[C PATCH] Warn about variadic main (PR c/60156)

[Marek Polacek]

I figured it might be a good idea to warn about variadic main decl
(well, not in freestanding environment where it's
implementation-defined).

Regtested/bootstrapped on x86_64-linux, ok for 5.0?

2014-02-12  Marek Polacek  <pola...@redhat.com>

        PR c/60156
c-family/
        * c-common.c (check_main_parameter_types): Warn about variadic main.
testsuite/
        * c-c++-common/pr60156.c: New test.

diff --git gcc/c-family/c-common.c gcc/c-family/c-common.c
index 5cf285b..bdf2852 100644
--- gcc/c-family/c-common.c
+++ gcc/c-family/c-common.c
@@ -2228,6 +2228,10 @@ check_main_parameter_types (tree decl)
   if (argct > 0 && (argct < 2 || argct > 3))
     pedwarn (input_location, OPT_Wmain,
             "%q+D takes only zero or two arguments", decl);
+
+  if (stdarg_p (TREE_TYPE (decl)))
+    pedwarn (input_location, OPT_Wmain,
+            "%q+D declared as variadic function", decl);
 }
 
 /* vector_targets_convertible_p is used for vector pointer types.  The
diff --git gcc/testsuite/c-c++-common/pr60156.c 
gcc/testsuite/c-c++-common/pr60156.c
index e69de29..1e8204c 100644
--- gcc/testsuite/c-c++-common/pr60156.c
+++ gcc/testsuite/c-c++-common/pr60156.c
@@ -0,0 +1,9 @@
+/* PR c/60156 */
+/* { dg-do compile } */
+/* { dg-options "-Wpedantic" } */
+
+int
+main (int argc, char *argv[], ...) /* { dg-warning "declared as variadic 
function" } */
+{
+  return 0;
+}

        Marek