[Bug c++/60249] New: [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[Bug c++/60249] New: [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[reichelt at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

            Bug ID: 60249
           Summary: [c++11] Compiler goes into semi-infinite loop with
                    wrong usage of user defined string literals
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: reichelt at gcc dot gnu.org

The following invalid code snippet (compiled with "-std=c++11") triggers
an ICE since GCC 4.7.0 (when user defined literals were introduced):

====================================
decltype( ""_ ) x;
====================================

The compiler goes into a loop and finally crashes:

bug.cc:1:11: error: unable to find string literal operator 'operator""_'
 decltype( ""_ ) x;
           ^
bug.cc:1:11: warning: unknown escape sequence: '\257'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'

[ snip more than a million lines ]

bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: warning: unknown escape sequence: '\000'
bug.cc:1:11: internal compiler error: Segmentation fault
0xba529f crash_signal
    ../../gcc/gcc/toplev.c:337
0x114a0f8 convert_escape
    ../../gcc/libcpp/charset.c:1271
0x114a0f8 cpp_interpret_string(cpp_reader*, cpp_string const*, unsigned long,
cpp_string*, cpp_ttype)
    ../../gcc/libcpp/charset.c:1435
0x6a4f63 cp_parser_string_literal
    ../../gcc/gcc/cp/parser.c:3653
0x6afa21 cp_parser_primary_expression
    ../../gcc/gcc/cp/parser.c:4224
0x6b20dd cp_parser_postfix_expression
    ../../gcc/gcc/cp/parser.c:5971
0x6b50b6 cp_parser_unary_expression
    ../../gcc/gcc/cp/parser.c:7170
0x6b5ddf cp_parser_binary_expression
    ../../gcc/gcc/cp/parser.c:7874
0x6b62d1 cp_parser_assignment_expression
    ../../gcc/gcc/cp/parser.c:8112
0x6b8684 cp_parser_expression
    ../../gcc/gcc/cp/parser.c:8274
0x6b36cd cp_parser_decltype_expr
    ../../gcc/gcc/cp/parser.c:11924
0x6b36cd cp_parser_decltype
    ../../gcc/gcc/cp/parser.c:12003
0x6cb40f cp_parser_simple_type_specifier
    ../../gcc/gcc/cp/parser.c:14533
0x6a942d cp_parser_type_specifier
    ../../gcc/gcc/cp/parser.c:14380
0x6c2b40 cp_parser_decl_specifier_seq
    ../../gcc/gcc/cp/parser.c:11547
0x6c9739 cp_parser_simple_declaration
    ../../gcc/gcc/cp/parser.c:11137
0x6acc03 cp_parser_block_declaration
    ../../gcc/gcc/cp/parser.c:11086
0x6d3ea2 cp_parser_declaration
    ../../gcc/gcc/cp/parser.c:10983
0x6d2b98 cp_parser_declaration_seq_opt
    ../../gcc/gcc/cp/parser.c:10869
0x6d443a cp_parser_translation_unit
    ../../gcc/gcc/cp/parser.c:4014
Please submit a full bug report, [etc.]

Although error-recovery bugs usually end up as P5, I'd vote for
prioritizing this one higher: the amount of output (60 MB in my case)
is worse than the crash.

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |3dw4rd at verizon dot net

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Maybe Ed can have a look.

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Ed?

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[3dw4rd at verizon dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #3 from Ed Smith-Rowland <3dw4rd at verizon dot net> ---
On 06/25/2014 01:45 PM, paolo.carlini at oracle dot com wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249
>
> --- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> ---
> Ed?
>
Paolo,
I'm really struggling with this and some decltype ud literal bugs that I 
think are related.
I'll give it a last look today.
I may have to get some help.
I'll be more exact about where I am stuck tonight.
I'm having trouble getting time to work on these.
Ed

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[3dw4rd at verizon dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #4 from Ed Smith-Rowland <3dw4rd at verizon dot net> ---
Created attachment 33022
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33022&action=edit
Patch 58781, 59867, 60249, ...

I think I got it.

Don't mess with the token stream.

PR C++/58781 - Unicode strings broken in a strange way
PR C++/59867 - Template string literal loses first symbol
PR C++/60249 - Compiler goes into semi-infinite loop with wrong usage of user
defined string literals
Plus I fixed an misleading error message for string literal operator templates
(not available in C++11).

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Patch looks *great*. If it works, please send it to mailing list ASAP.

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[3dw4rd at verizon dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #6 from Ed Smith-Rowland <3dw4rd at verizon dot net> ---
On 06/27/2014 05:39 PM, paolo.carlini at oracle dot com wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249
>
> --- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> ---
> Patch looks *great*. If it works, please send it to mailing list ASAP.
>
I think I finally got these weird user-defined string literal bugs. 
"Don't cross the streams!"

Dr. Egon Spengler

PR C++/58781  <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58781>  - Unicode
strings broken in a strange way
PR C++/59867  <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59867>  - Template
string literal loses first symbol
PR C++/60249  <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249>  - Compiler
goes into semi-infinite loop with wrong usage of user defined string literals
Plus I fixed an misleading error message for string literal operator templates
(not available in C++11).

Built and tested clean on x86_64-linux.

OK?

I would also like to apply this to 4.9.

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[3dw4rd at verizon dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #7 from Ed Smith-Rowland <3dw4rd at verizon dot net> ---
Created attachment 33026
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33026&action=edit
patch_from_hell

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #8 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Thanks, but in general I would recommend sending patches to gcc-patches in a
separate email, with a clear [C++ Patch] or something similar in the subject.
Also, please minimize jokes and other redundant content, we already have
setious issues with lost patches, old bugs remaining umfixed for ages, etc,
without.

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[3dw4rd at verizon dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #9 from Ed Smith-Rowland <3dw4rd at verizon dot net> ---
On 06/28/2014 10:03 AM, paolo.carlini at oracle dot com wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249
>
> --- Comment #8 from Paolo Carlini <paolo.carlini at oracle dot com> ---
> Thanks, but in general I would recommend sending patches to gcc-patches in a
> separate email, with a clear [C++ Patch] or something similar in the subject.
> Also, please minimize jokes and other redundant content, we already have
> setious issues with lost patches, old bugs remaining umfixed for ages, etc,
> without.
>
Sorry about the noise.
Should I send a new cleaner message with new subject?

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[3dw4rd at verizon dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #10 from Ed Smith-Rowland <3dw4rd at verizon dot net> ---
On 06/28/2014 10:03 AM, paolo.carlini at oracle dot com wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249
>
> --- Comment #8 from Paolo Carlini <paolo.carlini at oracle dot com> ---
> Thanks, but in general I would recommend sending patches to gcc-patches in a
> separate email, with a clear [C++ Patch] or something similar in the subject.
> Also, please minimize jokes and other redundant content, we already have
> setious issues with lost patches, old bugs remaining umfixed for ages, etc,
> without.
>

Sorry about the noise.
Should I send a new cleaner message with new subject?

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[emsr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #11 from emsr at gcc dot gnu.org ---
Author: emsr
Date: Tue Jul  1 03:13:17 2014
New Revision: 212186

URL: https://gcc.gnu.org/viewcvs?rev=212186&root=gcc&view=rev
Log:
cp/

2014-06-28  Edward Smith-Rowland  <3dw4rd@verizon.net>

    PR c++/58781
    PR c++/60249
    PR c++/59867
    * parser.c (cp_parser_userdef_string_literal()): Take a tree
    not a cp_token*. (cp_parser_string_literal(): Don't hack
    the token stream!


testsuite/

2014-06-28  Edward Smith-Rowland  <3dw4rd@verizon.net>

    PR c++/58781
    PR c++/60249
    PR c++/59867
    * testsuite/g++.dg/cpp0x/pr58781.C: New.
    * testsuite/g++.dg/cpp0x/pr60249.C: New.
    * testsuite/g++.dg/cpp1y/pr59867.C: New.



Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/pr58781.C
    trunk/gcc/testsuite/g++.dg/cpp0x/pr60249.C
    trunk/gcc/testsuite/g++.dg/cpp1y/pr59867.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/parser.c
    trunk/gcc/testsuite/ChangeLog

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[emsr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

--- Comment #12 from emsr at gcc dot gnu.org ---
Author: emsr
Date: Tue Jul  1 05:30:34 2014
New Revision: 212188

URL: https://gcc.gnu.org/viewcvs?rev=212188&root=gcc&view=rev
Log:
cp/

2014-06-28  Edward Smith-Rowland  <3dw4rd@verizon.net>

    PR c++/58781
    PR c++/60249
    PR c++/59867
    * parser.c (cp_parser_userdef_string_literal()): Take a tree
    not a cp_token*. (cp_parser_string_literal(): Don't hack
    the token stream!

testsuite/

2014-06-28  Edward Smith-Rowland  <3dw4rd@verizon.net>

    PR c++/58781
    PR c++/60249
    PR c++/59867
    * testsuite/g++.dg/cpp0x/pr58781.C: New.
    * testsuite/g++.dg/cpp0x/pr60249.C: New.
    * testsuite/g++.dg/cpp1y/pr59867.C: New.


Added:
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/cpp0x/pr58781.C
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/cpp0x/pr60249.C
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/cpp1y/pr59867.C
Modified:
    branches/gcc-4_9-branch/gcc/cp/ChangeLog
    branches/gcc-4_9-branch/gcc/cp/parser.c
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog

[Bug c++/60249] [c++11] Compiler goes into semi-infinite loop with wrong usage of user defined string literals

[emsr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60249

emsr at gcc dot gnu.org changed:

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

--- Comment #13 from emsr at gcc dot gnu.org ---
Fixed.