http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52739
Bug #: 52739
Summary: [c++0x] Segfault because of nested lambda member
capture inside member template
Classification: Unclassified
Product: gcc
Version: 4.6.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: bruno-...@defraine.net
In the following specific combination of a class template, a member template,
and two nested lambdas, where the outer lambda captures `this' and the inner
lambda captures a member of `this', I can trigger a gcc segmentation fault.
test.cpp contains:
template<int n>
class Test {
int i;
public:
template<typename Func>
void foo(const Func& f);
};
template<int n> template<typename Func>
void Test<n>::foo(const Func& f) {
auto lam1 = [this,&f]() {
auto lam2 = [&i,&f]() {
f(i);
};
};
}
void bar(Test<1>& t) {
t.foo([](int i) { });
}
The compilation:
$ g++ -Wall -O2 -std=c++0x -c test.cpp
test.cpp: In lambda function:
test.cpp:12:17: 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 segmentation fault is always reproducible with gcc 4.6.2 on two platforms:
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/gcc-4.6.2/libexec/gcc/x86_64-unknown-linux-gnu/4.6.2/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --prefix=/opt/gcc-4.6.2
--enable-languages=c,c++,fortran --disable-multilib
Thread model: posix
gcc version 4.6.2 (GCC)
$ g++-fsf-4.6 -v
Using built-in specs.
COLLECT_GCC=g++-fsf-4.6
COLLECT_LTO_WRAPPER=/sw/lib/gcc4.6/libexec/gcc/x86_64-apple-darwin11.2.0/4.6.2/lto-wrapper
Target: x86_64-apple-darwin11.2.0
Configured with: ../gcc-4.6.2/configure --prefix=/sw --prefix=/sw/lib/gcc4.6
--mandir=/sw/share/man --infodir=/sw/lib/gcc4.6/info
--enable-languages=c,c++,fortran,lto,objc,obj-c++,java --with-gmp=/sw
--with-libiconv-prefix=/sw --with-ppl=/sw --with-cloog=/sw --with-mpc=/sw
--with-system-zlib --x-includes=/usr/X11R6/include --x-libraries=/usr/X11R6/lib
--program-suffix=-fsf-4.6 --enable-cloog-backend=isl
Thread model: posix
gcc version 4.6.2 (GCC)
I haven't tested this yet using gcc 4.6.3 nor gcc 4.7. My apologies if this has
been already fixed.
