[cfe-commits] [patch][preprocessor] Remember to exit <command line>

[Chandler Carruth]

On Tue, Dec 1, 2009 at 9:43 AM, Rafael Espindola <espindola at google.com> wrote:
>> Perhaps its just my ignorance of how preprocessors work, but I don't
>> see why this is needed. GCC doesn't introduce such a line:
>>
>> % gcc -E test.c
>> # 1 "test.c"
>> # 1 "<built-in>"
>> # 1 "<command-line>"
>> # 1 "test.c"
>> int main(int argc, char *argv[]) {
>>  return 0;
>> }
>>
>> It's entirely likely I just don't understand the directives being
>> produced here, as there are other differences.
>
> The difference is how gcc changes from one "file" to another. Note
> that it never prints a number after the file name. According to
> libcpp/directives.c:do_linemarker that gets mapped to
> "LC_RENAME_VERBATIM" which, if I understand correctly, doesn't affect
> the stack of files being processed.
>
> If a number is present, they have the following meaning: 1 in
> LC_ENTER, 2 is LC_LEAVE and everything else is also
> LC_RENAME_VERBATIM.
>
> So, from the gcc output everything is a LC_RENAME_VERBATIM. OK.
> From the current clang output we have
>
> # 1 "test.c"                     LC_RENAME_VERBATIM
> # 1 "test.c" 1                   LC_ENTER
> # 1 "<built-in>" 1               LC_ENTER
> # 1 "<built-in>" 3               LC_RENAME_VERBATIM
> # 113 "<built-in>" 3             LC_RENAME_VERBATIM
> # 113 "<command line>" 1         LC_ENTER
> # 1 "test.c" 2                   LC_LEAVE
>
>
> Notice that we leave from "<command line>" into "test.c" without
> passing by "<built-in>" that we passed on the way in.

And now I am properly educated! =D LGTM. Maybe a comment that this is
closing the command line section? "1" and "2" are far less clear that
LC_ENTER and LC_LEAVE.

-Chandler

>
>> -Chandler
>>
>
> Cheers,
> --
> Rafael Ávila de Espíndola
>