[Bug c++/105300] New: segfault from static_assert with user-defined string suffix argument

[Bug c++/105300] New: segfault from static_assert with user-defined string suffix argument

[Jack at Applin dot US]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

            Bug ID: 105300
           Summary: segfault from static_assert with user-defined string
                    suffix argument
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: Jack at Applin dot US
  Target Milestone: ---

Created attachment 52824
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52824&action=edit
preprocessed source to reproduce the error

$ cat bad.ii
void operator""_x(const char *, unsigned long);
static_assert(false, "foo"_x);
$ g++ bad.ii
bad.ii:2:15: internal compiler error: Segmentation fault
    2 | static_assert(false, "foo"_x);
      |               ^~~~~
0xb0c67e crash_signal
        ../../src/gcc/toplev.c:327
0x7fb38e75951f ???
        ./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
0x7dd197 finish_static_assert(tree_node*, tree_node*, unsigned int, bool, bool)
        ../../src/gcc/cp/semantics.c:10134
0x15089c8 cp_parser_static_assert
        ../../src/gcc/cp/parser.c:15464
0xf9ed91 cp_parser_declaration
        ../../src/gcc/cp/parser.c:14164
0x149bba3 cp_parser_toplevel_declaration
        ../../src/gcc/cp/parser.c:14193
0x149bba3 cp_parser_translation_unit
        ../../src/gcc/cp/parser.c:4942
0x149bba3 c_parse_file()
        ../../src/gcc/cp/parser.c:45326
0x1489a5e c_common_parse_file()
        ../../src/gcc/c-family/c-opts.c:1218
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-11/README.Bugs> for instructions.
$ g++ --version
g++ (Ubuntu 11.2.0-7ubuntu2) 11.2.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[Bug c++/105300] segfault from static_assert with user-defined string suffix argument

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
                 CC|                            |marxin at gcc dot gnu.org
   Last reconfirmed|                            |2022-04-19
             Status|UNCONFIRMED                 |WAITING

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Is it really a valid code since clang rejects it?

$ clang++ pr105300.C -c
pr105300.C:2:27: error: string literal with user-defined suffix cannot be used
here
static_assert(false, "foo"_x);
                          ^
1 error generated.

[Bug c++/105300] segfault from static_assert with user-defined string suffix argument

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW

[Bug c++/105300] [10/11/12/13 Regression] segfault from static_assert with user-defined string suffix argument

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |10.5
      Known to fail|                            |6.1.0
            Summary|segfault from static_assert |[10/11/12/13 Regression]
                   |with user-defined string    |segfault from static_assert
                   |suffix argument             |with user-defined string
                   |                            |suffix argument
           Keywords|                            |diagnostic
      Known to work|                            |5.5.0

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
MSVC produces a decent error message:

<source>(2): error C3690: expected a string literal, but found a user-defined
string literal instead

Note best definition of the operator is just:
void operator""_x(const char *, decltype(sizeof(0)));
static_assert(false, "foo"_x);


Oh we started to ICE between GCC 5 and 6. Most likely when we started to print
out the message too.

[Bug c++/105300] [10/11/12/13 Regression] segfault from static_assert with user-defined string suffix argument

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Something like:
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 7c5f90b5127..185e0ac53f7 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -11203,6 +11203,13 @@ finish_static_assert (tree condition, tree message,
location_t location,
   if (check_for_bare_parameter_packs (condition))
     condition = error_mark_node;

+  if (TREE_CODE (message) != STRING_CST)
+    {
+      location_t mloc = cp_expr_loc_or_loc (message, location);
+      error_at (mloc, "user defined suffix not expected here");
+      return;
+    }
+
   if (instantiation_dependent_expression_p (condition))
     {
       /* We're in a template; build a STATIC_ASSERT and put it in


Should fix this I think ....

[Bug c++/105300] [10/11/12/13 Regression] segfault from static_assert with user-defined string suffix argument

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

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

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

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
We also crash on

  asm (""_x);

but not

extern ""_x { void g(); }

A more complete test:

// PR c++/105300

void operator""_x(const char *, decltype(sizeof(0)));
static_assert(false, "foo"_x);

extern ""_x { void g(); }

void
lol ()
{
  asm (""_x);
}

[Bug c++/105300] [10/11/12/13 Regression] segfault from static_assert with user-defined string suffix argument

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug c++/105300] [10/11/12/13 Regression] segfault from static_assert with user-defined string suffix argument

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:9f353b0c1dc9385ba8b8a64b65d66d5452383c11

commit r13-5390-g9f353b0c1dc9385ba8b8a64b65d66d5452383c11
Author: Marek Polacek <polacek@redhat.com>
Date:   Fri Nov 11 17:59:30 2022 -0500

    c++: Reject UDLs in certain contexts [PR105300]

    In this PR, we are crashing because we've encountered a UDL where a
    string-literal is expected.  This patch makes the parser reject string
    and character UDLs in all places where the grammar requires a
    string-literal and not a user-defined-string-literal.

    I've introduced two new wrappers; the existing cp_parser_string_literal
    was renamed to cp_parser_string_literal_common and should not be called
    directly.  finish_userdef_string_literal is renamed from
    cp_parser_userdef_string_literal.

            PR c++/105300

    gcc/c-family/ChangeLog:

            * c-pragma.cc (handle_pragma_message): Warn for CPP_STRING_USERDEF.

    gcc/cp/ChangeLog:

            * parser.cc: Remove unnecessary forward declarations.
            (cp_parser_string_literal): New wrapper.
            (cp_parser_string_literal_common): Renamed from
            cp_parser_string_literal.  Add a bool parameter.  Give an error
when
            UDLs are not permitted.
            (cp_parser_userdef_string_literal): New wrapper.
            (finish_userdef_string_literal): Renamed from
            cp_parser_userdef_string_literal.
            (cp_parser_primary_expression): Call
cp_parser_userdef_string_literal
            instead of cp_parser_string_literal.
            (cp_parser_linkage_specification): Move a variable declaration
closer
            to its first use.
            (cp_parser_static_assert): Likewise.
            (cp_parser_operator): Call cp_parser_userdef_string_literal instead
of
            cp_parser_string_literal.
            (cp_parser_asm_definition): Move a variable declaration closer to
its
            first use.
            (cp_parser_asm_specification_opt): Move variable declarations
closer to
            their first use.
            (cp_parser_asm_operand_list): Likewise.
            (cp_parser_asm_clobber_list): Likewise.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/udlit-error1.C: New test.

[Bug c++/105300] [10/11/12 Regression] segfault from static_assert with user-defined string suffix argument

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED
            Summary|[10/11/12/13 Regression]    |[10/11/12 Regression]
                   |segfault from static_assert |segfault from static_assert
                   |with user-defined string    |with user-defined string
                   |suffix argument             |suffix argument

--- Comment #6 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed for GCC 13.  I don't think I want to backport the patch.

[Bug c++/105300] [10/11/12 Regression] segfault from static_assert with user-defined string suffix argument

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105300

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |stevenxia990430 at gmail dot com

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
*** Bug 109459 has been marked as a duplicate of this bug. ***