- fpars = fparser1;
-#endif
-
- /* Loop over lines in the standard parser file. */
-
- while (1)
- {
- int write_line = 1;
-
- c = getc (fpars);
-
- /* See if the line starts with `#line.
- If so, set write_line to 0. */
- if (nolinesflag)
- if (c == '#')
- {
- c = getc (fpars);
- if (c == 'l')
- {
- c = getc (fpars);
- if (c == 'i')
- {
- c = getc (fpars);
- if (c == 'n')
- {
- c = getc (fpars);
- if (c == 'e')
- write_line = 0;
- else
- fprintf (ftable, "#lin");
- }
- else
- fprintf (ftable, "#li");
- }
- else
- fprintf (ftable, "#l");
- }
- else
- fprintf (ftable, "#");
- }
-
- /* now write out the line... */
- for (; c != '\n' && c != EOF; c = getc (fpars))
- if (write_line)
- {
- if (c == '$')
- {
- /* `$' in the parser file indicates where to put the actions.
- Copy them in at this point. */
- rewind (faction);
- for (c = getc (faction); c != EOF; c = getc (faction))
- putc (c, ftable);
- }
- else
- putc (c, ftable);
- }
- if (c == EOF)
- break;
- putc (c, ftable);
- }
-}
-
-static void
-output_program (void)
-{
- int c;
-
- if (!nolinesflag)
- fprintf (ftable, "#line %d \"%s\"\n", lineno, infile);
-
- c = getc (finput);
- while (c != EOF)
- {
- putc (c, ftable);
- c = getc (finput);
- }
+ strcpy (full_skeleton + pkgdatadirlen + 1, skeleton);
+
+ /* Test whether m4sugar.m4 is readable, to check for proper
+ installation. A faulty installation can cause deadlock, so a
+ cheap sanity check is worthwhile. */
+ xfclose (xfopen (full_m4sugar, "r"));
+
+ /* Create an m4 subprocess connected to us via two pipes. */
+
+ if (trace_flag & trace_tools)
+ fprintf (stderr, "running: %s %s - %s %s\n",
+ m4, full_m4sugar, full_m4bison, full_skeleton);
+
+ /* Some future version of GNU M4 (most likely 1.6) may treat the -dV in a
+ position-dependent manner. Keep it as the first argument so that all
+ files are traced.
+
+ See the thread starting at
+ <http://lists.gnu.org/archive/html/bug-bison/2008-07/msg00000.html>
+ for details. */
+ {
+ int i = 0;
+ argv[i++] = m4;
+ argv[i++] = "-I";
+ argv[i++] = pkgdatadir;
+ if (trace_flag & trace_m4)
+ argv[i++] = "-dV";
+ argv[i++] = full_m4sugar;
+ argv[i++] = "-";
+ argv[i++] = full_m4bison;
+ argv[i++] = full_skeleton;
+ argv[i++] = NULL;
+ }
+ /* When POSIXLY_CORRECT is set, some future versions of GNU M4 (most likely
+ 2.0) may drop some of the GNU extensions that Bison's skeletons depend
+ upon. So that the next release of Bison is forward compatible with those
+ future versions of GNU M4, we unset POSIXLY_CORRECT here.
+
+ FIXME: A user might set POSIXLY_CORRECT to affect processes run from
+ macros like m4_syscmd in a custom skeleton. For now, Bison makes no
+ promises about the behavior of custom skeletons, so this scenario is not a
+ concern. However, we eventually want to eliminate this shortcoming. The
+ next release of GNU M4 (1.4.12 or 1.6) will accept the -g command-line
+ option as a no-op, and later releases will accept it to indicate that
+ POSIXLY_CORRECT should be ignored. Once the GNU M4 versions that accept
+ -g are pervasive, Bison should use -g instead of unsetting
+ POSIXLY_CORRECT.
+
+ See the thread starting at
+ <http://lists.gnu.org/archive/html/bug-bison/2008-07/msg00000.html>
+ for details. */
+ unsetenv ("POSIXLY_CORRECT");
+ init_subpipe ();
+ pid = create_subpipe (argv, filter_fd);
+ free (full_m4sugar);
+ free (full_m4bison);
+ free (full_skeleton);
+
+ if (trace_flag & trace_muscles)
+ muscles_output (stderr);
+ {
+ FILE *out = fdopen (filter_fd[0], "w");
+ if (! out)
+ error (EXIT_FAILURE, get_errno (),
+ "fdopen");
+ muscles_output (out);
+ xfclose (out);
+ }
+
+ /* Read and process m4's output. */
+ timevar_push (TV_M4);
+ end_of_output_subpipe (pid, filter_fd);
+ in = fdopen (filter_fd[1], "r");
+ if (! in)
+ error (EXIT_FAILURE, get_errno (),
+ "fdopen");
+ scan_skel (in);
+ xfclose (in);
+ reap_subpipe (pid, m4);
+ timevar_pop (TV_M4);
projects / bison.git / blobdiff