re PR bootstrap/67030 (ARM bootstrap failure due to [-Werror=tautological-compare])

	PR bootstrap/67030
	* c-common.c (warn_tautological_cmp): Don't warn for macro expansion.

	* c-c++-common/Wtautological-compare-2.c: New test.

From-SVN: r226264

gcc/c-family/ChangeLog

 2015-07-27  Marek Polacek  <polacek@redhat.com>
 
+	PR bootstrap/67030
+	* c-common.c (warn_tautological_cmp): Don't warn for macro expansion.
+
+2015-07-27  Marek Polacek  <polacek@redhat.com>
+
 	PR c++/66555
 	PR c/54979
 	* c-common.c (find_array_ref_with_const_idx_r): New function.

gcc/c-family/c-common.c

@@ -1890,6 +1890,12 @@ warn_tautological_cmp (location_t loc, enum tree_code code, tree lhs, tree rhs)
   if (TREE_CODE_CLASS (code) != tcc_comparison)
     return;
 
+  /* Don't warn for various macro expansions.  */
+  if (from_macro_expansion_at (loc)
+      || from_macro_expansion_at (EXPR_LOCATION (lhs))
+      || from_macro_expansion_at (EXPR_LOCATION (rhs)))
+    return;
+
   /* We do not warn for constants because they are typical of macro
      expansions that test for features, sizeof, and similar.  */
   if (CONSTANT_CLASS_P (lhs) || CONSTANT_CLASS_P (rhs))

gcc/testsuite/ChangeLog

+2015-07-27  Marek Polacek  <polacek@redhat.com>
+
+	PR bootstrap/67030
+	* c-c++-common/Wtautological-compare-2.c: New test.
+
 2015-07-27  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/66232

gcc/testsuite/c-c++-common/Wtautological-compare-2.c

+/* PR bootstrap/67030 */
+/* { dg-do compile } */
+/* { dg-options "-Wtautological-compare" } */
+
+extern int foo (void);
+
+#define A a
+#define B A
+#define FOO (A > B)
+
+void
+fn1 (int a)
+{
+  if (FOO);
+}