[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

Jason Merrill  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 CC||jason at gcc dot gnu.org
 Resolution|--- |INVALID

--- Comment #7 from Jason Merrill  ---
lambda2 captures lambda1 by reference, and is then copied into func.  When
their block ends lambda1 no longer exists, so the reference in func is
dangling, and so invoking it has undefined behavior.

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

Paolo Carlini  changed:

   What|Removed |Added

   Priority|P3  |P2
 CC|gcc at norgg dot org   |

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

Martin Sebor  changed:

   What|Removed |Added

 Status|WAITING |NEW
  Known to fail||5.3.1, 6.3.0, 7.0

--- Comment #6 from Martin Sebor  ---
Thank you.  I still can't reproduce the problem with -O0 but I do see a SIGSEGV
on x86_64 when I compile the test case with -O1 or higher, with all of GCC 5.x,
6.x, and 7.0.  Thus confirmed.

$ /ssd/build/gcc-6-branch/gcc/xg++ -B /ssd/build/gcc-6-branch/gcc -nostdinc++
-I
/ssd/build/gcc-6-branch/x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu
-I /ssd/build/gcc-6-branch/x86_64-pc-linux-gnu/libstdc++-v3/include -I
/src/gcc/6-branch/libstdc++-v3/libsupc++ -I
/src/gcc/6-branch/libstdc++-v3/include/backward -I
/src/gcc/6-branch/libstdc++-v3/testsuite/util -L
/ssd/build/gcc-6-branch/x86_64-pc-linux-gnu/libstdc++-v3/src/.libs -std=gnu++1z
-g -O1 t.C && gdb -batch -q -ex r -ex bt a.out 

Program received signal SIGSEGV, Segmentation fault.
0x0040064c in ::operator() (__closure=0x7fffde68) at
t.C:9
9   auto lambda1 = [&]{ (*j)++; };
#0  0x0040064c in ::operator() (__closure=0x7fffde68) at
t.C:9
#1  ::operator() (__closure=0x7fffdea0,
__closure@entry=0x7fffde30) at t.C:10
#2  std::_Function_handler >::_M_invoke(const
std::_Any_data &) (__functor=...) at
/ssd/build/gcc-6-branch/x86_64-pc-linux-gnu/libstdc++-v3/include/functional:1731
#3  0x004006bf in std::function::operator()() const
(this=0x7fffdea0) at
/ssd/build/gcc-6-branch/x86_64-pc-linux-gnu/libstdc++-v3/include/functional:2127
#4  main () at t.C:16

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[gcc at norgg dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

--- Comment #5 from Norgg  ---
Created attachment 40994
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40994=edit
gcc -v output for gcc 6.2.0

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[gcc at norgg dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

Norgg  changed:

   What|Removed |Added

 CC||gcc at norgg dot org

--- Comment #4 from Norgg  ---
Created attachment 40993
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40993=edit
gcc -v output for gcc 5.4.0

(In reply to Martin Sebor from comment #3)
> I also cannot reproduce it with 7.0 on powepc64le or with 5.x on x86_64. 
> Can you please list the processor architectures you see this problem on? 
> (Providing the output of gcc -v should help.)

I can still reproduce this on my x86_64 Ubuntu system, in both g++ 5.4.1 and
6.2.0, gcc -v output from each attached.

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

Martin Sebor  changed:

   What|Removed |Added

 Status|UNCONFIRMED |WAITING
   Last reconfirmed||2017-03-16
 CC||msebor at gcc dot gnu.org
 Ever confirmed|0   |1

--- Comment #3 from Martin Sebor  ---
I also cannot reproduce it with 7.0 on powepc64le or with 5.x on x86_64.  Can
you please list the processor architectures you see this problem on? 
(Providing the output of gcc -v should help.)

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

--- Comment #2 from Andrew Pinski  ---
Can't reproduce this on aarch64-linux-gnu with GCC 6.1.0.

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

Andrew Pinski  changed:

   What|Removed |Added

   Keywords||wrong-code
   Severity|major   |normal

[Bug c++/70515] Nested lambdas causing invalid captured pointers on some platforms

[gcc at norgg dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70515

--- Comment #1 from Norgg  ---
Created attachment 38164
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38164=edit
Preprocessed file