c-decl.c (start_decl): Do not warn if variables is named as main and is a local variable.

2018-08-15  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>

c/
	* c-decl.c (start_decl): Do not warn if variables is named as main
	and is a local variable.

testsuite/
	* gcc.dg/wmain.c: New test.

From-SVN: r263562

gcc/c/ChangeLog

+2018-08-15  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
+	
+	* c-decl.c (start_decl): Do not warn if variables is named as main
+	and is a local variable.
+
 2018-08-15  Iain Sandoe  <iain@sandoe.co.uk>
 
 	PR c/19315

gcc/c/c-decl.c

@@ -4700,7 +4700,8 @@ start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs,
   if (expr)
     add_stmt (fold_convert (void_type_node, expr));
 
-  if (TREE_CODE (decl) != FUNCTION_DECL && MAIN_NAME_P (DECL_NAME (decl)))
+  if (TREE_CODE (decl) != FUNCTION_DECL && MAIN_NAME_P (DECL_NAME (decl))
+      && TREE_PUBLIC (decl))
     warning (OPT_Wmain, "%q+D is usually a function", decl);
 
   if (initialized)

gcc/testsuite/ChangeLog

+2018-08-15  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
+
+	* gcc.dg/wmain.c: New test.
+
 2018-08-15  Iain Sandoe  <iain@sandoe.co.uk>
 
 	PR c/19315

gcc/testsuite/gcc.dg/wmain.c

+/* { dg-do compile } */
+/* { dg-options "-Wall" } */
+
+int main; /* { dg-warning "'main' is usually a function" } */
+
+int foo()
+{
+  int main = 1; /* { dg-bogus "'main' is usually a function" } */
+  return main;
+}