Body (N); |
| begin |
| if Present (Gen_Body) then |
| In_Shared_Var_Procs := |
| Is_RTE (Corresponding_Spec (Gen_Body), RE_Shared_Var_Procs); |
| else |
| In_Shared_Var_Procs := False; |
| end if; |
| end; |
| |
| if (Comes_From_Source (N) |
| and then not (In_Shared_Var_Procs or In_Instance)) |
| and then not Stream_Attribute_Available (P_Type, Nam) |
| and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert) |
| then |
| Error_Msg_Name_1 := Aname; |
| |
| if Is_Limited_Type (P_Type) then |
| Error_Msg_NE |
| ("limited type& has no% attribute", P, P_Type); |
| Explain_Limited_Type (P_Type, P); |
| else |
| Error_Msg_NE |
| ("attribute% for type& is not available", P, P_Type); |
| end if; |
| end if; |
| |
| -- Check for no stream operations allowed from No_Tagged_Streams |
| |
| if Is_Tagged_Type (P_Type) |
| and then Present (No_Tagged_Streams_Pragma (P_Type)) |
| then |
| Error_Msg_Sloc := Sloc (No_Tagged_Streams_Pragma (P_Type)); |
| Error_Msg_NE |
| ("no stream operations for & (No_Tagged_Streams #)", N, P_Type); |
| return; |
| end if; |
| |
| -- Check restriction violations |
| |
| -- First check the No_Streams restriction, which prohibits the use |
| -- of explicit stream attributes in the source program. We do not |
| -- prevent the occurrence of stream attributes in generated code, |
| -- for instance those generated implicitly for dispatching purposes. |
| |
| if Comes_From_Source (N) then |
| Check_Restriction (No_Streams, P); |
| end if; |
| |
| -- AI05-0057: if restriction No_Default_Stream_Attributes is active, |
| -- it is illegal to use a predefined elementary type stream attribute |
| -- either by itself, or more importantly as part of the attribute |
| -- subprogram for a composite type. However, if the broader |
| -- restriction No_Streams is active, stream operations are not |
| -- generated, and there is no error. |
| |
| if Restriction_Active (No_Default_Stream_Attributes) |
| and then not Restriction_Active (No_Streams) |
| then |
| declare |
| T : Entity_Id; |
| |
| begin |
| if Nam = TSS_Stream_Input |
| or else |
| Nam = TSS_Stream_Read |
| then |
| T := |
| Type_Without_Stream_Operation (P_Type, TSS_Stream_Read); |
| else |
| T := |
| Type_Without_Stream_Operation (P_Type, TSS_Stream_Write); |
| end if; |
| |
| if Present (T) then |
| Check_Restriction (No_Default_Stream_Attributes, N); |
| |
| Error_Msg_NE |
| ("missing user-defined Stream Read or Write for type&", |
| N, T); |
| if not Is_Elementary_Type (P_Type) then |
| Error_Msg_NE |
| ("\which is a component of type&", N, P_Type); |
| end if; |
| end if; |
| end; |
| end if; |
| |
| -- Check special case of Exception_Id and Exception_Occurrence which |
| -- are not allowed for restriction No_Exception_Registration. |
| |
| if Restriction_Check_Required (No_Exception_Registration) |
| and then (Is_RTE (P_Type, RE_Exception_Id) |
| or else |
| Is_RTE (P_Type, RE_Exception_Occurrence)) |
| then |
| Check_Restriction (No_Exception_Registration, P); |
| end if; |
| |
| -- Here we must check that the first argument is an access type |
| -- that is compatible with Ada.Streams.Root_Stream_Type'Class. |
| |
| Analyze_And_Resolve (E1); |
| Etyp := Etype (E1); |
| |
| -- Note: the double call to Root_Type here is needed because the |
| -- root type of a class-wide type is the corresponding type (e.g. |
| -- X for X'Class, and we really want to go to the root.) |
| |
| if not Is_Access_Type (Etyp) |
| or else Root_Type (Root_Type (Designated_Type (Etyp))) /= |
| RTE (RE_Root_Stream_Type) |
| then |
| Error_Attr |
| ("expected access to Ada.Streams.Root_Stream_Type''Class", E1); |
| end if; |
| |
| -- Check that the second argument is of the right type if there is |
| -- one (the Input attribute has only one argument so this is skipped) |
| |
| if Present (E2) then |
| Analyze (E2); |
| |
| if Nam = TSS_Stream_Read |
| and then not Is_OK_Variable_For_Out_Formal (E2) |
| then |
| Error_Attr |
| ("second argument of % attribute must be a variable", E2); |
| end if; |
| |
| Resolve (E2, P_Type); |
| end if; |
| |
| Check_Not_CPP_Type; |
| end Check_Stream_Attribute; |
| |
| ------------------------- |
| -- Check_System_Prefix -- |
| ------------------------- |
| |
| procedure Check_System_Prefix is |
| begin |
| if Nkind (P) /= N_Identifier or else Chars (P) /= Name_System then |
| Error_Attr ("only allowed prefix for % attribute is System", P); |
| end if; |
| end Check_System_Prefix; |
| |
| ----------------------- |
| -- Check_Task_Prefix -- |
| ----------------------- |
| |
| procedure Check_Task_Prefix is |
| begin |
| Analyze (P); |
| |
| -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to |
| -- task interface class-wide types. |
| |
| if Is_Task_Type (Etype (P)) |
| or else (Is_Access_Type (Etype (P)) |
| and then Is_Task_Type (Designated_Type (Etype (P)))) |
| or else (Ada_Version >= Ada_2005 |
| and then Ekind (Etype (P)) = E_Class_Wide_Type |
| and then Is_Interface (Etype (P)) |
| and then Is_Task_Interface (Etype (P))) |
| then |
| Resolve (P); |
| |
| else |
| if Ada_Version >= Ada_2005 then |
| Error_Attr_P |
| ("prefix of % attribute must be a task or a task " & |
| "interface class-wide object"); |
| |
| else |
| Error_Attr_P ("prefix of % attribute must be a task"); |
| end if; |
| end if; |
| end Check_Task_Prefix; |
| |
| ---------------- |
| -- Check_Type -- |
| ---------------- |
| |
| -- The possibilities are an entity name denoting a type, or an |
| -- attribute reference that denotes a type (Base or Class). If |
| -- the type is incomplete, replace it with its full view. |
| |
| procedure Check_Type is |
| begin |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| then |
| Error_Attr_P ("prefix of % attribute must be a type"); |
| |
| elsif Is_Protected_Self_Reference (P) then |
| Error_Attr_P |
| ("prefix of % attribute denotes current instance " |
| & "(RM 9.4(21/2))"); |
| |
| elsif Ekind (Entity (P)) = E_Incomplete_Type |
| and then Present (Full_View (Entity (P))) |
| then |
| P_Type := Full_View (Entity (P)); |
| Set_Entity (P, P_Type); |
| end if; |
| end Check_Type; |
| |
| --------------------- |
| -- Check_Unit_Name -- |
| --------------------- |
| |
| procedure Check_Unit_Name (Nod : Node_Id) is |
| begin |
| if Nkind (Nod) = N_Identifier then |
| return; |
| |
| elsif Nkind_In (Nod, N_Selected_Component, N_Expanded_Name) then |
| Check_Unit_Name (Prefix (Nod)); |
| |
| if Nkind (Selector_Name (Nod)) = N_Identifier then |
| return; |
| end if; |
| end if; |
| |
| Error_Attr ("argument for % attribute must be unit name", P); |
| end Check_Unit_Name; |
| |
| ---------------- |
| -- Error_Attr -- |
| ---------------- |
| |
| procedure Error_Attr is |
| begin |
| Set_Etype (N, Any_Type); |
| Set_Entity (N, Any_Type); |
| raise Bad_Attribute; |
| end Error_Attr; |
| |
| procedure Error_Attr (Msg : String; Error_Node : Node_Id) is |
| begin |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N (Msg, Error_Node); |
| Error_Attr; |
| end Error_Attr; |
| |
| ------------------ |
| -- Error_Attr_P -- |
| ------------------ |
| |
| procedure Error_Attr_P (Msg : String) is |
| begin |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_F (Msg, P); |
| Error_Attr; |
| end Error_Attr_P; |
| |
| ---------------------------- |
| -- Legal_Formal_Attribute -- |
| ---------------------------- |
| |
| procedure Legal_Formal_Attribute is |
| begin |
| Check_E0; |
| |
| if not Is_Entity_Name (P) |
| or else not Is_Type (Entity (P)) |
| then |
| Error_Attr_P ("prefix of % attribute must be generic type"); |
| |
| elsif Is_Generic_Actual_Type (Entity (P)) |
| or else In_Instance |
| or else In_Inlined_Body |
| then |
| null; |
| |
| elsif Is_Generic_Type (Entity (P)) then |
| if Is_Definite_Subtype (Entity (P)) then |
| Error_Attr_P |
| ("prefix of % attribute must be indefinite generic type"); |
| end if; |
| |
| else |
| Error_Attr_P |
| ("prefix of % attribute must be indefinite generic type"); |
| end if; |
| |
| Set_Etype (N, Standard_Boolean); |
| end Legal_Formal_Attribute; |
| |
| --------------------------------------------------------------- |
| -- Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements -- |
| --------------------------------------------------------------- |
| |
| procedure Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements is |
| begin |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| end Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements; |
| |
| ------------- |
| -- Min_Max -- |
| ------------- |
| |
| procedure Min_Max is |
| begin |
| Check_E2; |
| Check_Scalar_Type; |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| -- Check for comparison on unordered enumeration type |
| |
| if Bad_Unordered_Enumeration_Reference (N, P_Base_Type) then |
| Error_Msg_Sloc := Sloc (P_Base_Type); |
| Error_Msg_NE |
| ("comparison on unordered enumeration type& declared#?U?", |
| N, P_Base_Type); |
| end if; |
| end Min_Max; |
| |
| ------------------------ |
| -- Standard_Attribute -- |
| ------------------------ |
| |
| procedure Standard_Attribute (Val : Int) is |
| begin |
| Check_Standard_Prefix; |
| Rewrite (N, Make_Integer_Literal (Loc, Val)); |
| Analyze (N); |
| Set_Is_Static_Expression (N, True); |
| end Standard_Attribute; |
| |
| -------------------- |
| -- Uneval_Old_Msg -- |
| -------------------- |
| |
| procedure Uneval_Old_Msg is |
| Uneval_Old_Setting : Character; |
| Prag : Node_Id; |
| |
| begin |
| -- If from aspect, then Uneval_Old_Setting comes from flags in the |
| -- N_Aspect_Specification node that corresponds to the attribute. |
| |
| -- First find the pragma in which we appear (note that at this stage, |
| -- even if we appeared originally within an aspect specification, we |
| -- are now within the corresponding pragma). |
| |
| Prag := N; |
| loop |
| Prag := Parent (Prag); |
| exit when No (Prag) or else Nkind (Prag) = N_Pragma; |
| end loop; |
| |
| if Present (Prag) then |
| if Uneval_Old_Accept (Prag) then |
| Uneval_Old_Setting := 'A'; |
| elsif Uneval_Old_Warn (Prag) then |
| Uneval_Old_Setting := 'W'; |
| else |
| Uneval_Old_Setting := 'E'; |
| end if; |
| |
| -- If we did not find the pragma, that's odd, just use the setting |
| -- from Opt.Uneval_Old. Perhaps this is due to a previous error? |
| |
| else |
| Uneval_Old_Setting := Opt.Uneval_Old; |
| end if; |
| |
| -- Processing depends on the setting of Uneval_Old |
| |
| case Uneval_Old_Setting is |
| when 'E' => |
| Error_Attr_P |
| ("prefix of attribute % that is potentially " |
| & "unevaluated must denote an entity"); |
| |
| when 'W' => |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_F |
| ("??prefix of attribute % appears in potentially " |
| & "unevaluated context, exception may be raised", P); |
| |
| when 'A' => |
| null; |
| |
| when others => |
| raise Program_Error; |
| end case; |
| end Uneval_Old_Msg; |
| |
| ------------------------- |
| -- Unexpected Argument -- |
| ------------------------- |
| |
| procedure Unexpected_Argument (En : Node_Id) is |
| begin |
| Error_Attr ("unexpected argument for % attribute", En); |
| end Unexpected_Argument; |
| |
| ------------------------------------------------- |
| -- Validate_Non_Static_Attribute_Function_Call -- |
| ------------------------------------------------- |
| |
| -- This function should be moved to Sem_Dist ??? |
| |
| procedure Validate_Non_Static_Attribute_Function_Call is |
| begin |
| if In_Preelaborated_Unit |
| and then not In_Subprogram_Or_Concurrent_Unit |
| then |
| Flag_Non_Static_Expr |
| ("non-static function call in preelaborated unit!", N); |
| end if; |
| end Validate_Non_Static_Attribute_Function_Call; |
| |
| -- Start of processing for Analyze_Attribute |
| |
| begin |
| -- Immediate return if unrecognized attribute (already diagnosed by |
| -- parser, so there is nothing more that we need to do). |
| |
| if not Is_Attribute_Name (Aname) then |
| raise Bad_Attribute; |
| end if; |
| |
| Check_Restriction_No_Use_Of_Attribute (N); |
| |
| -- Deal with Ada 83 issues |
| |
| if Comes_From_Source (N) then |
| if not Attribute_83 (Attr_Id) then |
| if Ada_Version = Ada_83 and then Comes_From_Source (N) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N ("(Ada 83) attribute% is not standard??", N); |
| end if; |
| |
| if Attribute_Impl_Def (Attr_Id) then |
| Check_Restriction (No_Implementation_Attributes, N); |
| end if; |
| end if; |
| end if; |
| |
| -- Deal with Ada 2005 attributes that are implementation attributes |
| -- because they appear in a version of Ada before Ada 2005, and |
| -- similarly for Ada 2012 attributes appearing in an earlier version. |
| |
| if (Attribute_05 (Attr_Id) and then Ada_Version < Ada_2005) |
| or else |
| (Attribute_12 (Attr_Id) and then Ada_Version < Ada_2012) |
| then |
| Check_Restriction (No_Implementation_Attributes, N); |
| end if; |
| |
| -- Remote access to subprogram type access attribute reference needs |
| -- unanalyzed copy for tree transformation. The analyzed copy is used |
| -- for its semantic information (whether prefix is a remote subprogram |
| -- name), the unanalyzed copy is used to construct new subtree rooted |
| -- with N_Aggregate which represents a fat pointer aggregate. |
| |
| if Aname = Name_Access then |
| Discard_Node (Copy_Separate_Tree (N)); |
| end if; |
| |
| -- Analyze prefix and exit if error in analysis. If the prefix is an |
| -- incomplete type, use full view if available. Note that there are |
| -- some attributes for which we do not analyze the prefix, since the |
| -- prefix is not a normal name, or else needs special handling. |
| |
| if Aname /= Name_Elab_Body and then |
| Aname /= Name_Elab_Spec and then |
| Aname /= Name_Elab_Subp_Body and then |
| Aname /= Name_Enabled and then |
| Aname /= Name_Old |
| then |
| Analyze (P); |
| P_Type := Etype (P); |
| |
| if Is_Entity_Name (P) |
| and then Present (Entity (P)) |
| and then Is_Type (Entity (P)) |
| then |
| if Ekind (Entity (P)) = E_Incomplete_Type then |
| P_Type := Get_Full_View (P_Type); |
| Set_Entity (P, P_Type); |
| Set_Etype (P, P_Type); |
| |
| elsif Entity (P) = Current_Scope |
| and then Is_Record_Type (Entity (P)) |
| then |
| -- Use of current instance within the type. Verify that if the |
| -- attribute appears within a constraint, it yields an access |
| -- type, other uses are illegal. |
| |
| declare |
| Par : Node_Id; |
| |
| begin |
| Par := Parent (N); |
| while Present (Par) |
| and then Nkind (Parent (Par)) /= N_Component_Definition |
| loop |
| Par := Parent (Par); |
| end loop; |
| |
| if Present (Par) |
| and then Nkind (Par) = N_Subtype_Indication |
| then |
| if Attr_Id /= Attribute_Access |
| and then Attr_Id /= Attribute_Unchecked_Access |
| and then Attr_Id /= Attribute_Unrestricted_Access |
| then |
| Error_Msg_N |
| ("in a constraint the current instance can only " |
| & "be used with an access attribute", N); |
| end if; |
| end if; |
| end; |
| end if; |
| end if; |
| |
| if P_Type = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| |
| P_Base_Type := Base_Type (P_Type); |
| end if; |
| |
| -- Analyze expressions that may be present, exiting if an error occurs |
| |
| if No (Exprs) then |
| E1 := Empty; |
| E2 := Empty; |
| |
| else |
| E1 := First (Exprs); |
| |
| -- Skip analysis for case of Restriction_Set, we do not expect |
| -- the argument to be analyzed in this case. |
| |
| if Aname /= Name_Restriction_Set then |
| Analyze (E1); |
| |
| -- Check for missing/bad expression (result of previous error) |
| |
| if No (E1) or else Etype (E1) = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| end if; |
| |
| E2 := Next (E1); |
| |
| if Present (E2) then |
| Analyze (E2); |
| |
| if Etype (E2) = Any_Type then |
| raise Bad_Attribute; |
| end if; |
| |
| if Present (Next (E2)) then |
| Unexpected_Argument (Next (E2)); |
| end if; |
| end if; |
| end if; |
| |
| -- Cases where prefix must be resolvable by itself |
| |
| if Is_Overloaded (P) |
| and then Aname /= Name_Access |
| and then Aname /= Name_Address |
| and then Aname /= Name_Code_Address |
| and then Aname /= Name_Result |
| and then Aname /= Name_Unchecked_Access |
| then |
| -- The prefix must be resolvable by itself, without reference to the |
| -- attribute. One case that requires special handling is a prefix |
| -- that is a function name, where one interpretation may be a |
| -- parameterless call. Entry attributes are handled specially below. |
| |
| if Is_Entity_Name (P) |
| and then not Nam_In (Aname, Name_Count, Name_Caller) |
| then |
| Check_Parameterless_Call (P); |
| end if; |
| |
| if Is_Overloaded (P) then |
| |
| -- Ada 2005 (AI-345): Since protected and task types have |
| -- primitive entry wrappers, the attributes Count, and Caller |
| -- require a context check |
| |
| if Nam_In (Aname, Name_Count, Name_Caller) then |
| declare |
| Count : Natural := 0; |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (P, I, It); |
| while Present (It.Nam) loop |
| if Comes_From_Source (It.Nam) then |
| Count := Count + 1; |
| else |
| Remove_Interp (I); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| if Count > 1 then |
| Error_Attr ("ambiguous prefix for % attribute", P); |
| else |
| Set_Is_Overloaded (P, False); |
| end if; |
| end; |
| |
| else |
| Error_Attr ("ambiguous prefix for % attribute", P); |
| end if; |
| end if; |
| end if; |
| |
| -- In SPARK, attributes of private types are only allowed if the full |
| -- type declaration is visible. |
| |
| -- Note: the check for Present (Entity (P)) defends against some error |
| -- conditions where the Entity field is not set. |
| |
| if Is_Entity_Name (P) and then Present (Entity (P)) |
| and then Is_Type (Entity (P)) |
| and then Is_Private_Type (P_Type) |
| and then not In_Open_Scopes (Scope (P_Type)) |
| and then not In_Spec_Expression |
| then |
| Check_SPARK_05_Restriction ("invisible attribute of type", N); |
| end if; |
| |
| -- Remaining processing depends on attribute |
| |
| case Attr_Id is |
| |
| -- Attributes related to Ada 2012 iterators. Attribute specifications |
| -- exist for these, but they cannot be queried. |
| |
| when Attribute_Constant_Indexing |
| | Attribute_Default_Iterator |
| | Attribute_Implicit_Dereference |
| | Attribute_Iterator_Element |
| | Attribute_Iterable |
| | Attribute_Variable_Indexing |
| => |
| Error_Msg_N ("illegal attribute", N); |
| |
| -- Internal attributes used to deal with Ada 2012 delayed aspects. These |
| -- were already rejected by the parser. Thus they shouldn't appear here. |
| |
| when Internal_Attribute_Id => |
| raise Program_Error; |
| |
| ------------------ |
| -- Abort_Signal -- |
| ------------------ |
| |
| when Attribute_Abort_Signal => |
| Check_Standard_Prefix; |
| Rewrite (N, New_Occurrence_Of (Stand.Abort_Signal, Loc)); |
| Analyze (N); |
| |
| ------------ |
| -- Access -- |
| ------------ |
| |
| when Attribute_Access => |
| Analyze_Access_Attribute; |
| Check_Not_Incomplete_Type; |
| |
| ------------- |
| -- Address -- |
| ------------- |
| |
| when Attribute_Address => |
| Check_E0; |
| Address_Checks; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, RTE (RE_Address)); |
| |
| ------------------ |
| -- Address_Size -- |
| ------------------ |
| |
| when Attribute_Address_Size => |
| Standard_Attribute (System_Address_Size); |
| |
| -------------- |
| -- Adjacent -- |
| -------------- |
| |
| when Attribute_Adjacent => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| |
| --------- |
| -- Aft -- |
| --------- |
| |
| when Attribute_Aft => |
| Check_Fixed_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Alignment -- |
| --------------- |
| |
| when Attribute_Alignment => |
| |
| -- Don't we need more checking here, cf Size ??? |
| |
| Check_E0; |
| Check_Not_Incomplete_Type; |
| Check_Not_CPP_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Asm_Input -- |
| --------------- |
| |
| when Attribute_Asm_Input => |
| Check_Asm_Attribute; |
| |
| -- The back end may need to take the address of E2 |
| |
| if Is_Entity_Name (E2) then |
| Set_Address_Taken (Entity (E2)); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Asm_Input_Operand)); |
| |
| ---------------- |
| -- Asm_Output -- |
| ---------------- |
| |
| when Attribute_Asm_Output => |
| Check_Asm_Attribute; |
| |
| if Etype (E2) = Any_Type then |
| return; |
| |
| elsif Aname = Name_Asm_Output then |
| if not Is_Variable (E2) then |
| Error_Attr |
| ("second argument for Asm_Output is not variable", E2); |
| end if; |
| end if; |
| |
| Note_Possible_Modification (E2, Sure => True); |
| |
| -- The back end may need to take the address of E2 |
| |
| if Is_Entity_Name (E2) then |
| Set_Address_Taken (Entity (E2)); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Asm_Output_Operand)); |
| |
| ----------------------------- |
| -- Atomic_Always_Lock_Free -- |
| ----------------------------- |
| |
| when Attribute_Atomic_Always_Lock_Free => |
| Check_E0; |
| Check_Type; |
| Set_Etype (N, Standard_Boolean); |
| |
| ---------- |
| -- Base -- |
| ---------- |
| |
| -- Note: when the base attribute appears in the context of a subtype |
| -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by |
| -- the following circuit. |
| |
| when Attribute_Base => Base : declare |
| Typ : Entity_Id; |
| |
| begin |
| Check_E0; |
| Find_Type (P); |
| Typ := Entity (P); |
| |
| if Ada_Version >= Ada_95 |
| and then not Is_Scalar_Type (Typ) |
| and then not Is_Generic_Type (Typ) |
| then |
| Error_Attr_P ("prefix of Base attribute must be scalar type"); |
| |
| elsif Sloc (Typ) = Standard_Location |
| and then Base_Type (Typ) = Typ |
| and then Warn_On_Redundant_Constructs |
| then |
| Error_Msg_NE -- CODEFIX |
| ("?r?redundant attribute, & is its own base type", N, Typ); |
| end if; |
| |
| if Nkind (Parent (N)) /= N_Attribute_Reference then |
| Error_Msg_Name_1 := Aname; |
| Check_SPARK_05_Restriction |
| ("attribute% is only allowed as prefix of another attribute", P); |
| end if; |
| |
| Set_Etype (N, Base_Type (Entity (P))); |
| Set_Entity (N, Base_Type (Entity (P))); |
| Rewrite (N, New_Occurrence_Of (Entity (N), Loc)); |
| Analyze (N); |
| end Base; |
| |
| --------- |
| -- Bit -- |
| --------- |
| |
| when Attribute_Bit => |
| Check_E0; |
| |
| if not Is_Object_Reference (P) then |
| Error_Attr_P ("prefix for % attribute must be object"); |
| |
| -- What about the access object cases ??? |
| |
| else |
| null; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Bit_Order -- |
| --------------- |
| |
| when Attribute_Bit_Order => |
| Check_E0; |
| Check_Type; |
| |
| if not Is_Record_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be record type"); |
| end if; |
| |
| if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_High_Order_First), Loc)); |
| else |
| Rewrite (N, |
| New_Occurrence_Of (RTE (RE_Low_Order_First), Loc)); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Bit_Order)); |
| Resolve (N); |
| |
| -- Reset incorrect indication of staticness |
| |
| Set_Is_Static_Expression (N, False); |
| |
| ------------------ |
| -- Bit_Position -- |
| ------------------ |
| |
| -- Note: in generated code, we can have a Bit_Position attribute |
| -- applied to a (naked) record component (i.e. the prefix is an |
| -- identifier that references an E_Component or E_Discriminant |
| -- entity directly, and this is interpreted as expected by Gigi. |
| -- The following code will not tolerate such usage, but when the |
| -- expander creates this special case, it marks it as analyzed |
| -- immediately and sets an appropriate type. |
| |
| when Attribute_Bit_Position => |
| if Comes_From_Source (N) then |
| Check_Component; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------ |
| -- Body_Version -- |
| ------------------ |
| |
| when Attribute_Body_Version => |
| Check_E0; |
| Check_Program_Unit; |
| Set_Etype (N, RTE (RE_Version_String)); |
| |
| -------------- |
| -- Callable -- |
| -------------- |
| |
| when Attribute_Callable => |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| Check_Task_Prefix; |
| |
| ------------ |
| -- Caller -- |
| ------------ |
| |
| when Attribute_Caller => Caller : declare |
| Ent : Entity_Id; |
| S : Entity_Id; |
| |
| begin |
| Check_E0; |
| |
| if Nkind_In (P, N_Identifier, N_Expanded_Name) then |
| Ent := Entity (P); |
| |
| if not Is_Entry (Ent) then |
| Error_Attr ("invalid entry name", N); |
| end if; |
| |
| else |
| Error_Attr ("invalid entry name", N); |
| return; |
| end if; |
| |
| for J in reverse 0 .. Scope_Stack.Last loop |
| S := Scope_Stack.Table (J).Entity; |
| |
| if S = Scope (Ent) then |
| Error_Attr ("Caller must appear in matching accept or body", N); |
| elsif S = Ent then |
| exit; |
| end if; |
| end loop; |
| |
| Set_Etype (N, RTE (RO_AT_Task_Id)); |
| end Caller; |
| |
| ------------- |
| -- Ceiling -- |
| ------------- |
| |
| when Attribute_Ceiling => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ----------- |
| -- Class -- |
| ----------- |
| |
| when Attribute_Class => |
| Check_Restriction (No_Dispatch, N); |
| Check_E0; |
| Find_Type (N); |
| |
| -- Applying Class to untagged incomplete type is obsolescent in Ada |
| -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since |
| -- this flag gets set by Find_Type in this situation. |
| |
| if Restriction_Check_Required (No_Obsolescent_Features) |
| and then Ada_Version >= Ada_2005 |
| and then Ekind (P_Type) = E_Incomplete_Type |
| then |
| declare |
| DN : constant Node_Id := Declaration_Node (P_Type); |
| begin |
| if Nkind (DN) = N_Incomplete_Type_Declaration |
| and then not Tagged_Present (DN) |
| then |
| Check_Restriction (No_Obsolescent_Features, P); |
| end if; |
| end; |
| end if; |
| |
| ------------------ |
| -- Code_Address -- |
| ------------------ |
| |
| when Attribute_Code_Address => |
| Check_E0; |
| |
| if Nkind (P) = N_Attribute_Reference |
| and then Nam_In (Attribute_Name (P), Name_Elab_Body, Name_Elab_Spec) |
| then |
| null; |
| |
| elsif not Is_Entity_Name (P) |
| or else (Ekind (Entity (P)) /= E_Function |
| and then |
| Ekind (Entity (P)) /= E_Procedure) |
| then |
| Error_Attr ("invalid prefix for % attribute", P); |
| Set_Address_Taken (Entity (P)); |
| |
| -- Issue an error if the prefix denotes an eliminated subprogram |
| |
| else |
| Check_For_Eliminated_Subprogram (P, Entity (P)); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Address)); |
| |
| ---------------------- |
| -- Compiler_Version -- |
| ---------------------- |
| |
| when Attribute_Compiler_Version => |
| Check_E0; |
| Check_Standard_Prefix; |
| Rewrite (N, Make_String_Literal (Loc, "GNAT " & Gnat_Version_String)); |
| Analyze_And_Resolve (N, Standard_String); |
| Set_Is_Static_Expression (N, True); |
| |
| -------------------- |
| -- Component_Size -- |
| -------------------- |
| |
| when Attribute_Component_Size => |
| Check_E0; |
| Set_Etype (N, Universal_Integer); |
| |
| -- Note: unlike other array attributes, unconstrained arrays are OK |
| |
| if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then |
| null; |
| else |
| Check_Array_Type; |
| end if; |
| |
| ------------- |
| -- Compose -- |
| ------------- |
| |
| when Attribute_Compose => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, Any_Integer); |
| |
| ----------------- |
| -- Constrained -- |
| ----------------- |
| |
| when Attribute_Constrained => |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| -- Case from RM J.4(2) of constrained applied to private type |
| |
| if Is_Entity_Name (P) and then Is_Type (Entity (P)) then |
| Check_Restriction (No_Obsolescent_Features, P); |
| |
| if Warn_On_Obsolescent_Feature then |
| Error_Msg_N |
| ("constrained for private type is an obsolescent feature " |
| & "(RM J.4)?j?", N); |
| end if; |
| |
| -- If we are within an instance, the attribute must be legal |
| -- because it was valid in the generic unit. Ditto if this is |
| -- an inlining of a function declared in an instance. |
| |
| if In_Instance or else In_Inlined_Body then |
| return; |
| |
| -- For sure OK if we have a real private type itself, but must |
| -- be completed, cannot apply Constrained to incomplete type. |
| |
| elsif Is_Private_Type (Entity (P)) then |
| |
| -- Note: this is one of the Annex J features that does not |
| -- generate a warning from -gnatwj, since in fact it seems |
| -- very useful, and is used in the GNAT runtime. |
| |
| Check_Not_Incomplete_Type; |
| return; |
| end if; |
| |
| -- Normal (non-obsolescent case) of application to object of |
| -- a discriminated type. |
| |
| else |
| Check_Object_Reference (P); |
| |
| -- If N does not come from source, then we allow the |
| -- the attribute prefix to be of a private type whose |
| -- full type has discriminants. This occurs in cases |
| -- involving expanded calls to stream attributes. |
| |
| if not Comes_From_Source (N) then |
| P_Type := Underlying_Type (P_Type); |
| end if; |
| |
| -- Must have discriminants or be an access type designating a type |
| -- with discriminants. If it is a class-wide type it has unknown |
| -- discriminants. |
| |
| if Has_Discriminants (P_Type) |
| or else Has_Unknown_Discriminants (P_Type) |
| or else |
| (Is_Access_Type (P_Type) |
| and then Has_Discriminants (Designated_Type (P_Type))) |
| then |
| return; |
| |
| -- The rule given in 3.7.2 is part of static semantics, but the |
| -- intent is clearly that it be treated as a legality rule, and |
| -- rechecked in the visible part of an instance. Nevertheless |
| -- the intent also seems to be it should legally apply to the |
| -- actual of a formal with unknown discriminants, regardless of |
| -- whether the actual has discriminants, in which case the value |
| -- of the attribute is determined using the J.4 rules. This choice |
| -- seems the most useful, and is compatible with existing tests. |
| |
| elsif In_Instance then |
| return; |
| |
| -- Also allow an object of a generic type if extensions allowed |
| -- and allow this for any type at all. (this may be obsolete ???) |
| |
| elsif (Is_Generic_Type (P_Type) |
| or else Is_Generic_Actual_Type (P_Type)) |
| and then Extensions_Allowed |
| then |
| return; |
| end if; |
| end if; |
| |
| -- Fall through if bad prefix |
| |
| Error_Attr_P |
| ("prefix of % attribute must be object of discriminated type"); |
| |
| --------------- |
| -- Copy_Sign -- |
| --------------- |
| |
| when Attribute_Copy_Sign => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| |
| ----------- |
| -- Count -- |
| ----------- |
| |
| when Attribute_Count => Count : declare |
| Ent : Entity_Id; |
| S : Entity_Id; |
| Tsk : Entity_Id; |
| |
| begin |
| Check_E0; |
| |
| if Nkind_In (P, N_Identifier, N_Expanded_Name) then |
| Ent := Entity (P); |
| |
| if Ekind (Ent) /= E_Entry then |
| Error_Attr ("invalid entry name", N); |
| end if; |
| |
| elsif Nkind (P) = N_Indexed_Component then |
| if not Is_Entity_Name (Prefix (P)) |
| or else No (Entity (Prefix (P))) |
| or else Ekind (Entity (Prefix (P))) /= E_Entry_Family |
| then |
| if Nkind (Prefix (P)) = N_Selected_Component |
| and then Present (Entity (Selector_Name (Prefix (P)))) |
| and then Ekind (Entity (Selector_Name (Prefix (P)))) = |
| E_Entry_Family |
| then |
| Error_Attr |
| ("attribute % must apply to entry of current task", P); |
| |
| else |
| Error_Attr ("invalid entry family name", P); |
| end if; |
| return; |
| |
| else |
| Ent := Entity (Prefix (P)); |
| end if; |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Present (Entity (Selector_Name (P))) |
| and then Ekind (Entity (Selector_Name (P))) = E_Entry |
| then |
| Error_Attr |
| ("attribute % must apply to entry of current task", P); |
| |
| else |
| Error_Attr ("invalid entry name", N); |
| return; |
| end if; |
| |
| for J in reverse 0 .. Scope_Stack.Last loop |
| S := Scope_Stack.Table (J).Entity; |
| |
| if S = Scope (Ent) then |
| if Nkind (P) = N_Expanded_Name then |
| Tsk := Entity (Prefix (P)); |
| |
| -- The prefix denotes either the task type, or else a |
| -- single task whose task type is being analyzed. |
| |
| if (Is_Type (Tsk) and then Tsk = S) |
| or else (not Is_Type (Tsk) |
| and then Etype (Tsk) = S |
| and then not (Comes_From_Source (S))) |
| then |
| null; |
| else |
| Error_Attr |
| ("Attribute % must apply to entry of current task", N); |
| end if; |
| end if; |
| |
| exit; |
| |
| elsif Ekind (Scope (Ent)) in Task_Kind |
| and then not Ekind_In (S, E_Block, |
| E_Entry, |
| E_Entry_Family, |
| E_Loop) |
| then |
| Error_Attr ("Attribute % cannot appear in inner unit", N); |
| |
| elsif Ekind (Scope (Ent)) = E_Protected_Type |
| and then not Has_Completion (Scope (Ent)) |
| then |
| Error_Attr ("attribute % can only be used inside body", N); |
| end if; |
| end loop; |
| |
| if Is_Overloaded (P) then |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (P, Index, It); |
| while Present (It.Nam) loop |
| if It.Nam = Ent then |
| null; |
| |
| -- Ada 2005 (AI-345): Do not consider primitive entry |
| -- wrappers generated for task or protected types. |
| |
| elsif Ada_Version >= Ada_2005 |
| and then not Comes_From_Source (It.Nam) |
| then |
| null; |
| |
| else |
| Error_Attr ("ambiguous entry name", N); |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| end Count; |
| |
| ----------------------- |
| -- Default_Bit_Order -- |
| ----------------------- |
| |
| when Attribute_Default_Bit_Order => Default_Bit_Order : declare |
| Target_Default_Bit_Order : System.Bit_Order; |
| |
| begin |
| Check_Standard_Prefix; |
| |
| if Bytes_Big_Endian then |
| Target_Default_Bit_Order := System.High_Order_First; |
| else |
| Target_Default_Bit_Order := System.Low_Order_First; |
| end if; |
| |
| Rewrite (N, |
| Make_Integer_Literal (Loc, |
| UI_From_Int (System.Bit_Order'Pos (Target_Default_Bit_Order)))); |
| |
| Set_Etype (N, Universal_Integer); |
| Set_Is_Static_Expression (N); |
| end Default_Bit_Order; |
| |
| ---------------------------------- |
| -- Default_Scalar_Storage_Order -- |
| ---------------------------------- |
| |
| when Attribute_Default_Scalar_Storage_Order => Default_SSO : declare |
| RE_Default_SSO : RE_Id; |
| |
| begin |
| Check_Standard_Prefix; |
| |
| case Opt.Default_SSO is |
| when ' ' => |
| if Bytes_Big_Endian then |
| RE_Default_SSO := RE_High_Order_First; |
| else |
| RE_Default_SSO := RE_Low_Order_First; |
| end if; |
| |
| when 'H' => |
| RE_Default_SSO := RE_High_Order_First; |
| |
| when 'L' => |
| RE_Default_SSO := RE_Low_Order_First; |
| |
| when others => |
| raise Program_Error; |
| end case; |
| |
| Rewrite (N, New_Occurrence_Of (RTE (RE_Default_SSO), Loc)); |
| end Default_SSO; |
| |
| -------------- |
| -- Definite -- |
| -------------- |
| |
| when Attribute_Definite => |
| Legal_Formal_Attribute; |
| |
| ----------- |
| -- Delta -- |
| ----------- |
| |
| when Attribute_Delta => |
| Check_Fixed_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ------------ |
| -- Denorm -- |
| ------------ |
| |
| when Attribute_Denorm => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ----------- |
| -- Deref -- |
| ----------- |
| |
| when Attribute_Deref => |
| Check_Type; |
| Check_E1; |
| Resolve (E1, RTE (RE_Address)); |
| Set_Etype (N, P_Type); |
| |
| --------------------- |
| -- Descriptor_Size -- |
| --------------------- |
| |
| when Attribute_Descriptor_Size => |
| Check_E0; |
| |
| if not Is_Entity_Name (P) or else not Is_Type (Entity (P)) then |
| Error_Attr_P ("prefix of attribute % must denote a type"); |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| ------------ |
| -- Digits -- |
| ------------ |
| |
| when Attribute_Digits => |
| Check_E0; |
| Check_Type; |
| |
| if not Is_Floating_Point_Type (P_Type) |
| and then not Is_Decimal_Fixed_Point_Type (P_Type) |
| then |
| Error_Attr_P |
| ("prefix of % attribute must be float or decimal type"); |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Elab_Body -- |
| --------------- |
| |
| -- Also handles processing for Elab_Spec and Elab_Subp_Body |
| |
| when Attribute_Elab_Body |
| | Attribute_Elab_Spec |
| | Attribute_Elab_Subp_Body |
| => |
| Check_E0; |
| Check_Unit_Name (P); |
| Set_Etype (N, Standard_Void_Type); |
| |
| -- We have to manually call the expander in this case to get |
| -- the necessary expansion (normally attributes that return |
| -- entities are not expanded). |
| |
| Expand (N); |
| |
| --------------- |
| -- Elab_Spec -- |
| --------------- |
| |
| -- Shares processing with Elab_Body |
| |
| ---------------- |
| -- Elaborated -- |
| ---------------- |
| |
| when Attribute_Elaborated => |
| Check_E0; |
| Check_Unit_Name (P); |
| Set_Etype (N, Standard_Boolean); |
| |
| ---------- |
| -- Emax -- |
| ---------- |
| |
| when Attribute_Emax => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------- |
| -- Enabled -- |
| ------------- |
| |
| when Attribute_Enabled => |
| Check_Either_E0_Or_E1; |
| |
| if Present (E1) then |
| if not Is_Entity_Name (E1) or else No (Entity (E1)) then |
| Error_Msg_N ("entity name expected for Enabled attribute", E1); |
| E1 := Empty; |
| end if; |
| end if; |
| |
| if Nkind (P) /= N_Identifier then |
| Error_Msg_N ("identifier expected (check name)", P); |
| elsif Get_Check_Id (Chars (P)) = No_Check_Id then |
| Error_Msg_N ("& is not a recognized check name", P); |
| end if; |
| |
| Set_Etype (N, Standard_Boolean); |
| |
| -------------- |
| -- Enum_Rep -- |
| -------------- |
| |
| when Attribute_Enum_Rep => |
| |
| -- T'Enum_Rep (X) case |
| |
| if Present (E1) then |
| Check_E1; |
| Check_Discrete_Type; |
| Resolve (E1, P_Base_Type); |
| |
| -- X'Enum_Rep case. X must be an object or enumeration literal, and |
| -- it must be of a discrete type. |
| |
| elsif not |
| ((Is_Object_Reference (P) |
| or else |
| (Is_Entity_Name (P) |
| and then Ekind (Entity (P)) = E_Enumeration_Literal)) |
| and then Is_Discrete_Type (Etype (P))) |
| then |
| Error_Attr_P ("prefix of % attribute must be discrete object"); |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Enum_Val -- |
| -------------- |
| |
| when Attribute_Enum_Val => |
| Check_E1; |
| Check_Type; |
| |
| if not Is_Enumeration_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be enumeration type"); |
| end if; |
| |
| -- If the enumeration type has a standard representation, the effect |
| -- is the same as 'Val, so rewrite the attribute as a 'Val. |
| |
| if not Has_Non_Standard_Rep (P_Base_Type) then |
| Rewrite (N, |
| Make_Attribute_Reference (Loc, |
| Prefix => Relocate_Node (Prefix (N)), |
| Attribute_Name => Name_Val, |
| Expressions => New_List (Relocate_Node (E1)))); |
| Analyze_And_Resolve (N, P_Base_Type); |
| |
| -- Non-standard representation case (enumeration with holes) |
| |
| else |
| Check_Enum_Image; |
| Resolve (E1, Any_Integer); |
| Set_Etype (N, P_Base_Type); |
| end if; |
| |
| ------------- |
| -- Epsilon -- |
| ------------- |
| |
| when Attribute_Epsilon => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| -------------- |
| -- Exponent -- |
| -------------- |
| |
| when Attribute_Exponent => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, Universal_Integer); |
| Resolve (E1, P_Base_Type); |
| |
| ------------------ |
| -- External_Tag -- |
| ------------------ |
| |
| when Attribute_External_Tag => |
| Check_E0; |
| Check_Type; |
| |
| Set_Etype (N, Standard_String); |
| |
| if not Is_Tagged_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be tagged"); |
| end if; |
| |
| --------------- |
| -- Fast_Math -- |
| --------------- |
| |
| when Attribute_Fast_Math => |
| Check_Standard_Prefix; |
| Rewrite (N, New_Occurrence_Of (Boolean_Literals (Fast_Math), Loc)); |
| |
| ----------------------- |
| -- Finalization_Size -- |
| ----------------------- |
| |
| when Attribute_Finalization_Size => |
| Check_E0; |
| |
| -- The prefix denotes an object |
| |
| if Is_Object_Reference (P) then |
| Check_Object_Reference (P); |
| |
| -- The prefix denotes a type |
| |
| elsif Is_Entity_Name (P) and then Is_Type (Entity (P)) then |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| |
| -- Attribute 'Finalization_Size is not defined for class-wide |
| -- types because it is not possible to know statically whether |
| -- a definite type will have controlled components or not. |
| |
| if Is_Class_Wide_Type (Etype (P)) then |
| Error_Attr_P |
| ("prefix of % attribute cannot denote a class-wide type"); |
| end if; |
| |
| -- The prefix denotes an illegal construct |
| |
| else |
| Error_Attr_P |
| ("prefix of % attribute must be a definite type or an object"); |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| ----------- |
| -- First -- |
| ----------- |
| |
| when Attribute_First => |
| Check_Array_Or_Scalar_Type; |
| Bad_Attribute_For_Predicate; |
| |
| --------------- |
| -- First_Bit -- |
| --------------- |
| |
| when Attribute_First_Bit => |
| Check_Component; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------------- |
| -- First_Valid -- |
| ----------------- |
| |
| when Attribute_First_Valid => |
| Check_First_Last_Valid; |
| Set_Etype (N, P_Type); |
| |
| ----------------- |
| -- Fixed_Value -- |
| ----------------- |
| |
| when Attribute_Fixed_Value => |
| Check_E1; |
| Check_Fixed_Point_Type; |
| Resolve (E1, Any_Integer); |
| Set_Etype (N, P_Base_Type); |
| |
| ----------- |
| -- Floor -- |
| ----------- |
| |
| when Attribute_Floor => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ---------- |
| -- Fore -- |
| ---------- |
| |
| when Attribute_Fore => |
| Check_Fixed_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Fraction -- |
| -------------- |
| |
| when Attribute_Fraction => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| -------------- |
| -- From_Any -- |
| -------------- |
| |
| when Attribute_From_Any => |
| Check_E1; |
| Check_PolyORB_Attribute; |
| Set_Etype (N, P_Base_Type); |
| |
| ----------------------- |
| -- Has_Access_Values -- |
| ----------------------- |
| |
| when Attribute_Has_Access_Values => |
| Check_Type; |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ---------------------- |
| -- Has_Same_Storage -- |
| ---------------------- |
| |
| when Attribute_Has_Same_Storage => |
| Check_E1; |
| |
| -- The arguments must be objects of any type |
| |
| Analyze_And_Resolve (P); |
| Analyze_And_Resolve (E1); |
| Check_Object_Reference (P); |
| Check_Object_Reference (E1); |
| Set_Etype (N, Standard_Boolean); |
| |
| ----------------------- |
| -- Has_Tagged_Values -- |
| ----------------------- |
| |
| when Attribute_Has_Tagged_Values => |
| Check_Type; |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ----------------------- |
| -- Has_Discriminants -- |
| ----------------------- |
| |
| when Attribute_Has_Discriminants => |
| Legal_Formal_Attribute; |
| |
| -------------- |
| -- Identity -- |
| -------------- |
| |
| when Attribute_Identity => |
| Check_E0; |
| Analyze (P); |
| |
| if Etype (P) = Standard_Exception_Type then |
| Set_Etype (N, RTE (RE_Exception_Id)); |
| |
| -- Ada 2005 (AI-345): Attribute 'Identity may be applied to task |
| -- interface class-wide types. |
| |
| elsif Is_Task_Type (Etype (P)) |
| or else (Is_Access_Type (Etype (P)) |
| and then Is_Task_Type (Designated_Type (Etype (P)))) |
| or else (Ada_Version >= Ada_2005 |
| and then Ekind (Etype (P)) = E_Class_Wide_Type |
| and then Is_Interface (Etype (P)) |
| and then Is_Task_Interface (Etype (P))) |
| then |
| Resolve (P); |
| Set_Etype (N, RTE (RO_AT_Task_Id)); |
| |
| else |
| if Ada_Version >= Ada_2005 then |
| Error_Attr_P |
| ("prefix of % attribute must be an exception, a task or a " |
| & "task interface class-wide object"); |
| else |
| Error_Attr_P |
| ("prefix of % attribute must be a task or an exception"); |
| end if; |
| end if; |
| |
| ----------- |
| -- Image -- |
| ----------- |
| |
| when Attribute_Image => |
| if Is_Real_Type (P_Type) then |
| if Ada_Version = Ada_83 and then Comes_From_Source (N) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N |
| ("(Ada 83) % attribute not allowed for real types", N); |
| end if; |
| end if; |
| |
| Analyze_Image_Attribute (Standard_String); |
| |
| --------- |
| -- Img -- |
| --------- |
| |
| when Attribute_Img => |
| Analyze_Image_Attribute (Standard_String); |
| |
| ----------- |
| -- Input -- |
| ----------- |
| |
| when Attribute_Input => |
| Check_E1; |
| Check_Stream_Attribute (TSS_Stream_Input); |
| Set_Etype (N, P_Base_Type); |
| |
| ------------------- |
| -- Integer_Value -- |
| ------------------- |
| |
| when Attribute_Integer_Value => |
| Check_E1; |
| Check_Integer_Type; |
| Resolve (E1, Any_Fixed); |
| |
| -- Signal an error if argument type is not a specific fixed-point |
| -- subtype. An error has been signalled already if the argument |
| -- was not of a fixed-point type. |
| |
| if Etype (E1) = Any_Fixed and then not Error_Posted (E1) then |
| Error_Attr ("argument of % must be of a fixed-point type", E1); |
| end if; |
| |
| Set_Etype (N, P_Base_Type); |
| |
| ------------------- |
| -- Invalid_Value -- |
| ------------------- |
| |
| when Attribute_Invalid_Value => |
| Check_E0; |
| Check_Scalar_Type; |
| Set_Etype (N, P_Base_Type); |
| Invalid_Value_Used := True; |
| |
| ----------- |
| -- Large -- |
| ----------- |
| |
| when Attribute_Large => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| ---------- |
| -- Last -- |
| ---------- |
| |
| when Attribute_Last => |
| Check_Array_Or_Scalar_Type; |
| Bad_Attribute_For_Predicate; |
| |
| -------------- |
| -- Last_Bit -- |
| -------------- |
| |
| when Attribute_Last_Bit => |
| Check_Component; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------- |
| -- Last_Valid -- |
| ---------------- |
| |
| when Attribute_Last_Valid => |
| Check_First_Last_Valid; |
| Set_Etype (N, P_Type); |
| |
| ------------------ |
| -- Leading_Part -- |
| ------------------ |
| |
| when Attribute_Leading_Part => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, Any_Integer); |
| |
| ------------ |
| -- Length -- |
| ------------ |
| |
| when Attribute_Length => |
| Check_Array_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------- |
| -- Library_Level -- |
| ------------------- |
| |
| when Attribute_Library_Level => |
| Check_E0; |
| |
| if not Is_Entity_Name (P) then |
| Error_Attr_P ("prefix of % attribute must be an entity name"); |
| end if; |
| |
| if not Inside_A_Generic then |
| Set_Boolean_Result (N, |
| Is_Library_Level_Entity (Entity (P))); |
| end if; |
| |
| Set_Etype (N, Standard_Boolean); |
| |
| --------------- |
| -- Lock_Free -- |
| --------------- |
| |
| when Attribute_Lock_Free => |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| if not Is_Protected_Type (P_Type) then |
| Error_Attr_P |
| ("prefix of % attribute must be a protected object"); |
| end if; |
| |
| ---------------- |
| -- Loop_Entry -- |
| ---------------- |
| |
| when Attribute_Loop_Entry => Loop_Entry : declare |
| procedure Check_References_In_Prefix (Loop_Id : Entity_Id); |
| -- Inspect the prefix for any uses of entities declared within the |
| -- related loop. Loop_Id denotes the loop identifier. |
| |
| -------------------------------- |
| -- Check_References_In_Prefix -- |
| -------------------------------- |
| |
| procedure Check_References_In_Prefix (Loop_Id : Entity_Id) is |
| Loop_Decl : constant Node_Id := Label_Construct (Parent (Loop_Id)); |
| |
| function Check_Reference (Nod : Node_Id) return Traverse_Result; |
| -- Determine whether a reference mentions an entity declared |
| -- within the related loop. |
| |
| function Declared_Within (Nod : Node_Id) return Boolean; |
| -- Determine whether Nod appears in the subtree of Loop_Decl |
| |
| --------------------- |
| -- Check_Reference -- |
| --------------------- |
| |
| function Check_Reference (Nod : Node_Id) return Traverse_Result is |
| begin |
| if Nkind (Nod) = N_Identifier |
| and then Present (Entity (Nod)) |
| and then Declared_Within (Declaration_Node (Entity (Nod))) |
| then |
| Error_Attr |
| ("prefix of attribute % cannot reference local entities", |
| Nod); |
| return Abandon; |
| else |
| return OK; |
| end if; |
| end Check_Reference; |
| |
| procedure Check_References is new Traverse_Proc (Check_Reference); |
| |
| --------------------- |
| -- Declared_Within -- |
| --------------------- |
| |
| function Declared_Within (Nod : Node_Id) return Boolean is |
| Stmt : Node_Id; |
| |
| begin |
| Stmt := Nod; |
| while Present (Stmt) loop |
| if Stmt = Loop_Decl then |
| return True; |
| |
| -- Prevent the search from going too far |
| |
| elsif Is_Body_Or_Package_Declaration (Stmt) then |
| exit; |
| end if; |
| |
| Stmt := Parent (Stmt); |
| end loop; |
| |
| return False; |
| end Declared_Within; |
| |
| -- Start of processing for Check_Prefix_For_Local_References |
| |
| begin |
| Check_References (P); |
| end Check_References_In_Prefix; |
| |
| -- Local variables |
| |
| Context : constant Node_Id := Parent (N); |
| Attr : Node_Id; |
| Encl_Loop : Node_Id := Empty; |
| Encl_Prag : Node_Id := Empty; |
| Loop_Id : Entity_Id := Empty; |
| Scop : Entity_Id; |
| Stmt : Node_Id; |
| |
| -- Start of processing for Loop_Entry |
| |
| begin |
| Attr := N; |
| |
| -- Set the type of the attribute now to ensure the successful |
| -- continuation of analysis even if the attribute is misplaced. |
| |
| Set_Etype (Attr, P_Type); |
| |
| -- Attribute 'Loop_Entry may appear in several flavors: |
| |
| -- * Prefix'Loop_Entry - in this form, the attribute applies to the |
| -- nearest enclosing loop. |
| |
| -- * Prefix'Loop_Entry (Expr) - depending on what Expr denotes, the |
| -- attribute may be related to a loop denoted by label Expr or |
| -- the prefix may denote an array object and Expr may act as an |
| -- indexed component. |
| |
| -- * Prefix'Loop_Entry (Expr1, ..., ExprN) - the attribute applies |
| -- to the nearest enclosing loop, all expressions are part of |
| -- an indexed component. |
| |
| -- * Prefix'Loop_Entry (Expr) (...) (...) - depending on what Expr |
| -- denotes, the attribute may be related to a loop denoted by |
| -- label Expr or the prefix may denote a multidimensional array |
| -- array object and Expr along with the rest of the expressions |
| -- may act as indexed components. |
| |
| -- Regardless of variations, the attribute reference does not have an |
| -- expression list. Instead, all available expressions are stored as |
| -- indexed components. |
| |
| -- When the attribute is part of an indexed component, find the first |
| -- expression as it will determine the semantics of 'Loop_Entry. |
| |
| -- If the attribute is itself an index in an indexed component, i.e. |
| -- a member of a list, the context itself is not relevant (the code |
| -- below would lead to an infinite loop) and the attribute applies |
| -- to the enclosing loop. |
| |
| if Nkind (Context) = N_Indexed_Component |
| and then not Is_List_Member (N) |
| then |
| E1 := First (Expressions (Context)); |
| E2 := Next (E1); |
| |
| -- The attribute reference appears in the following form: |
| |
| -- Prefix'Loop_Entry (Exp1, Expr2, ..., ExprN) [(...)] |
| |
| -- In this case, the loop name is omitted and no rewriting is |
| -- required. |
| |
| if Present (E2) then |
| null; |
| |
| -- The form of the attribute is: |
| |
| -- Prefix'Loop_Entry (Expr) [(...)] |
| |
| -- If Expr denotes a loop entry, the whole attribute and indexed |
| -- component will have to be rewritten to reflect this relation. |
| |
| else |
| pragma Assert (Present (E1)); |
| |
| -- Do not expand the expression as it may have side effects. |
| -- Simply preanalyze to determine whether it is a loop name or |
| -- something else. |
| |
| Preanalyze_And_Resolve (E1); |
| |
| if Is_Entity_Name (E1) |
| and then Present (Entity (E1)) |
| and then Ekind (Entity (E1)) = E_Loop |
| then |
| Loop_Id := Entity (E1); |
| |
| -- Transform the attribute and enclosing indexed component |
| |
| Set_Expressions (N, Expressions (Context)); |
| Rewrite (Context, N); |
| Set_Etype (Context, P_Type); |
| |
| Attr := Context; |
| end if; |
| end if; |
| end if; |
| |
| -- The prefix must denote an object |
| |
| if not Is_Object_Reference (P) then |
| Error_Attr_P ("prefix of attribute % must denote an object"); |
| end if; |
| |
| -- The prefix cannot be of a limited type because the expansion of |
| -- Loop_Entry must create a constant initialized by the evaluated |
| -- prefix. |
| |
| if Is_Limited_View (Etype (P)) then |
| Error_Attr_P ("prefix of attribute % cannot be limited"); |
| end if; |
| |
| -- Climb the parent chain to verify the location of the attribute and |
| -- find the enclosing loop. |
| |
| Stmt := Attr; |
| while Present (Stmt) loop |
| |
| -- Locate the corresponding enclosing pragma. Note that in the |
| -- case of Assert[And_Cut] and Assume, we have already checked |
| -- that the pragma appears in an appropriate loop location. |
| |
| if Nkind (Original_Node (Stmt)) = N_Pragma |
| and then Nam_In (Pragma_Name_Unmapped (Original_Node (Stmt)), |
| Name_Loop_Invariant, |
| Name_Loop_Variant, |
| Name_Assert, |
| Name_Assert_And_Cut, |
| Name_Assume) |
| then |
| Encl_Prag := Original_Node (Stmt); |
| |
| -- Locate the enclosing loop (if any). Note that Ada 2012 array |
| -- iteration may be expanded into several nested loops, we are |
| -- interested in the outermost one which has the loop identifier, |
| -- and comes from source. |
| |
| elsif Nkind (Stmt) = N_Loop_Statement |
| and then Present (Identifier (Stmt)) |
| and then Comes_From_Source (Original_Node (Stmt)) |
| and then Nkind (Original_Node (Stmt)) = N_Loop_Statement |
| then |
| Encl_Loop := Stmt; |
| |
| -- The original attribute reference may lack a loop name. Use |
| -- the name of the enclosing loop because it is the related |
| -- loop. |
| |
| if No (Loop_Id) then |
| Loop_Id := Entity (Identifier (Encl_Loop)); |
| end if; |
| |
| exit; |
| |
| -- Prevent the search from going too far |
| |
| elsif Is_Body_Or_Package_Declaration (Stmt) then |
| exit; |
| end if; |
| |
| Stmt := Parent (Stmt); |
| end loop; |
| |
| -- Loop_Entry must appear within a Loop_Assertion pragma (Assert, |
| -- Assert_And_Cut, Assume count as loop assertion pragmas for this |
| -- purpose if they appear in an appropriate location in a loop, |
| -- which was already checked by the top level pragma circuit). |
| |
| -- Loop_Entry also denotes a value and as such can appear within an |
| -- expression that is an argument for another loop aspect. In that |
| -- case it will have been expanded into the corresponding assignment. |
| |
| if Expander_Active |
| and then Nkind (Parent (N)) = N_Assignment_Statement |
| and then not Comes_From_Source (Parent (N)) |
| then |
| null; |
| |
| elsif No (Encl_Prag) then |
| Error_Attr ("attribute% must appear within appropriate pragma", N); |
| end if; |
| |
| -- A Loop_Entry that applies to a given loop statement must not |
| -- appear within a body of accept statement, if this construct is |
| -- itself enclosed by the given loop statement. |
| |
| for Index in reverse 0 .. Scope_Stack.Last loop |
| Scop := Scope_Stack.Table (Index).Entity; |
| |
| if Ekind (Scop) = E_Loop and then Scop = Loop_Id then |
| exit; |
| elsif Ekind_In (Scop, E_Block, E_Loop, E_Return_Statement) then |
| null; |
| else |
| Error_Attr |
| ("attribute % cannot appear in body or accept statement", N); |
| exit; |
| end if; |
| end loop; |
| |
| -- The prefix cannot mention entities declared within the related |
| -- loop because they will not be visible once the prefix is moved |
| -- outside the loop. |
| |
| Check_References_In_Prefix (Loop_Id); |
| |
| -- The prefix must denote a static entity if the pragma does not |
| -- apply to the innermost enclosing loop statement, or if it appears |
| -- within a potentially unevaluated epxression. |
| |
| if Is_Entity_Name (P) |
| or else Nkind (Parent (P)) = N_Object_Renaming_Declaration |
| or else Statically_Denotes_Object (P) |
| then |
| null; |
| |
| elsif Present (Encl_Loop) |
| and then Entity (Identifier (Encl_Loop)) /= Loop_Id |
| then |
| Error_Attr_P |
| ("prefix of attribute % that applies to outer loop must denote " |
| & "an entity"); |
| |
| elsif Is_Potentially_Unevaluated (P) then |
| Uneval_Old_Msg; |
| end if; |
| |
| -- Replace the Loop_Entry attribute reference by its prefix if the |
| -- related pragma is ignored. This transformation is OK with respect |
| -- to typing because Loop_Entry's type is that of its prefix. This |
| -- early transformation also avoids the generation of a useless loop |
| -- entry constant. |
| |
| if Present (Encl_Prag) and then Is_Ignored (Encl_Prag) then |
| Rewrite (N, Relocate_Node (P)); |
| Preanalyze_And_Resolve (N); |
| |
| else |
| Preanalyze_And_Resolve (P); |
| end if; |
| end Loop_Entry; |
| |
| ------------- |
| -- Machine -- |
| ------------- |
| |
| when Attribute_Machine => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ------------------ |
| -- Machine_Emax -- |
| ------------------ |
| |
| when Attribute_Machine_Emax => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------ |
| -- Machine_Emin -- |
| ------------------ |
| |
| when Attribute_Machine_Emin => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------------- |
| -- Machine_Mantissa -- |
| ---------------------- |
| |
| when Attribute_Machine_Mantissa => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------------------- |
| -- Machine_Overflows -- |
| ----------------------- |
| |
| when Attribute_Machine_Overflows => |
| Check_Real_Type; |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------------- |
| -- Machine_Radix -- |
| ------------------- |
| |
| when Attribute_Machine_Radix => |
| Check_Real_Type; |
| Check_E0; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------------- |
| -- Machine_Rounding -- |
| ---------------------- |
| |
| when Attribute_Machine_Rounding => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| -------------------- |
| -- Machine_Rounds -- |
| -------------------- |
| |
| when Attribute_Machine_Rounds => |
| Check_Real_Type; |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------------ |
| -- Machine_Size -- |
| ------------------ |
| |
| when Attribute_Machine_Size => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Mantissa -- |
| -------------- |
| |
| when Attribute_Mantissa => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| --------- |
| -- Max -- |
| --------- |
| |
| when Attribute_Max => |
| Min_Max; |
| |
| ---------------------------------- |
| -- Max_Alignment_For_Allocation -- |
| ---------------------------------- |
| |
| when Attribute_Max_Size_In_Storage_Elements => |
| Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements; |
| |
| ---------------------------------- |
| -- Max_Size_In_Storage_Elements -- |
| ---------------------------------- |
| |
| when Attribute_Max_Alignment_For_Allocation => |
| Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements; |
| |
| ----------------------- |
| -- Maximum_Alignment -- |
| ----------------------- |
| |
| when Attribute_Maximum_Alignment => |
| Standard_Attribute (Ttypes.Maximum_Alignment); |
| |
| -------------------- |
| -- Mechanism_Code -- |
| -------------------- |
| |
| when Attribute_Mechanism_Code => |
| if not Is_Entity_Name (P) |
| or else not Is_Subprogram (Entity (P)) |
| then |
| Error_Attr_P ("prefix of % attribute must be subprogram"); |
| end if; |
| |
| Check_Either_E0_Or_E1; |
| |
| if Present (E1) then |
| Resolve (E1, Any_Integer); |
| Set_Etype (E1, Standard_Integer); |
| |
| if not Is_OK_Static_Expression (E1) then |
| Flag_Non_Static_Expr |
| ("expression for parameter number must be static!", E1); |
| Error_Attr; |
| |
| elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P)) |
| or else UI_To_Int (Intval (E1)) < 0 |
| then |
| Error_Attr ("invalid parameter number for % attribute", E1); |
| end if; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| --------- |
| -- Min -- |
| --------- |
| |
| when Attribute_Min => |
| Min_Max; |
| |
| --------- |
| -- Mod -- |
| --------- |
| |
| when Attribute_Mod => |
| |
| -- Note: this attribute is only allowed in Ada 2005 mode, but |
| -- we do not need to test that here, since Mod is only recognized |
| -- as an attribute name in Ada 2005 mode during the parse. |
| |
| Check_E1; |
| Check_Modular_Integer_Type; |
| Resolve (E1, Any_Integer); |
| Set_Etype (N, P_Base_Type); |
| |
| ----------- |
| -- Model -- |
| ----------- |
| |
| when Attribute_Model => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ---------------- |
| -- Model_Emin -- |
| ---------------- |
| |
| when Attribute_Model_Emin => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------- |
| -- Model_Epsilon -- |
| ------------------- |
| |
| when Attribute_Model_Epsilon => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| -------------------- |
| -- Model_Mantissa -- |
| -------------------- |
| |
| when Attribute_Model_Mantissa => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------------- |
| -- Model_Small -- |
| ----------------- |
| |
| when Attribute_Model_Small => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ------------- |
| -- Modulus -- |
| ------------- |
| |
| when Attribute_Modulus => |
| Check_E0; |
| Check_Modular_Integer_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| -------------------- |
| -- Null_Parameter -- |
| -------------------- |
| |
| when Attribute_Null_Parameter => Null_Parameter : declare |
| Parnt : constant Node_Id := Parent (N); |
| GParnt : constant Node_Id := Parent (Parnt); |
| |
| procedure Bad_Null_Parameter (Msg : String); |
| -- Used if bad Null parameter attribute node is found. Issues |
| -- given error message, and also sets the type to Any_Type to |
| -- avoid blowups later on from dealing with a junk node. |
| |
| procedure Must_Be_Imported (Proc_Ent : Entity_Id); |
| -- Called to check that Proc_Ent is imported subprogram |
| |
| ------------------------ |
| -- Bad_Null_Parameter -- |
| ------------------------ |
| |
| procedure Bad_Null_Parameter (Msg : String) is |
| begin |
| Error_Msg_N (Msg, N); |
| Set_Etype (N, Any_Type); |
| end Bad_Null_Parameter; |
| |
| ---------------------- |
| -- Must_Be_Imported -- |
| ---------------------- |
| |
| procedure Must_Be_Imported (Proc_Ent : Entity_Id) is |
| Pent : constant Entity_Id := Ultimate_Alias (Proc_Ent); |
| |
| begin |
| -- Ignore check if procedure not frozen yet (we will get |
| -- another chance when the default parameter is reanalyzed) |
| |
| if not Is_Frozen (Pent) then |
| return; |
| |
| elsif not Is_Imported (Pent) then |
| Bad_Null_Parameter |
| ("Null_Parameter can only be used with imported subprogram"); |
| |
| else |
| return; |
| end if; |
| end Must_Be_Imported; |
| |
| -- Start of processing for Null_Parameter |
| |
| begin |
| Check_Type; |
| Check_E0; |
| Set_Etype (N, P_Type); |
| |
| -- Case of attribute used as default expression |
| |
| if Nkind (Parnt) = N_Parameter_Specification then |
| Must_Be_Imported (Defining_Entity (GParnt)); |
| |
| -- Case of attribute used as actual for subprogram (positional) |
| |
| elsif Nkind (Parnt) in N_Subprogram_Call |
| and then Is_Entity_Name (Name (Parnt)) |
| then |
| Must_Be_Imported (Entity (Name (Parnt))); |
| |
| -- Case of attribute used as actual for subprogram (named) |
| |
| elsif Nkind (Parnt) = N_Parameter_Association |
| and then Nkind (GParnt) in N_Subprogram_Call |
| and then Is_Entity_Name (Name (GParnt)) |
| then |
| Must_Be_Imported (Entity (Name (GParnt))); |
| |
| -- Not an allowed case |
| |
| else |
| Bad_Null_Parameter |
| ("Null_Parameter must be actual or default parameter"); |
| end if; |
| end Null_Parameter; |
| |
| ----------------- |
| -- Object_Size -- |
| ----------------- |
| |
| when Attribute_Object_Size => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| --------- |
| -- Old -- |
| --------- |
| |
| when Attribute_Old => Old : declare |
| procedure Check_References_In_Prefix (Subp_Id : Entity_Id); |
| -- Inspect the contents of the prefix and detect illegal uses of a |
| -- nested 'Old, attribute 'Result or a use of an entity declared in |
| -- the related postcondition expression. Subp_Id is the subprogram to |
| -- which the related postcondition applies. |
| |
| -------------------------------- |
| -- Check_References_In_Prefix -- |
| -------------------------------- |
| |
| procedure Check_References_In_Prefix (Subp_Id : Entity_Id) is |
| function Check_Reference (Nod : Node_Id) return Traverse_Result; |
| -- Detect attribute 'Old, attribute 'Result of a use of an entity |
| -- and perform the appropriate semantic check. |
| |
| --------------------- |
| -- Check_Reference -- |
| --------------------- |
| |
| function Check_Reference (Nod : Node_Id) return Traverse_Result is |
| begin |
| -- Attributes 'Old and 'Result cannot appear in the prefix of |
| -- another attribute 'Old. |
| |
| if Nkind (Nod) = N_Attribute_Reference |
| and then Nam_In (Attribute_Name (Nod), Name_Old, |
| Name_Result) |
| then |
| Error_Msg_Name_1 := Attribute_Name (Nod); |
| Error_Msg_Name_2 := Name_Old; |
| Error_Msg_N |
| ("attribute % cannot appear in the prefix of attribute %", |
| Nod); |
| return Abandon; |
| |
| -- Entities mentioned within the prefix of attribute 'Old must |
| -- be global to the related postcondition. If this is not the |
| -- case, then the scope of the local entity is nested within |
| -- that of the subprogram. |
| |
| elsif Is_Entity_Name (Nod) |
| and then Present (Entity (Nod)) |
| and then Scope_Within (Scope (Entity (Nod)), Subp_Id) |
| then |
| Error_Attr |
| ("prefix of attribute % cannot reference local entities", |
| Nod); |
| return Abandon; |
| |
| -- Otherwise keep inspecting the prefix |
| |
| else |
| return OK; |
| end if; |
| end Check_Reference; |
| |
| procedure Check_References is new Traverse_Proc (Check_Reference); |
| |
| -- Start of processing for Check_References_In_Prefix |
| |
| begin |
| Check_References (P); |
| end Check_References_In_Prefix; |
| |
| -- Local variables |
| |
| Legal : Boolean; |
| Pref_Id : Entity_Id; |
| Pref_Typ : Entity_Id; |
| Spec_Id : Entity_Id; |
| |
| -- Start of processing for Old |
| |
| begin |
| -- The attribute reference is a primary. If any expressions follow, |
| -- then the attribute reference is an indexable object. Transform the |
| -- attribute into an indexed component and analyze it. |
| |
| if Present (E1) then |
| Rewrite (N, |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Make_Attribute_Reference (Loc, |
| Prefix => Relocate_Node (P), |
| Attribute_Name => Name_Old), |
| Expressions => Expressions (N))); |
| Analyze (N); |
| return; |
| end if; |
| |
| Analyze_Attribute_Old_Result (Legal, Spec_Id); |
| |
| -- The aspect or pragma where attribute 'Old resides should be |
| -- associated with a subprogram declaration or a body. If this is not |
| -- the case, then the aspect or pragma is illegal. Return as analysis |
| -- cannot be carried out. |
| |
| -- The exception to this rule is when generating C since in this case |
| -- postconditions are inlined. |
| |
| if No (Spec_Id) |
| and then Modify_Tree_For_C |
| and then In_Inlined_Body |
| then |
| Spec_Id := Entity (P); |
| |
| elsif not Legal then |
| return; |
| end if; |
| |
| -- The prefix must be preanalyzed as the full analysis will take |
| -- place during expansion. |
| |
| Preanalyze_And_Resolve (P); |
| |
| -- Ensure that the prefix does not contain attributes 'Old or 'Result |
| |
| Check_References_In_Prefix (Spec_Id); |
| |
| -- Set the type of the attribute now to prevent cascaded errors |
| |
| Pref_Typ := Etype (P); |
| Set_Etype (N, Pref_Typ); |
| |
| -- Legality checks |
| |
| if Is_Limited_Type (Pref_Typ) then |
| Error_Attr ("attribute % cannot apply to limited objects", P); |
| end if; |
| |
| -- The prefix is a simple name |
| |
| if Is_Entity_Name (P) and then Present (Entity (P)) then |
| Pref_Id := Entity (P); |
| |
| -- Emit a warning when the prefix is a constant. Note that the use |
| -- of Error_Attr would reset the type of N to Any_Type even though |
| -- this is a warning. Use Error_Msg_XXX instead. |
| |
| if Is_Constant_Object (Pref_Id) then |
| Error_Msg_Name_1 := Name_Old; |
| Error_Msg_N |
| ("??attribute % applied to constant has no effect", P); |
| end if; |
| |
| -- Otherwise the prefix is not a simple name |
| |
| else |
| -- Ensure that the prefix of attribute 'Old is an entity when it |
| -- is potentially unevaluated (6.1.1 (27/3)). |
| |
| if Is_Potentially_Unevaluated (N) |
| and then not Statically_Denotes_Object (P) |
| then |
| Uneval_Old_Msg; |
| |
| -- Detect a possible infinite recursion when the prefix denotes |
| -- the related function. |
| |
| -- function Func (...) return ... |
| -- with Post => Func'Old ...; |
| |
| -- The function may be specified in qualified form X.Y where X is |
| -- a protected object and Y is a protected function. In that case |
| -- ensure that the qualified form has an entity. |
| |
| elsif Nkind (P) = N_Function_Call |
| and then Nkind (Name (P)) in N_Has_Entity |
| then |
| Pref_Id := Entity (Name (P)); |
| |
| if Ekind_In (Spec_Id, E_Function, E_Generic_Function) |
| and then Pref_Id = Spec_Id |
| then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N ("!possible infinite recursion<<", P); |
| Error_Msg_N ("\!??Storage_Error ]<<", P); |
| end if; |
| end if; |
| |
| -- The prefix of attribute 'Old may refer to a component of a |
| -- formal parameter. In this case its expansion may generate |
| -- actual subtypes that are referenced in an inner context and |
| -- that must be elaborated within the subprogram itself. If the |
| -- prefix includes a function call, it may involve finalization |
| -- actions that should be inserted when the attribute has been |
| -- rewritten as a declaration. Create a declaration for the prefix |
| -- and insert it at the start of the enclosing subprogram. This is |
| -- an expansion activity that has to be performed now to prevent |
| -- out-of-order issues. |
| |
| -- This expansion is both harmful and not needed in SPARK mode, |
| -- since the formal verification back end relies on the types of |
| -- nodes (hence is not robust w.r.t. a change to base type here), |
| -- and does not suffer from the out-of-order issue described |
| -- above. Thus, this expansion is skipped in SPARK mode. |
| |
| -- The expansion is not relevant for discrete types, which will |
| -- not generate extra declarations, and where use of the base type |
| -- may lead to spurious errors if context is a case. |
| |
| if not GNATprove_Mode then |
| if not Is_Discrete_Type (Pref_Typ) then |
| Pref_Typ := Base_Type (Pref_Typ); |
| end if; |
| |
| Set_Etype (N, Pref_Typ); |
| Set_Etype (P, Pref_Typ); |
| |
| Analyze_Dimension (N); |
| Expand (N); |
| end if; |
| end if; |
| end Old; |
| |
| ---------------------- |
| -- Overlaps_Storage -- |
| ---------------------- |
| |
| when Attribute_Overlaps_Storage => |
| Check_E1; |
| |
| -- Both arguments must be objects of any type |
| |
| Analyze_And_Resolve (P); |
| Analyze_And_Resolve (E1); |
| Check_Object_Reference (P); |
| Check_Object_Reference (E1); |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------ |
| -- Output -- |
| ------------ |
| |
| when Attribute_Output => |
| Check_E2; |
| Check_Stream_Attribute (TSS_Stream_Output); |
| Set_Etype (N, Standard_Void_Type); |
| Resolve (N, Standard_Void_Type); |
| |
| ------------------ |
| -- Partition_ID -- |
| ------------------ |
| |
| when Attribute_Partition_ID => |
| Check_E0; |
| |
| if P_Type /= Any_Type then |
| if not Is_Library_Level_Entity (Entity (P)) then |
| Error_Attr_P |
| ("prefix of % attribute must be library-level entity"); |
| |
| -- The defining entity of prefix should not be declared inside a |
| -- Pure unit. RM E.1(8). Is_Pure was set during declaration. |
| |
| elsif Is_Entity_Name (P) |
| and then Is_Pure (Entity (P)) |
| then |
| Error_Attr_P ("prefix of% attribute must not be declared pure"); |
| end if; |
| end if; |
| |
| Set_Etype (N, Universal_Integer); |
| |
| ------------------------- |
| -- Passed_By_Reference -- |
| ------------------------- |
| |
| when Attribute_Passed_By_Reference => |
| Check_E0; |
| Check_Type; |
| Set_Etype (N, Standard_Boolean); |
| |
| ------------------ |
| -- Pool_Address -- |
| ------------------ |
| |
| when Attribute_Pool_Address => |
| Check_E0; |
| Set_Etype (N, RTE (RE_Address)); |
| |
| --------- |
| -- Pos -- |
| --------- |
| |
| when Attribute_Pos => |
| Check_Discrete_Type; |
| Check_E1; |
| |
| if Is_Boolean_Type (P_Type) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_Name_2 := Chars (P_Type); |
| Check_SPARK_05_Restriction |
| ("attribute% is not allowed for type%", P); |
| end if; |
| |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, Universal_Integer); |
| |
| -------------- |
| -- Position -- |
| -------------- |
| |
| when Attribute_Position => |
| Check_Component; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------- |
| -- Pred -- |
| ---------- |
| |
| when Attribute_Pred => |
| Check_Scalar_Type; |
| Check_E1; |
| |
| if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_Name_2 := Chars (P_Type); |
| Check_SPARK_05_Restriction |
| ("attribute% is not allowed for type%", P); |
| end if; |
| |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| -- Since Pred works on the base type, we normally do no check for the |
| -- floating-point case, since the base type is unconstrained. But we |
| -- make an exception in Check_Float_Overflow mode. |
| |
| if Is_Floating_Point_Type (P_Type) then |
| if not Range_Checks_Suppressed (P_Base_Type) then |
| Set_Do_Range_Check (E1); |
| end if; |
| |
| -- If not modular type, test for overflow check required |
| |
| else |
| if not Is_Modular_Integer_Type (P_Type) |
| and then not Range_Checks_Suppressed (P_Base_Type) |
| then |
| Enable_Range_Check (E1); |
| end if; |
| end if; |
| |
| -------------- |
| -- Priority -- |
| -------------- |
| |
| -- Ada 2005 (AI-327): Dynamic ceiling priorities |
| |
| when Attribute_Priority => |
| if Ada_Version < Ada_2005 then |
| Error_Attr ("% attribute is allowed only in Ada 2005 mode", P); |
| end if; |
| |
| Check_E0; |
| |
| Check_Restriction (No_Dynamic_Priorities, N); |
| |
| -- The prefix must be a protected object (AARM D.5.2 (2/2)) |
| |
| Analyze (P); |
| |
| if Is_Protected_Type (Etype (P)) |
| or else (Is_Access_Type (Etype (P)) |
| and then Is_Protected_Type (Designated_Type (Etype (P)))) |
| then |
| Resolve (P, Etype (P)); |
| else |
| Error_Attr_P ("prefix of % attribute must be a protected object"); |
| end if; |
| |
| Set_Etype (N, Standard_Integer); |
| |
| -- Must be called from within a protected procedure or entry of the |
| -- protected object. |
| |
| declare |
| S : Entity_Id; |
| |
| begin |
| S := Current_Scope; |
| while S /= Etype (P) |
| and then S /= Standard_Standard |
| loop |
| S := Scope (S); |
| end loop; |
| |
| if S = Standard_Standard then |
| Error_Attr ("the attribute % is only allowed inside protected " |
| & "operations", P); |
| end if; |
| end; |
| |
| Validate_Non_Static_Attribute_Function_Call; |
| |
| ----------- |
| -- Range -- |
| ----------- |
| |
| when Attribute_Range => |
| Check_Array_Or_Scalar_Type; |
| Bad_Attribute_For_Predicate; |
| |
| if Ada_Version = Ada_83 |
| and then Is_Scalar_Type (P_Type) |
| and then Comes_From_Source (N) |
| then |
| Error_Attr |
| ("(Ada 83) % attribute not allowed for scalar type", P); |
| end if; |
| |
| ------------ |
| -- Result -- |
| ------------ |
| |
| when Attribute_Result => Result : declare |
| function Denote_Same_Function |
| (Pref_Id : Entity_Id; |
| Spec_Id : Entity_Id) return Boolean; |
| -- Determine whether the entity of the prefix Pref_Id denotes the |
| -- same entity as that of the related subprogram Spec_Id. |
| |
| -------------------------- |
| -- Denote_Same_Function -- |
| -------------------------- |
| |
| function Denote_Same_Function |
| (Pref_Id : Entity_Id; |
| Spec_Id : Entity_Id) return Boolean |
| is |
| Over_Id : constant Entity_Id := Overridden_Operation (Spec_Id); |
| Subp_Spec : constant Node_Id := Parent (Spec_Id); |
| |
| begin |
| -- The prefix denotes the related subprogram |
| |
| if Pref_Id = Spec_Id then |
| return True; |
| |
| -- Account for a special case when attribute 'Result appears in |
| -- the postcondition of a generic function. |
| |
| -- generic |
| -- function Gen_Func return ... |
| -- with Post => Gen_Func'Result ...; |
| |
| -- When the generic function is instantiated, the Chars field of |
| -- the instantiated prefix still denotes the name of the generic |
| -- function. Note that any preemptive transformation is impossible |
| -- without a proper analysis. The structure of the wrapper package |
| -- is as follows: |
| |
| -- package Anon_Gen_Pack is |
| -- <subtypes and renamings> |
| -- function Subp_Decl return ...; -- (!) |
| -- pragma Postcondition (Gen_Func'Result ...); -- (!) |
| -- function Gen_Func ... renames Subp_Decl; |
| -- end Anon_Gen_Pack; |
| |
| elsif Nkind (Subp_Spec) = N_Function_Specification |
| and then Present (Generic_Parent (Subp_Spec)) |
| and then Ekind_In (Pref_Id, E_Generic_Function, E_Function) |
| then |
| if Generic_Parent (Subp_Spec) = Pref_Id then |
| return True; |
| |
| elsif Present (Alias (Pref_Id)) |
| and then Alias (Pref_Id) = Spec_Id |
| then |
| return True; |
| end if; |
| |
| -- Account for a special case where a primitive of a tagged type |
| -- inherits a class-wide postcondition from a parent type. In this |
| -- case the prefix of attribute 'Result denotes the overriding |
| -- primitive. |
| |
| elsif Present (Over_Id) and then Pref_Id = Over_Id then |
| return True; |
| end if; |
| |
| -- Otherwise the prefix does not denote the related subprogram |
| |
| return False; |
| end Denote_Same_Function; |
| |
| -- Local variables |
| |
| In_Inlined_C_Postcondition : constant Boolean := |
| Modify_Tree_For_C |
| and then In_Inlined_Body; |
| |
| Legal : Boolean; |
| Pref_Id : Entity_Id; |
| Spec_Id : Entity_Id; |
| |
| -- Start of processing for Result |
| |
| begin |
| -- The attribute reference is a primary. If any expressions follow, |
| -- then the attribute reference is an indexable object. Transform the |
| -- attribute into an indexed component and analyze it. |
| |
| if Present (E1) then |
| Rewrite (N, |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Make_Attribute_Reference (Loc, |
| Prefix => Relocate_Node (P), |
| Attribute_Name => Name_Result), |
| Expressions => Expressions (N))); |
| Analyze (N); |
| return; |
| end if; |
| |
| Analyze_Attribute_Old_Result (Legal, Spec_Id); |
| |
| -- The aspect or pragma where attribute 'Result resides should be |
| -- associated with a subprogram declaration or a body. If this is not |
| -- the case, then the aspect or pragma is illegal. Return as analysis |
| -- cannot be carried out. |
| |
| -- The exception to this rule is when generating C since in this case |
| -- postconditions are inlined. |
| |
| if No (Spec_Id) and then In_Inlined_C_Postcondition then |
| Spec_Id := Entity (P); |
| |
| elsif not Legal then |
| return; |
| end if; |
| |
| -- Attribute 'Result is part of a _Postconditions procedure. There is |
| -- no need to perform the semantic checks below as they were already |
| -- verified when the attribute was analyzed in its original context. |
| -- Instead, rewrite the attribute as a reference to formal parameter |
| -- _Result of the _Postconditions procedure. |
| |
| if Chars (Spec_Id) = Name_uPostconditions |
| or else |
| (In_Inlined_C_Postcondition |
| and then Nkind (Parent (Spec_Id)) = N_Block_Statement) |
| then |
| Rewrite (N, Make_Identifier (Loc, Name_uResult)); |
| |
| -- The type of formal parameter _Result is that of the function |
| -- encapsulating the _Postconditions procedure. Resolution must |
| -- be carried out against the function return type. |
| |
| Analyze_And_Resolve (N, Etype (Scope (Spec_Id))); |
| |
| -- Otherwise attribute 'Result appears in its original context and |
| -- all semantic checks should be carried out. |
| |
| else |
| -- Verify the legality of the prefix. It must denotes the entity |
| -- of the related [generic] function. |
| |
| if Is_Entity_Name (P) then |
| Pref_Id := Entity (P); |
| |
| if Ekind_In (Pref_Id, E_Function, E_Generic_Function) |
| and then Ekind (Spec_Id) = Ekind (Pref_Id) |
| then |
| if Denote_Same_Function (Pref_Id, Spec_Id) then |
| |
| -- Correct the prefix of the attribute when the context |
| -- is a generic function. |
| |
| if Pref_Id /= Spec_Id then |
| Rewrite (P, New_Occurrence_Of (Spec_Id, Loc)); |
| Analyze (P); |
| end if; |
| |
| Set_Etype (N, Etype (Spec_Id)); |
| |
| -- Otherwise the prefix denotes some unrelated function |
| |
| else |
| Error_Msg_Name_2 := Chars (Spec_Id); |
| Error_Attr |
| ("incorrect prefix for attribute %, expected %", P); |
| end if; |
| |
| -- Otherwise the prefix denotes some other form of subprogram |
| -- entity. |
| |
| else |
| Error_Attr |
| ("attribute % can only appear in postcondition of " |
| & "function", P); |
| end if; |
| |
| -- Otherwise the prefix is illegal |
| |
| else |
| Error_Msg_Name_2 := Chars (Spec_Id); |
| Error_Attr ("incorrect prefix for attribute %, expected %", P); |
| end if; |
| end if; |
| end Result; |
| |
| ------------------ |
| -- Range_Length -- |
| ------------------ |
| |
| when Attribute_Range_Length => |
| Check_E0; |
| Check_Discrete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------- |
| -- Read -- |
| ---------- |
| |
| when Attribute_Read => |
| Check_E2; |
| Check_Stream_Attribute (TSS_Stream_Read); |
| Set_Etype (N, Standard_Void_Type); |
| Resolve (N, Standard_Void_Type); |
| Note_Possible_Modification (E2, Sure => True); |
| |
| --------- |
| -- Ref -- |
| --------- |
| |
| when Attribute_Ref => |
| Check_E1; |
| Analyze (P); |
| |
| if Nkind (P) /= N_Expanded_Name |
| or else not Is_RTE (P_Type, RE_Address) |
| then |
| Error_Attr_P ("prefix of % attribute must be System.Address"); |
| end if; |
| |
| Analyze_And_Resolve (E1, Any_Integer); |
| Set_Etype (N, RTE (RE_Address)); |
| |
| --------------- |
| -- Remainder -- |
| --------------- |
| |
| when Attribute_Remainder => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| Resolve (E2, P_Base_Type); |
| |
| --------------------- |
| -- Restriction_Set -- |
| --------------------- |
| |
| when Attribute_Restriction_Set => Restriction_Set : declare |
| R : Restriction_Id; |
| U : Node_Id; |
| Unam : Unit_Name_Type; |
| |
| begin |
| Check_E1; |
| Analyze (P); |
| Check_System_Prefix; |
| |
| -- No_Dependence case |
| |
| if Nkind (E1) = N_Parameter_Association then |
| pragma Assert (Chars (Selector_Name (E1)) = Name_No_Dependence); |
| U := Explicit_Actual_Parameter (E1); |
| |
| if not OK_No_Dependence_Unit_Name (U) then |
| Set_Boolean_Result (N, False); |
| Error_Attr; |
| end if; |
| |
| -- See if there is an entry already in the table. That's the |
| -- case in which we can return True. |
| |
| for J in No_Dependences.First .. No_Dependences.Last loop |
| if Designate_Same_Unit (U, No_Dependences.Table (J).Unit) |
| and then No_Dependences.Table (J).Warn = False |
| then |
| Set_Boolean_Result (N, True); |
| return; |
| end if; |
| end loop; |
| |
| -- If not in the No_Dependence table, result is False |
| |
| Set_Boolean_Result (N, False); |
| |
| -- In this case, we must ensure that the binder will reject any |
| -- other unit in the partition that sets No_Dependence for this |
| -- unit. We do that by making an entry in the special table kept |
| -- for this purpose (if the entry is not there already). |
| |
| Unam := Get_Spec_Name (Get_Unit_Name (U)); |
| |
| for J in Restriction_Set_Dependences.First .. |
| Restriction_Set_Dependences.Last |
| loop |
| if Restriction_Set_Dependences.Table (J) = Unam then |
| return; |
| end if; |
| end loop; |
| |
| Restriction_Set_Dependences.Append (Unam); |
| |
| -- Normal restriction case |
| |
| else |
| if Nkind (E1) /= N_Identifier then |
| Set_Boolean_Result (N, False); |
| Error_Attr ("attribute % requires restriction identifier", E1); |
| |
| else |
| R := Get_Restriction_Id (Process_Restriction_Synonyms (E1)); |
| |
| if R = Not_A_Restriction_Id then |
| Set_Boolean_Result (N, False); |
| Error_Msg_Node_1 := E1; |
| Error_Attr ("invalid restriction identifier &", E1); |
| |
| elsif R not in Partition_Boolean_Restrictions then |
| Set_Boolean_Result (N, False); |
| Error_Msg_Node_1 := E1; |
| Error_Attr |
| ("& is not a boolean partition-wide restriction", E1); |
| end if; |
| |
| if Restriction_Active (R) then |
| Set_Boolean_Result (N, True); |
| else |
| Check_Restriction (R, N); |
| Set_Boolean_Result (N, False); |
| end if; |
| end if; |
| end if; |
| end Restriction_Set; |
| |
| ----------- |
| -- Round -- |
| ----------- |
| |
| when Attribute_Round => |
| Check_E1; |
| Check_Decimal_Fixed_Point_Type; |
| Set_Etype (N, P_Base_Type); |
| |
| -- Because the context is universal_real (3.5.10(12)) it is a |
| -- legal context for a universal fixed expression. This is the |
| -- only attribute whose functional description involves U_R. |
| |
| if Etype (E1) = Universal_Fixed then |
| declare |
| Conv : constant Node_Id := Make_Type_Conversion (Loc, |
| Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc), |
| Expression => Relocate_Node (E1)); |
| |
| begin |
| Rewrite (E1, Conv); |
| Analyze (E1); |
| end; |
| end if; |
| |
| Resolve (E1, Any_Real); |
| |
| -------------- |
| -- Rounding -- |
| -------------- |
| |
| when Attribute_Rounding => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| --------------- |
| -- Safe_Emax -- |
| --------------- |
| |
| when Attribute_Safe_Emax => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------- |
| -- Safe_First -- |
| ---------------- |
| |
| when Attribute_Safe_First => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ---------------- |
| -- Safe_Large -- |
| ---------------- |
| |
| when Attribute_Safe_Large => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| --------------- |
| -- Safe_Last -- |
| --------------- |
| |
| when Attribute_Safe_Last => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Universal_Real); |
| |
| ---------------- |
| -- Safe_Small -- |
| ---------------- |
| |
| when Attribute_Safe_Small => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| -------------------------- |
| -- Scalar_Storage_Order -- |
| -------------------------- |
| |
| when Attribute_Scalar_Storage_Order => Scalar_Storage_Order : declare |
| Ent : Entity_Id := Empty; |
| |
| begin |
| Check_E0; |
| Check_Type; |
| |
| if not (Is_Record_Type (P_Type) or else Is_Array_Type (P_Type)) then |
| |
| -- The attribute applies to generic private types (in which case |
| -- the legality rule is applied in the instance) as well as to |
| -- composite types. For noncomposite types it always returns the |
| -- default bit order for the target. |
| -- Allowing formal private types was originally introduced in |
| -- GNAT_Mode only, to compile instances of Sequential_IO, but |
| -- users find it more generally useful in generic units. |
| |
| if not (Is_Generic_Type (P_Type) and then Is_Private_Type (P_Type)) |
| and then not In_Instance |
| then |
| Error_Attr_P |
| ("prefix of % attribute must be record or array type"); |
| |
| elsif not Is_Generic_Type (P_Type) then |
| if Bytes_Big_Endian then |
| Ent := RTE (RE_High_Order_First); |
| else |
| Ent := RTE (RE_Low_Order_First); |
| end if; |
| end if; |
| |
| elsif Bytes_Big_Endian xor Reverse_Storage_Order (P_Type) then |
| Ent := RTE (RE_High_Order_First); |
| |
| else |
| Ent := RTE (RE_Low_Order_First); |
| end if; |
| |
| if Present (Ent) then |
| Rewrite (N, New_Occurrence_Of (Ent, Loc)); |
| end if; |
| |
| Set_Etype (N, RTE (RE_Bit_Order)); |
| Resolve (N); |
| |
| -- Reset incorrect indication of staticness |
| |
| Set_Is_Static_Expression (N, False); |
| end Scalar_Storage_Order; |
| |
| ----------- |
| -- Scale -- |
| ----------- |
| |
| when Attribute_Scale => |
| Check_E0; |
| Check_Decimal_Fixed_Point_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------- |
| -- Scaling -- |
| ------------- |
| |
| when Attribute_Scaling => |
| Check_Floating_Point_Type_2; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ------------------ |
| -- Signed_Zeros -- |
| ------------------ |
| |
| when Attribute_Signed_Zeros => |
| Check_Floating_Point_Type_0; |
| Set_Etype (N, Standard_Boolean); |
| |
| ---------- |
| -- Size -- |
| ---------- |
| |
| when Attribute_Size |
| | Attribute_VADS_Size |
| => |
| Check_E0; |
| |
| -- If prefix is parameterless function call, rewrite and resolve |
| -- as such. |
| |
| if Is_Entity_Name (P) |
| and then Ekind (Entity (P)) = E_Function |
| then |
| Resolve (P); |
| |
| -- Similar processing for a protected function call |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Ekind (Entity (Selector_Name (P))) = E_Function |
| then |
| Resolve (P); |
| end if; |
| |
| if Is_Object_Reference (P) then |
| Check_Object_Reference (P); |
| |
| elsif Is_Entity_Name (P) |
| and then (Is_Type (Entity (P)) |
| or else Ekind (Entity (P)) = E_Enumeration_Literal) |
| then |
| null; |
| |
| elsif Nkind (P) = N_Type_Conversion |
| and then not Comes_From_Source (P) |
| then |
| null; |
| |
| -- Some other compilers allow dubious use of X'???'Size |
| |
| elsif Relaxed_RM_Semantics |
| and then Nkind (P) = N_Attribute_Reference |
| then |
| null; |
| |
| else |
| Error_Attr_P ("invalid prefix for % attribute"); |
| end if; |
| |
| Check_Not_Incomplete_Type; |
| Check_Not_CPP_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| -- If we are processing pragmas Compile_Time_Warning and Compile_ |
| -- Time_Errors after the back end has been called and this occurrence |
| -- of 'Size is known at compile time then it is safe to perform this |
| -- evaluation. Needed to perform the static evaluation of the full |
| -- boolean expression of these pragmas. |
| |
| if In_Compile_Time_Warning_Or_Error |
| and then Is_Entity_Name (P) |
| and then (Is_Type (Entity (P)) |
| or else Ekind (Entity (P)) = E_Enumeration_Literal) |
| and then Size_Known_At_Compile_Time (Entity (P)) |
| then |
| Rewrite (N, Make_Integer_Literal (Sloc (N), Esize (Entity (P)))); |
| Analyze (N); |
| end if; |
| |
| ----------- |
| -- Small -- |
| ----------- |
| |
| when Attribute_Small => |
| Check_E0; |
| Check_Real_Type; |
| Set_Etype (N, Universal_Real); |
| |
| ------------------ |
| -- Storage_Pool -- |
| ------------------ |
| |
| when Attribute_Storage_Pool |
| | Attribute_Simple_Storage_Pool |
| => |
| Check_E0; |
| |
| if Is_Access_Type (P_Type) then |
| if Ekind (P_Type) = E_Access_Subprogram_Type then |
| Error_Attr_P |
| ("cannot use % attribute for access-to-subprogram type"); |
| end if; |
| |
| -- Set appropriate entity |
| |
| if Present (Associated_Storage_Pool (Root_Type (P_Type))) then |
| Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type))); |
| else |
| Set_Entity (N, RTE (RE_Global_Pool_Object)); |
| end if; |
| |
| if Attr_Id = Attribute_Storage_Pool then |
| if Present (Get_Rep_Pragma (Etype (Entity (N)), |
| Name_Simple_Storage_Pool_Type)) |
| then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_N |
| ("cannot use % attribute for type with simple storage " |
| & "pool<<", N); |
| Error_Msg_N ("\Program_Error [<<", N); |
| |
| Rewrite |
| (N, Make_Raise_Program_Error |
| (Sloc (N), Reason => PE_Explicit_Raise)); |
| end if; |
| |
| Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool))); |
| |
| -- In the Simple_Storage_Pool case, verify that the pool entity is |
| -- actually of a simple storage pool type, and set the attribute's |
| -- type to the pool object's type. |
| |
| else |
| if not Present (Get_Rep_Pragma (Etype (Entity (N)), |
| Name_Simple_Storage_Pool_Type)) |
| then |
| Error_Attr_P |
| ("cannot use % attribute for type without simple " & |
| "storage pool"); |
| end if; |
| |
| Set_Etype (N, Etype (Entity (N))); |
| end if; |
| |
| -- Validate_Remote_Access_To_Class_Wide_Type for attribute |
| -- Storage_Pool since this attribute is not defined for such |
| -- types (RM E.2.3(22)). |
| |
| Validate_Remote_Access_To_Class_Wide_Type (N); |
| |
| else |
| Error_Attr_P ("prefix of % attribute must be access type"); |
| end if; |
| |
| ------------------ |
| -- Storage_Size -- |
| ------------------ |
| |
| when Attribute_Storage_Size => |
| Check_E0; |
| |
| if Is_Task_Type (P_Type) then |
| Set_Etype (N, Universal_Integer); |
| |
| -- Use with tasks is an obsolescent feature |
| |
| Check_Restriction (No_Obsolescent_Features, P); |
| |
| elsif Is_Access_Type (P_Type) then |
| if Ekind (P_Type) = E_Access_Subprogram_Type then |
| Error_Attr_P |
| ("cannot use % attribute for access-to-subprogram type"); |
| end if; |
| |
| if Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| Check_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| -- Validate_Remote_Access_To_Class_Wide_Type for attribute |
| -- Storage_Size since this attribute is not defined for |
| -- such types (RM E.2.3(22)). |
| |
| Validate_Remote_Access_To_Class_Wide_Type (N); |
| |
| -- The prefix is allowed to be an implicit dereference of an |
| -- access value designating a task. |
| |
| else |
| Check_Task_Prefix; |
| Set_Etype (N, Universal_Integer); |
| end if; |
| |
| else |
| Error_Attr_P ("prefix of % attribute must be access or task type"); |
| end if; |
| |
| ------------------ |
| -- Storage_Unit -- |
| ------------------ |
| |
| when Attribute_Storage_Unit => |
| Standard_Attribute (Ttypes.System_Storage_Unit); |
| |
| ----------------- |
| -- Stream_Size -- |
| ----------------- |
| |
| when Attribute_Stream_Size => |
| Check_E0; |
| Check_Type; |
| |
| if Is_Entity_Name (P) |
| and then Is_Elementary_Type (Entity (P)) |
| then |
| Set_Etype (N, Universal_Integer); |
| else |
| Error_Attr_P ("invalid prefix for % attribute"); |
| end if; |
| |
| --------------- |
| -- Stub_Type -- |
| --------------- |
| |
| when Attribute_Stub_Type => |
| Check_Type; |
| Check_E0; |
| |
| if Is_Remote_Access_To_Class_Wide_Type (Base_Type (P_Type)) then |
| |
| -- For a real RACW [sub]type, use corresponding stub type |
| |
| if not Is_Generic_Type (P_Type) then |
| Rewrite (N, |
| New_Occurrence_Of |
| (Corresponding_Stub_Type (Base_Type (P_Type)), Loc)); |
| |
| -- For a generic type (that has been marked as an RACW using the |
| -- Remote_Access_Type aspect or pragma), use a generic RACW stub |
| -- type. Note that if the actual is not a remote access type, the |
| -- instantiation will fail. |
| |
| else |
| -- Note: we go to the underlying type here because the view |
| -- returned by RTE (RE_RACW_Stub_Type) might be incomplete. |
| |
| Rewrite (N, |
| New_Occurrence_Of |
| (Underlying_Type (RTE (RE_RACW_Stub_Type)), Loc)); |
| end if; |
| |
| else |
| Error_Attr_P |
| ("prefix of% attribute must be remote access-to-class-wide"); |
| end if; |
| |
| ---------- |
| -- Succ -- |
| ---------- |
| |
| when Attribute_Succ => |
| Check_Scalar_Type; |
| Check_E1; |
| |
| if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_Name_2 := Chars (P_Type); |
| Check_SPARK_05_Restriction |
| ("attribute% is not allowed for type%", P); |
| end if; |
| |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| -- Since Pred works on the base type, we normally do no check for the |
| -- floating-point case, since the base type is unconstrained. But we |
| -- make an exception in Check_Float_Overflow mode. |
| |
| if Is_Floating_Point_Type (P_Type) then |
| if not Range_Checks_Suppressed (P_Base_Type) then |
| Set_Do_Range_Check (E1); |
| end if; |
| |
| -- If not modular type, test for overflow check required |
| |
| else |
| if not Is_Modular_Integer_Type (P_Type) |
| and then not Range_Checks_Suppressed (P_Base_Type) |
| then |
| Enable_Range_Check (E1); |
| end if; |
| end if; |
| |
| -------------------------------- |
| -- System_Allocator_Alignment -- |
| -------------------------------- |
| |
| when Attribute_System_Allocator_Alignment => |
| Standard_Attribute (Ttypes.System_Allocator_Alignment); |
| |
| --------- |
| -- Tag -- |
| --------- |
| |
| when Attribute_Tag => |
| Check_E0; |
| Check_Dereference; |
| |
| if not Is_Tagged_Type (P_Type) then |
| Error_Attr_P ("prefix of % attribute must be tagged"); |
| |
| -- Next test does not apply to generated code why not, and what does |
| -- the illegal reference mean??? |
| |
| elsif Is_Object_Reference (P) |
| and then not Is_Class_Wide_Type (P_Type) |
| and then Comes_From_Source (N) |
| then |
| Error_Attr_P |
| ("% attribute can only be applied to objects " & |
| "of class - wide type"); |
| end if; |
| |
| -- The prefix cannot be an incomplete type. However, references to |
| -- 'Tag can be generated when expanding interface conversions, and |
| -- this is legal. |
| |
| if Comes_From_Source (N) then |
| Check_Not_Incomplete_Type; |
| end if; |
| |
| -- Set appropriate type |
| |
| Set_Etype (N, RTE (RE_Tag)); |
| |
| ----------------- |
| -- Target_Name -- |
| ----------------- |
| |
| when Attribute_Target_Name => Target_Name : declare |
| TN : constant String := Sdefault.Target_Name.all; |
| TL : Natural; |
| |
| begin |
| Check_Standard_Prefix; |
| |
| TL := TN'Last; |
| |
| if TN (TL) = '/' or else TN (TL) = '\' then |
| TL := TL - 1; |
| end if; |
| |
| Rewrite (N, |
| Make_String_Literal (Loc, |
| Strval => TN (TN'First .. TL))); |
| Analyze_And_Resolve (N, Standard_String); |
| Set_Is_Static_Expression (N, True); |
| end Target_Name; |
| |
| ---------------- |
| -- Terminated -- |
| ---------------- |
| |
| when Attribute_Terminated => |
| Check_E0; |
| Set_Etype (N, Standard_Boolean); |
| Check_Task_Prefix; |
| |
| ---------------- |
| -- To_Address -- |
| ---------------- |
| |
| when Attribute_To_Address => To_Address : declare |
| Val : Uint; |
| |
| begin |
| Check_E1; |
| Analyze (P); |
| Check_System_Prefix; |
| |
| Generate_Reference (RTE (RE_Address), P); |
| Analyze_And_Resolve (E1, Any_Integer); |
| Set_Etype (N, RTE (RE_Address)); |
| |
| if Is_Static_Expression (E1) then |
| Set_Is_Static_Expression (N, True); |
| end if; |
| |
| -- OK static expression case, check range and set appropriate type |
| |
| if Is_OK_Static_Expression (E1) then |
| Val := Expr_Value (E1); |
| |
| if Val < -(2 ** UI_From_Int (Standard'Address_Size - 1)) |
| or else |
| Val > 2 ** UI_From_Int (Standard'Address_Size) - 1 |
| then |
| Error_Attr ("address value out of range for % attribute", E1); |
| end if; |
| |
| -- In most cases the expression is a numeric literal or some other |
| -- address expression, but if it is a declared constant it may be |
| -- of a compatible type that must be left on the node. |
| |
| if Is_Entity_Name (E1) then |
| null; |
| |
| -- Set type to universal integer if negative |
| |
| elsif Val < 0 then |
| Set_Etype (E1, Universal_Integer); |
| |
| -- Otherwise set type to Unsigned_64 to accommodate max values |
| |
| else |
| Set_Etype (E1, Standard_Unsigned_64); |
| end if; |
| end if; |
| |
| Set_Is_Static_Expression (N, True); |
| end To_Address; |
| |
| ------------ |
| -- To_Any -- |
| ------------ |
| |
| when Attribute_To_Any => |
| Check_E1; |
| Check_PolyORB_Attribute; |
| Set_Etype (N, RTE (RE_Any)); |
| |
| ---------------- |
| -- Truncation -- |
| ---------------- |
| |
| when Attribute_Truncation => |
| Check_Floating_Point_Type_1; |
| Resolve (E1, P_Base_Type); |
| Set_Etype (N, P_Base_Type); |
| |
| ---------------- |
| -- Type_Class -- |
| ---------------- |
| |
| when Attribute_Type_Class => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, RTE (RE_Type_Class)); |
| |
| -------------- |
| -- TypeCode -- |
| -------------- |
| |
| when Attribute_TypeCode => |
| Check_E0; |
| Check_PolyORB_Attribute; |
| Set_Etype (N, RTE (RE_TypeCode)); |
| |
| -------------- |
| -- Type_Key -- |
| -------------- |
| |
| when Attribute_Type_Key => Type_Key : declare |
| Full_Name : constant String_Id := |
| Fully_Qualified_Name_String (Entity (P)); |
| |
| CRC : CRC32; |
| -- The computed signature for the type |
| |
| Deref : Boolean; |
| -- To simplify the handling of mutually recursive types, follow a |
| -- single dereference link in a composite type. |
| |
| procedure Compute_Type_Key (T : Entity_Id); |
| -- Create a CRC integer from the declaration of the type. For a |
| -- composite type, fold in the representation of its components in |
| -- recursive fashion. We use directly the source representation of |
| -- the types involved. |
| |
| ---------------------- |
| -- Compute_Type_Key -- |
| ---------------------- |
| |
| procedure Compute_Type_Key (T : Entity_Id) is |
| Buffer : Source_Buffer_Ptr; |
| P_Max : Source_Ptr; |
| P_Min : Source_Ptr; |
| Rep : Node_Id; |
| SFI : Source_File_Index; |
| |
| procedure Process_One_Declaration; |
| -- Update CRC with the characters of one type declaration, or a |
| -- representation pragma that applies to the type. |
| |
| ----------------------------- |
| -- Process_One_Declaration -- |
| ----------------------------- |
| |
| procedure Process_One_Declaration is |
| begin |
| -- Scan type declaration, skipping blanks |
| |
| for Ptr in P_Min .. P_Max loop |
| if Buffer (Ptr) /= ' ' then |
| System.CRC32.Update (CRC, Buffer (Ptr)); |
| end if; |
| end loop; |
| end Process_One_Declaration; |
| |
| -- Start of processing for Compute_Type_Key |
| |
| begin |
| if Is_Itype (T) then |
| return; |
| end if; |
| |
| -- If the type is declared in Standard, there is no source, so |
| -- just use its name. |
| |
| if Scope (T) = Standard_Standard then |
| declare |
| Name : constant String := Get_Name_String (Chars (T)); |
| begin |
| for J in Name'Range loop |
| System.CRC32.Update (CRC, Name (J)); |
| end loop; |
| end; |
| |
| return; |
| end if; |
| |
| Sloc_Range (Enclosing_Declaration (T), P_Min, P_Max); |
| SFI := Get_Source_File_Index (P_Min); |
| pragma Assert (SFI = Get_Source_File_Index (P_Max)); |
| Buffer := Source_Text (SFI); |
| |
| Process_One_Declaration; |
| |
| -- Recurse on relevant component types |
| |
| if Is_Array_Type (T) then |
| Compute_Type_Key (Component_Type (T)); |
| |
| elsif Is_Access_Type (T) then |
| if not Deref then |
| Deref := True; |
| Compute_Type_Key (Designated_Type (T)); |
| end if; |
| |
| elsif Is_Derived_Type (T) then |
| Compute_Type_Key (Etype (T)); |
| |
| elsif Is_Record_Type (T) then |
| declare |
| Comp : Entity_Id; |
| begin |
| Comp := First_Component (T); |
| while Present (Comp) loop |
| Compute_Type_Key (Etype (Comp)); |
| Next_Component (Comp); |
| end loop; |
| end; |
| end if; |
| |
| if Is_First_Subtype (T) then |
| |
| -- Fold in representation aspects for the type, which appear in |
| -- the same source buffer. If the representation aspects are in |
| -- a different source file, then skip them; they apply to some |
| -- other type, perhaps one we're derived from. |
| |
| Rep := First_Rep_Item (T); |
| |
| while Present (Rep) loop |
| if Comes_From_Source (Rep) then |
| Sloc_Range (Rep, P_Min, P_Max); |
| |
| if SFI = Get_Source_File_Index (P_Min) then |
| pragma Assert (SFI = Get_Source_File_Index (P_Max)); |
| Process_One_Declaration; |
| end if; |
| end if; |
| |
| Rep := Next_Rep_Item (Rep); |
| end loop; |
| end if; |
| end Compute_Type_Key; |
| |
| -- Start of processing for Type_Key |
| |
| begin |
| Check_E0; |
| Check_Type; |
| |
| Start_String; |
| Deref := False; |
| |
| -- Copy all characters in Full_Name but the trailing NUL |
| |
| for J in 1 .. String_Length (Full_Name) - 1 loop |
| Store_String_Char (Get_String_Char (Full_Name, Pos (J))); |
| end loop; |
| |
| -- Compute CRC and convert it to string one character at a time, so |
| -- as not to use Image within the compiler. |
| |
| Initialize (CRC); |
| Compute_Type_Key (Entity (P)); |
| |
| if not Is_Frozen (Entity (P)) then |
| Error_Msg_N ("premature usage of Type_Key?", N); |
| end if; |
| |
| while CRC > 0 loop |
| Store_String_Char (Character'Val (48 + (CRC rem 10))); |
| CRC := CRC / 10; |
| end loop; |
| |
| Rewrite (N, Make_String_Literal (Loc, End_String)); |
| Analyze_And_Resolve (N, Standard_String); |
| end Type_Key; |
| |
| ----------------------- |
| -- Unbiased_Rounding -- |
| ----------------------- |
| |
| when Attribute_Unbiased_Rounding => |
| Check_Floating_Point_Type_1; |
| Set_Etype (N, P_Base_Type); |
| Resolve (E1, P_Base_Type); |
| |
| ---------------------- |
| -- Unchecked_Access -- |
| ---------------------- |
| |
| when Attribute_Unchecked_Access => |
| if Comes_From_Source (N) then |
| Check_Restriction (No_Unchecked_Access, N); |
| end if; |
| |
| Analyze_Access_Attribute; |
| Check_Not_Incomplete_Type; |
| |
| ------------------------- |
| -- Unconstrained_Array -- |
| ------------------------- |
| |
| when Attribute_Unconstrained_Array => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Standard_Boolean); |
| Set_Is_Static_Expression (N, True); |
| |
| ------------------------------ |
| -- Universal_Literal_String -- |
| ------------------------------ |
| |
| -- This is a GNAT specific attribute whose prefix must be a named |
| -- number where the expression is either a single numeric literal, |
| -- or a numeric literal immediately preceded by a minus sign. The |
| -- result is equivalent to a string literal containing the text of |
| -- the literal as it appeared in the source program with a possible |
| -- leading minus sign. |
| |
| when Attribute_Universal_Literal_String => |
| Check_E0; |
| |
| if not Is_Entity_Name (P) |
| or else Ekind (Entity (P)) not in Named_Kind |
| then |
| Error_Attr_P ("prefix for % attribute must be named number"); |
| |
| else |
| declare |
| Expr : Node_Id; |
| Negative : Boolean; |
| S : Source_Ptr; |
| Src : Source_Buffer_Ptr; |
| |
| begin |
| Expr := Original_Node (Expression (Parent (Entity (P)))); |
| |
| if Nkind (Expr) = N_Op_Minus then |
| Negative := True; |
| Expr := Original_Node (Right_Opnd (Expr)); |
| else |
| Negative := False; |
| end if; |
| |
| if not Nkind_In (Expr, N_Integer_Literal, N_Real_Literal) then |
| Error_Attr |
| ("named number for % attribute must be simple literal", N); |
| end if; |
| |
| -- Build string literal corresponding to source literal text |
| |
| Start_String; |
| |
| if Negative then |
| Store_String_Char (Get_Char_Code ('-')); |
| end if; |
| |
| S := Sloc (Expr); |
| Src := Source_Text (Get_Source_File_Index (S)); |
| |
| while Src (S) /= ';' and then Src (S) /= ' ' loop |
| Store_String_Char (Get_Char_Code (Src (S))); |
| S := S + 1; |
| end loop; |
| |
| -- Now we rewrite the attribute with the string literal |
| |
| Rewrite (N, |
| Make_String_Literal (Loc, End_String)); |
| Analyze (N); |
| Set_Is_Static_Expression (N, True); |
| end; |
| end if; |
| |
| ------------------------- |
| -- Unrestricted_Access -- |
| ------------------------- |
| |
| -- This is a GNAT specific attribute which is like Access except that |
| -- all scope checks and checks for aliased views are omitted. It is |
| -- documented as being equivalent to the use of the Address attribute |
| -- followed by an unchecked conversion to the target access type. |
| |
| when Attribute_Unrestricted_Access => |
| |
| -- If from source, deal with relevant restrictions |
| |
| if Comes_From_Source (N) then |
| Check_Restriction (No_Unchecked_Access, N); |
| |
| if Nkind (P) in N_Has_Entity |
| and then Present (Entity (P)) |
| and then Is_Object (Entity (P)) |
| then |
| Check_Restriction (No_Implicit_Aliasing, N); |
| end if; |
| end if; |
| |
| if Is_Entity_Name (P) then |
| Set_Address_Taken (Entity (P)); |
| end if; |
| |
| -- It might seem reasonable to call Address_Checks here to apply the |
| -- same set of semantic checks that we enforce for 'Address (after |
| -- all we document Unrestricted_Access as being equivalent to the |
| -- use of Address followed by an Unchecked_Conversion). However, if |
| -- we do enable these checks, we get multiple failures in both the |
| -- compiler run-time and in our regression test suite, so we leave |
| -- out these checks for now. To be investigated further some time??? |
| |
| -- Address_Checks; |
| |
| -- Now complete analysis using common access processing |
| |
| Analyze_Access_Attribute; |
| |
| ------------ |
| -- Update -- |
| ------------ |
| |
| when Attribute_Update => Update : declare |
| Common_Typ : Entity_Id; |
| -- The common type of a multiple component update for a record |
| |
| Comps : Elist_Id := No_Elist; |
| -- A list used in the resolution of a record update. It contains the |
| -- entities of all record components processed so far. |
| |
| procedure Analyze_Array_Component_Update (Assoc : Node_Id); |
| -- Analyze and resolve array_component_association Assoc against the |
| -- index of array type P_Type. |
| |
| procedure Analyze_Record_Component_Update (Comp : Node_Id); |
| -- Analyze and resolve record_component_association Comp against |
| -- record type P_Type. |
| |
| ------------------------------------ |
| -- Analyze_Array_Component_Update -- |
| ------------------------------------ |
| |
| procedure Analyze_Array_Component_Update (Assoc : Node_Id) is |
| Expr : Node_Id; |
| High : Node_Id; |
| Index : Node_Id; |
| Index_Typ : Entity_Id; |
| Low : Node_Id; |
| |
| begin |
| -- The current association contains a sequence of indexes denoting |
| -- an element of a multidimensional array: |
| |
| -- (Index_1, ..., Index_N) |
| |
| -- Examine each individual index and resolve it against the proper |
| -- index type of the array. |
| |
| if Nkind (First (Choices (Assoc))) = N_Aggregate then |
| Expr := First (Choices (Assoc)); |
| while Present (Expr) loop |
| |
| -- The use of others is illegal (SPARK RM 4.4.1(12)) |
| |
| if Nkind (Expr) = N_Others_Choice then |
| Error_Attr |
| ("others choice not allowed in attribute %", Expr); |
| |
| -- Otherwise analyze and resolve all indexes |
| |
| else |
| Index := First (Expressions (Expr)); |
| Index_Typ := First_Index (P_Type); |
| while Present (Index) and then Present (Index_Typ) loop |
| Analyze_And_Resolve (Index, Etype (Index_Typ)); |
| Next (Index); |
| Next_Index (Index_Typ); |
| end loop; |
| |
| -- Detect a case where the association either lacks an |
| -- index or contains an extra index. |
| |
| if Present (Index) or else Present (Index_Typ) then |
| Error_Msg_N |
| ("dimension mismatch in index list", Assoc); |
| end if; |
| end if; |
| |
| Next (Expr); |
| end loop; |
| |
| -- The current association denotes either a single component or a |
| -- range of components of a one dimensional array: |
| |
| -- 1, 2 .. 5 |
| |
| -- Resolve the index or its high and low bounds (if range) against |
| -- the proper index type of the array. |
| |
| else |
| Index := First (Choices (Assoc)); |
| Index_Typ := First_Index (P_Type); |
| |
| if Present (Next_Index (Index_Typ)) then |
| Error_Msg_N ("too few subscripts in array reference", Assoc); |
| end if; |
| |
| while Present (Index) loop |
| |
| -- The use of others is illegal (SPARK RM 4.4.1(12)) |
| |
| if Nkind (Index) = N_Others_Choice then |
| Error_Attr |
| ("others choice not allowed in attribute %", Index); |
| |
| -- The index denotes a range of elements |
| |
| elsif Nkind (Index) = N_Range then |
| Low := Low_Bound (Index); |
| High := High_Bound (Index); |
| |
| Analyze_And_Resolve (Low, Etype (Index_Typ)); |
| Analyze_And_Resolve (High, Etype (Index_Typ)); |
| |
| -- Add a range check to ensure that the bounds of the |
| -- range are within the index type when this cannot be |
| -- determined statically. |
| |
| if not Is_OK_Static_Expression (Low) then |
| Set_Do_Range_Check (Low); |
| end if; |
| |
| if not Is_OK_Static_Expression (High) then |
| Set_Do_Range_Check (High); |
| end if; |
| |
| -- Otherwise the index denotes a single element |
| |
| else |
| Analyze_And_Resolve (Index, Etype (Index_Typ)); |
| |
| -- Add a range check to ensure that the index is within |
| -- the index type when it is not possible to determine |
| -- this statically. |
| |
| if not Is_OK_Static_Expression (Index) then |
| Set_Do_Range_Check (Index); |
| end if; |
| end if; |
| |
| Next (Index); |
| end loop; |
| end if; |
| end Analyze_Array_Component_Update; |
| |
| ------------------------------------- |
| -- Analyze_Record_Component_Update -- |
| ------------------------------------- |
| |
| procedure Analyze_Record_Component_Update (Comp : Node_Id) is |
| Comp_Name : constant Name_Id := Chars (Comp); |
| Base_Typ : Entity_Id; |
| Comp_Or_Discr : Entity_Id; |
| |
| begin |
| -- Find the discriminant or component whose name corresponds to |
| -- Comp. A simple character comparison is sufficient because all |
| -- visible names within a record type are unique. |
| |
| Comp_Or_Discr := First_Entity (P_Type); |
| while Present (Comp_Or_Discr) loop |
| if Chars (Comp_Or_Discr) = Comp_Name then |
| |
| -- Decorate the component reference by setting its entity |
| -- and type for resolution purposes. |
| |
| Set_Entity (Comp, Comp_Or_Discr); |
| Set_Etype (Comp, Etype (Comp_Or_Discr)); |
| exit; |
| end if; |
| |
| Comp_Or_Discr := Next_Entity (Comp_Or_Discr); |
| end loop; |
| |
| -- Diagnose an illegal reference |
| |
| if Present (Comp_Or_Discr) then |
| if Ekind (Comp_Or_Discr) = E_Discriminant then |
| Error_Attr |
| ("attribute % may not modify record discriminants", Comp); |
| |
| else pragma Assert (Ekind (Comp_Or_Discr) = E_Component); |
| if Contains (Comps, Comp_Or_Discr) then |
| Error_Msg_N ("component & already updated", Comp); |
| |
| -- Mark this component as processed |
| |
| else |
| Append_New_Elmt (Comp_Or_Discr, Comps); |
| end if; |
| end if; |
| |
| -- The update aggregate mentions an entity that does not belong to |
| -- the record type. |
| |
| else |
| Error_Msg_N ("& is not a component of aggregate subtype", Comp); |
| end if; |
| |
| -- Verify the consistency of types when the current component is |
| -- part of a miltiple component update. |
| |
| -- Comp_1, ..., Comp_N => <value> |
| |
| if Present (Etype (Comp)) then |
| Base_Typ := Base_Type (Etype (Comp)); |
| |
| -- Save the type of the first component reference as the |
| -- remaning references (if any) must resolve to this type. |
| |
| if No (Common_Typ) then |
| Common_Typ := Base_Typ; |
| |
| elsif Base_Typ /= Common_Typ then |
| Error_Msg_N |
| ("components in choice list must have same type", Comp); |
| end if; |
| end if; |
| end Analyze_Record_Component_Update; |
| |
| -- Local variables |
| |
| Assoc : Node_Id; |
| Comp : Node_Id; |
| |
| -- Start of processing for Update |
| |
| begin |
| Check_E1; |
| |
| if not Is_Object_Reference (P) then |
| Error_Attr_P ("prefix of attribute % must denote an object"); |
| |
| elsif not Is_Array_Type (P_Type) |
| and then not Is_Record_Type (P_Type) |
| then |
| Error_Attr_P ("prefix of attribute % must be a record or array"); |
| |
| elsif Is_Limited_View (P_Type) then |
| Error_Attr ("prefix of attribute % cannot be limited", N); |
| |
| elsif Nkind (E1) /= N_Aggregate then |
| Error_Attr ("attribute % requires component association list", N); |
| end if; |
| |
| -- Inspect the update aggregate, looking at all the associations and |
| -- choices. Perform the following checks: |
| |
| -- 1) Legality of "others" in all cases |
| -- 2) Legality of <> |
| -- 3) Component legality for arrays |
| -- 4) Component legality for records |
| |
| -- The remaining checks are performed on the expanded attribute |
| |
| Assoc := First (Component_Associations (E1)); |
| while Present (Assoc) loop |
| |
| -- The use of <> is illegal (SPARK RM 4.4.1(1)) |
| |
| if Box_Present (Assoc) then |
| Error_Attr |
| ("default initialization not allowed in attribute %", Assoc); |
| |
| -- Otherwise process the association |
| |
| else |
| Analyze (Expression (Assoc)); |
| |
| if Is_Array_Type (P_Type) then |
| Analyze_Array_Component_Update (Assoc); |
| |
| elsif Is_Record_Type (P_Type) then |
| |
| -- Reset the common type used in a multiple component update |
| -- as we are processing the contents of a new association. |
| |
| Common_Typ := Empty; |
| |
| Comp := First (Choices (Assoc)); |
| while Present (Comp) loop |
| if Nkind (Comp) = N_Identifier then |
| Analyze_Record_Component_Update (Comp); |
| |
| -- The use of others is illegal (SPARK RM 4.4.1(5)) |
| |
| elsif Nkind (Comp) = N_Others_Choice then |
| Error_Attr |
| ("others choice not allowed in attribute %", Comp); |
| |
| -- The name of a record component cannot appear in any |
| -- other form. |
| |
| else |
| Error_Msg_N |
| ("name should be identifier or OTHERS", Comp); |
| end if; |
| |
| Next (Comp); |
| end loop; |
| end if; |
| end if; |
| |
| Next (Assoc); |
| end loop; |
| |
| -- The type of attribute 'Update is that of the prefix |
| |
| Set_Etype (N, P_Type); |
| |
| Sem_Warn.Warn_On_Suspicious_Update (N); |
| end Update; |
| |
| --------- |
| -- Val -- |
| --------- |
| |
| when Attribute_Val => |
| Check_E1; |
| Check_Discrete_Type; |
| |
| if Is_Boolean_Type (P_Type) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_Name_2 := Chars (P_Type); |
| Check_SPARK_05_Restriction |
| ("attribute% is not allowed for type%", P); |
| end if; |
| |
| -- Note, we need a range check in general, but we wait for the |
| -- Resolve call to do this, since we want to let Eval_Attribute |
| -- have a chance to find an static illegality first. |
| |
| Resolve (E1, Any_Integer); |
| Set_Etype (N, P_Base_Type); |
| |
| ----------- |
| -- Valid -- |
| ----------- |
| |
| when Attribute_Valid => Valid : declare |
| Pred_Func : constant Entity_Id := Predicate_Function (P_Type); |
| |
| begin |
| Check_E0; |
| |
| -- Ignore check for object if we have a 'Valid reference generated |
| -- by the expanded code, since in some cases valid checks can occur |
| -- on items that are names, but are not objects (e.g. attributes). |
| |
| if Comes_From_Source (N) then |
| Check_Object_Reference (P); |
| |
| if not Is_Scalar_Type (P_Type) then |
| Error_Attr_P ("object for % attribute must be of scalar type"); |
| end if; |
| |
| -- If the attribute appears within the subtype's own predicate |
| -- function, then issue a warning that this will cause infinite |
| -- recursion. |
| |
| if Present (Pred_Func) and then Current_Scope = Pred_Func then |
| Error_Msg_N ("attribute Valid requires a predicate check??", N); |
| Error_Msg_N ("\and will result in infinite recursion??", N); |
| end if; |
| end if; |
| |
| Set_Etype (N, Standard_Boolean); |
| end Valid; |
| |
| ------------------- |
| -- Valid_Scalars -- |
| ------------------- |
| |
| when Attribute_Valid_Scalars => Valid_Scalars : declare |
| begin |
| Check_E0; |
| |
| if Comes_From_Source (N) then |
| Check_Object_Reference (P); |
| |
| -- Do not emit any diagnostics related to private types to avoid |
| -- disclosing the structure of the type. |
| |
| if Is_Private_Type (P_Type) then |
| |
| -- Attribute 'Valid_Scalars is not supported on private tagged |
| -- types due to a code generation issue. Is_Visible_Component |
| -- does not allow for a component of a private tagged type to |
| -- be successfully retrieved. |
| |
| -- Do not use Error_Attr_P because this bypasses any subsequent |
| -- processing and leaves the attribute with type Any_Type. This |
| -- in turn prevents the proper expansion of the attribute into |
| -- True. |
| |
| if Is_Tagged_Type (P_Type) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_N ("??effects of attribute % are ignored", N); |
| end if; |
| |
| -- Otherwise the type is not private |
| |
| else |
| if not Scalar_Part_Present (P_Type) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_F |
| ("??attribute % always True, no scalars to check", P); |
| Set_Boolean_Result (N, True); |
| end if; |
| |
| -- Attribute 'Valid_Scalars is illegal on unchecked union types |
| -- because it is not always guaranteed that the components are |
| -- retrievable based on whether the discriminants are inferable |
| |
| if Has_Unchecked_Union (P_Type) then |
| Error_Attr_P |
| ("attribute % not allowed for Unchecked_Union type"); |
| end if; |
| end if; |
| end if; |
| |
| Set_Etype (N, Standard_Boolean); |
| end Valid_Scalars; |
| |
| ----------- |
| -- Value -- |
| ----------- |
| |
| when Attribute_Value => |
| Check_SPARK_05_Restriction_On_Attribute; |
| Check_E1; |
| Check_Scalar_Type; |
| |
| -- Case of enumeration type |
| |
| -- When an enumeration type appears in an attribute reference, all |
| -- literals of the type are marked as referenced. This must only be |
| -- done if the attribute reference appears in the current source. |
| -- Otherwise the information on references may differ between a |
| -- normal compilation and one that performs inlining. |
| |
| if Is_Enumeration_Type (P_Type) |
| and then In_Extended_Main_Code_Unit (N) |
| then |
| Check_Restriction (No_Enumeration_Maps, N); |
| |
| -- Mark all enumeration literals as referenced, since the use of |
| -- the Value attribute can implicitly reference any of the |
| -- literals of the enumeration base type. |
| |
| declare |
| Ent : Entity_Id := First_Literal (P_Base_Type); |
| begin |
| while Present (Ent) loop |
| Set_Referenced (Ent); |
| Next_Literal (Ent); |
| end loop; |
| end; |
| end if; |
| |
| -- Set Etype before resolving expression because expansion of |
| -- expression may require enclosing type. Note that the type |
| -- returned by 'Value is the base type of the prefix type. |
| |
| Set_Etype (N, P_Base_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| |
| -- Check restriction No_Fixed_IO |
| |
| if Restriction_Check_Required (No_Fixed_IO) |
| and then Is_Fixed_Point_Type (P_Type) |
| then |
| Check_Restriction (No_Fixed_IO, P); |
| end if; |
| |
| ---------------- |
| -- Value_Size -- |
| ---------------- |
| |
| when Attribute_Value_Size => |
| Check_E0; |
| Check_Type; |
| Check_Not_Incomplete_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ------------- |
| -- Version -- |
| ------------- |
| |
| when Attribute_Version => |
| Check_E0; |
| Check_Program_Unit; |
| Set_Etype (N, RTE (RE_Version_String)); |
| |
| ------------------ |
| -- Wchar_T_Size -- |
| ------------------ |
| |
| when Attribute_Wchar_T_Size => |
| Standard_Attribute (Interfaces_Wchar_T_Size); |
| |
| ---------------- |
| -- Wide_Image -- |
| ---------------- |
| |
| when Attribute_Wide_Image => |
| Analyze_Image_Attribute (Standard_Wide_String); |
| |
| --------------------- |
| -- Wide_Wide_Image -- |
| --------------------- |
| |
| when Attribute_Wide_Wide_Image => |
| Analyze_Image_Attribute (Standard_Wide_Wide_String); |
| |
| ---------------- |
| -- Wide_Value -- |
| ---------------- |
| |
| when Attribute_Wide_Value => |
| Check_SPARK_05_Restriction_On_Attribute; |
| Check_E1; |
| Check_Scalar_Type; |
| |
| -- Set Etype before resolving expression because expansion |
| -- of expression may require enclosing type. |
| |
| Set_Etype (N, P_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| |
| -- Check restriction No_Fixed_IO |
| |
| if Restriction_Check_Required (No_Fixed_IO) |
| and then Is_Fixed_Point_Type (P_Type) |
| then |
| Check_Restriction (No_Fixed_IO, P); |
| end if; |
| |
| --------------------- |
| -- Wide_Wide_Value -- |
| --------------------- |
| |
| when Attribute_Wide_Wide_Value => |
| Check_E1; |
| Check_Scalar_Type; |
| |
| -- Set Etype before resolving expression because expansion |
| -- of expression may require enclosing type. |
| |
| Set_Etype (N, P_Type); |
| Validate_Non_Static_Attribute_Function_Call; |
| |
| -- Check restriction No_Fixed_IO |
| |
| if Restriction_Check_Required (No_Fixed_IO) |
| and then Is_Fixed_Point_Type (P_Type) |
| then |
| Check_Restriction (No_Fixed_IO, P); |
| end if; |
| |
| --------------------- |
| -- Wide_Wide_Width -- |
| --------------------- |
| |
| when Attribute_Wide_Wide_Width => |
| Check_E0; |
| Check_Scalar_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ---------------- |
| -- Wide_Width -- |
| ---------------- |
| |
| when Attribute_Wide_Width => |
| Check_SPARK_05_Restriction_On_Attribute; |
| Check_E0; |
| Check_Scalar_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| ----------- |
| -- Width -- |
| ----------- |
| |
| when Attribute_Width => |
| Check_SPARK_05_Restriction_On_Attribute; |
| Check_E0; |
| Check_Scalar_Type; |
| Set_Etype (N, Universal_Integer); |
| |
| --------------- |
| -- Word_Size -- |
| --------------- |
| |
| when Attribute_Word_Size => |
| Standard_Attribute (System_Word_Size); |
| |
| ----------- |
| -- Write -- |
| ----------- |
| |
| when Attribute_Write => |
| Check_E2; |
| Check_Stream_Attribute (TSS_Stream_Write); |
| Set_Etype (N, Standard_Void_Type); |
| Resolve (N, Standard_Void_Type); |
| |
| end case; |
| |
| -- In SPARK certain attributes (see below) depend on Tasking_State. |
| -- Ensure that the entity is available for gnat2why by loading it. |
| -- See SPARK RM 9(18) for the relevant rule. |
| |
| if GNATprove_Mode then |
| declare |
| Unused : Entity_Id; |
| |
| begin |
| case Attr_Id is |
| when Attribute_Callable |
| | Attribute_Caller |
| | Attribute_Count |
| | Attribute_Terminated |
| => |
| Unused := RTE (RE_Tasking_State); |
| |
| when others => |
| null; |
| end case; |
| end; |
| end if; |
| |
| -- All errors raise Bad_Attribute, so that we get out before any further |
| -- damage occurs when an error is detected (for example, if we check for |
| -- one attribute expression, and the check succeeds, we want to be able |
| -- to proceed securely assuming that an expression is in fact present. |
| |
| -- Note: we set the attribute analyzed in this case to prevent any |
| -- attempt at reanalysis which could generate spurious error msgs. |
| |
| exception |
| when Bad_Attribute => |
| Set_Analyzed (N); |
| Set_Etype (N, Any_Type); |
| return; |
| end Analyze_Attribute; |
| |
| -------------------- |
| -- Eval_Attribute -- |
| -------------------- |
| |
| procedure Eval_Attribute (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Aname : constant Name_Id := Attribute_Name (N); |
| Id : constant Attribute_Id := Get_Attribute_Id (Aname); |
| P : constant Node_Id := Prefix (N); |
| |
| C_Type : constant Entity_Id := Etype (N); |
| -- The type imposed by the context |
| |
| E1 : Node_Id; |
| -- First expression, or Empty if none |
| |
| E2 : Node_Id; |
| -- Second expression, or Empty if none |
| |
| P_Entity : Entity_Id; |
| -- Entity denoted by prefix |
| |
| P_Type : Entity_Id; |
| -- The type of the prefix |
| |
| P_Base_Type : Entity_Id; |
| -- The base type of the prefix type |
| |
| P_Root_Type : Entity_Id; |
| -- The root type of the prefix type |
| |
| Static : Boolean; |
| -- True if the result is Static. This is set by the general processing |
| -- to true if the prefix is static, and all expressions are static. It |
| -- can be reset as processing continues for particular attributes. This |
| -- flag can still be True if the reference raises a constraint error. |
| -- Is_Static_Expression (N) is set to follow this value as it is set |
| -- and we could always reference this, but it is convenient to have a |
| -- simple short name to use, since it is frequently referenced. |
| |
| Lo_Bound, Hi_Bound : Node_Id; |
| -- Expressions for low and high bounds of type or array index referenced |
| -- by First, Last, or Length attribute for array, set by Set_Bounds. |
| |
| CE_Node : Node_Id; |
| -- Constraint error node used if we have an attribute reference has |
| -- an argument that raises a constraint error. In this case we replace |
| -- the attribute with a raise constraint_error node. This is important |
| -- processing, since otherwise gigi might see an attribute which it is |
| -- unprepared to deal with. |
| |
| procedure Check_Concurrent_Discriminant (Bound : Node_Id); |
| -- If Bound is a reference to a discriminant of a task or protected type |
| -- occurring within the object's body, rewrite attribute reference into |
| -- a reference to the corresponding discriminal. Use for the expansion |
| -- of checks against bounds of entry family index subtypes. |
| |
| procedure Check_Expressions; |
| -- In case where the attribute is not foldable, the expressions, if |
| -- any, of the attribute, are in a non-static context. This procedure |
| -- performs the required additional checks. |
| |
| function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean; |
| -- Determines if the given type has compile time known bounds. Note |
| -- that we enter the case statement even in cases where the prefix |
| -- type does NOT have known bounds, so it is important to guard any |
| -- attempt to evaluate both bounds with a call to this function. |
| |
| procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint); |
| -- This procedure is called when the attribute N has a non-static |
| -- but compile time known value given by Val. It includes the |
| -- necessary checks for out of range values. |
| |
| function Fore_Value return Nat; |
| -- Computes the Fore value for the current attribute prefix, which is |
| -- known to be a static fixed-point type. Used by Fore and Width. |
| |
| function Mantissa return Uint; |
| -- Returns the Mantissa value for the prefix type |
| |
| procedure Set_Bounds; |
| -- Used for First, Last and Length attributes applied to an array or |
| -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low |
| -- and high bound expressions for the index referenced by the attribute |
| -- designator (i.e. the first index if no expression is present, and the |
| -- N'th index if the value N is present as an expression). Also used for |
| -- First and Last of scalar types and for First_Valid and Last_Valid. |
| -- Static is reset to False if the type or index type is not statically |
| -- constrained. |
| |
| function Statically_Denotes_Entity (N : Node_Id) return Boolean; |
| -- Verify that the prefix of a potentially static array attribute |
| -- satisfies the conditions of 4.9 (14). |
| |
| ----------------------------------- |
| -- Check_Concurrent_Discriminant -- |
| ----------------------------------- |
| |
| procedure Check_Concurrent_Discriminant (Bound : Node_Id) is |
| Tsk : Entity_Id; |
| -- The concurrent (task or protected) type |
| |
| begin |
| if Nkind (Bound) = N_Identifier |
| and then Ekind (Entity (Bound)) = E_Discriminant |
| and then Is_Concurrent_Record_Type (Scope (Entity (Bound))) |
| then |
| Tsk := Corresponding_Concurrent_Type (Scope (Entity (Bound))); |
| |
| if In_Open_Scopes (Tsk) and then Has_Completion (Tsk) then |
| |
| -- Find discriminant of original concurrent type, and use |
| -- its current discriminal, which is the renaming within |
| -- the task/protected body. |
| |
| Rewrite (N, |
| New_Occurrence_Of |
| (Find_Body_Discriminal (Entity (Bound)), Loc)); |
| end if; |
| end if; |
| end Check_Concurrent_Discriminant; |
| |
| ----------------------- |
| -- Check_Expressions -- |
| ----------------------- |
| |
| procedure Check_Expressions is |
| E : Node_Id; |
| begin |
| E := E1; |
| while Present (E) loop |
| Check_Non_Static_Context (E); |
| Next (E); |
| end loop; |
| end Check_Expressions; |
| |
| ---------------------------------- |
| -- Compile_Time_Known_Attribute -- |
| ---------------------------------- |
| |
| procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is |
| T : constant Entity_Id := Etype (N); |
| |
| begin |
| Fold_Uint (N, Val, False); |
| |
| -- Check that result is in bounds of the type if it is static |
| |
| if Is_In_Range (N, T, Assume_Valid => False) then |
| null; |
| |
| elsif Is_Out_Of_Range (N, T) then |
| Apply_Compile_Time_Constraint_Error |
| (N, "value not in range of}??", CE_Range_Check_Failed); |
| |
| elsif not Range_Checks_Suppressed (T) then |
| Enable_Range_Check (N); |
| |
| else |
| Set_Do_Range_Check (N, False); |
| end if; |
| end Compile_Time_Known_Attribute; |
| |
| ------------------------------- |
| -- Compile_Time_Known_Bounds -- |
| ------------------------------- |
| |
| function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is |
| begin |
| return |
| Compile_Time_Known_Value (Type_Low_Bound (Typ)) |
| and then |
| Compile_Time_Known_Value (Type_High_Bound (Typ)); |
| end Compile_Time_Known_Bounds; |
| |
| ---------------- |
| -- Fore_Value -- |
| ---------------- |
| |
| -- Note that the Fore calculation is based on the actual values |
| -- of the bounds, and does not take into account possible rounding. |
| |
| function Fore_Value return Nat is |
| Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type)); |
| Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type)); |
| Small : constant Ureal := Small_Value (P_Type); |
| Lo_Real : constant Ureal := Lo * Small; |
| Hi_Real : constant Ureal := Hi * Small; |
| T : Ureal; |
| R : Nat; |
| |
| begin |
| -- Bounds are given in terms of small units, so first compute |
| -- proper values as reals. |
| |
| T := UR_Max (abs Lo_Real, abs Hi_Real); |
| R := 2; |
| |
| -- Loop to compute proper value if more than one digit required |
| |
| while T >= Ureal_10 loop |
| R := R + 1; |
| T := T / Ureal_10; |
| end loop; |
| |
| return R; |
| end Fore_Value; |
| |
| -------------- |
| -- Mantissa -- |
| -------------- |
| |
| -- Table of mantissa values accessed by function Computed using |
| -- the relation: |
| |
| -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1) |
| |
| -- where D is T'Digits (RM83 3.5.7) |
| |
| Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := ( |
| 1 => 5, |
| 2 => 8, |
| 3 => 11, |
| 4 => 15, |
| 5 => 18, |
| 6 => 21, |
| 7 => 25, |
| 8 => 28, |
| 9 => 31, |
| 10 => 35, |
| 11 => 38, |
| 12 => 41, |
| 13 => 45, |
| 14 => 48, |
| 15 => 51, |
| 16 => 55, |
| 17 => 58, |
| 18 => 61, |
| 19 => 65, |
| 20 => 68, |
| 21 => 71, |
| 22 => 75, |
| 23 => 78, |
| 24 => 81, |
| 25 => 85, |
| 26 => 88, |
| 27 => 91, |
| 28 => 95, |
| 29 => 98, |
| 30 => 101, |
| 31 => 104, |
| 32 => 108, |
| 33 => 111, |
| 34 => 114, |
| 35 => 118, |
| 36 => 121, |
| 37 => 124, |
| 38 => 128, |
| 39 => 131, |
| 40 => 134); |
| |
| function Mantissa return Uint is |
| begin |
| return |
| UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type)))); |
| end Mantissa; |
| |
| ---------------- |
| -- Set_Bounds -- |
| ---------------- |
| |
| procedure Set_Bounds is |
| Ndim : Nat; |
| Indx : Node_Id; |
| Ityp : Entity_Id; |
| |
| begin |
| -- For a string literal subtype, we have to construct the bounds. |
| -- Valid Ada code never applies attributes to string literals, but |
| -- it is convenient to allow the expander to generate attribute |
| -- references of this type (e.g. First and Last applied to a string |
| -- literal). |
| |
| -- Note that the whole point of the E_String_Literal_Subtype is to |
| -- avoid this construction of bounds, but the cases in which we |
| -- have to materialize them are rare enough that we don't worry. |
| |
| -- The low bound is simply the low bound of the base type. The |
| -- high bound is computed from the length of the string and this |
| -- low bound. |
| |
| if Ekind (P_Type) = E_String_Literal_Subtype then |
| Ityp := Etype (First_Index (Base_Type (P_Type))); |
| Lo_Bound := Type_Low_Bound (Ityp); |
| |
| Hi_Bound := |
| Make_Integer_Literal (Sloc (P), |
| Intval => |
| Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1); |
| |
| Set_Parent (Hi_Bound, P); |
| Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound)); |
| return; |
| |
| -- For non-array case, just get bounds of scalar type |
| |
| elsif Is_Scalar_Type (P_Type) then |
| Ityp := P_Type; |
| |
| -- For a fixed-point type, we must freeze to get the attributes |
| -- of the fixed-point type set now so we can reference them. |
| |
| if Is_Fixed_Point_Type (P_Type) |
| and then not Is_Frozen (Base_Type (P_Type)) |
| and then Compile_Time_Known_Value (Type_Low_Bound (P_Type)) |
| and then Compile_Time_Known_Value (Type_High_Bound (P_Type)) |
| then |
| Freeze_Fixed_Point_Type (Base_Type (P_Type)); |
| end if; |
| |
| -- For array case, get type of proper index |
| |
| else |
| if No (E1) then |
| Ndim := 1; |
| else |
| Ndim := UI_To_Int (Expr_Value (E1)); |
| end if; |
| |
| Indx := First_Index (P_Type); |
| for J in 1 .. Ndim - 1 loop |
| Next_Index (Indx); |
| end loop; |
| |
| -- If no index type, get out (some other error occurred, and |
| -- we don't have enough information to complete the job). |
| |
| if No (Indx) then |
| Lo_Bound := Error; |
| Hi_Bound := Error; |
| return; |
| end if; |
| |
| Ityp := Etype (Indx); |
| end if; |
| |
| -- A discrete range in an index constraint is allowed to be a |
| -- subtype indication. This is syntactically a pain, but should |
| -- not propagate to the entity for the corresponding index subtype. |
| -- After checking that the subtype indication is legal, the range |
| -- of the subtype indication should be transfered to the entity. |
| -- The attributes for the bounds should remain the simple retrievals |
| -- that they are now. |
| |
| Lo_Bound := Type_Low_Bound (Ityp); |
| Hi_Bound := Type_High_Bound (Ityp); |
| |
| -- If subtype is non-static, result is definitely non-static |
| |
| if not Is_Static_Subtype (Ityp) then |
| Static := False; |
| Set_Is_Static_Expression (N, False); |
| |
| -- Subtype is static, does it raise CE? |
| |
| elsif not Is_OK_Static_Subtype (Ityp) then |
| Set_Raises_Constraint_Error (N); |
| end if; |
| end Set_Bounds; |
| |
| ------------------------------- |
| -- Statically_Denotes_Entity -- |
| ------------------------------- |
| |
| function Statically_Denotes_Entity (N : Node_Id) return Boolean is |
| E : Entity_Id; |
| |
| begin |
| if not Is_Entity_Name (N) then |
| return False; |
| else |
| E := Entity (N); |
| end if; |
| |
| return |
| Nkind (Parent (E)) /= N_Object_Renaming_Declaration |
| or else Statically_Denotes_Entity (Renamed_Object (E)); |
| end Statically_Denotes_Entity; |
| |
| -- Start of processing for Eval_Attribute |
| |
| begin |
| -- Initialize result as non-static, will be reset if appropriate |
| |
| Set_Is_Static_Expression (N, False); |
| Static := False; |
| |
| -- Acquire first two expressions (at the moment, no attributes take more |
| -- than two expressions in any case). |
| |
| if Present (Expressions (N)) then |
| E1 := First (Expressions (N)); |
| E2 := Next (E1); |
| else |
| E1 := Empty; |
| E2 := Empty; |
| end if; |
| |
| -- Special processing for Enabled attribute. This attribute has a very |
| -- special prefix, and the easiest way to avoid lots of special checks |
| -- to protect this special prefix from causing trouble is to deal with |
| -- this attribute immediately and be done with it. |
| |
| if Id = Attribute_Enabled then |
| |
| -- We skip evaluation if the expander is not active. This is not just |
| -- an optimization. It is of key importance that we not rewrite the |
| -- attribute in a generic template, since we want to pick up the |
| -- setting of the check in the instance, Testing Expander_Active |
| -- might seem an easy way of doing this, but we need to account for |
| -- ASIS needs, so check explicitly for a generic context. |
| |
| if not Inside_A_Generic then |
| declare |
| C : constant Check_Id := Get_Check_Id (Chars (P)); |
| R : Boolean; |
| |
| begin |
| if No (E1) then |
| if C in Predefined_Check_Id then |
| R := Scope_Suppress.Suppress (C); |
| else |
| R := Is_Check_Suppressed (Empty, C); |
| end if; |
| |
| else |
| R := Is_Check_Suppressed (Entity (E1), C); |
| end if; |
| |
| Rewrite (N, New_Occurrence_Of (Boolean_Literals (not R), Loc)); |
| end; |
| end if; |
| |
| return; |
| end if; |
| |
| -- Attribute 'Img applied to a static enumeration value is static, and |
| -- we will do the folding right here (things get confused if we let this |
| -- case go through the normal circuitry). |
| |
| if Attribute_Name (N) = Name_Img |
| and then Is_Entity_Name (P) |
| and then Is_Enumeration_Type (Etype (Entity (P))) |
| and then Is_OK_Static_Expression (P) |
| then |
| declare |
| Lit : constant Entity_Id := Expr_Value_E (P); |
| Str : String_Id; |
| |
| begin |
| Start_String; |
| Get_Unqualified_Decoded_Name_String (Chars (Lit)); |
| Set_Casing (All_Upper_Case); |
| Store_String_Chars (Name_Buffer (1 .. Name_Len)); |
| Str := End_String; |
| |
| Rewrite (N, Make_String_Literal (Loc, Strval => Str)); |
| Analyze_And_Resolve (N, Standard_String); |
| Set_Is_Static_Expression (N, True); |
| end; |
| |
| return; |
| end if; |
| |
| -- Special processing for cases where the prefix is an object. For this |
| -- purpose, a string literal counts as an object (attributes of string |
| -- literals can only appear in generated code). |
| |
| if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then |
| |
| -- For Component_Size, the prefix is an array object, and we apply |
| -- the attribute to the type of the object. This is allowed for both |
| -- unconstrained and constrained arrays, since the bounds have no |
| -- influence on the value of this attribute. |
| |
| if Id = Attribute_Component_Size then |
| P_Entity := Etype (P); |
| |
| -- For Enum_Rep, evaluation depends on the nature of the prefix and |
| -- the optional argument. |
| |
| elsif Id = Attribute_Enum_Rep then |
| if Is_Entity_Name (P) then |
| |
| declare |
| Enum_Expr : Node_Id; |
| -- The enumeration-type expression of interest |
| |
| begin |
| -- P'Enum_Rep case |
| |
| if Ekind_In (Entity (P), E_Constant, |
| E_Enumeration_Literal) |
| then |
| Enum_Expr := P; |
| |
| -- Enum_Type'Enum_Rep (E1) case |
| |
| elsif Is_Enumeration_Type (Entity (P)) then |
| Enum_Expr := E1; |
| |
| -- Otherwise the attribute must be expanded into a |
| -- conversion and evaluated at run time. |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- We can fold if the expression is an enumeration |
| -- literal, or if it denotes a constant whose value |
| -- is known at compile time. |
| |
| if Nkind (Enum_Expr) in N_Has_Entity |
| and then (Ekind (Entity (Enum_Expr)) = |
| E_Enumeration_Literal |
| or else |
| (Ekind (Entity (Enum_Expr)) = E_Constant |
| and then Nkind (Parent (Entity (Enum_Expr))) = |
| N_Object_Declaration |
| and then Compile_Time_Known_Value |
| (Expression (Parent (Entity (P)))))) |
| then |
| P_Entity := Etype (P); |
| else |
| Check_Expressions; |
| return; |
| end if; |
| end; |
| |
| -- Otherwise the attribute is illegal, do not attempt to perform |
| -- any kind of folding. |
| |
| else |
| return; |
| end if; |
| |
| -- For First and Last, the prefix is an array object, and we apply |
| -- the attribute to the type of the array, but we need a constrained |
| -- type for this, so we use the actual subtype if available. |
| |
| elsif Id = Attribute_First or else |
| Id = Attribute_Last or else |
| Id = Attribute_Length |
| then |
| declare |
| AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P); |
| |
| begin |
| if Present (AS) and then Is_Constrained (AS) then |
| P_Entity := AS; |
| |
| -- If we have an unconstrained type we cannot fold |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| end; |
| |
| -- For Size, give size of object if available, otherwise we |
| -- cannot fold Size. |
| |
| elsif Id = Attribute_Size then |
| if Is_Entity_Name (P) |
| and then Known_Esize (Entity (P)) |
| then |
| Compile_Time_Known_Attribute (N, Esize (Entity (P))); |
| return; |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- For Alignment, give size of object if available, otherwise we |
| -- cannot fold Alignment. |
| |
| elsif Id = Attribute_Alignment then |
| if Is_Entity_Name (P) |
| and then Known_Alignment (Entity (P)) |
| then |
| Fold_Uint (N, Alignment (Entity (P)), Static); |
| return; |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- For Lock_Free, we apply the attribute to the type of the object. |
| -- This is allowed since we have already verified that the type is a |
| -- protected type. |
| |
| elsif Id = Attribute_Lock_Free then |
| P_Entity := Etype (P); |
| |
| -- No other attributes for objects are folded |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- Cases where P is not an object. Cannot do anything if P is not the |
| -- name of an entity. |
| |
| elsif not Is_Entity_Name (P) then |
| Check_Expressions; |
| return; |
| |
| -- Otherwise get prefix entity |
| |
| else |
| P_Entity := Entity (P); |
| end if; |
| |
| -- If we are asked to evaluate an attribute where the prefix is a |
| -- non-frozen generic actual type whose RM_Size is still set to zero, |
| -- then abandon the effort. |
| |
| if Is_Type (P_Entity) |
| and then (not Is_Frozen (P_Entity) |
| and then Is_Generic_Actual_Type (P_Entity) |
| and then RM_Size (P_Entity) = 0) |
| |
| -- However, the attribute Unconstrained_Array must be evaluated, |
| -- since it is documented to be a static attribute (and can for |
| -- example appear in a Compile_Time_Warning pragma). The frozen |
| -- status of the type does not affect its evaluation. |
| |
| and then Id /= Attribute_Unconstrained_Array |
| then |
| return; |
| end if; |
| |
| -- At this stage P_Entity is the entity to which the attribute |
| -- is to be applied. This is usually simply the entity of the |
| -- prefix, except in some cases of attributes for objects, where |
| -- as described above, we apply the attribute to the object type. |
| |
| -- Here is where we make sure that static attributes are properly |
| -- marked as such. These are attributes whose prefix is a static |
| -- scalar subtype, whose result is scalar, and whose arguments, if |
| -- present, are static scalar expressions. Note that such references |
| -- are static expressions even if they raise Constraint_Error. |
| |
| -- For example, Boolean'Pos (1/0 = 0) is a static expression, even |
| -- though evaluating it raises constraint error. This means that a |
| -- declaration like: |
| |
| -- X : constant := (if True then 1 else Boolean'Pos (1/0 = 0)); |
| |
| -- is legal, since here this expression appears in a statically |
| -- unevaluated position, so it does not actually raise an exception. |
| |
| if Is_Scalar_Type (P_Entity) |
| and then (not Is_Generic_Type (P_Entity)) |
| and then Is_Static_Subtype (P_Entity) |
| and then Is_Scalar_Type (Etype (N)) |
| and then |
| (No (E1) |
| or else (Is_Static_Expression (E1) |
| and then Is_Scalar_Type (Etype (E1)))) |
| and then |
| (No (E2) |
| or else (Is_Static_Expression (E2) |
| and then Is_Scalar_Type (Etype (E1)))) |
| then |
| Static := True; |
| Set_Is_Static_Expression (N, True); |
| end if; |
| |
| -- First foldable possibility is a scalar or array type (RM 4.9(7)) |
| -- that is not generic (generic types are eliminated by RM 4.9(25)). |
| -- Note we allow non-static non-generic types at this stage as further |
| -- described below. |
| |
| if Is_Type (P_Entity) |
| and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity)) |
| and then (not Is_Generic_Type (P_Entity)) |
| then |
| P_Type := P_Entity; |
| |
| -- Second foldable possibility is an array object (RM 4.9(8)) |
| |
| elsif Ekind_In (P_Entity, E_Variable, E_Constant) |
| and then Is_Array_Type (Etype (P_Entity)) |
| and then (not Is_Generic_Type (Etype (P_Entity))) |
| then |
| P_Type := Etype (P_Entity); |
| |
| -- If the entity is an array constant with an unconstrained nominal |
| -- subtype then get the type from the initial value. If the value has |
| -- been expanded into assignments, there is no expression and the |
| -- attribute reference remains dynamic. |
| |
| -- We could do better here and retrieve the type ??? |
| |
| if Ekind (P_Entity) = E_Constant |
| and then not Is_Constrained (P_Type) |
| then |
| if No (Constant_Value (P_Entity)) then |
| return; |
| else |
| P_Type := Etype (Constant_Value (P_Entity)); |
| end if; |
| end if; |
| |
| -- Definite must be folded if the prefix is not a generic type, that |
| -- is to say if we are within an instantiation. Same processing applies |
| -- to the GNAT attributes Atomic_Always_Lock_Free, Has_Discriminants, |
| -- Lock_Free, Type_Class, Has_Tagged_Value, and Unconstrained_Array. |
| |
| elsif (Id = Attribute_Atomic_Always_Lock_Free or else |
| Id = Attribute_Definite or else |
| Id = Attribute_Has_Access_Values or else |
| Id = Attribute_Has_Discriminants or else |
| Id = Attribute_Has_Tagged_Values or else |
| Id = Attribute_Lock_Free or else |
| Id = Attribute_Type_Class or else |
| Id = Attribute_Unconstrained_Array or else |
| Id = Attribute_Max_Alignment_For_Allocation) |
| and then not Is_Generic_Type (P_Entity) |
| then |
| P_Type := P_Entity; |
| |
| -- We can fold 'Size applied to a type if the size is known (as happens |
| -- for a size from an attribute definition clause). At this stage, this |
| -- can happen only for types (e.g. record types) for which the size is |
| -- always non-static. We exclude generic types from consideration (since |
| -- they have bogus sizes set within templates). |
| |
| elsif Id = Attribute_Size |
| and then Is_Type (P_Entity) |
| and then (not Is_Generic_Type (P_Entity)) |
| and then Known_Static_RM_Size (P_Entity) |
| then |
| Compile_Time_Known_Attribute (N, RM_Size (P_Entity)); |
| return; |
| |
| -- We can fold 'Alignment applied to a type if the alignment is known |
| -- (as happens for an alignment from an attribute definition clause). |
| -- At this stage, this can happen only for types (e.g. record types) for |
| -- which the size is always non-static. We exclude generic types from |
| -- consideration (since they have bogus sizes set within templates). |
| |
| elsif Id = Attribute_Alignment |
| and then Is_Type (P_Entity) |
| and then (not Is_Generic_Type (P_Entity)) |
| and then Known_Alignment (P_Entity) |
| then |
| Compile_Time_Known_Attribute (N, Alignment (P_Entity)); |
| return; |
| |
| -- If this is an access attribute that is known to fail accessibility |
| -- check, rewrite accordingly. |
| |
| elsif Attribute_Name (N) = Name_Access |
| and then Raises_Constraint_Error (N) |
| then |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, C_Type); |
| return; |
| |
| -- No other cases are foldable (they certainly aren't static, and at |
| -- the moment we don't try to fold any cases other than the ones above). |
| |
| else |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- If either attribute or the prefix is Any_Type, then propagate |
| -- Any_Type to the result and don't do anything else at all. |
| |
| if P_Type = Any_Type |
| or else (Present (E1) and then Etype (E1) = Any_Type) |
| or else (Present (E2) and then Etype (E2) = Any_Type) |
| then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- Scalar subtype case. We have not yet enforced the static requirement |
| -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases |
| -- of non-static attribute references (e.g. S'Digits for a non-static |
| -- floating-point type, which we can compute at compile time). |
| |
| -- Note: this folding of non-static attributes is not simply a case of |
| -- optimization. For many of the attributes affected, Gigi cannot handle |
| -- the attribute and depends on the front end having folded them away. |
| |
| -- Note: although we don't require staticness at this stage, we do set |
| -- the Static variable to record the staticness, for easy reference by |
| -- those attributes where it matters (e.g. Succ and Pred), and also to |
| -- be used to ensure that non-static folded things are not marked as |
| -- being static (a check that is done right at the end). |
| |
| P_Root_Type := Root_Type (P_Type); |
| P_Base_Type := Base_Type (P_Type); |
| |
| -- If the root type or base type is generic, then we cannot fold. This |
| -- test is needed because subtypes of generic types are not always |
| -- marked as being generic themselves (which seems odd???) |
| |
| if Is_Generic_Type (P_Root_Type) |
| or else Is_Generic_Type (P_Base_Type) |
| then |
| return; |
| end if; |
| |
| if Is_Scalar_Type (P_Type) then |
| if not Is_Static_Subtype (P_Type) then |
| Static := False; |
| Set_Is_Static_Expression (N, False); |
| elsif not Is_OK_Static_Subtype (P_Type) then |
| Set_Raises_Constraint_Error (N); |
| end if; |
| |
| -- Array case. We enforce the constrained requirement of (RM 4.9(7-8)) |
| -- since we can't do anything with unconstrained arrays. In addition, |
| -- only the First, Last and Length attributes are possibly static. |
| |
| -- Atomic_Always_Lock_Free, Definite, Has_Access_Values, |
| -- Has_Discriminants, Has_Tagged_Values, Lock_Free, Type_Class, and |
| -- Unconstrained_Array are again exceptions, because they apply as well |
| -- to unconstrained types. |
| |
| -- In addition Component_Size is an exception since it is possibly |
| -- foldable, even though it is never static, and it does apply to |
| -- unconstrained arrays. Furthermore, it is essential to fold this |
| -- in the packed case, since otherwise the value will be incorrect. |
| |
| elsif Id = Attribute_Atomic_Always_Lock_Free or else |
| Id = Attribute_Definite or else |
| Id = Attribute_Has_Access_Values or else |
| Id = Attribute_Has_Discriminants or else |
| Id = Attribute_Has_Tagged_Values or else |
| Id = Attribute_Lock_Free or else |
| Id = Attribute_Type_Class or else |
| Id = Attribute_Unconstrained_Array or else |
| Id = Attribute_Component_Size |
| then |
| Static := False; |
| Set_Is_Static_Expression (N, False); |
| |
| elsif Id /= Attribute_Max_Alignment_For_Allocation then |
| if not Is_Constrained (P_Type) |
| or else (Id /= Attribute_First and then |
| Id /= Attribute_Last and then |
| Id /= Attribute_Length) |
| then |
| Check_Expressions; |
| return; |
| end if; |
| |
| -- The rules in (RM 4.9(7,8)) require a static array, but as in the |
| -- scalar case, we hold off on enforcing staticness, since there are |
| -- cases which we can fold at compile time even though they are not |
| -- static (e.g. 'Length applied to a static index, even though other |
| -- non-static indexes make the array type non-static). This is only |
| -- an optimization, but it falls out essentially free, so why not. |
| -- Again we compute the variable Static for easy reference later |
| -- (note that no array attributes are static in Ada 83). |
| |
| -- We also need to set Static properly for subsequent legality checks |
| -- which might otherwise accept non-static constants in contexts |
| -- where they are not legal. |
| |
| Static := |
| Ada_Version >= Ada_95 and then Statically_Denotes_Entity (P); |
| Set_Is_Static_Expression (N, Static); |
| |
| declare |
| Nod : Node_Id; |
| |
| begin |
| Nod := First_Index (P_Type); |
| |
| -- The expression is static if the array type is constrained |
| -- by given bounds, and not by an initial expression. Constant |
| -- strings are static in any case. |
| |
| if Root_Type (P_Type) /= Standard_String then |
| Static := |
| Static and then not Is_Constr_Subt_For_U_Nominal (P_Type); |
| Set_Is_Static_Expression (N, Static); |
| end if; |
| |
| while Present (Nod) loop |
| if not Is_Static_Subtype (Etype (Nod)) then |
| Static := False; |
| Set_Is_Static_Expression (N, False); |
| |
| elsif not Is_OK_Static_Subtype (Etype (Nod)) then |
| Set_Raises_Constraint_Error (N); |
| Static := False; |
| Set_Is_Static_Expression (N, False); |
| end if; |
| |
| -- If however the index type is generic, or derived from |
| -- one, attributes cannot be folded. |
| |
| if Is_Generic_Type (Root_Type (Etype (Nod))) |
| and then Id /= Attribute_Component_Size |
| then |
| return; |
| end if; |
| |
| Next_Index (Nod); |
| end loop; |
| end; |
| end if; |
| |
| -- Check any expressions that are present. Note that these expressions, |
| -- depending on the particular attribute type, are either part of the |
| -- attribute designator, or they are arguments in a case where the |
| -- attribute reference returns a function. In the latter case, the |
| -- rule in (RM 4.9(22)) applies and in particular requires the type |
| -- of the expressions to be scalar in order for the attribute to be |
| -- considered to be static. |
| |
| declare |
| E : Node_Id; |
| |
| begin |
| E := E1; |
| |
| while Present (E) loop |
| |
| -- If expression is not static, then the attribute reference |
| -- result certainly cannot be static. |
| |
| if not Is_Static_Expression (E) then |
| Static := False; |
| Set_Is_Static_Expression (N, False); |
| end if; |
| |
| if Raises_Constraint_Error (E) then |
| Set_Raises_Constraint_Error (N); |
| end if; |
| |
| -- If the result is not known at compile time, or is not of |
| -- a scalar type, then the result is definitely not static, |
| -- so we can quit now. |
| |
| if not Compile_Time_Known_Value (E) |
| or else not Is_Scalar_Type (Etype (E)) |
| then |
| -- An odd special case, if this is a Pos attribute, this |
| -- is where we need to apply a range check since it does |
| -- not get done anywhere else. |
| |
| if Id = Attribute_Pos then |
| if Is_Integer_Type (Etype (E)) then |
| Apply_Range_Check (E, Etype (N)); |
| end if; |
| end if; |
| |
| Check_Expressions; |
| return; |
| |
| -- If the expression raises a constraint error, then so does |
| -- the attribute reference. We keep going in this case because |
| -- we are still interested in whether the attribute reference |
| -- is static even if it is not static. |
| |
| elsif Raises_Constraint_Error (E) then |
| Set_Raises_Constraint_Error (N); |
| end if; |
| |
| Next (E); |
| end loop; |
| |
| if Raises_Constraint_Error (Prefix (N)) then |
| Set_Is_Static_Expression (N, False); |
| return; |
| end if; |
| end; |
| |
| -- Deal with the case of a static attribute reference that raises |
| -- constraint error. The Raises_Constraint_Error flag will already |
| -- have been set, and the Static flag shows whether the attribute |
| -- reference is static. In any case we certainly can't fold such an |
| -- attribute reference. |
| |
| -- Note that the rewriting of the attribute node with the constraint |
| -- error node is essential in this case, because otherwise Gigi might |
| -- blow up on one of the attributes it never expects to see. |
| |
| -- The constraint_error node must have the type imposed by the context, |
| -- to avoid spurious errors in the enclosing expression. |
| |
| if Raises_Constraint_Error (N) then |
| CE_Node := |
| Make_Raise_Constraint_Error (Sloc (N), |
| Reason => CE_Range_Check_Failed); |
| Set_Etype (CE_Node, Etype (N)); |
| Set_Raises_Constraint_Error (CE_Node); |
| Check_Expressions; |
| Rewrite (N, Relocate_Node (CE_Node)); |
| Set_Raises_Constraint_Error (N, True); |
| return; |
| end if; |
| |
| -- At this point we have a potentially foldable attribute reference. |
| -- If Static is set, then the attribute reference definitely obeys |
| -- the requirements in (RM 4.9(7,8,22)), and it definitely can be |
| -- folded. If Static is not set, then the attribute may or may not |
| -- be foldable, and the individual attribute processing routines |
| -- test Static as required in cases where it makes a difference. |
| |
| -- In the case where Static is not set, we do know that all the |
| -- expressions present are at least known at compile time (we assumed |
| -- above that if this was not the case, then there was no hope of static |
| -- evaluation). However, we did not require that the bounds of the |
| -- prefix type be compile time known, let alone static). That's because |
| -- there are many attributes that can be computed at compile time on |
| -- non-static subtypes, even though such references are not static |
| -- expressions. |
| |
| -- For VAX float, the root type is an IEEE type. So make sure to use the |
| -- base type instead of the root-type for floating point attributes. |
| |
| case Id is |
| |
| -- Attributes related to Ada 2012 iterators; nothing to evaluate for |
| -- these. |
| |
| when Attribute_Constant_Indexing |
| | Attribute_Default_Iterator |
| | Attribute_Implicit_Dereference |
| | Attribute_Iterator_Element |
| | Attribute_Iterable |
| | Attribute_Variable_Indexing |
| => |
| null; |
| |
| -- Internal attributes used to deal with Ada 2012 delayed aspects. |
| -- These were already rejected by the parser. Thus they shouldn't |
| -- appear here. |
| |
| when Internal_Attribute_Id => |
| raise Program_Error; |
| |
| -------------- |
| -- Adjacent -- |
| -------------- |
| |
| when Attribute_Adjacent => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Adjacent |
| (P_Base_Type, Expr_Value_R (E1), Expr_Value_R (E2)), |
| Static); |
| |
| --------- |
| -- Aft -- |
| --------- |
| |
| when Attribute_Aft => |
| Fold_Uint (N, Aft_Value (P_Type), Static); |
| |
| --------------- |
| -- Alignment -- |
| --------------- |
| |
| when Attribute_Alignment => Alignment_Block : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| -- Fold if alignment is set and not otherwise |
| |
| if Known_Alignment (P_TypeA) then |
| Fold_Uint (N, Alignment (P_TypeA), Static); |
| end if; |
| end Alignment_Block; |
| |
| ----------------------------- |
| -- Atomic_Always_Lock_Free -- |
| ----------------------------- |
| |
| -- Atomic_Always_Lock_Free attribute is a Boolean, thus no need to fold |
| -- here. |
| |
| when Attribute_Atomic_Always_Lock_Free => Atomic_Always_Lock_Free : |
| declare |
| V : constant Entity_Id := |
| Boolean_Literals |
| (Support_Atomic_Primitives_On_Target |
| and then Support_Atomic_Primitives (P_Type)); |
| |
| begin |
| Rewrite (N, New_Occurrence_Of (V, Loc)); |
| |
| -- Analyze and resolve as boolean. Note that this attribute is a |
| -- static attribute in GNAT. |
| |
| Analyze_And_Resolve (N, Standard_Boolean); |
| Static := True; |
| Set_Is_Static_Expression (N, True); |
| end Atomic_Always_Lock_Free; |
| |
| --------- |
| -- Bit -- |
| --------- |
| |
| -- Bit can never be folded |
| |
| when Attribute_Bit => |
| null; |
| |
| ------------------ |
| -- Body_Version -- |
| ------------------ |
| |
| -- Body_version can never be static |
| |
| when Attribute_Body_Version => |
| null; |
| |
| ------------- |
| -- Ceiling -- |
| ------------- |
| |
| when Attribute_Ceiling => |
| Fold_Ureal |
| (N, Eval_Fat.Ceiling (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| -------------------- |
| -- Component_Size -- |
| -------------------- |
| |
| when Attribute_Component_Size => |
| if Known_Static_Component_Size (P_Type) then |
| Fold_Uint (N, Component_Size (P_Type), Static); |
| end if; |
| |
| ------------- |
| -- Compose -- |
| ------------- |
| |
| when Attribute_Compose => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Compose (P_Base_Type, Expr_Value_R (E1), Expr_Value (E2)), |
| Static); |
| |
| ----------------- |
| -- Constrained -- |
| ----------------- |
| |
| -- Constrained is never folded for now, there may be cases that |
| -- could be handled at compile time. To be looked at later. |
| |
| when Attribute_Constrained => |
| |
| -- The expander might fold it and set the static flag accordingly, |
| -- but with expansion disabled (as in ASIS), it remains as an |
| -- attribute reference, and this reference is not static. |
| |
| Set_Is_Static_Expression (N, False); |
| null; |
| |
| --------------- |
| -- Copy_Sign -- |
| --------------- |
| |
| when Attribute_Copy_Sign => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Copy_Sign |
| (P_Base_Type, Expr_Value_R (E1), Expr_Value_R (E2)), |
| Static); |
| |
| -------------- |
| -- Definite -- |
| -------------- |
| |
| when Attribute_Definite => |
| Rewrite (N, New_Occurrence_Of ( |
| Boolean_Literals (Is_Definite_Subtype (P_Entity)), Loc)); |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| ----------- |
| -- Delta -- |
| ----------- |
| |
| when Attribute_Delta => |
| Fold_Ureal (N, Delta_Value (P_Type), True); |
| |
| ------------ |
| -- Denorm -- |
| ------------ |
| |
| when Attribute_Denorm => |
| Fold_Uint |
| (N, UI_From_Int (Boolean'Pos (Has_Denormals (P_Type))), Static); |
| |
| --------------------- |
| -- Descriptor_Size -- |
| --------------------- |
| |
| when Attribute_Descriptor_Size => |
| null; |
| |
| ------------ |
| -- Digits -- |
| ------------ |
| |
| when Attribute_Digits => |
| Fold_Uint (N, Digits_Value (P_Type), Static); |
| |
| ---------- |
| -- Emax -- |
| ---------- |
| |
| when Attribute_Emax => |
| |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Emax = 4 * T'Mantissa |
| |
| Fold_Uint (N, 4 * Mantissa, Static); |
| |
| -------------- |
| -- Enum_Rep -- |
| -------------- |
| |
| when Attribute_Enum_Rep => Enum_Rep : declare |
| Val : Node_Id; |
| |
| begin |
| -- The attribute appears in the form: |
| |
| -- Enum_Typ'Enum_Rep (Const) |
| -- Enum_Typ'Enum_Rep (Enum_Lit) |
| |
| if Present (E1) then |
| Val := E1; |
| |
| -- Otherwise the prefix denotes a constant or enumeration literal: |
| |
| -- Const'Enum_Rep |
| -- Enum_Lit'Enum_Rep |
| |
| else |
| Val := P; |
| end if; |
| |
| -- For an enumeration type with a non-standard representation use |
| -- the Enumeration_Rep field of the proper constant. Note that this |
| -- will not work for types Character/Wide_[Wide-]Character, since no |
| -- real entities are created for the enumeration literals, but that |
| -- does not matter since these two types do not have non-standard |
| -- representations anyway. |
| |
| if Is_Enumeration_Type (P_Type) |
| and then Has_Non_Standard_Rep (P_Type) |
| then |
| Fold_Uint (N, Enumeration_Rep (Expr_Value_E (Val)), Static); |
| |
| -- For enumeration types with standard representations and all other |
| -- cases (i.e. all integer and modular types), Enum_Rep is equivalent |
| -- to Pos. |
| |
| else |
| Fold_Uint (N, Expr_Value (Val), Static); |
| end if; |
| end Enum_Rep; |
| |
| -------------- |
| -- Enum_Val -- |
| -------------- |
| |
| when Attribute_Enum_Val => Enum_Val : declare |
| Lit : Node_Id; |
| |
| begin |
| -- We have something like Enum_Type'Enum_Val (23), so search for a |
| -- corresponding value in the list of Enum_Rep values for the type. |
| |
| Lit := First_Literal (P_Base_Type); |
| loop |
| if Enumeration_Rep (Lit) = Expr_Value (E1) then |
| Fold_Uint (N, Enumeration_Pos (Lit), Static); |
| exit; |
| end if; |
| |
| Next_Literal (Lit); |
| |
| if No (Lit) then |
| Apply_Compile_Time_Constraint_Error |
| (N, "no representation value matches", |
| CE_Range_Check_Failed, |
| Warn => not Static); |
| exit; |
| end if; |
| end loop; |
| end Enum_Val; |
| |
| ------------- |
| -- Epsilon -- |
| ------------- |
| |
| when Attribute_Epsilon => |
| |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Epsilon = 2.0**(1 - T'Mantissa) |
| |
| Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True); |
| |
| -------------- |
| -- Exponent -- |
| -------------- |
| |
| when Attribute_Exponent => |
| Fold_Uint (N, |
| Eval_Fat.Exponent (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| ----------------------- |
| -- Finalization_Size -- |
| ----------------------- |
| |
| when Attribute_Finalization_Size => |
| null; |
| |
| ----------- |
| -- First -- |
| ----------- |
| |
| when Attribute_First => |
| Set_Bounds; |
| |
| if Compile_Time_Known_Value (Lo_Bound) then |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static); |
| else |
| Fold_Uint (N, Expr_Value (Lo_Bound), Static); |
| end if; |
| |
| else |
| Check_Concurrent_Discriminant (Lo_Bound); |
| end if; |
| |
| ----------------- |
| -- First_Valid -- |
| ----------------- |
| |
| when Attribute_First_Valid => |
| if Has_Predicates (P_Type) |
| and then Has_Static_Predicate (P_Type) |
| then |
| declare |
| FirstN : constant Node_Id := |
| First (Static_Discrete_Predicate (P_Type)); |
| begin |
| if Nkind (FirstN) = N_Range then |
| Fold_Uint (N, Expr_Value (Low_Bound (FirstN)), Static); |
| else |
| Fold_Uint (N, Expr_Value (FirstN), Static); |
| end if; |
| end; |
| |
| else |
| Set_Bounds; |
| Fold_Uint (N, Expr_Value (Lo_Bound), Static); |
| end if; |
| |
| ----------------- |
| -- Fixed_Value -- |
| ----------------- |
| |
| when Attribute_Fixed_Value => |
| null; |
| |
| ----------- |
| -- Floor -- |
| ----------- |
| |
| when Attribute_Floor => |
| Fold_Ureal |
| (N, Eval_Fat.Floor (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| ---------- |
| -- Fore -- |
| ---------- |
| |
| when Attribute_Fore => |
| if Compile_Time_Known_Bounds (P_Type) then |
| Fold_Uint (N, UI_From_Int (Fore_Value), Static); |
| end if; |
| |
| -------------- |
| -- Fraction -- |
| -------------- |
| |
| when Attribute_Fraction => |
| Fold_Ureal |
| (N, Eval_Fat.Fraction (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| ----------------------- |
| -- Has_Access_Values -- |
| ----------------------- |
| |
| when Attribute_Has_Access_Values => |
| Rewrite (N, New_Occurrence_Of |
| (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc)); |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| ----------------------- |
| -- Has_Discriminants -- |
| ----------------------- |
| |
| when Attribute_Has_Discriminants => |
| Rewrite (N, New_Occurrence_Of ( |
| Boolean_Literals (Has_Discriminants (P_Entity)), Loc)); |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| ---------------------- |
| -- Has_Same_Storage -- |
| ---------------------- |
| |
| when Attribute_Has_Same_Storage => |
| null; |
| |
| ----------------------- |
| -- Has_Tagged_Values -- |
| ----------------------- |
| |
| when Attribute_Has_Tagged_Values => |
| Rewrite (N, New_Occurrence_Of |
| (Boolean_Literals (Has_Tagged_Component (P_Root_Type)), Loc)); |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| -------------- |
| -- Identity -- |
| -------------- |
| |
| when Attribute_Identity => |
| null; |
| |
| ----------- |
| -- Image -- |
| ----------- |
| |
| -- Image is a scalar attribute, but is never static, because it is |
| -- not a static function (having a non-scalar argument (RM 4.9(22)) |
| -- However, we can constant-fold the image of an enumeration literal |
| -- if names are available. |
| |
| when Attribute_Image => |
| if Is_Entity_Name (E1) |
| and then Ekind (Entity (E1)) = E_Enumeration_Literal |
| and then not Discard_Names (First_Subtype (Etype (E1))) |
| and then not Global_Discard_Names |
| then |
| declare |
| Lit : constant Entity_Id := Entity (E1); |
| Str : String_Id; |
| begin |
| Start_String; |
| Get_Unqualified_Decoded_Name_String (Chars (Lit)); |
| Set_Casing (All_Upper_Case); |
| Store_String_Chars (Name_Buffer (1 .. Name_Len)); |
| Str := End_String; |
| Rewrite (N, Make_String_Literal (Loc, Strval => Str)); |
| Analyze_And_Resolve (N, Standard_String); |
| Set_Is_Static_Expression (N, False); |
| end; |
| end if; |
| |
| ------------------- |
| -- Integer_Value -- |
| ------------------- |
| |
| -- We never try to fold Integer_Value (though perhaps we could???) |
| |
| when Attribute_Integer_Value => |
| null; |
| |
| ------------------- |
| -- Invalid_Value -- |
| ------------------- |
| |
| -- Invalid_Value is a scalar attribute that is never static, because |
| -- the value is by design out of range. |
| |
| when Attribute_Invalid_Value => |
| null; |
| |
| ----------- |
| -- Large -- |
| ----------- |
| |
| when Attribute_Large => |
| |
| -- For fixed-point, we use the identity: |
| |
| -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Rewrite (N, |
| Make_Op_Multiply (Loc, |
| Left_Opnd => |
| Make_Op_Subtract (Loc, |
| Left_Opnd => |
| Make_Op_Expon (Loc, |
| Left_Opnd => |
| Make_Real_Literal (Loc, Ureal_2), |
| Right_Opnd => |
| Make_Attribute_Reference (Loc, |
| Prefix => P, |
| Attribute_Name => Name_Mantissa)), |
| Right_Opnd => Make_Real_Literal (Loc, Ureal_1)), |
| |
| Right_Opnd => |
| Make_Real_Literal (Loc, Small_Value (Entity (P))))); |
| |
| Analyze_And_Resolve (N, C_Type); |
| |
| -- Floating-point (Ada 83 compatibility) |
| |
| else |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa)) |
| |
| -- where |
| |
| -- T'Emax = 4 * T'Mantissa |
| |
| Fold_Ureal |
| (N, |
| Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)), |
| True); |
| end if; |
| |
| --------------- |
| -- Lock_Free -- |
| --------------- |
| |
| when Attribute_Lock_Free => Lock_Free : declare |
| V : constant Entity_Id := Boolean_Literals (Uses_Lock_Free (P_Type)); |
| |
| begin |
| Rewrite (N, New_Occurrence_Of (V, Loc)); |
| |
| -- Analyze and resolve as boolean. Note that this attribute is a |
| -- static attribute in GNAT. |
| |
| Analyze_And_Resolve (N, Standard_Boolean); |
| Static := True; |
| Set_Is_Static_Expression (N, True); |
| end Lock_Free; |
| |
| ---------- |
| -- Last -- |
| ---------- |
| |
| when Attribute_Last => |
| Set_Bounds; |
| |
| if Compile_Time_Known_Value (Hi_Bound) then |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static); |
| else |
| Fold_Uint (N, Expr_Value (Hi_Bound), Static); |
| end if; |
| |
| else |
| Check_Concurrent_Discriminant (Hi_Bound); |
| end if; |
| |
| ---------------- |
| -- Last_Valid -- |
| ---------------- |
| |
| when Attribute_Last_Valid => |
| if Has_Predicates (P_Type) |
| and then Has_Static_Predicate (P_Type) |
| then |
| declare |
| LastN : constant Node_Id := |
| Last (Static_Discrete_Predicate (P_Type)); |
| begin |
| if Nkind (LastN) = N_Range then |
| Fold_Uint (N, Expr_Value (High_Bound (LastN)), Static); |
| else |
| Fold_Uint (N, Expr_Value (LastN), Static); |
| end if; |
| end; |
| |
| else |
| Set_Bounds; |
| Fold_Uint (N, Expr_Value (Hi_Bound), Static); |
| end if; |
| |
| ------------------ |
| -- Leading_Part -- |
| ------------------ |
| |
| when Attribute_Leading_Part => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Leading_Part |
| (P_Base_Type, Expr_Value_R (E1), Expr_Value (E2)), |
| Static); |
| |
| ------------ |
| -- Length -- |
| ------------ |
| |
| when Attribute_Length => Length : declare |
| Ind : Node_Id; |
| |
| begin |
| -- If any index type is a formal type, or derived from one, the |
| -- bounds are not static. Treating them as static can produce |
| -- spurious warnings or improper constant folding. |
| |
| Ind := First_Index (P_Type); |
| while Present (Ind) loop |
| if Is_Generic_Type (Root_Type (Etype (Ind))) then |
| return; |
| end if; |
| |
| Next_Index (Ind); |
| end loop; |
| |
| Set_Bounds; |
| |
| -- For two compile time values, we can compute length |
| |
| if Compile_Time_Known_Value (Lo_Bound) |
| and then Compile_Time_Known_Value (Hi_Bound) |
| then |
| Fold_Uint (N, |
| UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))), |
| Static); |
| end if; |
| |
| -- One more case is where Hi_Bound and Lo_Bound are compile-time |
| -- comparable, and we can figure out the difference between them. |
| |
| declare |
| Diff : aliased Uint; |
| |
| begin |
| case |
| Compile_Time_Compare |
| (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False) |
| is |
| when EQ => |
| Fold_Uint (N, Uint_1, Static); |
| |
| when GT => |
| Fold_Uint (N, Uint_0, Static); |
| |
| when LT => |
| if Diff /= No_Uint then |
| Fold_Uint (N, Diff + 1, Static); |
| end if; |
| |
| when others => |
| null; |
| end case; |
| end; |
| end Length; |
| |
| ---------------- |
| -- Loop_Entry -- |
| ---------------- |
| |
| -- Loop_Entry acts as an alias of a constant initialized to the prefix |
| -- of the said attribute at the point of entry into the related loop. As |
| -- such, the attribute reference does not need to be evaluated because |
| -- the prefix is the one that is evaluted. |
| |
| when Attribute_Loop_Entry => |
| null; |
| |
| ------------- |
| -- Machine -- |
| ------------- |
| |
| when Attribute_Machine => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Machine |
| (P_Base_Type, Expr_Value_R (E1), Eval_Fat.Round, N), |
| Static); |
| |
| ------------------ |
| -- Machine_Emax -- |
| ------------------ |
| |
| when Attribute_Machine_Emax => |
| Fold_Uint (N, Machine_Emax_Value (P_Type), Static); |
| |
| ------------------ |
| -- Machine_Emin -- |
| ------------------ |
| |
| when Attribute_Machine_Emin => |
| Fold_Uint (N, Machine_Emin_Value (P_Type), Static); |
| |
| ---------------------- |
| -- Machine_Mantissa -- |
| ---------------------- |
| |
| when Attribute_Machine_Mantissa => |
| Fold_Uint (N, Machine_Mantissa_Value (P_Type), Static); |
| |
| ----------------------- |
| -- Machine_Overflows -- |
| ----------------------- |
| |
| when Attribute_Machine_Overflows => |
| |
| -- Always true for fixed-point |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Uint (N, True_Value, Static); |
| |
| -- Floating point case |
| |
| else |
| Fold_Uint (N, |
| UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)), |
| Static); |
| end if; |
| |
| ------------------- |
| -- Machine_Radix -- |
| ------------------- |
| |
| when Attribute_Machine_Radix => |
| if Is_Fixed_Point_Type (P_Type) then |
| if Is_Decimal_Fixed_Point_Type (P_Type) |
| and then Machine_Radix_10 (P_Type) |
| then |
| Fold_Uint (N, Uint_10, Static); |
| else |
| Fold_Uint (N, Uint_2, Static); |
| end if; |
| |
| -- All floating-point type always have radix 2 |
| |
| else |
| Fold_Uint (N, Uint_2, Static); |
| end if; |
| |
| ---------------------- |
| -- Machine_Rounding -- |
| ---------------------- |
| |
| -- Note: for the folding case, it is fine to treat Machine_Rounding |
| -- exactly the same way as Rounding, since this is one of the allowed |
| -- behaviors, and performance is not an issue here. It might be a bit |
| -- better to give the same result as it would give at run time, even |
| -- though the non-determinism is certainly permitted. |
| |
| when Attribute_Machine_Rounding => |
| Fold_Ureal |
| (N, Eval_Fat.Rounding (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| -------------------- |
| -- Machine_Rounds -- |
| -------------------- |
| |
| when Attribute_Machine_Rounds => |
| |
| -- Always False for fixed-point |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Uint (N, False_Value, Static); |
| |
| -- Else yield proper floating-point result |
| |
| else |
| Fold_Uint |
| (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), |
| Static); |
| end if; |
| |
| ------------------ |
| -- Machine_Size -- |
| ------------------ |
| |
| -- Note: Machine_Size is identical to Object_Size |
| |
| when Attribute_Machine_Size => Machine_Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if Known_Esize (P_TypeA) then |
| Fold_Uint (N, Esize (P_TypeA), Static); |
| end if; |
| end Machine_Size; |
| |
| -------------- |
| -- Mantissa -- |
| -------------- |
| |
| when Attribute_Mantissa => |
| |
| -- Fixed-point mantissa |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| |
| -- Compile time foldable case |
| |
| if Compile_Time_Known_Value (Type_Low_Bound (P_Type)) |
| and then |
| Compile_Time_Known_Value (Type_High_Bound (P_Type)) |
| then |
| -- The calculation of the obsolete Ada 83 attribute Mantissa |
| -- is annoying, because of AI00143, quoted here: |
| |
| -- !question 84-01-10 |
| |
| -- Consider the model numbers for F: |
| |
| -- type F is delta 1.0 range -7.0 .. 8.0; |
| |
| -- The wording requires that F'MANTISSA be the SMALLEST |
| -- integer number for which each bound of the specified |
| -- range is either a model number or lies at most small |
| -- distant from a model number. This means F'MANTISSA |
| -- is required to be 3 since the range -7.0 .. 7.0 fits |
| -- in 3 signed bits, and 8 is "at most" 1.0 from a model |
| -- number, namely, 7. Is this analysis correct? Note that |
| -- this implies the upper bound of the range is not |
| -- represented as a model number. |
| |
| -- !response 84-03-17 |
| |
| -- The analysis is correct. The upper and lower bounds for |
| -- a fixed point type can lie outside the range of model |
| -- numbers. |
| |
| declare |
| Siz : Uint; |
| LBound : Ureal; |
| UBound : Ureal; |
| Bound : Ureal; |
| Max_Man : Uint; |
| |
| begin |
| LBound := Expr_Value_R (Type_Low_Bound (P_Type)); |
| UBound := Expr_Value_R (Type_High_Bound (P_Type)); |
| Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound)); |
| Max_Man := UR_Trunc (Bound / Small_Value (P_Type)); |
| |
| -- If the Bound is exactly a model number, i.e. a multiple |
| -- of Small, then we back it off by one to get the integer |
| -- value that must be representable. |
| |
| if Small_Value (P_Type) * Max_Man = Bound then |
| Max_Man := Max_Man - 1; |
| end if; |
| |
| -- Now find corresponding size = Mantissa value |
| |
| Siz := Uint_0; |
| while 2 ** Siz < Max_Man loop |
| Siz := Siz + 1; |
| end loop; |
| |
| Fold_Uint (N, Siz, Static); |
| end; |
| |
| else |
| -- The case of dynamic bounds cannot be evaluated at compile |
| -- time. Instead we use a runtime routine (see Exp_Attr). |
| |
| null; |
| end if; |
| |
| -- Floating-point Mantissa |
| |
| else |
| Fold_Uint (N, Mantissa, Static); |
| end if; |
| |
| --------- |
| -- Max -- |
| --------- |
| |
| when Attribute_Max => |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal |
| (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static); |
| else |
| Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static); |
| end if; |
| |
| ---------------------------------- |
| -- Max_Alignment_For_Allocation -- |
| ---------------------------------- |
| |
| -- Max_Alignment_For_Allocation is usually the Alignment. However, |
| -- arrays are allocated with dope, so we need to take into account both |
| -- the alignment of the array, which comes from the component alignment, |
| -- and the alignment of the dope. Also, if the alignment is unknown, we |
| -- use the max (it's OK to be pessimistic). |
| |
| when Attribute_Max_Alignment_For_Allocation => Max_Align : declare |
| A : Uint := UI_From_Int (Ttypes.Maximum_Alignment); |
| begin |
| if Known_Alignment (P_Type) |
| and then (not Is_Array_Type (P_Type) or else Alignment (P_Type) > A) |
| then |
| A := Alignment (P_Type); |
| end if; |
| |
| Fold_Uint (N, A, Static); |
| end Max_Align; |
| |
| ---------------------------------- |
| -- Max_Size_In_Storage_Elements -- |
| ---------------------------------- |
| |
| -- Max_Size_In_Storage_Elements is simply the Size rounded up to a |
| -- Storage_Unit boundary. We can fold any cases for which the size |
| -- is known by the front end. |
| |
| when Attribute_Max_Size_In_Storage_Elements => |
| if Known_Esize (P_Type) then |
| Fold_Uint (N, |
| (Esize (P_Type) + System_Storage_Unit - 1) / |
| System_Storage_Unit, |
| Static); |
| end if; |
| |
| -------------------- |
| -- Mechanism_Code -- |
| -------------------- |
| |
| when Attribute_Mechanism_Code => Mechanism_Code : declare |
| Formal : Entity_Id; |
| Mech : Mechanism_Type; |
| Val : Int; |
| |
| begin |
| if No (E1) then |
| Mech := Mechanism (P_Entity); |
| |
| else |
| Val := UI_To_Int (Expr_Value (E1)); |
| |
| Formal := First_Formal (P_Entity); |
| for J in 1 .. Val - 1 loop |
| Next_Formal (Formal); |
| end loop; |
| |
| Mech := Mechanism (Formal); |
| end if; |
| |
| if Mech < 0 then |
| Fold_Uint (N, UI_From_Int (Int (-Mech)), Static); |
| end if; |
| end Mechanism_Code; |
| |
| --------- |
| -- Min -- |
| --------- |
| |
| when Attribute_Min => |
| if Is_Real_Type (P_Type) then |
| Fold_Ureal |
| (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static); |
| else |
| Fold_Uint |
| (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static); |
| end if; |
| |
| --------- |
| -- Mod -- |
| --------- |
| |
| when Attribute_Mod => |
| Fold_Uint |
| (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static); |
| |
| ----------- |
| -- Model -- |
| ----------- |
| |
| when Attribute_Model => |
| Fold_Ureal |
| (N, Eval_Fat.Model (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| ---------------- |
| -- Model_Emin -- |
| ---------------- |
| |
| when Attribute_Model_Emin => |
| Fold_Uint (N, Model_Emin_Value (P_Base_Type), Static); |
| |
| ------------------- |
| -- Model_Epsilon -- |
| ------------------- |
| |
| when Attribute_Model_Epsilon => |
| Fold_Ureal (N, Model_Epsilon_Value (P_Base_Type), Static); |
| |
| -------------------- |
| -- Model_Mantissa -- |
| -------------------- |
| |
| when Attribute_Model_Mantissa => |
| Fold_Uint (N, Model_Mantissa_Value (P_Base_Type), Static); |
| |
| ----------------- |
| -- Model_Small -- |
| ----------------- |
| |
| when Attribute_Model_Small => |
| Fold_Ureal (N, Model_Small_Value (P_Base_Type), Static); |
| |
| ------------- |
| -- Modulus -- |
| ------------- |
| |
| when Attribute_Modulus => |
| Fold_Uint (N, Modulus (P_Type), Static); |
| |
| -------------------- |
| -- Null_Parameter -- |
| -------------------- |
| |
| -- Cannot fold, we know the value sort of, but the whole point is |
| -- that there is no way to talk about this imaginary value except |
| -- by using the attribute, so we leave it the way it is. |
| |
| when Attribute_Null_Parameter => |
| null; |
| |
| ----------------- |
| -- Object_Size -- |
| ----------------- |
| |
| -- The Object_Size attribute for a type returns the Esize of the |
| -- type and can be folded if this value is known. |
| |
| when Attribute_Object_Size => Object_Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if Known_Esize (P_TypeA) then |
| Fold_Uint (N, Esize (P_TypeA), Static); |
| end if; |
| end Object_Size; |
| |
| ---------------------- |
| -- Overlaps_Storage -- |
| ---------------------- |
| |
| when Attribute_Overlaps_Storage => |
| null; |
| |
| ------------------------- |
| -- Passed_By_Reference -- |
| ------------------------- |
| |
| -- Scalar types are never passed by reference |
| |
| when Attribute_Passed_By_Reference => |
| Fold_Uint (N, False_Value, Static); |
| |
| --------- |
| -- Pos -- |
| --------- |
| |
| when Attribute_Pos => |
| Fold_Uint (N, Expr_Value (E1), Static); |
| |
| ---------- |
| -- Pred -- |
| ---------- |
| |
| when Attribute_Pred => |
| |
| -- Floating-point case |
| |
| if Is_Floating_Point_Type (P_Type) then |
| Fold_Ureal |
| (N, Eval_Fat.Pred (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| -- Fixed-point case |
| |
| elsif Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal |
| (N, Expr_Value_R (E1) - Small_Value (P_Type), True); |
| |
| -- Modular integer case (wraps) |
| |
| elsif Is_Modular_Integer_Type (P_Type) then |
| Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static); |
| |
| -- Other scalar cases |
| |
| else |
| pragma Assert (Is_Scalar_Type (P_Type)); |
| |
| if Is_Enumeration_Type (P_Type) |
| and then Expr_Value (E1) = |
| Expr_Value (Type_Low_Bound (P_Base_Type)) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "Pred of `&''First`", |
| CE_Overflow_Check_Failed, |
| Ent => P_Base_Type, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| end if; |
| |
| Fold_Uint (N, Expr_Value (E1) - 1, Static); |
| end if; |
| |
| ----------- |
| -- Range -- |
| ----------- |
| |
| -- No processing required, because by this stage, Range has been |
| -- replaced by First .. Last, so this branch can never be taken. |
| |
| when Attribute_Range => |
| raise Program_Error; |
| |
| ------------------ |
| -- Range_Length -- |
| ------------------ |
| |
| when Attribute_Range_Length => Range_Length : declare |
| Diff : aliased Uint; |
| |
| begin |
| Set_Bounds; |
| |
| -- Can fold if both bounds are compile time known |
| |
| if Compile_Time_Known_Value (Hi_Bound) |
| and then Compile_Time_Known_Value (Lo_Bound) |
| then |
| Fold_Uint (N, |
| UI_Max |
| (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1), |
| Static); |
| end if; |
| |
| -- One more case is where Hi_Bound and Lo_Bound are compile-time |
| -- comparable, and we can figure out the difference between them. |
| |
| case Compile_Time_Compare |
| (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False) |
| is |
| when EQ => |
| Fold_Uint (N, Uint_1, Static); |
| |
| when GT => |
| Fold_Uint (N, Uint_0, Static); |
| |
| when LT => |
| if Diff /= No_Uint then |
| Fold_Uint (N, Diff + 1, Static); |
| end if; |
| |
| when others => |
| null; |
| end case; |
| end Range_Length; |
| |
| --------- |
| -- Ref -- |
| --------- |
| |
| when Attribute_Ref => |
| Fold_Uint (N, Expr_Value (E1), Static); |
| |
| --------------- |
| -- Remainder -- |
| --------------- |
| |
| when Attribute_Remainder => Remainder : declare |
| X : constant Ureal := Expr_Value_R (E1); |
| Y : constant Ureal := Expr_Value_R (E2); |
| |
| begin |
| if UR_Is_Zero (Y) then |
| Apply_Compile_Time_Constraint_Error |
| (N, "division by zero in Remainder", |
| CE_Overflow_Check_Failed, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| end if; |
| |
| Fold_Ureal (N, Eval_Fat.Remainder (P_Base_Type, X, Y), Static); |
| end Remainder; |
| |
| ----------------- |
| -- Restriction -- |
| ----------------- |
| |
| when Attribute_Restriction_Set => |
| Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); |
| Set_Is_Static_Expression (N); |
| |
| ----------- |
| -- Round -- |
| ----------- |
| |
| when Attribute_Round => Round : declare |
| Sr : Ureal; |
| Si : Uint; |
| |
| begin |
| -- First we get the (exact result) in units of small |
| |
| Sr := Expr_Value_R (E1) / Small_Value (C_Type); |
| |
| -- Now round that exactly to an integer |
| |
| Si := UR_To_Uint (Sr); |
| |
| -- Finally the result is obtained by converting back to real |
| |
| Fold_Ureal (N, Si * Small_Value (C_Type), Static); |
| end Round; |
| |
| -------------- |
| -- Rounding -- |
| -------------- |
| |
| when Attribute_Rounding => |
| Fold_Ureal |
| (N, Eval_Fat.Rounding (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| --------------- |
| -- Safe_Emax -- |
| --------------- |
| |
| when Attribute_Safe_Emax => |
| Fold_Uint (N, Safe_Emax_Value (P_Type), Static); |
| |
| ---------------- |
| -- Safe_First -- |
| ---------------- |
| |
| when Attribute_Safe_First => |
| Fold_Ureal (N, Safe_First_Value (P_Type), Static); |
| |
| ---------------- |
| -- Safe_Large -- |
| ---------------- |
| |
| when Attribute_Safe_Large => |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal |
| (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static); |
| else |
| Fold_Ureal (N, Safe_Last_Value (P_Type), Static); |
| end if; |
| |
| --------------- |
| -- Safe_Last -- |
| --------------- |
| |
| when Attribute_Safe_Last => |
| Fold_Ureal (N, Safe_Last_Value (P_Type), Static); |
| |
| ---------------- |
| -- Safe_Small -- |
| ---------------- |
| |
| when Attribute_Safe_Small => |
| |
| -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant |
| -- for fixed-point, since is the same as Small, but we implement |
| -- it for backwards compatibility. |
| |
| if Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal (N, Small_Value (P_Type), Static); |
| |
| -- Ada 83 Safe_Small for floating-point cases |
| |
| else |
| Fold_Ureal (N, Model_Small_Value (P_Type), Static); |
| end if; |
| |
| ----------- |
| -- Scale -- |
| ----------- |
| |
| when Attribute_Scale => |
| Fold_Uint (N, Scale_Value (P_Type), Static); |
| |
| ------------- |
| -- Scaling -- |
| ------------- |
| |
| when Attribute_Scaling => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Scaling |
| (P_Base_Type, Expr_Value_R (E1), Expr_Value (E2)), |
| Static); |
| |
| ------------------ |
| -- Signed_Zeros -- |
| ------------------ |
| |
| when Attribute_Signed_Zeros => |
| Fold_Uint |
| (N, UI_From_Int (Boolean'Pos (Has_Signed_Zeros (P_Type))), Static); |
| |
| ---------- |
| -- Size -- |
| ---------- |
| |
| -- Size attribute returns the RM size. All scalar types can be folded, |
| -- as well as any types for which the size is known by the front end, |
| -- including any type for which a size attribute is specified. This is |
| -- one of the places where it is annoying that a size of zero means two |
| -- things (zero size for scalars, unspecified size for non-scalars). |
| |
| when Attribute_Size |
| | Attribute_VADS_Size |
| => |
| Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if Is_Scalar_Type (P_TypeA) |
| or else RM_Size (P_TypeA) /= Uint_0 |
| then |
| -- VADS_Size case |
| |
| if Id = Attribute_VADS_Size or else Use_VADS_Size then |
| declare |
| S : constant Node_Id := Size_Clause (P_TypeA); |
| |
| begin |
| -- If a size clause applies, then use the size from it. |
| -- This is one of the rare cases where we can use the |
| -- Size_Clause field for a subtype when Has_Size_Clause |
| -- is False. Consider: |
| |
| -- type x is range 1 .. 64; |
| -- for x'size use 12; |
| -- subtype y is x range 0 .. 3; |
| |
| -- Here y has a size clause inherited from x, but |
| -- normally it does not apply, and y'size is 2. However, |
| -- y'VADS_Size is indeed 12 and not 2. |
| |
| if Present (S) |
| and then Is_OK_Static_Expression (Expression (S)) |
| then |
| Fold_Uint (N, Expr_Value (Expression (S)), Static); |
| |
| -- If no size is specified, then we simply use the object |
| -- size in the VADS_Size case (e.g. Natural'Size is equal |
| -- to Integer'Size, not one less). |
| |
| else |
| Fold_Uint (N, Esize (P_TypeA), Static); |
| end if; |
| end; |
| |
| -- Normal case (Size) in which case we want the RM_Size |
| |
| else |
| Fold_Uint (N, RM_Size (P_TypeA), Static); |
| end if; |
| end if; |
| end Size; |
| |
| ----------- |
| -- Small -- |
| ----------- |
| |
| when Attribute_Small => |
| |
| -- The floating-point case is present only for Ada 83 compatibility. |
| -- Note that strictly this is an illegal addition, since we are |
| -- extending an Ada 95 defined attribute, but we anticipate an |
| -- ARG ruling that will permit this. |
| |
| if Is_Floating_Point_Type (P_Type) then |
| |
| -- Ada 83 attribute is defined as (RM83 3.5.8) |
| |
| -- T'Small = 2.0**(-T'Emax - 1) |
| |
| -- where |
| |
| -- T'Emax = 4 * T'Mantissa |
| |
| Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static); |
| |
| -- Normal Ada 95 fixed-point case |
| |
| else |
| Fold_Ureal (N, Small_Value (P_Type), True); |
| end if; |
| |
| ----------------- |
| -- Stream_Size -- |
| ----------------- |
| |
| when Attribute_Stream_Size => |
| null; |
| |
| ---------- |
| -- Succ -- |
| ---------- |
| |
| when Attribute_Succ => |
| -- Floating-point case |
| |
| if Is_Floating_Point_Type (P_Type) then |
| Fold_Ureal |
| (N, Eval_Fat.Succ (P_Base_Type, Expr_Value_R (E1)), Static); |
| |
| -- Fixed-point case |
| |
| elsif Is_Fixed_Point_Type (P_Type) then |
| Fold_Ureal (N, Expr_Value_R (E1) + Small_Value (P_Type), Static); |
| |
| -- Modular integer case (wraps) |
| |
| elsif Is_Modular_Integer_Type (P_Type) then |
| Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static); |
| |
| -- Other scalar cases |
| |
| else |
| pragma Assert (Is_Scalar_Type (P_Type)); |
| |
| if Is_Enumeration_Type (P_Type) |
| and then Expr_Value (E1) = |
| Expr_Value (Type_High_Bound (P_Base_Type)) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "Succ of `&''Last`", |
| CE_Overflow_Check_Failed, |
| Ent => P_Base_Type, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| else |
| Fold_Uint (N, Expr_Value (E1) + 1, Static); |
| end if; |
| end if; |
| |
| ---------------- |
| -- Truncation -- |
| ---------------- |
| |
| when Attribute_Truncation => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Truncation (P_Base_Type, Expr_Value_R (E1)), |
| Static); |
| |
| ---------------- |
| -- Type_Class -- |
| ---------------- |
| |
| when Attribute_Type_Class => Type_Class : declare |
| Typ : constant Entity_Id := Underlying_Type (P_Base_Type); |
| Id : RE_Id; |
| |
| begin |
| if Is_Descendant_Of_Address (Typ) then |
| Id := RE_Type_Class_Address; |
| |
| elsif Is_Enumeration_Type (Typ) then |
| Id := RE_Type_Class_Enumeration; |
| |
| elsif Is_Integer_Type (Typ) then |
| Id := RE_Type_Class_Integer; |
| |
| elsif Is_Fixed_Point_Type (Typ) then |
| Id := RE_Type_Class_Fixed_Point; |
| |
| elsif Is_Floating_Point_Type (Typ) then |
| Id := RE_Type_Class_Floating_Point; |
| |
| elsif Is_Array_Type (Typ) then |
| Id := RE_Type_Class_Array; |
| |
| elsif Is_Record_Type (Typ) then |
| Id := RE_Type_Class_Record; |
| |
| elsif Is_Access_Type (Typ) then |
| Id := RE_Type_Class_Access; |
| |
| elsif Is_Task_Type (Typ) then |
| Id := RE_Type_Class_Task; |
| |
| -- We treat protected types like task types. It would make more |
| -- sense to have another enumeration value, but after all the |
| -- whole point of this feature is to be exactly DEC compatible, |
| -- and changing the type Type_Class would not meet this requirement. |
| |
| elsif Is_Protected_Type (Typ) then |
| Id := RE_Type_Class_Task; |
| |
| -- Not clear if there are any other possibilities, but if there |
| -- are, then we will treat them as the address case. |
| |
| else |
| Id := RE_Type_Class_Address; |
| end if; |
| |
| Rewrite (N, New_Occurrence_Of (RTE (Id), Loc)); |
| end Type_Class; |
| |
| ----------------------- |
| -- Unbiased_Rounding -- |
| ----------------------- |
| |
| when Attribute_Unbiased_Rounding => |
| Fold_Ureal |
| (N, |
| Eval_Fat.Unbiased_Rounding (P_Base_Type, Expr_Value_R (E1)), |
| Static); |
| |
| ------------------------- |
| -- Unconstrained_Array -- |
| ------------------------- |
| |
| when Attribute_Unconstrained_Array => Unconstrained_Array : declare |
| Typ : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| Rewrite (N, New_Occurrence_Of ( |
| Boolean_Literals ( |
| Is_Array_Type (P_Type) |
| and then not Is_Constrained (Typ)), Loc)); |
| |
| -- Analyze and resolve as boolean, note that this attribute is |
| -- a static attribute in GNAT. |
| |
| Analyze_And_Resolve (N, Standard_Boolean); |
| Static := True; |
| Set_Is_Static_Expression (N, True); |
| end Unconstrained_Array; |
| |
| -- Attribute Update is never static |
| |
| when Attribute_Update => |
| return; |
| |
| --------------- |
| -- VADS_Size -- |
| --------------- |
| |
| -- Processing is shared with Size |
| |
| --------- |
| -- Val -- |
| --------- |
| |
| when Attribute_Val => |
| if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type)) |
| or else |
| Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type)) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "Val expression out of range", |
| CE_Range_Check_Failed, |
| Warn => not Static); |
| |
| Check_Expressions; |
| return; |
| |
| else |
| Fold_Uint (N, Expr_Value (E1), Static); |
| end if; |
| |
| ---------------- |
| -- Value_Size -- |
| ---------------- |
| |
| -- The Value_Size attribute for a type returns the RM size of the type. |
| -- This an always be folded for scalar types, and can also be folded for |
| -- non-scalar types if the size is set. This is one of the places where |
| -- it is annoying that a size of zero means two things! |
| |
| when Attribute_Value_Size => Value_Size : declare |
| P_TypeA : constant Entity_Id := Underlying_Type (P_Type); |
| |
| begin |
| if Is_Scalar_Type (P_TypeA) or else RM_Size (P_TypeA) /= Uint_0 then |
| Fold_Uint (N, RM_Size (P_TypeA), Static); |
| end if; |
| end Value_Size; |
| |
| ------------- |
| -- Version -- |
| ------------- |
| |
| -- Version can never be static |
| |
| when Attribute_Version => |
| null; |
| |
| ---------------- |
| -- Wide_Image -- |
| ---------------- |
| |
| -- Wide_Image is a scalar attribute, but is never static, because it |
| -- is not a static function (having a non-scalar argument (RM 4.9(22)) |
| |
| when Attribute_Wide_Image => |
| null; |
| |
| --------------------- |
| -- Wide_Wide_Image -- |
| --------------------- |
| |
| -- Wide_Wide_Image is a scalar attribute but is never static, because it |
| -- is not a static function (having a non-scalar argument (RM 4.9(22)). |
| |
| when Attribute_Wide_Wide_Image => |
| null; |
| |
| --------------------- |
| -- Wide_Wide_Width -- |
| --------------------- |
| |
| -- Processing for Wide_Wide_Width is combined with Width |
| |
| ---------------- |
| -- Wide_Width -- |
| ---------------- |
| |
| -- Processing for Wide_Width is combined with Width |
| |
| ----------- |
| -- Width -- |
| ----------- |
| |
| -- This processing also handles the case of Wide_[Wide_]Width |
| |
| when Attribute_Width |
| | Attribute_Wide_Width |
| | Attribute_Wide_Wide_Width |
| => |
| if Compile_Time_Known_Bounds (P_Type) then |
| |
| -- Floating-point types |
| |
| if Is_Floating_Point_Type (P_Type) then |
| |
| -- Width is zero for a null range (RM 3.5 (38)) |
| |
| if Expr_Value_R (Type_High_Bound (P_Type)) < |
| Expr_Value_R (Type_Low_Bound (P_Type)) |
| then |
| Fold_Uint (N, Uint_0, Static); |
| |
| else |
| -- For floating-point, we have +N.dddE+nnn where length |
| -- of ddd is determined by type'Digits - 1, but is one |
| -- if Digits is one (RM 3.5 (33)). |
| |
| -- nnn is set to 2 for Short_Float and Float (32 bit |
| -- floats), and 3 for Long_Float and Long_Long_Float. |
| -- For machines where Long_Long_Float is the IEEE |
| -- extended precision type, the exponent takes 4 digits. |
| |
| declare |
| Len : Int := |
| Int'Max (2, UI_To_Int (Digits_Value (P_Type))); |
| |
| begin |
| if Esize (P_Type) <= 32 then |
| Len := Len + 6; |
| elsif Esize (P_Type) = 64 then |
| Len := Len + 7; |
| else |
| Len := Len + 8; |
| end if; |
| |
| Fold_Uint (N, UI_From_Int (Len), Static); |
| end; |
| end if; |
| |
| -- Fixed-point types |
| |
| elsif Is_Fixed_Point_Type (P_Type) then |
| |
| -- Width is zero for a null range (RM 3.5 (38)) |
| |
| if Expr_Value (Type_High_Bound (P_Type)) < |
| Expr_Value (Type_Low_Bound (P_Type)) |
| then |
| Fold_Uint (N, Uint_0, Static); |
| |
| -- The non-null case depends on the specific real type |
| |
| else |
| -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34)) |
| |
| Fold_Uint |
| (N, UI_From_Int (Fore_Value + 1) + Aft_Value (P_Type), |
| Static); |
| end if; |
| |
| -- Discrete types |
| |
| else |
| declare |
| R : constant Entity_Id := Root_Type (P_Type); |
| Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type)); |
| Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type)); |
| W : Nat; |
| Wt : Nat; |
| T : Uint; |
| L : Node_Id; |
| C : Character; |
| |
| begin |
| -- Empty ranges |
| |
| if Lo > Hi then |
| W := 0; |
| |
| -- Width for types derived from Standard.Character |
| -- and Standard.Wide_[Wide_]Character. |
| |
| elsif Is_Standard_Character_Type (P_Type) then |
| W := 0; |
| |
| -- Set W larger if needed |
| |
| for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop |
| |
| -- All wide characters look like Hex_hhhhhhhh |
| |
| if J > 255 then |
| |
| -- No need to compute this more than once |
| |
| exit; |
| |
| else |
| C := Character'Val (J); |
| |
| -- Test for all cases where Character'Image |
| -- yields an image that is longer than three |
| -- characters. First the cases of Reserved_xxx |
| -- names (length = 12). |
| |
| case C is |
| when Reserved_128 |
| | Reserved_129 |
| | Reserved_132 |
| | Reserved_153 |
| => |
| Wt := 12; |
| |
| when BS |
| | CR |
| | EM |
| | FF |
| | FS |
| | GS |
| | HT |
| | LF |
| | MW |
| | PM |
| | RI |
| | RS |
| | SI |
| | SO |
| | ST |
| | US |
| | VT |
| => |
| Wt := 2; |
| |
| when ACK |
| | APC |
| | BEL |
| | BPH |
| | CAN |
| | CCH |
| | CSI |
| | DC1 |
| | DC2 |
| | DC3 |
| | DC4 |
| | DCS |
| | DEL |
| | DLE |
| | ENQ |
| | EOT |
| | EPA |
| | ESA |
| | ESC |
| | ETB |
| | ETX |
| | HTJ |
| | HTS |
| | NAK |
| | NBH |
| | NEL |
| | NUL |
| | OSC |
| | PLD |
| | PLU |
| | PU1 |
| | PU2 |
| | SCI |
| | SOH |
| | SOS |
| | SPA |
| | SS2 |
| | SS3 |
| | SSA |
| | STS |
| | STX |
| | SUB |
| | SYN |
| | VTS |
| => |
| Wt := 3; |
| |
| when Space .. Tilde |
| | No_Break_Space .. LC_Y_Diaeresis |
| => |
| -- Special case of soft hyphen in Ada 2005 |
| |
| if C = Character'Val (16#AD#) |
| and then Ada_Version >= Ada_2005 |
| then |
| Wt := 11; |
| else |
| Wt := 3; |
| end if; |
| end case; |
| |
| W := Int'Max (W, Wt); |
| end if; |
| end loop; |
| |
| -- Width for types derived from Standard.Boolean |
| |
| elsif R = Standard_Boolean then |
| if Lo = 0 then |
| W := 5; -- FALSE |
| else |
| W := 4; -- TRUE |
| end if; |
| |
| -- Width for integer types |
| |
| elsif Is_Integer_Type (P_Type) then |
| T := UI_Max (abs Lo, abs Hi); |
| |
| W := 2; |
| while T >= 10 loop |
| W := W + 1; |
| T := T / 10; |
| end loop; |
| |
| -- User declared enum type with discard names |
| |
| elsif Discard_Names (R) then |
| |
| -- If range is null, result is zero, that has already |
| -- been dealt with, so what we need is the power of ten |
| -- that accommodates the Pos of the largest value, which |
| -- is the high bound of the range + one for the space. |
| |
| W := 1; |
| T := Hi; |
| while T /= 0 loop |
| T := T / 10; |
| W := W + 1; |
| end loop; |
| |
| -- Only remaining possibility is user declared enum type |
| -- with normal case of Discard_Names not active. |
| |
| else |
| pragma Assert (Is_Enumeration_Type (P_Type)); |
| |
| W := 0; |
| L := First_Literal (P_Type); |
| while Present (L) loop |
| |
| -- Only pay attention to in range characters |
| |
| if Lo <= Enumeration_Pos (L) |
| and then Enumeration_Pos (L) <= Hi |
| then |
| -- For Width case, use decoded name |
| |
| if Id = Attribute_Width then |
| Get_Decoded_Name_String (Chars (L)); |
| Wt := Nat (Name_Len); |
| |
| -- For Wide_[Wide_]Width, use encoded name, and |
| -- then adjust for the encoding. |
| |
| else |
| Get_Name_String (Chars (L)); |
| |
| -- Character literals are always of length 3 |
| |
| if Name_Buffer (1) = 'Q' then |
| Wt := 3; |
| |
| -- Otherwise loop to adjust for upper/wide chars |
| |
| else |
| Wt := Nat (Name_Len); |
| |
| for J in 1 .. Name_Len loop |
| if Name_Buffer (J) = 'U' then |
| Wt := Wt - 2; |
| elsif Name_Buffer (J) = 'W' then |
| Wt := Wt - 4; |
| end if; |
| end loop; |
| end if; |
| end if; |
| |
| W := Int'Max (W, Wt); |
| end if; |
| |
| Next_Literal (L); |
| end loop; |
| end if; |
| |
| Fold_Uint (N, UI_From_Int (W), Static); |
| end; |
| end if; |
| end if; |
| |
| -- The following attributes denote functions that cannot be folded |
| |
| when Attribute_From_Any |
| | Attribute_To_Any |
| | Attribute_TypeCode |
| => |
| null; |
| |
| -- The following attributes can never be folded, and furthermore we |
| -- should not even have entered the case statement for any of these. |
| -- Note that in some cases, the values have already been folded as |
| -- a result of the processing in Analyze_Attribute or earlier in |
| -- this procedure. |
| |
| when Attribute_Abort_Signal |
| | Attribute_Access |
| | Attribute_Address |
| | Attribute_Address_Size |
| | Attribute_Asm_Input |
| | Attribute_Asm_Output |
| | Attribute_Base |
| | Attribute_Bit_Order |
| | Attribute_Bit_Position |
| | Attribute_Callable |
| | Attribute_Caller |
| | Attribute_Class |
| | Attribute_Code_Address |
| | Attribute_Compiler_Version |
| | Attribute_Count |
| | Attribute_Default_Bit_Order |
| | Attribute_Default_Scalar_Storage_Order |
| | Attribute_Deref |
| | Attribute_Elaborated |
| | Attribute_Elab_Body |
| | Attribute_Elab_Spec |
| | Attribute_Elab_Subp_Body |
| | Attribute_Enabled |
| | Attribute_External_Tag |
| | Attribute_Fast_Math |
| | Attribute_First_Bit |
| | Attribute_Img |
| | Attribute_Input |
| | Attribute_Last_Bit |
| | Attribute_Library_Level |
| | Attribute_Maximum_Alignment |
| | Attribute_Old |
| | Attribute_Output |
| | Attribute_Partition_ID |
| | Attribute_Pool_Address |
| | Attribute_Position |
| | Attribute_Priority |
| | Attribute_Read |
| | Attribute_Result |
| | Attribute_Scalar_Storage_Order |
| | Attribute_Simple_Storage_Pool |
| | Attribute_Storage_Pool |
| | Attribute_Storage_Size |
| | Attribute_Storage_Unit |
| | Attribute_Stub_Type |
| | Attribute_System_Allocator_Alignment |
| | Attribute_Tag |
| | Attribute_Target_Name |
| | Attribute_Terminated |
| | Attribute_To_Address |
| | Attribute_Type_Key |
| | Attribute_Unchecked_Access |
| | Attribute_Universal_Literal_String |
| | Attribute_Unrestricted_Access |
| | Attribute_Valid |
| | Attribute_Valid_Scalars |
| | Attribute_Value |
| | Attribute_Wchar_T_Size |
| | Attribute_Wide_Value |
| | Attribute_Wide_Wide_Value |
| | Attribute_Word_Size |
| | Attribute_Write |
| => |
| raise Program_Error; |
| end case; |
| |
| -- At the end of the case, one more check. If we did a static evaluation |
| -- so that the result is now a literal, then set Is_Static_Expression |
| -- in the constant only if the prefix type is a static subtype. For |
| -- non-static subtypes, the folding is still OK, but not static. |
| |
| -- An exception is the GNAT attribute Constrained_Array which is |
| -- defined to be a static attribute in all cases. |
| |
| if Nkind_In (N, N_Integer_Literal, |
| N_Real_Literal, |
| N_Character_Literal, |
| N_String_Literal) |
| or else (Is_Entity_Name (N) |
| and then Ekind (Entity (N)) = E_Enumeration_Literal) |
| then |
| Set_Is_Static_Expression (N, Static); |
| |
| -- If this is still an attribute reference, then it has not been folded |
| -- and that means that its expressions are in a non-static context. |
| |
| elsif Nkind (N) = N_Attribute_Reference then |
| Check_Expressions; |
| |
| -- Note: the else case not covered here are odd cases where the |
| -- processing has transformed the attribute into something other |
| -- than a constant. Nothing more to do in such cases. |
| |
| else |
| null; |
| end if; |
| end Eval_Attribute; |
| |
| ------------------------------ |
| -- Is_Anonymous_Tagged_Base -- |
| ------------------------------ |
| |
| function Is_Anonymous_Tagged_Base |
| (Anon : Entity_Id; |
| Typ : Entity_Id) return Boolean |
| is |
| begin |
| return |
| Anon = Current_Scope |
| and then Is_Itype (Anon) |
| and then Associated_Node_For_Itype (Anon) = Parent (Typ); |
| end Is_Anonymous_Tagged_Base; |
| |
| -------------------------------- |
| -- Name_Implies_Lvalue_Prefix -- |
| -------------------------------- |
| |
| function Name_Implies_Lvalue_Prefix (Nam : Name_Id) return Boolean is |
| pragma Assert (Is_Attribute_Name (Nam)); |
| begin |
| return Attribute_Name_Implies_Lvalue_Prefix (Get_Attribute_Id (Nam)); |
| end Name_Implies_Lvalue_Prefix; |
| |
| ----------------------- |
| -- Resolve_Attribute -- |
| ----------------------- |
| |
| procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| P : constant Node_Id := Prefix (N); |
| Aname : constant Name_Id := Attribute_Name (N); |
| Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname); |
| Btyp : constant Entity_Id := Base_Type (Typ); |
| Des_Btyp : Entity_Id; |
| Index : Interp_Index; |
| It : Interp; |
| Nom_Subt : Entity_Id; |
| |
| procedure Accessibility_Message; |
| -- Error, or warning within an instance, if the static accessibility |
| -- rules of 3.10.2 are violated. |
| |
| function Declared_Within_Generic_Unit |
| (Entity : Entity_Id; |
| Generic_Unit : Node_Id) return Boolean; |
| -- Returns True if Declared_Entity is declared within the declarative |
| -- region of Generic_Unit; otherwise returns False. |
| |
| --------------------------- |
| -- Accessibility_Message -- |
| --------------------------- |
| |
| procedure Accessibility_Message is |
| Indic : Node_Id := Parent (Parent (N)); |
| |
| begin |
| -- In an instance, this is a runtime check, but one we |
| -- know will fail, so generate an appropriate warning. |
| |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_F |
| ("non-local pointer cannot point to local object<<", P); |
| Error_Msg_F ("\Program_Error [<<", P); |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, Typ); |
| return; |
| |
| else |
| Error_Msg_F ("non-local pointer cannot point to local object", P); |
| |
| -- Check for case where we have a missing access definition |
| |
| if Is_Record_Type (Current_Scope) |
| and then |
| Nkind_In (Parent (N), N_Discriminant_Association, |
| N_Index_Or_Discriminant_Constraint) |
| then |
| Indic := Parent (Parent (N)); |
| while Present (Indic) |
| and then Nkind (Indic) /= N_Subtype_Indication |
| loop |
| Indic := Parent (Indic); |
| end loop; |
| |
| if Present (Indic) then |
| Error_Msg_NE |
| ("\use an access definition for" & |
| " the access discriminant of&", |
| N, Entity (Subtype_Mark (Indic))); |
| end if; |
| end if; |
| end if; |
| end Accessibility_Message; |
| |
| ---------------------------------- |
| -- Declared_Within_Generic_Unit -- |
| ---------------------------------- |
| |
| function Declared_Within_Generic_Unit |
| (Entity : Entity_Id; |
| Generic_Unit : Node_Id) return Boolean |
| is |
| Generic_Encloser : Node_Id := Enclosing_Generic_Unit (Entity); |
| |
| begin |
| while Present (Generic_Encloser) loop |
| if Generic_Encloser = Generic_Unit then |
| return True; |
| end if; |
| |
| -- We have to step to the scope of the generic's entity, because |
| -- otherwise we'll just get back the same generic. |
| |
| Generic_Encloser := |
| Enclosing_Generic_Unit |
| (Scope (Defining_Entity (Generic_Encloser))); |
| end loop; |
| |
| return False; |
| end Declared_Within_Generic_Unit; |
| |
| -- Start of processing for Resolve_Attribute |
| |
| begin |
| -- If error during analysis, no point in continuing, except for array |
| -- types, where we get better recovery by using unconstrained indexes |
| -- than nothing at all (see Check_Array_Type). |
| |
| if Error_Posted (N) |
| and then Attr_Id /= Attribute_First |
| and then Attr_Id /= Attribute_Last |
| and then Attr_Id /= Attribute_Length |
| and then Attr_Id /= Attribute_Range |
| then |
| return; |
| end if; |
| |
| -- If attribute was universal type, reset to actual type |
| |
| if Etype (N) = Universal_Integer |
| or else Etype (N) = Universal_Real |
| then |
| Set_Etype (N, Typ); |
| end if; |
| |
| -- Remaining processing depends on attribute |
| |
| case Attr_Id is |
| |
| ------------ |
| -- Access -- |
| ------------ |
| |
| -- For access attributes, if the prefix denotes an entity, it is |
| -- interpreted as a name, never as a call. It may be overloaded, |
| -- in which case resolution uses the profile of the context type. |
| -- Otherwise prefix must be resolved. |
| |
| when Attribute_Access |
| | Attribute_Unchecked_Access |
| | Attribute_Unrestricted_Access |
| => |
| -- Note possible modification if we have a variable |
| |
| if Is_Variable (P) then |
| declare |
| PN : constant Node_Id := Parent (N); |
| Nm : Node_Id; |
| |
| Note : Boolean := True; |
| -- Skip this for the case of Unrestricted_Access occuring in |
| -- the context of a Valid check, since this otherwise leads |
| -- to a missed warning (the Valid check does not really |
| -- modify!) If this case, Note will be reset to False. |
| |
| -- Skip it as well if the type is an Acccess_To_Constant, |
| -- given that no use of the value can modify the prefix. |
| |
| begin |
| if Attr_Id = Attribute_Unrestricted_Access |
| and then Nkind (PN) = N_Function_Call |
| then |
| Nm := Name (PN); |
| |
| if Nkind (Nm) = N_Expanded_Name |
| and then Chars (Nm) = Name_Valid |
| and then Nkind (Prefix (Nm)) = N_Identifier |
| and then Chars (Prefix (Nm)) = Name_Attr_Long_Float |
| then |
| Note := False; |
| end if; |
| |
| elsif Is_Access_Constant (Typ) then |
| Note := False; |
| end if; |
| |
| if Note then |
| Note_Possible_Modification (P, Sure => False); |
| end if; |
| end; |
| end if; |
| |
| -- The following comes from a query concerning improper use of |
| -- universal_access in equality tests involving anonymous access |
| -- types. Another good reason for 'Ref, but for now disable the |
| -- test, which breaks several filed tests??? |
| |
| if Ekind (Typ) = E_Anonymous_Access_Type |
| and then Nkind_In (Parent (N), N_Op_Eq, N_Op_Ne) |
| and then False |
| then |
| Error_Msg_N ("need unique type to resolve 'Access", N); |
| Error_Msg_N ("\qualify attribute with some access type", N); |
| end if; |
| |
| -- Case where prefix is an entity name |
| |
| if Is_Entity_Name (P) then |
| |
| -- Deal with case where prefix itself is overloaded |
| |
| if Is_Overloaded (P) then |
| Get_First_Interp (P, Index, It); |
| while Present (It.Nam) loop |
| if Type_Conformant (Designated_Type (Typ), It.Nam) then |
| Set_Entity (P, It.Nam); |
| |
| -- The prefix is definitely NOT overloaded anymore at |
| -- this point, so we reset the Is_Overloaded flag to |
| -- avoid any confusion when reanalyzing the node. |
| |
| Set_Is_Overloaded (P, False); |
| Set_Is_Overloaded (N, False); |
| Generate_Reference (Entity (P), P); |
| exit; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| |
| -- If Prefix is a subprogram name, this reference freezes, |
| -- but not if within spec expression mode. The profile of |
| -- the subprogram is not frozen at this point. |
| |
| if not In_Spec_Expression then |
| Freeze_Before (N, Entity (P), Do_Freeze_Profile => False); |
| end if; |
| |
| -- If it is a type, there is nothing to resolve. |
| -- If it is a subprogram, do not freeze its profile. |
| -- If it is an object, complete its resolution. |
| |
| elsif Is_Overloadable (Entity (P)) then |
| if not In_Spec_Expression then |
| Freeze_Before (N, Entity (P), Do_Freeze_Profile => False); |
| end if; |
| |
| -- Nothing to do if prefix is a type name |
| |
| elsif Is_Type (Entity (P)) then |
| null; |
| |
| -- Otherwise non-overloaded other case, resolve the prefix |
| |
| else |
| Resolve (P); |
| end if; |
| |
| -- Some further error checks |
| |
| Error_Msg_Name_1 := Aname; |
| |
| if not Is_Entity_Name (P) then |
| null; |
| |
| elsif Is_Overloadable (Entity (P)) |
| and then Is_Abstract_Subprogram (Entity (P)) |
| then |
| Error_Msg_F ("prefix of % attribute cannot be abstract", P); |
| Set_Etype (N, Any_Type); |
| |
| elsif Ekind (Entity (P)) = E_Enumeration_Literal then |
| Error_Msg_F |
| ("prefix of % attribute cannot be enumeration literal", P); |
| Set_Etype (N, Any_Type); |
| |
| -- An attempt to take 'Access of a function that renames an |
| -- enumeration literal. Issue a specialized error message. |
| |
| elsif Ekind (Entity (P)) = E_Function |
| and then Present (Alias (Entity (P))) |
| and then Ekind (Alias (Entity (P))) = E_Enumeration_Literal |
| then |
| Error_Msg_F |
| ("prefix of % attribute cannot be function renaming " |
| & "an enumeration literal", P); |
| Set_Etype (N, Any_Type); |
| |
| elsif Convention (Entity (P)) = Convention_Intrinsic then |
| Error_Msg_F ("prefix of % attribute cannot be intrinsic", P); |
| Set_Etype (N, Any_Type); |
| end if; |
| |
| -- Assignments, return statements, components of aggregates, |
| -- generic instantiations will require convention checks if |
| -- the type is an access to subprogram. Given that there will |
| -- also be accessibility checks on those, this is where the |
| -- checks can eventually be centralized ??? |
| |
| if Ekind_In (Btyp, E_Access_Protected_Subprogram_Type, |
| E_Access_Subprogram_Type, |
| E_Anonymous_Access_Protected_Subprogram_Type, |
| E_Anonymous_Access_Subprogram_Type) |
| then |
| -- Deal with convention mismatch |
| |
| if Convention (Designated_Type (Btyp)) /= |
| Convention (Entity (P)) |
| then |
| -- The rule in 6.3.1 (8) deserves a special error |
| -- message. |
| |
| if Convention (Btyp) = Convention_Intrinsic |
| and then Nkind (Parent (N)) = N_Procedure_Call_Statement |
| and then Is_Entity_Name (Name (Parent (N))) |
| and then Inside_A_Generic |
| then |
| declare |
| Subp : constant Entity_Id := |
| Entity (Name (Parent (N))); |
| begin |
| if Convention (Subp) = Convention_Intrinsic then |
| Error_Msg_FE |
| ("?subprogram and its formal access " |
| & "parameters have convention Intrinsic", |
| Parent (N), Subp); |
| Error_Msg_N |
| ("actual cannot be access attribute", N); |
| end if; |
| end; |
| |
| else |
| Error_Msg_FE |
| ("subprogram & has wrong convention", P, Entity (P)); |
| Error_Msg_Sloc := Sloc (Btyp); |
| Error_Msg_FE ("\does not match & declared#", P, Btyp); |
| end if; |
| |
| if not Is_Itype (Btyp) |
| and then not Has_Convention_Pragma (Btyp) |
| then |
| Error_Msg_FE |
| ("\probable missing pragma Convention for &", |
| P, Btyp); |
| end if; |
| |
| else |
| Check_Subtype_Conformant |
| (New_Id => Entity (P), |
| Old_Id => Designated_Type (Btyp), |
| Err_Loc => P); |
| end if; |
| |
| if Attr_Id = Attribute_Unchecked_Access then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_F |
| ("attribute% cannot be applied to a subprogram", P); |
| |
| elsif Aname = Name_Unrestricted_Access then |
| null; -- Nothing to check |
| |
| -- Check the static accessibility rule of 3.10.2(32). |
| -- This rule also applies within the private part of an |
| -- instantiation. This rule does not apply to anonymous |
| -- access-to-subprogram types in access parameters. |
| |
| elsif Attr_Id = Attribute_Access |
| and then not In_Instance_Body |
| and then |
| (Ekind (Btyp) = E_Access_Subprogram_Type |
| or else Is_Local_Anonymous_Access (Btyp)) |
| and then Subprogram_Access_Level (Entity (P)) > |
| Type_Access_Level (Btyp) |
| then |
| Error_Msg_F |
| ("subprogram must not be deeper than access type", P); |
| |
| -- Check the restriction of 3.10.2(32) that disallows the |
| -- access attribute within a generic body when the ultimate |
| -- ancestor of the type of the attribute is declared outside |
| -- of the generic unit and the subprogram is declared within |
| -- that generic unit. This includes any such attribute that |
| -- occurs within the body of a generic unit that is a child |
| -- of the generic unit where the subprogram is declared. |
| |
| -- The rule also prohibits applying the attribute when the |
| -- access type is a generic formal access type (since the |
| -- level of the actual type is not known). This restriction |
| -- does not apply when the attribute type is an anonymous |
| -- access-to-subprogram type. Note that this check was |
| -- revised by AI-229, because the original Ada 95 rule |
| -- was too lax. The original rule only applied when the |
| -- subprogram was declared within the body of the generic, |
| -- which allowed the possibility of dangling references). |
| -- The rule was also too strict in some cases, in that it |
| -- didn't permit the access to be declared in the generic |
| -- spec, whereas the revised rule does (as long as it's not |
| -- a formal type). |
| |
| -- There are a couple of subtleties of the test for applying |
| -- the check that are worth noting. First, we only apply it |
| -- when the levels of the subprogram and access type are the |
| -- same (the case where the subprogram is statically deeper |
| -- was applied above, and the case where the type is deeper |
| -- is always safe). Second, we want the check to apply |
| -- within nested generic bodies and generic child unit |
| -- bodies, but not to apply to an attribute that appears in |
| -- the generic unit's specification. This is done by testing |
| -- that the attribute's innermost enclosing generic body is |
| -- not the same as the innermost generic body enclosing the |
| -- generic unit where the subprogram is declared (we don't |
| -- want the check to apply when the access attribute is in |
| -- the spec and there's some other generic body enclosing |
| -- generic). Finally, there's no point applying the check |
| -- when within an instance, because any violations will have |
| -- been caught by the compilation of the generic unit. |
| |
| -- We relax this check in Relaxed_RM_Semantics mode for |
| -- compatibility with legacy code for use by Ada source |
| -- code analyzers (e.g. CodePeer). |
| |
| elsif Attr_Id = Attribute_Access |
| and then not Relaxed_RM_Semantics |
| and then not In_Instance |
| and then Present (Enclosing_Generic_Unit (Entity (P))) |
| and then Present (Enclosing_Generic_Body (N)) |
| and then Enclosing_Generic_Body (N) /= |
| Enclosing_Generic_Body |
| (Enclosing_Generic_Unit (Entity (P))) |
| and then Subprogram_Access_Level (Entity (P)) = |
| Type_Access_Level (Btyp) |
| and then Ekind (Btyp) /= |
| E_Anonymous_Access_Subprogram_Type |
| and then Ekind (Btyp) /= |
| E_Anonymous_Access_Protected_Subprogram_Type |
| then |
| -- The attribute type's ultimate ancestor must be |
| -- declared within the same generic unit as the |
| -- subprogram is declared (including within another |
| -- nested generic unit). The error message is |
| -- specialized to say "ancestor" for the case where the |
| -- access type is not its own ancestor, since saying |
| -- simply "access type" would be very confusing. |
| |
| if not Declared_Within_Generic_Unit |
| (Root_Type (Btyp), |
| Enclosing_Generic_Unit (Entity (P))) |
| then |
| Error_Msg_N |
| ("''Access attribute not allowed in generic body", |
| N); |
| |
| if Root_Type (Btyp) = Btyp then |
| Error_Msg_NE |
| ("\because " & |
| "access type & is declared outside " & |
| "generic unit (RM 3.10.2(32))", N, Btyp); |
| else |
| Error_Msg_NE |
| ("\because ancestor of " & |
| "access type & is declared outside " & |
| "generic unit (RM 3.10.2(32))", N, Btyp); |
| end if; |
| |
| Error_Msg_NE |
| ("\move ''Access to private part, or " & |
| "(Ada 2005) use anonymous access type instead of &", |
| N, Btyp); |
| |
| -- If the ultimate ancestor of the attribute's type is |
| -- a formal type, then the attribute is illegal because |
| -- the actual type might be declared at a higher level. |
| -- The error message is specialized to say "ancestor" |
| -- for the case where the access type is not its own |
| -- ancestor, since saying simply "access type" would be |
| -- very confusing. |
| |
| elsif Is_Generic_Type (Root_Type (Btyp)) then |
| if Root_Type (Btyp) = Btyp then |
| Error_Msg_N |
| ("access type must not be a generic formal type", |
| N); |
| else |
| Error_Msg_N |
| ("ancestor access type must not be a generic " & |
| "formal type", N); |
| end if; |
| end if; |
| end if; |
| end if; |
| |
| -- If this is a renaming, an inherited operation, or a |
| -- subprogram instance, use the original entity. This may make |
| -- the node type-inconsistent, so this transformation can only |
| -- be done if the node will not be reanalyzed. In particular, |
| -- if it is within a default expression, the transformation |
| -- must be delayed until the default subprogram is created for |
| -- it, when the enclosing subprogram is frozen. |
| |
| if Is_Entity_Name (P) |
| and then Is_Overloadable (Entity (P)) |
| and then Present (Alias (Entity (P))) |
| and then Expander_Active |
| then |
| Rewrite (P, |
| New_Occurrence_Of (Alias (Entity (P)), Sloc (P))); |
| end if; |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then Is_Overloadable (Entity (Selector_Name (P))) |
| then |
| -- Protected operation. If operation is overloaded, must |
| -- disambiguate. Prefix that denotes protected object itself |
| -- is resolved with its own type. |
| |
| if Attr_Id = Attribute_Unchecked_Access then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_F |
| ("attribute% cannot be applied to protected operation", P); |
| end if; |
| |
| Resolve (Prefix (P)); |
| Generate_Reference (Entity (Selector_Name (P)), P); |
| |
| -- Implement check implied by 3.10.2 (18.1/2) : F.all'access is |
| -- statically illegal if F is an anonymous access to subprogram. |
| |
| elsif Nkind (P) = N_Explicit_Dereference |
| and then Is_Entity_Name (Prefix (P)) |
| and then Ekind (Etype (Entity (Prefix (P)))) = |
| E_Anonymous_Access_Subprogram_Type |
| then |
| Error_Msg_N ("anonymous access to subprogram " |
| & "has deeper accessibility than any master", P); |
| |
| elsif Is_Overloaded (P) then |
| |
| -- Use the designated type of the context to disambiguate |
| -- Note that this was not strictly conformant to Ada 95, |
| -- but was the implementation adopted by most Ada 95 compilers. |
| -- The use of the context type to resolve an Access attribute |
| -- reference is now mandated in AI-235 for Ada 2005. |
| |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (P, Index, It); |
| while Present (It.Typ) loop |
| if Covers (Designated_Type (Typ), It.Typ) then |
| Resolve (P, It.Typ); |
| exit; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| else |
| Resolve (P); |
| end if; |
| |
| -- X'Access is illegal if X denotes a constant and the access type |
| -- is access-to-variable. Same for 'Unchecked_Access. The rule |
| -- does not apply to 'Unrestricted_Access. If the reference is a |
| -- default-initialized aggregate component for a self-referential |
| -- type the reference is legal. |
| |
| if not (Ekind (Btyp) = E_Access_Subprogram_Type |
| or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type |
| or else (Is_Record_Type (Btyp) |
| and then |
| Present (Corresponding_Remote_Type (Btyp))) |
| or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type |
| or else Ekind (Btyp) |
| = E_Anonymous_Access_Protected_Subprogram_Type |
| or else Is_Access_Constant (Btyp) |
| or else Is_Variable (P) |
| or else Attr_Id = Attribute_Unrestricted_Access) |
| then |
| if Is_Entity_Name (P) |
| and then Is_Type (Entity (P)) |
| then |
| -- Legality of a self-reference through an access |
| -- attribute has been verified in Analyze_Access_Attribute. |
| |
| null; |
| |
| elsif Comes_From_Source (N) then |
| Error_Msg_F ("access-to-variable designates constant", P); |
| end if; |
| end if; |
| |
| Des_Btyp := Designated_Type (Btyp); |
| |
| if Ada_Version >= Ada_2005 |
| and then Is_Incomplete_Type (Des_Btyp) |
| then |
| -- Ada 2005 (AI-412): If the (sub)type is a limited view of an |
| -- imported entity, and the non-limited view is visible, make |
| -- use of it. If it is an incomplete subtype, use the base type |
| -- in any case. |
| |
| if From_Limited_With (Des_Btyp) |
| and then Present (Non_Limited_View (Des_Btyp)) |
| then |
| Des_Btyp := Non_Limited_View (Des_Btyp); |
| |
| elsif Ekind (Des_Btyp) = E_Incomplete_Subtype then |
| Des_Btyp := Etype (Des_Btyp); |
| end if; |
| end if; |
| |
| if (Attr_Id = Attribute_Access |
| or else |
| Attr_Id = Attribute_Unchecked_Access) |
| and then (Ekind (Btyp) = E_General_Access_Type |
| or else Ekind (Btyp) = E_Anonymous_Access_Type) |
| then |
| -- Ada 2005 (AI-230): Check the accessibility of anonymous |
| -- access types for stand-alone objects, record and array |
| -- components, and return objects. For a component definition |
| -- the level is the same of the enclosing composite type. |
| |
| if Ada_Version >= Ada_2005 |
| and then (Is_Local_Anonymous_Access (Btyp) |
| |
| -- Handle cases where Btyp is the anonymous access |
| -- type of an Ada 2012 stand-alone object. |
| |
| or else Nkind (Associated_Node_For_Itype (Btyp)) = |
| N_Object_Declaration) |
| and then |
| Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp) |
| and then Attr_Id = Attribute_Access |
| then |
| -- In an instance, this is a runtime check, but one we know |
| -- will fail, so generate an appropriate warning. As usual, |
| -- this kind of warning is an error in SPARK mode. |
| |
| if In_Instance_Body then |
| Error_Msg_Warn := SPARK_Mode /= On; |
| Error_Msg_F |
| ("non-local pointer cannot point to local object<<", P); |
| Error_Msg_F ("\Program_Error [<<", P); |
| |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Accessibility_Check_Failed)); |
| Set_Etype (N, Typ); |
| |
| else |
| Error_Msg_F |
| ("non-local pointer cannot point to local object", P); |
| end if; |
| end if; |
| |
| if Is_Dependent_Component_Of_Mutable_Object (P) then |
| Error_Msg_F |
| ("illegal attribute for discriminant-dependent component", |
| P); |
| end if; |
| |
| -- Check static matching rule of 3.10.2(27). Nominal subtype |
| -- of the prefix must statically match the designated type. |
| |
| Nom_Subt := Etype (P); |
| |
| if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then |
| Nom_Subt := Base_Type (Nom_Subt); |
| end if; |
| |
| if Is_Tagged_Type (Designated_Type (Typ)) then |
| |
| -- If the attribute is in the context of an access |
| -- parameter, then the prefix is allowed to be of |
| -- the class-wide type (by AI-127). |
| |
| if Ekind (Typ) = E_Anonymous_Access_Type then |
| if not Covers (Designated_Type (Typ), Nom_Subt) |
| and then not Covers (Nom_Subt, Designated_Type (Typ)) |
| then |
| declare |
| Desig : Entity_Id; |
| |
| begin |
| Desig := Designated_Type (Typ); |
| |
| if Is_Class_Wide_Type (Desig) then |
| Desig := Etype (Desig); |
| end if; |
| |
| if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then |
| null; |
| |
| else |
| Error_Msg_FE |
| ("type of prefix: & not compatible", |
| P, Nom_Subt); |
| Error_Msg_FE |
| ("\with &, the expected designated type", |
| P, Designated_Type (Typ)); |
| end if; |
| end; |
| end if; |
| |
| elsif not Covers (Designated_Type (Typ), Nom_Subt) |
| or else |
| (not Is_Class_Wide_Type (Designated_Type (Typ)) |
| and then Is_Class_Wide_Type (Nom_Subt)) |
| then |
| Error_Msg_FE |
| ("type of prefix: & is not covered", P, Nom_Subt); |
| Error_Msg_FE |
| ("\by &, the expected designated type" & |
| " (RM 3.10.2 (27))", P, Designated_Type (Typ)); |
| end if; |
| |
| if Is_Class_Wide_Type (Designated_Type (Typ)) |
| and then Has_Discriminants (Etype (Designated_Type (Typ))) |
| and then Is_Constrained (Etype (Designated_Type (Typ))) |
| and then Designated_Type (Typ) /= Nom_Subt |
| then |
| Apply_Discriminant_Check |
| (N, Etype (Designated_Type (Typ))); |
| end if; |
| |
| -- Ada 2005 (AI-363): Require static matching when designated |
| -- type has discriminants and a constrained partial view, since |
| -- in general objects of such types are mutable, so we can't |
| -- allow the access value to designate a constrained object |
| -- (because access values must be assumed to designate mutable |
| -- objects when designated type does not impose a constraint). |
| |
| elsif Subtypes_Statically_Match (Des_Btyp, Nom_Subt) then |
| null; |
| |
| elsif Has_Discriminants (Designated_Type (Typ)) |
| and then not Is_Constrained (Des_Btyp) |
| and then |
| (Ada_Version < Ada_2005 |
| or else |
| not Object_Type_Has_Constrained_Partial_View |
| (Typ => Designated_Type (Base_Type (Typ)), |
| Scop => Current_Scope)) |
| then |
| null; |
| |
| else |
| Error_Msg_F |
| ("object subtype must statically match " |
| & "designated subtype", P); |
| |
| if Is_Entity_Name (P) |
| and then Is_Array_Type (Designated_Type (Typ)) |
| then |
| declare |
| D : constant Node_Id := Declaration_Node (Entity (P)); |
| begin |
| Error_Msg_N |
| ("aliased object has explicit bounds??", D); |
| Error_Msg_N |
| ("\declare without bounds (and with explicit " |
| & "initialization)??", D); |
| Error_Msg_N |
| ("\for use with unconstrained access??", D); |
| end; |
| end if; |
| end if; |
| |
| -- Check the static accessibility rule of 3.10.2(28). Note that |
| -- this check is not performed for the case of an anonymous |
| -- access type, since the access attribute is always legal |
| -- in such a context. |
| |
| if Attr_Id /= Attribute_Unchecked_Access |
| and then Ekind (Btyp) = E_General_Access_Type |
| and then |
| Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp) |
| then |
| Accessibility_Message; |
| return; |
| end if; |
| end if; |
| |
| if Ekind_In (Btyp, E_Access_Protected_Subprogram_Type, |
| E_Anonymous_Access_Protected_Subprogram_Type) |
| then |
| if Is_Entity_Name (P) |
| and then not Is_Protected_Type (Scope (Entity (P))) |
| then |
| Error_Msg_F ("context requires a protected subprogram", P); |
| |
| -- Check accessibility of protected object against that of the |
| -- access type, but only on user code, because the expander |
| -- creates access references for handlers. If the context is an |
| -- anonymous_access_to_protected, there are no accessibility |
| -- checks either. Omit check entirely for Unrestricted_Access. |
| |
| elsif Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp) |
| and then Comes_From_Source (N) |
| and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type |
| and then Attr_Id /= Attribute_Unrestricted_Access |
| then |
| Accessibility_Message; |
| return; |
| |
| -- AI05-0225: If the context is not an access to protected |
| -- function, the prefix must be a variable, given that it may |
| -- be used subsequently in a protected call. |
| |
| elsif Nkind (P) = N_Selected_Component |
| and then not Is_Variable (Prefix (P)) |
| and then Ekind (Entity (Selector_Name (P))) /= E_Function |
| then |
| Error_Msg_N |
| ("target object of access to protected procedure " |
| & "must be variable", N); |
| |
| elsif Is_Entity_Name (P) then |
| Check_Internal_Protected_Use (N, Entity (P)); |
| end if; |
| |
| elsif Ekind_In (Btyp, E_Access_Subprogram_Type, |
| E_Anonymous_Access_Subprogram_Type) |
| and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type |
| then |
| Error_Msg_F ("context requires a non-protected subprogram", P); |
| end if; |
| |
| -- The context cannot be a pool-specific type, but this is a |
| -- legality rule, not a resolution rule, so it must be checked |
| -- separately, after possibly disambiguation (see AI-245). |
| |
| if Ekind (Btyp) = E_Access_Type |
| and then Attr_Id /= Attribute_Unrestricted_Access |
| then |
| Wrong_Type (N, Typ); |
| end if; |
| |
| -- The context may be a constrained access type (however ill- |
| -- advised such subtypes might be) so in order to generate a |
| -- constraint check we need to set the type of the attribute |
| -- reference to the base type of the context. |
| |
| Set_Etype (N, Btyp); |
| |
| -- Check for incorrect atomic/volatile reference (RM C.6(12)) |
| |
| if Attr_Id /= Attribute_Unrestricted_Access then |
| if Is_Atomic_Object (P) |
| and then not Is_Atomic (Designated_Type (Typ)) |
| then |
| Error_Msg_F |
| ("access to atomic object cannot yield access-to-" & |
| "non-atomic type", P); |
| |
| elsif Is_Volatile_Object (P) |
| and then not Is_Volatile (Designated_Type (Typ)) |
| then |
| Error_Msg_F |
| ("access to volatile object cannot yield access-to-" & |
| "non-volatile type", P); |
| end if; |
| end if; |
| |
| -- Check for aliased view. We allow a nonaliased prefix when in |
| -- an instance because the prefix may have been a tagged formal |
| -- object, which is defined to be aliased even when the actual |
| -- might not be (other instance cases will have been caught in |
| -- the generic). Similarly, within an inlined body we know that |
| -- the attribute is legal in the original subprogram, therefore |
| -- legal in the expansion. |
| |
| if not (Is_Entity_Name (P) |
| and then Is_Overloadable (Entity (P))) |
| and then not (Nkind (P) = N_Selected_Component |
| and then |
| Is_Overloadable (Entity (Selector_Name (P)))) |
| and then not Is_Aliased_View (Original_Node (P)) |
| and then not In_Instance |
| and then not In_Inlined_Body |
| and then Comes_From_Source (N) |
| then |
| -- Here we have a non-aliased view. This is illegal unless we |
| -- have the case of Unrestricted_Access, where for now we allow |
| -- this (we will reject later if expected type is access to an |
| -- unconstrained array with a thin pointer). |
| |
| -- No need for an error message on a generated access reference |
| -- for the controlling argument in a dispatching call: error |
| -- will be reported when resolving the call. |
| |
| if Attr_Id /= Attribute_Unrestricted_Access then |
| Error_Msg_N ("prefix of % attribute must be aliased", P); |
| |
| -- Check for unrestricted access where expected type is a thin |
| -- pointer to an unconstrained array. |
| |
| elsif Has_Size_Clause (Typ) |
| and then RM_Size (Typ) = System_Address_Size |
| then |
| declare |
| DT : constant Entity_Id := Designated_Type (Typ); |
| begin |
| if Is_Array_Type (DT) |
| and then not Is_Constrained (DT) |
| then |
| Error_Msg_N |
| ("illegal use of Unrestricted_Access attribute", P); |
| Error_Msg_N |
| ("\attempt to generate thin pointer to unaliased " |
| & "object", P); |
| end if; |
| end; |
| end if; |
| end if; |
| |
| -- Mark that address of entity is taken in case of |
| -- 'Unrestricted_Access or in case of a subprogram. |
| |
| if Is_Entity_Name (P) |
| and then (Attr_Id = Attribute_Unrestricted_Access |
| or else Is_Subprogram (Entity (P))) |
| then |
| Set_Address_Taken (Entity (P)); |
| end if; |
| |
| -- Deal with possible elaboration check |
| |
| if Is_Entity_Name (P) and then Is_Subprogram (Entity (P)) then |
| declare |
| Subp_Id : constant Entity_Id := Entity (P); |
| Scop : constant Entity_Id := Scope (Subp_Id); |
| Subp_Decl : constant Node_Id := |
| Unit_Declaration_Node (Subp_Id); |
| Flag_Id : Entity_Id; |
| Subp_Body : Node_Id; |
| |
| -- If the access has been taken and the body of the subprogram |
| -- has not been see yet, indirect calls must be protected with |
| -- elaboration checks. We have the proper elaboration machinery |
| -- for subprograms declared in packages, but within a block or |
| -- a subprogram the body will appear in the same declarative |
| -- part, and we must insert a check in the eventual body itself |
| -- using the elaboration flag that we generate now. The check |
| -- is then inserted when the body is expanded. This processing |
| -- is not needed for a stand alone expression function because |
| -- the internally generated spec and body are always inserted |
| -- as a pair in the same declarative list. |
| |
| begin |
| if Expander_Active |
| and then Comes_From_Source (Subp_Id) |
| and then Comes_From_Source (N) |
| and then In_Open_Scopes (Scop) |
| and then Ekind_In (Scop, E_Block, E_Procedure, E_Function) |
| and then not Has_Completion (Subp_Id) |
| and then No (Elaboration_Entity (Subp_Id)) |
| and then Nkind (Subp_Decl) = N_Subprogram_Declaration |
| and then Nkind (Original_Node (Subp_Decl)) /= |
| N_Expression_Function |
| then |
| -- Create elaboration variable for it |
| |
| Flag_Id := Make_Temporary (Loc, 'E'); |
| Set_Elaboration_Entity (Subp_Id, Flag_Id); |
| Set_Is_Frozen (Flag_Id); |
| |
| -- Insert declaration for flag after subprogram |
| -- declaration. Note that attribute reference may |
| -- appear within a nested scope. |
| |
| Insert_After_And_Analyze (Subp_Decl, |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Flag_Id, |
| Object_Definition => |
| New_Occurrence_Of (Standard_Short_Integer, Loc), |
| Expression => |
| Make_Integer_Literal (Loc, Uint_0))); |
| |
| -- The above sets the Scope of the flag entity to the |
| -- current scope, in which the attribute appears, but |
| -- the flag declaration has been inserted after that |
| -- of Subp_Id, so the scope of the flag is the same as |
| -- that of Subp_Id. This is relevant when unnesting, |
| -- where processing depends on correct scope setting. |
| |
| Set_Scope (Flag_Id, Scop); |
| end if; |
| |
| -- Taking the 'Access of an expression function freezes its |
| -- expression (RM 13.14 10.3/3). This does not apply to an |
| -- expression function that acts as a completion because the |
| -- generated body is immediately analyzed and the expression |
| -- is automatically frozen. |
| |
| if Is_Expression_Function (Subp_Id) |
| and then Present (Corresponding_Body (Subp_Decl)) |
| then |
| Subp_Body := |
| Unit_Declaration_Node (Corresponding_Body (Subp_Decl)); |
| |
| -- The body has already been analyzed when the expression |
| -- function acts as a completion. |
| |
| if Analyzed (Subp_Body) then |
| null; |
| |
| -- Attribute 'Access may appear within the generated body |
| -- of the expression function subject to the attribute: |
| |
| -- function F is (... F'Access ...); |
| |
| -- If the expression function is on the scope stack, then |
| -- the body is currently being analyzed. Do not reanalyze |
| -- it because this will lead to infinite recursion. |
| |
| elsif In_Open_Scopes (Subp_Id) then |
| null; |
| |
| -- If reference to the expression function appears in an |
| -- inner scope, for example as an actual in an instance, |
| -- this is not a freeze point either. |
| |
| elsif Scope (Subp_Id) /= Current_Scope then |
| null; |
| |
| -- Analyze the body of the expression function to freeze |
| -- the expression. This takes care of the case where the |
| -- 'Access is part of dispatch table initialization and |
| -- the generated body of the expression function has not |
| -- been analyzed yet. |
| |
| else |
| Analyze (Subp_Body); |
| end if; |
| end if; |
| end; |
| end if; |
| |
| ------------- |
| -- Address -- |
| ------------- |
| |
| -- Deal with resolving the type for Address attribute, overloading |
| -- is not permitted here, since there is no context to resolve it. |
| |
| when Attribute_Address |
| | Attribute_Code_Address |
| => |
| -- To be safe, assume that if the address of a variable is taken, |
| -- it may be modified via this address, so note modification. |
| |
| if Is_Variable (P) then |
| Note_Possible_Modification (P, Sure => False); |
| end if; |
| |
| if Nkind (P) in N_Subexpr |
| and then Is_Overloaded (P) |
| then |
| Get_First_Interp (P, Index, It); |
| Get_Next_Interp (Index, It); |
| |
| if Present (It.Nam) then |
| Error_Msg_Name_1 := Aname; |
| Error_Msg_F |
| ("prefix of % attribute cannot be overloaded", P); |
| end if; |
| end if; |
| |
| if not Is_Entity_Name (P) |
| or else not Is_Overloadable (Entity (P)) |
| then |
| if not Is_Task_Type (Etype (P)) |
| or else Nkind (P) = N_Explicit_Dereference |
| then |
| Resolve (P); |
| end if; |
| end if; |
| |
| -- If this is the name of a derived subprogram, or that of a |
| -- generic actual, the address is that of the original entity. |
| |
| if Is_Entity_Name (P) |
| and then Is_Overloadable (Entity (P)) |
| and then Present (Alias (Entity (P))) |
| then |
| Rewrite (P, |
| New_Occurrence_Of (Alias (Entity (P)), Sloc (P))); |
| end if; |
| |
| if Is_Entity_Name (P) then |
| Set_Address_Taken (Entity (P)); |
| end if; |
| |
| if Nkind (P) = N_Slice then |
| |
| -- Arr (X .. Y)'address is identical to Arr (X)'address, |
| -- even if the array is packed and the slice itself is not |
| -- addressable. Transform the prefix into an indexed component. |
| |
| -- Note that the transformation is safe only if we know that |
| -- the slice is non-null. That is because a null slice can have |
| -- an out of bounds index value. |
| |
| -- Right now, gigi blows up if given 'Address on a slice as a |
| -- result of some incorrect freeze nodes generated by the front |
| -- end, and this covers up that bug in one case, but the bug is |
| -- likely still there in the cases not handled by this code ??? |
| |
| -- It's not clear what 'Address *should* return for a null |
| -- slice with out of bounds indexes, this might be worth an ARG |
| -- discussion ??? |
| |
| -- One approach would be to do a length check unconditionally, |
| -- and then do the transformation below unconditionally, but |
| -- analyze with checks off, avoiding the problem of the out of |
| -- bounds index. This approach would interpret the address of |
| -- an out of bounds null slice as being the address where the |
| -- array element would be if there was one, which is probably |
| -- as reasonable an interpretation as any ??? |
| |
| declare |
| Loc : constant Source_Ptr := Sloc (P); |
| D : constant Node_Id := Discrete_Range (P); |
| Lo : Node_Id; |
| |
| begin |
| if Is_Entity_Name (D) |
| and then |
| Not_Null_Range |
| (Type_Low_Bound (Entity (D)), |
| Type_High_Bound (Entity (D))) |
| then |
| Lo := |
| Make_Attribute_Reference (Loc, |
| Prefix => (New_Occurrence_Of (Entity (D), Loc)), |
| Attribute_Name => Name_First); |
| |
| elsif Nkind (D) = N_Range |
| and then Not_Null_Range (Low_Bound (D), High_Bound (D)) |
| then |
| Lo := Low_Bound (D); |
| |
| else |
| Lo := Empty; |
| end if; |
| |
| if Present (Lo) then |
| Rewrite (P, |
| Make_Indexed_Component (Loc, |
| Prefix => Relocate_Node (Prefix (P)), |
| Expressions => New_List (Lo))); |
| |
| Analyze_And_Resolve (P); |
| end if; |
| end; |
| end if; |
| |
| ------------------ |
| -- Body_Version -- |
| ------------------ |
| |
| -- Prefix of Body_Version attribute can be a subprogram name which |
| -- must not be resolved, since this is not a call. |
| |
| when Attribute_Body_Version => |
| null; |
| |
| ------------ |
| -- Caller -- |
| ------------ |
| |
| -- Prefix of Caller attribute is an entry name which must not |
| -- be resolved, since this is definitely not an entry call. |
| |
| when Attribute_Caller => |
| null; |
| |
| ------------------ |
| -- Code_Address -- |
| ------------------ |
| |
| -- Shares processing with Address attribute |
| |
| ----------- |
| -- Count -- |
| ----------- |
| |
| -- If the prefix of the Count attribute is an entry name it must not |
| -- be resolved, since this is definitely not an entry call. However, |
| -- if it is an element of an entry family, the index itself may |
| -- have to be resolved because it can be a general expression. |
| |
| when Attribute_Count => |
| if Nkind (P) = N_Indexed_Component |
| and then Is_Entity_Name (Prefix (P)) |
| then |
| declare |
| Indx : constant Node_Id := First (Expressions (P)); |
| Fam : constant Entity_Id := Entity (Prefix (P)); |
| begin |
| Resolve (Indx, Entry_Index_Type (Fam)); |
| Apply_Range_Check (Indx, Entry_Index_Type (Fam)); |
| end; |
| end if; |
| |
| ---------------- |
| -- Elaborated -- |
| ---------------- |
| |
| -- Prefix of the Elaborated attribute is a subprogram name which |
| -- must not be resolved, since this is definitely not a call. Note |
| -- that it is a library unit, so it cannot be overloaded here. |
| |
| when Attribute_Elaborated => |
| null; |
| |
| ------------- |
| -- Enabled -- |
| ------------- |
| |
| -- Prefix of Enabled attribute is a check name, which must be treated |
| -- specially and not touched by Resolve. |
| |
| when Attribute_Enabled => |
| null; |
| |
| ---------------- |
| -- Loop_Entry -- |
| ---------------- |
| |
| -- Do not resolve the prefix of Loop_Entry, instead wait until the |
| -- attribute has been expanded (see Expand_Loop_Entry_Attributes). |
| -- The delay ensures that any generated checks or temporaries are |
| -- inserted before the relocated prefix. |
| |
| when Attribute_Loop_Entry => |
| null; |
| |
| -------------------- |
| -- Mechanism_Code -- |
| -------------------- |
| |
| -- Prefix of the Mechanism_Code attribute is a function name |
| -- which must not be resolved. Should we check for overloaded ??? |
| |
| when Attribute_Mechanism_Code => |
| null; |
| |
| ------------------ |
| -- Partition_ID -- |
| ------------------ |
| |
| -- Most processing is done in sem_dist, after determining the |
| -- context type. Node is rewritten as a conversion to a runtime call. |
| |
| when Attribute_Partition_ID => |
| Process_Partition_Id (N); |
| return; |
| |
| ------------------ |
| -- Pool_Address -- |
| ------------------ |
| |
| when Attribute_Pool_Address => |
| Resolve (P); |
| |
| ----------- |
| -- Range -- |
| ----------- |
| |
| -- We replace the Range attribute node with a range expression whose |
| -- bounds are the 'First and 'Last attributes applied to the same |
| -- prefix. The reason that we do this transformation here instead of |
| -- in the expander is that it simplifies other parts of the semantic |
| -- analysis which assume that the Range has been replaced; thus it |
| -- must be done even when in semantic-only mode (note that the RM |
| -- specifically mentions this equivalence, we take care that the |
| -- prefix is only evaluated once). |
| |
| when Attribute_Range => Range_Attribute : declare |
| Dims : List_Id; |
| HB : Node_Id; |
| LB : Node_Id; |
| |
| begin |
| if not Is_Entity_Name (P) or else not Is_Type (Entity (P)) then |
| Resolve (P); |
| end if; |
| |
| Dims := Expressions (N); |
| |
| HB := |
| Make_Attribute_Reference (Loc, |
| Prefix => Duplicate_Subexpr (P, Name_Req => True), |
| Attribute_Name => Name_Last, |
| Expressions => Dims); |
| |
| LB := |
| Make_Attribute_Reference (Loc, |
| Prefix => P, |
| Attribute_Name => Name_First, |
| Expressions => (Dims)); |
| |
| -- Do not share the dimension indicator, if present. Even though |
| -- it is a static constant, its source location may be modified |
| -- when printing expanded code and node sharing will lead to chaos |
| -- in Sprint. |
| |
| if Present (Dims) then |
| Set_Expressions (LB, New_List (New_Copy_Tree (First (Dims)))); |
| end if; |
| |
| -- If the original was marked as Must_Not_Freeze (see code in |
| -- Sem_Ch3.Make_Index), then make sure the rewriting does not |
| -- freeze either. |
| |
| if Must_Not_Freeze (N) then |
| Set_Must_Not_Freeze (HB); |
| Set_Must_Not_Freeze (LB); |
| Set_Must_Not_Freeze (Prefix (HB)); |
| Set_Must_Not_Freeze (Prefix (LB)); |
| end if; |
| |
| if Raises_Constraint_Error (Prefix (N)) then |
| |
| -- Preserve Sloc of prefix in the new bounds, so that the |
| -- posted warning can be removed if we are within unreachable |
| -- code. |
| |
| Set_Sloc (LB, Sloc (Prefix (N))); |
| Set_Sloc (HB, Sloc (Prefix (N))); |
| end if; |
| |
| Rewrite (N, Make_Range (Loc, LB, HB)); |
| Analyze_And_Resolve (N, Typ); |
| |
| -- Ensure that the expanded range does not have side effects |
| |
| Force_Evaluation (LB); |
| Force_Evaluation (HB); |
| |
| -- Normally after resolving attribute nodes, Eval_Attribute |
| -- is called to do any possible static evaluation of the node. |
| -- However, here since the Range attribute has just been |
| -- transformed into a range expression it is no longer an |
| -- attribute node and therefore the call needs to be avoided |
| -- and is accomplished by simply returning from the procedure. |
| |
| return; |
| end Range_Attribute; |
| |
| ------------ |
| -- Result -- |
| ------------ |
| |
| -- We will only come here during the prescan of a spec expression |
| -- containing a Result attribute. In that case the proper Etype has |
| -- already been set, and nothing more needs to be done here. |
| |
| when Attribute_Result => |
| null; |
| |
| ---------------------- |
| -- Unchecked_Access -- |
| ---------------------- |
| |
| -- Processing is shared with Access |
| |
| ------------------------- |
| -- Unrestricted_Access -- |
| ------------------------- |
| |
| -- Processing is shared with Access |
| |
| ------------ |
| -- Update -- |
| ------------ |
| |
| -- Resolve aggregate components in component associations |
| |
| when Attribute_Update => Update : declare |
| Aggr : constant Node_Id := First (Expressions (N)); |
| Typ : constant Entity_Id := Etype (Prefix (N)); |
| Assoc : Node_Id; |
| Comp : Node_Id; |
| Expr : Node_Id; |
| |
| begin |
| -- Set the Etype of the aggregate to that of the prefix, even |
| -- though the aggregate may not be a proper representation of a |
| -- value of the type (missing or duplicated associations, etc.) |
| -- Complete resolution of the prefix. Note that in Ada 2012 it |
| -- can be a qualified expression that is e.g. an aggregate. |
| |
| Set_Etype (Aggr, Typ); |
| Resolve (Prefix (N), Typ); |
| |
| -- For an array type, resolve expressions with the component type |
| -- of the array, and apply constraint checks when needed. |
| |
| if Is_Array_Type (Typ) then |
| Assoc := First (Component_Associations (Aggr)); |
| while Present (Assoc) loop |
| Expr := Expression (Assoc); |
| Resolve (Expr, Component_Type (Typ)); |
| |
| -- For scalar array components set Do_Range_Check when |
| -- needed. Constraint checking on non-scalar components |
| -- is done in Aggregate_Constraint_Checks, but only if |
| -- full analysis is enabled. These flags are not set in |
| -- the front-end in GnatProve mode. |
| |
| if Is_Scalar_Type (Component_Type (Typ)) |
| and then not Is_OK_Static_Expression (Expr) |
| and then not Range_Checks_Suppressed (Component_Type (Typ)) |
| then |
| if Is_Entity_Name (Expr) |
| and then Etype (Expr) = Component_Type (Typ) |
| then |
| null; |
| |
| else |
| Set_Do_Range_Check (Expr); |
| end if; |
| end if; |
| |
| -- The choices in the association are static constants, |
| -- or static aggregates each of whose components belongs |
| -- to the proper index type. However, they must also |
| -- belong to the index subtype (s) of the prefix, which |
| -- may be a subtype (e.g. given by a slice). |
| |
| -- Choices may also be identifiers with no staticness |
| -- requirements, in which case they must resolve to the |
| -- index type. |
| |
| declare |
| C : Node_Id; |
| C_E : Node_Id; |
| Indx : Node_Id; |
| |
| begin |
| C := First (Choices (Assoc)); |
| while Present (C) loop |
| Indx := First_Index (Etype (Prefix (N))); |
| |
| if Nkind (C) /= N_Aggregate then |
| Analyze_And_Resolve (C, Etype (Indx)); |
| Apply_Constraint_Check (C, Etype (Indx)); |
| Check_Non_Static_Context (C); |
| |
| else |
| C_E := First (Expressions (C)); |
| while Present (C_E) loop |
| Analyze_And_Resolve (C_E, Etype (Indx)); |
| Apply_Constraint_Check (C_E, Etype (Indx)); |
| Check_Non_Static_Context (C_E); |
| |
| Next (C_E); |
| Next_Index (Indx); |
| end loop; |
| end if; |
| |
| Next (C); |
| end loop; |
| end; |
| |
| Next (Assoc); |
| end loop; |
| |
| -- For a record type, use type of each component, which is |
| -- recorded during analysis. |
| |
| else |
| Assoc := First (Component_Associations (Aggr)); |
| while Present (Assoc) loop |
| Comp := First (Choices (Assoc)); |
| Expr := Expression (Assoc); |
| |
| if Nkind (Comp) /= N_Others_Choice |
| and then not Error_Posted (Comp) |
| then |
| Resolve (Expr, Etype (Entity (Comp))); |
| |
| if Is_Scalar_Type (Etype (Entity (Comp))) |
| and then not Is_OK_Static_Expression (Expr) |
| and then not Range_Checks_Suppressed |
| (Etype (Entity (Comp))) |
| then |
| Set_Do_Range_Check (Expr); |
| end if; |
| end if; |
| |
| Next (Assoc); |
| end loop; |
| end if; |
| end Update; |
| |
| --------- |
| -- Val -- |
| --------- |
| |
| -- Apply range check. Note that we did not do this during the |
| -- analysis phase, since we wanted Eval_Attribute to have a |
| -- chance at finding an illegal out of range value. |
| |
| when Attribute_Val => |
| |
| -- Note that we do our own Eval_Attribute call here rather than |
| -- use the common one, because we need to do processing after |
| -- the call, as per above comment. |
| |
| Eval_Attribute (N); |
| |
| -- Eval_Attribute may replace the node with a raise CE, or |
| -- fold it to a constant. Obviously we only apply a scalar |
| -- range check if this did not happen. |
| |
| if Nkind (N) = N_Attribute_Reference |
| and then Attribute_Name (N) = Name_Val |
| then |
| Apply_Scalar_Range_Check (First (Expressions (N)), Btyp); |
| end if; |
| |
| return; |
| |
| ------------- |
| -- Version -- |
| ------------- |
| |
| -- Prefix of Version attribute can be a subprogram name which |
| -- must not be resolved, since this is not a call. |
| |
| when Attribute_Version => |
| null; |
| |
| ---------------------- |
| -- Other Attributes -- |
| ---------------------- |
| |
| -- For other attributes, resolve prefix unless it is a type. If |
| -- the attribute reference itself is a type name ('Base and 'Class) |
| -- then this is only legal within a task or protected record. |
| |
| when others => |
| if not Is_Entity_Name (P) or else not Is_Type (Entity (P)) then |
| Resolve (P); |
| end if; |
| |
| -- If the attribute reference itself is a type name ('Base, |
| -- 'Class) then this is only legal within a task or protected |
| -- record. What is this all about ??? |
| |
| if Is_Entity_Name (N) and then Is_Type (Entity (N)) then |
| if Is_Concurrent_Type (Entity (N)) |
| and then In_Open_Scopes (Entity (P)) |
| then |
| null; |
| else |
| Error_Msg_N |
| ("invalid use of subtype name in expression or call", N); |
| end if; |
| end if; |
| |
| -- For attributes whose argument may be a string, complete |
| -- resolution of argument now. This avoids premature expansion |
| -- (and the creation of transient scopes) before the attribute |
| -- reference is resolved. |
| |
| case Attr_Id is |
| when Attribute_Value => |
| Resolve (First (Expressions (N)), Standard_String); |
| |
| when Attribute_Wide_Value => |
| Resolve (First (Expressions (N)), Standard_Wide_String); |
| |
| when Attribute_Wide_Wide_Value => |
| Resolve (First (Expressions (N)), Standard_Wide_Wide_String); |
| |
| when others => null; |
| end case; |
| |
| -- If the prefix of the attribute is a class-wide type then it |
| -- will be expanded into a dispatching call to a predefined |
| -- primitive. Therefore we must check for potential violation |
| -- of such restriction. |
| |
| if Is_Class_Wide_Type (Etype (P)) then |
| Check_Restriction (No_Dispatching_Calls, N); |
| end if; |
| end case; |
| |
| -- Mark use clauses of the original prefix if the attribute is applied |
| -- to an entity. |
| |
| if Nkind (Original_Node (P)) in N_Has_Entity |
| and then Present (Entity (Original_Node (P))) |
| then |
| Mark_Use_Clauses (Original_Node (P)); |
| end if; |
| |
| -- Normally the Freezing is done by Resolve but sometimes the Prefix |
| -- is not resolved, in which case the freezing must be done now. |
| |
| -- For an elaboration check on a subprogram, we do not freeze its type. |
| -- It may be declared in an unrelated scope, in particular in the case |
| -- of a generic function whose type may remain unelaborated. |
| |
| if Attr_Id = Attribute_Elaborated then |
| null; |
| |
| -- Should this be restricted to Expander_Active??? |
| |
| else |
| Freeze_Expression (P); |
| end if; |
| |
| -- Finally perform static evaluation on the attribute reference |
| |
| Analyze_Dimension (N); |
| Eval_Attribute (N); |
| end Resolve_Attribute; |
| |
| ------------------------ |
| -- Set_Boolean_Result -- |
| ------------------------ |
| |
| procedure Set_Boolean_Result (N : Node_Id; B : Boolean) is |
| Loc : constant Source_Ptr := Sloc (N); |
| begin |
| if B then |
| Rewrite (N, New_Occurrence_Of (Standard_True, Loc)); |
| else |
| Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); |
| end if; |
| end Set_Boolean_Result; |
| |
| ------------------------------- |
| -- Statically_Denotes_Object -- |
| ------------------------------- |
| |
| function Statically_Denotes_Object (N : Node_Id) return Boolean is |
| Indx : Node_Id; |
| |
| begin |
| if Is_Entity_Name (N) then |
| return True; |
| |
| elsif Nkind (N) = N_Selected_Component |
| and then Statically_Denotes_Object (Prefix (N)) |
| and then Present (Entity (Selector_Name (N))) |
| then |
| declare |
| Sel_Id : constant Entity_Id := Entity (Selector_Name (N)); |
| Comp_Decl : constant Node_Id := Parent (Sel_Id); |
| |
| begin |
| if Depends_On_Discriminant (Sel_Id) then |
| return False; |
| |
| elsif Nkind (Parent (Parent (Comp_Decl))) = N_Variant then |
| return False; |
| |
| else |
| return True; |
| end if; |
| end; |
| |
| elsif Nkind (N) = N_Indexed_Component |
| and then Statically_Denotes_Object (Prefix (N)) |
| and then Is_Constrained (Etype (Prefix (N))) |
| then |
| Indx := First (Expressions (N)); |
| while Present (Indx) loop |
| if not Compile_Time_Known_Value (Indx) |
| or else Do_Range_Check (Indx) |
| then |
| return False; |
| end if; |
| |
| Next (Indx); |
| end loop; |
| |
| return True; |
| |
| else |
| return False; |
| end if; |
| end Statically_Denotes_Object; |
| |
| -------------------------------- |
| -- Stream_Attribute_Available -- |
| -------------------------------- |
| |
| function Stream_Attribute_Available |
| (Typ : Entity_Id; |
| Nam : TSS_Name_Type; |
| Partial_View : Node_Id := Empty) return Boolean |
| is |
| Etyp : Entity_Id := Typ; |
| |
| -- Start of processing for Stream_Attribute_Available |
| |
| begin |
| -- We need some comments in this body ??? |
| |
| if Has_Stream_Attribute_Definition (Typ, Nam) then |
| return True; |
| end if; |
| |
| if Is_Class_Wide_Type (Typ) then |
| return not Is_Limited_Type (Typ) |
| or else Stream_Attribute_Available (Etype (Typ), Nam); |
| end if; |
| |
| if Nam = TSS_Stream_Input |
| and then Is_Abstract_Type (Typ) |
| and then not Is_Class_Wide_Type (Typ) |
| then |
| return False; |
| end if; |
| |
| if not (Is_Limited_Type (Typ) |
| or else (Present (Partial_View) |
| and then Is_Limited_Type (Partial_View))) |
| then |
| return True; |
| end if; |
| |
| -- In Ada 2005, Input can invoke Read, and Output can invoke Write |
| |
| if Nam = TSS_Stream_Input |
| and then Ada_Version >= Ada_2005 |
| and then Stream_Attribute_Available (Etyp, TSS_Stream_Read) |
| then |
| return True; |
| |
| elsif Nam = TSS_Stream_Output |
| and then Ada_Version >= Ada_2005 |
| and then Stream_Attribute_Available (Etyp, TSS_Stream_Write) |
| then |
| return True; |
| end if; |
| |
| -- Case of Read and Write: check for attribute definition clause that |
| -- applies to an ancestor type. |
| |
| while Etype (Etyp) /= Etyp loop |
| Etyp := Etype (Etyp); |
| |
| if Has_Stream_Attribute_Definition (Etyp, Nam) then |
| return True; |
| end if; |
| end loop; |
| |
| if Ada_Version < Ada_2005 then |
| |
| -- In Ada 95 mode, also consider a non-visible definition |
| |
| declare |
| Btyp : constant Entity_Id := Implementation_Base_Type (Typ); |
| begin |
| return Btyp /= Typ |
| and then Stream_Attribute_Available |
| (Btyp, Nam, Partial_View => Typ); |
| end; |
| end if; |
| |
| return False; |
| end Stream_Attribute_Available; |
| |
| end Sem_Attr; |