Compiling the following testcase with "g++ -fmudflap" yields an ICE since GCC 4.1.0 (i.e. this is a regression):
================= struct A; A a; ================= bug.cc:2: error: aggregate 'A a' has incomplete type and cannot be defined bug.cc:2: internal compiler error: tree check: expected class 'type', have 'exceptional' (error_mark) in mudflap_finish_file, at tree-mudflap.c:1265 Please submit a full bug report, [etc.] Testing a patch. -- Summary: [4.1/4.2 regression] ICE on incomplete struct with - fmudflap 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=26789