From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 14 Feb 2012 23:34:34 +0000 (+0100)
Subject: backport: re PR c/52181 (merge_decls doesn't handle DECL_USER_ALIGN properly)
X-Git-Tag: releases/gcc-4.6.3~83
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=337d93e142a4f4702424aa930007e6f6dbf98477;p=thirdparty%2Fgcc.git

backport: re PR c/52181 (merge_decls doesn't handle DECL_USER_ALIGN properly)

	Backported from mainline
	2012-02-14  Jakub Jelinek  <jakub@redhat.com>

	PR c/52181
	* c-decl.c (merge_decls): Copy DECL_USER_ALIGN bit from olddecl to
	newdecl.

	* decl.c (duplicate_decls): If olddecl has bigger DECL_ALIGN than
	newdecl, copy DECL_ALIGN to newdecl and or DECL_USER_ALIGN bits.

	* c-c++-common/pr52181.c: New test.

From-SVN: r184242
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 48feadfadd0d..e458e08ac4eb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,12 @@
 2012-02-14  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2012-02-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/52181
+	* c-decl.c (merge_decls): Copy DECL_USER_ALIGN bit from olddecl to
+	newdecl.
+
 	2012-02-13  Jakub Jelinek  <jakub@redhat.com>
 
 	* cselib.c (dump_cselib_val): Don't assume l->setting_insn is
diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index b148f5e22f71..6d6331343290 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -2436,6 +2436,7 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
     memcpy ((char *) olddecl + sizeof (struct tree_common),
 	    (char *) newdecl + sizeof (struct tree_common),
 	    sizeof (struct tree_decl_common) - sizeof (struct tree_common));
+    DECL_USER_ALIGN (olddecl) = DECL_USER_ALIGN (newdecl);
     switch (TREE_CODE (olddecl))
       {
       case FUNCTION_DECL:
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 15e93a5ed804..4eb9ec48954e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,12 @@
+2012-02-14  Jakub Jelinek  <jakub@redhat.com>
+
+	Backported from mainline
+	2012-02-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/52181
+	* decl.c (duplicate_decls): If olddecl has bigger DECL_ALIGN than
+	newdecl, copy DECL_ALIGN to newdecl and or DECL_USER_ALIGN bits.
+
 2012-02-09  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index a2e52613fce9..6b6f158491eb 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2154,7 +2154,12 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
       SET_DECL_INIT_PRIORITY (olddecl, DECL_INIT_PRIORITY (newdecl));
       DECL_HAS_INIT_PRIORITY_P (olddecl) = 1;
     }
-  /* Likewise for DECL_USER_ALIGN and DECL_PACKED.  */
+  /* Likewise for DECL_ALIGN, DECL_USER_ALIGN and DECL_PACKED.  */
+  if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl))
+    {
+      DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl);
+      DECL_USER_ALIGN (newdecl) |= DECL_USER_ALIGN (olddecl);
+    }
   DECL_USER_ALIGN (olddecl) = DECL_USER_ALIGN (newdecl);
   if (TREE_CODE (newdecl) == FIELD_DECL)
     DECL_PACKED (olddecl) = DECL_PACKED (newdecl);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6e546a003aa4..2e19a3d73d51 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2012-02-14  Jakub Jelinek  <jakub@redhat.com>
+
+	Backported from mainline
+	2012-02-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/52181
+	* c-c++-common/pr52181.c: New test.
+
 2012-02-09  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
diff --git a/gcc/testsuite/c-c++-common/pr52181.c b/gcc/testsuite/c-c++-common/pr52181.c
new file mode 100644
index 000000000000..e09bc92fc6f9
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr52181.c
@@ -0,0 +1,13 @@
+/* PR c/52181 */
+/* { dg-do compile } */
+
+extern const int v1[];
+const int __attribute__((aligned(16))) v1[] = { 1 };
+extern const int __attribute__((aligned(16))) v2[];
+const int v2[] = { 1 };
+extern const int __attribute__((aligned(16))) v3[];
+const int __attribute__((aligned(16))) v3[] = { 1 };
+const int __attribute__((aligned(16))) v4[] = { 1 };
+int test[(__alignof__ (v4) != __alignof__ (v1)		/* { dg-bogus "is negative" } */
+	 || __alignof__ (v4) != __alignof__ (v2)
+	 || __alignof__ (v4) != __alignof__ (v3)) ? -1 : 0];