https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70270
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|preprocessor |c
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This actually coming from the C/C++ common part of the front-end and not from
the preprocessor:
void
pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
{
size_t to_file_len = strlen (dir);
unsigned char *to_file_quoted =
(unsigned char *) alloca (to_file_len * 4 + 1);
unsigned char *p;
/* cpp_quote_string does not nul-terminate, so we have to do it ourselves.
*/
p = cpp_quote_string (to_file_quoted, (const unsigned char *) dir,
to_file_len);
*p = '\0';
fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
}
And when read back in it invokes cb_dir_change:
cb->dir_change = cb_dir_change;
...
void
cb_dir_change (cpp_reader * ARG_UNUSED (pfile), const char *dir)
{
if (!set_src_pwd (dir))
warning (0, "too late for # directive to set debug directory");
}
So I don't think it changes the different line-map behavior at all.
The first two lines are special in the preprocessed source for libcpp:
/* For preprocessed files, if the very first characters are
'#<SPACE>[01]<SPACE>', then handle a line directive so we know the
original file name. This will generate file_change callbacks,
which the front ends must handle appropriately given their state of
initialization. We peek directly into the character buffer, so
that we're not confused by otherwise-skipped white space &
comments. We can be very picky, because this should have been
machine-generated text (by us, no less). This way we do not
interfere with the module directive state machine. */
....
/* For preprocessed files, if the tokens following the first filename
line is of the form # <line> "/path/name//", handle the
directive so we know the original current directory.
As with the first line peeking, we can do this without lexing by
being picky. */
So I don't think the line mapping changes at all with this.
