preprocessor: Reimplement directives only processing, support raw literals.

The existing directives-only code (a) punched a hole through the
libcpp interface and (b) didn't support raw string literals.  This
reimplements this preprocessing mode.  I added a proper callback
interface, and adjusted c-ppoutput to use it.  Sadly I cannot get rid
of the libcpp/internal.h include for unrelated reasons.

The new scanner is in lex.x, and works doing some backwards scanning
when it finds a charater of interest.  This reduces the number of
cases one has to deal with in forward scanning.  It may have different
failure mode than forward scanning on bad tokenization.

Finally, Moved some cpp tests from the c-specific dg.gcc/cpp directory
to the c-c++-common/cpp shared directory,

	libcpp/
	* directives-only.c: Delete.
	* Makefile.in (libcpp_a_OBJS, libcpp_a_SOURCES): Remove it.
	* include/cpplib.h (enum CPP_DO_task): New enum.
	(cpp_directive_only_preprocess): Declare.
	* internal.h (_cpp_dir_only_callbacks): Delete.
	(_cpp_preprocess_dir_only): Delete.
	* lex.c (do_peek_backslask, do_peek_next, do_peek_prev): New.
	(cpp_directives_only_process): New implementation.

	gcc/c-family/
	Reimplement directives only processing.
	* c-ppoutput.c (token_streamer): Ne.
	(directives_only_cb): New.  Swallow ...
	(print_lines_directives_only): ... this.
	(scan_translation_unit_directives_only): Reimplment using the
	published interface.

	gcc/testsuite/
	* gcc.dg/cpp/counter-[23].c: Move to c-c+_-common/cpp.
	* gcc.dg/cpp/dir-only-*: Likewise.
	* c-c++-common/cpp/dir-only-[78].c: New.

1 files changed, 0 insertions, 240 deletions

diff --git a/libcpp/directives-only.c b/libcpp/directives-only.c
deleted file mode 100644
index 5eac118..0000000
--- a/libcpp/directives-only.c
+++ /dev/null
@@ -1,240 +0,0 @@
-/* CPP Library - directive only preprocessing for distributed compilation.
-   Copyright (C) 2007-2020 Free Software Foundation, Inc.
-   Contributed by Ollie Wild <aaw@google.com>.
-
-This program is free software; you can redistribute it and/or modify it
-under the terms of the GNU General Public License as published by the
-Free Software Foundation; either version 3, or (at your option) any
-later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program; see the file COPYING3.  If not see
-<http://www.gnu.org/licenses/>.  */
-
-#include "config.h"
-#include "system.h"
-#include "cpplib.h"
-#include "internal.h"
-
-/* DO (Directive only) flags. */
-#define DO_BOL		 (1 << 0) /* At the beginning of a logical line. */
-#define DO_STRING	 (1 << 1) /* In a string constant. */
-#define DO_CHAR		 (1 << 2) /* In a character constant. */
-#define DO_BLOCK_COMMENT (1 << 3) /* In a block comment. */
-#define DO_LINE_COMMENT	 (1 << 4) /* In a single line "//-style" comment. */
-
-#define DO_LINE_SPECIAL (DO_STRING | DO_CHAR | DO_LINE_COMMENT)
-#define DO_SPECIAL	(DO_LINE_SPECIAL | DO_BLOCK_COMMENT)
-
-/* Writes out the preprocessed file, handling spacing and paste
-   avoidance issues.  */
-void
-_cpp_preprocess_dir_only (cpp_reader *pfile,
-			  const struct _cpp_dir_only_callbacks *cb)
-{
-  struct cpp_buffer *buffer;
-  const unsigned char *cur, *base, *next_line, *rlimit;
-  cppchar_t c, last_c;
-  unsigned flags;
-  linenum_type lines;
-  int col;
-  location_t loc;
-
- restart:
-  /* Buffer initialization ala _cpp_clean_line(). */
-  buffer = pfile->buffer;
-  buffer->cur_note = buffer->notes_used = 0;
-  buffer->cur = buffer->line_base = buffer->next_line;
-  buffer->need_line = false;
-
-  /* This isn't really needed.  It prevents a compiler warning, though. */
-  loc = pfile->line_table->highest_line;
-
-  /* Scan initialization. */
-  next_line = cur = base = buffer->cur;
-  rlimit = buffer->rlimit;
-  flags = DO_BOL;
-  lines = 0;
-  col = 1;
-
-  for (last_c = '\n', c = *cur; cur < rlimit; last_c = c, c = *++cur, ++col)
-    {
-      /* Skip over escaped newlines. */
-      if (__builtin_expect (c == '\\', false))
-	{
-	  const unsigned char *tmp = cur + 1;
-
-	  while (is_nvspace (*tmp) && tmp < rlimit)
-	    tmp++;
-	  if (*tmp == '\r')
-	    tmp++;
-	  if (*tmp == '\n' && tmp < rlimit)
-	    {
-	      CPP_INCREMENT_LINE (pfile, 0);
-	      lines++;
-	      col = 0;
-	      cur = tmp;
-	      c = last_c;
-	      continue;
-	    }
-	}
-
-      if (__builtin_expect (last_c == '#', false) && !(flags & DO_SPECIAL))
-	{
-	  if (c != '#' && (flags & DO_BOL))
-	  {
-	    class line_maps *line_table;
-
-	    if (!pfile->state.skipping && next_line != base)
-	      cb->print_lines (lines, base, next_line - base);
-
-	    /* Prep things for directive handling. */
-	    buffer->next_line = cur;
-	    buffer->need_line = true;
-	    _cpp_get_fresh_line (pfile);
-
-	    /* Ensure proper column numbering for generated error messages. */
-	    buffer->line_base -= col - 1;
-
-	    _cpp_handle_directive (pfile, false /* ignore indented */);
-
-	    /* Sanitize the line settings.  Duplicate #include's can mess
-	       things up. */
-	    line_table = pfile->line_table;
-	    line_table->highest_location = line_table->highest_line;
-
-	    /* The if block prevents us from outputing line information when
-	       the file ends with a directive and no newline.  Note that we
-	       must use pfile->buffer, not buffer. */
-	    if (pfile->buffer->next_line < pfile->buffer->rlimit)
-	      cb->maybe_print_line (pfile->line_table->highest_line);
-
-	    goto restart;
-	  }
-
-	  flags &= ~DO_BOL;
-	  pfile->mi_valid = false;
-	}
-      else if (__builtin_expect (last_c == '/', false) \
-	       && !(flags & DO_SPECIAL) && c != '*' && c != '/')
-	{
-	  /* If a previous slash is not starting a block comment, clear the
-	     DO_BOL flag.  */
-	  flags &= ~DO_BOL;
-	  pfile->mi_valid = false;
-	}
-
-      switch (c)
-	{
-	case '/':
-	  if ((flags & DO_BLOCK_COMMENT) && last_c == '*')
-	    {
-	      flags &= ~DO_BLOCK_COMMENT;
-	      c = 0;
-	    }
-	  else if (!(flags & DO_SPECIAL) && last_c == '/')
-	    flags |= DO_LINE_COMMENT;
-	  else if (!(flags & DO_SPECIAL))
-	    /* Mark the position for possible error reporting. */
-	    loc = linemap_position_for_column (pfile->line_table, col);
-
-	  break;
-
-	case '*':
-	  if (!(flags & DO_SPECIAL))
-	    {
-	      if (last_c == '/')
-		flags |= DO_BLOCK_COMMENT;
-	      else
-		{
-		  flags &= ~DO_BOL;
-		  pfile->mi_valid = false;
-		}
-	    }
-
-	  break;
-
-	case '\'':
-	case '"':
-	  {
-	    unsigned state = (c == '"') ? DO_STRING : DO_CHAR;
-
-	    if (!(flags & DO_SPECIAL))
-	      {
-		flags |= state;
-		flags &= ~DO_BOL;
-		pfile->mi_valid = false;
-	      }
-	    else if ((flags & state) && last_c != '\\')
-	      flags &= ~state;
-
-	    break;
-	  }
-
-	case '\\':
-	  {
-	    if ((flags & (DO_STRING | DO_CHAR)) && last_c == '\\')
-	      c = 0;
-
-	    if (!(flags & DO_SPECIAL))
-	      {
-		flags &= ~DO_BOL;
-		pfile->mi_valid = false;
-	      }
-
-	    break;
-	  }
-
-	case '\n':
-	  CPP_INCREMENT_LINE (pfile, 0);
-	  lines++;
-	  col = 0;
-	  flags &= ~DO_LINE_SPECIAL;
-	  if (!(flags & DO_SPECIAL))
-	    flags |= DO_BOL;
-	  break;
-
-	case '#':
-	  next_line = cur;
-	  /* Don't update DO_BOL yet. */
-	  break;
-
-	case ' ': case '\t': case '\f': case '\v': case '\0':
-	  break;
-
-	default:
-	  if (!(flags & DO_SPECIAL))
-	    {
-	      flags &= ~DO_BOL;
-	      pfile->mi_valid = false;
-	    }
-	  break;
-	}
-    }
-
-  if (flags & DO_BLOCK_COMMENT)
-    cpp_error_with_line (pfile, CPP_DL_ERROR, loc, 0, "unterminated comment");
-
-  if (!pfile->state.skipping && cur != base)
-    {
-      /* If the file was not newline terminated, add rlimit, which is
-         guaranteed to point to a newline, to the end of our range.  */
-      if (cur[-1] != '\n')
-	{
-	  cur++;
-	  CPP_INCREMENT_LINE (pfile, 0);
-	  lines++;
-	}
-
-      cb->print_lines (lines, base, cur - base);
-    }
-
-  _cpp_pop_buffer (pfile);
-  if (pfile->buffer)
-    goto restart;
-}