* [COMMITTED] ada: Compiler crash on early alignment clause
@ 2023-11-07 9:20 Marc Poulhiès
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From: Marc Poulhiès @ 2023-11-07 9:20 UTC (permalink / raw)
To: gcc-patches; +Cc: Bob Duff
From: Bob Duff <duff@adacore.com>
This patch fixes a bug: if "for T'Alignment use..." is followed
by "for T use (<enum rep>);" the compiler crashes. A workaround is
to move the alignment clause after the enumeration rep clause.
gcc/ada/
* sem_ch13.ads (Set_Enum_Esize): Do not set alignment.
* sem_ch13.adb (Set_Enum_Esize): Do not set alignment. Archaeology
seems to show that this line of code dates from when "Alignment =
0" meant "the Alignment is not known at compile time" and "the
Alignment is not yet known at compile time" as well as "the
Alignment is zero". In any case, it seems to be unnecessary, and
in this case harmful, because gigi would crash. Alignment_Clause
is set (because there is one), so gigi would query the Alignment,
but Alignment was destroyed.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/sem_ch13.adb | 2 --
gcc/ada/sem_ch13.ads | 3 +--
2 files changed, 1 insertion(+), 4 deletions(-)
diff --git a/gcc/ada/sem_ch13.adb b/gcc/ada/sem_ch13.adb
index 5747ee9c539..302fab74757 100644
--- a/gcc/ada/sem_ch13.adb
+++ b/gcc/ada/sem_ch13.adb
@@ -17381,8 +17381,6 @@ package body Sem_Ch13 is
Sz : Unat;
begin
- Reinit_Alignment (T);
-
-- Find the minimum standard size (8,16,32,64,128) that fits
Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
diff --git a/gcc/ada/sem_ch13.ads b/gcc/ada/sem_ch13.ads
index 1386096535e..555d302fb10 100644
--- a/gcc/ada/sem_ch13.ads
+++ b/gcc/ada/sem_ch13.ads
@@ -79,8 +79,7 @@ package Sem_Ch13 is
procedure Set_Enum_Esize (T : Entity_Id);
-- This routine sets the Esize field for an enumeration type T, based
-- on the current representation information available for T. Note that
- -- the setting of the RM_Size field is not affected. This routine also
- -- initializes the alignment field to zero.
+ -- the setting of the RM_Size field is not affected.
Unknown_Minimum_Size : constant Nonzero_Int := -1;
--
2.42.0
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