re PR lto/83954 (LTO: Bogus -Wlto-type-mismatch warning for array of pointer to incom...

	PR lto/83954
	* lto-symtab.c (warn_type_compatibility_p): Silence false positive
	for type match warning on arrays of pointers.
	* 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: r257183

diff --git a/gcc/lto/ChangeLog b/gcc/lto/ChangeLog
index 67679bc861d1b6ae8195dfac393cc0384e71816b..7265b760865671dfa378bc275271fe4b66724813 100644 (file)
--- a/gcc/lto/ChangeLog
+++ b/gcc/lto/ChangeLog
@@ -1,3 +1,9 @@
+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.
+
 2018-01-23  Martin Liska  <mliska@suse.cz>
 
        PR lto/81440

diff --git a/gcc/lto/lto-symtab.c b/gcc/lto/lto-symtab.c
index 0f0b958e98dcd347968e5925a31fb787973778db..0508c5e67502dc26e5086a80710e6082e6b2e1ad 100644 (file)
--- a/gcc/lto/lto-symtab.c
+++ b/gcc/lto/lto-symtab.c
@@ -284,11 +284,22 @@ 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 bfc849ebf89aaaac5b6ecfd6dcad044c6822f3fe..10cc5e849d7a6b66cc2c43a0eb86bee47c2e3ea1 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+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.
+
 2018-01-30  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
        PR bootstrap/84017

diff --git a/gcc/testsuite/gcc.dg/lto/pr83954.h b/gcc/testsuite/gcc.dg/lto/pr83954.h
new file mode 100644 (file)
index 0000000..e015540
--- /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 (file)
index 0000000..5fb7f76
--- /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 (file)
index 0000000..61b40fc
--- /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 };
+