I'm writing a tutorial on a HelloWorld compiler front-end for GCC (http://svn.gna.org/viewcvs/gsc/branches/hello-world/doc/hello.xml) and noticed that a function with statements but no DECL_SOURCE_FILE set, seg-faults on cgraph_finalize_function(), because it calls gimple-low.c:lower_function_body(), which in turn does:
SET_EXPR_LOCATION (x, cfun->function_end_locus); however, if cfun->function_end_locus is empty ({NULL, 0}), it will call tree.c:annotate_with_file_line() with file=NULL, and it will fail on this "if": if (last_annotated_node && last_annotated_node->line == line && (last_annotated_node->file == file || !strcmp (last_annotated_node->file, file))) because strcmp (last_annotated_node->file, file), with file=NULL will seg-fault. The attached patch checks if file is NULL before using strcmp. The program that fails build is: http://svn.gna.org/viewcvs/gsc/branches/hello-world/compiler/hello1.c?rev=551 -- Summary: GCC segfault's on strcmp in tree.c:annotate_with_file_line Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: barbieri at gmail dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24932