Hi,
I have just regtested on x86_64-linux the below patchlet for a simple
accepts-invalid, exploiting type_uses_auto, as suggested by Jason.
We want to do that only when processing a template, because otherwise we
get a duplicate diagnostic, see, eg, auto9.C; also, not returning
error_mark_node unconditionally, means a better diagnostic, without
redundant "array bound is not an integer constant before...". As for the
error message itself, I'm just emitting what we otherwise emit outside
templates...
Ok?
Thanks,
Paolo.
///////////////////
/cp
2011-05-26 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/42056
* typeck2.c (build_functional_cast): When processing_template_decl,
check for invalid uses of 'auto'.
/testsuite
2011-05-26 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/42056
* testsuite/g++.dg/cpp0x/auto25.C: New.
* testsuite/g++.dg/cpp0x/auto26.C: Likewise.
Index: testsuite/g++.dg/cpp0x/auto25.C
===================================================================
--- testsuite/g++.dg/cpp0x/auto25.C (revision 0)
+++ testsuite/g++.dg/cpp0x/auto25.C (revision 0)
@@ -0,0 +1,7 @@
+// PR c++/42056
+// { dg-options -std=c++0x }
+
+template<int> struct A
+{
+ int a[auto(1)]; // { dg-error "invalid use of" }
+};
Index: testsuite/g++.dg/cpp0x/auto26.C
===================================================================
--- testsuite/g++.dg/cpp0x/auto26.C (revision 0)
+++ testsuite/g++.dg/cpp0x/auto26.C (revision 0)
@@ -0,0 +1,7 @@
+// PR c++/42056
+// { dg-options -std=c++0x }
+
+template<int> void foo()
+{
+ int a[auto(1)]; // { dg-error "invalid use of" }
+}
Index: cp/typeck2.c
===================================================================
--- cp/typeck2.c (revision 174301)
+++ cp/typeck2.c (working copy)
@@ -1603,6 +1603,14 @@ build_functional_cast (tree exp, tree parms, tsubs
{
tree t;
+ if (type_uses_auto (type))
+ {
+ if (complain & tf_error)
+ error ("invalid use of %<auto%>");
+ else
+ return error_mark_node;
+ }
+
/* Diagnose this even in a template. We could also try harder
to give all the usual errors when the type and args are
non-dependent... */
