cp-tree.h (MAIN_NAME_P): New macro.

	* cp-tree.h (MAIN_NAME_P): New macro.
	(DECL_MAIN_P): Likwise.
	* decl.c (pushdecl): Avoid crashing on redefinitions of `main'.
	(grokfndecl): Use the new macros.
	(grokdeclarator): Likewise.
	(start_function): Likewise.
	(store_parm_decls): Likewise.
	(finsh_function): Likewise.
	* friend.c (do_friend): Likewise.
	* typeck.c (build_function_call_real): Likewise.
	(build_unary_op): Likewise.

From-SVN: r19907

gcc/cp/ChangeLog

+1998-05-20  Mark Mitchell  <mmitchell@usa.net>
+
+	* cp-tree.h (MAIN_NAME_P): New macro.
+	(DECL_MAIN_P): Likwise.
+	* decl.c (pushdecl): Avoid crashing on redefinitions of `main'.
+	(grokfndecl): Use the new macros.
+	(grokdeclarator): Likewise.
+	(start_function): Likewise.
+	(store_parm_decls): Likewise.
+	(finsh_function): Likewise.
+	* friend.c (do_friend): Likewise.
+	* typeck.c (build_function_call_real): Likewise.
+	(build_unary_op): Likewise.
+
 Wed May 20 02:16:01 1998  Jason Merrill  <jason@yorick.cygnus.com>
 
 	* decl2.c (start_objects, finish_objects, do_dtors,

gcc/cp/cp-tree.h

@@ -1918,6 +1918,21 @@ extern int current_function_parms_stored;
 #define ANON_PARMNAME_P(ID_NODE) (IDENTIFIER_POINTER (ID_NODE)[0] == '_' \
 				  && IDENTIFIER_POINTER (ID_NODE)[1] <= '9')
 #endif /* !defined(NO_DOLLAR_IN_LABEL) || !defined(NO_DOT_IN_LABEL) */
+
+/* Returns non-zero iff ID_NODE is an IDENTIFIER_NODE whose name is
+   `main'.  */
+#define MAIN_NAME_P(ID_NODE) \
+   (strcmp (IDENTIFIER_POINTER (ID_NODE), "main") == 0)
+
+/* Returns non-zero iff NODE is a declaration for the global function
+   `main'.  */
+#define DECL_MAIN_P(NODE)				\
+   (TREE_CODE (NODE) == FUNCTION_DECL			\
+    && (DECL_CONTEXT (NODE) == global_namespace 	\
+	|| DECL_CONTEXT (NODE) == NULL_TREE)		\
+    && DECL_NAME (NODE) != NULL_TREE			\
+    && MAIN_NAME_P (DECL_NAME (NODE)))
+
 
 /* Define the sets of attributes that member functions and baseclasses
    can have.  These are sensible combinations of {public,private,protected}

gcc/cp/decl.c

@@ -3345,6 +3345,20 @@ pushdecl (x)
 
 	      return t;
 	    }
+	  else if (DECL_MAIN_P (x))
+	    {
+	      /* A redeclaration of main, but not a duplicate of the
+		 previous one. 
+
+		 [basic.start.main]
+
+	         This function shall not be overloaded.  */
+	      cp_error_at ("invalid redeclaration of `%D'", t);
+	      cp_error ("as `%D'", x);
+	      /* We don't try to push this declaration since that
+		 causes a crash.  */
+	      return x;
+	    }
 	}
 
       if (TREE_CODE (x) == FUNCTION_DECL && ! DECL_FUNCTION_MEMBER_P (x))
@@ -7545,7 +7559,7 @@ grokfndecl (ctype, type, declarator, orig_declarator, virtualp, flags, quals,
   if (ctype)
     DECL_CLASS_CONTEXT (decl) = ctype;
 
-  if (ctype == NULL_TREE && ! strcmp (IDENTIFIER_POINTER (declarator), "main"))
+  if (ctype == NULL_TREE && MAIN_NAME_P (declarator))
     {
       if (inlinep)
 	error ("cannot declare `main' to be inline");
@@ -10077,9 +10091,7 @@ grokdeclarator (declarator, declspecs, decl_context, initialized, attrlist)
 
 	    if (current_lang_name == lang_name_cplusplus
 		&& ! processing_template_decl
-		&& ! (IDENTIFIER_LENGTH (original_name) == 4
-		      && IDENTIFIER_POINTER (original_name)[0] == 'm'
-		      && strcmp (IDENTIFIER_POINTER (original_name), "main") == 0)
+		&& ! MAIN_NAME_P (original_name)
 		&& ! (IDENTIFIER_LENGTH (original_name) > 10
 		      && IDENTIFIER_POINTER (original_name)[0] == '_'
 		      && IDENTIFIER_POINTER (original_name)[1] == '_'
@@ -11724,9 +11736,7 @@ start_function (declspecs, declarator, attrs, pre_parsed_p)
 
       if (TREE_CODE (fntype) == METHOD_TYPE)
 	ctype = TYPE_METHOD_BASETYPE (fntype);
-      else if (IDENTIFIER_LENGTH (DECL_NAME (decl1)) == 4
-	       && ! strcmp (IDENTIFIER_POINTER (DECL_NAME (decl1)), "main")
-	       && DECL_CONTEXT (decl1) == NULL_TREE)
+      else if (DECL_MAIN_P (decl1))
 	{
 	  /* If this doesn't return integer_type, complain.  */
 	  if (TREE_TYPE (TREE_TYPE (decl1)) != integer_type_node)
@@ -12121,10 +12131,8 @@ store_parm_decls ()
 
   /* If this function is `main', emit a call to `__main'
      to run global initializers, etc.  */
-  if (DECL_NAME (fndecl)
-      && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 4
-      && strcmp (IDENTIFIER_POINTER (DECL_NAME (fndecl)), "main") == 0
-      && DECL_CONTEXT (fndecl) == global_namespace)
+  if (DECL_MAIN_P (fndecl))
+    expand_main_function ();
     {
       expand_main_function ();
     }
@@ -12576,9 +12584,7 @@ finish_function (lineno, call_poplevel, nested)
 	  current_function_assigns_this = 0;
 	  current_function_just_assigned_this = 0;
 	}
-      else if (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 4
-	       && ! strcmp (IDENTIFIER_POINTER (DECL_NAME (fndecl)), "main")
-	       && DECL_CONTEXT (fndecl) == global_namespace)
+      else if (DECL_MAIN_P (fndecl))
 	{
 	  /* Make it so that `main' always returns 0 by default.  */
 #ifdef VMS

gcc/cp/friend.c

@@ -364,9 +364,7 @@ do_friend (ctype, declarator, decl, parmdecls, flags, quals, funcdef_flag)
 	}
     }
   else if (TREE_CODE (decl) == FUNCTION_DECL
-	   && ((IDENTIFIER_LENGTH (declarator) == 4
-		&& IDENTIFIER_POINTER (declarator)[0] == 'm'
-		&& ! strcmp (IDENTIFIER_POINTER (declarator), "main"))
+	   && (MAIN_NAME_P (declarator)
 	       || (IDENTIFIER_LENGTH (declarator) > 10
 		   && IDENTIFIER_POINTER (declarator)[0] == '_'
 		   && IDENTIFIER_POINTER (declarator)[1] == '_'

gcc/cp/typeck.c

@@ -2744,14 +2744,8 @@ build_function_call_real (function, params, require_complete, flags)
       fndecl = function;
 
       /* Convert anything with function type to a pointer-to-function.  */
-      if (pedantic
-	  && name
-	  && IDENTIFIER_LENGTH (name) == 4
-	  && ! strcmp (IDENTIFIER_POINTER (name), "main")
-	  && DECL_CONTEXT (function) == global_namespace)
-	{
-	  pedwarn ("ANSI C++ forbids calling `main' from within program");
-	}
+      if (pedantic && DECL_MAIN_P (function))
+	pedwarn ("ANSI C++ forbids calling `main' from within program");
 
       /* Differs from default_conversion by not setting TREE_ADDRESSABLE
 	 (because calling an inline function does not mean the function
@@ -4509,13 +4503,7 @@ build_unary_op (code, xarg, noconvert)
 	  TREE_CONSTANT (arg) = TREE_CONSTANT (TREE_OPERAND (arg, 0));
 	  return arg;
 	}
-      else if (pedantic
-	       && TREE_CODE (arg) == FUNCTION_DECL
-	       && DECL_NAME (arg)
-	       && DECL_CONTEXT (arg) == global_namespace
-	       && IDENTIFIER_LENGTH (DECL_NAME (arg)) == 4
-	       && IDENTIFIER_POINTER (DECL_NAME (arg))[0] == 'm'
-	       && ! strcmp (IDENTIFIER_POINTER (DECL_NAME (arg)), "main"))
+      else if (pedantic && DECL_MAIN_P (arg))
 	/* ARM $3.4 */
 	pedwarn ("taking address of function `main'");