[Bug c/105207] New: C preprocessor: splicing physical source lines to form logical source lines may not work

[Bug c/105207] New: C preprocessor: splicing physical source lines to form logical source lines may not work

[pavel.morozkin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105207

            Bug ID: 105207
           Summary: C preprocessor: splicing physical source lines to form
                    logical source lines may not work
           Product: gcc
           Version: 11.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pavel.morozkin at gmail dot com
  Target Milestone: ---

Sample code:
xxx \
#error

Invocation:
$ gcc t6.c -E

Actual output:
xxx
 #error

Expected output:
xxx #error

[Bug c/105207] C preprocessor: splicing physical source lines to form logical source lines may not work

[pavel.morozkin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105207

--- Comment #1 from Pavel M <pavel.morozkin at gmail dot com> ---
The same behavior with:
xxx \
error

Expected:
xxx error

Actual:
xxx
 error

[Bug c/105207] Translation phase 2: splicing physical source lines to form logical source lines may not work

[pavel.morozkin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105207

Pavel M <pavel.morozkin at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|C preprocessor: splicing    |Translation phase 2:
                   |physical source lines to    |splicing physical source
                   |form logical source lines   |lines to form logical
                   |may not work                |source lines may not work

--- Comment #2 from Pavel M <pavel.morozkin at gmail dot com> ---
Actually the issue is not related to the preprocessor. It is relayed to the
translation phase 2. Please

[Bug preprocessor/105207] Translation phase 2: splicing physical source lines to form logical source lines may not work

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105207

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note this only matters if you preprocessing the file yourself; that is
-save-temps works correctly and errors out that there is a stray '#' in
program.

[Bug preprocessor/105207] Translation phase 2: splicing physical source lines to form logical source lines may not work

[pavel.morozkin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105207

--- Comment #4 from Pavel M <pavel.morozkin at gmail dot com> ---
To: Andrew Pinski

At the 1st glance I expected to see that -E produces the output after splicing
is done (i.e. xxx #error). However, the "preprocessing only" is out of scope of
the C11. As stackoverflow.com user rici said: "Serializing the stream of tokens
back into a character string, which is what gcc -E does, is not required or
even mentioned by the standard, and does not form part of the translation
process specified by the standard".

Hence, per C11 the 105207 is "not a problem".

However, per quality-of-implementation matter maybe it will be useful to make
-E produce the output after splicing is done (i.e. xxx #error). What do you
think?

[Bug preprocessor/105207] Translation phase 2: splicing physical source lines to form logical source lines may not work

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105207

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

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

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 55242.

*** This bug has been marked as a duplicate of bug 55242 ***