[Bug c++/65727] New: Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[Bug c++/65727] New: Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[mmccurry at gatech dot edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

            Bug ID: 65727
           Summary: Segfault With Decltype In Lambda Expression Used To
                    Initialize Static Class Member
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mmccurry at gatech dot edu

Created attachment 35284
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35284&action=edit
Minimal Test Case

Using version 4.8.2 of g++ in an x86 environment, a segfault is possible with
the attached code

The build of this compiler was performed via the following slackware build
script
ftp://ftp.slackware.com/pub/slackware/slackware-14.1/source/d/gcc/gcc.SlackBuild

When the file is built, the following output is produced:

---------------------------------------------------
$ g++ -std=c++11 gcc-4.8.2-bug.cpp 
gcc-4.8.2-bug.cpp: In lambda function:
gcc-4.8.2-bug.cpp:22:55: internal compiler error: Segmentation fault
 type_b type_e::b = {{[](){decltype(function_c(type_e::d))::dummy();}}};
                                                       ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
---------------------------------------------------

It looks like there are some similar bugs which have been fixed in the past,
but none of them seem to have the same requirements as this segfault.
Additionally the codebase which produced this issue has been reported to
produce segfaults in version 4.9.1 though it is unknown if this minimal test
case produces the segfault in the more recent versions.

[Bug c++/65727] [4.8/4.9/5 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-04-10
                 CC|                            |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |4.8.5
            Summary|Segfault With Decltype In   |[4.8/4.9/5 Regression]
                   |Lambda Expression Used To   |Segfault With Decltype In
                   |Initialize Static Class     |Lambda Expression Used To
                   |Member                      |Initialize Static Class
                   |                            |Member
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed with 4.8/4.9/5.  4.7 was ok.

[Bug c++/65727] [4.8/4.9/5 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
           Priority|P3                          |P2

[Bug c++/65727] [4.8/4.9/5 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |jason at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org

[Bug c++/65727] [4.8/4.9/5/6 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Wed Apr 15 21:17:03 2015
New Revision: 222132

URL: https://gcc.gnu.org/viewcvs?rev=222132&root=gcc&view=rev
Log:
    PR c++/65727
    * lambda.c (lambda_expr_this_capture): In unevaluated context go
    through the normal loop, just don't capture.
    (maybe_resolve_dummy): Handle null return.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-decltype2.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/lambda.c

[Bug c++/65727] [4.8/4.9/5/6 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Wed Apr 22 20:53:07 2015
New Revision: 222340

URL: https://gcc.gnu.org/viewcvs?rev=222340&root=gcc&view=rev
Log:
    PR c++/65727
    * lambda.c (maybe_resolve_dummy): Handle null return.

Added:
    branches/gcc-5-branch/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-decltype2.C
Modified:
    branches/gcc-5-branch/gcc/cp/ChangeLog
    branches/gcc-5-branch/gcc/cp/lambda.c

[Bug c++/65727] [4.8/4.9/5/6 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Thu Apr 23 13:20:14 2015
New Revision: 222364

URL: https://gcc.gnu.org/viewcvs?rev=222364&root=gcc&view=rev
Log:
    PR c++/65727
    * semantics.c (maybe_resolve_dummy): Handle null return.

Added:
   
branches/gcc-4_8-branch/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-decltype2.C
Modified:
    branches/gcc-4_8-branch/gcc/cp/ChangeLog
    branches/gcc-4_8-branch/gcc/cp/semantics.c
    branches/gcc-4_8-branch/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-ice3.C

[Bug c++/65727] [4.8/4.9/5/6 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Thu Apr 23 13:21:22 2015
New Revision: 222368

URL: https://gcc.gnu.org/viewcvs?rev=222368&root=gcc&view=rev
Log:
    PR c++/65727
    * lambda.c (maybe_resolve_dummy): Handle null return.

Added:
   
branches/gcc-4_9-branch/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-decltype2.C
Modified:
    branches/gcc-4_9-branch/gcc/cp/ChangeLog
    branches/gcc-4_9-branch/gcc/cp/lambda.c
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-ice3.C

[Bug c++/65727] [4.8/4.9/5/6 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65727

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for 4.8.5/4.9.3/5.2/6.