Hi,
in this old bug Ian complained that the diagnostic we provide for:
typedef void v;
typedef v (*pf)(v);
is rather unfriendly, especially for people coming from C:
33101.C:2:17: error: ‘<anonymous>’ has incomplete type
33101.C:2:18: error: invalid use of ‘v’
thus Gaby (and Ian) suggested something along the lines of what I
propose below. Today I also noticed that some front-ends also deal
specially with cv-qualified void, thus added that case too, then just
generically 'void' I think it's good enough.
Thanks,
Paolo.
//////////////
/cp
2014-06-12 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/33101
* decl.c (grokparms): Improve error message about void parameters.
/testsuite
2014-06-12 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/33101
* g++.dg/other/void3.C: New.
* g++.dg/conversion/err-recover1.C: Update.
Index: cp/decl.c
===================================================================
--- cp/decl.c (revision 211574)
+++ cp/decl.c (working copy)
@@ -11161,10 +11161,25 @@ grokparms (tree parmlist, tree *parms)
{
if (same_type_p (type, void_type_node)
&& DECL_SELF_REFERENCE_P (type)
- && !DECL_NAME (decl) && !result && TREE_CHAIN (parm) ==
void_list_node)
+ && !DECL_NAME (decl) && !result
+ && TREE_CHAIN (parm) == void_list_node)
/* this is a parmlist of `(void)', which is ok. */
break;
- cxx_incomplete_type_error (decl, type);
+ else if (!cv_qualified_p (type)
+ && !DECL_SELF_REFERENCE_P (type)
+ && !DECL_NAME (decl) && !result
+ && TREE_CHAIN (parm) == void_list_node)
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "invalid use of typedef-name for type "
+ "%<void%> in parameter declaration");
+ else if (cv_qualified_p (type))
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "invalid use of cv-qualified type %<void%> "
+ "in parameter declaration");
+ else
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "invalid use of type %<void%> in parameter "
+ "declaration");
/* It's not a good idea to actually create parameters of
type `void'; other parts of the compiler assume that a
void type terminates the parameter list. */
Index: testsuite/g++.dg/conversion/err-recover1.C
===================================================================
--- testsuite/g++.dg/conversion/err-recover1.C (revision 211574)
+++ testsuite/g++.dg/conversion/err-recover1.C (working copy)
@@ -1,6 +1,6 @@
// PR c++/42219
-void foo(const void); // { dg-error "incomplete|const" }
+void foo(const void); // { dg-error "invalid use of cv-qualified" }
void bar()
{
Index: testsuite/g++.dg/other/void3.C
===================================================================
--- testsuite/g++.dg/other/void3.C (revision 0)
+++ testsuite/g++.dg/other/void3.C (working copy)
@@ -0,0 +1,4 @@
+// PR c++/33101
+
+typedef void v;
+typedef v (*pf)(v); // { dg-error "invalid use of typedef-name" }
