re PR c/83966 (ICE in check_function_arguments at gcc/c-family/c-common.c:5617)

	PR c/83966
	* c-format.c (check_function_format): Check current_function_decl.

	* gcc.dg/format/Wsuggest-attribute-1.c: New test.

From-SVN: r257159

gcc/c-family/ChangeLog

+2018-01-29  Marek Polacek  <polacek@redhat.com>
+
+	PR c/83966
+	* c-format.c (check_function_format): Check current_function_decl.
+
 2018-01-27  Jakub Jelinek  <jakub@redhat.com>
 
 	* c-cppbuiltin.c (c_cpp_builtins): Use ggc_strdup for the fp_suffix

gcc/c-family/c-format.c

@@ -1110,7 +1110,9 @@ check_function_format (tree attrs, int nargs, tree *argarray,
 	     from the format attribute if the called function is decorated
 	     with it.  Avoid using calls with string literal formats for
 	     guidance since those are unlikely to be viable candidates.  */
-	  if (warn_suggest_attribute_format && info.first_arg_num == 0
+	  if (warn_suggest_attribute_format
+	      && current_function_decl != NULL_TREE
+	      && info.first_arg_num == 0
 	      && (format_types[info.format_type].flags
 		  & (int) FMT_FLAG_ARG_CONVERT)
 	      /* c_strlen will fail for a function parameter but succeed

gcc/testsuite/ChangeLog

+2018-01-29  Marek Polacek  <polacek@redhat.com>
+
+	PR c/83966
+	* gcc.dg/format/Wsuggest-attribute-1.c: New test.
+
 2018-01-29  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/84057

gcc/testsuite/gcc.dg/format/Wsuggest-attribute-1.c

+/* PR c/83966 */
+/* { dg-do compile } */
+/* { dg-options "-Wsuggest-attribute=format" } */
+
+#include "format.h"
+
+va_list va;
+const char *f;
+__typeof (vsnprintf ("foo", 0U, f, va)) T;