[Bug preprocessor/82359] #line does not allow C++14 quotes in number

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82359

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Joseph Myers <jsm28@gcc.gnu.org>:

https://gcc.gnu.org/g:b24d8acbfffe30f40e280f11f23adac81b1e7f0c

commit r12-302-gb24d8acbfffe30f40e280f11f23adac81b1e7f0c
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Thu Apr 29 19:50:47 2021 +0000

    preprocessor: Handle digit separators in #line [PR82359]

    As reported in bug 82359, the preprocessor does not allow C++ digit
    separators in the line number in a #line directive, despite the
    standard syntax for that directive using digit-sequence which allows
    digit separators.

    There is some confusion in that bug about whether C++ is meant to
    allow digit separators there or not, but the last comment there
    suggests they are meant to be allowed, and the version of digit
    separators accepted for C2X at the March meeting explicitly mentions
    digit separators in the #line specification to avoid any ambiguity
    there.

    This patch thus adds code to handle digit separators in the line
    number in #line, as part of the preparation for enabling digit
    separators in C2X mode.  The code changed does not contain any
    conditionals for whether digit separators are supported in the chosen
    language version, because that was handled earlier in pp-number lexing
    and if they aren't supported they won't appear in the string passed to
    that function.  It does however make sure not to allow adjacent digit
    separators because those are only handled at a later stage of lexing
    at present.  (Problems with how certain source character sequences
    involving digit separators that don't actually match the pp-number
    syntax get lexed as a pp-number and only diagnosed later, if at all,
    are bugs 83873 and 97604, to be addressed separately.)

    Making the change in this location will have the effect of allowing
    digit separators in the "# <line-number> <file> <flags>" form of
    directive as well as #line; I don't think that's a problem.

    Bootstrapped with no regressions for x86_64-pc-linux-gnu.

    libcpp/
            PR preprocessor/82359
            * directives.c (strtolinenum): Handle digit separators.

    gcc/testsuite/
            PR preprocessor/82359
            * g++.dg/cpp1y/digit-sep-line.C,
            g++.dg/cpp1y/digit-sep-line-neg.C: New tests.