The following invalid code snippet triggers an ICE since at least GCC 2.95.3:
========================================= namespace N { struct A {}; typedef void foo(A); } template<typename T> void bar() { T t; foo(t); } template void bar<N::A>(); ========================================= gimplification failed: foo <type_decl 0x2aaaaaf1fb60 foo type <function_type 0x2aaaaaf7c580 foo type <void_type 0x2aaaaae140b0 void type_6 VOID align 8 symtab 0 alias set -1 pointer_to_this <pointer_type 0x2aaaaae14160>> QI size <integer_cst 0x2aaaaadef7b0 constant invariant 8> unit size <integer_cst 0x2aaaaadef7e0 constant invariant 1> align 8 symtab 0 alias set -1 arg-types <tree_list 0x2aaaaaf222d0 value <record_type 0x2aaaaaf7c370 A> chain <tree_list 0x2aaaaae0dcf0 value <void_type 0x2aaaaae140b0 void >>> pointer_to_this <pointer_type 0x2aaaaaf7cc60>> used VOID file bug.cc line 4 align 1 context <namespace_decl 0x2aaaaaf1f820 N> result <function_type 0x2aaaaaf7c4d0 type <void_type 0x2aaaaae140b0 void> QI size <integer_cst 0x2aaaaadef7b0 8> unit size <integer_cst 0x2aaaaade f7e0 1> align 8 symtab 0 alias set -1 arg-types <tree_list 0x2aaaaaf222d0>>> bug.cc: In function 'void bar() [with T = N::A]': bug.cc:9: instantiated from here bug.cc:7: internal compiler error: gimplification failed Please submit a full bug report, [etc.] -- Summary: ICE trying to gimplify invalid code Product: gcc Version: 4.2.0 Status: UNCONFIRMED Keywords: ice-on-invalid-code, 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=28348