[C++ PATCH, committed] Fix main return type warning (PR4494)

[Kriang Lerdsuwanakij]

Hi

This patch fixes a warning/error when the return type of main
is a typedef to int.  Committed as obvious to trunk.
Tested on i686-pc-linux-gnu.

--Kriang


2003-05-05  Kriang Lerdsuwanakij  <lerdsuwa@users.sourceforge.net>

	PR c++/4494
	* decl.c (start_function): Use same_type_p to check return type
	of main.

2003-05-05  Kriang Lerdsuwanakij  <lerdsuwa@users.sourceforge.net>

	PR c++/4494
	* g++.dg/warn/main.C: New test.


diff -cprN gcc-main-save/gcc/cp/decl.c gcc-main-new/gcc/cp/decl.c
*** gcc-main-save/gcc/cp/decl.c	Thu May  1 16:49:56 2003
--- gcc-main-new/gcc/cp/decl.c	Mon May  5 18:04:51 2003
*************** start_function (tree declspecs, tree dec
*** 13370,13377 ****
  	ctype = TYPE_METHOD_BASETYPE (fntype);
        else if (DECL_MAIN_P (decl1))
  	{
! 	  /* If this doesn't return integer_type, complain.  */
! 	  if (TREE_TYPE (TREE_TYPE (decl1)) != integer_type_node)
  	    {
  	      if (pedantic || warn_return_type)
  		pedwarn ("return type for `main' changed to `int'");
--- 13375,13383 ----
  	ctype = TYPE_METHOD_BASETYPE (fntype);
        else if (DECL_MAIN_P (decl1))
  	{
! 	  /* If this doesn't return integer_type, or a typedef to
! 	     integer_type, complain.  */
! 	  if (!same_type_p (TREE_TYPE (TREE_TYPE (decl1)), integer_type_node))
  	    {
  	      if (pedantic || warn_return_type)
  		pedwarn ("return type for `main' changed to `int'");
diff -cprN gcc-main-save/gcc/testsuite/g++.dg/warn/main.C gcc-main-new/gcc/testsuite/g++.dg/warn/main.C
*** gcc-main-save/gcc/testsuite/g++.dg/warn/main.C	Thu Jan  1 07:00:00 1970
--- gcc-main-new/gcc/testsuite/g++.dg/warn/main.C	Mon May  5 14:29:53 2003
***************
*** 0 ****
--- 1,11 ----
+ // { dg-do compile }
+ 
+ // Origin: Donald W. Gillies <dgillies@graviton.com>
+ 
+ // PR c++/4494: Incorrect diagnostics about return type of main.
+ 
+ typedef int int_t;
+ 
+ int_t main() {
+ 
+ }