cpplex.c (maybe_macroexpand): Warn about function-like macros used in…

cpplex.c (maybe_macroexpand): Warn about function-like macros used in non-function context, if -Wtraditional.

	* cpplex.c (maybe_macroexpand): Warn about function-like
	macros used in non-function context, if -Wtraditional.

From-SVN: r34183

gcc/ChangeLog

+2000-05-25  Zack Weinberg  <zack@wolery.cumb.org>
+
+	* cpplex.c (maybe_macroexpand): Warn about function-like
+	macros used in non-function context, if -Wtraditional.
+
 2000-05-25  Mark Mitchell  <mark@codesourcery.com>
 
 	* recog.c (peephole2_optimize): Use INSN_P.

gcc/cpplex.c

@@ -1687,6 +1687,12 @@ maybe_macroexpand (pfile, written)
 	not_macro_call:
 	  if (macbuf_whitespace)
 	    CPP_PUTC (pfile, ' ');
+
+	  /* K+R treated this as a hard error.  */
+	  if (CPP_OPTION (pfile, warn_traditional))
+	    cpp_warning (pfile,
+	 "traditional C rejects function macro %s in non-function context",
+			 hp->name);
 	  return 0;
 	}
     }

gcc/testsuite/gcc.dg/cpp-tradwarn2.c

+/* K+R rejects use of function-like macros in non-function context.
+   ANSI C explicitly permits this (the macro is not expanded).  */
+
+/* { dg-do compile } */
+/* { dg-options -Wtraditional } */
+
+enum { SIGN_EXTEND = 23 };
+
+#define SIGN_EXTEND(v) (((v) < 0) ? -1 : 0)
+
+int fun(void)
+{
+  return SIGN_EXTEND;	/* { dg-warning "in non-function context" } */
+}