From: Martin Liska <mliska@suse.cz>
Date: Wed, 7 Mar 2018 09:43:23 +0000 (+0100)
Subject: Backport r257183
X-Git-Tag: releases/gcc-6.5.0~478
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=04971ccc95566b206a1b87645cbb8435a0bd8037;p=thirdparty%2Fgcc.git

Backport r257183

2018-03-07  Martin Liska  <mliska@suse.cz>

	Backport from mainline
	2018-01-30  Jan Hubicka  <hubicka@ucw.cz>

	PR lto/83954
	* lto-symtab.c (warn_type_compatibility_p): Silence false positive
	for type match warning on arrays of pointers.
2018-03-07  Martin Liska  <mliska@suse.cz>

	Backport from mainline
	2018-01-30  Jan Hubicka  <hubicka@ucw.cz>

	PR lto/83954
	* gcc.dg/lto/pr83954.h: New testcase.
	* gcc.dg/lto/pr83954_0.c: New testcase.
	* gcc.dg/lto/pr83954_1.c: New testcase.

From-SVN: r258319
---

diff --git a/gcc/lto/ChangeLog b/gcc/lto/ChangeLog
index 940e6d2662ec..b2cbe74fa6b4 100644
--- a/gcc/lto/ChangeLog
+++ b/gcc/lto/ChangeLog
@@ -1,3 +1,12 @@
+2018-03-07  Martin Liska  <mliska@suse.cz>
+
+	Backport from mainline
+	2018-01-30  Jan Hubicka  <hubicka@ucw.cz>
+
+	PR lto/83954
+	* lto-symtab.c (warn_type_compatibility_p): Silence false positive
+	for type match warning on arrays of pointers.
+
 2018-03-07  Martin Liska  <mliska@suse.cz>
 
 	Backport from mainline
diff --git a/gcc/lto/lto-symtab.c b/gcc/lto/lto-symtab.c
index 94b919b53e6e..395dca479291 100644
--- a/gcc/lto/lto-symtab.c
+++ b/gcc/lto/lto-symtab.c
@@ -280,11 +280,22 @@ warn_type_compatibility_p (tree prevailing_type, tree type,
       alias_set_type set1 = get_alias_set (type);
       alias_set_type set2 = get_alias_set (prevailing_type);
 
-      if (set1 && set2 && set1 != set2 
-          && (!POINTER_TYPE_P (type) || !POINTER_TYPE_P (prevailing_type)
+      if (set1 && set2 && set1 != set2)
+	{
+          tree t1 = type, t2 = prevailing_type;
+
+	  /* Alias sets of arrays are the same as alias sets of the inner
+	     types.  */
+	  while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
+	    {
+	      t1 = TREE_TYPE (t1);
+	      t2 = TREE_TYPE (t2);
+	    }
+          if ((!POINTER_TYPE_P (t1) || !POINTER_TYPE_P (t2))
 	      || (set1 != TYPE_ALIAS_SET (ptr_type_node)
-		  && set2 != TYPE_ALIAS_SET (ptr_type_node))))
-        lev |= 5;
+		  && set2 != TYPE_ALIAS_SET (ptr_type_node)))
+             lev |= 5;
+	}
     }
 
   return lev;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 705b89d20d5e..e19c92e95487 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,13 @@
+2018-03-07  Martin Liska  <mliska@suse.cz>
+
+	Backport from mainline
+	2018-01-30  Jan Hubicka  <hubicka@ucw.cz>
+
+	PR lto/83954
+	* gcc.dg/lto/pr83954.h: New testcase.
+	* gcc.dg/lto/pr83954_0.c: New testcase.
+	* gcc.dg/lto/pr83954_1.c: New testcase.
+
 2018-03-06  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/56667
diff --git a/gcc/testsuite/gcc.dg/lto/pr83954.h b/gcc/testsuite/gcc.dg/lto/pr83954.h
new file mode 100644
index 000000000000..e01554025041
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr83954.h
@@ -0,0 +1,3 @@
+struct foo;
+extern struct foo *FOO_PTR_ARR[1];
+
diff --git a/gcc/testsuite/gcc.dg/lto/pr83954_0.c b/gcc/testsuite/gcc.dg/lto/pr83954_0.c
new file mode 100644
index 000000000000..065a31dab800
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr83954_0.c
@@ -0,0 +1,8 @@
+/* { dg-lto-do link } */
+#include "pr83954.h"
+
+int main() {
+  // just to prevent symbol removal
+  FOO_PTR_ARR[1] = 0;
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/lto/pr83954_1.c b/gcc/testsuite/gcc.dg/lto/pr83954_1.c
new file mode 100644
index 000000000000..61b40fc77598
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr83954_1.c
@@ -0,0 +1,7 @@
+#include "pr83954.h"
+
+struct foo {
+ int x;
+};
+struct foo *FOO_PTR_ARR[1] = { 0 };
+