(C++) patch to catch implicit int

[Jason Merrill]

We have been lax about diagnosing implicit int on functions, even with
-pedantic.  This is clear given the number of testcases I had to fix after
making this change: about 400.  Fortunately s/^main/int main/ did most of
the work for me.

This patch still allows implicit int on the definition of main, unless
-pedantic or -Wreturn-type are specified.

1998-11-22  Jason Merrill  <jason@yorick.cygnus.com>

	* decl.c: Lose warn_about_return_type.
	(grokdeclarator): Always complain about implicit int, except for
	`main () { ... }'.

Index: decl.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/cp/decl.c,v
retrieving revision 1.269
diff -c -p -r1.269 decl.c
*** decl.c	1998/11/22 21:34:24	1.269
--- decl.c	1998/11/23 07:17:02
*************** int current_function_returns_null;
*** 509,519 ****
  
  tree current_function_return_value;
  
- /* Set to nonzero by `grokdeclarator' for a function
-    whose return type is defaulted, if warnings for this are desired.  */
- 
- static int warn_about_return_type;
- 
  /* Nonzero means give `double' the same size as `float'.  */
  
  extern int flag_short_double;
--- 509,514 ----
*************** grokdeclarator (declarator, declspecs, d
*** 9117,9140 ****
  	}
        else
  	{
! 	  if (funcdef_flag)
! 	    {
! 	      if (warn_return_type
! 		  && return_type == return_normal)
! 		/* Save warning until we know what is really going on.  */
! 		warn_about_return_type = 1;
! 	    }
! 	  else if (RIDBIT_SETP (RID_TYPEDEF, specbits))
! 	    pedwarn ("ANSI C++ forbids typedef which does not specify a type");
! 	  else if (innermost_code != CALL_EXPR || pedantic
! 		   || (warn_return_type && return_type == return_normal))
! 	    {
! 	      if (innermost_code == CALL_EXPR)
! 		cp_pedwarn ("return-type of `%D' defaults to `int'", dname);
! 	      else
! 		cp_pedwarn ("ANSI C++ forbids declaration `%D' with no type",
! 			    dname);
! 	    }
  	  type = integer_type_node;
  	}
      }
--- 9112,9127 ----
  	}
        else
  	{
! 	  if (! pedantic && ! warn_return_type
! 	      && funcdef_flag
! 	      && MAIN_NAME_P (dname)
! 	      && ctype == NULL_TREE
! 	      && in_namespace == NULL_TREE
! 	      && current_namespace == global_namespace)
! 	    /* Let `main () { }' slide, since it's so common.  */;
! 	  else
! 	    cp_pedwarn ("ANSI C++ forbids declaration `%D' with no type",
! 			dname);
  	  type = integer_type_node;
  	}
      }
*************** start_function (declspecs, declarator, a
*** 12482,12488 ****
    /* Assume, until we see it does.  */
    current_function_returns_value = 0;
    current_function_returns_null = 0;
-   warn_about_return_type = 0;
    named_labels = 0;
    shadowed_labels = 0;
    current_function_assigns_this = 0;
--- 12469,12474 ----
*************** start_function (declspecs, declarator, a
*** 12597,12603 ****
  		pedwarn ("return type for `main' changed to `int'");
  	      TREE_TYPE (decl1) = fntype = default_function_type;
  	    }
- 	  warn_about_return_type = 0;
  	}
      }
  
--- 12583,12588 ----
*************** start_function (declspecs, declarator, a
*** 12648,12656 ****
  	abstract_virtuals_error (decl1, TREE_TYPE (fntype));
      }
  
-   if (warn_about_return_type)
-     pedwarn ("return-type defaults to `int'");
- 
    /* Effective C++ rule 15.  See also c_expand_return.  */
    if (warn_ecpp
        && DECL_NAME (decl1) == ansi_opname[(int) MODIFY_EXPR]
--- 12633,12638 ----
*************** struct cp_function
*** 14106,14112 ****
  {
    int returns_value;
    int returns_null;
-   int warn_about_return_type;
    int assigns_this;
    int just_assigned_this;
    int parms_stored;
--- 14088,14093 ----
*************** push_cp_function_context (context)
*** 14153,14159 ****
    p->shadowed_labels = shadowed_labels;
    p->returns_value = current_function_returns_value;
    p->returns_null = current_function_returns_null;
-   p->warn_about_return_type = warn_about_return_type;
    p->binding_level = current_binding_level;
    p->ctor_label = ctor_label;
    p->dtor_label = dtor_label;
--- 14134,14139 ----
*************** pop_cp_function_context (context)
*** 14196,14202 ****
    shadowed_labels = p->shadowed_labels;
    current_function_returns_value = p->returns_value;
    current_function_returns_null = p->returns_null;
-   warn_about_return_type = p->warn_about_return_type;
    current_binding_level = p->binding_level;
    ctor_label = p->ctor_label;
    dtor_label = p->dtor_label;
--- 14176,14181 ----