The following code snippet triggers an ICE on mainline when compiled with "g++ -O -g":
=================== double foo() { union { int i; double d; }; i = 0; return d; } =================== bug.cc: In function 'double foo()': bug.cc:11: internal compiler error: in mem_loc_descriptor, at dwarf2out.c:9010 Please submit a full bug report, [etc.] -- Summary: [4.3 regression] ICE with anonymous union and Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: ice-on-valid-code, monitored Severity: normal Priority: P3 Component: debug 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=30898