From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 30 Aug 2019 12:38:31 +0000 (+0200)
Subject: backport: re PR c++/90108 (ICE: Segmentation fault (in c_tree_chain_next))
X-Git-Tag: releases/gcc-7.5.0~213
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=79797c978183ab550eb109ea4e70ad4d214aa482;p=thirdparty%2Fgcc.git

backport: re PR c++/90108 (ICE: Segmentation fault (in c_tree_chain_next))

	Backported from mainline
	2019-04-19  Jakub Jelinek  <jakub@redhat.com>

	PR c++/90108
	* c-decl.c (merge_decls): If remove is main variant and
	DECL_ORIGINAL_TYPE is some other type, remove a DECL_ORIGINAL_TYPE
	variant that has newdecl as TYPE_NAME if any.

	* decl.c (duplicate_decls): If remove is main variant and
	DECL_ORIGINAL_TYPE is some other type, remove a DECL_ORIGINAL_TYPE
	variant that has newdecl as TYPE_NAME if any.

	* c-c++-common/pr90108.c: New test.

From-SVN: r275150
---

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index a861feeac2ee..394457213f78 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,6 +1,13 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-04-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/90108
+	* c-decl.c (merge_decls): If remove is main variant and
+	DECL_ORIGINAL_TYPE is some other type, remove a DECL_ORIGINAL_TYPE
+	variant that has newdecl as TYPE_NAME if any.
+
 	2019-04-12  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/89933
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 11c63af89ed7..964d5f1a2d22 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -2349,7 +2349,24 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
 	{
 	  tree remove = TREE_TYPE (newdecl);
 	  if (TYPE_MAIN_VARIANT (remove) == remove)
-	    gcc_assert (TYPE_NEXT_VARIANT (remove) == NULL_TREE);
+	    {
+	      gcc_assert (TYPE_NEXT_VARIANT (remove) == NULL_TREE);
+	      /* If remove is the main variant, no need to remove that
+		 from the list.  One of the DECL_ORIGINAL_TYPE
+		 variants, e.g. created for aligned attribute, might still
+		 refer to the newdecl TYPE_DECL though, so remove that one
+		 in that case.  */
+	      if (DECL_ORIGINAL_TYPE (newdecl)
+		  && DECL_ORIGINAL_TYPE (newdecl) != remove)
+		for (tree t = TYPE_MAIN_VARIANT (DECL_ORIGINAL_TYPE (newdecl));
+		     t; t = TYPE_MAIN_VARIANT (t))
+		  if (TYPE_NAME (TYPE_NEXT_VARIANT (t)) == newdecl)
+		    {
+		      TYPE_NEXT_VARIANT (t)
+			= TYPE_NEXT_VARIANT (TYPE_NEXT_VARIANT (t));
+		      break;
+		    }
+	    }	    
 	  else
 	    for (tree t = TYPE_MAIN_VARIANT (remove); ;
 		 t = TYPE_NEXT_VARIANT (t))
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 742b0e428440..9712503fe9e4 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,6 +1,13 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-04-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/90108
+	* decl.c (duplicate_decls): If remove is main variant and
+	DECL_ORIGINAL_TYPE is some other type, remove a DECL_ORIGINAL_TYPE
+	variant that has newdecl as TYPE_NAME if any.
+
 	2019-04-12  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/89933
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 1ad6ad8fae48..56e4c31e242e 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -2131,7 +2131,24 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
 	    {
 	      tree remove = TREE_TYPE (newdecl);
 	      if (TYPE_MAIN_VARIANT (remove) == remove)
-		gcc_assert (TYPE_NEXT_VARIANT (remove) == NULL_TREE);
+		{
+		  gcc_assert (TYPE_NEXT_VARIANT (remove) == NULL_TREE);
+		  /* If remove is the main variant, no need to remove that
+		     from the list.  One of the DECL_ORIGINAL_TYPE
+		     variants, e.g. created for aligned attribute, might still
+		     refer to the newdecl TYPE_DECL though, so remove that one
+		     in that case.  */
+		  if (tree orig = DECL_ORIGINAL_TYPE (newdecl))
+		    if (orig != remove)
+		      for (tree t = TYPE_MAIN_VARIANT (orig); t;
+			   t = TYPE_MAIN_VARIANT (t))
+			if (TYPE_NAME (TYPE_NEXT_VARIANT (t)) == newdecl)
+			  {
+			    TYPE_NEXT_VARIANT (t)
+			      = TYPE_NEXT_VARIANT (TYPE_NEXT_VARIANT (t));
+			    break;
+			  }
+		}	    
 	      else
 		for (tree t = TYPE_MAIN_VARIANT (remove); ;
 		     t = TYPE_NEXT_VARIANT (t))
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 978d725437ec..9b51773a0d31 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2019-04-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/90108
+	* c-c++-common/pr90108.c: New test.
+
 	2019-04-16  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/90082
diff --git a/gcc/testsuite/c-c++-common/pr90108.c b/gcc/testsuite/c-c++-common/pr90108.c
new file mode 100644
index 000000000000..fa5b8461aaea
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr90108.c
@@ -0,0 +1,6 @@
+/* PR c++/90108 */
+/* { dg-do compile } */
+/* { dg-options "--param ggc-min-heapsize=0" } */
+
+typedef unsigned int a __attribute__ ((__aligned__(8), __may_alias__));
+typedef unsigned int a __attribute__ ((__aligned__(8), __may_alias__));