From 7e4aeb3297fc305dc887732c5d03360a7677fba5 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 11 Sep 2007 11:07:59 -0400
Subject: [PATCH] re PR middle-end/27945 (Packed struct of variable length has
wrong size)
PR middle-end/27945
* stor-layout.c (layout_decl): Do pack variable size fields.
From-SVN: r128380
---
gcc/ChangeLog | 5 +++++
gcc/stor-layout.c | 15 ++++-----------
gcc/testsuite/gcc.dg/packed-vla.c | 30 ++++++++++++++++++++++++++++++
3 files changed, 39 insertions(+), 11 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/packed-vla.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index add575350f53..ac74a0e54c6e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2007-09-11 Jason Merrill <jason@redhat.com>
+
+ PR middle-end/27945
+ * stor-layout.c (layout_decl): Do pack variable size fields.
+
2007-09-11 Maxim Kuvyrkov <maxim@codesourcery.com>
* config/m68k/predicates.md (movsi_const0_operand,
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
index ea658a86aa0f..f149e68d5377 100644
--- a/gcc/stor-layout.c
+++ b/gcc/stor-layout.c
@@ -414,18 +414,11 @@ layout_decl (tree decl, unsigned int known_align)
else
do_type_align (type, decl);
- /* If the field is of variable size, we can't misalign it since we
- have no way to make a temporary to align the result. But this
- isn't an issue if the decl is not addressable. Likewise if it
- is of unknown size.
-
- Note that do_type_align may set DECL_USER_ALIGN, so we need to
- check old_user_align instead. */
+ /* If the field is packed and not explicitly aligned, give it the
+ minimum alignment. Note that do_type_align may set
+ DECL_USER_ALIGN, so we need to check old_user_align instead. */
if (packed_p
- && !old_user_align
- && (DECL_NONADDRESSABLE_P (decl)
- || DECL_SIZE_UNIT (decl) == 0
- || TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST))
+ && !old_user_align)
DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), BITS_PER_UNIT);
if (! packed_p && ! DECL_USER_ALIGN (decl))
diff --git a/gcc/testsuite/gcc.dg/packed-vla.c b/gcc/testsuite/gcc.dg/packed-vla.c
new file mode 100644
index 000000000000..d5fef5c4ccfb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/packed-vla.c
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "" } */
+
+extern int printf (const char *, ...);
+extern void abort ();
+
+int func(int levels)
+{
+ struct bar {
+ unsigned char a;
+ int b[levels];
+ } __attribute__ ((__packed__)) bar;
+
+ struct foo {
+ unsigned char a;
+ int b[4];
+ } __attribute__ ((__packed__)) foo;
+
+ printf("foo %d\n", sizeof(foo));
+ printf("bar %d\n", sizeof(bar));
+
+ if (sizeof (foo) != sizeof (bar))
+ abort ();
+}
+
+int main()
+{
+ func(4);
+ return 0;
+}
--
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