From c2ab04f9e57d248094640e87fdfe3f9454a9cd5d Mon Sep 17 00:00:00 2001
From: nathan <nathan@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 28 Nov 2005 10:34:30 +0000
Subject: [PATCH] .: PR c++/21166 * c-decl.c (finish_struct): Only set
DECL_PACKED on a field when its natural alignment is > BITS_PER_UNIT.
* stor-layout.c (finalize_type_size): Revert my patch of 2005-08-08.
* c-common.c (handle_packed_attribute): Ignore packing on a field whose
type is naturally char aligned. cp: PR c++/21166 * class.c
(check_field_decls): Only set DECL_PACKED on a field when its natural
alignment is > BITS_PER_UNIT.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@107599 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/ChangeLog | 9 +++++++++
gcc/c-common.c | 14 ++++++++++----
gcc/c-decl.c | 4 +++-
gcc/cp/ChangeLog | 6 ++++++
gcc/cp/class.c | 2 +-
gcc/stor-layout.c | 11 -----------
6 files changed, 29 insertions(+), 17 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a1b40fdf81ee..35d08ba1185a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2005-11-28 Nathan Sidwell <nathan@codesourcery.com>
+
+ PR c++/21166
+ * c-decl.c (finish_struct): Only set DECL_PACKED on a field
+ when its natural alignment is > BITS_PER_UNIT.
+ * stor-layout.c (finalize_type_size): Revert my patch of 2005-08-08.
+ * c-common.c (handle_packed_attribute): Ignore packing on a field
+ whose type is naturally char aligned.
+
2005-11-28 Richard Guenther <rguenther@suse.de>
* c-common.c (strict_aliasing_warning): Handle all
diff --git a/gcc/c-common.c b/gcc/c-common.c
index b416a5d3648a..43c147b30686 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -4065,17 +4065,23 @@ handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args),
struct Foo {
struct Foo const *ptr; // creates a variant w/o packed flag
- } __ attribute__((packed)); // packs it now.
- */
+ } __ attribute__((packed)); // packs it now.
+ */
tree probe;
for (probe = *node; probe; probe = TYPE_NEXT_VARIANT (probe))
TYPE_PACKED (probe) = 1;
}
-
}
else if (TREE_CODE (*node) == FIELD_DECL)
- DECL_PACKED (*node) = 1;
+ {
+ if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT)
+ warning (OPT_Wattributes,
+ "%qE attribute ignored for field of type %qT",
+ name, TREE_TYPE (*node));
+ else
+ DECL_PACKED (*node) = 1;
+ }
/* We can't set DECL_PACKED for a VAR_DECL, because the bit is
used for DECL_REGISTER. It wouldn't mean anything anyway.
We can't set DECL_PACKED on the type of a TYPE_DECL, because
diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index a86cfdc01b64..44e03abacdcc 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -5326,7 +5326,9 @@ finish_struct (tree t, tree fieldlist, tree attributes)
for (x = fieldlist; x; x = TREE_CHAIN (x))
{
DECL_CONTEXT (x) = t;
- DECL_PACKED (x) |= TYPE_PACKED (t);
+
+ if (TYPE_PACKED (t) && TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
+ DECL_PACKED (x) = 1;
/* If any field is const, the structure type is pseudo-const. */
if (TREE_READONLY (x))
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 71f7d0bb44da..785c926e6574 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2005-11-28 Nathan Sidwell <nathan@codesourcery.com>
+
+ PR c++/21166
+ * class.c (check_field_decls): Only set DECL_PACKED on a field
+ when its natural alignment is > BITS_PER_UNIT.
+
2005-11-27 Volker Reichelt <reichelt@igpm.rwth-aachen.de>
PR c++/24979
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 7c43d3b242ed..647b7cb67b99 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -2801,7 +2801,7 @@ check_field_decls (tree t, tree *access_decls,
(0,
"ignoring packed attribute on unpacked non-POD field %q+#D",
x);
- else
+ else if (TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
DECL_PACKED (x) = 1;
}
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
index 97104d1af6ba..54ab5ac14a50 100644
--- a/gcc/stor-layout.c
+++ b/gcc/stor-layout.c
@@ -1495,8 +1495,6 @@ finalize_type_size (tree type)
void
finish_record_layout (record_layout_info rli, int free_p)
{
- tree field;
-
/* Compute the final size. */
finalize_record_size (rli);
@@ -1506,15 +1504,6 @@ finish_record_layout (record_layout_info rli, int free_p)
/* Perform any last tweaks to the TYPE_SIZE, etc. */
finalize_type_size (rli->t);
- /* We might be able to clear DECL_PACKED on any members that happen
- to be suitably aligned (not forgetting the alignment of the type
- itself). */
- for (field = TYPE_FIELDS (rli->t); field; field = TREE_CHAIN (field))
- if (TREE_CODE (field) == FIELD_DECL && DECL_PACKED (field)
- && DECL_OFFSET_ALIGN (field) >= TYPE_ALIGN (TREE_TYPE (field))
- && TYPE_ALIGN (rli->t) >= TYPE_ALIGN (TREE_TYPE (field)))
- DECL_PACKED (field) = 0;
-
/* Lay out any static members. This is done now because their type
may use the record's type. */
while (rli->pending_statics)
--
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