c: Add new -Wdeclaration-missing-parameter-type permerror

This used to be a warning, enabled by default, without its own option.

A subsequent change could improve diagnostics and provide spelling
hints for declarations like “void function (int32t);”.

gcc/c-family/

	* c.opt (Wdeclaration-missing-parameter-type): New.

gcc/c/ChangeLog:

	PR other/44209
	* c-decl.cc (grokparms): Issue permerror for
	OPT_Wdeclaration_missing_parameter_type instead of a pedwarn.

gcc/ChangeLog:

	* doc/invoke.texi (Warning Options): Document
	-Wdeclaration-missing-parameter-type.

gcc/testsuite/ChangeLog:

	* gcc.dg/permerror-default.c (missing_parameter_type):
	Expect error.
	* gcc.dg/permerror-fpermissive.c (missing_parameter_type):
	Expect -Wdeclaration-missing-parameter-type warning.
	* gcc.dg/permerror-gnu89-nopermissive.c (missing_parameter_type):
	Expect -Wdeclaration-missing-parameter-type error.
	* gcc.dg/permerror-gnu89-pedantic.c (missing_parameter_type):
	Likewise.
	* gcc.dg/permerror-gnu89.c (missing_parameter_type):
	Expect -Wdeclaration-missing-parameter-type warning.
	* gcc.dg/permerror-noerror.c: Add
	-Wno-error=declaration-missing-parameter-type to build flags.
	(missing_parameter_type): Expect
	-Wdeclaration-missing-parameter-type warning.
	* gcc.dg/permerror-nowarning.c: Build with
	-Wno-declaration-missing-parameter-type.  Remove previously
	expected warning.
	* gcc.dg/permerror-fpermissive-nowarning.c: Likewise.
	* gcc.dg/permerror-pedantic.c (missing_parameter_type):
	Expect -Wdeclaration-missing-parameter-type error.
	* gcc.dg/permerror-system.c (missing_parameter_type):
	Likewise.

1 files changed, 4 insertions, 2 deletions

diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 8123924..d388e12 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -8343,8 +8343,10 @@ grokparms (struct c_arg_info *arg_info, bool funcdef_flag)
     {
       if (!funcdef_flag)
 	{
-	  pedwarn (input_location, 0, "parameter names (without types) in "
-		   "function declaration");
+	  permerror_opt (input_location,
+			 OPT_Wdeclaration_missing_parameter_type,
+			 "parameter names (without types) in "
+			 "function declaration");
 	  arg_info->parms = NULL_TREE;
 	}
       else