Index: c-parser.c
===================================================================
--- c-parser.c	(revision 160889)
+++ c-parser.c	(working copy)
@@ -2706,7 +2706,7 @@ c_parser_parms_declarator (c_parser *par
 static struct c_arg_info *
 c_parser_parms_list_declarator (c_parser *parser, tree attrs)
 {
-  bool good_parm = false;
+  bool bad_parm = false;
   /* ??? Following the old parser, forward parameter declarations may
      use abstract declarators, and if no real parameter declarations
      follow the forward declarations then this is not diagnosed.  Also
@@ -2758,11 +2758,10 @@ c_parser_parms_list_declarator (c_parser
       /* Parse a parameter.  */
       struct c_parm *parm = c_parser_parameter_declaration (parser, attrs);
       attrs = NULL_TREE;
-      if (parm != NULL)
-	{
-	  good_parm = true;
-	  push_parm_decl (parm);
-	}
+      if (parm == NULL)
+	bad_parm = true;
+      else
+	push_parm_decl (parm);
       if (c_parser_next_token_is (parser, CPP_SEMICOLON))
 	{
 	  tree new_attrs;
@@ -2774,20 +2773,13 @@ c_parser_parms_list_declarator (c_parser
       if (c_parser_next_token_is (parser, CPP_CLOSE_PAREN))
 	{
 	  c_parser_consume_token (parser);
-	  if (good_parm)
-	    return get_parm_info (false);
-	  else
+	  if (bad_parm)
 	    {
-	      struct c_arg_info *ret
-		= XOBNEW (&parser_obstack, struct c_arg_info);
-	      ret->parms = 0;
-	      ret->tags = 0;
-	      ret->types = 0;
-	      ret->others = 0;
-	      ret->pending_sizes = 0;
-	      ret->had_vla_unspec = 0;
-	      return ret;
+	      get_pending_sizes ();
+	      return NULL;
 	    }
+	  else
+	    return get_parm_info (false);
 	}
       if (!c_parser_require (parser, CPP_COMMA,
 			     "expected %<;%>, %<,%> or %<)%>"))
@@ -2802,20 +2794,13 @@ c_parser_parms_list_declarator (c_parser
 	  if (c_parser_next_token_is (parser, CPP_CLOSE_PAREN))
 	    {
 	      c_parser_consume_token (parser);
-	      if (good_parm)
-		return get_parm_info (true);
-	      else
+	      if (bad_parm)
 		{
-		  struct c_arg_info *ret
-		    = XOBNEW (&parser_obstack, struct c_arg_info);
-		  ret->parms = 0;
-		  ret->tags = 0;
-		  ret->types = 0;
-		  ret->others = 0;
-		  ret->pending_sizes = 0;
-		  ret->had_vla_unspec = 0;
-		  return ret;
+		  get_pending_sizes ();
+		  return NULL;
 		}
+	      else
+		return get_parm_info (true);
 	    }
 	  else
 	    {
@@ -2841,10 +2826,22 @@ c_parser_parameter_declaration (c_parser
   bool dummy = false;
   if (!c_parser_next_token_starts_declspecs (parser))
     {
+      c_token *token = c_parser_peek_token (parser);
+      if (parser->error)
+	return NULL;
+      c_parser_set_source_position_from_token (token);
+      if (token->type == CPP_NAME
+	  && c_parser_peek_2nd_token (parser)->type != CPP_COMMA
+	  && c_parser_peek_2nd_token (parser)->type != CPP_CLOSE_PAREN)
+	{
+	  error ("unknown type name %qE", token->value);
+	  parser->error = true;
+	}
       /* ??? In some Objective-C cases '...' isn't applicable so there
 	 should be a different message.  */
-      c_parser_error (parser,
-		      "expected declaration specifiers or %<...%>");
+      else
+	c_parser_error (parser,
+			"expected declaration specifiers or %<...%>");
       c_parser_skip_to_end_of_parameter (parser);
       return NULL;
     }
Index: testsuite/gcc.dg/noncompile/pr44517.c
===================================================================
--- testsuite/gcc.dg/noncompile/pr44517.c	(revision 0)
+++ testsuite/gcc.dg/noncompile/pr44517.c	(revision 0)
@@ -0,0 +1,16 @@
+/* PR c/44517: Improve diagnostic for misspelled typename in function declaration. */
+int f1(int x, pid_t y, long z, in t) {  /* { dg-error "unknown type name 'pid_t'|unknown type name 'in'" } */
+  return x + y + z + t;
+}
+
+int f2(int x, lon y, long z, ...){ /* { dg-error "unknown type name 'lon'" } */
+  return;
+}
+
+void f3(int n, int a[n], pid_t x); /* { dg-error "unknown type name 'pid_t'" } */
+void f4() {}
+void f5(int a, *b); /* { dg-error "expected declaration specifiers or" } */
+void f6(int a, b);  /* { dg-error "expected declaration specifiers or" } */
+void f7(int a, goto b); /* { dg-error "expected declaration specifiers or" } */
+void f8(int a, in goto); /* { dg-error "unknown type name 'in'" } */
+void f9(int a, in 1); /* { dg-error "unknown type name 'in'" } */
Index: testsuite/gcc.dg/noncompile/990416-1.c
===================================================================
--- testsuite/gcc.dg/noncompile/990416-1.c	(revision 160889)
+++ testsuite/gcc.dg/noncompile/990416-1.c	(working copy)
@@ -2,11 +2,11 @@ extern void *memcpy (void *, const void 
 typedef int word_type;
    
 static void
-copy_reg (unsigned int reg, frame_state *udata,	/* { dg-error "parse|syntax|expected" } */
-	  frame_state *target_udata)	/* { dg-error "expected" } */
+copy_reg (unsigned int reg, frame_state *udata,	/* { dg-error "unknown type name" } */
+	  frame_state *target_udata)	/* { dg-error "unknown type name" } */
 {  
-  word_type *preg = get_reg_addr (reg, udata, 0);	/* { dg-error "undeclared|function|without a cast" } */
-  word_type *ptreg = get_reg_addr (reg, target_udata, 0); /* { dg-error "undeclared|without a cast" } */
+  word_type *preg = ge_reg_addr (reg, udata, 0);
+  word_type *ptreg = ge_reg_addr (reg, target_udata, 0);
    
   memcpy (ptreg, preg, __builtin_dwarf_reg_size (reg));
 }