PR target/77837 - missing -Wformat-length warning for %p with null argument on powerpc64

gcc/ChangeLog:

	PR target/77837
	* config/rs6000/linux.h (TARGET_PRINTF_POINTER_FORMAT): Define.
	* config/rs6000/linux64.h (TARGET_PRINTF_POINTER_FORMAT): Likewise.

From-SVN: r241457

gcc/ChangeLog

+2016-10-23  Martin Sebor  <msebor@redhat.com>
+
+	PR target/77837
+	* config/rs6000/linux.h (TARGET_PRINTF_POINTER_FORMAT): Define.
+	* config/rs6000/linux64.h (TARGET_PRINTF_POINTER_FORMAT): Likewise.
+
 2016-10-23  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* config/sparc/sparc.md (cpu_feature): Minor tweak.

gcc/config/rs6000/linux.h

@@ -138,3 +138,7 @@
   || (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 19)
 #define RS6000_GLIBC_ATOMIC_FENV 1
 #endif
+
+/* The format string to which "%p" corresponds.  */
+#undef TARGET_PRINTF_POINTER_FORMAT
+#define TARGET_PRINTF_POINTER_FORMAT linux_printf_pointer_format

gcc/config/rs6000/linux64.h

@@ -640,3 +640,7 @@ extern int dot_symbols;
    enabling the __float128 keyword.  */
 #undef	TARGET_FLOAT128_ENABLE_TYPE
 #define TARGET_FLOAT128_ENABLE_TYPE 1
+
+/* The format string to which "%p" corresponds.  */
+#undef TARGET_PRINTF_POINTER_FORMAT
+#define TARGET_PRINTF_POINTER_FORMAT linux_printf_pointer_format