The following invalid testcase triggers a broken diagnostic since GCC 3.3.1:
=================================== struct A {}; void foo() { ++__builtin_va_arg(0, A); } =================================== bug.cc:5: error: no match for 'operator++' in '++#'va_arg_expr' not supported by dump_expr#<expression error>' -- Summary: [4.1/4.2/4.3 regression] Broken diagnostic: 'va_arg_expr' not supported by dump_expr Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: diagnostic, monitored Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: reichelt at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33462