[Bug c++/111072] New: Splicing at the end fails

[Bug c++/111072] New: Splicing at the end fails

[verodeving at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111072

            Bug ID: 111072
           Summary: Splicing at the end fails
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: verodeving at gmail dot com
  Target Milestone: ---

The following code fails under GCC(trunk) and the compiler options -Wall
-Werror -Wextra -pedantic-errors -Wpedantic -O3 -std=c++23(untested under other
compiler options or other GCC versions):

int \
 a;

An example of the failure can be seen at https://godbolt.org/z/WhKK7rYne

This behaviour is incorrect because https://eel.is/c++draft/lex.phases#1.2
mentions the following:

- A source file that is not empty and that does not end in a new-line
character, or that ends in a splice, shall be processed as if an additional
new-line character were appended to the file.

Therefore, the backslash at the end of the file shouldn't error because it
should behave as a new line was appended at the end of the file, according to
the mentioned standard paragraph.

[Bug preprocessor/111072] Splicing at the end fails

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111072

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-08-19
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note C17 has:
A source file that is not empty shall end in a new-line character, which shall
not be immediately preceded by a backslash character before any such splicing
takes place.

C++11, C++17 and C++20:
A source file that is not empty and that does not end in a new-line character,
or that ends in a new-line character immediately preceded by a backslash
character before any such splicing takes place, shall be processed as if an
additional new-line character were appended to the file.

So this is a difference between C++ and C :).

And GCC just misses that point out.