re PR c/65040 (gcc-5 -Wformat broken)

	PR c/65040
	* c-format.c (check_format_types): Don't warn about different
	signedness if the original value is in the range of WANTED_TYPE.

	* c-c++-common/pr65040.c: New test.

From-SVN: r220677

4 files changed, 47 insertions, 2 deletions

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index c63384b..804c1db 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,9 @@
+2015-02-13  Marek Polacek  <polacek@redhat.com>
+
+	PR c/65040
+	* c-format.c (check_format_types): Don't warn about different
+	signedness if the original value is in the range of WANTED_TYPE.
+
 2015-02-12  Jason Merrill  <jason@redhat.com>
 
 	PR c++/64956
diff --git a/gcc/c-family/c-format.c b/gcc/c-family/c-format.c
index faaca09..2f49b2d 100644
--- a/gcc/c-family/c-format.c
+++ b/gcc/c-family/c-format.c
@@ -2456,8 +2456,7 @@ check_format_types (location_t loc, format_wanted_type *types)
       cur_type = TYPE_MAIN_VARIANT (cur_type);
 
       /* Check whether the argument type is a character type.  This leniency
-	 only applies to certain formats, flagged with 'c'.
-      */
+	 only applies to certain formats, flagged with 'c'.  */
       if (types->char_lenient_flag)
 	char_type_flag = (cur_type == char_type_node
 			  || cur_type == signed_char_type_node
@@ -2486,6 +2485,20 @@ check_format_types (location_t loc, format_wanted_type *types)
 	      ? wanted_type == c_common_unsigned_type (cur_type)
 	      : wanted_type == c_common_signed_type (cur_type)))
 	continue;
+      /* Don't warn about differences merely in signedness if we know
+	 that the current type is integer-promoted and its original type
+	 was unsigned such as that it is in the range of WANTED_TYPE.  */
+      if (TREE_CODE (wanted_type) == INTEGER_TYPE
+	  && TREE_CODE (cur_type) == INTEGER_TYPE
+	  && warn_format_signedness
+	  && TYPE_UNSIGNED (wanted_type)
+	  && TREE_CODE (cur_param) == NOP_EXPR)
+	{
+	  tree t = TREE_TYPE (TREE_OPERAND (cur_param, 0));
+	  if (TYPE_UNSIGNED (t)
+	      && cur_type == lang_hooks.types.type_promotes_to (t))
+	    continue;
+	}
       /* Likewise, "signed char", "unsigned char" and "char" are
 	 equivalent but the above test won't consider them equivalent.  */
       if (wanted_type == char_type_node
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 729f92d..d958264 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-13  Marek Polacek  <polacek@redhat.com>
+
+	PR c/65040
+	* c-c++-common/pr65040.c: New test.
+
 2015-02-13  Bin Cheng  <bin.cheng@arm.com>
 
 	PR tree-optimization/64705
diff --git a/gcc/testsuite/c-c++-common/pr65040.c b/gcc/testsuite/c-c++-common/pr65040.c
new file mode 100644
index 0000000..80da8f9
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr65040.c
@@ -0,0 +1,21 @@
+/* PR c/65040 */
+/* { dg-do compile } */
+/* { dg-options "-Wformat -Wformat-signedness" } */
+
+unsigned char uc;
+signed char sc;
+unsigned short us;
+signed short ss;
+unsigned int u;
+int i;
+
+void
+foo (void)
+{
+  __builtin_printf ("%u\n", uc); /* { dg-bogus "expects argument of type" } */
+  __builtin_printf ("%u\n", sc); /* { dg-warning "expects argument of type" } */
+  __builtin_printf ("%u\n", us); /* { dg-bogus "expects argument of type" } */
+  __builtin_printf ("%u\n", ss); /* { dg-warning "expects argument of type" } */
+  __builtin_printf ("%u\n", u); /* { dg-bogus "expects argument of type" } */
+  __builtin_printf ("%u\n", i); /* { dg-warning "expects argument of type" } */
+}