Hi,
On Thu, Sep 05 2019, Nathan Sidwell wrote:
> This fixes 91639.
> #include processing needs to rewind by one line before doing the
> inclusion, so that that happens on the #include line itself. Except
> that the lexer doesn't increment the lineno on the last \n of a file --
> because there's no point.
>
> So we had code in the include path to figure out that special case and
> not rewind. I broke that.
>
> Rather than repair it there, I decided it simpler to make the lexer
> always advance when lexing a #include line. I did consider not even
> making that conditional, but the unstacking code looked a bit hairy to
> correctly rewind in those cases (or we simply waste linemap space).
>
> This ends up making the include rewinding simpler -- there are still
> cases it shouldn't.
>
> Applying to trunk.
>
> --
> Nathan Sidwell
> 2019-09-05 Nathan Sidwell <nat...@acm.org>
>
> libcpp/
> PR preprocessor/91639
> * directives.c (do_include_common): Tell lexer we're a #include.
> * files.c (_cpp_stack_file): Lexer will have always incremented.
> * internal.h (struct cpp_context): Extend in_directive's
> semantics.
> * lex.c (_cpp_lex_direct): Increment line for final \n when lexing
> for an ISO #include.
> * line-map.c (linemap_line_start): Remember if we overflowed.
>
> gcc/testsuite/
> PR preprocessor/91639
> * c-c++-common/cpp/pr91639.c: New.
> * c-c++-common/cpp/pr91639-one.h: New.
> * c-c++-common/cpp/pr91639-two.h: New.
unfortunately, this has caused PR 91991.
Martin
>
> Index: libcpp/directives.c
> ===================================================================
> --- libcpp/directives.c (revision 275373)
> +++ libcpp/directives.c (working copy)
> @@ -819,4 +819,8 @@ do_include_common (cpp_reader *pfile, en
> pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
>
> + /* Tell the lexer this is an include directive -- we want it to
> + increment the line number even if this is the last line of a file. */
> + pfile->state.in_directive = 2;
> +
> fname = parse_include (pfile, &angle_brackets, &buf, &location);
> if (!fname)
> Index: libcpp/files.c
> ===================================================================
> --- libcpp/files.c (revision 275373)
> +++ libcpp/files.c (working copy)
> @@ -939,23 +939,14 @@ _cpp_stack_file (cpp_reader *pfile, _cpp
> pfile->mi_cmacro = 0;
>
> - /* Compensate for the increment in linemap_add that occurs when in
> - do_file_change. In the case of a normal #include, we're
> - currently at the start of the line *following* the #include. A
> - separate location_t for this location makes no sense (until we do
> - the LC_LEAVE), and complicates LAST_SOURCE_LINE_LOCATION. This
> - does not apply if we found a PCH file (in which case linemap_add
> - is not called) or we were included from the command-line. In the
> - case that the #include is the last line in the file,
> - highest_location still points to the current line, not the start
> - of the next line, so we do not decrement in this case. See
> - plugin/location-overflow-test-pr83173.h for an example. */
> - bool decremented = false;
> - if (file->pchname == NULL && file->err_no == 0 && type < IT_DIRECTIVE_HWM)
> - {
> - decremented = (pfile->line_table->highest_line
> - == pfile->line_table->highest_location);
> - if (decremented)
> - pfile->line_table->highest_location--;
> - }
> + /* In the case of a normal #include, we're now at the start of the
> + line *following* the #include. A separate location_t for this
> + location makes no sense, until we do the LC_LEAVE.
> +
> + This does not apply if we found a PCH file, we're not a regular
> + include, or we ran out of locations. */
> + if (file->pchname == NULL
> + && type < IT_DIRECTIVE_HWM
> + && pfile->line_table->highest_location != LINE_MAP_MAX_LOCATION - 1)
> + pfile->line_table->highest_location--;
>
> /* Add line map and do callbacks. */
> Index: libcpp/internal.h
> ===================================================================
> --- libcpp/internal.h (revision 275373)
> +++ libcpp/internal.h (working copy)
> @@ -235,5 +235,6 @@ struct cpp_context
> struct lexer_state
> {
> - /* Nonzero if first token on line is CPP_HASH. */
> + /* 1 if we're handling a directive. 2 if it's an include-like
> + directive. */
> unsigned char in_directive;
>
> Index: libcpp/lex.c
> ===================================================================
> --- libcpp/lex.c (revision 275373)
> +++ libcpp/lex.c (working copy)
> @@ -2772,5 +2772,11 @@ _cpp_lex_direct (cpp_reader *pfile)
>
> case '\n':
> - if (buffer->cur < buffer->rlimit)
> + /* Increment the line, unless this is the last line ... */
> + if (buffer->cur < buffer->rlimit
> + /* ... or this is a #include, (where _cpp_stack_file needs to
> + unwind by one line) ... */
> + || (pfile->state.in_directive > 1
> + /* ... except traditional-cpp increments this elsewhere. */
> + && !CPP_OPTION (pfile, traditional)))
> CPP_INCREMENT_LINE (pfile, 0);
> buffer->need_line = true;
> Index: libcpp/line-map.c
> ===================================================================
> --- libcpp/line-map.c (revision 275373)
> +++ libcpp/line-map.c (working copy)
> @@ -765,5 +765,9 @@ linemap_line_start (line_maps *set, line
> macro tokens. */
> if (r >= LINE_MAP_MAX_LOCATION)
> - return 0;
> + {
> + /* Remember we overflowed. */
> + set->highest_line = set->highest_location = LINE_MAP_MAX_LOCATION - 1;
> + return 0;
> + }
>
> set->highest_line = r;
> Index: gcc/testsuite/c-c++-common/cpp/pr91639-one.h
> ===================================================================
> --- gcc/testsuite/c-c++-common/cpp/pr91639-one.h (revision 0)
> +++ gcc/testsuite/c-c++-common/cpp/pr91639-one.h (working copy)
> @@ -0,0 +1,2 @@
> +one
> +#include "pr91639-two.h"
> Index: gcc/testsuite/c-c++-common/cpp/pr91639-two.h
> ===================================================================
> --- gcc/testsuite/c-c++-common/cpp/pr91639-two.h (revision 0)
> +++ gcc/testsuite/c-c++-common/cpp/pr91639-two.h (working copy)
> @@ -0,0 +1 @@
> +two
> Index: gcc/testsuite/c-c++-common/cpp/pr91639.c
> ===================================================================
> --- gcc/testsuite/c-c++-common/cpp/pr91639.c (revision 0)
> +++ gcc/testsuite/c-c++-common/cpp/pr91639.c (working copy)
> @@ -0,0 +1,9 @@
> +/* PR91639 Line markers for an end-of-file #include */
> +/* { dg-do preprocess } */
> +/* { dg-additional-options -Wno-pedantic } */
> +/* { dg-additional-files {pr91639-one.h pr91639-two.h} } */
> +
> +#include "pr91639-one.h"
> +main
> +
> +/* { dg-final { scan-file pr91639.i "# 1 \"\[^\n\"\]*pr91639-one.h\"
> 1\none\n# 1 \"\[^\n\"\]*pr91639-two.h\" 1\ntwo\n# 3
> \"\[^\n\"\]*pr91639-one.h\" 2\n# 7 \"\[^\n\"\]*pr91639.c\" 2\nmain\n" } } */
