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gnu / gcc / 19220ca6aa79921cc431e41f25986e16410c7a6a / . / gcc / ada / sem_aggr.adb
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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ A G G R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2003 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Itypes; use Itypes;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Nmake; use Nmake;
with Nlists; use Nlists;
with Opt; use Opt;
with Sem; use Sem;
with Sem_Cat; use Sem_Cat;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch13; use Sem_Ch13;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sem_Type; use Sem_Type;
with Sem_Warn; use Sem_Warn;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stringt; use Stringt;
with Stand; use Stand;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
package body Sem_Aggr is
type Case_Bounds is record
Choice_Lo : Node_Id;
Choice_Hi : Node_Id;
Choice_Node : Node_Id;
end record;
type Case_Table_Type is array (Nat range <>) of Case_Bounds;
-- Table type used by Check_Case_Choices procedure
-----------------------
-- Local Subprograms --
-----------------------
procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
-- Sort the Case Table using the Lower Bound of each Choice as the key.
-- A simple insertion sort is used since the number of choices in a case
-- statement of variant part will usually be small and probably in near
-- sorted order.
------------------------------------------------------
-- Subprograms used for RECORD AGGREGATE Processing --
------------------------------------------------------
procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
-- This procedure performs all the semantic checks required for record
-- aggregates. Note that for aggregates analysis and resolution go
-- hand in hand. Aggregate analysis has been delayed up to here and
-- it is done while resolving the aggregate.
--
-- N is the N_Aggregate node.
-- Typ is the record type for the aggregate resolution
--
-- While performing the semantic checks, this procedure
-- builds a new Component_Association_List where each record field
-- appears alone in a Component_Choice_List along with its corresponding
-- expression. The record fields in the Component_Association_List
-- appear in the same order in which they appear in the record type Typ.
--
-- Once this new Component_Association_List is built and all the
-- semantic checks performed, the original aggregate subtree is replaced
-- with the new named record aggregate just built. Note that the subtree
-- substitution is performed with Rewrite so as to be
-- able to retrieve the original aggregate.
--
-- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
-- yields the aggregate format expected by Gigi. Typically, this kind of
-- tree manipulations are done in the expander. However, because the
-- semantic checks that need to be performed on record aggregates really
-- go hand in hand with the record aggregate normalization, the aggregate
-- subtree transformation is performed during resolution rather than
-- expansion. Had we decided otherwise we would have had to duplicate
-- most of the code in the expansion procedure Expand_Record_Aggregate.
-- Note, however, that all the expansion concerning aggegates for tagged
-- records is done in Expand_Record_Aggregate.
--
-- The algorithm of Resolve_Record_Aggregate proceeds as follows:
--
-- 1. Make sure that the record type against which the record aggregate
-- has to be resolved is not abstract. Furthermore if the type is
-- a null aggregate make sure the input aggregate N is also null.
--
-- 2. Verify that the structure of the aggregate is that of a record
-- aggregate. Specifically, look for component associations and ensure
-- that each choice list only has identifiers or the N_Others_Choice
-- node. Also make sure that if present, the N_Others_Choice occurs
-- last and by itself.
--
-- 3. If Typ contains discriminants, the values for each discriminant
-- is looked for. If the record type Typ has variants, we check
-- that the expressions corresponding to each discriminant ruling
-- the (possibly nested) variant parts of Typ, are static. This
-- allows us to determine the variant parts to which the rest of
-- the aggregate must conform. The names of discriminants with their
-- values are saved in a new association list, New_Assoc_List which
-- is later augmented with the names and values of the remaining
-- components in the record type.
--
-- During this phase we also make sure that every discriminant is
-- assigned exactly one value. Note that when several values
-- for a given discriminant are found, semantic processing continues
-- looking for further errors. In this case it's the first
-- discriminant value found which we will be recorded.
--
-- IMPORTANT NOTE: For derived tagged types this procedure expects
-- First_Discriminant and Next_Discriminant to give the correct list
-- of discriminants, in the correct order.
--
-- 4. After all the discriminant values have been gathered, we can
-- set the Etype of the record aggregate. If Typ contains no
-- discriminants this is straightforward: the Etype of N is just
-- Typ, otherwise a new implicit constrained subtype of Typ is
-- built to be the Etype of N.
--
-- 5. Gather the remaining record components according to the discriminant
-- values. This involves recursively traversing the record type
-- structure to see what variants are selected by the given discriminant
-- values. This processing is a little more convoluted if Typ is a
-- derived tagged types since we need to retrieve the record structure
-- of all the ancestors of Typ.
--
-- 6. After gathering the record components we look for their values
-- in the record aggregate and emit appropriate error messages
-- should we not find such values or should they be duplicated.
--
-- 7. We then make sure no illegal component names appear in the
-- record aggegate and make sure that the type of the record
-- components appearing in a same choice list is the same.
-- Finally we ensure that the others choice, if present, is
-- used to provide the value of at least a record component.
--
-- 8. The original aggregate node is replaced with the new named
-- aggregate built in steps 3 through 6, as explained earlier.
--
-- Given the complexity of record aggregate resolution, the primary
-- goal of this routine is clarity and simplicity rather than execution
-- and storage efficiency. If there are only positional components in the
-- aggregate the running time is linear. If there are associations
-- the running time is still linear as long as the order of the
-- associations is not too far off the order of the components in the
-- record type. If this is not the case the running time is at worst
-- quadratic in the size of the association list.
procedure Check_Misspelled_Component
(Elements : Elist_Id;
Component : Node_Id);
-- Give possible misspelling diagnostic if Component is likely to be
-- a misspelling of one of the components of the Assoc_List.
-- This is called by Resolv_Aggr_Expr after producing
-- an invalid component error message.
procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
-- An optimization: determine whether a discriminated subtype has a
-- static constraint, and contains array components whose length is also
-- static, either because they are constrained by the discriminant, or
-- because the original component bounds are static.
-----------------------------------------------------
-- Subprograms used for ARRAY AGGREGATE Processing --
-----------------------------------------------------
function Resolve_Array_Aggregate
(N : Node_Id;
Index : Node_Id;
Index_Constr : Node_Id;
Component_Typ : Entity_Id;
Others_Allowed : Boolean)
return Boolean;
-- This procedure performs the semantic checks for an array aggregate.
-- True is returned if the aggregate resolution succeeds.
-- The procedure works by recursively checking each nested aggregate.
-- Specifically, after checking a sub-aggreate nested at the i-th level
-- we recursively check all the subaggregates at the i+1-st level (if any).
-- Note that for aggregates analysis and resolution go hand in hand.
-- Aggregate analysis has been delayed up to here and it is done while
-- resolving the aggregate.
--
-- N is the current N_Aggregate node to be checked.
--
-- Index is the index node corresponding to the array sub-aggregate that
-- we are currently checking (RM 4.3.3 (8)). Its Etype is the
-- corresponding index type (or subtype).
--
-- Index_Constr is the node giving the applicable index constraint if
-- any (RM 4.3.3 (10)). It "is a constraint provided by certain
-- contexts [...] that can be used to determine the bounds of the array
-- value specified by the aggregate". If Others_Allowed below is False
-- there is no applicable index constraint and this node is set to Index.
--
-- Component_Typ is the array component type.
--
-- Others_Allowed indicates whether an others choice is allowed
-- in the context where the top-level aggregate appeared.
--
-- The algorithm of Resolve_Array_Aggregate proceeds as follows:
--
-- 1. Make sure that the others choice, if present, is by itself and
-- appears last in the sub-aggregate. Check that we do not have
-- positional and named components in the array sub-aggregate (unless
-- the named association is an others choice). Finally if an others
-- choice is present, make sure it is allowed in the aggregate contex.
--
-- 2. If the array sub-aggregate contains discrete_choices:
--
-- (A) Verify their validity. Specifically verify that:
--
-- (a) If a null range is present it must be the only possible
-- choice in the array aggregate.
--
-- (b) Ditto for a non static range.
--
-- (c) Ditto for a non static expression.
--
-- In addition this step analyzes and resolves each discrete_choice,
-- making sure that its type is the type of the corresponding Index.
-- If we are not at the lowest array aggregate level (in the case of
-- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
-- recursively on each component expression. Otherwise, resolve the
-- bottom level component expressions against the expected component
-- type ONLY IF the component corresponds to a single discrete choice
-- which is not an others choice (to see why read the DELAYED
-- COMPONENT RESOLUTION below).
--
-- (B) Determine the bounds of the sub-aggregate and lowest and
-- highest choice values.
--
-- 3. For positional aggregates:
--
-- (A) Loop over the component expressions either recursively invoking
-- Resolve_Array_Aggregate on each of these for multi-dimensional
-- array aggregates or resolving the bottom level component
-- expressions against the expected component type.
--
-- (B) Determine the bounds of the positional sub-aggregates.
--
-- 4. Try to determine statically whether the evaluation of the array
-- sub-aggregate raises Constraint_Error. If yes emit proper
-- warnings. The precise checks are the following:
--
-- (A) Check that the index range defined by aggregate bounds is
-- compatible with corresponding index subtype.
-- We also check against the base type. In fact it could be that
-- Low/High bounds of the base type are static whereas those of
-- the index subtype are not. Thus if we can statically catch
-- a problem with respect to the base type we are guaranteed
-- that the same problem will arise with the index subtype
--
-- (B) If we are dealing with a named aggregate containing an others
-- choice and at least one discrete choice then make sure the range
-- specified by the discrete choices does not overflow the
-- aggregate bounds. We also check against the index type and base
-- type bounds for the same reasons given in (A).
--
-- (C) If we are dealing with a positional aggregate with an others
-- choice make sure the number of positional elements specified
-- does not overflow the aggregate bounds. We also check against
-- the index type and base type bounds as mentioned in (A).
--
-- Finally construct an N_Range node giving the sub-aggregate bounds.
-- Set the Aggregate_Bounds field of the sub-aggregate to be this
-- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
-- to build the appropriate aggregate subtype. Aggregate_Bounds
-- information is needed during expansion.
--
-- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
-- expressions in an array aggregate may call Duplicate_Subexpr or some
-- other routine that inserts code just outside the outermost aggregate.
-- If the array aggregate contains discrete choices or an others choice,
-- this may be wrong. Consider for instance the following example.
--
-- type Rec is record
-- V : Integer := 0;
-- end record;
--
-- type Acc_Rec is access Rec;
-- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
--
-- Then the transformation of "new Rec" that occurs during resolution
-- entails the following code modifications
--
-- P7b : constant Acc_Rec := new Rec;
-- RecIP (P7b.all);
-- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
--
-- This code transformation is clearly wrong, since we need to call
-- "new Rec" for each of the 3 array elements. To avoid this problem we
-- delay resolution of the components of non positional array aggregates
-- to the expansion phase. As an optimization, if the discrete choice
-- specifies a single value we do not delay resolution.
function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
-- This routine returns the type or subtype of an array aggregate.
--
-- N is the array aggregate node whose type we return.
--
-- Typ is the context type in which N occurs.
--
-- This routine creates an implicit array subtype whose bounds are
-- those defined by the aggregate. When this routine is invoked
-- Resolve_Array_Aggregate has already processed aggregate N. Thus the
-- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
-- sub-aggregate bounds. When building the aggegate itype, this function
-- traverses the array aggregate N collecting such Aggregate_Bounds and
-- constructs the proper array aggregate itype.
--
-- Note that in the case of multidimensional aggregates each inner
-- sub-aggregate corresponding to a given array dimension, may provide a
-- different bounds. If it is possible to determine statically that
-- some sub-aggregates corresponding to the same index do not have the
-- same bounds, then a warning is emitted. If such check is not possible
-- statically (because some sub-aggregate bounds are dynamic expressions)
-- then this job is left to the expander. In all cases the particular
-- bounds that this function will chose for a given dimension is the first
-- N_Range node for a sub-aggregate corresponding to that dimension.
--
-- Note that the Raises_Constraint_Error flag of an array aggregate
-- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
-- is set in Resolve_Array_Aggregate but the aggregate is not
-- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
-- first construct the proper itype for the aggregate (Gigi needs
-- this). After constructing the proper itype we will eventually replace
-- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
-- Of course in cases such as:
--
-- type Arr is array (integer range <>) of Integer;
-- A : Arr := (positive range -1 .. 2 => 0);
--
-- The bounds of the aggregate itype are cooked up to look reasonable
-- (in this particular case the bounds will be 1 .. 2).
procedure Aggregate_Constraint_Checks
(Exp : Node_Id;
Check_Typ : Entity_Id);
-- Checks expression Exp against subtype Check_Typ. If Exp is an
-- aggregate and Check_Typ a constrained record type with discriminants,
-- we generate the appropriate discriminant checks. If Exp is an array
-- aggregate then emit the appropriate length checks. If Exp is a scalar
-- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
-- ensure that range checks are performed at run time.
procedure Make_String_Into_Aggregate (N : Node_Id);
-- A string literal can appear in a context in which a one dimensional
-- array of characters is expected. This procedure simply rewrites the
-- string as an aggregate, prior to resolution.
---------------------------------
-- Aggregate_Constraint_Checks --
---------------------------------
procedure Aggregate_Constraint_Checks
(Exp : Node_Id;
Check_Typ : Entity_Id)
is
Exp_Typ : constant Entity_Id := Etype (Exp);
begin
if Raises_Constraint_Error (Exp) then
return;
end if;
-- This is really expansion activity, so make sure that expansion
-- is on and is allowed.
if not Expander_Active or else In_Default_Expression then
return;
end if;
-- First check if we have to insert discriminant checks
if Has_Discriminants (Exp_Typ) then
Apply_Discriminant_Check (Exp, Check_Typ);
-- Next emit length checks for array aggregates
elsif Is_Array_Type (Exp_Typ) then
Apply_Length_Check (Exp, Check_Typ);
-- Finally emit scalar and string checks. If we are dealing with a
-- scalar literal we need to check by hand because the Etype of
-- literals is not necessarily correct.
elsif Is_Scalar_Type (Exp_Typ)
and then Compile_Time_Known_Value (Exp)
then
if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then
Apply_Compile_Time_Constraint_Error
(Exp, "value not in range of}?", CE_Range_Check_Failed,
Ent => Base_Type (Check_Typ),
Typ => Base_Type (Check_Typ));
elsif Is_Out_Of_Range (Exp, Check_Typ) then
Apply_Compile_Time_Constraint_Error
(Exp, "value not in range of}?", CE_Range_Check_Failed,
Ent => Check_Typ,
Typ => Check_Typ);
elsif not Range_Checks_Suppressed (Check_Typ) then
Apply_Scalar_Range_Check (Exp, Check_Typ);
end if;
elsif (Is_Scalar_Type (Exp_Typ)
or else Nkind (Exp) = N_String_Literal)
and then Exp_Typ /= Check_Typ
then
if Is_Entity_Name (Exp)
and then Ekind (Entity (Exp)) = E_Constant
then
-- If expression is a constant, it is worthwhile checking whether
-- it is a bound of the type.
if (Is_Entity_Name (Type_Low_Bound (Check_Typ))
and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ)))
or else (Is_Entity_Name (Type_High_Bound (Check_Typ))
and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ)))
then
return;
else
Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
Analyze_And_Resolve (Exp, Check_Typ);
Check_Unset_Reference (Exp);
end if;
else
Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
Analyze_And_Resolve (Exp, Check_Typ);
Check_Unset_Reference (Exp);
end if;
end if;
end Aggregate_Constraint_Checks;
------------------------
-- Array_Aggr_Subtype --
------------------------
function Array_Aggr_Subtype
(N : Node_Id;
Typ : Entity_Id)
return Entity_Id
is
Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
-- Number of aggregate index dimensions.
Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
-- Constrained N_Range of each index dimension in our aggregate itype.
Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
-- Low and High bounds for each index dimension in our aggregate itype.
Is_Fully_Positional : Boolean := True;
procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
-- N is an array (sub-)aggregate. Dim is the dimension corresponding to
-- (sub-)aggregate N. This procedure collects the constrained N_Range
-- nodes corresponding to each index dimension of our aggregate itype.
-- These N_Range nodes are collected in Aggr_Range above.
-- Likewise collect in Aggr_Low & Aggr_High above the low and high
-- bounds of each index dimension. If, when collecting, two bounds
-- corresponding to the same dimension are static and found to differ,
-- then emit a warning, and mark N as raising Constraint_Error.
-------------------------
-- Collect_Aggr_Bounds --
-------------------------
procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
This_Range : constant Node_Id := Aggregate_Bounds (N);
-- The aggregate range node of this specific sub-aggregate.
This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
-- The aggregate bounds of this specific sub-aggregate.
Assoc : Node_Id;
Expr : Node_Id;
begin
-- Collect the first N_Range for a given dimension that you find.
-- For a given dimension they must be all equal anyway.
if No (Aggr_Range (Dim)) then
Aggr_Low (Dim) := This_Low;
Aggr_High (Dim) := This_High;
Aggr_Range (Dim) := This_Range;
else
if Compile_Time_Known_Value (This_Low) then
if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
Aggr_Low (Dim) := This_Low;
elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
Set_Raises_Constraint_Error (N);
Error_Msg_N ("Sub-aggregate low bound mismatch?", N);
Error_Msg_N ("Constraint_Error will be raised at run-time?",
N);
end if;
end if;
if Compile_Time_Known_Value (This_High) then
if not Compile_Time_Known_Value (Aggr_High (Dim)) then
Aggr_High (Dim) := This_High;
elsif
Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
then
Set_Raises_Constraint_Error (N);
Error_Msg_N ("Sub-aggregate high bound mismatch?", N);
Error_Msg_N ("Constraint_Error will be raised at run-time?",
N);
end if;
end if;
end if;
if Dim < Aggr_Dimension then
-- Process positional components
if Present (Expressions (N)) then
Expr := First (Expressions (N));
while Present (Expr) loop
Collect_Aggr_Bounds (Expr, Dim + 1);
Next (Expr);
end loop;
end if;
-- Process component associations
if Present (Component_Associations (N)) then
Is_Fully_Positional := False;
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
Expr := Expression (Assoc);
Collect_Aggr_Bounds (Expr, Dim + 1);
Next (Assoc);
end loop;
end if;
end if;
end Collect_Aggr_Bounds;
-- Array_Aggr_Subtype variables
Itype : Entity_Id;
-- the final itype of the overall aggregate
Index_Constraints : constant List_Id := New_List;
-- The list of index constraints of the aggregate itype.
-- Start of processing for Array_Aggr_Subtype
begin
-- Make sure that the list of index constraints is properly attached
-- to the tree, and then collect the aggregate bounds.
Set_Parent (Index_Constraints, N);
Collect_Aggr_Bounds (N, 1);
-- Build the list of constrained indices of our aggregate itype.
for J in 1 .. Aggr_Dimension loop
Create_Index : declare
Index_Base : constant Entity_Id :=
Base_Type (Etype (Aggr_Range (J)));
Index_Typ : Entity_Id;
begin
-- Construct the Index subtype
Index_Typ := Create_Itype (Subtype_Kind (Ekind (Index_Base)), N);
Set_Etype (Index_Typ, Index_Base);
if Is_Character_Type (Index_Base) then
Set_Is_Character_Type (Index_Typ);
end if;
Set_Size_Info (Index_Typ, (Index_Base));
Set_RM_Size (Index_Typ, RM_Size (Index_Base));
Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
Set_Scalar_Range (Index_Typ, Aggr_Range (J));
if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
end if;
Set_Etype (Aggr_Range (J), Index_Typ);
Append (Aggr_Range (J), To => Index_Constraints);
end Create_Index;
end loop;
-- Now build the Itype
Itype := Create_Itype (E_Array_Subtype, N);
Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
Set_Convention (Itype, Convention (Typ));
Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
Set_Etype (Itype, Base_Type (Typ));
Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
Set_Is_Aliased (Itype, Is_Aliased (Typ));
Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
Copy_Suppress_Status (Index_Check, Typ, Itype);
Copy_Suppress_Status (Length_Check, Typ, Itype);
Set_First_Index (Itype, First (Index_Constraints));
Set_Is_Constrained (Itype, True);
Set_Is_Internal (Itype, True);
Init_Size_Align (Itype);
-- A simple optimization: purely positional aggregates of static
-- components should be passed to gigi unexpanded whenever possible,
-- and regardless of the staticness of the bounds themselves. Subse-
-- quent checks in exp_aggr verify that type is not packed, etc.
Set_Size_Known_At_Compile_Time (Itype,
Is_Fully_Positional
and then Comes_From_Source (N)
and then Size_Known_At_Compile_Time (Component_Type (Typ)));
-- We always need a freeze node for a packed array subtype, so that
-- we can build the Packed_Array_Type corresponding to the subtype.
-- If expansion is disabled, the packed array subtype is not built,
-- and we must not generate a freeze node for the type, or else it
-- will appear incomplete to gigi.
if Is_Packed (Itype) and then not In_Default_Expression
and then Expander_Active
then
Freeze_Itype (Itype, N);
end if;
return Itype;
end Array_Aggr_Subtype;
--------------------------------
-- Check_Misspelled_Component --
--------------------------------
procedure Check_Misspelled_Component
(Elements : Elist_Id;
Component : Node_Id)
is
Max_Suggestions : constant := 2;
Nr_Of_Suggestions : Natural := 0;
Suggestion_1 : Entity_Id := Empty;
Suggestion_2 : Entity_Id := Empty;
Component_Elmt : Elmt_Id;
begin
-- All the components of List are matched against Component and
-- a count is maintained of possible misspellings. When at the
-- end of the analysis there are one or two (not more!) possible
-- misspellings, these misspellings will be suggested as
-- possible correction.
Get_Name_String (Chars (Component));
declare
S : constant String (1 .. Name_Len) :=
Name_Buffer (1 .. Name_Len);
begin
Component_Elmt := First_Elmt (Elements);
while Nr_Of_Suggestions <= Max_Suggestions
and then Present (Component_Elmt)
loop
Get_Name_String (Chars (Node (Component_Elmt)));
if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then
Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
case Nr_Of_Suggestions is
when 1 => Suggestion_1 := Node (Component_Elmt);
when 2 => Suggestion_2 := Node (Component_Elmt);
when others => exit;
end case;
end if;
Next_Elmt (Component_Elmt);
end loop;
-- Report at most two suggestions
if Nr_Of_Suggestions = 1 then
Error_Msg_NE ("\possible misspelling of&",
Component, Suggestion_1);
elsif Nr_Of_Suggestions = 2 then
Error_Msg_Node_2 := Suggestion_2;
Error_Msg_NE ("\possible misspelling of& or&",
Component, Suggestion_1);
end if;
end;
end Check_Misspelled_Component;
----------------------------------------
-- Check_Static_Discriminated_Subtype --
----------------------------------------
procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
Disc : constant Entity_Id := First_Discriminant (T);
Comp : Entity_Id;
Ind : Entity_Id;
begin
if Has_Record_Rep_Clause (T) then
return;
elsif Present (Next_Discriminant (Disc)) then
return;
elsif Nkind (V) /= N_Integer_Literal then
return;
end if;
Comp := First_Component (T);
while Present (Comp) loop
if Is_Scalar_Type (Etype (Comp)) then
null;
elsif Is_Private_Type (Etype (Comp))
and then Present (Full_View (Etype (Comp)))
and then Is_Scalar_Type (Full_View (Etype (Comp)))
then
null;
elsif Is_Array_Type (Etype (Comp)) then
if Is_Bit_Packed_Array (Etype (Comp)) then
return;
end if;
Ind := First_Index (Etype (Comp));
while Present (Ind) loop
if Nkind (Ind) /= N_Range
or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
then
return;
end if;
Next_Index (Ind);
end loop;
else
return;
end if;
Next_Component (Comp);
end loop;
-- On exit, all components have statically known sizes.
Set_Size_Known_At_Compile_Time (T);
end Check_Static_Discriminated_Subtype;
--------------------------------
-- Make_String_Into_Aggregate --
--------------------------------
procedure Make_String_Into_Aggregate (N : Node_Id) is
Exprs : constant List_Id := New_List;
Loc : constant Source_Ptr := Sloc (N);
Str : constant String_Id := Strval (N);
Strlen : constant Nat := String_Length (Str);
C : Char_Code;
C_Node : Node_Id;
New_N : Node_Id;
P : Source_Ptr;
begin
P := Loc + 1;
for J in 1 .. Strlen loop
C := Get_String_Char (Str, J);
Set_Character_Literal_Name (C);
C_Node := Make_Character_Literal (P, Name_Find, C);
Set_Etype (C_Node, Any_Character);
Append_To (Exprs, C_Node);
P := P + 1;
-- something special for wide strings ???
end loop;
New_N := Make_Aggregate (Loc, Expressions => Exprs);
Set_Analyzed (New_N);
Set_Etype (New_N, Any_Composite);
Rewrite (N, New_N);
end Make_String_Into_Aggregate;
-----------------------
-- Resolve_Aggregate --
-----------------------
procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
Pkind : constant Node_Kind := Nkind (Parent (N));
Aggr_Subtyp : Entity_Id;
-- The actual aggregate subtype. This is not necessarily the same as Typ
-- which is the subtype of the context in which the aggregate was found.
begin
-- Check for aggregates not allowed in configurable run-time mode.
-- We allow all cases of aggregates that do not come from source,
-- since these are all assumed to be small (e.g. bounds of a string
-- literal). We also allow aggregates of types we know to be small.
if not Support_Aggregates_On_Target
and then Comes_From_Source (N)
and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
then
Error_Msg_CRT ("aggregate", N);
end if;
if Is_Limited_Composite (Typ) then
Error_Msg_N ("aggregate type cannot have limited component", N);
Explain_Limited_Type (Typ, N);
-- Ada0Y (AI-287): Limited aggregates allowed
elsif Is_Limited_Type (Typ)
and not Extensions_Allowed
then
Error_Msg_N ("aggregate type cannot be limited", N);
Explain_Limited_Type (Typ, N);
elsif Is_Class_Wide_Type (Typ) then
Error_Msg_N ("type of aggregate cannot be class-wide", N);
elsif Typ = Any_String
or else Typ = Any_Composite
then
Error_Msg_N ("no unique type for aggregate", N);
Set_Etype (N, Any_Composite);
elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
Error_Msg_N ("null record forbidden in array aggregate", N);
elsif Is_Record_Type (Typ) then
Resolve_Record_Aggregate (N, Typ);
elsif Is_Array_Type (Typ) then
-- First a special test, for the case of a positional aggregate
-- of characters which can be replaced by a string literal.
-- Do not perform this transformation if this was a string literal
-- to start with, whose components needed constraint checks, or if
-- the component type is non-static, because it will require those
-- checks and be transformed back into an aggregate.
if Number_Dimensions (Typ) = 1
and then
(Root_Type (Component_Type (Typ)) = Standard_Character
or else
Root_Type (Component_Type (Typ)) = Standard_Wide_Character)
and then No (Component_Associations (N))
and then not Is_Limited_Composite (Typ)
and then not Is_Private_Composite (Typ)
and then not Is_Bit_Packed_Array (Typ)
and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
and then Is_Static_Subtype (Component_Type (Typ))
then
declare
Expr : Node_Id;
begin
Expr := First (Expressions (N));
while Present (Expr) loop
exit when Nkind (Expr) /= N_Character_Literal;
Next (Expr);
end loop;
if No (Expr) then
Start_String;
Expr := First (Expressions (N));
while Present (Expr) loop
Store_String_Char (Char_Literal_Value (Expr));
Next (Expr);
end loop;
Rewrite (N,
Make_String_Literal (Sloc (N), End_String));
Analyze_And_Resolve (N, Typ);
return;
end if;
end;
end if;
-- Here if we have a real aggregate to deal with
Array_Aggregate : declare
Aggr_Resolved : Boolean;
Aggr_Typ : constant Entity_Id := Etype (Typ);
-- This is the unconstrained array type, which is the type
-- against which the aggregate is to be resoved. Typ itself
-- is the array type of the context which may not be the same
-- subtype as the subtype for the final aggregate.
begin
-- In the following we determine whether an others choice is
-- allowed inside the array aggregate. The test checks the context
-- in which the array aggregate occurs. If the context does not
-- permit it, or the aggregate type is unconstrained, an others
-- choice is not allowed.
--
-- Note that there is no node for Explicit_Actual_Parameter.
-- To test for this context we therefore have to test for node
-- N_Parameter_Association which itself appears only if there is a
-- formal parameter. Consequently we also need to test for
-- N_Procedure_Call_Statement or N_Function_Call.
Set_Etype (N, Aggr_Typ); -- may be overridden later on.
if Is_Constrained (Typ) and then
(Pkind = N_Assignment_Statement or else
Pkind = N_Parameter_Association or else
Pkind = N_Function_Call or else
Pkind = N_Procedure_Call_Statement or else
Pkind = N_Generic_Association or else
Pkind = N_Formal_Object_Declaration or else
Pkind = N_Return_Statement or else
Pkind = N_Object_Declaration or else
Pkind = N_Component_Declaration or else
Pkind = N_Parameter_Specification or else
Pkind = N_Qualified_Expression or else
Pkind = N_Aggregate or else
Pkind = N_Extension_Aggregate or else
Pkind = N_Component_Association)
then
Aggr_Resolved :=
Resolve_Array_Aggregate
(N,
Index => First_Index (Aggr_Typ),
Index_Constr => First_Index (Typ),
Component_Typ => Component_Type (Typ),
Others_Allowed => True);
else
Aggr_Resolved :=
Resolve_Array_Aggregate
(N,
Index => First_Index (Aggr_Typ),
Index_Constr => First_Index (Aggr_Typ),
Component_Typ => Component_Type (Typ),
Others_Allowed => False);
end if;
if not Aggr_Resolved then
Aggr_Subtyp := Any_Composite;
else
Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
end if;
Set_Etype (N, Aggr_Subtyp);
end Array_Aggregate;
else
Error_Msg_N ("illegal context for aggregate", N);
end if;
-- If we can determine statically that the evaluation of the
-- aggregate raises Constraint_Error, then replace the
-- aggregate with an N_Raise_Constraint_Error node, but set the
-- Etype to the right aggregate subtype. Gigi needs this.
if Raises_Constraint_Error (N) then
Aggr_Subtyp := Etype (N);
Rewrite (N,
Make_Raise_Constraint_Error (Sloc (N),
Reason => CE_Range_Check_Failed));
Set_Raises_Constraint_Error (N);
Set_Etype (N, Aggr_Subtyp);
Set_Analyzed (N);
end if;
end Resolve_Aggregate;
-----------------------------
-- Resolve_Array_Aggregate --
-----------------------------
function Resolve_Array_Aggregate
(N : Node_Id;
Index : Node_Id;
Index_Constr : Node_Id;
Component_Typ : Entity_Id;
Others_Allowed : Boolean)
return Boolean
is
Loc : constant Source_Ptr := Sloc (N);
Failure : constant Boolean := False;
Success : constant Boolean := True;
Index_Typ : constant Entity_Id := Etype (Index);
Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
-- The type of the index corresponding to the array sub-aggregate
-- along with its low and upper bounds
Index_Base : constant Entity_Id := Base_Type (Index_Typ);
Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
-- ditto for the base type
function Add (Val : Uint; To : Node_Id) return Node_Id;
-- Creates a new expression node where Val is added to expression To.
-- Tries to constant fold whenever possible. To must be an already
-- analyzed expression.
procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
-- Checks that AH (the upper bound of an array aggregate) is <= BH
-- (the upper bound of the index base type). If the check fails a
-- warning is emitted, the Raises_Constraint_Error Flag of N is set,
-- and AH is replaced with a duplicate of BH.
procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
-- Checks that range AL .. AH is compatible with range L .. H. Emits a
-- warning if not and sets the Raises_Constraint_Error Flag in N.
procedure Check_Length (L, H : Node_Id; Len : Uint);
-- Checks that range L .. H contains at least Len elements. Emits a
-- warning if not and sets the Raises_Constraint_Error Flag in N.
function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
-- Returns True if range L .. H is dynamic or null.
procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
-- Given expression node From, this routine sets OK to False if it
-- cannot statically evaluate From. Otherwise it stores this static
-- value into Value.
function Resolve_Aggr_Expr
(Expr : Node_Id;
Single_Elmt : Boolean)
return Boolean;
-- Resolves aggregate expression Expr. Returs False if resolution
-- fails. If Single_Elmt is set to False, the expression Expr may be
-- used to initialize several array aggregate elements (this can
-- happen for discrete choices such as "L .. H => Expr" or the others
-- choice). In this event we do not resolve Expr unless expansion is
-- disabled. To know why, see the DELAYED COMPONENT RESOLUTION
-- note above.
---------
-- Add --
---------
function Add (Val : Uint; To : Node_Id) return Node_Id is
Expr_Pos : Node_Id;
Expr : Node_Id;
To_Pos : Node_Id;
begin
if Raises_Constraint_Error (To) then
return To;
end if;
-- First test if we can do constant folding
if Compile_Time_Known_Value (To)
or else Nkind (To) = N_Integer_Literal
then
Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
Set_Is_Static_Expression (Expr_Pos);
Set_Etype (Expr_Pos, Etype (To));
Set_Analyzed (Expr_Pos, Analyzed (To));
if not Is_Enumeration_Type (Index_Typ) then
Expr := Expr_Pos;
-- If we are dealing with enumeration return
-- Index_Typ'Val (Expr_Pos)
else
Expr :=
Make_Attribute_Reference
(Loc,
Prefix => New_Reference_To (Index_Typ, Loc),
Attribute_Name => Name_Val,
Expressions => New_List (Expr_Pos));
end if;
return Expr;
end if;
-- If we are here no constant folding possible
if not Is_Enumeration_Type (Index_Base) then
Expr :=
Make_Op_Add (Loc,
Left_Opnd => Duplicate_Subexpr (To),
Right_Opnd => Make_Integer_Literal (Loc, Val));
-- If we are dealing with enumeration return
-- Index_Typ'Val (Index_Typ'Pos (To) + Val)
else
To_Pos :=
Make_Attribute_Reference
(Loc,
Prefix => New_Reference_To (Index_Typ, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (Duplicate_Subexpr (To)));
Expr_Pos :=
Make_Op_Add (Loc,
Left_Opnd => To_Pos,
Right_Opnd => Make_Integer_Literal (Loc, Val));
Expr :=
Make_Attribute_Reference
(Loc,
Prefix => New_Reference_To (Index_Typ, Loc),
Attribute_Name => Name_Val,
Expressions => New_List (Expr_Pos));
end if;
return Expr;
end Add;
-----------------
-- Check_Bound --
-----------------
procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
Val_BH : Uint;
Val_AH : Uint;
OK_BH : Boolean;
OK_AH : Boolean;
begin
Get (Value => Val_BH, From => BH, OK => OK_BH);
Get (Value => Val_AH, From => AH, OK => OK_AH);
if OK_BH and then OK_AH and then Val_BH < Val_AH then
Set_Raises_Constraint_Error (N);
Error_Msg_N ("upper bound out of range?", AH);
Error_Msg_N ("Constraint_Error will be raised at run-time?", AH);
-- You need to set AH to BH or else in the case of enumerations
-- indices we will not be able to resolve the aggregate bounds.
AH := Duplicate_Subexpr (BH);
end if;
end Check_Bound;
------------------
-- Check_Bounds --
------------------
procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
Val_L : Uint;
Val_H : Uint;
Val_AL : Uint;
Val_AH : Uint;
OK_L : Boolean;
OK_H : Boolean;
OK_AL : Boolean;
OK_AH : Boolean;
begin
if Raises_Constraint_Error (N)
or else Dynamic_Or_Null_Range (AL, AH)
then
return;
end if;
Get (Value => Val_L, From => L, OK => OK_L);
Get (Value => Val_H, From => H, OK => OK_H);
Get (Value => Val_AL, From => AL, OK => OK_AL);
Get (Value => Val_AH, From => AH, OK => OK_AH);
if OK_L and then Val_L > Val_AL then
Set_Raises_Constraint_Error (N);
Error_Msg_N ("lower bound of aggregate out of range?", N);
Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
end if;
if OK_H and then Val_H < Val_AH then
Set_Raises_Constraint_Error (N);
Error_Msg_N ("upper bound of aggregate out of range?", N);
Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
end if;
end Check_Bounds;
------------------
-- Check_Length --
------------------
procedure Check_Length (L, H : Node_Id; Len : Uint) is
Val_L : Uint;
Val_H : Uint;
OK_L : Boolean;
OK_H : Boolean;
Range_Len : Uint;
begin
if Raises_Constraint_Error (N) then
return;
end if;
Get (Value => Val_L, From => L, OK => OK_L);
Get (Value => Val_H, From => H, OK => OK_H);
if not OK_L or else not OK_H then
return;
end if;
-- If null range length is zero
if Val_L > Val_H then
Range_Len := Uint_0;
else
Range_Len := Val_H - Val_L + 1;
end if;
if Range_Len < Len then
Set_Raises_Constraint_Error (N);
Error_Msg_N ("Too many elements?", N);
Error_Msg_N ("Constraint_Error will be raised at run-time?", N);
end if;
end Check_Length;
---------------------------
-- Dynamic_Or_Null_Range --
---------------------------
function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
Val_L : Uint;
Val_H : Uint;
OK_L : Boolean;
OK_H : Boolean;
begin
Get (Value => Val_L, From => L, OK => OK_L);
Get (Value => Val_H, From => H, OK => OK_H);
return not OK_L or else not OK_H
or else not Is_OK_Static_Expression (L)
or else not Is_OK_Static_Expression (H)
or else Val_L > Val_H;
end Dynamic_Or_Null_Range;
---------
-- Get --
---------
procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
begin
OK := True;
if Compile_Time_Known_Value (From) then
Value := Expr_Value (From);
-- If expression From is something like Some_Type'Val (10) then
-- Value = 10
elsif Nkind (From) = N_Attribute_Reference
and then Attribute_Name (From) = Name_Val
and then Compile_Time_Known_Value (First (Expressions (From)))
then
Value := Expr_Value (First (Expressions (From)));
else
Value := Uint_0;
OK := False;
end if;
end Get;
-----------------------
-- Resolve_Aggr_Expr --
-----------------------
function Resolve_Aggr_Expr
(Expr : Node_Id;
Single_Elmt : Boolean)
return Boolean
is
Nxt_Ind : constant Node_Id := Next_Index (Index);
Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
-- Index is the current index corresponding to the expresion.
Resolution_OK : Boolean := True;
-- Set to False if resolution of the expression failed.
begin
-- If the array type against which we are resolving the aggregate
-- has several dimensions, the expressions nested inside the
-- aggregate must be further aggregates (or strings).
if Present (Nxt_Ind) then
if Nkind (Expr) /= N_Aggregate then
-- A string literal can appear where a one-dimensional array
-- of characters is expected. If the literal looks like an
-- operator, it is still an operator symbol, which will be
-- transformed into a string when analyzed.
if Is_Character_Type (Component_Typ)
and then No (Next_Index (Nxt_Ind))
and then (Nkind (Expr) = N_String_Literal
or else Nkind (Expr) = N_Operator_Symbol)
then
-- A string literal used in a multidimensional array
-- aggregate in place of the final one-dimensional
-- aggregate must not be enclosed in parentheses.
if Paren_Count (Expr) /= 0 then
Error_Msg_N ("No parenthesis allowed here", Expr);
end if;
Make_String_Into_Aggregate (Expr);
else
Error_Msg_N ("nested array aggregate expected", Expr);
return Failure;
end if;
end if;
Resolution_OK := Resolve_Array_Aggregate
(Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
-- Do not resolve the expressions of discrete or others choices
-- unless the expression covers a single component, or the expander
-- is inactive.
elsif Single_Elmt
or else not Expander_Active
or else In_Default_Expression
then
Analyze_And_Resolve (Expr, Component_Typ);
Check_Non_Static_Context (Expr);
Aggregate_Constraint_Checks (Expr, Component_Typ);
Check_Unset_Reference (Expr);
end if;
if Raises_Constraint_Error (Expr)
and then Nkind (Parent (Expr)) /= N_Component_Association
then
Set_Raises_Constraint_Error (N);
end if;
return Resolution_OK;
end Resolve_Aggr_Expr;
-- Variables local to Resolve_Array_Aggregate
Assoc : Node_Id;
Choice : Node_Id;
Expr : Node_Id;
Who_Cares : Node_Id;
Aggr_Low : Node_Id := Empty;
Aggr_High : Node_Id := Empty;
-- The actual low and high bounds of this sub-aggegate
Choices_Low : Node_Id := Empty;
Choices_High : Node_Id := Empty;
-- The lowest and highest discrete choices values for a named aggregate
Nb_Elements : Uint := Uint_0;
-- The number of elements in a positional aggegate
Others_Present : Boolean := False;
Nb_Choices : Nat := 0;
-- Contains the overall number of named choices in this sub-aggregate
Nb_Discrete_Choices : Nat := 0;
-- The overall number of discrete choices (not counting others choice)
Case_Table_Size : Nat;
-- Contains the size of the case table needed to sort aggregate choices
-- Start of processing for Resolve_Array_Aggregate
begin
-- STEP 1: make sure the aggregate is correctly formatted
if Present (Component_Associations (N)) then
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
Choice := First (Choices (Assoc));
while Present (Choice) loop
if Nkind (Choice) = N_Others_Choice then
Others_Present := True;
if Choice /= First (Choices (Assoc))
or else Present (Next (Choice))
then
Error_Msg_N
("OTHERS must appear alone in a choice list", Choice);
return Failure;
end if;
if Present (Next (Assoc)) then
Error_Msg_N
("OTHERS must appear last in an aggregate", Choice);
return Failure;
end if;
if Ada_83
and then Assoc /= First (Component_Associations (N))
and then (Nkind (Parent (N)) = N_Assignment_Statement
or else
Nkind (Parent (N)) = N_Object_Declaration)
then
Error_Msg_N
("(Ada 83) illegal context for OTHERS choice", N);
end if;
end if;
Nb_Choices := Nb_Choices + 1;
Next (Choice);
end loop;
Next (Assoc);
end loop;
end if;
-- At this point we know that the others choice, if present, is by
-- itself and appears last in the aggregate. Check if we have mixed
-- positional and discrete associations (other than the others choice).
if Present (Expressions (N))
and then (Nb_Choices > 1
or else (Nb_Choices = 1 and then not Others_Present))
then
Error_Msg_N
("named association cannot follow positional association",
First (Choices (First (Component_Associations (N)))));
return Failure;
end if;
-- Test for the validity of an others choice if present
if Others_Present and then not Others_Allowed then
Error_Msg_N
("OTHERS choice not allowed here",
First (Choices (First (Component_Associations (N)))));
return Failure;
end if;
-- Protect against cascaded errors
if Etype (Index_Typ) = Any_Type then
return Failure;
end if;
-- STEP 2: Process named components
if No (Expressions (N)) then
if Others_Present then
Case_Table_Size := Nb_Choices - 1;
else
Case_Table_Size := Nb_Choices;
end if;
Step_2 : declare
Low : Node_Id;
High : Node_Id;
-- Denote the lowest and highest values in an aggregate choice
Hi_Val : Uint;
Lo_Val : Uint;
-- High end of one range and Low end of the next. Should be
-- contiguous if there is no hole in the list of values.
Missing_Values : Boolean;
-- Set True if missing index values
S_Low : Node_Id := Empty;
S_High : Node_Id := Empty;
-- if a choice in an aggregate is a subtype indication these
-- denote the lowest and highest values of the subtype
Table : Case_Table_Type (1 .. Case_Table_Size);
-- Used to sort all the different choice values
Single_Choice : Boolean;
-- Set to true every time there is a single discrete choice in a
-- discrete association
Prev_Nb_Discrete_Choices : Nat;
-- Used to keep track of the number of discrete choices
-- in the current association.
begin
-- STEP 2 (A): Check discrete choices validity.
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
Choice := First (Choices (Assoc));
loop
Analyze (Choice);
if Nkind (Choice) = N_Others_Choice then
Single_Choice := False;
exit;
-- Test for subtype mark without constraint
elsif Is_Entity_Name (Choice) and then
Is_Type (Entity (Choice))
then
if Base_Type (Entity (Choice)) /= Index_Base then
Error_Msg_N
("invalid subtype mark in aggregate choice",
Choice);
return Failure;
end if;
elsif Nkind (Choice) = N_Subtype_Indication then
Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
-- Does the subtype indication evaluation raise CE ?
Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
Get_Index_Bounds (Choice, Low, High);
Check_Bounds (S_Low, S_High, Low, High);
else -- Choice is a range or an expression
Resolve (Choice, Index_Base);
Check_Unset_Reference (Choice);
Check_Non_Static_Context (Choice);
-- Do not range check a choice. This check is redundant
-- since this test is already performed when we check
-- that the bounds of the array aggregate are within
-- range.
Set_Do_Range_Check (Choice, False);
end if;
-- If we could not resolve the discrete choice stop here
if Etype (Choice) = Any_Type then
return Failure;
-- If the discrete choice raises CE get its original bounds.
elsif Nkind (Choice) = N_Raise_Constraint_Error then
Set_Raises_Constraint_Error (N);
Get_Index_Bounds (Original_Node (Choice), Low, High);
-- Otherwise get its bounds as usual
else
Get_Index_Bounds (Choice, Low, High);
end if;
if (Dynamic_Or_Null_Range (Low, High)
or else (Nkind (Choice) = N_Subtype_Indication
and then
Dynamic_Or_Null_Range (S_Low, S_High)))
and then Nb_Choices /= 1
then
Error_Msg_N
("dynamic or empty choice in aggregate " &
"must be the only choice", Choice);
return Failure;
end if;
Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
Table (Nb_Discrete_Choices).Choice_Lo := Low;
Table (Nb_Discrete_Choices).Choice_Hi := High;
Next (Choice);
if No (Choice) then
-- Check if we have a single discrete choice and whether
-- this discrete choice specifies a single value.
Single_Choice :=
(Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
and then (Low = High);
exit;
end if;
end loop;
-- Ada0Y (AI-287): In case of default initialized component
-- we delay the resolution to the expansion phase
if Box_Present (Assoc) then
-- Ada0Y (AI-287): In case of default initialization of a
-- component the expander will generate calls to the
-- corresponding initialization subprogram.
if Present (Base_Init_Proc (Etype (Component_Typ)))
or else Has_Task (Base_Type (Component_Typ))
then
null;
else
Error_Msg_N
("(Ada 0Y): no value supplied for this component",
Assoc);
end if;
elsif not Resolve_Aggr_Expr (Expression (Assoc),
Single_Elmt => Single_Choice)
then
return Failure;
end if;
Next (Assoc);
end loop;
-- If aggregate contains more than one choice then these must be
-- static. Sort them and check that they are contiguous
if Nb_Discrete_Choices > 1 then
Sort_Case_Table (Table);
Missing_Values := False;
Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop
if Expr_Value (Table (J).Choice_Hi) >=
Expr_Value (Table (J + 1).Choice_Lo)
then
Error_Msg_N
("duplicate choice values in array aggregate",
Table (J).Choice_Hi);
return Failure;
elsif not Others_Present then
Hi_Val := Expr_Value (Table (J).Choice_Hi);
Lo_Val := Expr_Value (Table (J + 1).Choice_Lo);
-- If missing values, output error messages
if Lo_Val - Hi_Val > 1 then
-- Header message if not first missing value
if not Missing_Values then
Error_Msg_N
("missing index value(s) in array aggregate", N);
Missing_Values := True;
end if;
-- Output values of missing indexes
Lo_Val := Lo_Val - 1;
Hi_Val := Hi_Val + 1;
-- Enumeration type case
if Is_Enumeration_Type (Index_Typ) then
Error_Msg_Name_1 :=
Chars
(Get_Enum_Lit_From_Pos
(Index_Typ, Hi_Val, Loc));
if Lo_Val = Hi_Val then
Error_Msg_N ("\ %", N);
else
Error_Msg_Name_2 :=
Chars
(Get_Enum_Lit_From_Pos
(Index_Typ, Lo_Val, Loc));
Error_Msg_N ("\ % .. %", N);
end if;
-- Integer types case
else
Error_Msg_Uint_1 := Hi_Val;
if Lo_Val = Hi_Val then
Error_Msg_N ("\ ^", N);
else
Error_Msg_Uint_2 := Lo_Val;
Error_Msg_N ("\ ^ .. ^", N);
end if;
end if;
end if;
end if;
end loop Outer;
if Missing_Values then
Set_Etype (N, Any_Composite);
return Failure;
end if;
end if;
-- STEP 2 (B): Compute aggregate bounds and min/max choices values
if Nb_Discrete_Choices > 0 then
Choices_Low := Table (1).Choice_Lo;
Choices_High := Table (Nb_Discrete_Choices).Choice_Hi;
end if;
if Others_Present then
Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
else
Aggr_Low := Choices_Low;
Aggr_High := Choices_High;
end if;
end Step_2;
-- STEP 3: Process positional components
else
-- STEP 3 (A): Process positional elements
Expr := First (Expressions (N));
Nb_Elements := Uint_0;
while Present (Expr) loop
Nb_Elements := Nb_Elements + 1;
if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
return Failure;
end if;
Next (Expr);
end loop;
if Others_Present then
Assoc := Last (Component_Associations (N));
-- Ada0Y (AI-287): In case of default initialized component
-- we delay the resolution to the expansion phase.
if Box_Present (Assoc) then
-- Ada0Y (AI-287): In case of default initialization of a
-- component the expander will generate calls to the
-- corresponding initialization subprogram.
if Present (Base_Init_Proc (Etype (Component_Typ))) then
null;
else
Error_Msg_N
("(Ada 0Y): no value supplied for these components",
Assoc);
end if;
elsif not Resolve_Aggr_Expr (Expression (Assoc),
Single_Elmt => False)
then
return Failure;
end if;
end if;
-- STEP 3 (B): Compute the aggregate bounds
if Others_Present then
Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
else
if Others_Allowed then
Get_Index_Bounds (Index_Constr, Aggr_Low, Who_Cares);
else
Aggr_Low := Index_Typ_Low;
end if;
Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
Check_Bound (Index_Base_High, Aggr_High);
end if;
end if;
-- STEP 4: Perform static aggregate checks and save the bounds
-- Check (A)
Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
-- Check (B)
if Others_Present and then Nb_Discrete_Choices > 0 then
Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
Check_Bounds (Index_Typ_Low, Index_Typ_High,
Choices_Low, Choices_High);
Check_Bounds (Index_Base_Low, Index_Base_High,
Choices_Low, Choices_High);
-- Check (C)
elsif Others_Present and then Nb_Elements > 0 then
Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
end if;
if Raises_Constraint_Error (Aggr_Low)
or else Raises_Constraint_Error (Aggr_High)
then
Set_Raises_Constraint_Error (N);
end if;
Aggr_Low := Duplicate_Subexpr (Aggr_Low);
-- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
-- since the addition node returned by Add is not yet analyzed. Attach
-- to tree and analyze first. Reset analyzed flag to insure it will get
-- analyzed when it is a literal bound whose type must be properly
-- set.
if Others_Present or else Nb_Discrete_Choices > 0 then
Aggr_High := Duplicate_Subexpr (Aggr_High);
if Etype (Aggr_High) = Universal_Integer then
Set_Analyzed (Aggr_High, False);
end if;
end if;
Set_Aggregate_Bounds
(N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
-- The bounds may contain expressions that must be inserted upwards.
-- Attach them fully to the tree. After analysis, remove side effects
-- from upper bound, if still needed.
Set_Parent (Aggregate_Bounds (N), N);
Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
Check_Unset_Reference (Aggregate_Bounds (N));
if not Others_Present and then Nb_Discrete_Choices = 0 then
Set_High_Bound (Aggregate_Bounds (N),
Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
end if;
return Success;
end Resolve_Array_Aggregate;
---------------------------------
-- Resolve_Extension_Aggregate --
---------------------------------
-- There are two cases to consider:
-- a) If the ancestor part is a type mark, the components needed are
-- the difference between the components of the expected type and the
-- components of the given type mark.
-- b) If the ancestor part is an expression, it must be unambiguous,
-- and once we have its type we can also compute the needed components
-- as in the previous case. In both cases, if the ancestor type is not
-- the immediate ancestor, we have to build this ancestor recursively.
-- In both cases discriminants of the ancestor type do not play a
-- role in the resolution of the needed components, because inherited
-- discriminants cannot be used in a type extension. As a result we can
-- compute independently the list of components of the ancestor type and
-- of the expected type.
procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
A : constant Node_Id := Ancestor_Part (N);
A_Type : Entity_Id;
I : Interp_Index;
It : Interp;
function Valid_Ancestor_Type return Boolean;
-- Verify that the type of the ancestor part is a non-private ancestor
-- of the expected type.
-------------------------
-- Valid_Ancestor_Type --
-------------------------
function Valid_Ancestor_Type return Boolean is
Imm_Type : Entity_Id;
begin
Imm_Type := Base_Type (Typ);
while Is_Derived_Type (Imm_Type)
and then Etype (Imm_Type) /= Base_Type (A_Type)
loop
Imm_Type := Etype (Base_Type (Imm_Type));
end loop;
if Etype (Imm_Type) /= Base_Type (A_Type) then
Error_Msg_NE ("expect ancestor type of &", A, Typ);
return False;
else
return True;
end if;
end Valid_Ancestor_Type;
-- Start of processing for Resolve_Extension_Aggregate
begin
Analyze (A);
if not Is_Tagged_Type (Typ) then
Error_Msg_N ("type of extension aggregate must be tagged", N);
return;
elsif Is_Limited_Type (Typ) then
-- Ada0Y (AI-287): Limited aggregates are allowed
if Extensions_Allowed then
null;
else
Error_Msg_N ("aggregate type cannot be limited", N);
Explain_Limited_Type (Typ, N);
return;
end if;
elsif Is_Class_Wide_Type (Typ) then
Error_Msg_N ("aggregate cannot be of a class-wide type", N);
return;
end if;
if Is_Entity_Name (A)
and then Is_Type (Entity (A))
then
A_Type := Get_Full_View (Entity (A));
if Valid_Ancestor_Type then
Set_Entity (A, A_Type);
Set_Etype (A, A_Type);
Validate_Ancestor_Part (N);
Resolve_Record_Aggregate (N, Typ);
end if;
elsif Nkind (A) /= N_Aggregate then
if Is_Overloaded (A) then
A_Type := Any_Type;
Get_First_Interp (A, I, It);
while Present (It.Typ) loop
if Is_Tagged_Type (It.Typ)
and then not Is_Limited_Type (It.Typ)
then
if A_Type /= Any_Type then
Error_Msg_N ("cannot resolve expression", A);
return;
else
A_Type := It.Typ;
end if;
end if;
Get_Next_Interp (I, It);
end loop;
if A_Type = Any_Type then
Error_Msg_N
("ancestor part must be non-limited tagged type", A);
return;
end if;
else
A_Type := Etype (A);
end if;
if Valid_Ancestor_Type then
Resolve (A, A_Type);
Check_Unset_Reference (A);
Check_Non_Static_Context (A);
if Is_Class_Wide_Type (Etype (A))
and then Nkind (Original_Node (A)) = N_Function_Call
then
-- If the ancestor part is a dispatching call, it appears
-- statically to be a legal ancestor, but it yields any
-- member of the class, and it is not possible to determine
-- whether it is an ancestor of the extension aggregate (much
-- less which ancestor). It is not possible to determine the
-- required components of the extension part.
Error_Msg_N ("ancestor part must be statically tagged", A);
else
Resolve_Record_Aggregate (N, Typ);
end if;
end if;
else
Error_Msg_N (" No unique type for this aggregate", A);
end if;
end Resolve_Extension_Aggregate;
------------------------------
-- Resolve_Record_Aggregate --
------------------------------
procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
New_Assoc_List : constant List_Id := New_List;
New_Assoc : Node_Id;
-- New_Assoc_List is the newly built list of N_Component_Association
-- nodes. New_Assoc is one such N_Component_Association node in it.
-- Please note that while Assoc and New_Assoc contain the same
-- kind of nodes, they are used to iterate over two different
-- N_Component_Association lists.
Others_Etype : Entity_Id := Empty;
-- This variable is used to save the Etype of the last record component
-- that takes its value from the others choice. Its purpose is:
--
-- (a) make sure the others choice is useful
--
-- (b) make sure the type of all the components whose value is
-- subsumed by the others choice are the same.
--
-- This variable is updated as a side effect of function Get_Value
Mbox_Present : Boolean := False;
Others_Mbox : Boolean := False;
-- Ada0Y (AI-287): Variables used in case of default initialization to
-- provide a functionality similar to Others_Etype. Mbox_Present
-- indicates that the component takes its default initialization;
-- Others_Mbox indicates that at least one component takes its default
-- initialization. Similar to Others_Etype, they are also updated as a
-- side effect of function Get_Value.
procedure Add_Association
(Component : Entity_Id;
Expr : Node_Id;
Box_Present : Boolean := False);
-- Builds a new N_Component_Association node which associates
-- Component to expression Expr and adds it to the new association
-- list New_Assoc_List being built.
function Discr_Present (Discr : Entity_Id) return Boolean;
-- If aggregate N is a regular aggregate this routine will return True.
-- Otherwise, if N is an extension aggregate, Discr is a discriminant
-- whose value may already have been specified by N's ancestor part,
-- this routine checks whether this is indeed the case and if so
-- returns False, signaling that no value for Discr should appear in the
-- N's aggregate part. Also, in this case, the routine appends to
-- New_Assoc_List Discr the discriminant value specified in the ancestor
-- part.
function Get_Value
(Compon : Node_Id;
From : List_Id;
Consider_Others_Choice : Boolean := False)
return Node_Id;
-- Given a record component stored in parameter Compon, the
-- following function returns its value as it appears in the list
-- From, which is a list of N_Component_Association nodes. If no
-- component association has a choice for the searched component,
-- the value provided by the others choice is returned, if there
-- is one and Consider_Others_Choice is set to true. Otherwise
-- Empty is returned. If there is more than one component association
-- giving a value for the searched record component, an error message
-- is emitted and the first found value is returned.
--
-- If Consider_Others_Choice is set and the returned expression comes
-- from the others choice, then Others_Etype is set as a side effect.
-- An error message is emitted if the components taking their value
-- from the others choice do not have same type.
procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
-- Analyzes and resolves expression Expr against the Etype of the
-- Component. This routine also applies all appropriate checks to Expr.
-- It finally saves a Expr in the newly created association list that
-- will be attached to the final record aggregate. Note that if the
-- Parent pointer of Expr is not set then Expr was produced with a
-- New_Copy_Tree or some such.
---------------------
-- Add_Association --
---------------------
procedure Add_Association
(Component : Entity_Id;
Expr : Node_Id;
Box_Present : Boolean := False)
is
Choice_List : constant List_Id := New_List;
New_Assoc : Node_Id;
begin
Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List);
New_Assoc :=
Make_Component_Association (Sloc (Expr),
Choices => Choice_List,
Expression => Expr,
Box_Present => Box_Present);
Append (New_Assoc, New_Assoc_List);
end Add_Association;
-------------------
-- Discr_Present --
-------------------
function Discr_Present (Discr : Entity_Id) return Boolean is
Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
Loc : Source_Ptr;
Ancestor : Node_Id;
Discr_Expr : Node_Id;
Ancestor_Typ : Entity_Id;
Orig_Discr : Entity_Id;
D : Entity_Id;
D_Val : Elmt_Id := No_Elmt; -- stop junk warning
Ancestor_Is_Subtyp : Boolean;
begin
if Regular_Aggr then
return True;
end if;
Ancestor := Ancestor_Part (N);
Ancestor_Typ := Etype (Ancestor);
Loc := Sloc (Ancestor);
Ancestor_Is_Subtyp :=
Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
-- If the ancestor part has no discriminants clearly N's aggregate
-- part must provide a value for Discr.
if not Has_Discriminants (Ancestor_Typ) then
return True;
-- If the ancestor part is an unconstrained subtype mark then the
-- Discr must be present in N's aggregate part.
elsif Ancestor_Is_Subtyp
and then not Is_Constrained (Entity (Ancestor))
then
return True;
end if;
-- Now look to see if Discr was specified in the ancestor part.
Orig_Discr := Original_Record_Component (Discr);
D := First_Discriminant (Ancestor_Typ);
if Ancestor_Is_Subtyp then
D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
end if;
while Present (D) loop
-- If Ancestor has already specified Disc value than
-- insert its value in the final aggregate.
if Original_Record_Component (D) = Orig_Discr then
if Ancestor_Is_Subtyp then
Discr_Expr := New_Copy_Tree (Node (D_Val));
else
Discr_Expr :=
Make_Selected_Component (Loc,
Prefix => Duplicate_Subexpr (Ancestor),
Selector_Name => New_Occurrence_Of (Discr, Loc));
end if;
Resolve_Aggr_Expr (Discr_Expr, Discr);
return False;
end if;
Next_Discriminant (D);
if Ancestor_Is_Subtyp then
Next_Elmt (D_Val);
end if;
end loop;
return True;
end Discr_Present;
---------------
-- Get_Value --
---------------
function Get_Value
(Compon : Node_Id;
From : List_Id;
Consider_Others_Choice : Boolean := False)
return Node_Id
is
Assoc : Node_Id;
Expr : Node_Id := Empty;
Selector_Name : Node_Id;
procedure Check_Non_Limited_Type;
-- Relax check to allow the default initialization of limited types.
-- For example:
-- record
-- C : Lim := (..., others => <>);
-- end record;
----------------------------
-- Check_Non_Limited_Type --
----------------------------
procedure Check_Non_Limited_Type is
begin
if Is_Limited_Type (Etype (Compon))
and then Comes_From_Source (Compon)
and then not In_Instance_Body
then
-- Ada0Y (AI-287): Limited aggregates are allowed
if Extensions_Allowed
and then Present (Expression (Assoc))
and then Nkind (Expression (Assoc)) = N_Aggregate
then
null;
else
Error_Msg_N
("initialization not allowed for limited types", N);
Explain_Limited_Type (Etype (Compon), Compon);
end if;
end if;
end Check_Non_Limited_Type;
-- Start of processing for Get_Value
begin
Mbox_Present := False;
if Present (From) then
Assoc := First (From);
else
return Empty;
end if;
while Present (Assoc) loop
Selector_Name := First (Choices (Assoc));
while Present (Selector_Name) loop
if Nkind (Selector_Name) = N_Others_Choice then
if Consider_Others_Choice and then No (Expr) then
-- We need to duplicate the expression for each
-- successive component covered by the others choice.
-- This is redundant if the others_choice covers only
-- one component (small optimization possible???), but
-- indispensable otherwise, because each one must be
-- expanded individually to preserve side-effects.
-- Ada0Y (AI-287): In case of default initialization of
-- components, we duplicate the corresponding default
-- expression (from the record type declaration).
if Box_Present (Assoc) then
Others_Mbox := True;
Mbox_Present := True;
if Expander_Active then
return New_Copy_Tree (Expression (Parent (Compon)));
else
return Expression (Parent (Compon));
end if;
else
Check_Non_Limited_Type;
if Present (Others_Etype) and then
Base_Type (Others_Etype) /= Base_Type (Etype
(Compon))
then
Error_Msg_N ("components in OTHERS choice must " &
"have same type", Selector_Name);
end if;
Others_Etype := Etype (Compon);
if Expander_Active then
return New_Copy_Tree (Expression (Assoc));
else
return Expression (Assoc);
end if;
end if;
end if;
elsif Chars (Compon) = Chars (Selector_Name) then
if No (Expr) then
-- We need to duplicate the expression when several
-- components are grouped together with a "|" choice.
-- For instance "filed1 | filed2 => Expr"
if Box_Present (Assoc) then
Mbox_Present := True;
-- Duplicate the default expression of the component
-- from the record type declaration
if Present (Next (Selector_Name)) then
Expr := New_Copy_Tree
(Expression (Parent (Compon)));
else
Expr := Expression (Parent (Compon));
end if;
else
Check_Non_Limited_Type;
if Present (Next (Selector_Name)) then
Expr := New_Copy_Tree (Expression (Assoc));
else
Expr := Expression (Assoc);
end if;
end if;
Generate_Reference (Compon, Selector_Name);
else
Error_Msg_NE
("more than one value supplied for &",
Selector_Name, Compon);
end if;
end if;
Next (Selector_Name);
end loop;
Next (Assoc);
end loop;
return Expr;
end Get_Value;
-----------------------
-- Resolve_Aggr_Expr --
-----------------------
procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
New_C : Entity_Id := Component;
Expr_Type : Entity_Id := Empty;
function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
-- If the expression is an aggregate (possibly qualified) then its
-- expansion is delayed until the enclosing aggregate is expanded
-- into assignments. In that case, do not generate checks on the
-- expression, because they will be generated later, and will other-
-- wise force a copy (to remove side-effects) that would leave a
-- dynamic-sized aggregate in the code, something that gigi cannot
-- handle.
Relocate : Boolean;
-- Set to True if the resolved Expr node needs to be relocated
-- when attached to the newly created association list. This node
-- need not be relocated if its parent pointer is not set.
-- In fact in this case Expr is the output of a New_Copy_Tree call.
-- if Relocate is True then we have analyzed the expression node
-- in the original aggregate and hence it needs to be relocated
-- when moved over the new association list.
function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
Kind : constant Node_Kind := Nkind (Expr);
begin
return ((Kind = N_Aggregate
or else Kind = N_Extension_Aggregate)
and then Present (Etype (Expr))
and then Is_Record_Type (Etype (Expr))
and then Expansion_Delayed (Expr))
or else (Kind = N_Qualified_Expression
and then Has_Expansion_Delayed (Expression (Expr)));
end Has_Expansion_Delayed;
-- Start of processing for Resolve_Aggr_Expr
begin
-- If the type of the component is elementary or the type of the
-- aggregate does not contain discriminants, use the type of the
-- component to resolve Expr.
if Is_Elementary_Type (Etype (Component))
or else not Has_Discriminants (Etype (N))
then
Expr_Type := Etype (Component);
-- Otherwise we have to pick up the new type of the component from
-- the new costrained subtype of the aggregate. In fact components
-- which are of a composite type might be constrained by a
-- discriminant, and we want to resolve Expr against the subtype were
-- all discriminant occurrences are replaced with their actual value.
else
New_C := First_Component (Etype (N));
while Present (New_C) loop
if Chars (New_C) = Chars (Component) then
Expr_Type := Etype (New_C);
exit;
end if;
Next_Component (New_C);
end loop;
pragma Assert (Present (Expr_Type));
-- For each range in an array type where a discriminant has been
-- replaced with the constraint, check that this range is within
-- the range of the base type. This checks is done in the
-- init proc for regular objects, but has to be done here for
-- aggregates since no init proc is called for them.
if Is_Array_Type (Expr_Type) then
declare
Index : Node_Id := First_Index (Expr_Type);
-- Range of the current constrained index in the array.
Orig_Index : Node_Id := First_Index (Etype (Component));
-- Range corresponding to the range Index above in the
-- original unconstrained record type. The bounds of this
-- range may be governed by discriminants.
Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
-- Range corresponding to the range Index above for the
-- unconstrained array type. This range is needed to apply
-- range checks.
begin
while Present (Index) loop
if Depends_On_Discriminant (Orig_Index) then
Apply_Range_Check (Index, Etype (Unconstr_Index));
end if;
Next_Index (Index);
Next_Index (Orig_Index);
Next_Index (Unconstr_Index);
end loop;
end;
end if;
end if;
-- If the Parent pointer of Expr is not set, Expr is an expression
-- duplicated by New_Tree_Copy (this happens for record aggregates
-- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
-- Such a duplicated expression must be attached to the tree
-- before analysis and resolution to enforce the rule that a tree
-- fragment should never be analyzed or resolved unless it is
-- attached to the current compilation unit.
if No (Parent (Expr)) then
Set_Parent (Expr, N);
Relocate := False;
else
Relocate := True;
end if;
Analyze_And_Resolve (Expr, Expr_Type);
Check_Non_Static_Context (Expr);
Check_Unset_Reference (Expr);
if not Has_Expansion_Delayed (Expr) then
Aggregate_Constraint_Checks (Expr, Expr_Type);
end if;
if Raises_Constraint_Error (Expr) then
Set_Raises_Constraint_Error (N);
end if;
if Relocate then
Add_Association (New_C, Relocate_Node (Expr));
else
Add_Association (New_C, Expr);
end if;
end Resolve_Aggr_Expr;
-- Resolve_Record_Aggregate local variables
Assoc : Node_Id;
-- N_Component_Association node belonging to the input aggregate N
Expr : Node_Id;
Positional_Expr : Node_Id;
Component : Entity_Id;
Component_Elmt : Elmt_Id;
Components : constant Elist_Id := New_Elmt_List;
-- Components is the list of the record components whose value must
-- be provided in the aggregate. This list does include discriminants.
-- Start of processing for Resolve_Record_Aggregate
begin
-- We may end up calling Duplicate_Subexpr on expressions that are
-- attached to New_Assoc_List. For this reason we need to attach it
-- to the tree by setting its parent pointer to N. This parent point
-- will change in STEP 8 below.
Set_Parent (New_Assoc_List, N);
-- STEP 1: abstract type and null record verification
if Is_Abstract (Typ) then
Error_Msg_N ("type of aggregate cannot be abstract", N);
end if;
if No (First_Entity (Typ)) and then Null_Record_Present (N) then
Set_Etype (N, Typ);
return;
elsif Present (First_Entity (Typ))
and then Null_Record_Present (N)
and then not Is_Tagged_Type (Typ)
then
Error_Msg_N ("record aggregate cannot be null", N);
return;
elsif No (First_Entity (Typ)) then
Error_Msg_N ("record aggregate must be null", N);
return;
end if;
-- STEP 2: Verify aggregate structure
Step_2 : declare
Selector_Name : Node_Id;
Bad_Aggregate : Boolean := False;
begin
if Present (Component_Associations (N)) then
Assoc := First (Component_Associations (N));
else
Assoc := Empty;
end if;
while Present (Assoc) loop
Selector_Name := First (Choices (Assoc));
while Present (Selector_Name) loop
if Nkind (Selector_Name) = N_Identifier then
null;
elsif Nkind (Selector_Name) = N_Others_Choice then
if Selector_Name /= First (Choices (Assoc))
or else Present (Next (Selector_Name))
then
Error_Msg_N ("OTHERS must appear alone in a choice list",
Selector_Name);
return;
elsif Present (Next (Assoc)) then
Error_Msg_N ("OTHERS must appear last in an aggregate",
Selector_Name);
return;
end if;
else
Error_Msg_N
("selector name should be identifier or OTHERS",
Selector_Name);
Bad_Aggregate := True;
end if;
Next (Selector_Name);
end loop;
Next (Assoc);
end loop;
if Bad_Aggregate then
return;
end if;
end Step_2;
-- STEP 3: Find discriminant Values
Step_3 : declare
Discrim : Entity_Id;
Missing_Discriminants : Boolean := False;
begin
if Present (Expressions (N)) then
Positional_Expr := First (Expressions (N));
else
Positional_Expr := Empty;
end if;
if Has_Discriminants (Typ) then
Discrim := First_Discriminant (Typ);
else
Discrim := Empty;
end if;
-- First find the discriminant values in the positional components
while Present (Discrim) and then Present (Positional_Expr) loop
if Discr_Present (Discrim) then
Resolve_Aggr_Expr (Positional_Expr, Discrim);
Next (Positional_Expr);
end if;
if Present (Get_Value (Discrim, Component_Associations (N))) then
Error_Msg_NE
("more than one value supplied for discriminant&",
N, Discrim);
end if;
Next_Discriminant (Discrim);
end loop;
-- Find remaining discriminant values, if any, among named components
while Present (Discrim) loop
Expr := Get_Value (Discrim, Component_Associations (N), True);
if not Discr_Present (Discrim) then
if Present (Expr) then
Error_Msg_NE
("more than one value supplied for discriminant&",
N, Discrim);
end if;
elsif No (Expr) then
Error_Msg_NE
("no value supplied for discriminant &", N, Discrim);
Missing_Discriminants := True;
else
Resolve_Aggr_Expr (Expr, Discrim);
end if;
Next_Discriminant (Discrim);
end loop;
if Missing_Discriminants then
return;
end if;
-- At this point and until the beginning of STEP 6, New_Assoc_List
-- contains only the discriminants and their values.
end Step_3;
-- STEP 4: Set the Etype of the record aggregate
-- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
-- routine should really be exported in sem_util or some such and used
-- in sem_ch3 and here rather than have a copy of the code which is a
-- maintenance nightmare.
-- ??? Performace WARNING. The current implementation creates a new
-- itype for all aggregates whose base type is discriminated.
-- This means that for record aggregates nested inside an array
-- aggregate we will create a new itype for each record aggregate
-- if the array cmponent type has discriminants. For large aggregates
-- this may be a problem. What should be done in this case is
-- to reuse itypes as much as possible.
if Has_Discriminants (Typ) then
Build_Constrained_Itype : declare
Loc : constant Source_Ptr := Sloc (N);
Indic : Node_Id;
Subtyp_Decl : Node_Id;
Def_Id : Entity_Id;
C : constant List_Id := New_List;
begin
New_Assoc := First (New_Assoc_List);
while Present (New_Assoc) loop
Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
Next (New_Assoc);
end loop;
Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc),
Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
Def_Id := Create_Itype (Ekind (Typ), N);
Subtyp_Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Indication => Indic);
Set_Parent (Subtyp_Decl, Parent (N));
-- Itypes must be analyzed with checks off (see itypes.ads).
Analyze (Subtyp_Decl, Suppress => All_Checks);
Set_Etype (N, Def_Id);
Check_Static_Discriminated_Subtype
(Def_Id, Expression (First (New_Assoc_List)));
end Build_Constrained_Itype;
else
Set_Etype (N, Typ);
end if;
-- STEP 5: Get remaining components according to discriminant values
Step_5 : declare
Record_Def : Node_Id;
Parent_Typ : Entity_Id;
Root_Typ : Entity_Id;
Parent_Typ_List : Elist_Id;
Parent_Elmt : Elmt_Id;
Errors_Found : Boolean := False;
Dnode : Node_Id;
begin
if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
Parent_Typ_List := New_Elmt_List;
-- If this is an extension aggregate, the component list must
-- include all components that are not in the given ancestor
-- type. Otherwise, the component list must include components
-- of all ancestors, starting with the root.
if Nkind (N) = N_Extension_Aggregate then
Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
else
Root_Typ := Root_Type (Typ);
if Nkind (Parent (Base_Type (Root_Typ)))
= N_Private_Type_Declaration
then
Error_Msg_NE
("type of aggregate has private ancestor&!",
N, Root_Typ);
Error_Msg_N ("must use extension aggregate!", N);
return;
end if;
Dnode := Declaration_Node (Base_Type (Root_Typ));
-- If we don't get a full declaration, then we have some
-- error which will get signalled later so skip this part.
-- Otherwise, gather components of root that apply to the
-- aggregate type. We use the base type in case there is an
-- applicable stored constraint that renames the discriminants
-- of the root.
if Nkind (Dnode) = N_Full_Type_Declaration then
Record_Def := Type_Definition (Dnode);
Gather_Components (Base_Type (Typ),
Component_List (Record_Def),
Governed_By => New_Assoc_List,
Into => Components,
Report_Errors => Errors_Found);
end if;
end if;
Parent_Typ := Base_Type (Typ);
while Parent_Typ /= Root_Typ loop
Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
Parent_Typ := Etype (Parent_Typ);
if Nkind (Parent (Base_Type (Parent_Typ))) =
N_Private_Type_Declaration
or else Nkind (Parent (Base_Type (Parent_Typ))) =
N_Private_Extension_Declaration
then
if Nkind (N) /= N_Extension_Aggregate then
Error_Msg_NE
("type of aggregate has private ancestor&!",
N, Parent_Typ);
Error_Msg_N ("must use extension aggregate!", N);
return;
elsif Parent_Typ /= Root_Typ then
Error_Msg_NE
("ancestor part of aggregate must be private type&",
Ancestor_Part (N), Parent_Typ);
return;
end if;
end if;
end loop;
-- Now collect components from all other ancestors.
Parent_Elmt := First_Elmt (Parent_Typ_List);
while Present (Parent_Elmt) loop
Parent_Typ := Node (Parent_Elmt);
Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
Gather_Components (Empty,
Component_List (Record_Extension_Part (Record_Def)),
Governed_By => New_Assoc_List,
Into => Components,
Report_Errors => Errors_Found);
Next_Elmt (Parent_Elmt);
end loop;
else
Record_Def := Type_Definition (Parent (Base_Type (Typ)));
if Null_Present (Record_Def) then
null;
else
Gather_Components (Base_Type (Typ),
Component_List (Record_Def),
Governed_By => New_Assoc_List,
Into => Components,
Report_Errors => Errors_Found);
end if;
end if;
if Errors_Found then
return;
end if;
end Step_5;
-- STEP 6: Find component Values
Component := Empty;
Component_Elmt := First_Elmt (Components);
-- First scan the remaining positional associations in the aggregate.
-- Remember that at this point Positional_Expr contains the current
-- positional association if any is left after looking for discriminant
-- values in step 3.
while Present (Positional_Expr) and then Present (Component_Elmt) loop
Component := Node (Component_Elmt);
Resolve_Aggr_Expr (Positional_Expr, Component);
if Present (Get_Value (Component, Component_Associations (N))) then
Error_Msg_NE
("more than one value supplied for Component &", N, Component);
end if;
Next (Positional_Expr);
Next_Elmt (Component_Elmt);
end loop;
if Present (Positional_Expr) then
Error_Msg_N
("too many components for record aggregate", Positional_Expr);
end if;
-- Now scan for the named arguments of the aggregate
while Present (Component_Elmt) loop
Component := Node (Component_Elmt);
Expr := Get_Value (Component, Component_Associations (N), True);
if Mbox_Present and then Is_Limited_Type (Etype (Component)) then
-- Ada0Y (AI-287): In case of default initialization of a limited
-- component we pass the limited component to the expander. The
-- expander will generate calls to the corresponding initiali-
-- zation subprograms.
Add_Association
(Component => Component,
Expr => Empty,
Box_Present => True);
elsif No (Expr) then
Error_Msg_NE ("no value supplied for component &!", N, Component);
else
Resolve_Aggr_Expr (Expr, Component);
end if;
Next_Elmt (Component_Elmt);
end loop;
-- STEP 7: check for invalid components + check type in choice list
Step_7 : declare
Selectr : Node_Id;
-- Selector name
Typech : Entity_Id;
-- Type of first component in choice list
begin
if Present (Component_Associations (N)) then
Assoc := First (Component_Associations (N));
else
Assoc := Empty;
end if;
Verification : while Present (Assoc) loop
Selectr := First (Choices (Assoc));
Typech := Empty;
if Nkind (Selectr) = N_Others_Choice then
-- Ada0Y (AI-287): others choice may have expression or mbox
if No (Others_Etype)
and then not Others_Mbox
then
Error_Msg_N
("OTHERS must represent at least one component", Selectr);
end if;
exit Verification;
end if;
while Present (Selectr) loop
New_Assoc := First (New_Assoc_List);
while Present (New_Assoc) loop
Component := First (Choices (New_Assoc));
exit when Chars (Selectr) = Chars (Component);
Next (New_Assoc);
end loop;
-- If no association, this is not a legal component of
-- of the type in question, except if this is an internal
-- component supplied by a previous expansion.
if No (New_Assoc) then
if Box_Present (Parent (Selectr)) then
null;
elsif Chars (Selectr) /= Name_uTag
and then Chars (Selectr) /= Name_uParent
and then Chars (Selectr) /= Name_uController
then
if not Has_Discriminants (Typ) then
Error_Msg_Node_2 := Typ;
Error_Msg_N
("& is not a component of}",
Selectr);
else
Error_Msg_N
("& is not a component of the aggregate subtype",
Selectr);
end if;
Check_Misspelled_Component (Components, Selectr);
end if;
elsif No (Typech) then
Typech := Base_Type (Etype (Component));
elsif Typech /= Base_Type (Etype (Component)) then
if not Box_Present (Parent (Selectr)) then
Error_Msg_N
("components in choice list must have same type",
Selectr);
end if;
end if;
Next (Selectr);
end loop;
Next (Assoc);
end loop Verification;
end Step_7;
-- STEP 8: replace the original aggregate
Step_8 : declare
New_Aggregate : constant Node_Id := New_Copy (N);
begin
Set_Expressions (New_Aggregate, No_List);
Set_Etype (New_Aggregate, Etype (N));
Set_Component_Associations (New_Aggregate, New_Assoc_List);
Rewrite (N, New_Aggregate);
end Step_8;
end Resolve_Record_Aggregate;
---------------------
-- Sort_Case_Table --
---------------------
procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
L : constant Int := Case_Table'First;
U : constant Int := Case_Table'Last;
K : Int;
J : Int;
T : Case_Bounds;
begin
K := L;
while K /= U loop
T := Case_Table (K + 1);
J := K + 1;
while J /= L
and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
Expr_Value (T.Choice_Lo)
loop
Case_Table (J) := Case_Table (J - 1);
J := J - 1;
end loop;
Case_Table (J) := T;
K := K + 1;
end loop;
end Sort_Case_Table;
end Sem_Aggr;