From 2f150833b4edaad314f61a91d46b7f871661df15 Mon Sep 17 00:00:00 2001
From: Eric Botcazou <ebotcazou@adacore.com>
Date: Thu, 28 Sep 2023 16:25:31 +0200
Subject: [PATCH] ada: Fix internal error on too large representation clause
for small component
This is a small bug present on strict-alignment platforms for questionable
representation clauses.
gcc/ada/
* gcc-interface/decl.cc (inline_status_for_subprog): Minor tweak.
(gnat_to_gnu_field): Try harder to get a packable form of the type
for a bitfield.
---
gcc/ada/gcc-interface/decl.cc | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc
index 5e16b56217c0..20ab185d5778 100644
--- a/gcc/ada/gcc-interface/decl.cc
+++ b/gcc/ada/gcc-interface/decl.cc
@@ -5114,7 +5114,7 @@ inline_status_for_subprog (Entity_Id subprog)
tree gnu_type;
/* This is a kludge to work around a pass ordering issue: for small
- record types with many components, i.e. typically bit-fields, the
+ record types with many components, i.e. typically bitfields, the
initialization routine can contain many assignments that will be
merged by the GIMPLE store merging pass. But this pass runs very
late in the pipeline, in particular after the inlining decisions
@@ -7702,6 +7702,18 @@ gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed,
gnu_field_type = maybe_pad_type (gnu_field_type, gnu_size, 0, gnat_field,
false, definition, true);
+ /* For a bitfield, if the type still has BLKmode, try again to change it
+ to an integral mode form. This may be necessary on strict-alignment
+ platforms with a size clause that is much larger than the field type,
+ because maybe_pad_type has preserved the alignment of the field type,
+ which may be too low for the new size. */
+ if (!needs_strict_alignment
+ && RECORD_OR_UNION_TYPE_P (gnu_field_type)
+ && !TYPE_FAT_POINTER_P (gnu_field_type)
+ && TYPE_MODE (gnu_field_type) == BLKmode
+ && is_bitfield)
+ gnu_field_type = make_packable_type (gnu_field_type, true, 1);
+
/* If a padding record was made, declare it now since it will never be
declared otherwise. This is necessary to ensure that its subtrees
are properly marked. */
--
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