From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 30 Aug 2019 12:36:05 +0000 (+0200)
Subject: backport: re PR c/89933 (ICE in merge_decls, at c/c-decl.c:2517)
X-Git-Tag: releases/gcc-7.5.0~216
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a779fe47e602f02495793bb7d9c7d84e925fedfa;p=thirdparty%2Fgcc.git

backport: re PR c/89933 (ICE in merge_decls, at c/c-decl.c:2517)

	Backported from mainline
	2019-04-12  Jakub Jelinek  <jakub@redhat.com>

	PR c/89933
	* c-decl.c (merge_decls): When newdecl's type is its main variant,
	don't try to remove it from the variant list, but instead assert
	it has no variants.

	* decl.c (duplicate_decls): When newdecl's type is its main variant,
	don't try to remove it from the variant list, but instead assert
	it has no variants.

	* c-c++-common/pr89933.c: New test.

From-SVN: r275147
---

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index e6108f1b3b3b..a861feeac2ee 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,6 +1,13 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-04-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/89933
+	* c-decl.c (merge_decls): When newdecl's type is its main variant,
+	don't try to remove it from the variant list, but instead assert
+	it has no variants.
+
 	2019-03-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/89734
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 8342094f3540..11c63af89ed7 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -2348,13 +2348,16 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
       if (TYPE_NAME (TREE_TYPE (newdecl)) == newdecl)
 	{
 	  tree remove = TREE_TYPE (newdecl);
-	  for (tree t = TYPE_MAIN_VARIANT (remove); ;
-	       t = TYPE_NEXT_VARIANT (t))
-	    if (TYPE_NEXT_VARIANT (t) == remove)
-	      {
-		TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (remove);
-		break;
-	      }
+	  if (TYPE_MAIN_VARIANT (remove) == remove)
+	    gcc_assert (TYPE_NEXT_VARIANT (remove) == NULL_TREE);
+	  else
+	    for (tree t = TYPE_MAIN_VARIANT (remove); ;
+		 t = TYPE_NEXT_VARIANT (t))
+	      if (TYPE_NEXT_VARIANT (t) == remove)
+		{
+		  TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (remove);
+		  break;
+		}
 	}
     }
 
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 300eca80f259..742b0e428440 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,6 +1,13 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-04-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/89933
+	* decl.c (duplicate_decls): When newdecl's type is its main variant,
+	don't try to remove it from the variant list, but instead assert
+	it has no variants.
+
 	2019-03-29  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/89869
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 950e04a66807..1ad6ad8fae48 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2130,13 +2130,16 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
 	  if (TYPE_NAME (TREE_TYPE (newdecl)) == newdecl)
 	    {
 	      tree remove = TREE_TYPE (newdecl);
-	      for (tree t = TYPE_MAIN_VARIANT (remove); ;
-		   t = TYPE_NEXT_VARIANT (t))
-		if (TYPE_NEXT_VARIANT (t) == remove)
-		  {
-		    TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (remove);
-		    break;
-		  }
+	      if (TYPE_MAIN_VARIANT (remove) == remove)
+		gcc_assert (TYPE_NEXT_VARIANT (remove) == NULL_TREE);
+	      else
+		for (tree t = TYPE_MAIN_VARIANT (remove); ;
+		     t = TYPE_NEXT_VARIANT (t))
+		  if (TYPE_NEXT_VARIANT (t) == remove)
+		    {
+		      TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (remove);
+		      break;
+		    }
 	    }
 	}
       else
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 578187377474..46097e5d5ab6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-04-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/89933
+	* c-c++-common/pr89933.c: New test.
+
 	2019-04-09  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/89998
diff --git a/gcc/testsuite/c-c++-common/pr89933.c b/gcc/testsuite/c-c++-common/pr89933.c
new file mode 100644
index 000000000000..870504d4208f
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr89933.c
@@ -0,0 +1,5 @@
+/* PR c/89933 */
+/* { dg-do compile } */
+
+typedef unsigned int a __attribute__ ((__aligned__(8), __may_alias__));
+typedef unsigned int a __attribute__ ((__aligned__(8), __may_alias__));