I am using an svn checkout of 4.5 trying to play with new c++0x features. I've tried debugging this myself, but gcc is huge and this is my first foray into it. I will list what I know.
My checkout information : $ svn info Path: . URL: svn://gcc.gnu.org/svn/gcc/trunk Repository Root: svn://gcc.gnu.org/svn/gcc Repository UUID: 138bc75d-0d04-0410-961f-82ee72b054a4 Revision: 155176 Node Kind: directory Schedule: normal Last Changed Author: rguenth Last Changed Rev: 155174 Last Changed Date: 2009-12-11 13:00:24 -0500 (Fri, 11 Dec 2009) Running my makefile accomplishes the following : LD_LIBRARY_PATH=/home/knome/local-gcc/lib /home/knome/local-gcc/bin/g++ -Wall --pedantic --std=c++0x main.cc Internal Compiler Error : attempt to lookup fileinfo for NULL. In static member function static boost::shared_ptr<monad::Monad<InnerType, RsType> > monad::Monad<InnerType, ChainType>::result(boost::shared_ptr<Y>) [with RsType = std::basic_string<char>, InnerType = monad::World, ChainType = monad::Undefined]: main.cc:49:65: instantiated from here cc1plus: internal compiler error: Segmentation fault Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. The error only occurs when using a lambda with copying variable capture. A lambda with no variable capture or reference capture does not trigger the segfault. A backtrace shows the source of the segfault seems to be a null tossed into the splay_tree_lookup function. I picked around some and found the null was coming from a LAMBDA_EXPR_LOCATION macro expansion. I put a watch on the input_location variable using gdb and the last three locations to update it before segfault are : Old value = 2634207 New value = 2633833 tsubst_decl (t=0xb7634400, args=<value optimized out>, complain=3) at ../.././gcc/cp/pt.c:8626 $113790 = 0x8ce5238 "main.cc" Hardware watchpoint 7: input_location Old value = 2633833 New value = 2634207 tsubst_decl (t=<value optimized out>, args=<value optimized out>, complain=<value optimized out>) at ../.././gcc/cp/pt.c:9381 $113791 = 0x8ce5238 "main.cc" Hardware watchpoint 7: input_location Old value = 2634207 New value = 0 build_lambda_object (lambda_expr=0xb7557aa8) at ../.././gcc/cp/semantics.c:5401 $113792 = 0x0 Internal Compiler Error : attempt to lookup fileinfo for NULL. Program received signal SIGSEGV, Segmentation fault. The relevant section in sematics.c being : if (processing_template_decl) return lambda_expr; /* Make sure any error messages refer to the lambda-introducer. */ saved_loc = input_location; > input_location = LAMBDA_EXPR_LOCATION (lambda_expr); for (node = LAMBDA_EXPR_CAPTURE_LIST (lambda_expr); node; node = TREE_CHAIN (node)) { tree field = TREE_PURPOSE (node); tree val = TREE_VALUE (node); I will continue trying to backtrack this to the source, but felt I should submit it as a bug so that someone with actual knowledge of gcc can have the chance to find it before I slowly work my way there. I've been looking through gcc/cp/parser.c trying to step through and see the bad assignment. I will continue with this sort of tracking as I can. -- Summary: NULL dereference in strcmp at libibery/splay-tree.c:148 (segfault) Product: gcc Version: 4.5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: knomenet at gmail dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42399
