re PR c/83989 (-Wrestrict false positive with malloc-style functions)

	PR c/83989
	* gimple-ssa-warn-restrict.c (builtin_memref::builtin_memref): Don't
	use SSA_NAME_VAR as base for SSA_NAMEs with non-NULL SSA_NAME_VAR.

	* c-c++-common/Wrestrict-3.c: New test.

From-SVN: r257086

gcc/ChangeLog

+2018-01-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/83989
+	* gimple-ssa-warn-restrict.c (builtin_memref::builtin_memref): Don't
+	use SSA_NAME_VAR as base for SSA_NAMEs with non-NULL SSA_NAME_VAR.
+
 2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>
 
 	* config/arc/arc-arch.h (arc_tune_attr): Add ARC_TUNE_CORE_3.

gcc/gimple-ssa-warn-restrict.c

@@ -373,9 +373,6 @@ builtin_memref::builtin_memref (tree expr, tree size)
 		  offrange[1] += off;
 		}
 	    }
-
-	if (TREE_CODE (base) == SSA_NAME && SSA_NAME_VAR (base))
-	  base = SSA_NAME_VAR (base);
       }
 
   if (size)

gcc/testsuite/ChangeLog

+2018-01-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/83989
+	* c-c++-common/Wrestrict-3.c: New test.
+
 2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>
 
 	* testsuite/gcc.target/arc/tdelegitimize_addr.c: New test.

gcc/testsuite/c-c++-common/Wrestrict-3.c

+/* PR c/83989 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wrestrict" } */
+
+__attribute__((__malloc__)) extern void *my_malloc (__SIZE_TYPE__);
+void baz (void *);
+
+#define SIZE 32
+
+void
+foo (void)
+{
+  void *recmem = __builtin_malloc (SIZE);
+  baz (recmem);
+  while (1)
+    {
+      void *oldrecmem = recmem;
+      recmem = __builtin_malloc (SIZE);
+      if (!recmem)
+	{
+	  __builtin_free (oldrecmem);
+	  return;
+	}
+      __builtin_memcpy (recmem, oldrecmem, SIZE);	/* { dg-bogus "accessing" } */
+      baz (recmem);
+      __builtin_free (oldrecmem);
+    }
+}
+
+void
+bar (void)
+{
+  void *recmem = my_malloc (SIZE);
+  baz (recmem);
+  while (1)
+    {
+      void *oldrecmem = recmem;
+      recmem = my_malloc (SIZE);
+      if (!recmem)
+	{
+	  __builtin_free (oldrecmem);
+	  return;
+	}
+      __builtin_memcpy (recmem, oldrecmem, SIZE);	/* { dg-bogus "accessing" } */
+      baz (recmem);
+      __builtin_free (oldrecmem);
+    }
+}