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ada: Fix internal error on declare expression in expression function

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When the expression function is not a completion, its (return) expression
does not cause freezing so analyzing the declare expression in this context
must not freeze the type of the object.

The change also contains another fix, which makes it so that the compiler
does not evaluate a nonstatic representation attribute of a scalar subtype
in the same context if the subtype is not already frozen.

gcc/ada/

	* sem_attr.adb (Eval_Attribute): Do not proceed in a spec expression
	for nonstatic representation attributes of a scalar subtype when the
	subtype is not frozen.
	* sem_ch3.adb (Analyze_Object_Declaration): Do not freeze the type
	of the object in a spec expression.
This commit is contained in:
Eric Botcazou 2023-11-06 23:34:20 +01:00 • committed by Marc Poulhiès
parent 89ed545585
commit e95a42ec9a
2 changed files with 23 additions and 2 deletions
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20
gcc/ada/sem_attr.adb
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@ -8693,6 +8693,26 @@ package body Sem_Attr is
Set_Raises_Constraint_Error (N);
end if;
-- RM 13.14(8/4): a nonstatic expression in a spec expression does
-- not cause freezing, so the representation attributes cannot be
-- evaluated at this point if the type is not already frozen.
if not Static
and then In_Spec_Expression
and then Id in Attribute_Alignment
| Attribute_Component_Size
| Attribute_Max_Alignment_For_Allocation
| Attribute_Max_Size_In_Storage_Elements
| Attribute_Object_Size
| Attribute_Size
| Attribute_Small
| Attribute_VADS_Size
| Attribute_Value_Size
and then not Is_Frozen (P_Type)
then
return;
end if;
-- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
-- since we can't do anything with unconstrained arrays. In addition,
-- only the First, Last and Length attributes are possibly static.

5
gcc/ada/sem_ch3.adb
View file

@ -4453,7 +4453,8 @@ package body Sem_Ch3 is
-- If not a deferred constant, then the object declaration freezes
-- its type, unless the object is of an anonymous type and has delayed
-- aspects. In that case the type is frozen when the object itself is.
-- aspects (in that case the type is frozen when the object itself is)
-- or the context is a spec expression.
else
Check_Fully_Declared (T, N);
@ -4463,7 +4464,7 @@ package body Sem_Ch3 is
and then Is_Itype (T)
then
Set_Has_Delayed_Freeze (T);
else
elsif not In_Spec_Expression then
Freeze_Before (N, T);
end if;
end if;