[Bug pch/112319] New: segfault with pch and #pragma GCC diagnostic

[Bug pch/112319] New: segfault with pch and #pragma GCC diagnostic

[krebbel at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112319

            Bug ID: 112319
           Summary: segfault with pch and #pragma GCC diagnostic
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: pch
          Assignee: unassigned at gcc dot gnu.org
          Reporter: krebbel at gcc dot gnu.org
  Target Milestone: ---

touch s.h
touch u.h

main.cpp:
#include "s.h"
#include "u.h"

g++ s.h
g++ -c main.cpp --save-temps
In file included from main.cpp:2:
u.h:1:9: internal compiler error: Segmentation fault
    1 | #pragma GCC diagnostic
      |         ^~~
0x1764fbf crash_signal
        /home/andreas/build/../gcc/gcc/toplev.cc:314
0x10201cd maybe_read_tokens_for_pragma_lex
        /home/andreas/build/../gcc/gcc/cp/parser.cc:49713
0x10201cd pragma_lex(tree_node**, unsigned int*)
        /home/andreas/build/../gcc/gcc/cp/parser.cc:49735
0x11a962c pragma_diagnostic_lex
        /home/andreas/build/../gcc/gcc/c-family/c-pragma.cc:851
0x11a9d78 handle_pragma_diagnostic_impl<true, true>
        /home/andreas/build/../gcc/gcc/c-family/c-pragma.cc:879
0x11a9d78 handle_pragma_diagnostic_early_pp
        /home/andreas/build/../gcc/gcc/c-family/c-pragma.cc:1039
0x11abdbd c_pp_invoke_early_pragma_handler(unsigned int)
        /home/andreas/build/../gcc/gcc/c-family/c-pragma.cc:1769
0x11a8180 token_streamer::stream(cpp_reader*, cpp_token const*, unsigned int)
        /home/andreas/build/../gcc/gcc/c-family/c-ppoutput.cc:293
0x11a8461 scan_translation_unit
        /home/andreas/build/../gcc/gcc/c-family/c-ppoutput.cc:351
0x11a8461 preprocess_file(cpp_reader*)
        /home/andreas/build/../gcc/gcc/c-family/c-ppoutput.cc:106
0x11a693d c_common_init()
        /home/andreas/build/../gcc/gcc/c-family/c-opts.cc:1236
0xfa35be cxx_init()
        /home/andreas/build/../gcc/gcc/cp/lex.cc:338
0xe94153 lang_dependent_init
        /home/andreas/build/../gcc/gcc/toplev.cc:1816
0xe94153 do_compile
        /home/andreas/build/../gcc/gcc/toplev.cc:2111
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

Can be reproduced on x86 and s390x since:

e664ea960a200aac88ffc3c7fb9fe55ea4df2011 is the first bad commit                
commit e664ea960a200aac88ffc3c7fb9fe55ea4df2011                                 
Author: Lewis Hyatt <lhyatt@gmail.com>                                          
Date:   Fri Jun 30 18:23:24 2023 -0400                                          

    c-family: Implement pragma_lex () for preprocess-only mode

[Bug pch/112319] segfault with pch and #pragma GCC diagnostic

[lhyatt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112319

Lewis Hyatt <lhyatt at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |lhyatt at gcc dot gnu.org
   Last reconfirmed|                            |2023-10-31
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Lewis Hyatt <lhyatt at gcc dot gnu.org> ---
Thanks, I see it (with u.h containing a #pragma GCC diagnostic as its first
line). Will sort that out.

[Bug pch/112319] [14 Regression] segfault with pch and #pragma GCC diagnostic

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112319

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0
            Summary|segfault with pch and       |[14 Regression] segfault
                   |#pragma GCC diagnostic      |with pch and #pragma GCC
                   |                            |diagnostic
           Keywords|                            |ice-on-valid-code

[Bug pch/112319] [14 Regression] segfault with pch and #pragma GCC diagnostic

[lhyatt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112319

--- Comment #2 from Lewis Hyatt <lhyatt at gcc dot gnu.org> ---
Patch sent for review:
https://gcc.gnu.org/pipermail/gcc-patches/2023-November/634931.html

[Bug pch/112319] [14 Regression] segfault with pch and #pragma GCC diagnostic

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112319

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1

[Bug pch/112319] [14 Regression] segfault with pch and #pragma GCC diagnostic

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112319

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Lewis Hyatt <lhyatt@gcc.gnu.org>:

https://gcc.gnu.org/g:5d4abd9219dfa53b52b341255e99139bb6cad302

commit r14-5836-g5d4abd9219dfa53b52b341255e99139bb6cad302
Author: Lewis Hyatt <lhyatt@gmail.com>
Date:   Wed Nov 1 13:01:12 2023 -0400

    preprocessor: Reinitialize frontend parser after loading a PCH [PR112319]

    Since r14-2893, the frontend parser object needs to exist when running in
    preprocess-only mode, because pragma_lex() is now called in that mode and
    needs to make use of it. This is handled by calling c_init_preprocess() at
    startup. If -fpch-preprocess is in effect (commonly, because of
    -save-temps), a PCH file may be loaded during preprocessing, in which
    case the parser will be destroyed, causing the issue noted in the
    PR. Resolve it by reinitializing the frontend parser after loading the PCH.

    gcc/c-family/ChangeLog:

            PR pch/112319
            * c-ppoutput.cc (cb_read_pch): Reinitialize the frontend parser
            after loading a PCH.

    gcc/testsuite/ChangeLog:

            PR pch/112319
            * g++.dg/pch/pr112319.C: New test.
            * g++.dg/pch/pr112319.Hs: New test.
            * gcc.dg/pch/pr112319.c: New test.
            * gcc.dg/pch/pr112319.hs: New test.

[Bug pch/112319] [14 Regression] segfault with pch and #pragma GCC diagnostic

[lhyatt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112319

Lewis Hyatt <lhyatt at gcc dot gnu.org> changed:

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

--- Comment #4 from Lewis Hyatt <lhyatt at gcc dot gnu.org> ---
Fixed now.