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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ C H 4 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2013, 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 Atree; use Atree;
with Checks; use Checks;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Aggr; use Exp_Aggr;
with Exp_Atag; use Exp_Atag;
with Exp_Ch2; use Exp_Ch2;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch6; use Exp_Ch6;
with Exp_Ch7; use Exp_Ch7;
with Exp_Ch9; use Exp_Ch9;
with Exp_Disp; use Exp_Disp;
with Exp_Fixd; use Exp_Fixd;
with Exp_Intr; use Exp_Intr;
with Exp_Pakd; use Exp_Pakd;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Exp_VFpt; use Exp_VFpt;
with Freeze; use Freeze;
with Inline; use Inline;
with Lib; use Lib;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Par_SCO; use Par_SCO;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
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_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with SCIL_LL; use SCIL_LL;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Uintp; use Uintp;
with Urealp; use Urealp;
with Validsw; use Validsw;
package body Exp_Ch4 is
-----------------------
-- Local Subprograms --
-----------------------
procedure Binary_Op_Validity_Checks (N : Node_Id);
pragma Inline (Binary_Op_Validity_Checks);
-- Performs validity checks for a binary operator
procedure Build_Boolean_Array_Proc_Call
(N : Node_Id;
Op1 : Node_Id;
Op2 : Node_Id);
-- If a boolean array assignment can be done in place, build call to
-- corresponding library procedure.
function Current_Anonymous_Master return Entity_Id;
-- Return the entity of the heterogeneous finalization master belonging to
-- the current unit (either function, package or procedure). This master
-- services all anonymous access-to-controlled types. If the current unit
-- does not have such master, create one.
procedure Displace_Allocator_Pointer (N : Node_Id);
-- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and
-- Expand_Allocator_Expression. Allocating class-wide interface objects
-- this routine displaces the pointer to the allocated object to reference
-- the component referencing the corresponding secondary dispatch table.
procedure Expand_Allocator_Expression (N : Node_Id);
-- Subsidiary to Expand_N_Allocator, for the case when the expression
-- is a qualified expression or an aggregate.
procedure Expand_Array_Comparison (N : Node_Id);
-- This routine handles expansion of the comparison operators (N_Op_Lt,
-- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic
-- code for these operators is similar, differing only in the details of
-- the actual comparison call that is made. Special processing (call a
-- run-time routine)
function Expand_Array_Equality
(Nod : Node_Id;
Lhs : Node_Id;
Rhs : Node_Id;
Bodies : List_Id;
Typ : Entity_Id) return Node_Id;
-- Expand an array equality into a call to a function implementing this
-- equality, and a call to it. Loc is the location for the generated nodes.
-- Lhs and Rhs are the array expressions to be compared. Bodies is a list
-- on which to attach bodies of local functions that are created in the
-- process. It is the responsibility of the caller to insert those bodies
-- at the right place. Nod provides the Sloc value for the generated code.
-- Normally the types used for the generated equality routine are taken
-- from Lhs and Rhs. However, in some situations of generated code, the
-- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies
-- the type to be used for the formal parameters.
procedure Expand_Boolean_Operator (N : Node_Id);
-- Common expansion processing for Boolean operators (And, Or, Xor) for the
-- case of array type arguments.
procedure Expand_Short_Circuit_Operator (N : Node_Id);
-- Common expansion processing for short-circuit boolean operators
procedure Expand_Compare_Minimize_Eliminate_Overflow (N : Node_Id);
-- Deal with comparison in MINIMIZED/ELIMINATED overflow mode. This is
-- where we allow comparison of "out of range" values.
function Expand_Composite_Equality
(Nod : Node_Id;
Typ : Entity_Id;
Lhs : Node_Id;
Rhs : Node_Id;
Bodies : List_Id) return Node_Id;
-- Local recursive function used to expand equality for nested composite
-- types. Used by Expand_Record/Array_Equality, Bodies is a list on which
-- to attach bodies of local functions that are created in the process.
-- It is the responsibility of the caller to insert those bodies at the
-- right place. Nod provides the Sloc value for generated code. Lhs and Rhs
-- are the left and right sides for the comparison, and Typ is the type of
-- the objects to compare.
procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id);
-- Routine to expand concatenation of a sequence of two or more operands
-- (in the list Operands) and replace node Cnode with the result of the
-- concatenation. The operands can be of any appropriate type, and can
-- include both arrays and singleton elements.
procedure Expand_Membership_Minimize_Eliminate_Overflow (N : Node_Id);
-- N is an N_In membership test mode, with the overflow check mode set to
-- MINIMIZED or ELIMINATED, and the type of the left operand is a signed
-- integer type. This is a case where top level processing is required to
-- handle overflow checks in subtrees.
procedure Fixup_Universal_Fixed_Operation (N : Node_Id);
-- N is a N_Op_Divide or N_Op_Multiply node whose result is universal
-- fixed. We do not have such a type at runtime, so the purpose of this
-- routine is to find the real type by looking up the tree. We also
-- determine if the operation must be rounded.
function Has_Inferable_Discriminants (N : Node_Id) return Boolean;
-- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
-- discriminants if it has a constrained nominal type, unless the object
-- is a component of an enclosing Unchecked_Union object that is subject
-- to a per-object constraint and the enclosing object lacks inferable
-- discriminants.
--
-- An expression of an Unchecked_Union type has inferable discriminants
-- if it is either a name of an object with inferable discriminants or a
-- qualified expression whose subtype mark denotes a constrained subtype.
procedure Insert_Dereference_Action (N : Node_Id);
-- N is an expression whose type is an access. When the type of the
-- associated storage pool is derived from Checked_Pool, generate a
-- call to the 'Dereference' primitive operation.
function Make_Array_Comparison_Op
(Typ : Entity_Id;
Nod : Node_Id) return Node_Id;
-- Comparisons between arrays are expanded in line. This function produces
-- the body of the implementation of (a > b), where a and b are one-
-- dimensional arrays of some discrete type. The original node is then
-- expanded into the appropriate call to this function. Nod provides the
-- Sloc value for the generated code.
function Make_Boolean_Array_Op
(Typ : Entity_Id;
N : Node_Id) return Node_Id;
-- Boolean operations on boolean arrays are expanded in line. This function
-- produce the body for the node N, which is (a and b), (a or b), or (a xor
-- b). It is used only the normal case and not the packed case. The type
-- involved, Typ, is the Boolean array type, and the logical operations in
-- the body are simple boolean operations. Note that Typ is always a
-- constrained type (the caller has ensured this by using
-- Convert_To_Actual_Subtype if necessary).
function Minimized_Eliminated_Overflow_Check (N : Node_Id) return Boolean;
-- For signed arithmetic operations when the current overflow mode is
-- MINIMIZED or ELIMINATED, we must call Apply_Arithmetic_Overflow_Checks
-- as the first thing we do. We then return. We count on the recursive
-- apparatus for overflow checks to call us back with an equivalent
-- operation that is in CHECKED mode, avoiding a recursive entry into this
-- routine, and that is when we will proceed with the expansion of the
-- operator (e.g. converting X+0 to X, or X**2 to X*X). We cannot do
-- these optimizations without first making this check, since there may be
-- operands further down the tree that are relying on the recursive calls
-- triggered by the top level nodes to properly process overflow checking
-- and remaining expansion on these nodes. Note that this call back may be
-- skipped if the operation is done in Bignum mode but that's fine, since
-- the Bignum call takes care of everything.
procedure Optimize_Length_Comparison (N : Node_Id);
-- Given an expression, if it is of the form X'Length op N (or the other
-- way round), where N is known at compile time to be 0 or 1, and X is a
-- simple entity, and op is a comparison operator, optimizes it into a
-- comparison of First and Last.
procedure Rewrite_Comparison (N : Node_Id);
-- If N is the node for a comparison whose outcome can be determined at
-- compile time, then the node N can be rewritten with True or False. If
-- the outcome cannot be determined at compile time, the call has no
-- effect. If N is a type conversion, then this processing is applied to
-- its expression. If N is neither comparison nor a type conversion, the
-- call has no effect.
procedure Tagged_Membership
(N : Node_Id;
SCIL_Node : out Node_Id;
Result : out Node_Id);
-- Construct the expression corresponding to the tagged membership test.
-- Deals with a second operand being (or not) a class-wide type.
function Safe_In_Place_Array_Op
(Lhs : Node_Id;
Op1 : Node_Id;
Op2 : Node_Id) return Boolean;
-- In the context of an assignment, where the right-hand side is a boolean
-- operation on arrays, check whether operation can be performed in place.
procedure Unary_Op_Validity_Checks (N : Node_Id);
pragma Inline (Unary_Op_Validity_Checks);
-- Performs validity checks for a unary operator
-------------------------------
-- Binary_Op_Validity_Checks --
-------------------------------
procedure Binary_Op_Validity_Checks (N : Node_Id) is
begin
if Validity_Checks_On and Validity_Check_Operands then
Ensure_Valid (Left_Opnd (N));
Ensure_Valid (Right_Opnd (N));
end if;
end Binary_Op_Validity_Checks;
------------------------------------
-- Build_Boolean_Array_Proc_Call --
------------------------------------
procedure Build_Boolean_Array_Proc_Call
(N : Node_Id;
Op1 : Node_Id;
Op2 : Node_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Kind : constant Node_Kind := Nkind (Expression (N));
Target : constant Node_Id :=
Make_Attribute_Reference (Loc,
Prefix => Name (N),
Attribute_Name => Name_Address);
Arg1 : Node_Id := Op1;
Arg2 : Node_Id := Op2;
Call_Node : Node_Id;
Proc_Name : Entity_Id;
begin
if Kind = N_Op_Not then
if Nkind (Op1) in N_Binary_Op then
-- Use negated version of the binary operators
if Nkind (Op1) = N_Op_And then
Proc_Name := RTE (RE_Vector_Nand);
elsif Nkind (Op1) = N_Op_Or then
Proc_Name := RTE (RE_Vector_Nor);
else pragma Assert (Nkind (Op1) = N_Op_Xor);
Proc_Name := RTE (RE_Vector_Xor);
end if;
Call_Node :=
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Proc_Name, Loc),
Parameter_Associations => New_List (
Target,
Make_Attribute_Reference (Loc,
Prefix => Left_Opnd (Op1),
Attribute_Name => Name_Address),
Make_Attribute_Reference (Loc,
Prefix => Right_Opnd (Op1),
Attribute_Name => Name_Address),
Make_Attribute_Reference (Loc,
Prefix => Left_Opnd (Op1),
Attribute_Name => Name_Length)));
else
Proc_Name := RTE (RE_Vector_Not);
Call_Node :=
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Proc_Name, Loc),
Parameter_Associations => New_List (
Target,
Make_Attribute_Reference (Loc,
Prefix => Op1,
Attribute_Name => Name_Address),
Make_Attribute_Reference (Loc,
Prefix => Op1,
Attribute_Name => Name_Length)));
end if;
else
-- We use the following equivalences:
-- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
-- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
-- (not X) xor (not Y) = X xor Y
-- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
if Nkind (Op1) = N_Op_Not then
Arg1 := Right_Opnd (Op1);
Arg2 := Right_Opnd (Op2);
if Kind = N_Op_And then
Proc_Name := RTE (RE_Vector_Nor);
elsif Kind = N_Op_Or then
Proc_Name := RTE (RE_Vector_Nand);
else
Proc_Name := RTE (RE_Vector_Xor);
end if;
else
if Kind = N_Op_And then
Proc_Name := RTE (RE_Vector_And);
elsif Kind = N_Op_Or then
Proc_Name := RTE (RE_Vector_Or);
elsif Nkind (Op2) = N_Op_Not then
Proc_Name := RTE (RE_Vector_Nxor);
Arg2 := Right_Opnd (Op2);
else
Proc_Name := RTE (RE_Vector_Xor);
end if;
end if;
Call_Node :=
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Proc_Name, Loc),
Parameter_Associations => New_List (
Target,
Make_Attribute_Reference (Loc,
Prefix => Arg1,
Attribute_Name => Name_Address),
Make_Attribute_Reference (Loc,
Prefix => Arg2,
Attribute_Name => Name_Address),
Make_Attribute_Reference (Loc,
Prefix => Arg1,
Attribute_Name => Name_Length)));
end if;
Rewrite (N, Call_Node);
Analyze (N);
exception
when RE_Not_Available =>
return;
end Build_Boolean_Array_Proc_Call;
------------------------------
-- Current_Anonymous_Master --
------------------------------
function Current_Anonymous_Master return Entity_Id is
Decls : List_Id;
Loc : Source_Ptr;
Subp_Body : Node_Id;
Unit_Decl : Node_Id;
Unit_Id : Entity_Id;
begin
Unit_Id := Cunit_Entity (Current_Sem_Unit);
-- Find the entity of the current unit
if Ekind (Unit_Id) = E_Subprogram_Body then
-- When processing subprogram bodies, the proper scope is always that
-- of the spec.
Subp_Body := Unit_Id;
while Present (Subp_Body)
and then Nkind (Subp_Body) /= N_Subprogram_Body
loop
Subp_Body := Parent (Subp_Body);
end loop;
Unit_Id := Corresponding_Spec (Subp_Body);
end if;
Loc := Sloc (Unit_Id);
Unit_Decl := Unit (Cunit (Current_Sem_Unit));
-- Find the declarations list of the current unit
if Nkind (Unit_Decl) = N_Package_Declaration then
Unit_Decl := Specification (Unit_Decl);
Decls := Visible_Declarations (Unit_Decl);
if No (Decls) then
Decls := New_List (Make_Null_Statement (Loc));
Set_Visible_Declarations (Unit_Decl, Decls);
elsif Is_Empty_List (Decls) then
Append_To (Decls, Make_Null_Statement (Loc));
end if;
else
Decls := Declarations (Unit_Decl);
if No (Decls) then
Decls := New_List (Make_Null_Statement (Loc));
Set_Declarations (Unit_Decl, Decls);
elsif Is_Empty_List (Decls) then
Append_To (Decls, Make_Null_Statement (Loc));
end if;
end if;
-- The current unit has an existing anonymous master, traverse its
-- declarations and locate the entity.
if Has_Anonymous_Master (Unit_Id) then
declare
Decl : Node_Id;
Fin_Mas_Id : Entity_Id;
begin
Decl := First (Decls);
while Present (Decl) loop
-- Look for the first variable in the declarations whole type
-- is Finalization_Master.
if Nkind (Decl) = N_Object_Declaration then
Fin_Mas_Id := Defining_Identifier (Decl);
if Ekind (Fin_Mas_Id) = E_Variable
and then Etype (Fin_Mas_Id) = RTE (RE_Finalization_Master)
then
return Fin_Mas_Id;
end if;
end if;
Next (Decl);
end loop;
-- The master was not found even though the unit was labeled as
-- having one.
raise Program_Error;
end;
-- Create a new anonymous master
else
declare
First_Decl : constant Node_Id := First (Decls);
Action : Node_Id;
Fin_Mas_Id : Entity_Id;
begin
-- Since the master and its associated initialization is inserted
-- at top level, use the scope of the unit when analyzing.
Push_Scope (Unit_Id);
-- Create the finalization master
Fin_Mas_Id :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (Unit_Id), "AM"));
-- Generate:
-- <Fin_Mas_Id> : Finalization_Master;
Action :=
Make_Object_Declaration (Loc,
Defining_Identifier => Fin_Mas_Id,
Object_Definition =>
New_Reference_To (RTE (RE_Finalization_Master), Loc));
Insert_Before_And_Analyze (First_Decl, Action);
-- Mark the unit to prevent the generation of multiple masters
Set_Has_Anonymous_Master (Unit_Id);
-- Do not set the base pool and mode of operation on .NET/JVM
-- since those targets do not support pools and all VM masters
-- are heterogeneous by default.
if VM_Target = No_VM then
-- Generate:
-- Set_Base_Pool
-- (<Fin_Mas_Id>, Global_Pool_Object'Unrestricted_Access);
Action :=
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (RTE (RE_Set_Base_Pool), Loc),
Parameter_Associations => New_List (
New_Reference_To (Fin_Mas_Id, Loc),
Make_Attribute_Reference (Loc,
Prefix =>
New_Reference_To (RTE (RE_Global_Pool_Object), Loc),
Attribute_Name => Name_Unrestricted_Access)));
Insert_Before_And_Analyze (First_Decl, Action);
-- Generate:
-- Set_Is_Heterogeneous (<Fin_Mas_Id>);
Action :=
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (RTE (RE_Set_Is_Heterogeneous), Loc),
Parameter_Associations => New_List (
New_Reference_To (Fin_Mas_Id, Loc)));
Insert_Before_And_Analyze (First_Decl, Action);
end if;
-- Restore the original state of the scope stack
Pop_Scope;
return Fin_Mas_Id;
end;
end if;
end Current_Anonymous_Master;
--------------------------------
-- Displace_Allocator_Pointer --
--------------------------------
procedure Displace_Allocator_Pointer (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Orig_Node : constant Node_Id := Original_Node (N);
Dtyp : Entity_Id;
Etyp : Entity_Id;
PtrT : Entity_Id;
begin
-- Do nothing in case of VM targets: the virtual machine will handle
-- interfaces directly.
if not Tagged_Type_Expansion then
return;
end if;
pragma Assert (Nkind (N) = N_Identifier
and then Nkind (Orig_Node) = N_Allocator);
PtrT := Etype (Orig_Node);
Dtyp := Available_View (Designated_Type (PtrT));
Etyp := Etype (Expression (Orig_Node));
if Is_Class_Wide_Type (Dtyp)
and then Is_Interface (Dtyp)
then
-- If the type of the allocator expression is not an interface type
-- we can generate code to reference the record component containing
-- the pointer to the secondary dispatch table.
if not Is_Interface (Etyp) then
declare
Saved_Typ : constant Entity_Id := Etype (Orig_Node);
begin
-- 1) Get access to the allocated object
Rewrite (N,
Make_Explicit_Dereference (Loc, Relocate_Node (N)));
Set_Etype (N, Etyp);
Set_Analyzed (N);
-- 2) Add the conversion to displace the pointer to reference
-- the secondary dispatch table.
Rewrite (N, Convert_To (Dtyp, Relocate_Node (N)));
Analyze_And_Resolve (N, Dtyp);
-- 3) The 'access to the secondary dispatch table will be used
-- as the value returned by the allocator.
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (N),
Attribute_Name => Name_Access));
Set_Etype (N, Saved_Typ);
Set_Analyzed (N);
end;
-- If the type of the allocator expression is an interface type we
-- generate a run-time call to displace "this" to reference the
-- component containing the pointer to the secondary dispatch table
-- or else raise Constraint_Error if the actual object does not
-- implement the target interface. This case corresponds with the
-- following example:
-- function Op (Obj : Iface_1'Class) return access Iface_2'Class is
-- begin
-- return new Iface_2'Class'(Obj);
-- end Op;
else
Rewrite (N,
Unchecked_Convert_To (PtrT,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Displace), Loc),
Parameter_Associations => New_List (
Unchecked_Convert_To (RTE (RE_Address),
Relocate_Node (N)),
New_Occurrence_Of
(Elists.Node
(First_Elmt
(Access_Disp_Table (Etype (Base_Type (Dtyp))))),
Loc)))));
Analyze_And_Resolve (N, PtrT);
end if;
end if;
end Displace_Allocator_Pointer;
---------------------------------
-- Expand_Allocator_Expression --
---------------------------------
procedure Expand_Allocator_Expression (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Exp : constant Node_Id := Expression (Expression (N));
PtrT : constant Entity_Id := Etype (N);
DesigT : constant Entity_Id := Designated_Type (PtrT);
procedure Apply_Accessibility_Check
(Ref : Node_Id;
Built_In_Place : Boolean := False);
-- Ada 2005 (AI-344): For an allocator with a class-wide designated
-- type, generate an accessibility check to verify that the level of the
-- type of the created object is not deeper than the level of the access
-- type. If the type of the qualified expression is class-wide, then
-- always generate the check (except in the case where it is known to be
-- unnecessary, see comment below). Otherwise, only generate the check
-- if the level of the qualified expression type is statically deeper
-- than the access type.
--
-- Although the static accessibility will generally have been performed
-- as a legality check, it won't have been done in cases where the
-- allocator appears in generic body, so a run-time check is needed in
-- general. One special case is when the access type is declared in the
-- same scope as the class-wide allocator, in which case the check can
-- never fail, so it need not be generated.
--
-- As an open issue, there seem to be cases where the static level
-- associated with the class-wide object's underlying type is not
-- sufficient to perform the proper accessibility check, such as for
-- allocators in nested subprograms or accept statements initialized by
-- class-wide formals when the actual originates outside at a deeper
-- static level. The nested subprogram case might require passing
-- accessibility levels along with class-wide parameters, and the task
-- case seems to be an actual gap in the language rules that needs to
-- be fixed by the ARG. ???
-------------------------------
-- Apply_Accessibility_Check --
-------------------------------
procedure Apply_Accessibility_Check
(Ref : Node_Id;
Built_In_Place : Boolean := False)
is
Pool_Id : constant Entity_Id := Associated_Storage_Pool (PtrT);
Cond : Node_Id;
Free_Stmt : Node_Id;
Obj_Ref : Node_Id;
Stmts : List_Id;
begin
if Ada_Version >= Ada_2005
and then Is_Class_Wide_Type (DesigT)
and then not Scope_Suppress.Suppress (Accessibility_Check)
and then
(Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT)
or else
(Is_Class_Wide_Type (Etype (Exp))
and then Scope (PtrT) /= Current_Scope))
and then (Tagged_Type_Expansion or else VM_Target /= No_VM)
then
-- If the allocator was built in place, Ref is already a reference
-- to the access object initialized to the result of the allocator
-- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). We call
-- Remove_Side_Effects for cases where the build-in-place call may
-- still be the prefix of the reference (to avoid generating
-- duplicate calls). Otherwise, it is the entity associated with
-- the object containing the address of the allocated object.
if Built_In_Place then
Remove_Side_Effects (Ref);
Obj_Ref := New_Copy (Ref);
else
Obj_Ref := New_Reference_To (Ref, Loc);
end if;
-- Step 1: Create the object clean up code
Stmts := New_List;
-- Create an explicit free statement to clean up the allocated
-- object in case the accessibility check fails. Generate:
-- Free (Obj_Ref);
Free_Stmt := Make_Free_Statement (Loc, New_Copy (Obj_Ref));
Set_Storage_Pool (Free_Stmt, Pool_Id);
Append_To (Stmts, Free_Stmt);
-- Finalize the object (if applicable), but wrap the call inside
-- a block to ensure that the object would still be deallocated in
-- case the finalization fails. Generate:
-- begin
-- [Deep_]Finalize (Obj_Ref.all);
-- exception
-- when others =>
-- Free (Obj_Ref);
-- raise;
-- end;
if Needs_Finalization (DesigT) then
Prepend_To (Stmts,
Make_Block_Statement (Loc,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Final_Call (
Obj_Ref =>
Make_Explicit_Dereference (Loc,
Prefix => New_Copy (Obj_Ref)),
Typ => DesigT)),
Exception_Handlers => New_List (
Make_Exception_Handler (Loc,
Exception_Choices => New_List (
Make_Others_Choice (Loc)),
Statements => New_List (
New_Copy_Tree (Free_Stmt),
Make_Raise_Statement (Loc)))))));
end if;
-- Signal the accessibility failure through a Program_Error
Append_To (Stmts,
Make_Raise_Program_Error (Loc,
Condition => New_Reference_To (Standard_True, Loc),
Reason => PE_Accessibility_Check_Failed));
-- Step 2: Create the accessibility comparison
-- Generate:
-- Ref'Tag
Obj_Ref :=
Make_Attribute_Reference (Loc,
Prefix => Obj_Ref,
Attribute_Name => Name_Tag);
-- For tagged types, determine the accessibility level by looking
-- at the type specific data of the dispatch table. Generate:
-- Type_Specific_Data (Address (Ref'Tag)).Access_Level
if Tagged_Type_Expansion then
Cond := Build_Get_Access_Level (Loc, Obj_Ref);
-- Use a runtime call to determine the accessibility level when
-- compiling on virtual machine targets. Generate:
-- Get_Access_Level (Ref'Tag)
else
Cond :=
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Get_Access_Level), Loc),
Parameter_Associations => New_List (Obj_Ref));
end if;
Cond :=
Make_Op_Gt (Loc,
Left_Opnd => Cond,
Right_Opnd =>
Make_Integer_Literal (Loc, Type_Access_Level (PtrT)));
-- Due to the complexity and side effects of the check, utilize an
-- if statement instead of the regular Program_Error circuitry.
Insert_Action (N,
Make_If_Statement (Loc,
Condition => Cond,
Then_Statements => Stmts));
end if;
end Apply_Accessibility_Check;
-- Local variables
Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp);
Indic : constant Node_Id := Subtype_Mark (Expression (N));
T : constant Entity_Id := Entity (Indic);
Node : Node_Id;
Tag_Assign : Node_Id;
Temp : Entity_Id;
Temp_Decl : Node_Id;
TagT : Entity_Id := Empty;
-- Type used as source for tag assignment
TagR : Node_Id := Empty;
-- Target reference for tag assignment
-- Start of processing for Expand_Allocator_Expression
begin
-- Handle call to C++ constructor
if Is_CPP_Constructor_Call (Exp) then
Make_CPP_Constructor_Call_In_Allocator
(Allocator => N,
Function_Call => Exp);
return;
end if;
-- In the case of an Ada 2012 allocator whose initial value comes from a
-- function call, pass "the accessibility level determined by the point
-- of call" (AI05-0234) to the function. Conceptually, this belongs in
-- Expand_Call but it couldn't be done there (because the Etype of the
-- allocator wasn't set then) so we generate the parameter here. See
-- the Boolean variable Defer in (a block within) Expand_Call.
if Ada_Version >= Ada_2012 and then Nkind (Exp) = N_Function_Call then
declare
Subp : Entity_Id;
begin
if Nkind (Name (Exp)) = N_Explicit_Dereference then
Subp := Designated_Type (Etype (Prefix (Name (Exp))));
else
Subp := Entity (Name (Exp));
end if;
Subp := Ultimate_Alias (Subp);
if Present (Extra_Accessibility_Of_Result (Subp)) then
Add_Extra_Actual_To_Call
(Subprogram_Call => Exp,
Extra_Formal => Extra_Accessibility_Of_Result (Subp),
Extra_Actual => Dynamic_Accessibility_Level (PtrT));
end if;
end;
end if;
-- Case of tagged type or type requiring finalization
if Is_Tagged_Type (T) or else Needs_Finalization (T) then
-- Ada 2005 (AI-318-02): If the initialization expression is a call
-- to a build-in-place function, then access to the allocated object
-- must be passed to the function. Currently we limit such functions
-- to those with constrained limited result subtypes, but eventually
-- we plan to expand the allowed forms of functions that are treated
-- as build-in-place.
if Ada_Version >= Ada_2005
and then Is_Build_In_Place_Function_Call (Exp)
then
Make_Build_In_Place_Call_In_Allocator (N, Exp);
Apply_Accessibility_Check (N, Built_In_Place => True);
return;
end if;
-- Actions inserted before:
-- Temp : constant ptr_T := new T'(Expression);
-- Temp._tag = T'tag; -- when not class-wide
-- [Deep_]Adjust (Temp.all);
-- We analyze by hand the new internal allocator to avoid any
-- recursion and inappropriate call to Initialize
-- We don't want to remove side effects when the expression must be
-- built in place. In the case of a build-in-place function call,
-- that could lead to a duplication of the call, which was already
-- substituted for the allocator.
if not Aggr_In_Place then
Remove_Side_Effects (Exp);
end if;
Temp := Make_Temporary (Loc, 'P', N);
-- For a class wide allocation generate the following code:
-- type Equiv_Record is record ... end record;
-- implicit subtype CW is <Class_Wide_Subytpe>;
-- temp : PtrT := new CW'(CW!(expr));
if Is_Class_Wide_Type (T) then
Expand_Subtype_From_Expr (Empty, T, Indic, Exp);
-- Ada 2005 (AI-251): If the expression is a class-wide interface
-- object we generate code to move up "this" to reference the
-- base of the object before allocating the new object.
-- Note that Exp'Address is recursively expanded into a call
-- to Base_Address (Exp.Tag)
if Is_Class_Wide_Type (Etype (Exp))
and then Is_Interface (Etype (Exp))
and then Tagged_Type_Expansion
then
Set_Expression
(Expression (N),
Unchecked_Convert_To (Entity (Indic),
Make_Explicit_Dereference (Loc,
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
Make_Attribute_Reference (Loc,
Prefix => Exp,
Attribute_Name => Name_Address)))));
else
Set_Expression
(Expression (N),
Unchecked_Convert_To (Entity (Indic), Exp));
end if;
Analyze_And_Resolve (Expression (N), Entity (Indic));
end if;
-- Processing for allocators returning non-interface types
if not Is_Interface (Directly_Designated_Type (PtrT)) then
if Aggr_In_Place then
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => New_Reference_To (PtrT, Loc),
Expression =>
Make_Allocator (Loc,
Expression =>
New_Reference_To (Etype (Exp), Loc)));
-- Copy the Comes_From_Source flag for the allocator we just
-- built, since logically this allocator is a replacement of
-- the original allocator node. This is for proper handling of
-- restriction No_Implicit_Heap_Allocations.
Set_Comes_From_Source
(Expression (Temp_Decl), Comes_From_Source (N));
Set_No_Initialization (Expression (Temp_Decl));
Insert_Action (N, Temp_Decl);
Build_Allocate_Deallocate_Proc (Temp_Decl, True);
Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
-- Attach the object to the associated finalization master.
-- This is done manually on .NET/JVM since those compilers do
-- no support pools and can't benefit from internally generated
-- Allocate / Deallocate procedures.
if VM_Target /= No_VM
and then Is_Controlled (DesigT)
and then Present (Finalization_Master (PtrT))
then
Insert_Action (N,
Make_Attach_Call (
Obj_Ref =>
New_Reference_To (Temp, Loc),
Ptr_Typ => PtrT));
end if;
else
Node := Relocate_Node (N);
Set_Analyzed (Node);
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Constant_Present => True,
Object_Definition => New_Reference_To (PtrT, Loc),
Expression => Node);
Insert_Action (N, Temp_Decl);
Build_Allocate_Deallocate_Proc (Temp_Decl, True);
-- Attach the object to the associated finalization master.
-- This is done manually on .NET/JVM since those compilers do
-- no support pools and can't benefit from internally generated
-- Allocate / Deallocate procedures.
if VM_Target /= No_VM
and then Is_Controlled (DesigT)
and then Present (Finalization_Master (PtrT))
then
Insert_Action (N,
Make_Attach_Call (
Obj_Ref =>
New_Reference_To (Temp, Loc),
Ptr_Typ => PtrT));
end if;
end if;
-- Ada 2005 (AI-251): Handle allocators whose designated type is an
-- interface type. In this case we use the type of the qualified
-- expression to allocate the object.
else
declare
Def_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
New_Decl : Node_Id;
begin
New_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Def_Id,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Null_Exclusion_Present => False,
Constant_Present =>
Is_Access_Constant (Etype (N)),
Subtype_Indication =>
New_Reference_To (Etype (Exp), Loc)));
Insert_Action (N, New_Decl);
-- Inherit the allocation-related attributes from the original
-- access type.
Set_Finalization_Master (Def_Id, Finalization_Master (PtrT));
Set_Associated_Storage_Pool (Def_Id,
Associated_Storage_Pool (PtrT));
-- Declare the object using the previous type declaration
if Aggr_In_Place then
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => New_Reference_To (Def_Id, Loc),
Expression =>
Make_Allocator (Loc,
New_Reference_To (Etype (Exp), Loc)));
-- Copy the Comes_From_Source flag for the allocator we just
-- built, since logically this allocator is a replacement of
-- the original allocator node. This is for proper handling
-- of restriction No_Implicit_Heap_Allocations.
Set_Comes_From_Source
(Expression (Temp_Decl), Comes_From_Source (N));
Set_No_Initialization (Expression (Temp_Decl));
Insert_Action (N, Temp_Decl);
Build_Allocate_Deallocate_Proc (Temp_Decl, True);
Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
else
Node := Relocate_Node (N);
Set_Analyzed (Node);
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Constant_Present => True,
Object_Definition => New_Reference_To (Def_Id, Loc),
Expression => Node);
Insert_Action (N, Temp_Decl);
Build_Allocate_Deallocate_Proc (Temp_Decl, True);
end if;
-- Generate an additional object containing the address of the
-- returned object. The type of this second object declaration
-- is the correct type required for the common processing that
-- is still performed by this subprogram. The displacement of
-- this pointer to reference the component associated with the
-- interface type will be done at the end of common processing.
New_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Make_Temporary (Loc, 'P'),
Object_Definition => New_Reference_To (PtrT, Loc),
Expression =>
Unchecked_Convert_To (PtrT,
New_Reference_To (Temp, Loc)));
Insert_Action (N, New_Decl);
Temp_Decl := New_Decl;
Temp := Defining_Identifier (New_Decl);
end;
end if;
Apply_Accessibility_Check (Temp);
-- Generate the tag assignment
-- Suppress the tag assignment when VM_Target because VM tags are
-- represented implicitly in objects.
if not Tagged_Type_Expansion then
null;
-- Ada 2005 (AI-251): Suppress the tag assignment with class-wide
-- interface objects because in this case the tag does not change.
elsif Is_Interface (Directly_Designated_Type (Etype (N))) then
pragma Assert (Is_Class_Wide_Type
(Directly_Designated_Type (Etype (N))));
null;
elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then
TagT := T;
TagR := New_Reference_To (Temp, Loc);
elsif Is_Private_Type (T)
and then Is_Tagged_Type (Underlying_Type (T))
then
TagT := Underlying_Type (T);
TagR :=
Unchecked_Convert_To (Underlying_Type (T),
Make_Explicit_Dereference (Loc,
Prefix => New_Reference_To (Temp, Loc)));
end if;
if Present (TagT) then
declare
Full_T : constant Entity_Id := Underlying_Type (TagT);
begin
Tag_Assign :=
Make_Assignment_Statement (Loc,
Name =>
Make_Selected_Component (Loc,
Prefix => TagR,
Selector_Name =>
New_Reference_To (First_Tag_Component (Full_T), Loc)),
Expression =>
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To
(Elists.Node
(First_Elmt (Access_Disp_Table (Full_T))), Loc)));
end;
-- The previous assignment has to be done in any case
Set_Assignment_OK (Name (Tag_Assign));
Insert_Action (N, Tag_Assign);
end if;
if Needs_Finalization (DesigT)
and then Needs_Finalization (T)
then
-- Generate an Adjust call if the object will be moved. In Ada
-- 2005, the object may be inherently limited, in which case
-- there is no Adjust procedure, and the object is built in
-- place. In Ada 95, the object can be limited but not
-- inherently limited if this allocator came from a return
-- statement (we're allocating the result on the secondary
-- stack). In that case, the object will be moved, so we _do_
-- want to Adjust.
if not Aggr_In_Place
and then not Is_Immutably_Limited_Type (T)
then
Insert_Action (N,
Make_Adjust_Call (
Obj_Ref =>
-- An unchecked conversion is needed in the classwide
-- case because the designated type can be an ancestor
-- of the subtype mark of the allocator.
Unchecked_Convert_To (T,
Make_Explicit_Dereference (Loc,
Prefix => New_Reference_To (Temp, Loc))),
Typ => T));
end if;
-- Generate:
-- Set_Finalize_Address (<PtrT>FM, <T>FD'Unrestricted_Access);
-- Do not generate this call in the following cases:
-- * .NET/JVM - these targets do not support address arithmetic
-- and unchecked conversion, key elements of Finalize_Address.
-- * Alfa mode - the call is useless and results in unwanted
-- expansion.
-- * CodePeer mode - TSS primitive Finalize_Address is not
-- created in this mode.
if VM_Target = No_VM
and then not Alfa_Mode
and then not CodePeer_Mode
and then Present (Finalization_Master (PtrT))
and then Present (Temp_Decl)
and then Nkind (Expression (Temp_Decl)) = N_Allocator
then
Insert_Action (N,
Make_Set_Finalize_Address_Call
(Loc => Loc,
Typ => T,
Ptr_Typ => PtrT));
end if;
end if;
Rewrite (N, New_Reference_To (Temp, Loc));
Analyze_And_Resolve (N, PtrT);
-- Ada 2005 (AI-251): Displace the pointer to reference the record
-- component containing the secondary dispatch table of the interface
-- type.
if Is_Interface (Directly_Designated_Type (PtrT)) then
Displace_Allocator_Pointer (N);
end if;
elsif Aggr_In_Place then
Temp := Make_Temporary (Loc, 'P', N);
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => New_Reference_To (PtrT, Loc),
Expression =>
Make_Allocator (Loc,
Expression => New_Reference_To (Etype (Exp), Loc)));
-- Copy the Comes_From_Source flag for the allocator we just built,
-- since logically this allocator is a replacement of the original
-- allocator node. This is for proper handling of restriction
-- No_Implicit_Heap_Allocations.
Set_Comes_From_Source
(Expression (Temp_Decl), Comes_From_Source (N));
Set_No_Initialization (Expression (Temp_Decl));
Insert_Action (N, Temp_Decl);
Build_Allocate_Deallocate_Proc (Temp_Decl, True);
Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
-- Attach the object to the associated finalization master. Thisis
-- done manually on .NET/JVM since those compilers do no support
-- pools and cannot benefit from internally generated Allocate and
-- Deallocate procedures.
if VM_Target /= No_VM
and then Is_Controlled (DesigT)
and then Present (Finalization_Master (PtrT))
then
Insert_Action (N,
Make_Attach_Call
(Obj_Ref => New_Reference_To (Temp, Loc),
Ptr_Typ => PtrT));
end if;
Rewrite (N, New_Reference_To (Temp, Loc));
Analyze_And_Resolve (N, PtrT);
elsif Is_Access_Type (T)
and then Can_Never_Be_Null (T)
then
Install_Null_Excluding_Check (Exp);
elsif Is_Access_Type (DesigT)
and then Nkind (Exp) = N_Allocator
and then Nkind (Expression (Exp)) /= N_Qualified_Expression
then
-- Apply constraint to designated subtype indication
Apply_Constraint_Check (Expression (Exp),
Designated_Type (DesigT),
No_Sliding => True);
if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then
-- Propagate constraint_error to enclosing allocator
Rewrite (Exp, New_Copy (Expression (Exp)));
end if;
else
Build_Allocate_Deallocate_Proc (N, True);
-- If we have:
-- type A is access T1;
-- X : A := new T2'(...);
-- T1 and T2 can be different subtypes, and we might need to check
-- both constraints. First check against the type of the qualified
-- expression.
Apply_Constraint_Check (Exp, T, No_Sliding => True);
if Do_Range_Check (Exp) then
Set_Do_Range_Check (Exp, False);
Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
end if;
-- A check is also needed in cases where the designated subtype is
-- constrained and differs from the subtype given in the qualified
-- expression. Note that the check on the qualified expression does
-- not allow sliding, but this check does (a relaxation from Ada 83).
if Is_Constrained (DesigT)
and then not Subtypes_Statically_Match (T, DesigT)
then
Apply_Constraint_Check
(Exp, DesigT, No_Sliding => False);
if Do_Range_Check (Exp) then
Set_Do_Range_Check (Exp, False);
Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
end if;
end if;
-- For an access to unconstrained packed array, GIGI needs to see an
-- expression with a constrained subtype in order to compute the
-- proper size for the allocator.
if Is_Array_Type (T)
and then not Is_Constrained (T)
and then Is_Packed (T)
then
declare
ConstrT : constant Entity_Id := Make_Temporary (Loc, 'A');
Internal_Exp : constant Node_Id := Relocate_Node (Exp);
begin
Insert_Action (Exp,
Make_Subtype_Declaration (Loc,
Defining_Identifier => ConstrT,
Subtype_Indication =>
Make_Subtype_From_Expr (Internal_Exp, T)));
Freeze_Itype (ConstrT, Exp);
Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp));
end;
end if;
-- Ada 2005 (AI-318-02): If the initialization expression is a call
-- to a build-in-place function, then access to the allocated object
-- must be passed to the function. Currently we limit such functions
-- to those with constrained limited result subtypes, but eventually
-- we plan to expand the allowed forms of functions that are treated
-- as build-in-place.
if Ada_Version >= Ada_2005
and then Is_Build_In_Place_Function_Call (Exp)
then
Make_Build_In_Place_Call_In_Allocator (N, Exp);
end if;
end if;
exception
when RE_Not_Available =>
return;
end Expand_Allocator_Expression;
-----------------------------
-- Expand_Array_Comparison --
-----------------------------
-- Expansion is only required in the case of array types. For the unpacked
-- case, an appropriate runtime routine is called. For packed cases, and
-- also in some other cases where a runtime routine cannot be called, the
-- form of the expansion is:
-- [body for greater_nn; boolean_expression]
-- The body is built by Make_Array_Comparison_Op, and the form of the
-- Boolean expression depends on the operator involved.
procedure Expand_Array_Comparison (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Op1 : Node_Id := Left_Opnd (N);
Op2 : Node_Id := Right_Opnd (N);
Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
Ctyp : constant Entity_Id := Component_Type (Typ1);
Expr : Node_Id;
Func_Body : Node_Id;
Func_Name : Entity_Id;
Comp : RE_Id;
Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size;
-- True for byte addressable target
function Length_Less_Than_4 (Opnd : Node_Id) return Boolean;
-- Returns True if the length of the given operand is known to be less
-- than 4. Returns False if this length is known to be four or greater
-- or is not known at compile time.
------------------------
-- Length_Less_Than_4 --
------------------------
function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is
Otyp : constant Entity_Id := Etype (Opnd);
begin
if Ekind (Otyp) = E_String_Literal_Subtype then
return String_Literal_Length (Otyp) < 4;
else
declare
Ityp : constant Entity_Id := Etype (First_Index (Otyp));
Lo : constant Node_Id := Type_Low_Bound (Ityp);
Hi : constant Node_Id := Type_High_Bound (Ityp);
Lov : Uint;
Hiv : Uint;
begin
if Compile_Time_Known_Value (Lo) then
Lov := Expr_Value (Lo);
else
return False;
end if;
if Compile_Time_Known_Value (Hi) then
Hiv := Expr_Value (Hi);
else
return False;
end if;
return Hiv < Lov + 3;
end;
end if;
end Length_Less_Than_4;
-- Start of processing for Expand_Array_Comparison
begin
-- Deal first with unpacked case, where we can call a runtime routine
-- except that we avoid this for targets for which are not addressable
-- by bytes, and for the JVM/CIL, since they do not support direct
-- addressing of array components.
if not Is_Bit_Packed_Array (Typ1)
and then Byte_Addressable
and then VM_Target = No_VM
then
-- The call we generate is:
-- Compare_Array_xn[_Unaligned]
-- (left'address, right'address, left'length, right'length) <op> 0
-- x = U for unsigned, S for signed
-- n = 8,16,32,64 for component size
-- Add _Unaligned if length < 4 and component size is 8.
-- <op> is the standard comparison operator
if Component_Size (Typ1) = 8 then
if Length_Less_Than_4 (Op1)
or else
Length_Less_Than_4 (Op2)
then
if Is_Unsigned_Type (Ctyp) then
Comp := RE_Compare_Array_U8_Unaligned;
else
Comp := RE_Compare_Array_S8_Unaligned;
end if;
else
if Is_Unsigned_Type (Ctyp) then
Comp := RE_Compare_Array_U8;
else
Comp := RE_Compare_Array_S8;
end if;
end if;
elsif Component_Size (Typ1) = 16 then
if Is_Unsigned_Type (Ctyp) then
Comp := RE_Compare_Array_U16;
else
Comp := RE_Compare_Array_S16;
end if;
elsif Component_Size (Typ1) = 32 then
if Is_Unsigned_Type (Ctyp) then
Comp := RE_Compare_Array_U32;
else
Comp := RE_Compare_Array_S32;
end if;
else pragma Assert (Component_Size (Typ1) = 64);
if Is_Unsigned_Type (Ctyp) then
Comp := RE_Compare_Array_U64;
else
Comp := RE_Compare_Array_S64;
end if;
end if;
Remove_Side_Effects (Op1, Name_Req => True);
Remove_Side_Effects (Op2, Name_Req => True);
Rewrite (Op1,
Make_Function_Call (Sloc (Op1),
Name => New_Occurrence_Of (RTE (Comp), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Op1),
Attribute_Name => Name_Address),
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Op2),
Attribute_Name => Name_Address),
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Op1),
Attribute_Name => Name_Length),
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Op2),
Attribute_Name => Name_Length))));
Rewrite (Op2,
Make_Integer_Literal (Sloc (Op2),
Intval => Uint_0));
Analyze_And_Resolve (Op1, Standard_Integer);
Analyze_And_Resolve (Op2, Standard_Integer);
return;
end if;
-- Cases where we cannot make runtime call
-- For (a <= b) we convert to not (a > b)
if Chars (N) = Name_Op_Le then
Rewrite (N,
Make_Op_Not (Loc,
Right_Opnd =>
Make_Op_Gt (Loc,
Left_Opnd => Op1,
Right_Opnd => Op2)));
Analyze_And_Resolve (N, Standard_Boolean);
return;
-- For < the Boolean expression is
-- greater__nn (op2, op1)
elsif Chars (N) = Name_Op_Lt then
Func_Body := Make_Array_Comparison_Op (Typ1, N);
-- Switch operands
Op1 := Right_Opnd (N);
Op2 := Left_Opnd (N);
-- For (a >= b) we convert to not (a < b)
elsif Chars (N) = Name_Op_Ge then
Rewrite (N,
Make_Op_Not (Loc,
Right_Opnd =>
Make_Op_Lt (Loc,
Left_Opnd => Op1,
Right_Opnd => Op2)));
Analyze_And_Resolve (N, Standard_Boolean);
return;
-- For > the Boolean expression is
-- greater__nn (op1, op2)
else
pragma Assert (Chars (N) = Name_Op_Gt);
Func_Body := Make_Array_Comparison_Op (Typ1, N);
end if;
Func_Name := Defining_Unit_Name (Specification (Func_Body));
Expr :=
Make_Function_Call (Loc,
Name => New_Reference_To (Func_Name, Loc),
Parameter_Associations => New_List (Op1, Op2));
Insert_Action (N, Func_Body);
Rewrite (N, Expr);
Analyze_And_Resolve (N, Standard_Boolean);
exception
when RE_Not_Available =>
return;
end Expand_Array_Comparison;
---------------------------
-- Expand_Array_Equality --
---------------------------
-- Expand an equality function for multi-dimensional arrays. Here is an
-- example of such a function for Nb_Dimension = 2
-- function Enn (A : atyp; B : btyp) return boolean is
-- begin
-- if (A'length (1) = 0 or else A'length (2) = 0)
-- and then
-- (B'length (1) = 0 or else B'length (2) = 0)
-- then
-- return True; -- RM 4.5.2(22)
-- end if;
-- if A'length (1) /= B'length (1)
-- or else
-- A'length (2) /= B'length (2)
-- then
-- return False; -- RM 4.5.2(23)
-- end if;
-- declare
-- A1 : Index_T1 := A'first (1);
-- B1 : Index_T1 := B'first (1);
-- begin
-- loop
-- declare
-- A2 : Index_T2 := A'first (2);
-- B2 : Index_T2 := B'first (2);
-- begin
-- loop
-- if A (A1, A2) /= B (B1, B2) then
-- return False;
-- end if;
-- exit when A2 = A'last (2);
-- A2 := Index_T2'succ (A2);
-- B2 := Index_T2'succ (B2);
-- end loop;
-- end;
-- exit when A1 = A'last (1);
-- A1 := Index_T1'succ (A1);
-- B1 := Index_T1'succ (B1);
-- end loop;
-- end;
-- return true;
-- end Enn;
-- Note on the formal types used (atyp and btyp). If either of the arrays
-- is of a private type, we use the underlying type, and do an unchecked
-- conversion of the actual. If either of the arrays has a bound depending
-- on a discriminant, then we use the base type since otherwise we have an
-- escaped discriminant in the function.
-- If both arrays are constrained and have the same bounds, we can generate
-- a loop with an explicit iteration scheme using a 'Range attribute over
-- the first array.
function Expand_Array_Equality
(Nod : Node_Id;
Lhs : Node_Id;
Rhs : Node_Id;
Bodies : List_Id;
Typ : Entity_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Nod);
Decls : constant List_Id := New_List;
Index_List1 : constant List_Id := New_List;
Index_List2 : constant List_Id := New_List;
Actuals : List_Id;
Formals : List_Id;
Func_Name : Entity_Id;
Func_Body : Node_Id;
A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
Ltyp : Entity_Id;
Rtyp : Entity_Id;
-- The parameter types to be used for the formals
function Arr_Attr
(Arr : Entity_Id;
Nam : Name_Id;
Num : Int) return Node_Id;
-- This builds the attribute reference Arr'Nam (Expr)
function Component_Equality (Typ : Entity_Id) return Node_Id;
-- Create one statement to compare corresponding components, designated
-- by a full set of indexes.
function Get_Arg_Type (N : Node_Id) return Entity_Id;
-- Given one of the arguments, computes the appropriate type to be used
-- for that argument in the corresponding function formal
function Handle_One_Dimension
(N : Int;
Index : Node_Id) return Node_Id;
-- This procedure returns the following code
--
-- declare
-- Bn : Index_T := B'First (N);
-- begin
-- loop
-- xxx
-- exit when An = A'Last (N);
-- An := Index_T'Succ (An)
-- Bn := Index_T'Succ (Bn)
-- end loop;
-- end;
--
-- If both indexes are constrained and identical, the procedure
-- returns a simpler loop:
--
-- for An in A'Range (N) loop
-- xxx
-- end loop
--
-- N is the dimension for which we are generating a loop. Index is the
-- N'th index node, whose Etype is Index_Type_n in the above code. The
-- xxx statement is either the loop or declare for the next dimension
-- or if this is the last dimension the comparison of corresponding
-- components of the arrays.
--
-- The actual way the code works is to return the comparison of
-- corresponding components for the N+1 call. That's neater!
function Test_Empty_Arrays return Node_Id;
-- This function constructs the test for both arrays being empty
-- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
-- and then
-- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
function Test_Lengths_Correspond return Node_Id;
-- This function constructs the test for arrays having different lengths
-- in at least one index position, in which case the resulting code is:
-- A'length (1) /= B'length (1)
-- or else
-- A'length (2) /= B'length (2)
-- or else
-- ...
--------------
-- Arr_Attr --
--------------
function Arr_Attr
(Arr : Entity_Id;
Nam : Name_Id;
Num : Int) return Node_Id
is
begin
return
Make_Attribute_Reference (Loc,
Attribute_Name => Nam,
Prefix => New_Reference_To (Arr, Loc),
Expressions => New_List (Make_Integer_Literal (Loc, Num)));
end Arr_Attr;
------------------------
-- Component_Equality --
------------------------
function Component_Equality (Typ : Entity_Id) return Node_Id is
Test : Node_Id;
L, R : Node_Id;
begin
-- if a(i1...) /= b(j1...) then return false; end if;
L :=
Make_Indexed_Component (Loc,
Prefix => Make_Identifier (Loc, Chars (A)),
Expressions => Index_List1);
R :=
Make_Indexed_Component (Loc,
Prefix => Make_Identifier (Loc, Chars (B)),
Expressions => Index_List2);
Test := Expand_Composite_Equality
(Nod, Component_Type (Typ), L, R, Decls);
-- If some (sub)component is an unchecked_union, the whole operation
-- will raise program error.
if Nkind (Test) = N_Raise_Program_Error then
-- This node is going to be inserted at a location where a
-- statement is expected: clear its Etype so analysis will set
-- it to the expected Standard_Void_Type.
Set_Etype (Test, Empty);
return Test;
else
return
Make_Implicit_If_Statement (Nod,
Condition => Make_Op_Not (Loc, Right_Opnd => Test),
Then_Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression => New_Occurrence_Of (Standard_False, Loc))));
end if;
end Component_Equality;
------------------
-- Get_Arg_Type --
------------------
function Get_Arg_Type (N : Node_Id) return Entity_Id is
T : Entity_Id;
X : Node_Id;
begin
T := Etype (N);
if No (T) then
return Typ;
else
T := Underlying_Type (T);
X := First_Index (T);
while Present (X) loop
if Denotes_Discriminant (Type_Low_Bound (Etype (X)))
or else
Denotes_Discriminant (Type_High_Bound (Etype (X)))
then
T := Base_Type (T);
exit;
end if;
Next_Index (X);
end loop;
return T;
end if;
end Get_Arg_Type;
--------------------------
-- Handle_One_Dimension --
---------------------------
function Handle_One_Dimension
(N : Int;
Index : Node_Id) return Node_Id
is
Need_Separate_Indexes : constant Boolean :=
Ltyp /= Rtyp
or else not Is_Constrained (Ltyp);
-- If the index types are identical, and we are working with
-- constrained types, then we can use the same index for both
-- of the arrays.
An : constant Entity_Id := Make_Temporary (Loc, 'A');
Bn : Entity_Id;
Index_T : Entity_Id;
Stm_List : List_Id;
Loop_Stm : Node_Id;
begin
if N > Number_Dimensions (Ltyp) then
return Component_Equality (Ltyp);
end if;
-- Case where we generate a loop
Index_T := Base_Type (Etype (Index));
if Need_Separate_Indexes then
Bn := Make_Temporary (Loc, 'B');
else
Bn := An;
end if;
Append (New_Reference_To (An, Loc), Index_List1);
Append (New_Reference_To (Bn, Loc), Index_List2);
Stm_List := New_List (
Handle_One_Dimension (N + 1, Next_Index (Index)));
if Need_Separate_Indexes then
-- Generate guard for loop, followed by increments of indexes
Append_To (Stm_List,
Make_Exit_Statement (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd => New_Reference_To (An, Loc),
Right_Opnd => Arr_Attr (A, Name_Last, N))));
Append_To (Stm_List,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (An, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Index_T, Loc),
Attribute_Name => Name_Succ,
Expressions => New_List (New_Reference_To (An, Loc)))));
Append_To (Stm_List,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Bn, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Index_T, Loc),
Attribute_Name => Name_Succ,
Expressions => New_List (New_Reference_To (Bn, Loc)))));
end if;
-- If separate indexes, we need a declare block for An and Bn, and a
-- loop without an iteration scheme.
if Need_Separate_Indexes then
Loop_Stm :=
Make_Implicit_Loop_Statement (Nod, Statements => Stm_List);
return
Make_Block_Statement (Loc,
Declarations => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => An,
Object_Definition => New_Reference_To (Index_T, Loc),
Expression => Arr_Attr (A, Name_First, N)),
Make_Object_Declaration (Loc,
Defining_Identifier => Bn,
Object_Definition => New_Reference_To (Index_T, Loc),
Expression => Arr_Attr (B, Name_First, N))),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Loop_Stm)));
-- If no separate indexes, return loop statement with explicit
-- iteration scheme on its own
else
Loop_Stm :=
Make_Implicit_Loop_Statement (Nod,
Statements => Stm_List,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => An,
Discrete_Subtype_Definition =>
Arr_Attr (A, Name_Range, N))));
return Loop_Stm;
end if;
end Handle_One_Dimension;
-----------------------
-- Test_Empty_Arrays --
-----------------------
function Test_Empty_Arrays return Node_Id is
Alist : Node_Id;
Blist : Node_Id;
Atest : Node_Id;
Btest : Node_Id;
begin
Alist := Empty;
Blist := Empty;
for J in 1 .. Number_Dimensions (Ltyp) loop
Atest :=
Make_Op_Eq (Loc,
Left_Opnd => Arr_Attr (A, Name_Length, J),
Right_Opnd => Make_Integer_Literal (Loc, 0));
Btest :=
Make_Op_Eq (Loc,
Left_Opnd => Arr_Attr (B, Name_Length, J),
Right_Opnd => Make_Integer_Literal (Loc, 0));
if No (Alist) then
Alist := Atest;
Blist := Btest;
else
Alist :=
Make_Or_Else (Loc,
Left_Opnd => Relocate_Node (Alist),
Right_Opnd => Atest);
Blist :=
Make_Or_Else (Loc,
Left_Opnd => Relocate_Node (Blist),
Right_Opnd => Btest);
end if;
end loop;
return
Make_And_Then (Loc,
Left_Opnd => Alist,
Right_Opnd => Blist);
end Test_Empty_Arrays;
-----------------------------
-- Test_Lengths_Correspond --
-----------------------------
function Test_Lengths_Correspond return Node_Id is
Result : Node_Id;
Rtest : Node_Id;
begin
Result := Empty;
for J in 1 .. Number_Dimensions (Ltyp) loop
Rtest :=
Make_Op_Ne (Loc,
Left_Opnd => Arr_Attr (A, Name_Length, J),
Right_Opnd => Arr_Attr (B, Name_Length, J));
if No (Result) then
Result := Rtest;
else
Result :=
Make_Or_Else (Loc,
Left_Opnd => Relocate_Node (Result),
Right_Opnd => Rtest);
end if;
end loop;
return Result;
end Test_Lengths_Correspond;
-- Start of processing for Expand_Array_Equality
begin
Ltyp := Get_Arg_Type (Lhs);
Rtyp := Get_Arg_Type (Rhs);
-- For now, if the argument types are not the same, go to the base type,
-- since the code assumes that the formals have the same type. This is
-- fixable in future ???
if Ltyp /= Rtyp then
Ltyp := Base_Type (Ltyp);
Rtyp := Base_Type (Rtyp);
pragma Assert (Ltyp = Rtyp);
end if;
-- Build list of formals for function
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => A,
Parameter_Type => New_Reference_To (Ltyp, Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => B,
Parameter_Type => New_Reference_To (Rtyp, Loc)));
Func_Name := Make_Temporary (Loc, 'E');
-- Build statement sequence for function
Func_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Func_Name,
Parameter_Specifications => Formals,
Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Implicit_If_Statement (Nod,
Condition => Test_Empty_Arrays,
Then_Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression =>
New_Occurrence_Of (Standard_True, Loc)))),
Make_Implicit_If_Statement (Nod,
Condition => Test_Lengths_Correspond,
Then_Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression =>
New_Occurrence_Of (Standard_False, Loc)))),
Handle_One_Dimension (1, First_Index (Ltyp)),
Make_Simple_Return_Statement (Loc,
Expression => New_Occurrence_Of (Standard_True, Loc)))));
Set_Has_Completion (Func_Name, True);
Set_Is_Inlined (Func_Name);
-- If the array type is distinct from the type of the arguments, it
-- is the full view of a private type. Apply an unchecked conversion
-- to insure that analysis of the call succeeds.
declare
L, R : Node_Id;
begin
L := Lhs;
R := Rhs;
if No (Etype (Lhs))
or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp)
then
L := OK_Convert_To (Ltyp, Lhs);
end if;
if No (Etype (Rhs))
or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp)
then
R := OK_Convert_To (Rtyp, Rhs);
end if;
Actuals := New_List (L, R);
end;
Append_To (Bodies, Func_Body);
return
Make_Function_Call (Loc,
Name => New_Reference_To (Func_Name, Loc),
Parameter_Associations => Actuals);
end Expand_Array_Equality;
-----------------------------
-- Expand_Boolean_Operator --
-----------------------------
-- Note that we first get the actual subtypes of the operands, since we
-- always want to deal with types that have bounds.
procedure Expand_Boolean_Operator (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
begin
-- Special case of bit packed array where both operands are known to be
-- properly aligned. In this case we use an efficient run time routine
-- to carry out the operation (see System.Bit_Ops).
if Is_Bit_Packed_Array (Typ)
and then not Is_Possibly_Unaligned_Object (Left_Opnd (N))
and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
then
Expand_Packed_Boolean_Operator (N);
return;
end if;
-- For the normal non-packed case, the general expansion is to build
-- function for carrying out the comparison (use Make_Boolean_Array_Op)
-- and then inserting it into the tree. The original operator node is
-- then rewritten as a call to this function. We also use this in the
-- packed case if either operand is a possibly unaligned object.
declare
Loc : constant Source_Ptr := Sloc (N);
L : constant Node_Id := Relocate_Node (Left_Opnd (N));
R : constant Node_Id := Relocate_Node (Right_Opnd (N));
Func_Body : Node_Id;
Func_Name : Entity_Id;
begin
Convert_To_Actual_Subtype (L);
Convert_To_Actual_Subtype (R);
Ensure_Defined (Etype (L), N);
Ensure_Defined (Etype (R), N);
Apply_Length_Check (R, Etype (L));
if Nkind (N) = N_Op_Xor then
Silly_Boolean_Array_Xor_Test (N, Etype (L));
end if;
if Nkind (Parent (N)) = N_Assignment_Statement
and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
then
Build_Boolean_Array_Proc_Call (Parent (N), L, R);
elsif Nkind (Parent (N)) = N_Op_Not
and then Nkind (N) = N_Op_And
and then
Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
then
return;
else
Func_Body := Make_Boolean_Array_Op (Etype (L), N);
Func_Name := Defining_Unit_Name (Specification (Func_Body));
Insert_Action (N, Func_Body);
-- Now rewrite the expression with a call
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (Func_Name, Loc),
Parameter_Associations =>
New_List (
L,
Make_Type_Conversion
(Loc, New_Reference_To (Etype (L), Loc), R))));
Analyze_And_Resolve (N, Typ);
end if;
end;
end Expand_Boolean_Operator;
------------------------------------------------
-- Expand_Compare_Minimize_Eliminate_Overflow --
------------------------------------------------
procedure Expand_Compare_Minimize_Eliminate_Overflow (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Result_Type : constant Entity_Id := Etype (N);
-- Capture result type (could be a derived boolean type)
Llo, Lhi : Uint;
Rlo, Rhi : Uint;
LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer);
-- Entity for Long_Long_Integer'Base
Check : constant Overflow_Mode_Type := Overflow_Check_Mode;
-- Current overflow checking mode
procedure Set_True;
procedure Set_False;
-- These procedures rewrite N with an occurrence of Standard_True or
-- Standard_False, and then makes a call to Warn_On_Known_Condition.
---------------
-- Set_False --
---------------
procedure Set_False is
begin
Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
Warn_On_Known_Condition (N);
end Set_False;
--------------
-- Set_True --
--------------
procedure Set_True is
begin
Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
Warn_On_Known_Condition (N);
end Set_True;
-- Start of processing for Expand_Compare_Minimize_Eliminate_Overflow
begin
-- Nothing to do unless we have a comparison operator with operands
-- that are signed integer types, and we are operating in either
-- MINIMIZED or ELIMINATED overflow checking mode.
if Nkind (N) not in N_Op_Compare
or else Check not in Minimized_Or_Eliminated
or else not Is_Signed_Integer_Type (Etype (Left_Opnd (N)))
then
return;
end if;
-- OK, this is the case we are interested in. First step is to process
-- our operands using the Minimize_Eliminate circuitry which applies
-- this processing to the two operand subtrees.
Minimize_Eliminate_Overflows
(Left_Opnd (N), Llo, Lhi, Top_Level => False);
Minimize_Eliminate_Overflows
(Right_Opnd (N), Rlo, Rhi, Top_Level => False);
-- See if the range information decides the result of the comparison.
-- We can only do this if we in fact have full range information (which
-- won't be the case if either operand is bignum at this stage).
if Llo /= No_Uint and then Rlo /= No_Uint then
case N_Op_Compare (Nkind (N)) is
when N_Op_Eq =>
if Llo = Lhi and then Rlo = Rhi and then Llo = Rlo then
Set_True;
elsif Llo > Rhi or else Lhi < Rlo then
Set_False;
end if;
when N_Op_Ge =>
if Llo >= Rhi then
Set_True;
elsif Lhi < Rlo then
Set_False;
end if;
when N_Op_Gt =>
if Llo > Rhi then
Set_True;
elsif Lhi <= Rlo then
Set_False;
end if;
when N_Op_Le =>
if Llo > Rhi then
Set_False;
elsif Lhi <= Rlo then
Set_True;
end if;
when N_Op_Lt =>
if Llo >= Rhi then
Set_False;
elsif Lhi < Rlo then
Set_True;
end if;
when N_Op_Ne =>
if Llo = Lhi and then Rlo = Rhi and then Llo = Rlo then
Set_False;
elsif Llo > Rhi or else Lhi < Rlo then
Set_True;
end if;
end case;
-- All done if we did the rewrite
if Nkind (N) not in N_Op_Compare then
return;
end if;
end if;
-- Otherwise, time to do the comparison
declare
Ltype : constant Entity_Id := Etype (Left_Opnd (N));
Rtype : constant Entity_Id := Etype (Right_Opnd (N));
begin
-- If the two operands have the same signed integer type we are
-- all set, nothing more to do. This is the case where either
-- both operands were unchanged, or we rewrote both of them to
-- be Long_Long_Integer.
-- Note: Entity for the comparison may be wrong, but it's not worth
-- the effort to change it, since the back end does not use it.
if Is_Signed_Integer_Type (Ltype)
and then Base_Type (Ltype) = Base_Type (Rtype)
then
return;
-- Here if bignums are involved (can only happen in ELIMINATED mode)
elsif Is_RTE (Ltype, RE_Bignum) or else Is_RTE (Rtype, RE_Bignum) then
declare
Left : Node_Id := Left_Opnd (N);
Right : Node_Id := Right_Opnd (N);
-- Bignum references for left and right operands
begin
if not Is_RTE (Ltype, RE_Bignum) then
Left := Convert_To_Bignum (Left);
elsif not Is_RTE (Rtype, RE_Bignum) then
Right := Convert_To_Bignum (Right);
end if;
-- We rewrite our node with:
-- do
-- Bnn : Result_Type;
-- declare
-- M : Mark_Id := SS_Mark;
-- begin
-- Bnn := Big_xx (Left, Right); (xx = EQ, NT etc)
-- SS_Release (M);
-- end;
-- in
-- Bnn
-- end
declare
Blk : constant Node_Id := Make_Bignum_Block (Loc);
Bnn : constant Entity_Id := Make_Temporary (Loc, 'B', N);
Ent : RE_Id;
begin
case N_Op_Compare (Nkind (N)) is
when N_Op_Eq => Ent := RE_Big_EQ;
when N_Op_Ge => Ent := RE_Big_GE;
when N_Op_Gt => Ent := RE_Big_GT;
when N_Op_Le => Ent := RE_Big_LE;
when N_Op_Lt => Ent := RE_Big_LT;
when N_Op_Ne => Ent := RE_Big_NE;
end case;
-- Insert assignment to Bnn into the bignum block
Insert_Before
(First (Statements (Handled_Statement_Sequence (Blk))),
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Bnn, Loc),
Expression =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (Ent), Loc),
Parameter_Associations => New_List (Left, Right))));
-- Now do the rewrite with expression actions
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => Bnn,
Object_Definition =>
New_Occurrence_Of (Result_Type, Loc)),
Blk),
Expression => New_Occurrence_Of (Bnn, Loc)));
Analyze_And_Resolve (N, Result_Type);
end;
end;
-- No bignums involved, but types are different, so we must have
-- rewritten one of the operands as a Long_Long_Integer but not
-- the other one.
-- If left operand is Long_Long_Integer, convert right operand
-- and we are done (with a comparison of two Long_Long_Integers).
elsif Ltype = LLIB then
Convert_To_And_Rewrite (LLIB, Right_Opnd (N));
Analyze_And_Resolve (Right_Opnd (N), LLIB, Suppress => All_Checks);
return;
-- If right operand is Long_Long_Integer, convert left operand
-- and we are done (with a comparison of two Long_Long_Integers).
-- This is the only remaining possibility
else pragma Assert (Rtype = LLIB);
Convert_To_And_Rewrite (LLIB, Left_Opnd (N));
Analyze_And_Resolve (Left_Opnd (N), LLIB, Suppress => All_Checks);
return;
end if;
end;
end Expand_Compare_Minimize_Eliminate_Overflow;
-------------------------------
-- Expand_Composite_Equality --
-------------------------------
-- This function is only called for comparing internal fields of composite
-- types when these fields are themselves composites. This is a special
-- case because it is not possible to respect normal Ada visibility rules.
function Expand_Composite_Equality
(Nod : Node_Id;
Typ : Entity_Id;
Lhs : Node_Id;
Rhs : Node_Id;
Bodies : List_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Nod);
Full_Type : Entity_Id;
Prim : Elmt_Id;
Eq_Op : Entity_Id;
function Find_Primitive_Eq return Node_Id;
-- AI05-0123: Locate primitive equality for type if it exists, and
-- build the corresponding call. If operation is abstract, replace
-- call with an explicit raise. Return Empty if there is no primitive.
-----------------------
-- Find_Primitive_Eq --
-----------------------
function Find_Primitive_Eq return Node_Id is
Prim_E : Elmt_Id;
Prim : Node_Id;
begin
Prim_E := First_Elmt (Collect_Primitive_Operations (Typ));
while Present (Prim_E) loop
Prim := Node (Prim_E);
-- Locate primitive equality with the right signature
if Chars (Prim) = Name_Op_Eq
and then Etype (First_Formal (Prim)) =
Etype (Next_Formal (First_Formal (Prim)))
and then Etype (Prim) = Standard_Boolean
then
if Is_Abstract_Subprogram (Prim) then
return
Make_Raise_Program_Error (Loc,
Reason => PE_Explicit_Raise);
else
return
Make_Function_Call (Loc,
Name => New_Reference_To (Prim, Loc),
Parameter_Associations => New_List (Lhs, Rhs));
end if;
end if;
Next_Elmt (Prim_E);
end loop;
-- If not found, predefined operation will be used
return Empty;
end Find_Primitive_Eq;
-- Start of processing for Expand_Composite_Equality
begin
if Is_Private_Type (Typ) then
Full_Type := Underlying_Type (Typ);
else
Full_Type := Typ;
end if;
-- Defense against malformed private types with no completion the error
-- will be diagnosed later by check_completion
if No (Full_Type) then
return New_Reference_To (Standard_False, Loc);
end if;
Full_Type := Base_Type (Full_Type);
if Is_Array_Type (Full_Type) then
-- If the operand is an elementary type other than a floating-point
-- type, then we can simply use the built-in block bitwise equality,
-- since the predefined equality operators always apply and bitwise
-- equality is fine for all these cases.
if Is_Elementary_Type (Component_Type (Full_Type))
and then not Is_Floating_Point_Type (Component_Type (Full_Type))
then
return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
-- For composite component types, and floating-point types, use the
-- expansion. This deals with tagged component types (where we use
-- the applicable equality routine) and floating-point, (where we
-- need to worry about negative zeroes), and also the case of any
-- composite type recursively containing such fields.
else
return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type);
end if;
elsif Is_Tagged_Type (Full_Type) then
-- Call the primitive operation "=" of this type
if Is_Class_Wide_Type (Full_Type) then
Full_Type := Root_Type (Full_Type);
end if;
-- If this is derived from an untagged private type completed with a
-- tagged type, it does not have a full view, so we use the primitive
-- operations of the private type. This check should no longer be
-- necessary when these types receive their full views ???
if Is_Private_Type (Typ)
and then not Is_Tagged_Type (Typ)
and then not Is_Controlled (Typ)
and then Is_Derived_Type (Typ)
and then No (Full_View (Typ))
then
Prim := First_Elmt (Collect_Primitive_Operations (Typ));
else
Prim := First_Elmt (Primitive_Operations (Full_Type));
end if;
loop
Eq_Op := Node (Prim);
exit when Chars (Eq_Op) = Name_Op_Eq
and then Etype (First_Formal (Eq_Op)) =
Etype (Next_Formal (First_Formal (Eq_Op)))
and then Base_Type (Etype (Eq_Op)) = Standard_Boolean;
Next_Elmt (Prim);
pragma Assert (Present (Prim));
end loop;
Eq_Op := Node (Prim);
return
Make_Function_Call (Loc,
Name => New_Reference_To (Eq_Op, Loc),
Parameter_Associations =>
New_List
(Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs),
Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs)));
elsif Is_Record_Type (Full_Type) then
Eq_Op := TSS (Full_Type, TSS_Composite_Equality);
if Present (Eq_Op) then
if Etype (First_Formal (Eq_Op)) /= Full_Type then
-- Inherited equality from parent type. Convert the actuals to
-- match signature of operation.
declare
T : constant Entity_Id := Etype (First_Formal (Eq_Op));
begin
return
Make_Function_Call (Loc,
Name => New_Reference_To (Eq_Op, Loc),
Parameter_Associations => New_List (
OK_Convert_To (T, Lhs),
OK_Convert_To (T, Rhs)));
end;
else
-- Comparison between Unchecked_Union components
if Is_Unchecked_Union (Full_Type) then
declare
Lhs_Type : Node_Id := Full_Type;
Rhs_Type : Node_Id := Full_Type;
Lhs_Discr_Val : Node_Id;
Rhs_Discr_Val : Node_Id;
begin
-- Lhs subtype
if Nkind (Lhs) = N_Selected_Component then
Lhs_Type := Etype (Entity (Selector_Name (Lhs)));
end if;
-- Rhs subtype
if Nkind (Rhs) = N_Selected_Component then
Rhs_Type := Etype (Entity (Selector_Name (Rhs)));
end if;
-- Lhs of the composite equality
if Is_Constrained (Lhs_Type) then
-- Since the enclosing record type can never be an
-- Unchecked_Union (this code is executed for records
-- that do not have variants), we may reference its
-- discriminant(s).
if Nkind (Lhs) = N_Selected_Component
and then Has_Per_Object_Constraint (
Entity (Selector_Name (Lhs)))
then
Lhs_Discr_Val :=
Make_Selected_Component (Loc,
Prefix => Prefix (Lhs),
Selector_Name =>
New_Copy
(Get_Discriminant_Value
(First_Discriminant (Lhs_Type),
Lhs_Type,
Stored_Constraint (Lhs_Type))));
else
Lhs_Discr_Val :=
New_Copy
(Get_Discriminant_Value
(First_Discriminant (Lhs_Type),
Lhs_Type,
Stored_Constraint (Lhs_Type)));
end if;
else
-- It is not possible to infer the discriminant since
-- the subtype is not constrained.
return
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction);
end if;
-- Rhs of the composite equality
if Is_Constrained (Rhs_Type) then
if Nkind (Rhs) = N_Selected_Component
and then Has_Per_Object_Constraint
(Entity (Selector_Name (Rhs)))
then
Rhs_Discr_Val :=
Make_Selected_Component (Loc,
Prefix => Prefix (Rhs),
Selector_Name =>
New_Copy
(Get_Discriminant_Value
(First_Discriminant (Rhs_Type),
Rhs_Type,
Stored_Constraint (Rhs_Type))));
else
Rhs_Discr_Val :=
New_Copy
(Get_Discriminant_Value
(First_Discriminant (Rhs_Type),
Rhs_Type,
Stored_Constraint (Rhs_Type)));
end if;
else
return
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction);
end if;
-- Call the TSS equality function with the inferred
-- discriminant values.
return
Make_Function_Call (Loc,
Name => New_Reference_To (Eq_Op, Loc),
Parameter_Associations => New_List (
Lhs,
Rhs,
Lhs_Discr_Val,
Rhs_Discr_Val));
end;
else
return
Make_Function_Call (Loc,
Name => New_Reference_To (Eq_Op, Loc),
Parameter_Associations => New_List (Lhs, Rhs));
end if;
end if;
-- Equality composes in Ada 2012 for untagged record types. It also
-- composes for bounded strings, because they are part of the
-- predefined environment. We could make it compose for bounded
-- strings by making them tagged, or by making sure all subcomponents
-- are set to the same value, even when not used. Instead, we have
-- this special case in the compiler, because it's more efficient.
elsif Ada_Version >= Ada_2012 or else Is_Bounded_String (Typ) then
-- if no TSS has been created for the type, check whether there is
-- a primitive equality declared for it.
declare
Op : constant Node_Id := Find_Primitive_Eq;
begin
-- Use user-defined primitive if it exists, otherwise use
-- predefined equality.
if Present (Op) then
return Op;
else
return Make_Op_Eq (Loc, Lhs, Rhs);
end if;
end;
else
return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies);
end if;
else
-- If not array or record type, it is predefined equality.
return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
end if;
end Expand_Composite_Equality;
------------------------
-- Expand_Concatenate --
------------------------
procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id) is
Loc : constant Source_Ptr := Sloc (Cnode);
Atyp : constant Entity_Id := Base_Type (Etype (Cnode));
-- Result type of concatenation
Ctyp : constant Entity_Id := Base_Type (Component_Type (Etype (Cnode)));
-- Component type. Elements of this component type can appear as one
-- of the operands of concatenation as well as arrays.
Istyp : constant Entity_Id := Etype (First_Index (Atyp));
-- Index subtype
Ityp : constant Entity_Id := Base_Type (Istyp);
-- Index type. This is the base type of the index subtype, and is used
-- for all computed bounds (which may be out of range of Istyp in the
-- case of null ranges).
Artyp : Entity_Id;
-- This is the type we use to do arithmetic to compute the bounds and
-- lengths of operands. The choice of this type is a little subtle and
-- is discussed in a separate section at the start of the body code.
Concatenation_Error : exception;
-- Raised if concatenation is sure to raise a CE
Result_May_Be_Null : Boolean := True;
-- Reset to False if at least one operand is encountered which is known
-- at compile time to be non-null. Used for handling the special case
-- of setting the high bound to the last operand high bound for a null
-- result, thus ensuring a proper high bound in the super-flat case.
N : constant Nat := List_Length (Opnds);
-- Number of concatenation operands including possibly null operands
NN : Nat := 0;
-- Number of operands excluding any known to be null, except that the
-- last operand is always retained, in case it provides the bounds for
-- a null result.
Opnd : Node_Id;
-- Current operand being processed in the loop through operands. After
-- this loop is complete, always contains the last operand (which is not
-- the same as Operands (NN), since null operands are skipped).
-- Arrays describing the operands, only the first NN entries of each
-- array are set (NN < N when we exclude known null operands).
Is_Fixed_Length : array (1 .. N) of Boolean;
-- True if length of corresponding operand known at compile time
Operands : array (1 .. N) of Node_Id;
-- Set to the corresponding entry in the Opnds list (but note that null
-- operands are excluded, so not all entries in the list are stored).
Fixed_Length : array (1 .. N) of Uint;
-- Set to length of operand. Entries in this array are set only if the
-- corresponding entry in Is_Fixed_Length is True.
Opnd_Low_Bound : array (1 .. N) of Node_Id;
-- Set to lower bound of operand. Either an integer literal in the case
-- where the bound is known at compile time, else actual lower bound.
-- The operand low bound is of type Ityp.
Var_Length : array (1 .. N) of Entity_Id;
-- Set to an entity of type Natural that contains the length of an
-- operand whose length is not known at compile time. Entries in this
-- array are set only if the corresponding entry in Is_Fixed_Length
-- is False. The entity is of type Artyp.
Aggr_Length : array (0 .. N) of Node_Id;
-- The J'th entry in an expression node that represents the total length
-- of operands 1 through J. It is either an integer literal node, or a
-- reference to a constant entity with the right value, so it is fine
-- to just do a Copy_Node to get an appropriate copy. The extra zero'th
-- entry always is set to zero. The length is of type Artyp.
Low_Bound : Node_Id;
-- A tree node representing the low bound of the result (of type Ityp).
-- This is either an integer literal node, or an identifier reference to
-- a constant entity initialized to the appropriate value.
Last_Opnd_Low_Bound : Node_Id;
-- A tree node representing the low bound of the last operand. This
-- need only be set if the result could be null. It is used for the
-- special case of setting the right low bound for a null result.
-- This is of type Ityp.
Last_Opnd_High_Bound : Node_Id;
-- A tree node representing the high bound of the last operand. This
-- need only be set if the result could be null. It is used for the
-- special case of setting the right high bound for a null result.
-- This is of type Ityp.
High_Bound : Node_Id;
-- A tree node representing the high bound of the result (of type Ityp)
Result : Node_Id;
-- Result of the concatenation (of type Ityp)
Actions : constant List_Id := New_List;
-- Collect actions to be inserted
Known_Non_Null_Operand_Seen : Boolean;
-- Set True during generation of the assignments of operands into
-- result once an operand known to be non-null has been seen.
function Make_Artyp_Literal (Val : Nat) return Node_Id;
-- This function makes an N_Integer_Literal node that is returned in
-- analyzed form with the type set to Artyp. Importantly this literal
-- is not flagged as static, so that if we do computations with it that
-- result in statically detected out of range conditions, we will not
-- generate error messages but instead warning messages.
function To_Artyp (X : Node_Id) return Node_Id;
-- Given a node of type Ityp, returns the corresponding value of type
-- Artyp. For non-enumeration types, this is a plain integer conversion.
-- For enum types, the Pos of the value is returned.
function To_Ityp (X : Node_Id) return Node_Id;
-- The inverse function (uses Val in the case of enumeration types)
------------------------
-- Make_Artyp_Literal --
------------------------
function Make_Artyp_Literal (Val : Nat) return Node_Id is
Result : constant Node_Id := Make_Integer_Literal (Loc, Val);
begin
Set_Etype (Result, Artyp);
Set_Analyzed (Result, True);
Set_Is_Static_Expression (Result, False);
return Result;
end Make_Artyp_Literal;
--------------
-- To_Artyp --
--------------
function To_Artyp (X : Node_Id) return Node_Id is
begin
if Ityp = Base_Type (Artyp) then
return X;
elsif Is_Enumeration_Type (Ityp) then
return
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ityp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (X));
else
return Convert_To (Artyp, X);
end if;
end To_Artyp;
-------------
-- To_Ityp --
-------------
function To_Ityp (X : Node_Id) return Node_Id is
begin
if Is_Enumeration_Type (Ityp) then
return
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ityp, Loc),
Attribute_Name => Name_Val,
Expressions => New_List (X));
-- Case where we will do a type conversion
else
if Ityp = Base_Type (Artyp) then
return X;
else
return Convert_To (Ityp, X);
end if;
end if;
end To_Ityp;
-- Local Declarations
Opnd_Typ : Entity_Id;
Ent : Entity_Id;
Len : Uint;
J : Nat;
Clen : Node_Id;
Set : Boolean;
-- Start of processing for Expand_Concatenate
begin
-- Choose an appropriate computational type
-- We will be doing calculations of lengths and bounds in this routine
-- and computing one from the other in some cases, e.g. getting the high
-- bound by adding the length-1 to the low bound.
-- We can't just use the index type, or even its base type for this
-- purpose for two reasons. First it might be an enumeration type which
-- is not suitable for computations of any kind, and second it may
-- simply not have enough range. For example if the index type is
-- -128..+127 then lengths can be up to 256, which is out of range of
-- the type.
-- For enumeration types, we can simply use Standard_Integer, this is
-- sufficient since the actual number of enumeration literals cannot
-- possibly exceed the range of integer (remember we will be doing the
-- arithmetic with POS values, not representation values).
if Is_Enumeration_Type (Ityp) then
Artyp := Standard_Integer;
-- If index type is Positive, we use the standard unsigned type, to give
-- more room on the top of the range, obviating the need for an overflow
-- check when creating the upper bound. This is needed to avoid junk
-- overflow checks in the common case of String types.
-- ??? Disabled for now
-- elsif Istyp = Standard_Positive then
-- Artyp := Standard_Unsigned;
-- For modular types, we use a 32-bit modular type for types whose size
-- is in the range 1-31 bits. For 32-bit unsigned types, we use the
-- identity type, and for larger unsigned types we use 64-bits.
elsif Is_Modular_Integer_Type (Ityp) then
if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then
Artyp := Standard_Unsigned;
elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then
Artyp := Ityp;
else
Artyp := RTE (RE_Long_Long_Unsigned);
end if;
-- Similar treatment for signed types
else
if RM_Size (Ityp) < RM_Size (Standard_Integer) then
Artyp := Standard_Integer;
elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then
Artyp := Ityp;
else
Artyp := Standard_Long_Long_Integer;
end if;
end if;
-- Supply dummy entry at start of length array
Aggr_Length (0) := Make_Artyp_Literal (0);
-- Go through operands setting up the above arrays
J := 1;
while J <= N loop
Opnd := Remove_Head (Opnds);
Opnd_Typ := Etype (Opnd);
-- The parent got messed up when we put the operands in a list,
-- so now put back the proper parent for the saved operand, that
-- is to say the concatenation node, to make sure that each operand
-- is seen as a subexpression, e.g. if actions must be inserted.
Set_Parent (Opnd, Cnode);
-- Set will be True when we have setup one entry in the array
Set := False;
-- Singleton element (or character literal) case
if Base_Type (Opnd_Typ) = Ctyp then
NN := NN + 1;
Operands (NN) := Opnd;
Is_Fixed_Length (NN) := True;
Fixed_Length (NN) := Uint_1;
Result_May_Be_Null := False;
-- Set low bound of operand (no need to set Last_Opnd_High_Bound
-- since we know that the result cannot be null).
Opnd_Low_Bound (NN) :=
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Istyp, Loc),
Attribute_Name => Name_First);
Set := True;
-- String literal case (can only occur for strings of course)
elsif Nkind (Opnd) = N_String_Literal then
Len := String_Literal_Length (Opnd_Typ);
if Len /= 0 then
Result_May_Be_Null := False;
end if;
-- Capture last operand low and high bound if result could be null
if J = N and then Result_May_Be_Null then
Last_Opnd_Low_Bound :=
New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ));
Last_Opnd_High_Bound :=
Make_Op_Subtract (Loc,
Left_Opnd =>
New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)),
Right_Opnd => Make_Integer_Literal (Loc, 1));
end if;
-- Skip null string literal
if J < N and then Len = 0 then
goto Continue;
end if;
NN := NN + 1;
Operands (NN) := Opnd;
Is_Fixed_Length (NN) := True;
-- Set length and bounds
Fixed_Length (NN) := Len;
Opnd_Low_Bound (NN) :=
New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ));
Set := True;
-- All other cases
else
-- Check constrained case with known bounds
if Is_Constrained (Opnd_Typ) then
declare
Index : constant Node_Id := First_Index (Opnd_Typ);
Indx_Typ : constant Entity_Id := Etype (Index);
Lo : constant Node_Id := Type_Low_Bound (Indx_Typ);
Hi : constant Node_Id := Type_High_Bound (Indx_Typ);
begin
-- Fixed length constrained array type with known at compile
-- time bounds is last case of fixed length operand.
if Compile_Time_Known_Value (Lo)
and then
Compile_Time_Known_Value (Hi)
then
declare
Loval : constant Uint := Expr_Value (Lo);
Hival : constant Uint := Expr_Value (Hi);
Len : constant Uint :=
UI_Max (Hival - Loval + 1, Uint_0);
begin
if Len > 0 then
Result_May_Be_Null := False;
end if;
-- Capture last operand bounds if result could be null
if J = N and then Result_May_Be_Null then
Last_Opnd_Low_Bound :=
Convert_To (Ityp,
Make_Integer_Literal (Loc, Expr_Value (Lo)));
Last_Opnd_High_Bound :=
Convert_To (Ityp,
Make_Integer_Literal (Loc, Expr_Value (Hi)));
end if;
-- Exclude null length case unless last operand
if J < N and then Len = 0 then
goto Continue;
end if;
NN := NN + 1;
Operands (NN) := Opnd;
Is_Fixed_Length (NN) := True;
Fixed_Length (NN) := Len;
Opnd_Low_Bound (NN) :=
To_Ityp
(Make_Integer_Literal (Loc, Expr_Value (Lo)));
Set := True;
end;
end if;
end;
end if;
-- All cases where the length is not known at compile time, or the
-- special case of an operand which is known to be null but has a
-- lower bound other than 1 or is other than a string type.
if not Set then
NN := NN + 1;
-- Capture operand bounds
Opnd_Low_Bound (NN) :=
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr (Opnd, Name_Req => True),
Attribute_Name => Name_First);
Set_Parent (Opnd_Low_Bound (NN), Opnd);
-- Capture last operand bounds if result could be null
if J = N and Result_May_Be_Null then
Last_Opnd_Low_Bound :=
Convert_To (Ityp,
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr (Opnd, Name_Req => True),
Attribute_Name => Name_First));
Set_Parent (Last_Opnd_Low_Bound, Opnd);
Last_Opnd_High_Bound :=
Convert_To (Ityp,
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr (Opnd, Name_Req => True),
Attribute_Name => Name_Last));
Set_Parent (Last_Opnd_High_Bound, Opnd);
end if;
-- Capture length of operand in entity
Operands (NN) := Opnd;
Is_Fixed_Length (NN) := False;
Var_Length (NN) := Make_Temporary (Loc, 'L');
Append_To (Actions,
Make_Object_Declaration (Loc,
Defining_Identifier => Var_Length (NN),
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Artyp, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr (Opnd, Name_Req => True),
Attribute_Name => Name_Length)));
end if;
end if;
-- Set next entry in aggregate length array
-- For first entry, make either integer literal for fixed length
-- or a reference to the saved length for variable length.
if NN = 1 then
if Is_Fixed_Length (1) then
Aggr_Length (1) := Make_Integer_Literal (Loc, Fixed_Length (1));
else
Aggr_Length (1) := New_Reference_To (Var_Length (1), Loc);
end if;
-- If entry is fixed length and only fixed lengths so far, make
-- appropriate new integer literal adding new length.
elsif Is_Fixed_Length (NN)
and then Nkind (Aggr_Length (NN - 1)) = N_Integer_Literal
then
Aggr_Length (NN) :=
Make_Integer_Literal (Loc,
Intval => Fixed_Length (NN) + Intval (Aggr_Length (NN - 1)));
-- All other cases, construct an addition node for the length and
-- create an entity initialized to this length.
else
Ent := Make_Temporary (Loc, 'L');
if Is_Fixed_Length (NN) then
Clen := Make_Integer_Literal (Loc, Fixed_Length (NN));
else
Clen := New_Reference_To (Var_Length (NN), Loc);
end if;
Append_To (Actions,
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Artyp, Loc),
Expression =>
Make_Op_Add (Loc,
Left_Opnd => New_Copy (Aggr_Length (NN - 1)),
Right_Opnd => Clen)));
Aggr_Length (NN) := Make_Identifier (Loc, Chars => Chars (Ent));
end if;
<<Continue>>
J := J + 1;
end loop;
-- If we have only skipped null operands, return the last operand
if NN = 0 then
Result := Opnd;
goto Done;
end if;
-- If we have only one non-null operand, return it and we are done.
-- There is one case in which this cannot be done, and that is when
-- the sole operand is of the element type, in which case it must be
-- converted to an array, and the easiest way of doing that is to go
-- through the normal general circuit.
if NN = 1
and then Base_Type (Etype (Operands (1))) /= Ctyp
then
Result := Operands (1);
goto Done;
end if;
-- Cases where we have a real concatenation
-- Next step is to find the low bound for the result array that we
-- will allocate. The rules for this are in (RM 4.5.6(5-7)).
-- If the ultimate ancestor of the index subtype is a constrained array
-- definition, then the lower bound is that of the index subtype as
-- specified by (RM 4.5.3(6)).
-- The right test here is to go to the root type, and then the ultimate
-- ancestor is the first subtype of this root type.
if Is_Constrained (First_Subtype (Root_Type (Atyp))) then
Low_Bound :=
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (First_Subtype (Root_Type (Atyp)), Loc),
Attribute_Name => Name_First);
-- If the first operand in the list has known length we know that
-- the lower bound of the result is the lower bound of this operand.
elsif Is_Fixed_Length (1) then
Low_Bound := Opnd_Low_Bound (1);
-- OK, we don't know the lower bound, we have to build a horrible
-- if expression node of the form
-- if Cond1'Length /= 0 then
-- Opnd1 low bound
-- else
-- if Opnd2'Length /= 0 then
-- Opnd2 low bound
-- else
-- ...
-- The nesting ends either when we hit an operand whose length is known
-- at compile time, or on reaching the last operand, whose low bound we
-- take unconditionally whether or not it is null. It's easiest to do
-- this with a recursive procedure:
else
declare
function Get_Known_Bound (J : Nat) return Node_Id;
-- Returns the lower bound determined by operands J .. NN
---------------------
-- Get_Known_Bound --
---------------------
function Get_Known_Bound (J : Nat) return Node_Id is
begin
if Is_Fixed_Length (J) or else J = NN then
return New_Copy (Opnd_Low_Bound (J));
else
return
Make_If_Expression (Loc,
Expressions => New_List (
Make_Op_Ne (Loc,
Left_Opnd => New_Reference_To (Var_Length (J), Loc),
Right_Opnd => Make_Integer_Literal (Loc, 0)),
New_Copy (Opnd_Low_Bound (J)),
Get_Known_Bound (J + 1)));
end if;
end Get_Known_Bound;
begin
Ent := Make_Temporary (Loc, 'L');
Append_To (Actions,
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Ityp, Loc),
Expression => Get_Known_Bound (1)));
Low_Bound := New_Reference_To (Ent, Loc);
end;
end if;
-- Now we can safely compute the upper bound, normally
-- Low_Bound + Length - 1.
High_Bound :=
To_Ityp (
Make_Op_Add (Loc,
Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
Right_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd => New_Copy (Aggr_Length (NN)),
Right_Opnd => Make_Artyp_Literal (1))));
-- Note that calculation of the high bound may cause overflow in some
-- very weird cases, so in the general case we need an overflow check on
-- the high bound. We can avoid this for the common case of string types
-- and other types whose index is Positive, since we chose a wider range
-- for the arithmetic type.
if Istyp /= Standard_Positive then
Activate_Overflow_Check (High_Bound);
end if;
-- Handle the exceptional case where the result is null, in which case
-- case the bounds come from the last operand (so that we get the proper
-- bounds if the last operand is super-flat).
if Result_May_Be_Null then
Low_Bound :=
Make_If_Expression (Loc,
Expressions => New_List (
Make_Op_Eq (Loc,
Left_Opnd => New_Copy (Aggr_Length (NN)),
Right_Opnd => Make_Artyp_Literal (0)),
Last_Opnd_Low_Bound,
Low_Bound));
High_Bound :=
Make_If_Expression (Loc,
Expressions => New_List (
Make_Op_Eq (Loc,
Left_Opnd => New_Copy (Aggr_Length (NN)),
Right_Opnd => Make_Artyp_Literal (0)),
Last_Opnd_High_Bound,
High_Bound));
end if;
-- Here is where we insert the saved up actions
Insert_Actions (Cnode, Actions, Suppress => All_Checks);
-- Now we construct an array object with appropriate bounds. We mark
-- the target as internal to prevent useless initialization when
-- Initialize_Scalars is enabled. Also since this is the actual result
-- entity, we make sure we have debug information for the result.
Ent := Make_Temporary (Loc, 'S');
Set_Is_Internal (Ent);
Set_Needs_Debug_Info (Ent);
-- If the bound is statically known to be out of range, we do not want
-- to abort, we want a warning and a runtime constraint error. Note that
-- we have arranged that the result will not be treated as a static
-- constant, so we won't get an illegality during this insertion.
Insert_Action (Cnode,
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Object_Definition =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Atyp, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
Make_Range (Loc,
Low_Bound => Low_Bound,
High_Bound => High_Bound))))),
Suppress => All_Checks);
-- If the result of the concatenation appears as the initializing
-- expression of an object declaration, we can just rename the
-- result, rather than copying it.
Set_OK_To_Rename (Ent);
-- Catch the static out of range case now
if Raises_Constraint_Error (High_Bound) then
raise Concatenation_Error;
end if;
-- Now we will generate the assignments to do the actual concatenation
-- There is one case in which we will not do this, namely when all the
-- following conditions are met:
-- The result type is Standard.String
-- There are nine or fewer retained (non-null) operands
-- The optimization level is -O0
-- The corresponding System.Concat_n.Str_Concat_n routine is
-- available in the run time.
-- The debug flag gnatd.c is not set
-- If all these conditions are met then we generate a call to the
-- relevant concatenation routine. The purpose of this is to avoid
-- undesirable code bloat at -O0.
if Atyp = Standard_String
and then NN in 2 .. 9
and then (Opt.Optimization_Level = 0 or else Debug_Flag_Dot_CC)
and then not Debug_Flag_Dot_C
then
declare
RR : constant array (Nat range 2 .. 9) of RE_Id :=
(RE_Str_Concat_2,
RE_Str_Concat_3,
RE_Str_Concat_4,
RE_Str_Concat_5,
RE_Str_Concat_6,
RE_Str_Concat_7,
RE_Str_Concat_8,
RE_Str_Concat_9);
begin
if RTE_Available (RR (NN)) then
declare
Opnds : constant List_Id :=
New_List (New_Occurrence_Of (Ent, Loc));
begin
for J in 1 .. NN loop
if Is_List_Member (Operands (J)) then
Remove (Operands (J));
end if;
if Base_Type (Etype (Operands (J))) = Ctyp then
Append_To (Opnds,
Make_Aggregate (Loc,
Component_Associations => New_List (
Make_Component_Association (Loc,
Choices => New_List (
Make_Integer_Literal (Loc, 1)),
Expression => Operands (J)))));
else
Append_To (Opnds, Operands (J));
end if;
end loop;
Insert_Action (Cnode,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RR (NN)), Loc),
Parameter_Associations => Opnds));
Result := New_Reference_To (Ent, Loc);
goto Done;
end;
end if;
end;
end if;
-- Not special case so generate the assignments
Known_Non_Null_Operand_Seen := False;
for J in 1 .. NN loop
declare
Lo : constant Node_Id :=
Make_Op_Add (Loc,
Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
Right_Opnd => Aggr_Length (J - 1));
Hi : constant Node_Id :=
Make_Op_Add (Loc,
Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
Right_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd => Aggr_Length (J),
Right_Opnd => Make_Artyp_Literal (1)));
begin
-- Singleton case, simple assignment
if Base_Type (Etype (Operands (J))) = Ctyp then
Known_Non_Null_Operand_Seen := True;
Insert_Action (Cnode,
Make_Assignment_Statement (Loc,
Name =>
Make_Indexed_Component (Loc,
Prefix => New_Occurrence_Of (Ent, Loc),
Expressions => New_List (To_Ityp (Lo))),
Expression => Operands (J)),
Suppress => All_Checks);
-- Array case, slice assignment, skipped when argument is fixed
-- length and known to be null.
elsif (not Is_Fixed_Length (J)) or else (Fixed_Length (J) > 0) then
declare
Assign : Node_Id :=
Make_Assignment_Statement (Loc,
Name =>
Make_Slice (Loc,
Prefix =>
New_Occurrence_Of (Ent, Loc),
Discrete_Range =>
Make_Range (Loc,
Low_Bound => To_Ityp (Lo),
High_Bound => To_Ityp (Hi))),
Expression => Operands (J));
begin
if Is_Fixed_Length (J) then
Known_Non_Null_Operand_Seen := True;
elsif not Known_Non_Null_Operand_Seen then
-- Here if operand length is not statically known and no
-- operand known to be non-null has been processed yet.
-- If operand length is 0, we do not need to perform the
-- assignment, and we must avoid the evaluation of the
-- high bound of the slice, since it may underflow if the
-- low bound is Ityp'First.
Assign :=
Make_Implicit_If_Statement (Cnode,
Condition =>
Make_Op_Ne (Loc,
Left_Opnd =>
New_Occurrence_Of (Var_Length (J), Loc),
Right_Opnd => Make_Integer_Literal (Loc, 0)),
Then_Statements => New_List (Assign));
end if;
Insert_Action (Cnode, Assign, Suppress => All_Checks);
end;
end if;
end;
end loop;
-- Finally we build the result, which is a reference to the array object
Result := New_Reference_To (Ent, Loc);
<<Done>>
Rewrite (Cnode, Result);
Analyze_And_Resolve (Cnode, Atyp);
exception
when Concatenation_Error =>
-- Kill warning generated for the declaration of the static out of
-- range high bound, and instead generate a Constraint_Error with
-- an appropriate specific message.
Kill_Dead_Code (Declaration_Node (Entity (High_Bound)));
Apply_Compile_Time_Constraint_Error
(N => Cnode,
Msg => "concatenation result upper bound out of range??",
Reason => CE_Range_Check_Failed);
end Expand_Concatenate;
---------------------------------------------------
-- Expand_Membership_Minimize_Eliminate_Overflow --
---------------------------------------------------
procedure Expand_Membership_Minimize_Eliminate_Overflow (N : Node_Id) is
pragma Assert (Nkind (N) = N_In);
-- Despite the name, this routine applies only to N_In, not to
-- N_Not_In. The latter is always rewritten as not (X in Y).
Result_Type : constant Entity_Id := Etype (N);
-- Capture result type, may be a derived boolean type
Loc : constant Source_Ptr := Sloc (N);
Lop : constant Node_Id := Left_Opnd (N);
Rop : constant Node_Id := Right_Opnd (N);
-- Note: there are many referencs to Etype (Lop) and Etype (Rop). It
-- is thus tempting to capture these values, but due to the rewrites
-- that occur as a result of overflow checking, these values change
-- as we go along, and it is safe just to always use Etype explicitly.
Restype : constant Entity_Id := Etype (N);
-- Save result type
Lo, Hi : Uint;
-- Bounds in Minimize calls, not used currently
LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer);
-- Entity for Long_Long_Integer'Base (Standard should export this???)
begin
Minimize_Eliminate_Overflows (Lop, Lo, Hi, Top_Level => False);
-- If right operand is a subtype name, and the subtype name has no
-- predicate, then we can just replace the right operand with an
-- explicit range T'First .. T'Last, and use the explicit range code.
if Nkind (Rop) /= N_Range
and then No (Predicate_Function (Etype (Rop)))
then
declare
Rtyp : constant Entity_Id := Etype (Rop);
begin
Rewrite (Rop,
Make_Range (Loc,
Low_Bound =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Reference_To (Rtyp, Loc)),
High_Bound =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Reference_To (Rtyp, Loc))));
Analyze_And_Resolve (Rop, Rtyp, Suppress => All_Checks);
end;
end if;
-- Here for the explicit range case. Note that the bounds of the range
-- have not been processed for minimized or eliminated checks.
if Nkind (Rop) = N_Range then
Minimize_Eliminate_Overflows
(Low_Bound (Rop), Lo, Hi, Top_Level => False);
Minimize_Eliminate_Overflows
(High_Bound (Rop), Lo, Hi, Top_Level => False);
-- We have A in B .. C, treated as A >= B and then A <= C
-- Bignum case
if Is_RTE (Etype (Lop), RE_Bignum)
or else Is_RTE (Etype (Low_Bound (Rop)), RE_Bignum)
or else Is_RTE (Etype (High_Bound (Rop)), RE_Bignum)
then
declare
Blk : constant Node_Id := Make_Bignum_Block (Loc);
Bnn : constant Entity_Id := Make_Temporary (Loc, 'B', N);
L : constant Entity_Id :=
Make_Defining_Identifier (Loc, Name_uL);
Lopnd : constant Node_Id := Convert_To_Bignum (Lop);
Lbound : constant Node_Id :=
Convert_To_Bignum (Low_Bound (Rop));
Hbound : constant Node_Id :=
Convert_To_Bignum (High_Bound (Rop));
-- Now we rewrite the membership test node to look like
-- do
-- Bnn : Result_Type;
-- declare
-- M : Mark_Id := SS_Mark;
-- L : Bignum := Lopnd;
-- begin
-- Bnn := Big_GE (L, Lbound) and then Big_LE (L, Hbound)
-- SS_Release (M);
-- end;
-- in
-- Bnn
-- end
begin
-- Insert declaration of L into declarations of bignum block
Insert_After
(Last (Declarations (Blk)),
Make_Object_Declaration (Loc,
Defining_Identifier => L,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Bignum), Loc),
Expression => Lopnd));
-- Insert assignment to Bnn into expressions of bignum block
Insert_Before
(First (Statements (Handled_Statement_Sequence (Blk))),
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Bnn, Loc),
Expression =>
Make_And_Then (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Big_GE), Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (L, Loc),
Lbound)),
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Big_LE), Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (L, Loc),
Hbound)))));
-- Now rewrite the node
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => Bnn,
Object_Definition =>
New_Occurrence_Of (Result_Type, Loc)),
Blk),
Expression => New_Occurrence_Of (Bnn, Loc)));
Analyze_And_Resolve (N, Result_Type);
return;
end;
-- Here if no bignums around
else
-- Case where types are all the same
if Base_Type (Etype (Lop)) = Base_Type (Etype (Low_Bound (Rop)))
and then
Base_Type (Etype (Lop)) = Base_Type (Etype (High_Bound (Rop)))
then
null;
-- If types are not all the same, it means that we have rewritten
-- at least one of them to be of type Long_Long_Integer, and we
-- will convert the other operands to Long_Long_Integer.
else
Convert_To_And_Rewrite (LLIB, Lop);
Set_Analyzed (Lop, False);
Analyze_And_Resolve (Lop, LLIB);
-- For the right operand, avoid unnecessary recursion into
-- this routine, we know that overflow is not possible.
Convert_To_And_Rewrite (LLIB, Low_Bound (Rop));
Convert_To_And_Rewrite (LLIB, High_Bound (Rop));
Set_Analyzed (Rop, False);
Analyze_And_Resolve (Rop, LLIB, Suppress => Overflow_Check);
end if;
-- Now the three operands are of the same signed integer type,
-- so we can use the normal expansion routine for membership,
-- setting the flag to prevent recursion into this procedure.
Set_No_Minimize_Eliminate (N);
Expand_N_In (N);
end if;
-- Right operand is a subtype name and the subtype has a predicate. We
-- have to make sure the predicate is checked, and for that we need to
-- use the standard N_In circuitry with appropriate types.
else
pragma Assert (Present (Predicate_Function (Etype (Rop))));
-- If types are "right", just call Expand_N_In preventing recursion
if Base_Type (Etype (Lop)) = Base_Type (Etype (Rop)) then
Set_No_Minimize_Eliminate (N);
Expand_N_In (N);
-- Bignum case
elsif Is_RTE (Etype (Lop), RE_Bignum) then
-- For X in T, we want to rewrite our node as
-- do
-- Bnn : Result_Type;
-- declare
-- M : Mark_Id := SS_Mark;
-- Lnn : Long_Long_Integer'Base
-- Nnn : Bignum;
-- begin
-- Nnn := X;
-- if not Bignum_In_LLI_Range (Nnn) then
-- Bnn := False;
-- else
-- Lnn := From_Bignum (Nnn);
-- Bnn :=
-- Lnn in LLIB (T'Base'First) .. LLIB (T'Base'Last)
-- and then T'Base (Lnn) in T;
-- end if;
--
-- SS_Release (M);
-- end
-- in
-- Bnn
-- end
-- A bit gruesome, but there doesn't seem to be a simpler way
declare
Blk : constant Node_Id := Make_Bignum_Block (Loc);
Bnn : constant Entity_Id := Make_Temporary (Loc, 'B', N);
Lnn : constant Entity_Id := Make_Temporary (Loc, 'L', N);
Nnn : constant Entity_Id := Make_Temporary (Loc, 'N', N);
T : constant Entity_Id := Etype (Rop);
TB : constant Entity_Id := Base_Type (T);
Nin : Node_Id;
begin
-- Mark the last membership operation to prevent recursion
Nin :=
Make_In (Loc,
Left_Opnd => Convert_To (TB, New_Occurrence_Of (Lnn, Loc)),
Right_Opnd => New_Occurrence_Of (T, Loc));
Set_No_Minimize_Eliminate (Nin);
-- Now decorate the block
Insert_After
(Last (Declarations (Blk)),
Make_Object_Declaration (Loc,
Defining_Identifier => Lnn,
Object_Definition => New_Occurrence_Of (LLIB, Loc)));
Insert_After
(Last (Declarations (Blk)),
Make_Object_Declaration (Loc,
Defining_Identifier => Nnn,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Bignum), Loc)));
Insert_List_Before
(First (Statements (Handled_Statement_Sequence (Blk))),
New_List (
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Nnn, Loc),
Expression => Relocate_Node (Lop)),
Make_If_Statement (Loc,
Condition =>
Make_Op_Not (Loc,
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of
(RTE (RE_Bignum_In_LLI_Range), Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (Nnn, Loc)))),
Then_Statements => New_List (
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Bnn, Loc),
Expression =>
New_Occurrence_Of (Standard_False, Loc))),
Else_Statements => New_List (
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Lnn, Loc),
Expression =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_From_Bignum), Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (Nnn, Loc)))),
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Bnn, Loc),
Expression =>
Make_And_Then (Loc,
Left_Opnd =>
Make_In (Loc,
Left_Opnd => New_Occurrence_Of (Lnn, Loc),
Right_Opnd =>
Make_Range (Loc,
Low_Bound =>
Convert_To (LLIB,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix =>
New_Occurrence_Of (TB, Loc))),
High_Bound =>
Convert_To (LLIB,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix =>
New_Occurrence_Of (TB, Loc))))),
Right_Opnd => Nin))))));
-- Now we can do the rewrite
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => Bnn,
Object_Definition =>
New_Occurrence_Of (Result_Type, Loc)),
Blk),
Expression => New_Occurrence_Of (Bnn, Loc)));
Analyze_And_Resolve (N, Result_Type);
return;
end;
-- Not bignum case, but types don't match (this means we rewrote the
-- left operand to be Long_Long_Integer).
else
pragma Assert (Base_Type (Etype (Lop)) = LLIB);
-- We rewrite the membership test as (where T is the type with
-- the predicate, i.e. the type of the right operand)
-- Lop in LLIB (T'Base'First) .. LLIB (T'Base'Last)
-- and then T'Base (Lop) in T
declare
T : constant Entity_Id := Etype (Rop);
TB : constant Entity_Id := Base_Type (T);
Nin : Node_Id;
begin
-- The last membership test is marked to prevent recursion
Nin :=
Make_In (Loc,
Left_Opnd => Convert_To (TB, Duplicate_Subexpr (Lop)),
Right_Opnd => New_Occurrence_Of (T, Loc));
Set_No_Minimize_Eliminate (Nin);
-- Now do the rewrite
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd =>
Make_In (Loc,
Left_Opnd => Lop,
Right_Opnd =>
Make_Range (Loc,
Low_Bound =>
Convert_To (LLIB,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Occurrence_Of (TB, Loc))),
High_Bound =>
Convert_To (LLIB,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Occurrence_Of (TB, Loc))))),
Right_Opnd => Nin));
Set_Analyzed (N, False);
Analyze_And_Resolve (N, Restype);
end;
end if;
end if;
end Expand_Membership_Minimize_Eliminate_Overflow;
------------------------
-- Expand_N_Allocator --
------------------------
procedure Expand_N_Allocator (N : Node_Id) is
PtrT : constant Entity_Id := Etype (N);
Dtyp : constant Entity_Id := Available_View (Designated_Type (PtrT));
Etyp : constant Entity_Id := Etype (Expression (N));
Loc : constant Source_Ptr := Sloc (N);
Desig : Entity_Id;
Nod : Node_Id;
Pool : Entity_Id;
Temp : Entity_Id;
procedure Rewrite_Coextension (N : Node_Id);
-- Static coextensions have the same lifetime as the entity they
-- constrain. Such occurrences can be rewritten as aliased objects
-- and their unrestricted access used instead of the coextension.
function Size_In_Storage_Elements (E : Entity_Id) return Node_Id;
-- Given a constrained array type E, returns a node representing the
-- code to compute the size in storage elements for the given type.
-- This is done without using the attribute (which malfunctions for
-- large sizes ???)
-------------------------
-- Rewrite_Coextension --
-------------------------
procedure Rewrite_Coextension (N : Node_Id) is
Temp_Id : constant Node_Id := Make_Temporary (Loc, 'C');
Temp_Decl : Node_Id;
begin
-- Generate:
-- Cnn : aliased Etyp;
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp_Id,
Aliased_Present => True,
Object_Definition => New_Occurrence_Of (Etyp, Loc));
if Nkind (Expression (N)) = N_Qualified_Expression then
Set_Expression (Temp_Decl, Expression (Expression (N)));
end if;
Insert_Action (N, Temp_Decl);
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Temp_Id, Loc),
Attribute_Name => Name_Unrestricted_Access));
Analyze_And_Resolve (N, PtrT);
end Rewrite_Coextension;
------------------------------
-- Size_In_Storage_Elements --
------------------------------
function Size_In_Storage_Elements (E : Entity_Id) return Node_Id is
begin
-- Logically this just returns E'Max_Size_In_Storage_Elements.
-- However, the reason for the existence of this function is
-- to construct a test for sizes too large, which means near the
-- 32-bit limit on a 32-bit machine, and precisely the trouble
-- is that we get overflows when sizes are greater than 2**31.
-- So what we end up doing for array types is to use the expression:
-- number-of-elements * component_type'Max_Size_In_Storage_Elements
-- which avoids this problem. All this is a bit bogus, but it does
-- mean we catch common cases of trying to allocate arrays that
-- are too large, and which in the absence of a check results in
-- undetected chaos ???
declare
Len : Node_Id;
Res : Node_Id;
begin
for J in 1 .. Number_Dimensions (E) loop
Len :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (E, Loc),
Attribute_Name => Name_Length,
Expressions => New_List (Make_Integer_Literal (Loc, J)));
if J = 1 then
Res := Len;
else
Res :=
Make_Op_Multiply (Loc,
Left_Opnd => Res,
Right_Opnd => Len);
end if;
end loop;
return
Make_Op_Multiply (Loc,
Left_Opnd => Len,
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Component_Type (E), Loc),
Attribute_Name => Name_Max_Size_In_Storage_Elements));
end;
end Size_In_Storage_Elements;
-- Start of processing for Expand_N_Allocator
begin
-- RM E.2.3(22). We enforce that the expected type of an allocator
-- shall not be a remote access-to-class-wide-limited-private type
-- Why is this being done at expansion time, seems clearly wrong ???
Validate_Remote_Access_To_Class_Wide_Type (N);
-- Processing for anonymous access-to-controlled types. These access
-- types receive a special finalization master which appears in the
-- declarations of the enclosing semantic unit. This expansion is done
-- now to ensure that any additional types generated by this routine or
-- Expand_Allocator_Expression inherit the proper type attributes.
if (Ekind (PtrT) = E_Anonymous_Access_Type
or else
(Is_Itype (PtrT) and then No (Finalization_Master (PtrT))))
and then Needs_Finalization (Dtyp)
then
-- Anonymous access-to-controlled types allocate on the global pool.
-- Do not set this attribute on .NET/JVM since those targets do not
-- support pools.
if No (Associated_Storage_Pool (PtrT)) and then VM_Target = No_VM then
Set_Associated_Storage_Pool
(PtrT, Get_Global_Pool_For_Access_Type (PtrT));
end if;
-- The finalization master must be inserted and analyzed as part of
-- the current semantic unit. This form of expansion is not carried
-- out in Alfa mode because it is useless. Note that the master is
-- updated when analysis changes current units.
if not Alfa_Mode then
Set_Finalization_Master (PtrT, Current_Anonymous_Master);
end if;
end if;
-- Set the storage pool and find the appropriate version of Allocate to
-- call. Do not overwrite the storage pool if it is already set, which
-- can happen for build-in-place function returns (see
-- Exp_Ch4.Expand_N_Extended_Return_Statement).
if No (Storage_Pool (N)) then
Pool := Associated_Storage_Pool (Root_Type (PtrT));
if Present (Pool) then
Set_Storage_Pool (N, Pool);
if Is_RTE (Pool, RE_SS_Pool) then
if VM_Target = No_VM then
Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
end if;
-- In the case of an allocator for a simple storage pool, locate
-- and save a reference to the pool type's Allocate routine.
elsif Present (Get_Rep_Pragma
(Etype (Pool), Name_Simple_Storage_Pool_Type))
then
declare
Pool_Type : constant Entity_Id := Base_Type (Etype (Pool));
Alloc_Op : Entity_Id;
begin
Alloc_Op := Get_Name_Entity_Id (Name_Allocate);
while Present (Alloc_Op) loop
if Scope (Alloc_Op) = Scope (Pool_Type)
and then Present (First_Formal (Alloc_Op))
and then Etype (First_Formal (Alloc_Op)) = Pool_Type
then
Set_Procedure_To_Call (N, Alloc_Op);
exit;
else
Alloc_Op := Homonym (Alloc_Op);
end if;
end loop;
end;
elsif Is_Class_Wide_Type (Etype (Pool)) then
Set_Procedure_To_Call (N, RTE (RE_Allocate_Any));
else
Set_Procedure_To_Call (N,
Find_Prim_Op (Etype (Pool), Name_Allocate));
end if;
end if;
end if;
-- Under certain circumstances we can replace an allocator by an access
-- to statically allocated storage. The conditions, as noted in AARM
-- 3.10 (10c) are as follows:
-- Size and initial value is known at compile time
-- Access type is access-to-constant
-- The allocator is not part of a constraint on a record component,
-- because in that case the inserted actions are delayed until the
-- record declaration is fully analyzed, which is too late for the
-- analysis of the rewritten allocator.
if Is_Access_Constant (PtrT)
and then Nkind (Expression (N)) = N_Qualified_Expression
and then Compile_Time_Known_Value (Expression (Expression (N)))
and then Size_Known_At_Compile_Time
(Etype (Expression (Expression (N))))
and then not Is_Record_Type (Current_Scope)
then
-- Here we can do the optimization. For the allocator
-- new x'(y)
-- We insert an object declaration
-- Tnn : aliased x := y;
-- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
-- marked as requiring static allocation.
Temp := Make_Temporary (Loc, 'T', Expression (Expression (N)));
Desig := Subtype_Mark (Expression (N));
-- If context is constrained, use constrained subtype directly,
-- so that the constant is not labelled as having a nominally
-- unconstrained subtype.
if Entity (Desig) = Base_Type (Dtyp) then
Desig := New_Occurrence_Of (Dtyp, Loc);
end if;
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Aliased_Present => True,
Constant_Present => Is_Access_Constant (PtrT),
Object_Definition => Desig,
Expression => Expression (Expression (N))));
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Temp, Loc),
Attribute_Name => Name_Unrestricted_Access));
Analyze_And_Resolve (N, PtrT);
-- We set the variable as statically allocated, since we don't want
-- it going on the stack of the current procedure!
Set_Is_Statically_Allocated (Temp);
return;
end if;
-- Same if the allocator is an access discriminant for a local object:
-- instead of an allocator we create a local value and constrain the
-- enclosing object with the corresponding access attribute.
if Is_Static_Coextension (N) then
Rewrite_Coextension (N);
return;
end if;
-- Check for size too large, we do this because the back end misses
-- proper checks here and can generate rubbish allocation calls when
-- we are near the limit. We only do this for the 32-bit address case
-- since that is from a practical point of view where we see a problem.
if System_Address_Size = 32
and then not Storage_Checks_Suppressed (PtrT)
and then not Storage_Checks_Suppressed (Dtyp)
and then not Storage_Checks_Suppressed (Etyp)
then
-- The check we want to generate should look like
-- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then
-- raise Storage_Error;
-- end if;
-- where 3.5 gigabytes is a constant large enough to accommodate any
-- reasonable request for. But we can't do it this way because at
-- least at the moment we don't compute this attribute right, and
-- can silently give wrong results when the result gets large. Since
-- this is all about large results, that's bad, so instead we only
-- apply the check for constrained arrays, and manually compute the
-- value of the attribute ???
if Is_Array_Type (Etyp) and then Is_Constrained (Etyp) then
Insert_Action (N,
Make_Raise_Storage_Error (Loc,
Condition =>
Make_Op_Gt (Loc,
Left_Opnd => Size_In_Storage_Elements (Etyp),
Right_Opnd =>
Make_Integer_Literal (Loc, Uint_7 * (Uint_2 ** 29))),
Reason => SE_Object_Too_Large));
end if;
end if;
-- Handle case of qualified expression (other than optimization above)
-- First apply constraint checks, because the bounds or discriminants
-- in the aggregate might not match the subtype mark in the allocator.
if Nkind (Expression (N)) = N_Qualified_Expression then
Apply_Constraint_Check
(Expression (Expression (N)), Etype (Expression (N)));
Expand_Allocator_Expression (N);
return;
end if;
-- If the allocator is for a type which requires initialization, and
-- there is no initial value (i.e. operand is a subtype indication
-- rather than a qualified expression), then we must generate a call to
-- the initialization routine using an expressions action node:
-- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
-- Here ptr_T is the pointer type for the allocator, and T is the
-- subtype of the allocator. A special case arises if the designated
-- type of the access type is a task or contains tasks. In this case
-- the call to Init (Temp.all ...) is replaced by code that ensures
-- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
-- for details). In addition, if the type T is a task T, then the
-- first argument to Init must be converted to the task record type.
declare
T : constant Entity_Id := Entity (Expression (N));
Args : List_Id;
Decls : List_Id;
Decl : Node_Id;
Discr : Elmt_Id;
Init : Entity_Id;
Init_Arg1 : Node_Id;
Temp_Decl : Node_Id;
Temp_Type : Entity_Id;
begin
if No_Initialization (N) then
-- Even though this might be a simple allocation, create a custom
-- Allocate if the context requires it. Since .NET/JVM compilers
-- do not support pools, this step is skipped.
if VM_Target = No_VM
and then Present (Finalization_Master (PtrT))
then
Build_Allocate_Deallocate_Proc
(N => N,
Is_Allocate => True);
end if;
-- Case of no initialization procedure present
elsif not Has_Non_Null_Base_Init_Proc (T) then
-- Case of simple initialization required
if Needs_Simple_Initialization (T) then
Check_Restriction (No_Default_Initialization, N);
Rewrite (Expression (N),
Make_Qualified_Expression (Loc,
Subtype_Mark => New_Occurrence_Of (T, Loc),
Expression => Get_Simple_Init_Val (T, N)));
Analyze_And_Resolve (Expression (Expression (N)), T);
Analyze_And_Resolve (Expression (N), T);
Set_Paren_Count (Expression (Expression (N)), 1);
Expand_N_Allocator (N);
-- No initialization required
else
null;
end if;
-- Case of initialization procedure present, must be called
else
Check_Restriction (No_Default_Initialization, N);
if not Restriction_Active (No_Default_Initialization) then
Init := Base_Init_Proc (T);
Nod := N;
Temp := Make_Temporary (Loc, 'P');
-- Construct argument list for the initialization routine call
Init_Arg1 :=
Make_Explicit_Dereference (Loc,
Prefix =>
New_Reference_To (Temp, Loc));
Set_Assignment_OK (Init_Arg1);
Temp_Type := PtrT;
-- The initialization procedure expects a specific type. if the
-- context is access to class wide, indicate that the object
-- being allocated has the right specific type.
if Is_Class_Wide_Type (Dtyp) then
Init_Arg1 := Unchecked_Convert_To (T, Init_Arg1);
end if;
-- If designated type is a concurrent type or if it is private
-- type whose definition is a concurrent type, the first
-- argument in the Init routine has to be unchecked conversion
-- to the corresponding record type. If the designated type is
-- a derived type, also convert the argument to its root type.
if Is_Concurrent_Type (T) then
Init_Arg1 :=
Unchecked_Convert_To (
Corresponding_Record_Type (T), Init_Arg1);
elsif Is_Private_Type (T)
and then Present (Full_View (T))
and then Is_Concurrent_Type (Full_View (T))
then
Init_Arg1 :=
Unchecked_Convert_To
(Corresponding_Record_Type (Full_View (T)), Init_Arg1);
elsif Etype (First_Formal (Init)) /= Base_Type (T) then
declare
Ftyp : constant Entity_Id := Etype (First_Formal (Init));
begin
Init_Arg1 := OK_Convert_To (Etype (Ftyp), Init_Arg1);
Set_Etype (Init_Arg1, Ftyp);
end;
end if;
Args := New_List (Init_Arg1);
-- For the task case, pass the Master_Id of the access type as
-- the value of the _Master parameter, and _Chain as the value
-- of the _Chain parameter (_Chain will be defined as part of
-- the generated code for the allocator).
-- In Ada 2005, the context may be a function that returns an
-- anonymous access type. In that case the Master_Id has been
-- created when expanding the function declaration.
if Has_Task (T) then
if No (Master_Id (Base_Type (PtrT))) then
-- The designated type was an incomplete type, and the
-- access type did not get expanded. Salvage it now.
if not Restriction_Active (No_Task_Hierarchy) then
pragma Assert (Present (Parent (Base_Type (PtrT))));
Expand_N_Full_Type_Declaration
(Parent (Base_Type (PtrT)));
end if;
end if;
-- If the context of the allocator is a declaration or an
-- assignment, we can generate a meaningful image for it,
-- even though subsequent assignments might remove the
-- connection between task and entity. We build this image
-- when the left-hand side is a simple variable, a simple
-- indexed assignment or a simple selected component.
if Nkind (Parent (N)) = N_Assignment_Statement then
declare
Nam : constant Node_Id := Name (Parent (N));
begin
if Is_Entity_Name (Nam) then
Decls :=
Build_Task_Image_Decls
(Loc,
New_Occurrence_Of
(Entity (Nam), Sloc (Nam)), T);
elsif Nkind_In (Nam, N_Indexed_Component,
N_Selected_Component)
and then Is_Entity_Name (Prefix (Nam))
then
Decls :=
Build_Task_Image_Decls
(Loc, Nam, Etype (Prefix (Nam)));
else
Decls := Build_Task_Image_Decls (Loc, T, T);
end if;
end;
elsif Nkind (Parent (N)) = N_Object_Declaration then
Decls :=
Build_Task_Image_Decls
(Loc, Defining_Identifier (Parent (N)), T);
else
Decls := Build_Task_Image_Decls (Loc, T, T);
end if;
if Restriction_Active (No_Task_Hierarchy) then
Append_To (Args,
New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc));
else
Append_To (Args,
New_Reference_To
(Master_Id (Base_Type (Root_Type (PtrT))), Loc));
end if;
Append_To (Args, Make_Identifier (Loc, Name_uChain));
Decl := Last (Decls);
Append_To (Args,
New_Occurrence_Of (Defining_Identifier (Decl), Loc));
-- Has_Task is false, Decls not used
else
Decls := No_List;
end if;
-- Add discriminants if discriminated type
declare
Dis : Boolean := False;
Typ : Entity_Id;
begin
if Has_Discriminants (T) then
Dis := True;
Typ := T;
elsif Is_Private_Type (T)
and then Present (Full_View (T))
and then Has_Discriminants (Full_View (T))
then
Dis := True;
Typ := Full_View (T);
end if;
if Dis then
-- If the allocated object will be constrained by the
-- default values for discriminants, then build a subtype
-- with those defaults, and change the allocated subtype
-- to that. Note that this happens in fewer cases in Ada
-- 2005 (AI-363).
if not Is_Constrained (Typ)
and then Present (Discriminant_Default_Value
(First_Discriminant (Typ)))
and then (Ada_Version < Ada_2005
or else not
Effectively_Has_Constrained_Partial_View
(Typ => Typ,
Scop => Current_Scope))
then
Typ := Build_Default_Subtype (Typ, N);
Set_Expression (N, New_Reference_To (Typ, Loc));
end if;
Discr := First_Elmt (Discriminant_Constraint (Typ));
while Present (Discr) loop
Nod := Node (Discr);
Append (New_Copy_Tree (Node (Discr)), Args);
-- AI-416: when the discriminant constraint is an
-- anonymous access type make sure an accessibility
-- check is inserted if necessary (3.10.2(22.q/2))
if Ada_Version >= Ada_2005
and then
Ekind (Etype (Nod)) = E_Anonymous_Access_Type
then
Apply_Accessibility_Check
(Nod, Typ, Insert_Node => Nod);
end if;
Next_Elmt (Discr);
end loop;
end if;
end;
-- We set the allocator as analyzed so that when we analyze
-- the if expression node, we do not get an unwanted recursive
-- expansion of the allocator expression.
Set_Analyzed (N, True);
Nod := Relocate_Node (N);
-- Here is the transformation:
-- input: new Ctrl_Typ
-- output: Temp : constant Ctrl_Typ_Ptr := new Ctrl_Typ;
-- Ctrl_TypIP (Temp.all, ...);
-- [Deep_]Initialize (Temp.all);
-- Here Ctrl_Typ_Ptr is the pointer type for the allocator, and
-- is the subtype of the allocator.
Temp_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Constant_Present => True,
Object_Definition => New_Reference_To (Temp_Type, Loc),
Expression => Nod);
Set_Assignment_OK (Temp_Decl);
Insert_Action (N, Temp_Decl, Suppress => All_Checks);
Build_Allocate_Deallocate_Proc (Temp_Decl, True);
-- If the designated type is a task type or contains tasks,
-- create block to activate created tasks, and insert
-- declaration for Task_Image variable ahead of call.
if Has_Task (T) then
declare
L : constant List_Id := New_List;
Blk : Node_Id;
begin
Build_Task_Allocate_Block (L, Nod, Args);
Blk := Last (L);
Insert_List_Before (First (Declarations (Blk)), Decls);
Insert_Actions (N, L);
end;
else
Insert_Action (N,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Init, Loc),
Parameter_Associations => Args));
end if;
if Needs_Finalization (T) then
-- Generate:
-- [Deep_]Initialize (Init_Arg1);
Insert_Action (N,
Make_Init_Call
(Obj_Ref => New_Copy_Tree (Init_Arg1),
Typ => T));
if Present (Finalization_Master (PtrT)) then
-- Special processing for .NET/JVM, the allocated object
-- is attached to the finalization master. Generate:
-- Attach (<PtrT>FM, Root_Controlled_Ptr (Init_Arg1));
-- Types derived from [Limited_]Controlled are the only
-- ones considered since they have fields Prev and Next.
if VM_Target /= No_VM then
if Is_Controlled (T) then
Insert_Action (N,
Make_Attach_Call
(Obj_Ref => New_Copy_Tree (Init_Arg1),
Ptr_Typ => PtrT));
end if;
-- Default case, generate:
-- Set_Finalize_Address
-- (<PtrT>FM, <T>FD'Unrestricted_Access);
-- Do not generate this call in the following cases:
--
-- * Alfa mode - the call is useless and results in
-- unwanted expansion.
--
-- * CodePeer mode - TSS primitive Finalize_Address is
-- not created in this mode.
elsif not Alfa_Mode
and then not CodePeer_Mode
then
Insert_Action (N,
Make_Set_Finalize_Address_Call
(Loc => Loc,
Typ => T,
Ptr_Typ => PtrT));
end if;
end if;
end if;
Rewrite (N, New_Reference_To (Temp, Loc));
Analyze_And_Resolve (N, PtrT);
end if;
end if;
end;
-- Ada 2005 (AI-251): If the allocator is for a class-wide interface
-- object that has been rewritten as a reference, we displace "this"
-- to reference properly its secondary dispatch table.
if Nkind (N) = N_Identifier
and then Is_Interface (Dtyp)
then
Displace_Allocator_Pointer (N);
end if;
exception
when RE_Not_Available =>
return;
end Expand_N_Allocator;
-----------------------
-- Expand_N_And_Then --
-----------------------
procedure Expand_N_And_Then (N : Node_Id)
renames Expand_Short_Circuit_Operator;
------------------------------
-- Expand_N_Case_Expression --
------------------------------
procedure Expand_N_Case_Expression (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Cstmt : Node_Id;
Tnn : Entity_Id;
Pnn : Entity_Id;
Actions : List_Id;
Ttyp : Entity_Id;
Alt : Node_Id;
Fexp : Node_Id;
begin
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- We expand
-- case X is when A => AX, when B => BX ...
-- to
-- do
-- Tnn : typ;
-- case X is
-- when A =>
-- Tnn := AX;
-- when B =>
-- Tnn := BX;
-- ...
-- end case;
-- in Tnn end;
-- However, this expansion is wrong for limited types, and also
-- wrong for unconstrained types (since the bounds may not be the
-- same in all branches). Furthermore it involves an extra copy
-- for large objects. So we take care of this by using the following
-- modified expansion for non-elementary types:
-- do
-- type Pnn is access all typ;
-- Tnn : Pnn;
-- case X is
-- when A =>
-- T := AX'Unrestricted_Access;
-- when B =>
-- T := BX'Unrestricted_Access;
-- ...
-- end case;
-- in Tnn.all end;
Cstmt :=
Make_Case_Statement (Loc,
Expression => Expression (N),
Alternatives => New_List);
Actions := New_List;
-- Scalar case
if Is_Elementary_Type (Typ) then
Ttyp := Typ;
else
Pnn := Make_Temporary (Loc, 'P');
Append_To (Actions,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Pnn,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication =>
New_Reference_To (Typ, Loc))));
Ttyp := Pnn;
end if;
Tnn := Make_Temporary (Loc, 'T');
Append_To (Actions,
Make_Object_Declaration (Loc,
Defining_Identifier => Tnn,
Object_Definition => New_Occurrence_Of (Ttyp, Loc)));
-- Now process the alternatives
Alt := First (Alternatives (N));
while Present (Alt) loop
declare
Aexp : Node_Id := Expression (Alt);
Aloc : constant Source_Ptr := Sloc (Aexp);
Stats : List_Id;
begin
-- As described above, take Unrestricted_Access for case of non-
-- scalar types, to avoid big copies, and special cases.
if not Is_Elementary_Type (Typ) then
Aexp :=
Make_Attribute_Reference (Aloc,
Prefix => Relocate_Node (Aexp),
Attribute_Name => Name_Unrestricted_Access);
end if;
Stats := New_List (
Make_Assignment_Statement (Aloc,
Name => New_Occurrence_Of (Tnn, Loc),
Expression => Aexp));
-- Propagate declarations inserted in the node by Insert_Actions
-- (for example, temporaries generated to remove side effects).
-- These actions must remain attached to the alternative, given
-- that they are generated by the corresponding expression.
if Present (Sinfo.Actions (Alt)) then
Prepend_List (Sinfo.Actions (Alt), Stats);
end if;
Append_To
(Alternatives (Cstmt),
Make_Case_Statement_Alternative (Sloc (Alt),
Discrete_Choices => Discrete_Choices (Alt),
Statements => Stats));
end;
Next (Alt);
end loop;
Append_To (Actions, Cstmt);
-- Construct and return final expression with actions
if Is_Elementary_Type (Typ) then
Fexp := New_Occurrence_Of (Tnn, Loc);
else
Fexp :=
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Tnn, Loc));
end if;
Rewrite (N,
Make_Expression_With_Actions (Loc,
Expression => Fexp,
Actions => Actions));
Analyze_And_Resolve (N, Typ);
end Expand_N_Case_Expression;
-----------------------------------
-- Expand_N_Explicit_Dereference --
-----------------------------------
procedure Expand_N_Explicit_Dereference (N : Node_Id) is
begin
-- Insert explicit dereference call for the checked storage pool case
Insert_Dereference_Action (Prefix (N));
-- If the type is an Atomic type for which Atomic_Sync is enabled, then
-- we set the atomic sync flag.
if Is_Atomic (Etype (N))
and then not Atomic_Synchronization_Disabled (Etype (N))
then
Activate_Atomic_Synchronization (N);
end if;
end Expand_N_Explicit_Dereference;
--------------------------------------
-- Expand_N_Expression_With_Actions --
--------------------------------------
procedure Expand_N_Expression_With_Actions (N : Node_Id) is
In_Case_Or_If_Expression : constant Boolean :=
Within_Case_Or_If_Expression (N);
function Process_Action (Act : Node_Id) return Traverse_Result;
-- Inspect and process a single action of an expression_with_actions
--------------------
-- Process_Action --
--------------------
function Process_Action (Act : Node_Id) return Traverse_Result is
procedure Process_Transient_Object (Obj_Decl : Node_Id);
-- Obj_Decl denotes the declaration of a transient controlled object.
-- Generate all necessary types and hooks to properly finalize the
-- result when the enclosing context is elaborated/evaluated.
------------------------------
-- Process_Transient_Object --
------------------------------
procedure Process_Transient_Object (Obj_Decl : Node_Id) is
function Find_Enclosing_Context return Node_Id;
-- Find the context where the expression_with_actions appears
----------------------------
-- Find_Enclosing_Context --
----------------------------
function Find_Enclosing_Context return Node_Id is
function Is_Body_Or_Unit (N : Node_Id) return Boolean;
-- Determine whether N denotes a body or unit declaration
---------------------
-- Is_Body_Or_Unit --
---------------------
function Is_Body_Or_Unit (N : Node_Id) return Boolean is
begin
return Nkind_In (N, N_Entry_Body,
N_Package_Body,
N_Package_Declaration,
N_Protected_Body,
N_Subprogram_Body,
N_Task_Body);
end Is_Body_Or_Unit;
-- Local variables
Par : Node_Id;
Top : Node_Id;
-- Start of processing for Find_Enclosing_Context
begin
-- The expression_with_actions is in a case/if expression and
-- the lifetime of any temporary controlled object is therefore
-- extended. Find a suitable insertion node by locating the top
-- most case or if expressions.
if In_Case_Or_If_Expression then
Par := N;
Top := N;
while Present (Par) loop
if Nkind_In (Original_Node (Par), N_Case_Expression,
N_If_Expression)
then
Top := Par;
-- Prevent the search from going too far
elsif Is_Body_Or_Unit (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
-- The topmost case or if expression is now recovered, but
-- it may still not be the correct place to add all the
-- generated code. Climb to find a parent that is part of a
-- declarative or statement list.
Par := Top;
while Present (Par) loop
if Is_List_Member (Par)
and then
not Nkind_In (Par, N_Component_Association,
N_Discriminant_Association,
N_Parameter_Association,
N_Pragma_Argument_Association)
then
return Par;
-- Prevent the search from going too far
elsif Is_Body_Or_Unit (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
return Par;
-- Short circuit operators in complex expressions are converted
-- into expression_with_actions.
else
-- Take care of the case where the expression_with_actions
-- is buried deep inside an IF statement. The temporary
-- function result must be finalized before the then, elsif
-- or else statements are evaluated.
-- if Something
-- and then Ctrl_Func_Call
-- then
-- <result must be finalized at this point>
-- <statements>
-- end if;
-- To achieve this, find the topmost logical operator. The
-- generated actions are then inserted before/after it.
Par := N;
while Present (Par) loop
-- Keep climbing past various operators
if Nkind (Parent (Par)) in N_Op
or else Nkind_In (Parent (Par), N_And_Then, N_Or_Else)
then
Par := Parent (Par);
else
exit;
end if;
end loop;
Top := Par;
-- The expression_with_actions might be located in a pragma
-- in which case locate the pragma itself:
-- pragma Precondition (... and then Ctrl_Func_Call ...);
-- Similar case occurs when the expression_with_actions is
-- related to an object declaration or assignment:
-- Obj [: Some_Typ] := ... and then Ctrl_Func_Call ...;
-- Another case to consider is an expression_with_actions as
-- part of a return statement:
-- return ... and then Ctrl_Func_Call ...;
while Present (Par) loop
if Nkind_In (Par, N_Assignment_Statement,
N_Object_Declaration,
N_Pragma,
N_Simple_Return_Statement)
then
return Par;
elsif Is_Body_Or_Unit (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
-- Return the topmost short circuit operator
return Top;
end if;
end Find_Enclosing_Context;
-- Local variables
Context : constant Node_Id := Find_Enclosing_Context;
Loc : constant Source_Ptr := Sloc (Obj_Decl);
Obj_Id : constant Entity_Id := Defining_Identifier (Obj_Decl);
Obj_Typ : constant Node_Id := Etype (Obj_Id);
Desig_Typ : Entity_Id;
Expr : Node_Id;
Ptr_Id : Entity_Id;
Temp_Id : Entity_Id;
-- Start of processing for Process_Transient_Object
begin
-- Step 1: Create the access type which provides a reference to
-- the transient object.
if Is_Access_Type (Obj_Typ) then
Desig_Typ := Directly_Designated_Type (Obj_Typ);
else
Desig_Typ := Obj_Typ;
end if;
-- Generate:
-- Ann : access [all] <Desig_Typ>;
Ptr_Id := Make_Temporary (Loc, 'A');
Insert_Action (Context,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ptr_Id,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present =>
Ekind (Obj_Typ) = E_General_Access_Type,
Subtype_Indication => New_Reference_To (Desig_Typ, Loc))));
-- Step 2: Create a temporary which acts as a hook to the
-- transient object. Generate:
-- Temp : Ptr_Id := null;
Temp_Id := Make_Temporary (Loc, 'T');
Insert_Action (Context,
Make_Object_Declaration (Loc,
Defining_Identifier => Temp_Id,
Object_Definition => New_Reference_To (Ptr_Id, Loc)));
-- Mark this temporary as created for the purposes of exporting
-- the transient declaration out of the Actions list. This signals
-- the machinery in Build_Finalizer to recognize this special
-- case.
Set_Status_Flag_Or_Transient_Decl (Temp_Id, Obj_Decl);
-- Step 3: Hook the transient object to the temporary
if Is_Access_Type (Obj_Typ) then
Expr := Convert_To (Ptr_Id, New_Reference_To (Obj_Id, Loc));
else
Expr :=
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Obj_Id, Loc),
Attribute_Name => Name_Unrestricted_Access);
end if;
-- Generate:
-- Temp := Ptr_Id (Obj_Id);
-- <or>
-- Temp := Obj_Id'Unrestricted_Access;
Insert_After_And_Analyze (Obj_Decl,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Temp_Id, Loc),
Expression => Expr));
-- Step 4: Finalize the function result after the context has been
-- evaluated/elaborated. Generate:
-- if Temp /= null then
-- [Deep_]Finalize (Temp.all);
-- Temp := null;
-- end if;
-- When the expression_with_actions is part of a return statement,
-- there is no need to insert a finalization call, as the general
-- finalization mechanism (see Build_Finalizer) would take care of
-- the temporary function result on subprogram exit. Note that it
-- would also be impossible to insert the finalization code after
-- the return statement as this would make it unreachable.
if Nkind (Context) /= N_Simple_Return_Statement then
Insert_Action_After (Context,
Make_If_Statement (Loc,
Condition =>
Make_Op_Ne (Loc,
Left_Opnd => New_Reference_To (Temp_Id, Loc),
Right_Opnd => Make_Null (Loc)),
Then_Statements => New_List (
Make_Final_Call
(Obj_Ref =>
Make_Explicit_Dereference (Loc,
Prefix => New_Reference_To (Temp_Id, Loc)),
Typ => Desig_Typ),
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Temp_Id, Loc),
Expression => Make_Null (Loc)))));
end if;
end Process_Transient_Object;
-- Start of processing for Process_Action
begin
if Nkind (Act) = N_Object_Declaration
and then Is_Finalizable_Transient (Act, N)
then
Process_Transient_Object (Act);
-- Avoid processing temporary function results multiple times when
-- dealing with nested expression_with_actions.
elsif Nkind (Act) = N_Expression_With_Actions then
return Abandon;
-- Do not process temporary function results in loops. This is
-- done by Expand_N_Loop_Statement and Build_Finalizer.
elsif Nkind (Act) = N_Loop_Statement then
return Abandon;
end if;
return OK;
end Process_Action;
procedure Process_Single_Action is new Traverse_Proc (Process_Action);
-- Local variables
Act : Node_Id;
-- Start of processing for Expand_N_Expression_With_Actions
begin
Act := First (Actions (N));
while Present (Act) loop
Process_Single_Action (Act);
Next (Act);
end loop;
end Expand_N_Expression_With_Actions;
----------------------------
-- Expand_N_If_Expression --
----------------------------
-- Deal with limited types and condition actions
procedure Expand_N_If_Expression (N : Node_Id) is
function Create_Alternative
(Loc : Source_Ptr;
Temp_Id : Entity_Id;
Flag_Id : Entity_Id;
Expr : Node_Id) return List_Id;
-- Build the statements of a "then" or "else" dependent expression
-- alternative. Temp_Id is the if expression result, Flag_Id is a
-- finalization flag created to service expression Expr.
function Is_Controlled_Function_Call (Expr : Node_Id) return Boolean;
-- Determine if expression Expr is a rewritten controlled function call
------------------------
-- Create_Alternative --
------------------------
function Create_Alternative
(Loc : Source_Ptr;
Temp_Id : Entity_Id;
Flag_Id : Entity_Id;
Expr : Node_Id) return List_Id
is
Result : constant List_Id := New_List;
begin
-- Generate:
-- Fnn := True;
if Present (Flag_Id)
and then not Is_Controlled_Function_Call (Expr)
then
Append_To (Result,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Flag_Id, Loc),
Expression => New_Reference_To (Standard_True, Loc)));
end if;
-- Generate:
-- Cnn := <expr>'Unrestricted_Access;
Append_To (Result,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Temp_Id, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Expr),
Attribute_Name => Name_Unrestricted_Access)));
return Result;
end Create_Alternative;
---------------------------------
-- Is_Controlled_Function_Call --
---------------------------------
function Is_Controlled_Function_Call (Expr : Node_Id) return Boolean is
begin
return
Nkind (Original_Node (Expr)) = N_Function_Call
and then Needs_Finalization (Etype (Expr));
end Is_Controlled_Function_Call;
-- Local variables
Loc : constant Source_Ptr := Sloc (N);
Cond : constant Node_Id := First (Expressions (N));
Thenx : constant Node_Id := Next (Cond);
Elsex : constant Node_Id := Next (Thenx);
Typ : constant Entity_Id := Etype (N);
Actions : List_Id;
Cnn : Entity_Id;
Decl : Node_Id;
Expr : Node_Id;
New_If : Node_Id;
New_N : Node_Id;
-- Start of processing for Expand_N_If_Expression
begin
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- Fold at compile time if condition known. We have already folded
-- static if expressions, but it is possible to fold any case in which
-- the condition is known at compile time, even though the result is
-- non-static.
-- Note that we don't do the fold of such cases in Sem_Elab because
-- it can cause infinite loops with the expander adding a conditional
-- expression, and Sem_Elab circuitry removing it repeatedly.
if Compile_Time_Known_Value (Cond) then
if Is_True (Expr_Value (Cond)) then
Expr := Thenx;
Actions := Then_Actions (N);
else
Expr := Elsex;
Actions := Else_Actions (N);
end if;
Remove (Expr);
if Present (Actions) then
-- If we are not allowed to use Expression_With_Actions, just skip
-- the optimization, it is not critical for correctness.
if not Use_Expression_With_Actions then
goto Skip_Optimization;
end if;
Rewrite (N,
Make_Expression_With_Actions (Loc,
Expression => Relocate_Node (Expr),
Actions => Actions));
Analyze_And_Resolve (N, Typ);
else
Rewrite (N, Relocate_Node (Expr));
end if;
-- Note that the result is never static (legitimate cases of static
-- if expressions were folded in Sem_Eval).
Set_Is_Static_Expression (N, False);
return;
end if;
<<Skip_Optimization>>
-- If the type is limited or unconstrained, we expand as follows to
-- avoid any possibility of improper copies.
-- Note: it may be possible to avoid this special processing if the
-- back end uses its own mechanisms for handling by-reference types ???
-- type Ptr is access all Typ;
-- Cnn : Ptr;
-- if cond then
-- <<then actions>>
-- Cnn := then-expr'Unrestricted_Access;
-- else
-- <<else actions>>
-- Cnn := else-expr'Unrestricted_Access;
-- end if;
-- and replace the if expression by a reference to Cnn.all.
-- This special case can be skipped if the back end handles limited
-- types properly and ensures that no incorrect copies are made.
if Is_By_Reference_Type (Typ)
and then not Back_End_Handles_Limited_Types
then
declare
Flag_Id : Entity_Id;
Ptr_Typ : Entity_Id;
begin
Flag_Id := Empty;
-- At least one of the if expression dependent expressions uses a
-- controlled function to provide the result. Create a status flag
-- to signal the finalization machinery that Cnn needs special
-- handling.
if Is_Controlled_Function_Call (Thenx)
or else
Is_Controlled_Function_Call (Elsex)
then
Flag_Id := Make_Temporary (Loc, 'F');
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Flag_Id,
Object_Definition =>
New_Reference_To (Standard_Boolean, Loc),
Expression =>
New_Reference_To (Standard_False, Loc)));
end if;
-- Generate:
-- type Ann is access all Typ;
Ptr_Typ := Make_Temporary (Loc, 'A');
Insert_Action (N,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ptr_Typ,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication => New_Reference_To (Typ, Loc))));
-- Generate:
-- Cnn : Ann;
Cnn := Make_Temporary (Loc, 'C', N);
Set_Ekind (Cnn, E_Variable);
Set_Status_Flag_Or_Transient_Decl (Cnn, Flag_Id);
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Cnn,
Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc));
New_If :=
Make_Implicit_If_Statement (N,
Condition => Relocate_Node (Cond),
Then_Statements =>
Create_Alternative (Sloc (Thenx), Cnn, Flag_Id, Thenx),
Else_Statements =>
Create_Alternative (Sloc (Elsex), Cnn, Flag_Id, Elsex));
New_N :=
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Cnn, Loc));
end;
-- For other types, we only need to expand if there are other actions
-- associated with either branch.
elsif Present (Then_Actions (N)) or else Present (Else_Actions (N)) then
-- We have two approaches to handling this. If we are allowed to use
-- N_Expression_With_Actions, then we can just wrap the actions into
-- the appropriate expression.
if Use_Expression_With_Actions then
if Present (Then_Actions (N)) then
Rewrite (Thenx,
Make_Expression_With_Actions (Sloc (Thenx),
Actions => Then_Actions (N),
Expression => Relocate_Node (Thenx)));
Set_Then_Actions (N, No_List);
Analyze_And_Resolve (Thenx, Typ);
end if;
if Present (Else_Actions (N)) then
Rewrite (Elsex,
Make_Expression_With_Actions (Sloc (Elsex),
Actions => Else_Actions (N),
Expression => Relocate_Node (Elsex)));
Set_Else_Actions (N, No_List);
Analyze_And_Resolve (Elsex, Typ);
end if;
return;
-- if we can't use N_Expression_With_Actions nodes, then we insert
-- the following sequence of actions (using Insert_Actions):
-- Cnn : typ;
-- if cond then
-- <<then actions>>
-- Cnn := then-expr;
-- else
-- <<else actions>>
-- Cnn := else-expr
-- end if;
-- and replace the if expression by a reference to Cnn
else
Cnn := Make_Temporary (Loc, 'C', N);
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Cnn,
Object_Definition => New_Occurrence_Of (Typ, Loc));
New_If :=
Make_Implicit_If_Statement (N,
Condition => Relocate_Node (Cond),
Then_Statements => New_List (
Make_Assignment_Statement (Sloc (Thenx),
Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
Expression => Relocate_Node (Thenx))),
Else_Statements => New_List (
Make_Assignment_Statement (Sloc (Elsex),
Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
Expression => Relocate_Node (Elsex))));
Set_Assignment_OK (Name (First (Then_Statements (New_If))));
Set_Assignment_OK (Name (First (Else_Statements (New_If))));
New_N := New_Occurrence_Of (Cnn, Loc);
end if;
-- If no actions then no expansion needed, gigi will handle it using
-- the same approach as a C conditional expression.
else
return;
end if;
-- Fall through here for either the limited expansion, or the case of
-- inserting actions for non-limited types. In both these cases, we must
-- move the SLOC of the parent If statement to the newly created one and
-- change it to the SLOC of the expression which, after expansion, will
-- correspond to what is being evaluated.
if Present (Parent (N))
and then Nkind (Parent (N)) = N_If_Statement
then
Set_Sloc (New_If, Sloc (Parent (N)));
Set_Sloc (Parent (N), Loc);
end if;
-- Make sure Then_Actions and Else_Actions are appropriately moved
-- to the new if statement.
if Present (Then_Actions (N)) then
Insert_List_Before
(First (Then_Statements (New_If)), Then_Actions (N));
end if;
if Present (Else_Actions (N)) then
Insert_List_Before
(First (Else_Statements (New_If)), Else_Actions (N));
end if;
Insert_Action (N, Decl);
Insert_Action (N, New_If);
Rewrite (N, New_N);
Analyze_And_Resolve (N, Typ);
end Expand_N_If_Expression;
-----------------
-- Expand_N_In --
-----------------
procedure Expand_N_In (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Restyp : constant Entity_Id := Etype (N);
Lop : constant Node_Id := Left_Opnd (N);
Rop : constant Node_Id := Right_Opnd (N);
Static : constant Boolean := Is_OK_Static_Expression (N);
Ltyp : Entity_Id;
Rtyp : Entity_Id;
procedure Substitute_Valid_Check;
-- Replaces node N by Lop'Valid. This is done when we have an explicit
-- test for the left operand being in range of its subtype.
----------------------------
-- Substitute_Valid_Check --
----------------------------
procedure Substitute_Valid_Check is
begin
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Lop),
Attribute_Name => Name_Valid));
Analyze_And_Resolve (N, Restyp);
-- Give warning unless overflow checking is MINIMIZED or ELIMINATED,
-- in which case, this usage makes sense, and in any case, we have
-- actually eliminated the danger of optimization above.
if Overflow_Check_Mode not in Minimized_Or_Eliminated then
Error_Msg_N
("??explicit membership test may be optimized away", N);
Error_Msg_N -- CODEFIX
("\??use ''Valid attribute instead", N);
end if;
return;
end Substitute_Valid_Check;
-- Start of processing for Expand_N_In
begin
-- If set membership case, expand with separate procedure
if Present (Alternatives (N)) then
Expand_Set_Membership (N);
return;
end if;
-- Not set membership, proceed with expansion
Ltyp := Etype (Left_Opnd (N));
Rtyp := Etype (Right_Opnd (N));
-- If MINIMIZED/ELIMINATED overflow mode and type is a signed integer
-- type, then expand with a separate procedure. Note the use of the
-- flag No_Minimize_Eliminate to prevent infinite recursion.
if Overflow_Check_Mode in Minimized_Or_Eliminated
and then Is_Signed_Integer_Type (Ltyp)
and then not No_Minimize_Eliminate (N)
then
Expand_Membership_Minimize_Eliminate_Overflow (N);
return;
end if;
-- Check case of explicit test for an expression in range of its
-- subtype. This is suspicious usage and we replace it with a 'Valid
-- test and give a warning for scalar types.
if Is_Scalar_Type (Ltyp)
-- Only relevant for source comparisons
and then Comes_From_Source (N)
-- In floating-point this is a standard way to check for finite values
-- and using 'Valid would typically be a pessimization.
and then not Is_Floating_Point_Type (Ltyp)
-- Don't give the message unless right operand is a type entity and
-- the type of the left operand matches this type. Note that this
-- eliminates the cases where MINIMIZED/ELIMINATED mode overflow
-- checks have changed the type of the left operand.
and then Nkind (Rop) in N_Has_Entity
and then Ltyp = Entity (Rop)
-- Skip in VM mode, where we have no sense of invalid values. The
-- warning still seems relevant, but not important enough to worry.
and then VM_Target = No_VM
-- Skip this for predicated types, where such expressions are a
-- reasonable way of testing if something meets the predicate.
and then not Present (Predicate_Function (Ltyp))
then
Substitute_Valid_Check;
return;
end if;
-- Do validity check on operands
if Validity_Checks_On and Validity_Check_Operands then
Ensure_Valid (Left_Opnd (N));
Validity_Check_Range (Right_Opnd (N));
end if;
-- Case of explicit range
if Nkind (Rop) = N_Range then
declare
Lo : constant Node_Id := Low_Bound (Rop);
Hi : constant Node_Id := High_Bound (Rop);
Lo_Orig : constant Node_Id := Original_Node (Lo);
Hi_Orig : constant Node_Id := Original_Node (Hi);
Lcheck : Compare_Result;
Ucheck : Compare_Result;
Warn1 : constant Boolean :=
Constant_Condition_Warnings
and then Comes_From_Source (N)
and then not In_Instance;
-- This must be true for any of the optimization warnings, we
-- clearly want to give them only for source with the flag on. We
-- also skip these warnings in an instance since it may be the
-- case that different instantiations have different ranges.
Warn2 : constant Boolean :=
Warn1
and then Nkind (Original_Node (Rop)) = N_Range
and then Is_Integer_Type (Etype (Lo));
-- For the case where only one bound warning is elided, we also
-- insist on an explicit range and an integer type. The reason is
-- that the use of enumeration ranges including an end point is
-- common, as is the use of a subtype name, one of whose bounds is
-- the same as the type of the expression.
begin
-- If test is explicit x'First .. x'Last, replace by valid check
-- Could use some individual comments for this complex test ???
if Is_Scalar_Type (Ltyp)
-- And left operand is X'First where X matches left operand
-- type (this eliminates cases of type mismatch, including
-- the cases where ELIMINATED/MINIMIZED mode has changed the
-- type of the left operand.
and then Nkind (Lo_Orig) = N_Attribute_Reference
and then Attribute_Name (Lo_Orig) = Name_First
and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity
and then Entity (Prefix (Lo_Orig)) = Ltyp
-- Same tests for right operand
and then Nkind (Hi_Orig) = N_Attribute_Reference
and then Attribute_Name (Hi_Orig) = Name_Last
and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity
and then Entity (Prefix (Hi_Orig)) = Ltyp
-- Relevant only for source cases
and then Comes_From_Source (N)
-- Omit for VM cases, where we don't have invalid values
and then VM_Target = No_VM
then
Substitute_Valid_Check;
goto Leave;
end if;
-- If bounds of type are known at compile time, and the end points
-- are known at compile time and identical, this is another case
-- for substituting a valid test. We only do this for discrete
-- types, since it won't arise in practice for float types.
if Comes_From_Source (N)
and then Is_Discrete_Type (Ltyp)
and then Compile_Time_Known_Value (Type_High_Bound (Ltyp))
and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp))
and then Compile_Time_Known_Value (Lo)
and then Compile_Time_Known_Value (Hi)
and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi)
and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo)
-- Kill warnings in instances, since they may be cases where we
-- have a test in the generic that makes sense with some types
-- and not with other types.
and then not In_Instance
then
Substitute_Valid_Check;
goto Leave;
end if;
-- If we have an explicit range, do a bit of optimization based on
-- range analysis (we may be able to kill one or both checks).
Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False);
Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False);
-- If either check is known to fail, replace result by False since
-- the other check does not matter. Preserve the static flag for
-- legality checks, because we are constant-folding beyond RM 4.9.
if Lcheck = LT or else Ucheck = GT then
if Warn1 then
Error_Msg_N ("?c?range test optimized away", N);
Error_Msg_N ("\?c?value is known to be out of range", N);
end if;
Rewrite (N, New_Reference_To (Standard_False, Loc));
Analyze_And_Resolve (N, Restyp);
Set_Is_Static_Expression (N, Static);
goto Leave;
-- If both checks are known to succeed, replace result by True,
-- since we know we are in range.
elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
if Warn1 then
Error_Msg_N ("?c?range test optimized away", N);
Error_Msg_N ("\?c?value is known to be in range", N);
end if;
Rewrite (N, New_Reference_To (Standard_True, Loc));
Analyze_And_Resolve (N, Restyp);
Set_Is_Static_Expression (N, Static);
goto Leave;
-- If lower bound check succeeds and upper bound check is not
-- known to succeed or fail, then replace the range check with
-- a comparison against the upper bound.
elsif Lcheck in Compare_GE then
if Warn2 and then not In_Instance then
Error_Msg_N ("??lower bound test optimized away", Lo);
Error_Msg_N ("\??value is known to be in range", Lo);
end if;
Rewrite (N,
Make_Op_Le (Loc,
Left_Opnd => Lop,
Right_Opnd => High_Bound (Rop)));
Analyze_And_Resolve (N, Restyp);
goto Leave;
-- If upper bound check succeeds and lower bound check is not
-- known to succeed or fail, then replace the range check with
-- a comparison against the lower bound.
elsif Ucheck in Compare_LE then
if Warn2 and then not In_Instance then
Error_Msg_N ("??upper bound test optimized away", Hi);
Error_Msg_N ("\??value is known to be in range", Hi);
end if;
Rewrite (N,
Make_Op_Ge (Loc,
Left_Opnd => Lop,
Right_Opnd => Low_Bound (Rop)));
Analyze_And_Resolve (N, Restyp);
goto Leave;
end if;
-- We couldn't optimize away the range check, but there is one
-- more issue. If we are checking constant conditionals, then we
-- see if we can determine the outcome assuming everything is
-- valid, and if so give an appropriate warning.
if Warn1 and then not Assume_No_Invalid_Values then
Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True);
Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True);
-- Result is out of range for valid value
if Lcheck = LT or else Ucheck = GT then
Error_Msg_N
("?c?value can only be in range if it is invalid", N);
-- Result is in range for valid value
elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
Error_Msg_N
("?c?value can only be out of range if it is invalid", N);
-- Lower bound check succeeds if value is valid
elsif Warn2 and then Lcheck in Compare_GE then
Error_Msg_N
("?c?lower bound check only fails if it is invalid", Lo);
-- Upper bound check succeeds if value is valid
elsif Warn2 and then Ucheck in Compare_LE then
Error_Msg_N
("?c?upper bound check only fails for invalid values", Hi);
end if;
end if;
end;
-- For all other cases of an explicit range, nothing to be done
goto Leave;
-- Here right operand is a subtype mark
else
declare
Typ : Entity_Id := Etype (Rop);
Is_Acc : constant Boolean := Is_Access_Type (Typ);
Cond : Node_Id := Empty;
New_N : Node_Id;
Obj : Node_Id := Lop;
SCIL_Node : Node_Id;
begin
Remove_Side_Effects (Obj);
-- For tagged type, do tagged membership operation
if Is_Tagged_Type (Typ) then
-- No expansion will be performed when VM_Target, as the VM
-- back-ends will handle the membership tests directly (tags
-- are not explicitly represented in Java objects, so the
-- normal tagged membership expansion is not what we want).
if Tagged_Type_Expansion then
Tagged_Membership (N, SCIL_Node, New_N);
Rewrite (N, New_N);
Analyze_And_Resolve (N, Restyp);
-- Update decoration of relocated node referenced by the
-- SCIL node.
if Generate_SCIL and then Present (SCIL_Node) then
Set_SCIL_Node (N, SCIL_Node);
end if;
end if;
goto Leave;
-- If type is scalar type, rewrite as x in t'First .. t'Last.
-- This reason we do this is that the bounds may have the wrong
-- type if they come from the original type definition. Also this
-- way we get all the processing above for an explicit range.
-- Don't do this for predicated types, since in this case we
-- want to check the predicate!
elsif Is_Scalar_Type (Typ) then
if No (Predicate_Function (Typ)) then
Rewrite (Rop,
Make_Range (Loc,
Low_Bound =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Reference_To (Typ, Loc)),
High_Bound =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Reference_To (Typ, Loc))));
Analyze_And_Resolve (N, Restyp);
end if;
goto Leave;
-- Ada 2005 (AI-216): Program_Error is raised when evaluating
-- a membership test if the subtype mark denotes a constrained
-- Unchecked_Union subtype and the expression lacks inferable
-- discriminants.
elsif Is_Unchecked_Union (Base_Type (Typ))
and then Is_Constrained (Typ)
and then not Has_Inferable_Discriminants (Lop)
then
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
-- Prevent Gigi from generating incorrect code by rewriting the
-- test as False. What is this undocumented thing about ???
Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
goto Leave;
end if;
-- Here we have a non-scalar type
if Is_Acc then
Typ := Designated_Type (Typ);
end if;
if not Is_Constrained (Typ) then
Rewrite (N, New_Reference_To (Standard_True, Loc));
Analyze_And_Resolve (N, Restyp);
-- For the constrained array case, we have to check the subscripts
-- for an exact match if the lengths are non-zero (the lengths
-- must match in any case).
elsif Is_Array_Type (Typ) then
Check_Subscripts : declare
function Build_Attribute_Reference
(E : Node_Id;
Nam : Name_Id;
Dim : Nat) return Node_Id;
-- Build attribute reference E'Nam (Dim)
-------------------------------
-- Build_Attribute_Reference --
-------------------------------
function Build_Attribute_Reference
(E : Node_Id;
Nam : Name_Id;
Dim : Nat) return Node_Id
is
begin
return
Make_Attribute_Reference (Loc,
Prefix => E,
Attribute_Name => Nam,
Expressions => New_List (
Make_Integer_Literal (Loc, Dim)));
end Build_Attribute_Reference;
-- Start of processing for Check_Subscripts
begin
for J in 1 .. Number_Dimensions (Typ) loop
Evolve_And_Then (Cond,
Make_Op_Eq (Loc,
Left_Opnd =>
Build_Attribute_Reference
(Duplicate_Subexpr_No_Checks (Obj),
Name_First, J),
Right_Opnd =>
Build_Attribute_Reference
(New_Occurrence_Of (Typ, Loc), Name_First, J)));
Evolve_And_Then (Cond,
Make_Op_Eq (Loc,
Left_Opnd =>
Build_Attribute_Reference
(Duplicate_Subexpr_No_Checks (Obj),
Name_Last, J),
Right_Opnd =>
Build_Attribute_Reference
(New_Occurrence_Of (Typ, Loc), Name_Last, J)));
end loop;
if Is_Acc then
Cond :=
Make_Or_Else (Loc,
Left_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => Obj,
Right_Opnd => Make_Null (Loc)),
Right_Opnd => Cond);
end if;
Rewrite (N, Cond);
Analyze_And_Resolve (N, Restyp);
end Check_Subscripts;
-- These are the cases where constraint checks may be required,
-- e.g. records with possible discriminants
else
-- Expand the test into a series of discriminant comparisons.
-- The expression that is built is the negation of the one that
-- is used for checking discriminant constraints.
Obj := Relocate_Node (Left_Opnd (N));
if Has_Discriminants (Typ) then
Cond := Make_Op_Not (Loc,
Right_Opnd => Build_Discriminant_Checks (Obj, Typ));
if Is_Acc then
Cond := Make_Or_Else (Loc,
Left_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => Obj,
Right_Opnd => Make_Null (Loc)),
Right_Opnd => Cond);
end if;
else
Cond := New_Occurrence_Of (Standard_True, Loc);
end if;
Rewrite (N, Cond);
Analyze_And_Resolve (N, Restyp);
end if;
-- Ada 2012 (AI05-0149): Handle membership tests applied to an
-- expression of an anonymous access type. This can involve an
-- accessibility test and a tagged type membership test in the
-- case of tagged designated types.
if Ada_Version >= Ada_2012
and then Is_Acc
and then Ekind (Ltyp) = E_Anonymous_Access_Type
then
declare
Expr_Entity : Entity_Id := Empty;
New_N : Node_Id;
Param_Level : Node_Id;
Type_Level : Node_Id;
begin
if Is_Entity_Name (Lop) then
Expr_Entity := Param_Entity (Lop);
if not Present (Expr_Entity) then
Expr_Entity := Entity (Lop);
end if;
end if;
-- If a conversion of the anonymous access value to the
-- tested type would be illegal, then the result is False.
if not Valid_Conversion
(Lop, Rtyp, Lop, Report_Errs => False)
then
Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
Analyze_And_Resolve (N, Restyp);
-- Apply an accessibility check if the access object has an
-- associated access level and when the level of the type is
-- less deep than the level of the access parameter. This
-- only occur for access parameters and stand-alone objects
-- of an anonymous access type.
else
if Present (Expr_Entity)
and then
Present
(Effective_Extra_Accessibility (Expr_Entity))
and then UI_Gt (Object_Access_Level (Lop),
Type_Access_Level (Rtyp))
then
Param_Level :=
New_Occurrence_Of
(Effective_Extra_Accessibility (Expr_Entity), Loc);
Type_Level :=
Make_Integer_Literal (Loc, Type_Access_Level (Rtyp));
-- Return True only if the accessibility level of the
-- expression entity is not deeper than the level of
-- the tested access type.
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd => Relocate_Node (N),
Right_Opnd => Make_Op_Le (Loc,
Left_Opnd => Param_Level,
Right_Opnd => Type_Level)));
Analyze_And_Resolve (N);
end if;
-- If the designated type is tagged, do tagged membership
-- operation.
-- *** NOTE: we have to check not null before doing the
-- tagged membership test (but maybe that can be done
-- inside Tagged_Membership?).
if Is_Tagged_Type (Typ) then
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd => Relocate_Node (N),
Right_Opnd =>
Make_Op_Ne (Loc,
Left_Opnd => Obj,
Right_Opnd => Make_Null (Loc))));
-- No expansion will be performed when VM_Target, as
-- the VM back-ends will handle the membership tests
-- directly (tags are not explicitly represented in
-- Java objects, so the normal tagged membership
-- expansion is not what we want).
if Tagged_Type_Expansion then
-- Note that we have to pass Original_Node, because
-- the membership test might already have been
-- rewritten by earlier parts of membership test.
Tagged_Membership
(Original_Node (N), SCIL_Node, New_N);
-- Update decoration of relocated node referenced
-- by the SCIL node.
if Generate_SCIL and then Present (SCIL_Node) then
Set_SCIL_Node (New_N, SCIL_Node);
end if;
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd => Relocate_Node (N),
Right_Opnd => New_N));
Analyze_And_Resolve (N, Restyp);
end if;
end if;
end if;
end;
end if;
end;
end if;
-- At this point, we have done the processing required for the basic
-- membership test, but not yet dealt with the predicate.
<<Leave>>
-- If a predicate is present, then we do the predicate test, but we
-- most certainly want to omit this if we are within the predicate
-- function itself, since otherwise we have an infinite recursion!
-- The check should also not be emitted when testing against a range
-- (the check is only done when the right operand is a subtype; see
-- RM12-4.5.2 (28.1/3-30/3)).
declare
PFunc : constant Entity_Id := Predicate_Function (Rtyp);
begin
if Present (PFunc)
and then Current_Scope /= PFunc
and then Nkind (Rop) /= N_Range
then
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd => Relocate_Node (N),
Right_Opnd => Make_Predicate_Call (Rtyp, Lop)));
-- Analyze new expression, mark left operand as analyzed to
-- avoid infinite recursion adding predicate calls. Similarly,
-- suppress further range checks on the call.
Set_Analyzed (Left_Opnd (N));
Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
-- All done, skip attempt at compile time determination of result
return;
end if;
end;
end Expand_N_In;
--------------------------------
-- Expand_N_Indexed_Component --
--------------------------------
procedure Expand_N_Indexed_Component (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
P : constant Node_Id := Prefix (N);
T : constant Entity_Id := Etype (P);
Atp : Entity_Id;
begin
-- A special optimization, if we have an indexed component that is
-- selecting from a slice, then we can eliminate the slice, since, for
-- example, x (i .. j)(k) is identical to x(k). The only difference is
-- the range check required by the slice. The range check for the slice
-- itself has already been generated. The range check for the
-- subscripting operation is ensured by converting the subject to
-- the subtype of the slice.
-- This optimization not only generates better code, avoiding slice
-- messing especially in the packed case, but more importantly bypasses
-- some problems in handling this peculiar case, for example, the issue
-- of dealing specially with object renamings.
if Nkind (P) = N_Slice then
Rewrite (N,
Make_Indexed_Component (Loc,
Prefix => Prefix (P),
Expressions => New_List (
Convert_To
(Etype (First_Index (Etype (P))),
First (Expressions (N))))));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
-- function, then additional actuals must be passed.
if Ada_Version >= Ada_2005
and then Is_Build_In_Place_Function_Call (P)
then
Make_Build_In_Place_Call_In_Anonymous_Context (P);
end if;
-- If the prefix is an access type, then we unconditionally rewrite if
-- as an explicit dereference. This simplifies processing for several
-- cases, including packed array cases and certain cases in which checks
-- must be generated. We used to try to do this only when it was
-- necessary, but it cleans up the code to do it all the time.
if Is_Access_Type (T) then
Insert_Explicit_Dereference (P);
Analyze_And_Resolve (P, Designated_Type (T));
Atp := Designated_Type (T);
else
Atp := T;
end if;
-- Generate index and validity checks
Generate_Index_Checks (N);
if Validity_Checks_On and then Validity_Check_Subscripts then
Apply_Subscript_Validity_Checks (N);
end if;
-- If selecting from an array with atomic components, and atomic sync
-- is not suppressed for this array type, set atomic sync flag.
if (Has_Atomic_Components (Atp)
and then not Atomic_Synchronization_Disabled (Atp))
or else (Is_Atomic (Typ)
and then not Atomic_Synchronization_Disabled (Typ))
then
Activate_Atomic_Synchronization (N);
end if;
-- All done for the non-packed case
if not Is_Packed (Etype (Prefix (N))) then
return;
end if;
-- For packed arrays that are not bit-packed (i.e. the case of an array
-- with one or more index types with a non-contiguous enumeration type),
-- we can always use the normal packed element get circuit.
if not Is_Bit_Packed_Array (Etype (Prefix (N))) then
Expand_Packed_Element_Reference (N);
return;
end if;
-- For a reference to a component of a bit packed array, we have to
-- convert it to a reference to the corresponding Packed_Array_Type.
-- We only want to do this for simple references, and not for:
-- Left side of assignment, or prefix of left side of assignment, or
-- prefix of the prefix, to handle packed arrays of packed arrays,
-- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
-- Renaming objects in renaming associations
-- This case is handled when a use of the renamed variable occurs
-- Actual parameters for a procedure call
-- This case is handled in Exp_Ch6.Expand_Actuals
-- The second expression in a 'Read attribute reference
-- The prefix of an address or bit or size attribute reference
-- The following circuit detects these exceptions
declare
Child : Node_Id := N;
Parnt : Node_Id := Parent (N);
begin
loop
if Nkind (Parnt) = N_Unchecked_Expression then
null;
elsif Nkind_In (Parnt, N_Object_Renaming_Declaration,
N_Procedure_Call_Statement)
or else (Nkind (Parnt) = N_Parameter_Association
and then
Nkind (Parent (Parnt)) = N_Procedure_Call_Statement)
then
return;
elsif Nkind (Parnt) = N_Attribute_Reference
and then (Attribute_Name (Parnt) = Name_Address
or else
Attribute_Name (Parnt) = Name_Bit
or else
Attribute_Name (Parnt) = Name_Size)
and then Prefix (Parnt) = Child
then
return;
elsif Nkind (Parnt) = N_Assignment_Statement
and then Name (Parnt) = Child
then
return;
-- If the expression is an index of an indexed component, it must
-- be expanded regardless of context.
elsif Nkind (Parnt) = N_Indexed_Component
and then Child /= Prefix (Parnt)
then
Expand_Packed_Element_Reference (N);
return;
elsif Nkind (Parent (Parnt)) = N_Assignment_Statement
and then Name (Parent (Parnt)) = Parnt
then
return;
elsif Nkind (Parnt) = N_Attribute_Reference
and then Attribute_Name (Parnt) = Name_Read
and then Next (First (Expressions (Parnt))) = Child
then
return;
elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component)
and then Prefix (Parnt) = Child
then
null;
else
Expand_Packed_Element_Reference (N);
return;
end if;
-- Keep looking up tree for unchecked expression, or if we are the
-- prefix of a possible assignment left side.
Child := Parnt;
Parnt := Parent (Child);
end loop;
end;
end Expand_N_Indexed_Component;
---------------------
-- Expand_N_Not_In --
---------------------
-- Replace a not in b by not (a in b) so that the expansions for (a in b)
-- can be done. This avoids needing to duplicate this expansion code.
procedure Expand_N_Not_In (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Cfs : constant Boolean := Comes_From_Source (N);
begin
Rewrite (N,
Make_Op_Not (Loc,
Right_Opnd =>
Make_In (Loc,
Left_Opnd => Left_Opnd (N),
Right_Opnd => Right_Opnd (N))));
-- If this is a set membership, preserve list of alternatives
Set_Alternatives (Right_Opnd (N), Alternatives (Original_Node (N)));
-- We want this to appear as coming from source if original does (see
-- transformations in Expand_N_In).
Set_Comes_From_Source (N, Cfs);
Set_Comes_From_Source (Right_Opnd (N), Cfs);
-- Now analyze transformed node
Analyze_And_Resolve (N, Typ);
end Expand_N_Not_In;
-------------------
-- Expand_N_Null --
-------------------
-- The only replacement required is for the case of a null of a type that
-- is an access to protected subprogram, or a subtype thereof. We represent
-- such access values as a record, and so we must replace the occurrence of
-- null by the equivalent record (with a null address and a null pointer in
-- it), so that the backend creates the proper value.
procedure Expand_N_Null (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Base_Type (Etype (N));
Agg : Node_Id;
begin
if Is_Access_Protected_Subprogram_Type (Typ) then
Agg :=
Make_Aggregate (Loc,
Expressions => New_List (
New_Occurrence_Of (RTE (RE_Null_Address), Loc),
Make_Null (Loc)));
Rewrite (N, Agg);
Analyze_And_Resolve (N, Equivalent_Type (Typ));
-- For subsequent semantic analysis, the node must retain its type.
-- Gigi in any case replaces this type by the corresponding record
-- type before processing the node.
Set_Etype (N, Typ);
end if;
exception
when RE_Not_Available =>
return;
end Expand_N_Null;
---------------------
-- Expand_N_Op_Abs --
---------------------
procedure Expand_N_Op_Abs (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Expr : constant Node_Id := Right_Opnd (N);
begin
Unary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- Deal with software overflow checking
if not Backend_Overflow_Checks_On_Target
and then Is_Signed_Integer_Type (Etype (N))
and then Do_Overflow_Check (N)
then
-- The only case to worry about is when the argument is equal to the
-- largest negative number, so what we do is to insert the check:
-- [constraint_error when Expr = typ'Base'First]
-- with the usual Duplicate_Subexpr use coding for expr
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd => Duplicate_Subexpr (Expr),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Base_Type (Etype (Expr)), Loc),
Attribute_Name => Name_First)),
Reason => CE_Overflow_Check_Failed));
end if;
-- Vax floating-point types case
if Vax_Float (Etype (N)) then
Expand_Vax_Arith (N);
end if;
end Expand_N_Op_Abs;
---------------------
-- Expand_N_Op_Add --
---------------------
procedure Expand_N_Op_Add (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
begin
Binary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- N + 0 = 0 + N = N for integer types
if Is_Integer_Type (Typ) then
if Compile_Time_Known_Value (Right_Opnd (N))
and then Expr_Value (Right_Opnd (N)) = Uint_0
then
Rewrite (N, Left_Opnd (N));
return;
elsif Compile_Time_Known_Value (Left_Opnd (N))
and then Expr_Value (Left_Opnd (N)) = Uint_0
then
Rewrite (N, Right_Opnd (N));
return;
end if;
end if;
-- Arithmetic overflow checks for signed integer/fixed point types
if Is_Signed_Integer_Type (Typ)
or else Is_Fixed_Point_Type (Typ)
then
Apply_Arithmetic_Overflow_Check (N);
return;
-- Vax floating-point types case
elsif Vax_Float (Typ) then
Expand_Vax_Arith (N);
end if;
end Expand_N_Op_Add;
---------------------
-- Expand_N_Op_And --
---------------------
procedure Expand_N_Op_And (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
begin
Binary_Op_Validity_Checks (N);
if Is_Array_Type (Etype (N)) then
Expand_Boolean_Operator (N);
elsif Is_Boolean_Type (Etype (N)) then
Adjust_Condition (Left_Opnd (N));
Adjust_Condition (Right_Opnd (N));
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
elsif Is_Intrinsic_Subprogram (Entity (N)) then
Expand_Intrinsic_Call (N, Entity (N));
end if;
end Expand_N_Op_And;
------------------------
-- Expand_N_Op_Concat --
------------------------
procedure Expand_N_Op_Concat (N : Node_Id) is
Opnds : List_Id;
-- List of operands to be concatenated
Cnode : Node_Id;
-- Node which is to be replaced by the result of concatenating the nodes
-- in the list Opnds.
begin
-- Ensure validity of both operands
Binary_Op_Validity_Checks (N);
-- If we are the left operand of a concatenation higher up the tree,
-- then do nothing for now, since we want to deal with a series of
-- concatenations as a unit.
if Nkind (Parent (N)) = N_Op_Concat
and then N = Left_Opnd (Parent (N))
then
return;
end if;
-- We get here with a concatenation whose left operand may be a
-- concatenation itself with a consistent type. We need to process
-- these concatenation operands from left to right, which means
-- from the deepest node in the tree to the highest node.
Cnode := N;
while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop
Cnode := Left_Opnd (Cnode);
end loop;
-- Now Cnode is the deepest concatenation, and its parents are the
-- concatenation nodes above, so now we process bottom up, doing the
-- operations. We gather a string that is as long as possible up to five
-- operands.
-- The outer loop runs more than once if more than one concatenation
-- type is involved.
Outer : loop
Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode));
Set_Parent (Opnds, N);
-- The inner loop gathers concatenation operands
Inner : while Cnode /= N
and then Base_Type (Etype (Cnode)) =
Base_Type (Etype (Parent (Cnode)))
loop
Cnode := Parent (Cnode);
Append (Right_Opnd (Cnode), Opnds);
end loop Inner;
Expand_Concatenate (Cnode, Opnds);
exit Outer when Cnode = N;
Cnode := Parent (Cnode);
end loop Outer;
end Expand_N_Op_Concat;
------------------------
-- Expand_N_Op_Divide --
------------------------
procedure Expand_N_Op_Divide (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Lopnd : constant Node_Id := Left_Opnd (N);
Ropnd : constant Node_Id := Right_Opnd (N);
Ltyp : constant Entity_Id := Etype (Lopnd);
Rtyp : constant Entity_Id := Etype (Ropnd);
Typ : Entity_Id := Etype (N);
Rknow : constant Boolean := Is_Integer_Type (Typ)
and then
Compile_Time_Known_Value (Ropnd);
Rval : Uint;
begin
Binary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- Otherwise proceed with expansion of division
if Rknow then
Rval := Expr_Value (Ropnd);
end if;
-- N / 1 = N for integer types
if Rknow and then Rval = Uint_1 then
Rewrite (N, Lopnd);
return;
end if;
-- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
-- Is_Power_Of_2_For_Shift is set means that we know that our left
-- operand is an unsigned integer, as required for this to work.
if Nkind (Ropnd) = N_Op_Expon
and then Is_Power_Of_2_For_Shift (Ropnd)
-- We cannot do this transformation in configurable run time mode if we
-- have 64-bit integers and long shifts are not available.
and then
(Esize (Ltyp) <= 32
or else Support_Long_Shifts_On_Target)
then
Rewrite (N,
Make_Op_Shift_Right (Loc,
Left_Opnd => Lopnd,
Right_Opnd =>
Convert_To (Standard_Natural, Right_Opnd (Ropnd))));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- Do required fixup of universal fixed operation
if Typ = Universal_Fixed then
Fixup_Universal_Fixed_Operation (N);
Typ := Etype (N);
end if;
-- Divisions with fixed-point results
if Is_Fixed_Point_Type (Typ) then
-- No special processing if Treat_Fixed_As_Integer is set, since
-- from a semantic point of view such operations are simply integer
-- operations and will be treated that way.
if not Treat_Fixed_As_Integer (N) then
if Is_Integer_Type (Rtyp) then
Expand_Divide_Fixed_By_Integer_Giving_Fixed (N);
else
Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N);
end if;
end if;
-- Other cases of division of fixed-point operands. Again we exclude the
-- case where Treat_Fixed_As_Integer is set.
elsif (Is_Fixed_Point_Type (Ltyp) or else
Is_Fixed_Point_Type (Rtyp))
and then not Treat_Fixed_As_Integer (N)
then
if Is_Integer_Type (Typ) then
Expand_Divide_Fixed_By_Fixed_Giving_Integer (N);
else
pragma Assert (Is_Floating_Point_Type (Typ));
Expand_Divide_Fixed_By_Fixed_Giving_Float (N);
end if;
-- Mixed-mode operations can appear in a non-static universal context,
-- in which case the integer argument must be converted explicitly.
elsif Typ = Universal_Real
and then Is_Integer_Type (Rtyp)
then
Rewrite (Ropnd,
Convert_To (Universal_Real, Relocate_Node (Ropnd)));
Analyze_And_Resolve (Ropnd, Universal_Real);
elsif Typ = Universal_Real
and then Is_Integer_Type (Ltyp)
then
Rewrite (Lopnd,
Convert_To (Universal_Real, Relocate_Node (Lopnd)));
Analyze_And_Resolve (Lopnd, Universal_Real);
-- Non-fixed point cases, do integer zero divide and overflow checks
elsif Is_Integer_Type (Typ) then
Apply_Divide_Checks (N);
-- Deal with Vax_Float
elsif Vax_Float (Typ) then
Expand_Vax_Arith (N);
return;
end if;
end Expand_N_Op_Divide;
--------------------
-- Expand_N_Op_Eq --
--------------------
procedure Expand_N_Op_Eq (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Lhs : constant Node_Id := Left_Opnd (N);
Rhs : constant Node_Id := Right_Opnd (N);
Bodies : constant List_Id := New_List;
A_Typ : constant Entity_Id := Etype (Lhs);
Typl : Entity_Id := A_Typ;
Op_Name : Entity_Id;
Prim : Elmt_Id;
procedure Build_Equality_Call (Eq : Entity_Id);
-- If a constructed equality exists for the type or for its parent,
-- build and analyze call, adding conversions if the operation is
-- inherited.
function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
-- Determines whether a type has a subcomponent of an unconstrained
-- Unchecked_Union subtype. Typ is a record type.
-------------------------
-- Build_Equality_Call --
-------------------------
procedure Build_Equality_Call (Eq : Entity_Id) is
Op_Type : constant Entity_Id := Etype (First_Formal (Eq));
L_Exp : Node_Id := Relocate_Node (Lhs);
R_Exp : Node_Id := Relocate_Node (Rhs);
begin
if Base_Type (Op_Type) /= Base_Type (A_Typ)
and then not Is_Class_Wide_Type (A_Typ)
then
L_Exp := OK_Convert_To (Op_Type, L_Exp);
R_Exp := OK_Convert_To (Op_Type, R_Exp);
end if;
-- If we have an Unchecked_Union, we need to add the inferred
-- discriminant values as actuals in the function call. At this
-- point, the expansion has determined that both operands have
-- inferable discriminants.
if Is_Unchecked_Union (Op_Type) then
declare
Lhs_Type : constant Node_Id := Etype (L_Exp);
Rhs_Type : constant Node_Id := Etype (R_Exp);
Lhs_Discr_Val : Node_Id;
Rhs_Discr_Val : Node_Id;
begin
-- Per-object constrained selected components require special
-- attention. If the enclosing scope of the component is an
-- Unchecked_Union, we cannot reference its discriminants
-- directly. This is why we use the two extra parameters of
-- the equality function of the enclosing Unchecked_Union.
-- type UU_Type (Discr : Integer := 0) is
-- . . .
-- end record;
-- pragma Unchecked_Union (UU_Type);
-- 1. Unchecked_Union enclosing record:
-- type Enclosing_UU_Type (Discr : Integer := 0) is record
-- . . .
-- Comp : UU_Type (Discr);
-- . . .
-- end Enclosing_UU_Type;
-- pragma Unchecked_Union (Enclosing_UU_Type);
-- Obj1 : Enclosing_UU_Type;
-- Obj2 : Enclosing_UU_Type (1);
-- [. . .] Obj1 = Obj2 [. . .]
-- Generated code:
-- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
-- A and B are the formal parameters of the equality function
-- of Enclosing_UU_Type. The function always has two extra
-- formals to capture the inferred discriminant values.
-- 2. Non-Unchecked_Union enclosing record:
-- type
-- Enclosing_Non_UU_Type (Discr : Integer := 0)
-- is record
-- . . .
-- Comp : UU_Type (Discr);
-- . . .
-- end Enclosing_Non_UU_Type;
-- Obj1 : Enclosing_Non_UU_Type;
-- Obj2 : Enclosing_Non_UU_Type (1);
-- ... Obj1 = Obj2 ...
-- Generated code:
-- if not (uu_typeEQ (obj1.comp, obj2.comp,
-- obj1.discr, obj2.discr)) then
-- In this case we can directly reference the discriminants of
-- the enclosing record.
-- Lhs of equality
if Nkind (Lhs) = N_Selected_Component
and then Has_Per_Object_Constraint
(Entity (Selector_Name (Lhs)))
then
-- Enclosing record is an Unchecked_Union, use formal A
if Is_Unchecked_Union
(Scope (Entity (Selector_Name (Lhs))))
then
Lhs_Discr_Val := Make_Identifier (Loc, Name_A);
-- Enclosing record is of a non-Unchecked_Union type, it is
-- possible to reference the discriminant.
else
Lhs_Discr_Val :=
Make_Selected_Component (Loc,
Prefix => Prefix (Lhs),
Selector_Name =>
New_Copy
(Get_Discriminant_Value
(First_Discriminant (Lhs_Type),
Lhs_Type,
Stored_Constraint (Lhs_Type))));
end if;
-- Comment needed here ???
else
-- Infer the discriminant value
Lhs_Discr_Val :=
New_Copy
(Get_Discriminant_Value
(First_Discriminant (Lhs_Type),
Lhs_Type,
Stored_Constraint (Lhs_Type)));
end if;
-- Rhs of equality
if Nkind (Rhs) = N_Selected_Component
and then Has_Per_Object_Constraint
(Entity (Selector_Name (Rhs)))
then
if Is_Unchecked_Union
(Scope (Entity (Selector_Name (Rhs))))
then
Rhs_Discr_Val := Make_Identifier (Loc, Name_B);
else
Rhs_Discr_Val :=
Make_Selected_Component (Loc,
Prefix => Prefix (Rhs),
Selector_Name =>
New_Copy (Get_Discriminant_Value (
First_Discriminant (Rhs_Type),
Rhs_Type,
Stored_Constraint (Rhs_Type))));
end if;
else
Rhs_Discr_Val :=
New_Copy (Get_Discriminant_Value (
First_Discriminant (Rhs_Type),
Rhs_Type,
Stored_Constraint (Rhs_Type)));
end if;
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (Eq, Loc),
Parameter_Associations => New_List (
L_Exp,
R_Exp,
Lhs_Discr_Val,
Rhs_Discr_Val)));
end;
-- Normal case, not an unchecked union
else
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (Eq, Loc),
Parameter_Associations => New_List (L_Exp, R_Exp)));
end if;
Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
end Build_Equality_Call;
------------------------------------
-- Has_Unconstrained_UU_Component --
------------------------------------
function Has_Unconstrained_UU_Component
(Typ : Node_Id) return Boolean
is
Tdef : constant Node_Id :=
Type_Definition (Declaration_Node (Base_Type (Typ)));
Clist : Node_Id;
Vpart : Node_Id;
function Component_Is_Unconstrained_UU
(Comp : Node_Id) return Boolean;
-- Determines whether the subtype of the component is an
-- unconstrained Unchecked_Union.
function Variant_Is_Unconstrained_UU
(Variant : Node_Id) return Boolean;
-- Determines whether a component of the variant has an unconstrained
-- Unchecked_Union subtype.
-----------------------------------
-- Component_Is_Unconstrained_UU --
-----------------------------------
function Component_Is_Unconstrained_UU
(Comp : Node_Id) return Boolean
is
begin
if Nkind (Comp) /= N_Component_Declaration then
return False;
end if;
declare
Sindic : constant Node_Id :=
Subtype_Indication (Component_Definition (Comp));
begin
-- Unconstrained nominal type. In the case of a constraint
-- present, the node kind would have been N_Subtype_Indication.
if Nkind (Sindic) = N_Identifier then
return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
end if;
return False;
end;
end Component_Is_Unconstrained_UU;
---------------------------------
-- Variant_Is_Unconstrained_UU --
---------------------------------
function Variant_Is_Unconstrained_UU
(Variant : Node_Id) return Boolean
is
Clist : constant Node_Id := Component_List (Variant);
begin
if Is_Empty_List (Component_Items (Clist)) then
return False;
end if;
-- We only need to test one component
declare
Comp : Node_Id := First (Component_Items (Clist));
begin
while Present (Comp) loop
if Component_Is_Unconstrained_UU (Comp) then
return True;
end if;
Next (Comp);
end loop;
end;
-- None of the components withing the variant were of
-- unconstrained Unchecked_Union type.
return False;
end Variant_Is_Unconstrained_UU;
-- Start of processing for Has_Unconstrained_UU_Component
begin
if Null_Present (Tdef) then
return False;
end if;
Clist := Component_List (Tdef);
Vpart := Variant_Part (Clist);
-- Inspect available components
if Present (Component_Items (Clist)) then
declare
Comp : Node_Id := First (Component_Items (Clist));
begin
while Present (Comp) loop
-- One component is sufficient
if Component_Is_Unconstrained_UU (Comp) then
return True;
end if;
Next (Comp);
end loop;
end;
end if;
-- Inspect available components withing variants
if Present (Vpart) then
declare
Variant : Node_Id := First (Variants (Vpart));
begin
while Present (Variant) loop
-- One component within a variant is sufficient
if Variant_Is_Unconstrained_UU (Variant) then
return True;
end if;
Next (Variant);
end loop;
end;
end if;
-- Neither the available components, nor the components inside the
-- variant parts were of an unconstrained Unchecked_Union subtype.
return False;
end Has_Unconstrained_UU_Component;
-- Start of processing for Expand_N_Op_Eq
begin
Binary_Op_Validity_Checks (N);
-- Deal with private types
if Ekind (Typl) = E_Private_Type then
Typl := Underlying_Type (Typl);
elsif Ekind (Typl) = E_Private_Subtype then
Typl := Underlying_Type (Base_Type (Typl));
else
null;
end if;
-- It may happen in error situations that the underlying type is not
-- set. The error will be detected later, here we just defend the
-- expander code.
if No (Typl) then
return;
end if;
Typl := Base_Type (Typl);
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
Expand_Compare_Minimize_Eliminate_Overflow (N);
if Nkind (N) /= N_Op_Eq then
return;
end if;
-- Boolean types (requiring handling of non-standard case)
if Is_Boolean_Type (Typl) then
Adjust_Condition (Left_Opnd (N));
Adjust_Condition (Right_Opnd (N));
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
-- Array types
elsif Is_Array_Type (Typl) then
-- If we are doing full validity checking, and it is possible for the
-- array elements to be invalid then expand out array comparisons to
-- make sure that we check the array elements.
if Validity_Check_Operands
and then not Is_Known_Valid (Component_Type (Typl))
then
declare
Save_Force_Validity_Checks : constant Boolean :=
Force_Validity_Checks;
begin
Force_Validity_Checks := True;
Rewrite (N,
Expand_Array_Equality
(N,
Relocate_Node (Lhs),
Relocate_Node (Rhs),
Bodies,
Typl));
Insert_Actions (N, Bodies);
Analyze_And_Resolve (N, Standard_Boolean);
Force_Validity_Checks := Save_Force_Validity_Checks;
end;
-- Packed case where both operands are known aligned
elsif Is_Bit_Packed_Array (Typl)
and then not Is_Possibly_Unaligned_Object (Lhs)
and then not Is_Possibly_Unaligned_Object (Rhs)
then
Expand_Packed_Eq (N);
-- Where the component type is elementary we can use a block bit
-- comparison (if supported on the target) exception in the case
-- of floating-point (negative zero issues require element by
-- element comparison), and atomic types (where we must be sure
-- to load elements independently) and possibly unaligned arrays.
elsif Is_Elementary_Type (Component_Type (Typl))
and then not Is_Floating_Point_Type (Component_Type (Typl))
and then not Is_Atomic (Component_Type (Typl))
and then not Is_Possibly_Unaligned_Object (Lhs)
and then not Is_Possibly_Unaligned_Object (Rhs)
and then Support_Composite_Compare_On_Target
then
null;
-- For composite and floating-point cases, expand equality loop to
-- make sure of using proper comparisons for tagged types, and
-- correctly handling the floating-point case.
else
Rewrite (N,
Expand_Array_Equality
(N,
Relocate_Node (Lhs),
Relocate_Node (Rhs),
Bodies,
Typl));
Insert_Actions (N, Bodies, Suppress => All_Checks);
Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
end if;
-- Record Types
elsif Is_Record_Type (Typl) then
-- For tagged types, use the primitive "="
if Is_Tagged_Type (Typl) then
-- No need to do anything else compiling under restriction
-- No_Dispatching_Calls. During the semantic analysis we
-- already notified such violation.
if Restriction_Active (No_Dispatching_Calls) then
return;
end if;
-- If this is derived from an untagged private type completed with
-- a tagged type, it does not have a full view, so we use the
-- primitive operations of the private type. This check should no
-- longer be necessary when these types get their full views???
if Is_Private_Type (A_Typ)
and then not Is_Tagged_Type (A_Typ)
and then Is_Derived_Type (A_Typ)
and then No (Full_View (A_Typ))
then
-- Search for equality operation, checking that the operands
-- have the same type. Note that we must find a matching entry,
-- or something is very wrong!
Prim := First_Elmt (Collect_Primitive_Operations (A_Typ));
while Present (Prim) loop
exit when Chars (Node (Prim)) = Name_Op_Eq
and then Etype (First_Formal (Node (Prim))) =
Etype (Next_Formal (First_Formal (Node (Prim))))
and then
Base_Type (Etype (Node (Prim))) = Standard_Boolean;
Next_Elmt (Prim);
end loop;
pragma Assert (Present (Prim));
Op_Name := Node (Prim);
-- Find the type's predefined equality or an overriding
-- user- defined equality. The reason for not simply calling
-- Find_Prim_Op here is that there may be a user-defined
-- overloaded equality op that precedes the equality that we want,
-- so we have to explicitly search (e.g., there could be an
-- equality with two different parameter types).
else
if Is_Class_Wide_Type (Typl) then
Typl := Root_Type (Typl);
end if;
Prim := First_Elmt (Primitive_Operations (Typl));
while Present (Prim) loop
exit when Chars (Node (Prim)) = Name_Op_Eq
and then Etype (First_Formal (Node (Prim))) =
Etype (Next_Formal (First_Formal (Node (Prim))))
and then
Base_Type (Etype (Node (Prim))) = Standard_Boolean;
Next_Elmt (Prim);
end loop;
pragma Assert (Present (Prim));
Op_Name := Node (Prim);
end if;
Build_Equality_Call (Op_Name);
-- Ada 2005 (AI-216): Program_Error is raised when evaluating the
-- predefined equality operator for a type which has a subcomponent
-- of an Unchecked_Union type whose nominal subtype is unconstrained.
elsif Has_Unconstrained_UU_Component (Typl) then
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
-- Prevent Gigi from generating incorrect code by rewriting the
-- equality as a standard False. (is this documented somewhere???)
Rewrite (N,
New_Occurrence_Of (Standard_False, Loc));
elsif Is_Unchecked_Union (Typl) then
-- If we can infer the discriminants of the operands, we make a
-- call to the TSS equality function.
if Has_Inferable_Discriminants (Lhs)
and then
Has_Inferable_Discriminants (Rhs)
then
Build_Equality_Call
(TSS (Root_Type (Typl), TSS_Composite_Equality));
else
-- Ada 2005 (AI-216): Program_Error is raised when evaluating
-- the predefined equality operator for an Unchecked_Union type
-- if either of the operands lack inferable discriminants.
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction));
-- Prevent Gigi from generating incorrect code by rewriting
-- the equality as a standard False (documented where???).
Rewrite (N,
New_Occurrence_Of (Standard_False, Loc));
end if;
-- If a type support function is present (for complex cases), use it
elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
Build_Equality_Call
(TSS (Root_Type (Typl), TSS_Composite_Equality));
-- Otherwise expand the component by component equality. Note that
-- we never use block-bit comparisons for records, because of the
-- problems with gaps. The backend will often be able to recombine
-- the separate comparisons that we generate here.
else
Remove_Side_Effects (Lhs);
Remove_Side_Effects (Rhs);
Rewrite (N,
Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies));
Insert_Actions (N, Bodies, Suppress => All_Checks);
Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
end if;
end if;
-- Test if result is known at compile time
Rewrite_Comparison (N);
-- If we still have comparison for Vax_Float, process it
if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then
Expand_Vax_Comparison (N);
return;
end if;
Optimize_Length_Comparison (N);
end Expand_N_Op_Eq;
-----------------------
-- Expand_N_Op_Expon --
-----------------------
procedure Expand_N_Op_Expon (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Rtyp : constant Entity_Id := Root_Type (Typ);
Base : constant Node_Id := Relocate_Node (Left_Opnd (N));
Bastyp : constant Node_Id := Etype (Base);
Exp : constant Node_Id := Relocate_Node (Right_Opnd (N));
Exptyp : constant Entity_Id := Etype (Exp);
Ovflo : constant Boolean := Do_Overflow_Check (N);
Expv : Uint;
Temp : Node_Id;
Rent : RE_Id;
Ent : Entity_Id;
Etyp : Entity_Id;
Xnode : Node_Id;
begin
Binary_Op_Validity_Checks (N);
-- CodePeer and GNATprove want to see the unexpanded N_Op_Expon node
if CodePeer_Mode or Alfa_Mode then
return;
end if;
-- If either operand is of a private type, then we have the use of an
-- intrinsic operator, and we get rid of the privateness, by using root
-- types of underlying types for the actual operation. Otherwise the
-- private types will cause trouble if we expand multiplications or
-- shifts etc. We also do this transformation if the result type is
-- different from the base type.
if Is_Private_Type (Etype (Base))
or else Is_Private_Type (Typ)
or else Is_Private_Type (Exptyp)
or else Rtyp /= Root_Type (Bastyp)
then
declare
Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp));
Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp));
begin
Rewrite (N,
Unchecked_Convert_To (Typ,
Make_Op_Expon (Loc,
Left_Opnd => Unchecked_Convert_To (Bt, Base),
Right_Opnd => Unchecked_Convert_To (Et, Exp))));
Analyze_And_Resolve (N, Typ);
return;
end;
end if;
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- Test for case of known right argument where we can replace the
-- exponentiation by an equivalent expression using multiplication.
if Compile_Time_Known_Value (Exp) then
Expv := Expr_Value (Exp);
-- We only fold small non-negative exponents. You might think we
-- could fold small negative exponents for the real case, but we
-- can't because we are required to raise Constraint_Error for
-- the case of 0.0 ** (negative) even if Machine_Overflows = False.
-- See ACVC test C4A012B.
if Expv >= 0 and then Expv <= 4 then
-- X ** 0 = 1 (or 1.0)
if Expv = 0 then
-- Call Remove_Side_Effects to ensure that any side effects
-- in the ignored left operand (in particular function calls
-- to user defined functions) are properly executed.
Remove_Side_Effects (Base);
if Ekind (Typ) in Integer_Kind then
Xnode := Make_Integer_Literal (Loc, Intval => 1);
else
Xnode := Make_Real_Literal (Loc, Ureal_1);
end if;
-- X ** 1 = X
elsif Expv = 1 then
Xnode := Base;
-- X ** 2 = X * X
elsif Expv = 2 then
Xnode :=
Make_Op_Multiply (Loc,
Left_Opnd => Duplicate_Subexpr (Base),
Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
-- X ** 3 = X * X * X
elsif Expv = 3 then
Xnode :=
Make_Op_Multiply (Loc,
Left_Opnd =>
Make_Op_Multiply (Loc,
Left_Opnd => Duplicate_Subexpr (Base),
Right_Opnd => Duplicate_Subexpr_No_Checks (Base)),
Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
-- X ** 4 ->
-- do
-- En : constant base'type := base * base;
-- in
-- En * En
else
pragma Assert (Expv = 4);
Temp := Make_Temporary (Loc, 'E', Base);
Xnode :=
Make_Expression_With_Actions (Loc,
Actions => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Constant_Present => True,
Object_Definition => New_Reference_To (Typ, Loc),
Expression =>
Make_Op_Multiply (Loc,
Left_Opnd =>
Duplicate_Subexpr (Base),
Right_Opnd =>
Duplicate_Subexpr_No_Checks (Base)))),
Expression =>
Make_Op_Multiply (Loc,
Left_Opnd => New_Reference_To (Temp, Loc),
Right_Opnd => New_Reference_To (Temp, Loc)));
end if;
Rewrite (N, Xnode);
Analyze_And_Resolve (N, Typ);
return;
end if;
end if;
-- Case of (2 ** expression) appearing as an argument of an integer
-- multiplication, or as the right argument of a division of a non-
-- negative integer. In such cases we leave the node untouched, setting
-- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
-- of the higher level node converts it into a shift.
-- Another case is 2 ** N in any other context. We simply convert
-- this to 1 * 2 ** N, and then the above transformation applies.
-- Note: this transformation is not applicable for a modular type with
-- a non-binary modulus in the multiplication case, since we get a wrong
-- result if the shift causes an overflow before the modular reduction.
if Nkind (Base) = N_Integer_Literal
and then Intval (Base) = 2
and then Is_Integer_Type (Root_Type (Exptyp))
and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer)
and then Is_Unsigned_Type (Exptyp)
and then not Ovflo
then
-- First the multiply and divide cases
if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
declare
P : constant Node_Id := Parent (N);
L : constant Node_Id := Left_Opnd (P);
R : constant Node_Id := Right_Opnd (P);
begin
if (Nkind (P) = N_Op_Multiply
and then not Non_Binary_Modulus (Typ)
and then
((Is_Integer_Type (Etype (L)) and then R = N)
or else
(Is_Integer_Type (Etype (R)) and then L = N))
and then not Do_Overflow_Check (P))
or else
(Nkind (P) = N_Op_Divide
and then Is_Integer_Type (Etype (L))
and then Is_Unsigned_Type (Etype (L))
and then R = N
and then not Do_Overflow_Check (P))
then
Set_Is_Power_Of_2_For_Shift (N);
return;
end if;
end;
-- Now the other cases
elsif not Non_Binary_Modulus (Typ) then
Rewrite (N,
Make_Op_Multiply (Loc,
Left_Opnd => Make_Integer_Literal (Loc, 1),
Right_Opnd => Relocate_Node (N)));
Analyze_And_Resolve (N, Typ);
return;
end if;
end if;
-- Fall through if exponentiation must be done using a runtime routine
-- First deal with modular case
if Is_Modular_Integer_Type (Rtyp) then
-- Non-binary case, we call the special exponentiation routine for
-- the non-binary case, converting the argument to Long_Long_Integer
-- and passing the modulus value. Then the result is converted back
-- to the base type.
if Non_Binary_Modulus (Rtyp) then
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Exp_Modular), Loc),
Parameter_Associations => New_List (
Convert_To (Standard_Integer, Base),
Make_Integer_Literal (Loc, Modulus (Rtyp)),
Exp))));
-- Binary case, in this case, we call one of two routines, either the
-- unsigned integer case, or the unsigned long long integer case,
-- with a final "and" operation to do the required mod.
else
if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then
Ent := RTE (RE_Exp_Unsigned);
else
Ent := RTE (RE_Exp_Long_Long_Unsigned);
end if;
Rewrite (N,
Convert_To (Typ,
Make_Op_And (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name => New_Reference_To (Ent, Loc),
Parameter_Associations => New_List (
Convert_To (Etype (First_Formal (Ent)), Base),
Exp)),
Right_Opnd =>
Make_Integer_Literal (Loc, Modulus (Rtyp) - 1))));
end if;
-- Common exit point for modular type case
Analyze_And_Resolve (N, Typ);
return;
-- Signed integer cases, done using either Integer or Long_Long_Integer.
-- It is not worth having routines for Short_[Short_]Integer, since for
-- most machines it would not help, and it would generate more code that
-- might need certification when a certified run time is required.
-- In the integer cases, we have two routines, one for when overflow
-- checks are required, and one when they are not required, since there
-- is a real gain in omitting checks on many machines.
elsif Rtyp = Base_Type (Standard_Long_Long_Integer)
or else (Rtyp = Base_Type (Standard_Long_Integer)
and then
Esize (Standard_Long_Integer) > Esize (Standard_Integer))
or else (Rtyp = Universal_Integer)
then
Etyp := Standard_Long_Long_Integer;
if Ovflo then
Rent := RE_Exp_Long_Long_Integer;
else
Rent := RE_Exn_Long_Long_Integer;
end if;
elsif Is_Signed_Integer_Type (Rtyp) then
Etyp := Standard_Integer;
if Ovflo then
Rent := RE_Exp_Integer;
else
Rent := RE_Exn_Integer;
end if;
-- Floating-point cases, always done using Long_Long_Float. We do not
-- need separate routines for the overflow case here, since in the case
-- of floating-point, we generate infinities anyway as a rule (either
-- that or we automatically trap overflow), and if there is an infinity
-- generated and a range check is required, the check will fail anyway.
else
pragma Assert (Is_Floating_Point_Type (Rtyp));
Etyp := Standard_Long_Long_Float;
Rent := RE_Exn_Long_Long_Float;
end if;
-- Common processing for integer cases and floating-point cases.
-- If we are in the right type, we can call runtime routine directly
if Typ = Etyp
and then Rtyp /= Universal_Integer
and then Rtyp /= Universal_Real
then
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (Rent), Loc),
Parameter_Associations => New_List (Base, Exp)));
-- Otherwise we have to introduce conversions (conversions are also
-- required in the universal cases, since the runtime routine is
-- typed using one of the standard types).
else
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (Rent), Loc),
Parameter_Associations => New_List (
Convert_To (Etyp, Base),
Exp))));
end if;
Analyze_And_Resolve (N, Typ);
return;
exception
when RE_Not_Available =>
return;
end Expand_N_Op_Expon;
--------------------
-- Expand_N_Op_Ge --
--------------------
procedure Expand_N_Op_Ge (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
Op1 : constant Node_Id := Left_Opnd (N);
Op2 : constant Node_Id := Right_Opnd (N);
Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
begin
Binary_Op_Validity_Checks (N);
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
Expand_Compare_Minimize_Eliminate_Overflow (N);
if Nkind (N) /= N_Op_Ge then
return;
end if;
-- Array type case
if Is_Array_Type (Typ1) then
Expand_Array_Comparison (N);
return;
end if;
-- Deal with boolean operands
if Is_Boolean_Type (Typ1) then
Adjust_Condition (Op1);
Adjust_Condition (Op2);
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
end if;
Rewrite_Comparison (N);
-- If we still have comparison, and Vax_Float type, process it
if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
Expand_Vax_Comparison (N);
return;
end if;
Optimize_Length_Comparison (N);
end Expand_N_Op_Ge;
--------------------
-- Expand_N_Op_Gt --
--------------------
procedure Expand_N_Op_Gt (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
Op1 : constant Node_Id := Left_Opnd (N);
Op2 : constant Node_Id := Right_Opnd (N);
Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
begin
Binary_Op_Validity_Checks (N);
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
Expand_Compare_Minimize_Eliminate_Overflow (N);
if Nkind (N) /= N_Op_Gt then
return;
end if;
-- Deal with array type operands
if Is_Array_Type (Typ1) then
Expand_Array_Comparison (N);
return;
end if;
-- Deal with boolean type operands
if Is_Boolean_Type (Typ1) then
Adjust_Condition (Op1);
Adjust_Condition (Op2);
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
end if;
Rewrite_Comparison (N);
-- If we still have comparison, and Vax_Float type, process it
if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
Expand_Vax_Comparison (N);
return;
end if;
Optimize_Length_Comparison (N);
end Expand_N_Op_Gt;
--------------------
-- Expand_N_Op_Le --
--------------------
procedure Expand_N_Op_Le (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
Op1 : constant Node_Id := Left_Opnd (N);
Op2 : constant Node_Id := Right_Opnd (N);
Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
begin
Binary_Op_Validity_Checks (N);
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
Expand_Compare_Minimize_Eliminate_Overflow (N);
if Nkind (N) /= N_Op_Le then
return;
end if;
-- Deal with array type operands
if Is_Array_Type (Typ1) then
Expand_Array_Comparison (N);
return;
end if;
-- Deal with Boolean type operands
if Is_Boolean_Type (Typ1) then
Adjust_Condition (Op1);
Adjust_Condition (Op2);
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
end if;
Rewrite_Comparison (N);
-- If we still have comparison, and Vax_Float type, process it
if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
Expand_Vax_Comparison (N);
return;
end if;
Optimize_Length_Comparison (N);
end Expand_N_Op_Le;
--------------------
-- Expand_N_Op_Lt --
--------------------
procedure Expand_N_Op_Lt (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
Op1 : constant Node_Id := Left_Opnd (N);
Op2 : constant Node_Id := Right_Opnd (N);
Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
begin
Binary_Op_Validity_Checks (N);
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
Expand_Compare_Minimize_Eliminate_Overflow (N);
if Nkind (N) /= N_Op_Lt then
return;
end if;
-- Deal with array type operands
if Is_Array_Type (Typ1) then
Expand_Array_Comparison (N);
return;
end if;
-- Deal with Boolean type operands
if Is_Boolean_Type (Typ1) then
Adjust_Condition (Op1);
Adjust_Condition (Op2);
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
end if;
Rewrite_Comparison (N);
-- If we still have comparison, and Vax_Float type, process it
if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
Expand_Vax_Comparison (N);
return;
end if;
Optimize_Length_Comparison (N);
end Expand_N_Op_Lt;
-----------------------
-- Expand_N_Op_Minus --
-----------------------
procedure Expand_N_Op_Minus (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
begin
Unary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
if not Backend_Overflow_Checks_On_Target
and then Is_Signed_Integer_Type (Etype (N))
and then Do_Overflow_Check (N)
then
-- Software overflow checking expands -expr into (0 - expr)
Rewrite (N,
Make_Op_Subtract (Loc,
Left_Opnd => Make_Integer_Literal (Loc, 0),
Right_Opnd => Right_Opnd (N)));
Analyze_And_Resolve (N, Typ);
-- Vax floating-point types case
elsif Vax_Float (Etype (N)) then
Expand_Vax_Arith (N);
end if;
end Expand_N_Op_Minus;
---------------------
-- Expand_N_Op_Mod --
---------------------
procedure Expand_N_Op_Mod (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
DDC : constant Boolean := Do_Division_Check (N);
Left : Node_Id;
Right : Node_Id;
LLB : Uint;
Llo : Uint;
Lhi : Uint;
LOK : Boolean;
Rlo : Uint;
Rhi : Uint;
ROK : Boolean;
pragma Warnings (Off, Lhi);
begin
Binary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
if Is_Integer_Type (Etype (N)) then
Apply_Divide_Checks (N);
-- All done if we don't have a MOD any more, which can happen as a
-- result of overflow expansion in MINIMIZED or ELIMINATED modes.
if Nkind (N) /= N_Op_Mod then
return;
end if;
end if;
-- Proceed with expansion of mod operator
Left := Left_Opnd (N);
Right := Right_Opnd (N);
Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True);
Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True);
-- Convert mod to rem if operands are known non-negative. We do this
-- since it is quite likely that this will improve the quality of code,
-- (the operation now corresponds to the hardware remainder), and it
-- does not seem likely that it could be harmful.
if LOK and then Llo >= 0
and then
ROK and then Rlo >= 0
then
Rewrite (N,
Make_Op_Rem (Sloc (N),
Left_Opnd => Left_Opnd (N),
Right_Opnd => Right_Opnd (N)));
-- Instead of reanalyzing the node we do the analysis manually. This
-- avoids anomalies when the replacement is done in an instance and
-- is epsilon more efficient.
Set_Entity (N, Standard_Entity (S_Op_Rem));
Set_Etype (N, Typ);
Set_Do_Division_Check (N, DDC);
Expand_N_Op_Rem (N);
Set_Analyzed (N);
-- Otherwise, normal mod processing
else
-- Apply optimization x mod 1 = 0. We don't really need that with
-- gcc, but it is useful with other back ends (e.g. AAMP), and is
-- certainly harmless.
if Is_Integer_Type (Etype (N))
and then Compile_Time_Known_Value (Right)
and then Expr_Value (Right) = Uint_1
then
-- Call Remove_Side_Effects to ensure that any side effects in
-- the ignored left operand (in particular function calls to
-- user defined functions) are properly executed.
Remove_Side_Effects (Left);
Rewrite (N, Make_Integer_Literal (Loc, 0));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- Deal with annoying case of largest negative number remainder
-- minus one. Gigi may not handle this case correctly, because
-- on some targets, the mod value is computed using a divide
-- instruction which gives an overflow trap for this case.
-- It would be a bit more efficient to figure out which targets
-- this is really needed for, but in practice it is reasonable
-- to do the following special check in all cases, since it means
-- we get a clearer message, and also the overhead is minimal given
-- that division is expensive in any case.
-- In fact the check is quite easy, if the right operand is -1, then
-- the mod value is always 0, and we can just ignore the left operand
-- completely in this case.
-- This only applies if we still have a mod operator. Skip if we
-- have already rewritten this (e.g. in the case of eliminated
-- overflow checks which have driven us into bignum mode).
if Nkind (N) = N_Op_Mod then
-- The operand type may be private (e.g. in the expansion of an
-- intrinsic operation) so we must use the underlying type to get
-- the bounds, and convert the literals explicitly.
LLB :=
Expr_Value
(Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
and then
((not LOK) or else (Llo = LLB))
then
Rewrite (N,
Make_If_Expression (Loc,
Expressions => New_List (
Make_Op_Eq (Loc,
Left_Opnd => Duplicate_Subexpr (Right),
Right_Opnd =>
Unchecked_Convert_To (Typ,
Make_Integer_Literal (Loc, -1))),
Unchecked_Convert_To (Typ,
Make_Integer_Literal (Loc, Uint_0)),
Relocate_Node (N))));
Set_Analyzed (Next (Next (First (Expressions (N)))));
Analyze_And_Resolve (N, Typ);
end if;
end if;
end if;
end Expand_N_Op_Mod;
--------------------------
-- Expand_N_Op_Multiply --
--------------------------
procedure Expand_N_Op_Multiply (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Lop : constant Node_Id := Left_Opnd (N);
Rop : constant Node_Id := Right_Opnd (N);
Lp2 : constant Boolean :=
Nkind (Lop) = N_Op_Expon
and then Is_Power_Of_2_For_Shift (Lop);
Rp2 : constant Boolean :=
Nkind (Rop) = N_Op_Expon
and then Is_Power_Of_2_For_Shift (Rop);
Ltyp : constant Entity_Id := Etype (Lop);
Rtyp : constant Entity_Id := Etype (Rop);
Typ : Entity_Id := Etype (N);
begin
Binary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- Special optimizations for integer types
if Is_Integer_Type (Typ) then
-- N * 0 = 0 for integer types
if Compile_Time_Known_Value (Rop)
and then Expr_Value (Rop) = Uint_0
then
-- Call Remove_Side_Effects to ensure that any side effects in
-- the ignored left operand (in particular function calls to
-- user defined functions) are properly executed.
Remove_Side_Effects (Lop);
Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- Similar handling for 0 * N = 0
if Compile_Time_Known_Value (Lop)
and then Expr_Value (Lop) = Uint_0
then
Remove_Side_Effects (Rop);
Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- N * 1 = 1 * N = N for integer types
-- This optimisation is not done if we are going to
-- rewrite the product 1 * 2 ** N to a shift.
if Compile_Time_Known_Value (Rop)
and then Expr_Value (Rop) = Uint_1
and then not Lp2
then
Rewrite (N, Lop);
return;
elsif Compile_Time_Known_Value (Lop)
and then Expr_Value (Lop) = Uint_1
and then not Rp2
then
Rewrite (N, Rop);
return;
end if;
end if;
-- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
-- Is_Power_Of_2_For_Shift is set means that we know that our left
-- operand is an integer, as required for this to work.
if Rp2 then
if Lp2 then
-- Convert 2 ** A * 2 ** B into 2 ** (A + B)
Rewrite (N,
Make_Op_Expon (Loc,
Left_Opnd => Make_Integer_Literal (Loc, 2),
Right_Opnd =>
Make_Op_Add (Loc,
Left_Opnd => Right_Opnd (Lop),
Right_Opnd => Right_Opnd (Rop))));
Analyze_And_Resolve (N, Typ);
return;
else
Rewrite (N,
Make_Op_Shift_Left (Loc,
Left_Opnd => Lop,
Right_Opnd =>
Convert_To (Standard_Natural, Right_Opnd (Rop))));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- Same processing for the operands the other way round
elsif Lp2 then
Rewrite (N,
Make_Op_Shift_Left (Loc,
Left_Opnd => Rop,
Right_Opnd =>
Convert_To (Standard_Natural, Right_Opnd (Lop))));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- Do required fixup of universal fixed operation
if Typ = Universal_Fixed then
Fixup_Universal_Fixed_Operation (N);
Typ := Etype (N);
end if;
-- Multiplications with fixed-point results
if Is_Fixed_Point_Type (Typ) then
-- No special processing if Treat_Fixed_As_Integer is set, since from
-- a semantic point of view such operations are simply integer
-- operations and will be treated that way.
if not Treat_Fixed_As_Integer (N) then
-- Case of fixed * integer => fixed
if Is_Integer_Type (Rtyp) then
Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N);
-- Case of integer * fixed => fixed
elsif Is_Integer_Type (Ltyp) then
Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N);
-- Case of fixed * fixed => fixed
else
Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N);
end if;
end if;
-- Other cases of multiplication of fixed-point operands. Again we
-- exclude the cases where Treat_Fixed_As_Integer flag is set.
elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp))
and then not Treat_Fixed_As_Integer (N)
then
if Is_Integer_Type (Typ) then
Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N);
else
pragma Assert (Is_Floating_Point_Type (Typ));
Expand_Multiply_Fixed_By_Fixed_Giving_Float (N);
end if;
-- Mixed-mode operations can appear in a non-static universal context,
-- in which case the integer argument must be converted explicitly.
elsif Typ = Universal_Real
and then Is_Integer_Type (Rtyp)
then
Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop)));
Analyze_And_Resolve (Rop, Universal_Real);
elsif Typ = Universal_Real
and then Is_Integer_Type (Ltyp)
then
Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop)));
Analyze_And_Resolve (Lop, Universal_Real);
-- Non-fixed point cases, check software overflow checking required
elsif Is_Signed_Integer_Type (Etype (N)) then
Apply_Arithmetic_Overflow_Check (N);
-- Deal with VAX float case
elsif Vax_Float (Typ) then
Expand_Vax_Arith (N);
return;
end if;
end Expand_N_Op_Multiply;
--------------------
-- Expand_N_Op_Ne --
--------------------
procedure Expand_N_Op_Ne (N : Node_Id) is
Typ : constant Entity_Id := Etype (Left_Opnd (N));
begin
-- Case of elementary type with standard operator
if Is_Elementary_Type (Typ)
and then Sloc (Entity (N)) = Standard_Location
then
Binary_Op_Validity_Checks (N);
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if
-- means we no longer have a /= operation, we are all done.
Expand_Compare_Minimize_Eliminate_Overflow (N);
if Nkind (N) /= N_Op_Ne then
return;
end if;
-- Boolean types (requiring handling of non-standard case)
if Is_Boolean_Type (Typ) then
Adjust_Condition (Left_Opnd (N));
Adjust_Condition (Right_Opnd (N));
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
end if;
Rewrite_Comparison (N);
-- If we still have comparison for Vax_Float, process it
if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then
Expand_Vax_Comparison (N);
return;
end if;
-- For all cases other than elementary types, we rewrite node as the
-- negation of an equality operation, and reanalyze. The equality to be
-- used is defined in the same scope and has the same signature. This
-- signature must be set explicitly since in an instance it may not have
-- the same visibility as in the generic unit. This avoids duplicating
-- or factoring the complex code for record/array equality tests etc.
else
declare
Loc : constant Source_Ptr := Sloc (N);
Neg : Node_Id;
Ne : constant Entity_Id := Entity (N);
begin
Binary_Op_Validity_Checks (N);
Neg :=
Make_Op_Not (Loc,
Right_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => Left_Opnd (N),
Right_Opnd => Right_Opnd (N)));
Set_Paren_Count (Right_Opnd (Neg), 1);
if Scope (Ne) /= Standard_Standard then
Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne));
end if;
-- For navigation purposes, we want to treat the inequality as an
-- implicit reference to the corresponding equality. Preserve the
-- Comes_From_ source flag to generate proper Xref entries.
Preserve_Comes_From_Source (Neg, N);
Preserve_Comes_From_Source (Right_Opnd (Neg), N);
Rewrite (N, Neg);
Analyze_And_Resolve (N, Standard_Boolean);
end;
end if;
Optimize_Length_Comparison (N);
end Expand_N_Op_Ne;
---------------------
-- Expand_N_Op_Not --
---------------------
-- If the argument is other than a Boolean array type, there is no special
-- expansion required, except for VMS operations on signed integers.
-- For the packed case, we call the special routine in Exp_Pakd, except
-- that if the component size is greater than one, we use the standard
-- routine generating a gruesome loop (it is so peculiar to have packed
-- arrays with non-standard Boolean representations anyway, so it does not
-- matter that we do not handle this case efficiently).
-- For the unpacked case (and for the special packed case where we have non
-- standard Booleans, as discussed above), we generate and insert into the
-- tree the following function definition:
-- function Nnnn (A : arr) is
-- B : arr;
-- begin
-- for J in a'range loop
-- B (J) := not A (J);
-- end loop;
-- return B;
-- end Nnnn;
-- Here arr is the actual subtype of the parameter (and hence always
-- constrained). Then we replace the not with a call to this function.
procedure Expand_N_Op_Not (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Opnd : Node_Id;
Arr : Entity_Id;
A : Entity_Id;
B : Entity_Id;
J : Entity_Id;
A_J : Node_Id;
B_J : Node_Id;
Func_Name : Entity_Id;
Loop_Statement : Node_Id;
begin
Unary_Op_Validity_Checks (N);
-- For boolean operand, deal with non-standard booleans
if Is_Boolean_Type (Typ) then
Adjust_Condition (Right_Opnd (N));
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
return;
end if;
-- For the VMS "not" on signed integer types, use conversion to and from
-- a predefined modular type.
if Is_VMS_Operator (Entity (N)) then
declare
Rtyp : Entity_Id;
Utyp : Entity_Id;
begin
-- If this is a derived type, retrieve original VMS type so that
-- the proper sized type is used for intermediate values.
if Is_Derived_Type (Typ) then
Rtyp := First_Subtype (Etype (Typ));
else
Rtyp := Typ;
end if;
-- The proper unsigned type must have a size compatible with the
-- operand, to prevent misalignment.
if RM_Size (Rtyp) <= 8 then
Utyp := RTE (RE_Unsigned_8);
elsif RM_Size (Rtyp) <= 16 then
Utyp := RTE (RE_Unsigned_16);
elsif RM_Size (Rtyp) = RM_Size (Standard_Unsigned) then
Utyp := RTE (RE_Unsigned_32);
else
Utyp := RTE (RE_Long_Long_Unsigned);
end if;
Rewrite (N,
Unchecked_Convert_To (Typ,
Make_Op_Not (Loc,
Unchecked_Convert_To (Utyp, Right_Opnd (N)))));
Analyze_And_Resolve (N, Typ);
return;
end;
end if;
-- Only array types need any other processing
if not Is_Array_Type (Typ) then
return;
end if;
-- Case of array operand. If bit packed with a component size of 1,
-- handle it in Exp_Pakd if the operand is known to be aligned.
if Is_Bit_Packed_Array (Typ)
and then Component_Size (Typ) = 1
and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
then
Expand_Packed_Not (N);
return;
end if;
-- Case of array operand which is not bit-packed. If the context is
-- a safe assignment, call in-place operation, If context is a larger
-- boolean expression in the context of a safe assignment, expansion is
-- done by enclosing operation.
Opnd := Relocate_Node (Right_Opnd (N));
Convert_To_Actual_Subtype (Opnd);
Arr := Etype (Opnd);
Ensure_Defined (Arr, N);
Silly_Boolean_Array_Not_Test (N, Arr);
if Nkind (Parent (N)) = N_Assignment_Statement then
if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then
Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
return;
-- Special case the negation of a binary operation
elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor)
and then Safe_In_Place_Array_Op
(Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd))
then
Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
return;
end if;
elsif Nkind (Parent (N)) in N_Binary_Op
and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
then
declare
Op1 : constant Node_Id := Left_Opnd (Parent (N));
Op2 : constant Node_Id := Right_Opnd (Parent (N));
Lhs : constant Node_Id := Name (Parent (Parent (N)));
begin
if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then
-- (not A) op (not B) can be reduced to a single call
if N = Op1 and then Nkind (Op2) = N_Op_Not then
return;
elsif N = Op2 and then Nkind (Op1) = N_Op_Not then
return;
-- A xor (not B) can also be special-cased
elsif N = Op2 and then Nkind (Parent (N)) = N_Op_Xor then
return;
end if;
end if;
end;
end if;
A := Make_Defining_Identifier (Loc, Name_uA);
B := Make_Defining_Identifier (Loc, Name_uB);
J := Make_Defining_Identifier (Loc, Name_uJ);
A_J :=
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (A, Loc),
Expressions => New_List (New_Reference_To (J, Loc)));
B_J :=
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (B, Loc),
Expressions => New_List (New_Reference_To (J, Loc)));
Loop_Statement :=
Make_Implicit_Loop_Statement (N,
Identifier => Empty,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => J,
Discrete_Subtype_Definition =>
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Chars (A)),
Attribute_Name => Name_Range))),
Statements => New_List (
Make_Assignment_Statement (Loc,
Name => B_J,
Expression => Make_Op_Not (Loc, A_J))));
Func_Name := Make_Temporary (Loc, 'N');
Set_Is_Inlined (Func_Name);
Insert_Action (N,
Make_Subprogram_Body (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Func_Name,
Parameter_Specifications => New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => A,
Parameter_Type => New_Reference_To (Typ, Loc))),
Result_Definition => New_Reference_To (Typ, Loc)),
Declarations => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => B,
Object_Definition => New_Reference_To (Arr, Loc))),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Loop_Statement,
Make_Simple_Return_Statement (Loc,
Expression => Make_Identifier (Loc, Chars (B)))))));
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (Func_Name, Loc),
Parameter_Associations => New_List (Opnd)));
Analyze_And_Resolve (N, Typ);
end Expand_N_Op_Not;
--------------------
-- Expand_N_Op_Or --
--------------------
procedure Expand_N_Op_Or (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
begin
Binary_Op_Validity_Checks (N);
if Is_Array_Type (Etype (N)) then
Expand_Boolean_Operator (N);
elsif Is_Boolean_Type (Etype (N)) then
Adjust_Condition (Left_Opnd (N));
Adjust_Condition (Right_Opnd (N));
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
elsif Is_Intrinsic_Subprogram (Entity (N)) then
Expand_Intrinsic_Call (N, Entity (N));
end if;
end Expand_N_Op_Or;
----------------------
-- Expand_N_Op_Plus --
----------------------
procedure Expand_N_Op_Plus (N : Node_Id) is
begin
Unary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
end Expand_N_Op_Plus;
---------------------
-- Expand_N_Op_Rem --
---------------------
procedure Expand_N_Op_Rem (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Left : Node_Id;
Right : Node_Id;
Lo : Uint;
Hi : Uint;
OK : Boolean;
Lneg : Boolean;
Rneg : Boolean;
-- Set if corresponding operand can be negative
pragma Unreferenced (Hi);
begin
Binary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
if Is_Integer_Type (Etype (N)) then
Apply_Divide_Checks (N);
-- All done if we don't have a REM any more, which can happen as a
-- result of overflow expansion in MINIMIZED or ELIMINATED modes.
if Nkind (N) /= N_Op_Rem then
return;
end if;
end if;
-- Proceed with expansion of REM
Left := Left_Opnd (N);
Right := Right_Opnd (N);
-- Apply optimization x rem 1 = 0. We don't really need that with gcc,
-- but it is useful with other back ends (e.g. AAMP), and is certainly
-- harmless.
if Is_Integer_Type (Etype (N))
and then Compile_Time_Known_Value (Right)
and then Expr_Value (Right) = Uint_1
then
-- Call Remove_Side_Effects to ensure that any side effects in the
-- ignored left operand (in particular function calls to user defined
-- functions) are properly executed.
Remove_Side_Effects (Left);
Rewrite (N, Make_Integer_Literal (Loc, 0));
Analyze_And_Resolve (N, Typ);
return;
end if;
-- Deal with annoying case of largest negative number remainder minus
-- one. Gigi may not handle this case correctly, because on some
-- targets, the mod value is computed using a divide instruction
-- which gives an overflow trap for this case.
-- It would be a bit more efficient to figure out which targets this
-- is really needed for, but in practice it is reasonable to do the
-- following special check in all cases, since it means we get a clearer
-- message, and also the overhead is minimal given that division is
-- expensive in any case.
-- In fact the check is quite easy, if the right operand is -1, then
-- the remainder is always 0, and we can just ignore the left operand
-- completely in this case.
Determine_Range (Right, OK, Lo, Hi, Assume_Valid => True);
Lneg := (not OK) or else Lo < 0;
Determine_Range (Left, OK, Lo, Hi, Assume_Valid => True);
Rneg := (not OK) or else Lo < 0;
-- We won't mess with trying to find out if the left operand can really
-- be the largest negative number (that's a pain in the case of private
-- types and this is really marginal). We will just assume that we need
-- the test if the left operand can be negative at all.
if Lneg and Rneg then
Rewrite (N,
Make_If_Expression (Loc,
Expressions => New_List (
Make_Op_Eq (Loc,
Left_Opnd => Duplicate_Subexpr (Right),
Right_Opnd =>
Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))),
Unchecked_Convert_To (Typ,
Make_Integer_Literal (Loc, Uint_0)),
Relocate_Node (N))));
Set_Analyzed (Next (Next (First (Expressions (N)))));
Analyze_And_Resolve (N, Typ);
end if;
end Expand_N_Op_Rem;
-----------------------------
-- Expand_N_Op_Rotate_Left --
-----------------------------
procedure Expand_N_Op_Rotate_Left (N : Node_Id) is
begin
Binary_Op_Validity_Checks (N);
end Expand_N_Op_Rotate_Left;
------------------------------
-- Expand_N_Op_Rotate_Right --
------------------------------
procedure Expand_N_Op_Rotate_Right (N : Node_Id) is
begin
Binary_Op_Validity_Checks (N);
end Expand_N_Op_Rotate_Right;
----------------------------
-- Expand_N_Op_Shift_Left --
----------------------------
procedure Expand_N_Op_Shift_Left (N : Node_Id) is
begin
Binary_Op_Validity_Checks (N);
end Expand_N_Op_Shift_Left;
-----------------------------
-- Expand_N_Op_Shift_Right --
-----------------------------
procedure Expand_N_Op_Shift_Right (N : Node_Id) is
begin
Binary_Op_Validity_Checks (N);
end Expand_N_Op_Shift_Right;
----------------------------------------
-- Expand_N_Op_Shift_Right_Arithmetic --
----------------------------------------
procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is
begin
Binary_Op_Validity_Checks (N);
end Expand_N_Op_Shift_Right_Arithmetic;
--------------------------
-- Expand_N_Op_Subtract --
--------------------------
procedure Expand_N_Op_Subtract (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
begin
Binary_Op_Validity_Checks (N);
-- Check for MINIMIZED/ELIMINATED overflow mode
if Minimized_Eliminated_Overflow_Check (N) then
Apply_Arithmetic_Overflow_Check (N);
return;
end if;
-- N - 0 = N for integer types
if Is_Integer_Type (Typ)
and then Compile_Time_Known_Value (Right_Opnd (N))
and then Expr_Value (Right_Opnd (N)) = 0
then
Rewrite (N, Left_Opnd (N));
return;
end if;
-- Arithmetic overflow checks for signed integer/fixed point types
if Is_Signed_Integer_Type (Typ)
or else
Is_Fixed_Point_Type (Typ)
then
Apply_Arithmetic_Overflow_Check (N);
-- VAX floating-point types case
elsif Vax_Float (Typ) then
Expand_Vax_Arith (N);
end if;
end Expand_N_Op_Subtract;
---------------------
-- Expand_N_Op_Xor --
---------------------
procedure Expand_N_Op_Xor (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
begin
Binary_Op_Validity_Checks (N);
if Is_Array_Type (Etype (N)) then
Expand_Boolean_Operator (N);
elsif Is_Boolean_Type (Etype (N)) then
Adjust_Condition (Left_Opnd (N));
Adjust_Condition (Right_Opnd (N));
Set_Etype (N, Standard_Boolean);
Adjust_Result_Type (N, Typ);
elsif Is_Intrinsic_Subprogram (Entity (N)) then
Expand_Intrinsic_Call (N, Entity (N));
end if;
end Expand_N_Op_Xor;
----------------------
-- Expand_N_Or_Else --
----------------------
procedure Expand_N_Or_Else (N : Node_Id)
renames Expand_Short_Circuit_Operator;
-----------------------------------
-- Expand_N_Qualified_Expression --
-----------------------------------
procedure Expand_N_Qualified_Expression (N : Node_Id) is
Operand : constant Node_Id := Expression (N);
Target_Type : constant Entity_Id := Entity (Subtype_Mark (N));
begin
-- Do validity check if validity checking operands
if Validity_Checks_On and then Validity_Check_Operands then
Ensure_Valid (Operand);
end if;
-- Apply possible constraint check
Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True);
if Do_Range_Check (Operand) then
Set_Do_Range_Check (Operand, False);
Generate_Range_Check (Operand, Target_Type, CE_Range_Check_Failed);
end if;
end Expand_N_Qualified_Expression;
------------------------------------
-- Expand_N_Quantified_Expression --
------------------------------------
-- We expand:
-- for all X in range => Cond
-- into:
-- T := True;
-- for X in range loop
-- if not Cond then
-- T := False;
-- exit;
-- end if;
-- end loop;
-- Similarly, an existentially quantified expression:
-- for some X in range => Cond
-- becomes:
-- T := False;
-- for X in range loop
-- if Cond then
-- T := True;
-- exit;
-- end if;
-- end loop;
-- In both cases, the iteration may be over a container in which case it is
-- given by an iterator specification, not a loop parameter specification.
procedure Expand_N_Quantified_Expression (N : Node_Id) is
Actions : constant List_Id := New_List;
For_All : constant Boolean := All_Present (N);
Iter_Spec : constant Node_Id := Iterator_Specification (N);
Loc : constant Source_Ptr := Sloc (N);
Loop_Spec : constant Node_Id := Loop_Parameter_Specification (N);
Cond : Node_Id;
Flag : Entity_Id;
Scheme : Node_Id;
Stmts : List_Id;
begin
-- Create the declaration of the flag which tracks the status of the
-- quantified expression. Generate:
-- Flag : Boolean := (True | False);
Flag := Make_Temporary (Loc, 'T', N);
Append_To (Actions,
Make_Object_Declaration (Loc,
Defining_Identifier => Flag,
Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
Expression =>
New_Occurrence_Of (Boolean_Literals (For_All), Loc)));
-- Construct the circuitry which tracks the status of the quantified
-- expression. Generate:
-- if [not] Cond then
-- Flag := (False | True);
-- exit;
-- end if;
Cond := Relocate_Node (Condition (N));
if For_All then
Cond := Make_Op_Not (Loc, Cond);
end if;
Stmts := New_List (
Make_Implicit_If_Statement (N,
Condition => Cond,
Then_Statements => New_List (
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Flag, Loc),
Expression =>
New_Occurrence_Of (Boolean_Literals (not For_All), Loc)),
Make_Exit_Statement (Loc))));
-- Build the loop equivalent of the quantified expression
if Present (Iter_Spec) then
Scheme :=
Make_Iteration_Scheme (Loc,
Iterator_Specification => Iter_Spec);
else
Scheme :=
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification => Loop_Spec);
end if;
Append_To (Actions,
Make_Loop_Statement (Loc,
Iteration_Scheme => Scheme,
Statements => Stmts,
End_Label => Empty));
-- Transform the quantified expression
Rewrite (N,
Make_Expression_With_Actions (Loc,
Expression => New_Occurrence_Of (Flag, Loc),
Actions => Actions));
Analyze_And_Resolve (N, Standard_Boolean);
end Expand_N_Quantified_Expression;
---------------------------------
-- Expand_N_Selected_Component --
---------------------------------
procedure Expand_N_Selected_Component (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Par : constant Node_Id := Parent (N);
P : constant Node_Id := Prefix (N);
Ptyp : Entity_Id := Underlying_Type (Etype (P));
Disc : Entity_Id;
New_N : Node_Id;
Dcon : Elmt_Id;
Dval : Node_Id;
function In_Left_Hand_Side (Comp : Node_Id) return Boolean;
-- Gigi needs a temporary for prefixes that depend on a discriminant,
-- unless the context of an assignment can provide size information.
-- Don't we have a general routine that does this???
function Is_Subtype_Declaration return Boolean;
-- The replacement of a discriminant reference by its value is required
-- if this is part of the initialization of an temporary generated by a
-- change of representation. This shows up as the construction of a
-- discriminant constraint for a subtype declared at the same point as
-- the entity in the prefix of the selected component. We recognize this
-- case when the context of the reference is:
-- subtype ST is T(Obj.D);
-- where the entity for Obj comes from source, and ST has the same sloc.
-----------------------
-- In_Left_Hand_Side --
-----------------------
function In_Left_Hand_Side (Comp : Node_Id) return Boolean is
begin
return (Nkind (Parent (Comp)) = N_Assignment_Statement
and then Comp = Name (Parent (Comp)))
or else (Present (Parent (Comp))
and then Nkind (Parent (Comp)) in N_Subexpr
and then In_Left_Hand_Side (Parent (Comp)));
end In_Left_Hand_Side;
-----------------------------
-- Is_Subtype_Declaration --
-----------------------------
function Is_Subtype_Declaration return Boolean is
Par : constant Node_Id := Parent (N);
begin
return
Nkind (Par) = N_Index_Or_Discriminant_Constraint
and then Nkind (Parent (Parent (Par))) = N_Subtype_Declaration
and then Comes_From_Source (Entity (Prefix (N)))
and then Sloc (Par) = Sloc (Entity (Prefix (N)));
end Is_Subtype_Declaration;
-- Start of processing for Expand_N_Selected_Component
begin
-- Insert explicit dereference if required
if Is_Access_Type (Ptyp) then
-- First set prefix type to proper access type, in case it currently
-- has a private (non-access) view of this type.
Set_Etype (P, Ptyp);
Insert_Explicit_Dereference (P);
Analyze_And_Resolve (P, Designated_Type (Ptyp));
if Ekind (Etype (P)) = E_Private_Subtype
and then Is_For_Access_Subtype (Etype (P))
then
Set_Etype (P, Base_Type (Etype (P)));
end if;
Ptyp := Etype (P);
end if;
-- Deal with discriminant check required
if Do_Discriminant_Check (N) then
-- Present the discriminant checking function to the backend, so that
-- it can inline the call to the function.
Add_Inlined_Body
(Discriminant_Checking_Func
(Original_Record_Component (Entity (Selector_Name (N)))));
-- Now reset the flag and generate the call
Set_Do_Discriminant_Check (N, False);
Generate_Discriminant_Check (N);
end if;
-- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
-- function, then additional actuals must be passed.
if Ada_Version >= Ada_2005
and then Is_Build_In_Place_Function_Call (P)
then
Make_Build_In_Place_Call_In_Anonymous_Context (P);
end if;
-- Gigi cannot handle unchecked conversions that are the prefix of a
-- selected component with discriminants. This must be checked during
-- expansion, because during analysis the type of the selector is not
-- known at the point the prefix is analyzed. If the conversion is the
-- target of an assignment, then we cannot force the evaluation.
if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion
and then Has_Discriminants (Etype (N))
and then not In_Left_Hand_Side (N)
then
Force_Evaluation (Prefix (N));
end if;
-- Remaining processing applies only if selector is a discriminant
if Ekind (Entity (Selector_Name (N))) = E_Discriminant then
-- If the selector is a discriminant of a constrained record type,
-- we may be able to rewrite the expression with the actual value
-- of the discriminant, a useful optimization in some cases.
if Is_Record_Type (Ptyp)
and then Has_Discriminants (Ptyp)
and then Is_Constrained (Ptyp)
then
-- Do this optimization for discrete types only, and not for
-- access types (access discriminants get us into trouble!)
if not Is_Discrete_Type (Etype (N)) then
null;
-- Don't do this on the left hand of an assignment statement.
-- Normally one would think that references like this would not
-- occur, but they do in generated code, and mean that we really
-- do want to assign the discriminant!
elsif Nkind (Par) = N_Assignment_Statement
and then Name (Par) = N
then
null;
-- Don't do this optimization for the prefix of an attribute or
-- the name of an object renaming declaration since these are
-- contexts where we do not want the value anyway.
elsif (Nkind (Par) = N_Attribute_Reference
and then Prefix (Par) = N)
or else Is_Renamed_Object (N)
then
null;
-- Don't do this optimization if we are within the code for a
-- discriminant check, since the whole point of such a check may
-- be to verify the condition on which the code below depends!
elsif Is_In_Discriminant_Check (N) then
null;
-- Green light to see if we can do the optimization. There is
-- still one condition that inhibits the optimization below but
-- now is the time to check the particular discriminant.
else
-- Loop through discriminants to find the matching discriminant
-- constraint to see if we can copy it.
Disc := First_Discriminant (Ptyp);
Dcon := First_Elmt (Discriminant_Constraint (Ptyp));
Discr_Loop : while Present (Dcon) loop
Dval := Node (Dcon);
-- Check if this is the matching discriminant and if the
-- discriminant value is simple enough to make sense to
-- copy. We don't want to copy complex expressions, and
-- indeed to do so can cause trouble (before we put in
-- this guard, a discriminant expression containing an
-- AND THEN was copied, causing problems for coverage
-- analysis tools).
-- However, if the reference is part of the initialization
-- code generated for an object declaration, we must use
-- the discriminant value from the subtype constraint,
-- because the selected component may be a reference to the
-- object being initialized, whose discriminant is not yet
-- set. This only happens in complex cases involving changes
-- or representation.
if Disc = Entity (Selector_Name (N))
and then (Is_Entity_Name (Dval)
or else Compile_Time_Known_Value (Dval)
or else Is_Subtype_Declaration)
then
-- Here we have the matching discriminant. Check for
-- the case of a discriminant of a component that is
-- constrained by an outer discriminant, which cannot
-- be optimized away.
if Denotes_Discriminant
(Dval, Check_Concurrent => True)
then
exit Discr_Loop;
elsif Nkind (Original_Node (Dval)) = N_Selected_Component
and then
Denotes_Discriminant
(Selector_Name (Original_Node (Dval)), True)
then
exit Discr_Loop;
-- Do not retrieve value if constraint is not static. It
-- is generally not useful, and the constraint may be a
-- rewritten outer discriminant in which case it is in
-- fact incorrect.
elsif Is_Entity_Name (Dval)
and then Nkind (Parent (Entity (Dval))) =
N_Object_Declaration
and then Present (Expression (Parent (Entity (Dval))))
and then
not Is_Static_Expression
(Expression (Parent (Entity (Dval))))
then
exit Discr_Loop;
-- In the context of a case statement, the expression may
-- have the base type of the discriminant, and we need to
-- preserve the constraint to avoid spurious errors on
-- missing cases.
elsif Nkind (Parent (N)) = N_Case_Statement
and then Etype (Dval) /= Etype (Disc)
then
Rewrite (N,
Make_Qualified_Expression (Loc,
Subtype_Mark =>
New_Occurrence_Of (Etype (Disc), Loc),
Expression =>
New_Copy_Tree (Dval)));
Analyze_And_Resolve (N, Etype (Disc));
-- In case that comes out as a static expression,
-- reset it (a selected component is never static).
Set_Is_Static_Expression (N, False);
return;
-- Otherwise we can just copy the constraint, but the
-- result is certainly not static! In some cases the
-- discriminant constraint has been analyzed in the
-- context of the original subtype indication, but for
-- itypes the constraint might not have been analyzed
-- yet, and this must be done now.
else
Rewrite (N, New_Copy_Tree (Dval));
Analyze_And_Resolve (N);
Set_Is_Static_Expression (N, False);
return;
end if;
end if;
Next_Elmt (Dcon);
Next_Discriminant (Disc);
end loop Discr_Loop;
-- Note: the above loop should always find a matching
-- discriminant, but if it does not, we just missed an
-- optimization due to some glitch (perhaps a previous
-- error), so ignore.
end if;
end if;
-- The only remaining processing is in the case of a discriminant of
-- a concurrent object, where we rewrite the prefix to denote the
-- corresponding record type. If the type is derived and has renamed
-- discriminants, use corresponding discriminant, which is the one
-- that appears in the corresponding record.
if not Is_Concurrent_Type (Ptyp) then
return;
end if;
Disc := Entity (Selector_Name (N));
if Is_Derived_Type (Ptyp)
and then Present (Corresponding_Discriminant (Disc))
then
Disc := Corresponding_Discriminant (Disc);
end if;
New_N :=
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (Corresponding_Record_Type (Ptyp),
New_Copy_Tree (P)),
Selector_Name => Make_Identifier (Loc, Chars (Disc)));
Rewrite (N, New_N);
Analyze (N);
end if;
-- Set Atomic_Sync_Required if necessary for atomic component
if Nkind (N) = N_Selected_Component then
declare
E : constant Entity_Id := Entity (Selector_Name (N));
Set : Boolean;
begin
-- If component is atomic, but type is not, setting depends on
-- disable/enable state for the component.
if Is_Atomic (E) and then not Is_Atomic (Etype (E)) then
Set := not Atomic_Synchronization_Disabled (E);
-- If component is not atomic, but its type is atomic, setting
-- depends on disable/enable state for the type.
elsif not Is_Atomic (E) and then Is_Atomic (Etype (E)) then
Set := not Atomic_Synchronization_Disabled (Etype (E));
-- If both component and type are atomic, we disable if either
-- component or its type have sync disabled.
elsif Is_Atomic (E) and then Is_Atomic (Etype (E)) then
Set := (not Atomic_Synchronization_Disabled (E))
and then
(not Atomic_Synchronization_Disabled (Etype (E)));
else
Set := False;
end if;
-- Set flag if required
if Set then
Activate_Atomic_Synchronization (N);
end if;
end;
end if;
end Expand_N_Selected_Component;
--------------------
-- Expand_N_Slice --
--------------------
procedure Expand_N_Slice (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Pfx : constant Node_Id := Prefix (N);
Ptp : Entity_Id := Etype (Pfx);
function Is_Procedure_Actual (N : Node_Id) return Boolean;
-- Check whether the argument is an actual for a procedure call, in
-- which case the expansion of a bit-packed slice is deferred until the
-- call itself is expanded. The reason this is required is that we might
-- have an IN OUT or OUT parameter, and the copy out is essential, and
-- that copy out would be missed if we created a temporary here in
-- Expand_N_Slice. Note that we don't bother to test specifically for an
-- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
-- is harmless to defer expansion in the IN case, since the call
-- processing will still generate the appropriate copy in operation,
-- which will take care of the slice.
procedure Make_Temporary_For_Slice;
-- Create a named variable for the value of the slice, in cases where
-- the back-end cannot handle it properly, e.g. when packed types or
-- unaligned slices are involved.
-------------------------
-- Is_Procedure_Actual --
-------------------------
function Is_Procedure_Actual (N : Node_Id) return Boolean is
Par : Node_Id := Parent (N);
begin
loop
-- If our parent is a procedure call we can return
if Nkind (Par) = N_Procedure_Call_Statement then
return True;
-- If our parent is a type conversion, keep climbing the tree,
-- since a type conversion can be a procedure actual. Also keep
-- climbing if parameter association or a qualified expression,
-- since these are additional cases that do can appear on
-- procedure actuals.
elsif Nkind_In (Par, N_Type_Conversion,
N_Parameter_Association,
N_Qualified_Expression)
then
Par := Parent (Par);
-- Any other case is not what we are looking for
else
return False;
end if;
end loop;
end Is_Procedure_Actual;
------------------------------
-- Make_Temporary_For_Slice --
------------------------------
procedure Make_Temporary_For_Slice is
Decl : Node_Id;
Ent : constant Entity_Id := Make_Temporary (Loc, 'T', N);
begin
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Object_Definition => New_Occurrence_Of (Typ, Loc));
Set_No_Initialization (Decl);
Insert_Actions (N, New_List (
Decl,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Ent, Loc),
Expression => Relocate_Node (N))));
Rewrite (N, New_Occurrence_Of (Ent, Loc));
Analyze_And_Resolve (N, Typ);
end Make_Temporary_For_Slice;
-- Start of processing for Expand_N_Slice
begin
-- Special handling for access types
if Is_Access_Type (Ptp) then
Ptp := Designated_Type (Ptp);
Rewrite (Pfx,
Make_Explicit_Dereference (Sloc (N),
Prefix => Relocate_Node (Pfx)));
Analyze_And_Resolve (Pfx, Ptp);
end if;
-- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
-- function, then additional actuals must be passed.
if Ada_Version >= Ada_2005
and then Is_Build_In_Place_Function_Call (Pfx)
then
Make_Build_In_Place_Call_In_Anonymous_Context (Pfx);
end if;
-- The remaining case to be handled is packed slices. We can leave
-- packed slices as they are in the following situations:
-- 1. Right or left side of an assignment (we can handle this
-- situation correctly in the assignment statement expansion).
-- 2. Prefix of indexed component (the slide is optimized away in this
-- case, see the start of Expand_N_Slice.)
-- 3. Object renaming declaration, since we want the name of the
-- slice, not the value.
-- 4. Argument to procedure call, since copy-in/copy-out handling may
-- be required, and this is handled in the expansion of call
-- itself.
-- 5. Prefix of an address attribute (this is an error which is caught
-- elsewhere, and the expansion would interfere with generating the
-- error message).
if not Is_Packed (Typ) then
-- Apply transformation for actuals of a function call, where
-- Expand_Actuals is not used.
if Nkind (Parent (N)) = N_Function_Call
and then Is_Possibly_Unaligned_Slice (N)
then
Make_Temporary_For_Slice;
end if;
elsif Nkind (Parent (N)) = N_Assignment_Statement
or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement
and then Parent (N) = Name (Parent (Parent (N))))
then
return;
elsif Nkind (Parent (N)) = N_Indexed_Component
or else Is_Renamed_Object (N)
or else Is_Procedure_Actual (N)
then
return;
elsif Nkind (Parent (N)) = N_Attribute_Reference
and then Attribute_Name (Parent (N)) = Name_Address
then
return;
else
Make_Temporary_For_Slice;
end if;
end Expand_N_Slice;
------------------------------
-- Expand_N_Type_Conversion --
------------------------------
procedure Expand_N_Type_Conversion (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Operand : constant Node_Id := Expression (N);
Target_Type : constant Entity_Id := Etype (N);
Operand_Type : Entity_Id := Etype (Operand);
procedure Handle_Changed_Representation;
-- This is called in the case of record and array type conversions to
-- see if there is a change of representation to be handled. Change of
-- representation is actually handled at the assignment statement level,
-- and what this procedure does is rewrite node N conversion as an
-- assignment to temporary. If there is no change of representation,
-- then the conversion node is unchanged.
procedure Raise_Accessibility_Error;
-- Called when we know that an accessibility check will fail. Rewrites
-- node N to an appropriate raise statement and outputs warning msgs.
-- The Etype of the raise node is set to Target_Type.
procedure Real_Range_Check;
-- Handles generation of range check for real target value
function Has_Extra_Accessibility (Id : Entity_Id) return Boolean;
-- True iff Present (Effective_Extra_Accessibility (Id)) successfully
-- evaluates to True.
-----------------------------------
-- Handle_Changed_Representation --
-----------------------------------
procedure Handle_Changed_Representation is
Temp : Entity_Id;
Decl : Node_Id;
Odef : Node_Id;
Disc : Node_Id;
N_Ix : Node_Id;
Cons : List_Id;
begin
-- Nothing else to do if no change of representation
if Same_Representation (Operand_Type, Target_Type) then
return;
-- The real change of representation work is done by the assignment
-- statement processing. So if this type conversion is appearing as
-- the expression of an assignment statement, nothing needs to be
-- done to the conversion.
elsif Nkind (Parent (N)) = N_Assignment_Statement then
return;
-- Otherwise we need to generate a temporary variable, and do the
-- change of representation assignment into that temporary variable.
-- The conversion is then replaced by a reference to this variable.
else
Cons := No_List;
-- If type is unconstrained we have to add a constraint, copied
-- from the actual value of the left hand side.
if not Is_Constrained (Target_Type) then
if Has_Discriminants (Operand_Type) then
Disc := First_Discriminant (Operand_Type);
if Disc /= First_Stored_Discriminant (Operand_Type) then
Disc := First_Stored_Discriminant (Operand_Type);
end if;
Cons := New_List;
while Present (Disc) loop
Append_To (Cons,
Make_Selected_Component (Loc,
Prefix =>
Duplicate_Subexpr_Move_Checks (Operand),
Selector_Name =>
Make_Identifier (Loc, Chars (Disc))));
Next_Discriminant (Disc);
end loop;
elsif Is_Array_Type (Operand_Type) then
N_Ix := First_Index (Target_Type);
Cons := New_List;
for J in 1 .. Number_Dimensions (Operand_Type) loop
-- We convert the bounds explicitly. We use an unchecked
-- conversion because bounds checks are done elsewhere.
Append_To (Cons,
Make_Range (Loc,
Low_Bound =>
Unchecked_Convert_To (Etype (N_Ix),
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr_No_Checks
(Operand, Name_Req => True),
Attribute_Name => Name_First,
Expressions => New_List (
Make_Integer_Literal (Loc, J)))),
High_Bound =>
Unchecked_Convert_To (Etype (N_Ix),
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr_No_Checks
(Operand, Name_Req => True),
Attribute_Name => Name_Last,
Expressions => New_List (
Make_Integer_Literal (Loc, J))))));
Next_Index (N_Ix);
end loop;
end if;
end if;
Odef := New_Occurrence_Of (Target_Type, Loc);
if Present (Cons) then
Odef :=
Make_Subtype_Indication (Loc,
Subtype_Mark => Odef,
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => Cons));
end if;
Temp := Make_Temporary (Loc, 'C');
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_Definition => Odef);
Set_No_Initialization (Decl, True);
-- Insert required actions. It is essential to suppress checks
-- since we have suppressed default initialization, which means
-- that the variable we create may have no discriminants.
Insert_Actions (N,
New_List (
Decl,
Make_Assignment_Statement (Loc,
Name => New_Occurrence_Of (Temp, Loc),
Expression => Relocate_Node (N))),
Suppress => All_Checks);
Rewrite (N, New_Occurrence_Of (Temp, Loc));
return;
end if;
end Handle_Changed_Representation;
-------------------------------
-- Raise_Accessibility_Error --
-------------------------------
procedure Raise_Accessibility_Error is
begin
Rewrite (N,
Make_Raise_Program_Error (Sloc (N),
Reason => PE_Accessibility_Check_Failed));
Set_Etype (N, Target_Type);
Error_Msg_N
("??accessibility check failure", N);
Error_Msg_NE
("\??& will be raised at run time", N, Standard_Program_Error);
end Raise_Accessibility_Error;
----------------------
-- Real_Range_Check --
----------------------
-- Case of conversions to floating-point or fixed-point. If range checks
-- are enabled and the target type has a range constraint, we convert:
-- typ (x)
-- to
-- Tnn : typ'Base := typ'Base (x);
-- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
-- Tnn
-- This is necessary when there is a conversion of integer to float or
-- to fixed-point to ensure that the correct checks are made. It is not
-- necessary for float to float where it is enough to simply set the
-- Do_Range_Check flag.
procedure Real_Range_Check is
Btyp : constant Entity_Id := Base_Type (Target_Type);
Lo : constant Node_Id := Type_Low_Bound (Target_Type);
Hi : constant Node_Id := Type_High_Bound (Target_Type);
Xtyp : constant Entity_Id := Etype (Operand);
Conv : Node_Id;
Tnn : Entity_Id;
begin
-- Nothing to do if conversion was rewritten
if Nkind (N) /= N_Type_Conversion then
return;
end if;
-- Nothing to do if range checks suppressed, or target has the same
-- range as the base type (or is the base type).
if Range_Checks_Suppressed (Target_Type)
or else (Lo = Type_Low_Bound (Btyp)
and then
Hi = Type_High_Bound (Btyp))
then
return;
end if;
-- Nothing to do if expression is an entity on which checks have been
-- suppressed.
if Is_Entity_Name (Operand)
and then Range_Checks_Suppressed (Entity (Operand))
then
return;
end if;
-- Nothing to do if bounds are all static and we can tell that the
-- expression is within the bounds of the target. Note that if the
-- operand is of an unconstrained floating-point type, then we do
-- not trust it to be in range (might be infinite)
declare
S_Lo : constant Node_Id := Type_Low_Bound (Xtyp);
S_Hi : constant Node_Id := Type_High_Bound (Xtyp);
begin
if (not Is_Floating_Point_Type (Xtyp)
or else Is_Constrained (Xtyp))
and then Compile_Time_Known_Value (S_Lo)
and then Compile_Time_Known_Value (S_Hi)
and then Compile_Time_Known_Value (Hi)
and then Compile_Time_Known_Value (Lo)
then
declare
D_Lov : constant Ureal := Expr_Value_R (Lo);
D_Hiv : constant Ureal := Expr_Value_R (Hi);
S_Lov : Ureal;
S_Hiv : Ureal;
begin
if Is_Real_Type (Xtyp) then
S_Lov := Expr_Value_R (S_Lo);
S_Hiv := Expr_Value_R (S_Hi);
else
S_Lov := UR_From_Uint (Expr_Value (S_Lo));
S_Hiv := UR_From_Uint (Expr_Value (S_Hi));
end if;
if D_Hiv > D_Lov
and then S_Lov >= D_Lov
and then S_Hiv <= D_Hiv
then
Set_Do_Range_Check (Operand, False);
return;
end if;
end;
end if;
end;
-- For float to float conversions, we are done
if Is_Floating_Point_Type (Xtyp)
and then
Is_Floating_Point_Type (Btyp)
then
return;
end if;
-- Otherwise rewrite the conversion as described above
Conv := Relocate_Node (N);
Rewrite (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc));
Set_Etype (Conv, Btyp);
-- Enable overflow except for case of integer to float conversions,
-- where it is never required, since we can never have overflow in
-- this case.
if not Is_Integer_Type (Etype (Operand)) then
Enable_Overflow_Check (Conv);
end if;
Tnn := Make_Temporary (Loc, 'T', Conv);
Insert_Actions (N, New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => Tnn,
Object_Definition => New_Occurrence_Of (Btyp, Loc),
Constant_Present => True,
Expression => Conv),
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Or_Else (Loc,
Left_Opnd =>
Make_Op_Lt (Loc,
Left_Opnd => New_Occurrence_Of (Tnn, Loc),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix =>
New_Occurrence_Of (Target_Type, Loc))),
Right_Opnd =>
Make_Op_Gt (Loc,
Left_Opnd => New_Occurrence_Of (Tnn, Loc),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix =>
New_Occurrence_Of (Target_Type, Loc)))),
Reason => CE_Range_Check_Failed)));
Rewrite (N, New_Occurrence_Of (Tnn, Loc));
Analyze_And_Resolve (N, Btyp);
end Real_Range_Check;
-----------------------------
-- Has_Extra_Accessibility --
-----------------------------
-- Returns true for a formal of an anonymous access type or for
-- an Ada 2012-style stand-alone object of an anonymous access type.
function Has_Extra_Accessibility (Id : Entity_Id) return Boolean is
begin
if Is_Formal (Id) or else Ekind_In (Id, E_Constant, E_Variable) then
return Present (Effective_Extra_Accessibility (Id));
else
return False;
end if;
end Has_Extra_Accessibility;
-- Start of processing for Expand_N_Type_Conversion
begin
-- Nothing at all to do if conversion is to the identical type so remove
-- the conversion completely, it is useless, except that it may carry
-- an Assignment_OK attribute, which must be propagated to the operand.
if Operand_Type = Target_Type then
if Assignment_OK (N) then
Set_Assignment_OK (Operand);
end if;
Rewrite (N, Relocate_Node (Operand));
goto Done;
end if;
-- Nothing to do if this is the second argument of read. This is a
-- "backwards" conversion that will be handled by the specialized code
-- in attribute processing.
if Nkind (Parent (N)) = N_Attribute_Reference
and then Attribute_Name (Parent (N)) = Name_Read
and then Next (First (Expressions (Parent (N)))) = N
then
goto Done;
end if;
-- Check for case of converting to a type that has an invariant
-- associated with it. This required an invariant check. We convert
-- typ (expr)
-- into
-- do invariant_check (typ (expr)) in typ (expr);
-- using Duplicate_Subexpr to avoid multiple side effects
-- Note: the Comes_From_Source check, and then the resetting of this
-- flag prevents what would otherwise be an infinite recursion.
if Has_Invariants (Target_Type)
and then Present (Invariant_Procedure (Target_Type))
and then Comes_From_Source (N)
then
Set_Comes_From_Source (N, False);
Rewrite (N,
Make_Expression_With_Actions (Loc,
Actions => New_List (
Make_Invariant_Call (Duplicate_Subexpr (N))),
Expression => Duplicate_Subexpr_No_Checks (N)));
Analyze_And_Resolve (N, Target_Type);
goto Done;
end if;
-- Here if we may need to expand conversion
-- If the operand of the type conversion is an arithmetic operation on
-- signed integers, and the based type of the signed integer type in
-- question is smaller than Standard.Integer, we promote both of the
-- operands to type Integer.
-- For example, if we have
-- target-type (opnd1 + opnd2)
-- and opnd1 and opnd2 are of type short integer, then we rewrite
-- this as:
-- target-type (integer(opnd1) + integer(opnd2))
-- We do this because we are always allowed to compute in a larger type
-- if we do the right thing with the result, and in this case we are
-- going to do a conversion which will do an appropriate check to make
-- sure that things are in range of the target type in any case. This
-- avoids some unnecessary intermediate overflows.
-- We might consider a similar transformation in the case where the
-- target is a real type or a 64-bit integer type, and the operand
-- is an arithmetic operation using a 32-bit integer type. However,
-- we do not bother with this case, because it could cause significant
-- inefficiencies on 32-bit machines. On a 64-bit machine it would be
-- much cheaper, but we don't want different behavior on 32-bit and
-- 64-bit machines. Note that the exclusion of the 64-bit case also
-- handles the configurable run-time cases where 64-bit arithmetic
-- may simply be unavailable.
-- Note: this circuit is partially redundant with respect to the circuit
-- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in
-- the processing here. Also we still need the Checks circuit, since we
-- have to be sure not to generate junk overflow checks in the first
-- place, since it would be trick to remove them here!
if Integer_Promotion_Possible (N) then
-- All conditions met, go ahead with transformation
declare
Opnd : Node_Id;
L, R : Node_Id;
begin
R :=
Make_Type_Conversion (Loc,
Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
Expression => Relocate_Node (Right_Opnd (Operand)));
Opnd := New_Op_Node (Nkind (Operand), Loc);
Set_Right_Opnd (Opnd, R);
if Nkind (Operand) in N_Binary_Op then
L :=
Make_Type_Conversion (Loc,
Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
Expression => Relocate_Node (Left_Opnd (Operand)));
Set_Left_Opnd (Opnd, L);
end if;
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => Relocate_Node (Subtype_Mark (N)),
Expression => Opnd));
Analyze_And_Resolve (N, Target_Type);
goto Done;
end;
end if;
-- Do validity check if validity checking operands
if Validity_Checks_On
and then Validity_Check_Operands
then
Ensure_Valid (Operand);
end if;
-- Special case of converting from non-standard boolean type
if Is_Boolean_Type (Operand_Type)
and then (Nonzero_Is_True (Operand_Type))
then
Adjust_Condition (Operand);
Set_Etype (Operand, Standard_Boolean);
Operand_Type := Standard_Boolean;
end if;
-- Case of converting to an access type
if Is_Access_Type (Target_Type) then
-- Apply an accessibility check when the conversion operand is an
-- access parameter (or a renaming thereof), unless conversion was
-- expanded from an Unchecked_ or Unrestricted_Access attribute.
-- Note that other checks may still need to be applied below (such
-- as tagged type checks).
if Is_Entity_Name (Operand)
and then Has_Extra_Accessibility (Entity (Operand))
and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type
and then (Nkind (Original_Node (N)) /= N_Attribute_Reference
or else Attribute_Name (Original_Node (N)) = Name_Access)
then
Apply_Accessibility_Check
(Operand, Target_Type, Insert_Node => Operand);
-- If the level of the operand type is statically deeper than the
-- level of the target type, then force Program_Error. Note that this
-- can only occur for cases where the attribute is within the body of
-- an instantiation (otherwise the conversion will already have been
-- rejected as illegal). Note: warnings are issued by the analyzer
-- for the instance cases.
elsif In_Instance_Body
and then Type_Access_Level (Operand_Type) >
Type_Access_Level (Target_Type)
then
Raise_Accessibility_Error;
-- When the operand is a selected access discriminant the check needs
-- to be made against the level of the object denoted by the prefix
-- of the selected name. Force Program_Error for this case as well
-- (this accessibility violation can only happen if within the body
-- of an instantiation).
elsif In_Instance_Body
and then Ekind (Operand_Type) = E_Anonymous_Access_Type
and then Nkind (Operand) = N_Selected_Component
and then Object_Access_Level (Operand) >
Type_Access_Level (Target_Type)
then
Raise_Accessibility_Error;
goto Done;
end if;
end if;
-- Case of conversions of tagged types and access to tagged types
-- When needed, that is to say when the expression is class-wide, Add
-- runtime a tag check for (strict) downward conversion by using the
-- membership test, generating:
-- [constraint_error when Operand not in Target_Type'Class]
-- or in the access type case
-- [constraint_error
-- when Operand /= null
-- and then Operand.all not in
-- Designated_Type (Target_Type)'Class]
if (Is_Access_Type (Target_Type)
and then Is_Tagged_Type (Designated_Type (Target_Type)))
or else Is_Tagged_Type (Target_Type)
then
-- Do not do any expansion in the access type case if the parent is a
-- renaming, since this is an error situation which will be caught by
-- Sem_Ch8, and the expansion can interfere with this error check.
if Is_Access_Type (Target_Type) and then Is_Renamed_Object (N) then
goto Done;
end if;
-- Otherwise, proceed with processing tagged conversion
Tagged_Conversion : declare
Actual_Op_Typ : Entity_Id;
Actual_Targ_Typ : Entity_Id;
Make_Conversion : Boolean := False;
Root_Op_Typ : Entity_Id;
procedure Make_Tag_Check (Targ_Typ : Entity_Id);
-- Create a membership check to test whether Operand is a member
-- of Targ_Typ. If the original Target_Type is an access, include
-- a test for null value. The check is inserted at N.
--------------------
-- Make_Tag_Check --
--------------------
procedure Make_Tag_Check (Targ_Typ : Entity_Id) is
Cond : Node_Id;
begin
-- Generate:
-- [Constraint_Error
-- when Operand /= null
-- and then Operand.all not in Targ_Typ]
if Is_Access_Type (Target_Type) then
Cond :=
Make_And_Then (Loc,
Left_Opnd =>
Make_Op_Ne (Loc,
Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
Right_Opnd => Make_Null (Loc)),
Right_Opnd =>
Make_Not_In (Loc,
Left_Opnd =>
Make_Explicit_Dereference (Loc,
Prefix => Duplicate_Subexpr_No_Checks (Operand)),
Right_Opnd => New_Reference_To (Targ_Typ, Loc)));
-- Generate:
-- [Constraint_Error when Operand not in Targ_Typ]
else
Cond :=
Make_Not_In (Loc,
Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
Right_Opnd => New_Reference_To (Targ_Typ, Loc));
end if;
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition => Cond,
Reason => CE_Tag_Check_Failed));
end Make_Tag_Check;
-- Start of processing for Tagged_Conversion
begin
-- Handle entities from the limited view
if Is_Access_Type (Operand_Type) then
Actual_Op_Typ :=
Available_View (Designated_Type (Operand_Type));
else
Actual_Op_Typ := Operand_Type;
end if;
if Is_Access_Type (Target_Type) then
Actual_Targ_Typ :=
Available_View (Designated_Type (Target_Type));
else
Actual_Targ_Typ := Target_Type;
end if;
Root_Op_Typ := Root_Type (Actual_Op_Typ);
-- Ada 2005 (AI-251): Handle interface type conversion
if Is_Interface (Actual_Op_Typ) then
Expand_Interface_Conversion (N, Is_Static => False);
goto Done;
end if;
if not Tag_Checks_Suppressed (Actual_Targ_Typ) then
-- Create a runtime tag check for a downward class-wide type
-- conversion.
if Is_Class_Wide_Type (Actual_Op_Typ)
and then Actual_Op_Typ /= Actual_Targ_Typ
and then Root_Op_Typ /= Actual_Targ_Typ
and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ,
Use_Full_View => True)
then
Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ));
Make_Conversion := True;
end if;
-- AI05-0073: If the result subtype of the function is defined
-- by an access_definition designating a specific tagged type
-- T, a check is made that the result value is null or the tag
-- of the object designated by the result value identifies T.
-- Constraint_Error is raised if this check fails.
if Nkind (Parent (N)) = N_Simple_Return_Statement then
declare
Func : Entity_Id;
Func_Typ : Entity_Id;
begin
-- Climb scope stack looking for the enclosing function
Func := Current_Scope;
while Present (Func)
and then Ekind (Func) /= E_Function
loop
Func := Scope (Func);
end loop;
-- The function's return subtype must be defined using
-- an access definition.
if Nkind (Result_Definition (Parent (Func))) =
N_Access_Definition
then
Func_Typ := Directly_Designated_Type (Etype (Func));
-- The return subtype denotes a specific tagged type,
-- in other words, a non class-wide type.
if Is_Tagged_Type (Func_Typ)
and then not Is_Class_Wide_Type (Func_Typ)
then
Make_Tag_Check (Actual_Targ_Typ);
Make_Conversion := True;
end if;
end if;
end;
end if;
-- We have generated a tag check for either a class-wide type
-- conversion or for AI05-0073.
if Make_Conversion then
declare
Conv : Node_Id;
begin
Conv :=
Make_Unchecked_Type_Conversion (Loc,
Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
Expression => Relocate_Node (Expression (N)));
Rewrite (N, Conv);
Analyze_And_Resolve (N, Target_Type);
end;
end if;
end if;
end Tagged_Conversion;
-- Case of other access type conversions
elsif Is_Access_Type (Target_Type) then
Apply_Constraint_Check (Operand, Target_Type);
-- Case of conversions from a fixed-point type
-- These conversions require special expansion and processing, found in
-- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
-- since from a semantic point of view, these are simple integer
-- conversions, which do not need further processing.
elsif Is_Fixed_Point_Type (Operand_Type)
and then not Conversion_OK (N)
then
-- We should never see universal fixed at this case, since the
-- expansion of the constituent divide or multiply should have
-- eliminated the explicit mention of universal fixed.
pragma Assert (Operand_Type /= Universal_Fixed);
-- Check for special case of the conversion to universal real that
-- occurs as a result of the use of a round attribute. In this case,
-- the real type for the conversion is taken from the target type of
-- the Round attribute and the result must be marked as rounded.
if Target_Type = Universal_Real
and then Nkind (Parent (N)) = N_Attribute_Reference
and then Attribute_Name (Parent (N)) = Name_Round
then
Set_Rounded_Result (N);
Set_Etype (N, Etype (Parent (N)));
end if;
-- Otherwise do correct fixed-conversion, but skip these if the
-- Conversion_OK flag is set, because from a semantic point of view
-- these are simple integer conversions needing no further processing
-- (the backend will simply treat them as integers).
if not Conversion_OK (N) then
if Is_Fixed_Point_Type (Etype (N)) then
Expand_Convert_Fixed_To_Fixed (N);
Real_Range_Check;
elsif Is_Integer_Type (Etype (N)) then
Expand_Convert_Fixed_To_Integer (N);
else
pragma Assert (Is_Floating_Point_Type (Etype (N)));
Expand_Convert_Fixed_To_Float (N);
Real_Range_Check;
end if;
end if;
-- Case of conversions to a fixed-point type
-- These conversions require special expansion and processing, found in
-- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
-- since from a semantic point of view, these are simple integer
-- conversions, which do not need further processing.
elsif Is_Fixed_Point_Type (Target_Type)
and then not Conversion_OK (N)
then
if Is_Integer_Type (Operand_Type) then
Expand_Convert_Integer_To_Fixed (N);
Real_Range_Check;
else
pragma Assert (Is_Floating_Point_Type (Operand_Type));
Expand_Convert_Float_To_Fixed (N);
Real_Range_Check;
end if;
-- Case of float-to-integer conversions
-- We also handle float-to-fixed conversions with Conversion_OK set
-- since semantically the fixed-point target is treated as though it
-- were an integer in such cases.
elsif Is_Floating_Point_Type (Operand_Type)
and then
(Is_Integer_Type (Target_Type)
or else
(Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N)))
then
-- One more check here, gcc is still not able to do conversions of
-- this type with proper overflow checking, and so gigi is doing an
-- approximation of what is required by doing floating-point compares
-- with the end-point. But that can lose precision in some cases, and
-- give a wrong result. Converting the operand to Universal_Real is
-- helpful, but still does not catch all cases with 64-bit integers
-- on targets with only 64-bit floats.
-- The above comment seems obsoleted by Apply_Float_Conversion_Check
-- Can this code be removed ???
if Do_Range_Check (Operand) then
Rewrite (Operand,
Make_Type_Conversion (Loc,
Subtype_Mark =>
New_Occurrence_Of (Universal_Real, Loc),
Expression =>
Relocate_Node (Operand)));
Set_Etype (Operand, Universal_Real);
Enable_Range_Check (Operand);
Set_Do_Range_Check (Expression (Operand), False);
end if;
-- Case of array conversions
-- Expansion of array conversions, add required length/range checks but
-- only do this if there is no change of representation. For handling of
-- this case, see Handle_Changed_Representation.
elsif Is_Array_Type (Target_Type) then
if Is_Constrained (Target_Type) then
Apply_Length_Check (Operand, Target_Type);
else
Apply_Range_Check (Operand, Target_Type);
end if;
Handle_Changed_Representation;
-- Case of conversions of discriminated types
-- Add required discriminant checks if target is constrained. Again this
-- change is skipped if we have a change of representation.
elsif Has_Discriminants (Target_Type)
and then Is_Constrained (Target_Type)
then
Apply_Discriminant_Check (Operand, Target_Type);
Handle_Changed_Representation;
-- Case of all other record conversions. The only processing required
-- is to check for a change of representation requiring the special
-- assignment processing.
elsif Is_Record_Type (Target_Type) then
-- Ada 2005 (AI-216): Program_Error is raised when converting from
-- a derived Unchecked_Union type to an unconstrained type that is
-- not Unchecked_Union if the operand lacks inferable discriminants.
if Is_Derived_Type (Operand_Type)
and then Is_Unchecked_Union (Base_Type (Operand_Type))
and then not Is_Constrained (Target_Type)
and then not Is_Unchecked_Union (Base_Type (Target_Type))
and then not Has_Inferable_Discriminants (Operand)
then
-- To prevent Gigi from generating illegal code, we generate a
-- Program_Error node, but we give it the target type of the
-- conversion (is this requirement documented somewhere ???)
declare
PE : constant Node_Id := Make_Raise_Program_Error (Loc,
Reason => PE_Unchecked_Union_Restriction);
begin
Set_Etype (PE, Target_Type);
Rewrite (N, PE);
end;
else
Handle_Changed_Representation;
end if;
-- Case of conversions of enumeration types
elsif Is_Enumeration_Type (Target_Type) then
-- Special processing is required if there is a change of
-- representation (from enumeration representation clauses).
if not Same_Representation (Target_Type, Operand_Type) then
-- Convert: x(y) to x'val (ytyp'val (y))
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Target_Type, Loc),
Attribute_Name => Name_Val,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Operand_Type, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (Operand)))));
Analyze_And_Resolve (N, Target_Type);
end if;
-- Case of conversions to floating-point
elsif Is_Floating_Point_Type (Target_Type) then
Real_Range_Check;
end if;
-- At this stage, either the conversion node has been transformed into
-- some other equivalent expression, or left as a conversion that can be
-- handled by Gigi, in the following cases:
-- Conversions with no change of representation or type
-- Numeric conversions involving integer, floating- and fixed-point
-- values. Fixed-point values are allowed only if Conversion_OK is
-- set, i.e. if the fixed-point values are to be treated as integers.
-- No other conversions should be passed to Gigi
-- Check: are these rules stated in sinfo??? if so, why restate here???
-- The only remaining step is to generate a range check if we still have
-- a type conversion at this stage and Do_Range_Check is set. For now we
-- do this only for conversions of discrete types.
if Nkind (N) = N_Type_Conversion
and then Is_Discrete_Type (Etype (N))
then
declare
Expr : constant Node_Id := Expression (N);
Ftyp : Entity_Id;
Ityp : Entity_Id;
begin
if Do_Range_Check (Expr)
and then Is_Discrete_Type (Etype (Expr))
then
Set_Do_Range_Check (Expr, False);
-- Before we do a range check, we have to deal with treating a
-- fixed-point operand as an integer. The way we do this is
-- simply to do an unchecked conversion to an appropriate
-- integer type large enough to hold the result.
-- This code is not active yet, because we are only dealing
-- with discrete types so far ???
if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer
and then Treat_Fixed_As_Integer (Expr)
then
Ftyp := Base_Type (Etype (Expr));
if Esize (Ftyp) >= Esize (Standard_Integer) then
Ityp := Standard_Long_Long_Integer;
else
Ityp := Standard_Integer;
end if;
Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr));
end if;
-- Reset overflow flag, since the range check will include
-- dealing with possible overflow, and generate the check. If
-- Address is either a source type or target type, suppress
-- range check to avoid typing anomalies when it is a visible
-- integer type.
Set_Do_Overflow_Check (N, False);
if not Is_Descendent_Of_Address (Etype (Expr))
and then not Is_Descendent_Of_Address (Target_Type)
then
Generate_Range_Check
(Expr, Target_Type, CE_Range_Check_Failed);
end if;
end if;
end;
end if;
-- Final step, if the result is a type conversion involving Vax_Float
-- types, then it is subject for further special processing.
if Nkind (N) = N_Type_Conversion
and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type))
then
Expand_Vax_Conversion (N);
goto Done;
end if;
-- Here at end of processing
<<Done>>
-- Apply predicate check if required. Note that we can't just call
-- Apply_Predicate_Check here, because the type looks right after
-- the conversion and it would omit the check. The Comes_From_Source
-- guard is necessary to prevent infinite recursions when we generate
-- internal conversions for the purpose of checking predicates.
if Present (Predicate_Function (Target_Type))
and then Target_Type /= Operand_Type
and then Comes_From_Source (N)
then
declare
New_Expr : constant Node_Id := Duplicate_Subexpr (N);
begin
-- Avoid infinite recursion on the subsequent expansion of
-- of the copy of the original type conversion.
Set_Comes_From_Source (New_Expr, False);
Insert_Action (N, Make_Predicate_Check (Target_Type, New_Expr));
end;
end if;
end Expand_N_Type_Conversion;
-----------------------------------
-- Expand_N_Unchecked_Expression --
-----------------------------------
-- Remove the unchecked expression node from the tree. Its job was simply
-- to make sure that its constituent expression was handled with checks
-- off, and now that that is done, we can remove it from the tree, and
-- indeed must, since Gigi does not expect to see these nodes.
procedure Expand_N_Unchecked_Expression (N : Node_Id) is
Exp : constant Node_Id := Expression (N);
begin
Set_Assignment_OK (Exp, Assignment_OK (N) or else Assignment_OK (Exp));
Rewrite (N, Exp);
end Expand_N_Unchecked_Expression;
----------------------------------------
-- Expand_N_Unchecked_Type_Conversion --
----------------------------------------
-- If this cannot be handled by Gigi and we haven't already made a
-- temporary for it, do it now.
procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is
Target_Type : constant Entity_Id := Etype (N);
Operand : constant Node_Id := Expression (N);
Operand_Type : constant Entity_Id := Etype (Operand);
begin
-- Nothing at all to do if conversion is to the identical type so remove
-- the conversion completely, it is useless, except that it may carry
-- an Assignment_OK indication which must be propagated to the operand.
if Operand_Type = Target_Type then
-- Code duplicates Expand_N_Unchecked_Expression above, factor???
if Assignment_OK (N) then
Set_Assignment_OK (Operand);
end if;
Rewrite (N, Relocate_Node (Operand));
return;
end if;
-- If we have a conversion of a compile time known value to a target
-- type and the value is in range of the target type, then we can simply
-- replace the construct by an integer literal of the correct type. We
-- only apply this to integer types being converted. Possibly it may
-- apply in other cases, but it is too much trouble to worry about.
-- Note that we do not do this transformation if the Kill_Range_Check
-- flag is set, since then the value may be outside the expected range.
-- This happens in the Normalize_Scalars case.
-- We also skip this if either the target or operand type is biased
-- because in this case, the unchecked conversion is supposed to
-- preserve the bit pattern, not the integer value.
if Is_Integer_Type (Target_Type)
and then not Has_Biased_Representation (Target_Type)
and then Is_Integer_Type (Operand_Type)
and then not Has_Biased_Representation (Operand_Type)
and then Compile_Time_Known_Value (Operand)
and then not Kill_Range_Check (N)
then
declare
Val : constant Uint := Expr_Value (Operand);
begin
if Compile_Time_Known_Value (Type_Low_Bound (Target_Type))
and then
Compile_Time_Known_Value (Type_High_Bound (Target_Type))
and then
Val >= Expr_Value (Type_Low_Bound (Target_Type))
and then
Val <= Expr_Value (Type_High_Bound (Target_Type))
then
Rewrite (N, Make_Integer_Literal (Sloc (N), Val));
-- If Address is the target type, just set the type to avoid a
-- spurious type error on the literal when Address is a visible
-- integer type.
if Is_Descendent_Of_Address (Target_Type) then
Set_Etype (N, Target_Type);
else
Analyze_And_Resolve (N, Target_Type);
end if;
return;
end if;
end;
end if;
-- Nothing to do if conversion is safe
if Safe_Unchecked_Type_Conversion (N) then
return;
end if;
-- Otherwise force evaluation unless Assignment_OK flag is set (this
-- flag indicates ??? More comments needed here)
if Assignment_OK (N) then
null;
else
Force_Evaluation (N);
end if;
end Expand_N_Unchecked_Type_Conversion;
----------------------------
-- Expand_Record_Equality --
----------------------------
-- For non-variant records, Equality is expanded when needed into:
-- and then Lhs.Discr1 = Rhs.Discr1
-- and then ...
-- and then Lhs.Discrn = Rhs.Discrn
-- and then Lhs.Cmp1 = Rhs.Cmp1
-- and then ...
-- and then Lhs.Cmpn = Rhs.Cmpn
-- The expression is folded by the back-end for adjacent fields. This
-- function is called for tagged record in only one occasion: for imple-
-- menting predefined primitive equality (see Predefined_Primitives_Bodies)
-- otherwise the primitive "=" is used directly.
function Expand_Record_Equality
(Nod : Node_Id;
Typ : Entity_Id;
Lhs : Node_Id;
Rhs : Node_Id;
Bodies : List_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Nod);
Result : Node_Id;
C : Entity_Id;
First_Time : Boolean := True;
function Suitable_Element (C : Entity_Id) return Entity_Id;
-- Return the first field to compare beginning with C, skipping the
-- inherited components.
----------------------
-- Suitable_Element --
----------------------
function Suitable_Element (C : Entity_Id) return Entity_Id is
begin
if No (C) then
return Empty;
elsif Ekind (C) /= E_Discriminant
and then Ekind (C) /= E_Component
then
return Suitable_Element (Next_Entity (C));
-- Below test for C /= Original_Record_Component (C) is dubious
-- if Typ is a constrained record subtype???
elsif Is_Tagged_Type (Typ)
and then C /= Original_Record_Component (C)
then
return Suitable_Element (Next_Entity (C));
elsif Chars (C) = Name_uTag then
return Suitable_Element (Next_Entity (C));
-- The .NET/JVM version of type Root_Controlled contains two fields
-- which should not be considered part of the object. To achieve
-- proper equiality between two controlled objects on .NET/JVM, skip
-- field _parent whenever it is of type Root_Controlled.
elsif Chars (C) = Name_uParent
and then VM_Target /= No_VM
and then Etype (C) = RTE (RE_Root_Controlled)
then
return Suitable_Element (Next_Entity (C));
elsif Is_Interface (Etype (C)) then
return Suitable_Element (Next_Entity (C));
else
return C;
end if;
end Suitable_Element;
-- Start of processing for Expand_Record_Equality
begin
-- Generates the following code: (assuming that Typ has one Discr and
-- component C2 is also a record)
-- True
-- and then Lhs.Discr1 = Rhs.Discr1
-- and then Lhs.C1 = Rhs.C1
-- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
-- and then ...
-- and then Lhs.Cmpn = Rhs.Cmpn
Result := New_Reference_To (Standard_True, Loc);
C := Suitable_Element (First_Entity (Typ));
while Present (C) loop
declare
New_Lhs : Node_Id;
New_Rhs : Node_Id;
Check : Node_Id;
begin
if First_Time then
First_Time := False;
New_Lhs := Lhs;
New_Rhs := Rhs;
else
New_Lhs := New_Copy_Tree (Lhs);
New_Rhs := New_Copy_Tree (Rhs);
end if;
Check :=
Expand_Composite_Equality (Nod, Etype (C),
Lhs =>
Make_Selected_Component (Loc,
Prefix => New_Lhs,
Selector_Name => New_Reference_To (C, Loc)),
Rhs =>
Make_Selected_Component (Loc,
Prefix => New_Rhs,
Selector_Name => New_Reference_To (C, Loc)),
Bodies => Bodies);
-- If some (sub)component is an unchecked_union, the whole
-- operation will raise program error.
if Nkind (Check) = N_Raise_Program_Error then
Result := Check;
Set_Etype (Result, Standard_Boolean);
exit;
else
Result :=
Make_And_Then (Loc,
Left_Opnd => Result,
Right_Opnd => Check);
end if;
end;
C := Suitable_Element (Next_Entity (C));
end loop;
return Result;
end Expand_Record_Equality;
---------------------------
-- Expand_Set_Membership --
---------------------------
procedure Expand_Set_Membership (N : Node_Id) is
Lop : constant Node_Id := Left_Opnd (N);
Alt : Node_Id;
Res : Node_Id;
function Make_Cond (Alt : Node_Id) return Node_Id;
-- If the alternative is a subtype mark, create a simple membership
-- test. Otherwise create an equality test for it.
---------------
-- Make_Cond --
---------------
function Make_Cond (Alt : Node_Id) return Node_Id is
Cond : Node_Id;
L : constant Node_Id := New_Copy (Lop);
R : constant Node_Id := Relocate_Node (Alt);
begin
if (Is_Entity_Name (Alt) and then Is_Type (Entity (Alt)))
or else Nkind (Alt) = N_Range
then
Cond :=
Make_In (Sloc (Alt),
Left_Opnd => L,
Right_Opnd => R);
else
Cond :=
Make_Op_Eq (Sloc (Alt),
Left_Opnd => L,
Right_Opnd => R);
end if;
return Cond;
end Make_Cond;
-- Start of processing for Expand_Set_Membership
begin
Remove_Side_Effects (Lop);
Alt := Last (Alternatives (N));
Res := Make_Cond (Alt);
Prev (Alt);
while Present (Alt) loop
Res :=
Make_Or_Else (Sloc (Alt),
Left_Opnd => Make_Cond (Alt),
Right_Opnd => Res);
Prev (Alt);
end loop;
Rewrite (N, Res);
Analyze_And_Resolve (N, Standard_Boolean);
end Expand_Set_Membership;
-----------------------------------
-- Expand_Short_Circuit_Operator --
-----------------------------------
-- Deal with special expansion if actions are present for the right operand
-- and deal with optimizing case of arguments being True or False. We also
-- deal with the special case of non-standard boolean values.
procedure Expand_Short_Circuit_Operator (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Left : constant Node_Id := Left_Opnd (N);
Right : constant Node_Id := Right_Opnd (N);
LocR : constant Source_Ptr := Sloc (Right);
Actlist : List_Id;
Shortcut_Value : constant Boolean := Nkind (N) = N_Or_Else;
Shortcut_Ent : constant Entity_Id := Boolean_Literals (Shortcut_Value);
-- If Left = Shortcut_Value then Right need not be evaluated
function Make_Test_Expr (Opnd : Node_Id) return Node_Id;
-- For Opnd a boolean expression, return a Boolean expression equivalent
-- to Opnd /= Shortcut_Value.
--------------------
-- Make_Test_Expr --
--------------------
function Make_Test_Expr (Opnd : Node_Id) return Node_Id is
begin
if Shortcut_Value then
return Make_Op_Not (Sloc (Opnd), Opnd);
else
return Opnd;
end if;
end Make_Test_Expr;
Op_Var : Entity_Id;
-- Entity for a temporary variable holding the value of the operator,
-- used for expansion in the case where actions are present.
-- Start of processing for Expand_Short_Circuit_Operator
begin
-- Deal with non-standard booleans
if Is_Boolean_Type (Typ) then
Adjust_Condition (Left);
Adjust_Condition (Right);
Set_Etype (N, Standard_Boolean);
end if;
-- Check for cases where left argument is known to be True or False
if Compile_Time_Known_Value (Left) then
-- Mark SCO for left condition as compile time known
if Generate_SCO and then Comes_From_Source (Left) then
Set_SCO_Condition (Left, Expr_Value_E (Left) = Standard_True);
end if;
-- Rewrite True AND THEN Right / False OR ELSE Right to Right.
-- Any actions associated with Right will be executed unconditionally
-- and can thus be inserted into the tree unconditionally.
if Expr_Value_E (Left) /= Shortcut_Ent then
if Present (Actions (N)) then
Insert_Actions (N, Actions (N));
end if;
Rewrite (N, Right);
-- Rewrite False AND THEN Right / True OR ELSE Right to Left.
-- In this case we can forget the actions associated with Right,
-- since they will never be executed.
else
Kill_Dead_Code (Right);
Kill_Dead_Code (Actions (N));
Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
end if;
Adjust_Result_Type (N, Typ);
return;
end if;
-- If Actions are present for the right operand, we have to do some
-- special processing. We can't just let these actions filter back into
-- code preceding the short circuit (which is what would have happened
-- if we had not trapped them in the short-circuit form), since they
-- must only be executed if the right operand of the short circuit is
-- executed and not otherwise.
-- the temporary variable C.
if Present (Actions (N)) then
Actlist := Actions (N);
-- The old approach is to expand:
-- left AND THEN right
-- into
-- C : Boolean := False;
-- IF left THEN
-- Actions;
-- IF right THEN
-- C := True;
-- END IF;
-- END IF;
-- and finally rewrite the operator into a reference to C. Similarly
-- for left OR ELSE right, with negated values. Note that this
-- rewrite causes some difficulties for coverage analysis because
-- of the introduction of the new variable C, which obscures the
-- structure of the test.
-- We use this "old approach" if use of N_Expression_With_Actions
-- is False (see description in Opt of when this is or is not set).
if not Use_Expression_With_Actions then
Op_Var := Make_Temporary (Loc, 'C', Related_Node => N);
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier =>
Op_Var,
Object_Definition =>
New_Occurrence_Of (Standard_Boolean, Loc),
Expression =>
New_Occurrence_Of (Shortcut_Ent, Loc)));
Append_To (Actlist,
Make_Implicit_If_Statement (Right,
Condition => Make_Test_Expr (Right),
Then_Statements => New_List (
Make_Assignment_Statement (LocR,
Name => New_Occurrence_Of (Op_Var, LocR),
Expression =>
New_Occurrence_Of
(Boolean_Literals (not Shortcut_Value), LocR)))));
Insert_Action (N,
Make_Implicit_If_Statement (Left,
Condition => Make_Test_Expr (Left),
Then_Statements => Actlist));
Rewrite (N, New_Occurrence_Of (Op_Var, Loc));
Analyze_And_Resolve (N, Standard_Boolean);
-- The new approach, activated for now by the use of debug flag
-- -gnatd.X is to use the new Expression_With_Actions node for the
-- right operand of the short-circuit form. This should solve the
-- traceability problems for coverage analysis.
else
Rewrite (Right,
Make_Expression_With_Actions (LocR,
Expression => Relocate_Node (Right),
Actions => Actlist));
Set_Actions (N, No_List);
Analyze_And_Resolve (Right, Standard_Boolean);
end if;
Adjust_Result_Type (N, Typ);
return;
end if;
-- No actions present, check for cases of right argument True/False
if Compile_Time_Known_Value (Right) then
-- Mark SCO for left condition as compile time known
if Generate_SCO and then Comes_From_Source (Right) then
Set_SCO_Condition (Right, Expr_Value_E (Right) = Standard_True);
end if;
-- Change (Left and then True), (Left or else False) to Left.
-- Note that we know there are no actions associated with the right
-- operand, since we just checked for this case above.
if Expr_Value_E (Right) /= Shortcut_Ent then
Rewrite (N, Left);
-- Change (Left and then False), (Left or else True) to Right,
-- making sure to preserve any side effects associated with the Left
-- operand.
else
Remove_Side_Effects (Left);
Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
end if;
end if;
Adjust_Result_Type (N, Typ);
end Expand_Short_Circuit_Operator;
-------------------------------------
-- Fixup_Universal_Fixed_Operation --
-------------------------------------
procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is
Conv : constant Node_Id := Parent (N);
begin
-- We must have a type conversion immediately above us
pragma Assert (Nkind (Conv) = N_Type_Conversion);
-- Normally the type conversion gives our target type. The exception
-- occurs in the case of the Round attribute, where the conversion
-- will be to universal real, and our real type comes from the Round
-- attribute (as well as an indication that we must round the result)
if Nkind (Parent (Conv)) = N_Attribute_Reference
and then Attribute_Name (Parent (Conv)) = Name_Round
then
Set_Etype (N, Etype (Parent (Conv)));
Set_Rounded_Result (N);
-- Normal case where type comes from conversion above us
else
Set_Etype (N, Etype (Conv));
end if;
end Fixup_Universal_Fixed_Operation;
---------------------------------
-- Has_Inferable_Discriminants --
---------------------------------
function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
-- Determines whether the left-most prefix of a selected component is a
-- formal parameter in a subprogram. Assumes N is a selected component.
--------------------------------
-- Prefix_Is_Formal_Parameter --
--------------------------------
function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
Sel_Comp : Node_Id;
begin
-- Move to the left-most prefix by climbing up the tree
Sel_Comp := N;
while Present (Parent (Sel_Comp))
and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
loop
Sel_Comp := Parent (Sel_Comp);
end loop;
return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
end Prefix_Is_Formal_Parameter;
-- Start of processing for Has_Inferable_Discriminants
begin
-- For selected components, the subtype of the selector must be a
-- constrained Unchecked_Union. If the component is subject to a
-- per-object constraint, then the enclosing object must have inferable
-- discriminants.
if Nkind (N) = N_Selected_Component then
if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
-- A small hack. If we have a per-object constrained selected
-- component of a formal parameter, return True since we do not
-- know the actual parameter association yet.
if Prefix_Is_Formal_Parameter (N) then
return True;
-- Otherwise, check the enclosing object and the selector
else
return Has_Inferable_Discriminants (Prefix (N))
and then Has_Inferable_Discriminants (Selector_Name (N));
end if;
-- The call to Has_Inferable_Discriminants will determine whether
-- the selector has a constrained Unchecked_Union nominal type.
else
return Has_Inferable_Discriminants (Selector_Name (N));
end if;
-- A qualified expression has inferable discriminants if its subtype
-- mark is a constrained Unchecked_Union subtype.
elsif Nkind (N) = N_Qualified_Expression then
return Is_Unchecked_Union (Etype (Subtype_Mark (N)))
and then Is_Constrained (Etype (Subtype_Mark (N)));
-- For all other names, it is sufficient to have a constrained
-- Unchecked_Union nominal subtype.
else
return Is_Unchecked_Union (Base_Type (Etype (N)))
and then Is_Constrained (Etype (N));
end if;
end Has_Inferable_Discriminants;
-------------------------------
-- Insert_Dereference_Action --
-------------------------------
procedure Insert_Dereference_Action (N : Node_Id) is
function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean;
-- Return true if type of P is derived from Checked_Pool;
-----------------------------
-- Is_Checked_Storage_Pool --
-----------------------------
function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is
T : Entity_Id;
begin
if No (P) then
return False;
end if;
T := Etype (P);
while T /= Etype (T) loop
if Is_RTE (T, RE_Checked_Pool) then
return True;
else
T := Etype (T);
end if;
end loop;
return False;
end Is_Checked_Storage_Pool;
-- Local variables
Typ : constant Entity_Id := Etype (N);
Desig : constant Entity_Id := Available_View (Designated_Type (Typ));
Loc : constant Source_Ptr := Sloc (N);
Pool : constant Entity_Id := Associated_Storage_Pool (Typ);
Pnod : constant Node_Id := Parent (N);
Addr : Entity_Id;
Alig : Entity_Id;
Deref : Node_Id;
Size : Entity_Id;
Stmt : Node_Id;
-- Start of processing for Insert_Dereference_Action
begin
pragma Assert (Nkind (Pnod) = N_Explicit_Dereference);
-- Do not re-expand a dereference which has already been processed by
-- this routine.
if Has_Dereference_Action (Pnod) then
return;
-- Do not perform this type of expansion for internally-generated
-- dereferences.
elsif not Comes_From_Source (Original_Node (Pnod)) then
return;
-- A dereference action is only applicable to objects which have been
-- allocated on a checked pool.
elsif not Is_Checked_Storage_Pool (Pool) then
return;
end if;
-- Extract the address of the dereferenced object. Generate:
-- Addr : System.Address := <N>'Pool_Address;
Addr := Make_Temporary (Loc, 'P');
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Addr,
Object_Definition =>
New_Reference_To (RTE (RE_Address), Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr_Move_Checks (N),
Attribute_Name => Name_Pool_Address)));
-- Calculate the size of the dereferenced object. Generate:
-- Size : Storage_Count := <N>.all'Size / Storage_Unit;
Deref :=
Make_Explicit_Dereference (Loc,
Prefix => Duplicate_Subexpr_Move_Checks (N));
Set_Has_Dereference_Action (Deref);
Size := Make_Temporary (Loc, 'S');
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Size,
Object_Definition =>
New_Reference_To (RTE (RE_Storage_Count), Loc),
Expression =>
Make_Op_Divide (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => Deref,
Attribute_Name => Name_Size),
Right_Opnd =>
Make_Integer_Literal (Loc, System_Storage_Unit))));
-- Calculate the alignment of the dereferenced object. Generate:
-- Alig : constant Storage_Count := <N>.all'Alignment;
Deref :=
Make_Explicit_Dereference (Loc,
Prefix => Duplicate_Subexpr_Move_Checks (N));
Set_Has_Dereference_Action (Deref);
Alig := Make_Temporary (Loc, 'A');
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Alig,
Object_Definition =>
New_Reference_To (RTE (RE_Storage_Count), Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => Deref,
Attribute_Name => Name_Alignment)));
-- A dereference of a controlled object requires special processing. The
-- finalization machinery requests additional space from the underlying
-- pool to allocate and hide two pointers. As a result, a checked pool
-- may mark the wrong memory as valid. Since checked pools do not have
-- knowledge of hidden pointers, we have to bring the two pointers back
-- in view in order to restore the original state of the object.
if Needs_Finalization (Desig) then
-- Adjust the address and size of the dereferenced object. Generate:
-- Adjust_Controlled_Dereference (Addr, Size, Alig);
Stmt :=
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (RTE (RE_Adjust_Controlled_Dereference), Loc),
Parameter_Associations => New_List (
New_Reference_To (Addr, Loc),
New_Reference_To (Size, Loc),
New_Reference_To (Alig, Loc)));
-- Class-wide types complicate things because we cannot determine
-- statically whether the actual object is truly controlled. We must
-- generate a runtime check to detect this property. Generate:
--
-- if Needs_Finalization (<N>.all'Tag) then
-- <Stmt>;
-- end if;
if Is_Class_Wide_Type (Desig) then
Deref :=
Make_Explicit_Dereference (Loc,
Prefix => Duplicate_Subexpr_Move_Checks (N));
Set_Has_Dereference_Action (Deref);
Stmt :=
Make_If_Statement (Loc,
Condition =>
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Needs_Finalization), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => Deref,
Attribute_Name => Name_Tag))),
Then_Statements => New_List (Stmt));
end if;
Insert_Action (N, Stmt);
end if;
-- Generate:
-- Dereference (Pool, Addr, Size, Alig);
Insert_Action (N,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To
(Find_Prim_Op (Etype (Pool), Name_Dereference), Loc),
Parameter_Associations => New_List (
New_Reference_To (Pool, Loc),
New_Reference_To (Addr, Loc),
New_Reference_To (Size, Loc),
New_Reference_To (Alig, Loc))));
-- Mark the explicit dereference as processed to avoid potential
-- infinite expansion.
Set_Has_Dereference_Action (Pnod);
exception
when RE_Not_Available =>
return;
end Insert_Dereference_Action;
--------------------------------
-- Integer_Promotion_Possible --
--------------------------------
function Integer_Promotion_Possible (N : Node_Id) return Boolean is
Operand : constant Node_Id := Expression (N);
Operand_Type : constant Entity_Id := Etype (Operand);
Root_Operand_Type : constant Entity_Id := Root_Type (Operand_Type);
begin
pragma Assert (Nkind (N) = N_Type_Conversion);
return
-- We only do the transformation for source constructs. We assume
-- that the expander knows what it is doing when it generates code.
Comes_From_Source (N)
-- If the operand type is Short_Integer or Short_Short_Integer,
-- then we will promote to Integer, which is available on all
-- targets, and is sufficient to ensure no intermediate overflow.
-- Furthermore it is likely to be as efficient or more efficient
-- than using the smaller type for the computation so we do this
-- unconditionally.
and then
(Root_Operand_Type = Base_Type (Standard_Short_Integer)
or else
Root_Operand_Type = Base_Type (Standard_Short_Short_Integer))
-- Test for interesting operation, which includes addition,
-- division, exponentiation, multiplication, subtraction, absolute
-- value and unary negation. Unary "+" is omitted since it is a
-- no-op and thus can't overflow.
and then Nkind_In (Operand, N_Op_Abs,
N_Op_Add,
N_Op_Divide,
N_Op_Expon,
N_Op_Minus,
N_Op_Multiply,
N_Op_Subtract);
end Integer_Promotion_Possible;
------------------------------
-- Make_Array_Comparison_Op --
------------------------------
-- This is a hand-coded expansion of the following generic function:
-- generic
-- type elem is (<>);
-- type index is (<>);
-- type a is array (index range <>) of elem;
-- function Gnnn (X : a; Y: a) return boolean is
-- J : index := Y'first;
-- begin
-- if X'length = 0 then
-- return false;
-- elsif Y'length = 0 then
-- return true;
-- else
-- for I in X'range loop
-- if X (I) = Y (J) then
-- if J = Y'last then
-- exit;
-- else
-- J := index'succ (J);
-- end if;
-- else
-- return X (I) > Y (J);
-- end if;
-- end loop;
-- return X'length > Y'length;
-- end if;
-- end Gnnn;
-- Note that since we are essentially doing this expansion by hand, we
-- do not need to generate an actual or formal generic part, just the
-- instantiated function itself.
function Make_Array_Comparison_Op
(Typ : Entity_Id;
Nod : Node_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (Nod);
X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX);
Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY);
I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI);
J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ)));
Loop_Statement : Node_Id;
Loop_Body : Node_Id;
If_Stat : Node_Id;
Inner_If : Node_Id;
Final_Expr : Node_Id;
Func_Body : Node_Id;
Func_Name : Entity_Id;
Formals : List_Id;
Length1 : Node_Id;
Length2 : Node_Id;
begin
-- if J = Y'last then
-- exit;
-- else
-- J := index'succ (J);
-- end if;
Inner_If :=
Make_Implicit_If_Statement (Nod,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd => New_Reference_To (J, Loc),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Y, Loc),
Attribute_Name => Name_Last)),
Then_Statements => New_List (
Make_Exit_Statement (Loc)),
Else_Statements =>
New_List (
Make_Assignment_Statement (Loc,
Name => New_Reference_To (J, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Index, Loc),
Attribute_Name => Name_Succ,
Expressions => New_List (New_Reference_To (J, Loc))))));
-- if X (I) = Y (J) then
-- if ... end if;
-- else
-- return X (I) > Y (J);
-- end if;
Loop_Body :=
Make_Implicit_If_Statement (Nod,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (X, Loc),
Expressions => New_List (New_Reference_To (I, Loc))),
Right_Opnd =>
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Y, Loc),
Expressions => New_List (New_Reference_To (J, Loc)))),
Then_Statements => New_List (Inner_If),
Else_Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression =>
Make_Op_Gt (Loc,
Left_Opnd =>
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (X, Loc),
Expressions => New_List (New_Reference_To (I, Loc))),
Right_Opnd =>
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Y, Loc),
Expressions => New_List (
New_Reference_To (J, Loc)))))));
-- for I in X'range loop
-- if ... end if;
-- end loop;
Loop_Statement :=
Make_Implicit_Loop_Statement (Nod,
Identifier => Empty,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => I,
Discrete_Subtype_Definition =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (X, Loc),
Attribute_Name => Name_Range))),
Statements => New_List (Loop_Body));
-- if X'length = 0 then
-- return false;
-- elsif Y'length = 0 then
-- return true;
-- else
-- for ... loop ... end loop;
-- return X'length > Y'length;
-- end if;
Length1 :=
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (X, Loc),
Attribute_Name => Name_Length);
Length2 :=
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Y, Loc),
Attribute_Name => Name_Length);
Final_Expr :=
Make_Op_Gt (Loc,
Left_Opnd => Length1,
Right_Opnd => Length2);
If_Stat :=
Make_Implicit_If_Statement (Nod,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (X, Loc),
Attribute_Name => Name_Length),
Right_Opnd =>
Make_Integer_Literal (Loc, 0)),
Then_Statements =>
New_List (
Make_Simple_Return_Statement (Loc,
Expression => New_Reference_To (Standard_False, Loc))),
Elsif_Parts => New_List (
Make_Elsif_Part (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Y, Loc),
Attribute_Name => Name_Length),
Right_Opnd =>
Make_Integer_Literal (Loc, 0)),
Then_Statements =>
New_List (
Make_Simple_Return_Statement (Loc,
Expression => New_Reference_To (Standard_True, Loc))))),
Else_Statements => New_List (
Loop_Statement,
Make_Simple_Return_Statement (Loc,
Expression => Final_Expr)));
-- (X : a; Y: a)
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => X,
Parameter_Type => New_Reference_To (Typ, Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => Y,
Parameter_Type => New_Reference_To (Typ, Loc)));
-- function Gnnn (...) return boolean is
-- J : index := Y'first;
-- begin
-- if ... end if;
-- end Gnnn;
Func_Name := Make_Temporary (Loc, 'G');
Func_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Func_Name,
Parameter_Specifications => Formals,
Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
Declarations => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => J,
Object_Definition => New_Reference_To (Index, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Y, Loc),
Attribute_Name => Name_First))),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (If_Stat)));
return Func_Body;
end Make_Array_Comparison_Op;
---------------------------
-- Make_Boolean_Array_Op --
---------------------------
-- For logical operations on boolean arrays, expand in line the following,
-- replacing 'and' with 'or' or 'xor' where needed:
-- function Annn (A : typ; B: typ) return typ is
-- C : typ;
-- begin
-- for J in A'range loop
-- C (J) := A (J) op B (J);
-- end loop;
-- return C;
-- end Annn;
-- Here typ is the boolean array type
function Make_Boolean_Array_Op
(Typ : Entity_Id;
N : Node_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC);
J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
A_J : Node_Id;
B_J : Node_Id;
C_J : Node_Id;
Op : Node_Id;
Formals : List_Id;
Func_Name : Entity_Id;
Func_Body : Node_Id;
Loop_Statement : Node_Id;
begin
A_J :=
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (A, Loc),
Expressions => New_List (New_Reference_To (J, Loc)));
B_J :=
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (B, Loc),
Expressions => New_List (New_Reference_To (J, Loc)));
C_J :=
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (C, Loc),
Expressions => New_List (New_Reference_To (J, Loc)));
if Nkind (N) = N_Op_And then
Op :=
Make_Op_And (Loc,
Left_Opnd => A_J,
Right_Opnd => B_J);
elsif Nkind (N) = N_Op_Or then
Op :=
Make_Op_Or (Loc,
Left_Opnd => A_J,
Right_Opnd => B_J);
else
Op :=
Make_Op_Xor (Loc,
Left_Opnd => A_J,
Right_Opnd => B_J);
end if;
Loop_Statement :=
Make_Implicit_Loop_Statement (N,
Identifier => Empty,
Iteration_Scheme =>
Make_Iteration_Scheme (Loc,
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => J,
Discrete_Subtype_Definition =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (A, Loc),
Attribute_Name => Name_Range))),
Statements => New_List (
Make_Assignment_Statement (Loc,
Name => C_J,
Expression => Op)));
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => A,
Parameter_Type => New_Reference_To (Typ, Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => B,
Parameter_Type => New_Reference_To (Typ, Loc)));
Func_Name := Make_Temporary (Loc, 'A');
Set_Is_Inlined (Func_Name);
Func_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Func_Name,
Parameter_Specifications => Formals,
Result_Definition => New_Reference_To (Typ, Loc)),
Declarations => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => C,
Object_Definition => New_Reference_To (Typ, Loc))),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Loop_Statement,
Make_Simple_Return_Statement (Loc,
Expression => New_Reference_To (C, Loc)))));
return Func_Body;
end Make_Boolean_Array_Op;
-----------------------------------------
-- Minimized_Eliminated_Overflow_Check --
-----------------------------------------
function Minimized_Eliminated_Overflow_Check (N : Node_Id) return Boolean is
begin
return
Is_Signed_Integer_Type (Etype (N))
and then Overflow_Check_Mode in Minimized_Or_Eliminated;
end Minimized_Eliminated_Overflow_Check;
--------------------------------
-- Optimize_Length_Comparison --
--------------------------------
procedure Optimize_Length_Comparison (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Result : Node_Id;
Left : Node_Id;
Right : Node_Id;
-- First and Last attribute reference nodes, which end up as left and
-- right operands of the optimized result.
Is_Zero : Boolean;
-- True for comparison operand of zero
Comp : Node_Id;
-- Comparison operand, set only if Is_Zero is false
Ent : Entity_Id;
-- Entity whose length is being compared
Index : Node_Id;
-- Integer_Literal node for length attribute expression, or Empty
-- if there is no such expression present.
Ityp : Entity_Id;
-- Type of array index to which 'Length is applied
Op : Node_Kind := Nkind (N);
-- Kind of comparison operator, gets flipped if operands backwards
function Is_Optimizable (N : Node_Id) return Boolean;
-- Tests N to see if it is an optimizable comparison value (defined as
-- constant zero or one, or something else where the value is known to
-- be positive and in the range of 32-bits, and where the corresponding
-- Length value is also known to be 32-bits. If result is true, sets
-- Is_Zero, Ityp, and Comp accordingly.
function Is_Entity_Length (N : Node_Id) return Boolean;
-- Tests if N is a length attribute applied to a simple entity. If so,
-- returns True, and sets Ent to the entity, and Index to the integer
-- literal provided as an attribute expression, or to Empty if none.
-- Also returns True if the expression is a generated type conversion
-- whose expression is of the desired form. This latter case arises
-- when Apply_Universal_Integer_Attribute_Check installs a conversion
-- to check for being in range, which is not needed in this context.
-- Returns False if neither condition holds.
function Prepare_64 (N : Node_Id) return Node_Id;
-- Given a discrete expression, returns a Long_Long_Integer typed
-- expression representing the underlying value of the expression.
-- This is done with an unchecked conversion to the result type. We
-- use unchecked conversion to handle the enumeration type case.
----------------------
-- Is_Entity_Length --
----------------------
function Is_Entity_Length (N : Node_Id) return Boolean is
begin
if Nkind (N) = N_Attribute_Reference
and then Attribute_Name (N) = Name_Length
and then Is_Entity_Name (Prefix (N))
then
Ent := Entity (Prefix (N));
if Present (Expressions (N)) then
Index := First (Expressions (N));
else
Index := Empty;
end if;
return True;
elsif Nkind (N) = N_Type_Conversion
and then not Comes_From_Source (N)
then
return Is_Entity_Length (Expression (N));
else
return False;
end if;
end Is_Entity_Length;
--------------------
-- Is_Optimizable --
--------------------
function Is_Optimizable (N : Node_Id) return Boolean is
Val : Uint;
OK : Boolean;
Lo : Uint;
Hi : Uint;
Indx : Node_Id;
begin
if Compile_Time_Known_Value (N) then
Val := Expr_Value (N);
if Val = Uint_0 then
Is_Zero := True;
Comp := Empty;
return True;
elsif Val = Uint_1 then
Is_Zero := False;
Comp := Empty;
return True;
end if;
end if;
-- Here we have to make sure of being within 32-bits
Determine_Range (N, OK, Lo, Hi, Assume_Valid => True);
if not OK
or else Lo < Uint_1
or else Hi > UI_From_Int (Int'Last)
then
return False;
end if;
-- Comparison value was within range, so now we must check the index
-- value to make sure it is also within 32-bits.
Indx := First_Index (Etype (Ent));
if Present (Index) then
for J in 2 .. UI_To_Int (Intval (Index)) loop
Next_Index (Indx);
end loop;
end if;
Ityp := Etype (Indx);
if Esize (Ityp) > 32 then
return False;
end if;
Is_Zero := False;
Comp := N;
return True;
end Is_Optimizable;
----------------
-- Prepare_64 --
----------------
function Prepare_64 (N : Node_Id) return Node_Id is
begin
return Unchecked_Convert_To (Standard_Long_Long_Integer, N);
end Prepare_64;
-- Start of processing for Optimize_Length_Comparison
begin
-- Nothing to do if not a comparison
if Op not in N_Op_Compare then
return;
end if;
-- Nothing to do if special -gnatd.P debug flag set
if Debug_Flag_Dot_PP then
return;
end if;
-- Ent'Length op 0/1
if Is_Entity_Length (Left_Opnd (N))
and then Is_Optimizable (Right_Opnd (N))
then
null;
-- 0/1 op Ent'Length
elsif Is_Entity_Length (Right_Opnd (N))
and then Is_Optimizable (Left_Opnd (N))
then
-- Flip comparison to opposite sense
case Op is
when N_Op_Lt => Op := N_Op_Gt;
when N_Op_Le => Op := N_Op_Ge;
when N_Op_Gt => Op := N_Op_Lt;
when N_Op_Ge => Op := N_Op_Le;
when others => null;
end case;
-- Else optimization not possible
else
return;
end if;
-- Fall through if we will do the optimization
-- Cases to handle:
-- X'Length = 0 => X'First > X'Last
-- X'Length = 1 => X'First = X'Last
-- X'Length = n => X'First + (n - 1) = X'Last
-- X'Length /= 0 => X'First <= X'Last
-- X'Length /= 1 => X'First /= X'Last
-- X'Length /= n => X'First + (n - 1) /= X'Last
-- X'Length >= 0 => always true, warn
-- X'Length >= 1 => X'First <= X'Last
-- X'Length >= n => X'First + (n - 1) <= X'Last
-- X'Length > 0 => X'First <= X'Last
-- X'Length > 1 => X'First < X'Last
-- X'Length > n => X'First + (n - 1) < X'Last
-- X'Length <= 0 => X'First > X'Last (warn, could be =)
-- X'Length <= 1 => X'First >= X'Last
-- X'Length <= n => X'First + (n - 1) >= X'Last
-- X'Length < 0 => always false (warn)
-- X'Length < 1 => X'First > X'Last
-- X'Length < n => X'First + (n - 1) > X'Last
-- Note: for the cases of n (not constant 0,1), we require that the
-- corresponding index type be integer or shorter (i.e. not 64-bit),
-- and the same for the comparison value. Then we do the comparison
-- using 64-bit arithmetic (actually long long integer), so that we
-- cannot have overflow intefering with the result.
-- First deal with warning cases
if Is_Zero then
case Op is
-- X'Length >= 0
when N_Op_Ge =>
Rewrite (N,
Convert_To (Typ, New_Occurrence_Of (Standard_True, Loc)));
Analyze_And_Resolve (N, Typ);
Warn_On_Known_Condition (N);
return;
-- X'Length < 0
when N_Op_Lt =>
Rewrite (N,
Convert_To (Typ, New_Occurrence_Of (Standard_False, Loc)));
Analyze_And_Resolve (N, Typ);
Warn_On_Known_Condition (N);
return;
when N_Op_Le =>
if Constant_Condition_Warnings
and then Comes_From_Source (Original_Node (N))
then
Error_Msg_N ("could replace by ""'=""?c?", N);
end if;
Op := N_Op_Eq;
when others =>
null;
end case;
end if;
-- Build the First reference we will use
Left :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ent, Loc),
Attribute_Name => Name_First);
if Present (Index) then
Set_Expressions (Left, New_List (New_Copy (Index)));
end if;
-- If general value case, then do the addition of (n - 1), and
-- also add the needed conversions to type Long_Long_Integer.
if Present (Comp) then
Left :=
Make_Op_Add (Loc,
Left_Opnd => Prepare_64 (Left),
Right_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd => Prepare_64 (Comp),
Right_Opnd => Make_Integer_Literal (Loc, 1)));
end if;
-- Build the Last reference we will use
Right :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ent, Loc),
Attribute_Name => Name_Last);
if Present (Index) then
Set_Expressions (Right, New_List (New_Copy (Index)));
end if;
-- If general operand, convert Last reference to Long_Long_Integer
if Present (Comp) then
Right := Prepare_64 (Right);
end if;
-- Check for cases to optimize
-- X'Length = 0 => X'First > X'Last
-- X'Length < 1 => X'First > X'Last
-- X'Length < n => X'First + (n - 1) > X'Last
if (Is_Zero and then Op = N_Op_Eq)
or else (not Is_Zero and then Op = N_Op_Lt)
then
Result :=
Make_Op_Gt (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
-- X'Length = 1 => X'First = X'Last
-- X'Length = n => X'First + (n - 1) = X'Last
elsif not Is_Zero and then Op = N_Op_Eq then
Result :=
Make_Op_Eq (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
-- X'Length /= 0 => X'First <= X'Last
-- X'Length > 0 => X'First <= X'Last
elsif Is_Zero and (Op = N_Op_Ne or else Op = N_Op_Gt) then
Result :=
Make_Op_Le (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
-- X'Length /= 1 => X'First /= X'Last
-- X'Length /= n => X'First + (n - 1) /= X'Last
elsif not Is_Zero and then Op = N_Op_Ne then
Result :=
Make_Op_Ne (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
-- X'Length >= 1 => X'First <= X'Last
-- X'Length >= n => X'First + (n - 1) <= X'Last
elsif not Is_Zero and then Op = N_Op_Ge then
Result :=
Make_Op_Le (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
-- X'Length > 1 => X'First < X'Last
-- X'Length > n => X'First + (n = 1) < X'Last
elsif not Is_Zero and then Op = N_Op_Gt then
Result :=
Make_Op_Lt (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
-- X'Length <= 1 => X'First >= X'Last
-- X'Length <= n => X'First + (n - 1) >= X'Last
elsif not Is_Zero and then Op = N_Op_Le then
Result :=
Make_Op_Ge (Loc,
Left_Opnd => Left,
Right_Opnd => Right);
-- Should not happen at this stage
else
raise Program_Error;
end if;
-- Rewrite and finish up
Rewrite (N, Result);
Analyze_And_Resolve (N, Typ);
return;
end Optimize_Length_Comparison;
------------------------
-- Rewrite_Comparison --
------------------------
procedure Rewrite_Comparison (N : Node_Id) is
Warning_Generated : Boolean := False;
-- Set to True if first pass with Assume_Valid generates a warning in
-- which case we skip the second pass to avoid warning overloaded.
Result : Node_Id;
-- Set to Standard_True or Standard_False
begin
if Nkind (N) = N_Type_Conversion then
Rewrite_Comparison (Expression (N));
return;
elsif Nkind (N) not in N_Op_Compare then
return;
end if;
-- Now start looking at the comparison in detail. We potentially go
-- through this loop twice. The first time, Assume_Valid is set False
-- in the call to Compile_Time_Compare. If this call results in a
-- clear result of always True or Always False, that's decisive and
-- we are done. Otherwise we repeat the processing with Assume_Valid
-- set to True to generate additional warnings. We can skip that step
-- if Constant_Condition_Warnings is False.
for AV in False .. True loop
declare
Typ : constant Entity_Id := Etype (N);
Op1 : constant Node_Id := Left_Opnd (N);
Op2 : constant Node_Id := Right_Opnd (N);
Res : constant Compare_Result :=
Compile_Time_Compare (Op1, Op2, Assume_Valid => AV);
-- Res indicates if compare outcome can be compile time determined
True_Result : Boolean;
False_Result : Boolean;
begin
case N_Op_Compare (Nkind (N)) is
when N_Op_Eq =>
True_Result := Res = EQ;
False_Result := Res = LT or else Res = GT or else Res = NE;
when N_Op_Ge =>
True_Result := Res in Compare_GE;
False_Result := Res = LT;
if Res = LE
and then Constant_Condition_Warnings
and then Comes_From_Source (Original_Node (N))
and then Nkind (Original_Node (N)) = N_Op_Ge
and then not In_Instance
and then Is_Integer_Type (Etype (Left_Opnd (N)))
and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
then
Error_Msg_N
("can never be greater than, could replace by ""'=""?c?",
N);
Warning_Generated := True;
end if;
when N_Op_Gt =>
True_Result := Res = GT;
False_Result := Res in Compare_LE;
when N_Op_Lt =>
True_Result := Res = LT;
False_Result := Res in Compare_GE;
when N_Op_Le =>
True_Result := Res in Compare_LE;
False_Result := Res = GT;
if Res = GE
and then Constant_Condition_Warnings
and then Comes_From_Source (Original_Node (N))
and then Nkind (Original_Node (N)) = N_Op_Le
and then not In_Instance
and then Is_Integer_Type (Etype (Left_Opnd (N)))
and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
then
Error_Msg_N
("can never be less than, could replace by ""'=""?c?", N);
Warning_Generated := True;
end if;
when N_Op_Ne =>
True_Result := Res = NE or else Res = GT or else Res = LT;
False_Result := Res = EQ;
end case;
-- If this is the first iteration, then we actually convert the
-- comparison into True or False, if the result is certain.
if AV = False then
if True_Result or False_Result then
Result := Boolean_Literals (True_Result);
Rewrite (N,
Convert_To (Typ,
New_Occurrence_Of (Result, Sloc (N))));
Analyze_And_Resolve (N, Typ);
Warn_On_Known_Condition (N);
return;
end if;
-- If this is the second iteration (AV = True), and the original
-- node comes from source and we are not in an instance, then give
-- a warning if we know result would be True or False. Note: we
-- know Constant_Condition_Warnings is set if we get here.
elsif Comes_From_Source (Original_Node (N))
and then not In_Instance
then
if True_Result then
Error_Msg_N
("condition can only be False if invalid values present??",
N);
elsif False_Result then
Error_Msg_N
("condition can only be True if invalid values present??",
N);
end if;
end if;
end;
-- Skip second iteration if not warning on constant conditions or
-- if the first iteration already generated a warning of some kind or
-- if we are in any case assuming all values are valid (so that the
-- first iteration took care of the valid case).
exit when not Constant_Condition_Warnings;
exit when Warning_Generated;
exit when Assume_No_Invalid_Values;
end loop;
end Rewrite_Comparison;
----------------------------
-- Safe_In_Place_Array_Op --
----------------------------
function Safe_In_Place_Array_Op
(Lhs : Node_Id;
Op1 : Node_Id;
Op2 : Node_Id) return Boolean
is
Target : Entity_Id;
function Is_Safe_Operand (Op : Node_Id) return Boolean;
-- Operand is safe if it cannot overlap part of the target of the
-- operation. If the operand and the target are identical, the operand
-- is safe. The operand can be empty in the case of negation.
function Is_Unaliased (N : Node_Id) return Boolean;
-- Check that N is a stand-alone entity
------------------
-- Is_Unaliased --
------------------
function Is_Unaliased (N : Node_Id) return Boolean is
begin
return
Is_Entity_Name (N)
and then No (Address_Clause (Entity (N)))
and then No (Renamed_Object (Entity (N)));
end Is_Unaliased;
---------------------
-- Is_Safe_Operand --
---------------------
function Is_Safe_Operand (Op : Node_Id) return Boolean is
begin
if No (Op) then
return True;
elsif Is_Entity_Name (Op) then
return Is_Unaliased (Op);
elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then
return Is_Unaliased (Prefix (Op));
elsif Nkind (Op) = N_Slice then
return
Is_Unaliased (Prefix (Op))
and then Entity (Prefix (Op)) /= Target;
elsif Nkind (Op) = N_Op_Not then
return Is_Safe_Operand (Right_Opnd (Op));
else
return False;
end if;
end Is_Safe_Operand;
-- Start of processing for Safe_In_Place_Array_Op
begin
-- Skip this processing if the component size is different from system
-- storage unit (since at least for NOT this would cause problems).
if Component_Size (Etype (Lhs)) /= System_Storage_Unit then
return False;
-- Cannot do in place stuff on VM_Target since cannot pass addresses
elsif VM_Target /= No_VM then
return False;
-- Cannot do in place stuff if non-standard Boolean representation
elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then
return False;
elsif not Is_Unaliased (Lhs) then
return False;
else
Target := Entity (Lhs);
return Is_Safe_Operand (Op1) and then Is_Safe_Operand (Op2);
end if;
end Safe_In_Place_Array_Op;
-----------------------
-- Tagged_Membership --
-----------------------
-- There are two different cases to consider depending on whether the right
-- operand is a class-wide type or not. If not we just compare the actual
-- tag of the left expr to the target type tag:
--
-- Left_Expr.Tag = Right_Type'Tag;
--
-- If it is a class-wide type we use the RT function CW_Membership which is
-- usually implemented by looking in the ancestor tables contained in the
-- dispatch table pointed by Left_Expr.Tag for Typ'Tag
-- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
-- function IW_Membership which is usually implemented by looking in the
-- table of abstract interface types plus the ancestor table contained in
-- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
procedure Tagged_Membership
(N : Node_Id;
SCIL_Node : out Node_Id;
Result : out Node_Id)
is
Left : constant Node_Id := Left_Opnd (N);
Right : constant Node_Id := Right_Opnd (N);
Loc : constant Source_Ptr := Sloc (N);
Full_R_Typ : Entity_Id;
Left_Type : Entity_Id;
New_Node : Node_Id;
Right_Type : Entity_Id;
Obj_Tag : Node_Id;
begin
SCIL_Node := Empty;
-- Handle entities from the limited view
Left_Type := Available_View (Etype (Left));
Right_Type := Available_View (Etype (Right));
-- In the case where the type is an access type, the test is applied
-- using the designated types (needed in Ada 2012 for implicit anonymous
-- access conversions, for AI05-0149).
if Is_Access_Type (Right_Type) then
Left_Type := Designated_Type (Left_Type);
Right_Type := Designated_Type (Right_Type);
end if;
if Is_Class_Wide_Type (Left_Type) then
Left_Type := Root_Type (Left_Type);
end if;
if Is_Class_Wide_Type (Right_Type) then
Full_R_Typ := Underlying_Type (Root_Type (Right_Type));
else
Full_R_Typ := Underlying_Type (Right_Type);
end if;
Obj_Tag :=
Make_Selected_Component (Loc,
Prefix => Relocate_Node (Left),
Selector_Name =>
New_Reference_To (First_Tag_Component (Left_Type), Loc));
if Is_Class_Wide_Type (Right_Type) then
-- No need to issue a run-time check if we statically know that the
-- result of this membership test is always true. For example,
-- considering the following declarations:
-- type Iface is interface;
-- type T is tagged null record;
-- type DT is new T and Iface with null record;
-- Obj1 : T;
-- Obj2 : DT;
-- These membership tests are always true:
-- Obj1 in T'Class
-- Obj2 in T'Class;
-- Obj2 in Iface'Class;
-- We do not need to handle cases where the membership is illegal.
-- For example:
-- Obj1 in DT'Class; -- Compile time error
-- Obj1 in Iface'Class; -- Compile time error
if not Is_Class_Wide_Type (Left_Type)
and then (Is_Ancestor (Etype (Right_Type), Left_Type,
Use_Full_View => True)
or else (Is_Interface (Etype (Right_Type))
and then Interface_Present_In_Ancestor
(Typ => Left_Type,
Iface => Etype (Right_Type))))
then
Result := New_Reference_To (Standard_True, Loc);
return;
end if;
-- Ada 2005 (AI-251): Class-wide applied to interfaces
if Is_Interface (Etype (Class_Wide_Type (Right_Type)))
-- Support to: "Iface_CW_Typ in Typ'Class"
or else Is_Interface (Left_Type)
then
-- Issue error if IW_Membership operation not available in a
-- configurable run time setting.
if not RTE_Available (RE_IW_Membership) then
Error_Msg_CRT
("dynamic membership test on interface types", N);
Result := Empty;
return;
end if;
Result :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => Obj_Tag,
Attribute_Name => Name_Address),
New_Reference_To (
Node (First_Elmt (Access_Disp_Table (Full_R_Typ))),
Loc)));
-- Ada 95: Normal case
else
Build_CW_Membership (Loc,
Obj_Tag_Node => Obj_Tag,
Typ_Tag_Node =>
New_Reference_To (
Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc),
Related_Nod => N,
New_Node => New_Node);
-- Generate the SCIL node for this class-wide membership test.
-- Done here because the previous call to Build_CW_Membership
-- relocates Obj_Tag.
if Generate_SCIL then
SCIL_Node := Make_SCIL_Membership_Test (Sloc (N));
Set_SCIL_Entity (SCIL_Node, Etype (Right_Type));
Set_SCIL_Tag_Value (SCIL_Node, Obj_Tag);
end if;
Result := New_Node;
end if;
-- Right_Type is not a class-wide type
else
-- No need to check the tag of the object if Right_Typ is abstract
if Is_Abstract_Type (Right_Type) then
Result := New_Reference_To (Standard_False, Loc);
else
Result :=
Make_Op_Eq (Loc,
Left_Opnd => Obj_Tag,
Right_Opnd =>
New_Reference_To
(Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc));
end if;
end if;
end Tagged_Membership;
------------------------------
-- Unary_Op_Validity_Checks --
------------------------------
procedure Unary_Op_Validity_Checks (N : Node_Id) is
begin
if Validity_Checks_On and Validity_Check_Operands then
Ensure_Valid (Right_Opnd (N));
end if;
end Unary_Op_Validity_Checks;
end Exp_Ch4;