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| author | Steve Baird <baird@adacore.com> | 2024-03-18 14:35:33 -0700 |
|---|---|---|
| committer | Marc Poulhiès <poulhies@adacore.com> | 2024-05-20 09:47:03 +0200 |
| commit | caaf20e2678117861a7a4d1da712be91a94596b1 (patch) | |
| tree | 0494f6647de1f4d340511fcc75c2aa0a480d9de3 /gcc/ada | |
| parent | eef3025547ce55cbf6a9018b495ef5c9a562047a (diff) | |
| download | gcc-caaf20e2678117861a7a4d1da712be91a94596b1.zip gcc-caaf20e2678117861a7a4d1da712be91a94596b1.tar.gz gcc-caaf20e2678117861a7a4d1da712be91a94596b1.tar.bz2 | |
ada: Reject too-strict alignment specifications.
For a discrete (or fixed-point) type T, GNAT requires that T'Object_Size
shall be a multiple of T'Alignment * 8 .
GNAT also requires that T'Object_Size shall be no larger than
Standard'Max_Integer_Size.
For a sufficiently-large alignment specification, these requirements can
conflict.
The conflict is resolved by rejecting such alignment specifications (which
were previously accepted in some cases).
gcc/ada/
* freeze.adb (Adjust_Esize_For_Alignment): Assert that a valid
Alignment specification cannot result in adjusting the given
type's Esize to be larger than System_Max_Integer_Size.
* sem_ch13.adb (Analyze_Attribute_Definition_Clause): In analyzing
an Alignment specification, enforce the rule that a specified
Alignment value for a discrete or fixed-point type shall not be
larger than System_Max_Integer_Size / 8 .
gcc/testsuite/ChangeLog:
* gnat.dg/specs/alignment2.ads: Adjust.
* gnat.dg/specs/alignment2_bis.ads: New test.
Diffstat (limited to 'gcc/ada')
| -rw-r--r-- | gcc/ada/freeze.adb | 8 | ||||
| -rw-r--r-- | gcc/ada/sem_ch13.adb | 15 |
2 files changed, 21 insertions, 2 deletions
diff --git a/gcc/ada/freeze.adb b/gcc/ada/freeze.adb index a980c7e..26e9d01 100644 --- a/gcc/ada/freeze.adb +++ b/gcc/ada/freeze.adb @@ -303,8 +303,12 @@ package body Freeze is if Known_Esize (Typ) and then Known_Alignment (Typ) then Align := Alignment_In_Bits (Typ); - if Align > Esize (Typ) and then Align <= System_Max_Integer_Size then - Set_Esize (Typ, Align); + if Align > Esize (Typ) then + if Align > System_Max_Integer_Size then + pragma Assert (Serious_Errors_Detected > 0); + else + Set_Esize (Typ, Align); + end if; end if; end if; end Adjust_Esize_For_Alignment; diff --git a/gcc/ada/sem_ch13.adb b/gcc/ada/sem_ch13.adb index 13bf93c..59c8002 100644 --- a/gcc/ada/sem_ch13.adb +++ b/gcc/ada/sem_ch13.adb @@ -6573,6 +6573,21 @@ package body Sem_Ch13 is ("alignment for & set to Maximum_Aligment??", Nam); Set_Alignment (U_Ent, Max_Align); + -- Because Object_Size must be multiple of Alignment (in bits), + -- System_Max_Integer_Size limit for discrete and fixed point + -- types implies a limit on alignment for such types. + + elsif (Is_Discrete_Type (U_Ent) + or else Is_Fixed_Point_Type (U_Ent)) + and then Align > System_Max_Integer_Size / System_Storage_Unit + then + Error_Msg_N + ("specified alignment too large for discrete or fixed " & + "point type", Expr); + Set_Alignment + (U_Ent, UI_From_Int (System_Max_Integer_Size / + System_Storage_Unit)); + -- All other cases else |