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::result(boost::shared_ptr)
[with RsType = std::basic_string, 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=, 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=, args=,
complain=) 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
