- /* Store the definition of all the muscles. */
- const char *tempdir = getenv ("TMPDIR");
- char *tempfile = NULL;
- FILE *out = NULL;
- int fd;
-
- if (tempdir == NULL)
- tempdir = DEFAULT_TMPDIR;
- tempfile = xmalloc (strlen (tempdir) + 11);
- sprintf (tempfile, "%s/bsnXXXXXX", tempdir);
- fd = mkstemp (tempfile);
- if (fd == -1)
- error (EXIT_FAILURE, errno, "%s", tempfile);
-
- out = fdopen (fd, "w");
- if (out == NULL)
- error (EXIT_FAILURE, errno, "%s", tempfile);
-
- /* There are no comments, especially not `#': we do want M4 expansion
- after `#': think of CPP macros! */
- fputs ("m4_changecom()\n", out);
- fputs ("m4_init()\n", out);
-
- user_actions_output (out);
- merger_output (out);
- token_definitions_output (out);
- symbol_destructors_output (out);
- symbol_printers_output (out);
+ int filter_fd[2];
+ pid_t pid;
+
+ /* Compute the names of the package data dir and skeleton files. */
+ char const *m4 = (m4 = getenv ("M4")) ? m4 : M4;
+ char const *datadir = pkgdatadir ();
+ char *m4sugar = xconcatenated_filename (datadir, "m4sugar/m4sugar.m4", NULL);
+ char *m4bison = xconcatenated_filename (datadir, "bison.m4", NULL);
+ char *skel = (IS_PATH_WITH_DIR (skeleton)
+ ? xstrdup (skeleton)
+ : xconcatenated_filename (datadir, skeleton, NULL));
+
+ /* 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 (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, m4sugar, m4bison, skel);
+
+ /* 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. */
+ {
+ char const *argv[10];
+ int i = 0;
+ argv[i++] = m4;
+
+ /* When POSIXLY_CORRECT is set, GNU M4 1.6 and later disable GNU
+ extensions, which Bison's skeletons depend on. With older M4,
+ it has no effect. M4 1.4.12 added a -g/--gnu command-line
+ option to make it explicit that a program wants GNU M4
+ extensions even when POSIXLY_CORRECT is set.
+
+ See the thread starting at
+ <http://lists.gnu.org/archive/html/bug-bison/2008-07/msg00000.html>
+ for details. */
+ if (*M4_GNU_OPTION)
+ argv[i++] = M4_GNU_OPTION;
+
+ argv[i++] = "-I";
+ argv[i++] = datadir;
+ if (trace_flag & trace_m4)
+ argv[i++] = "-dV";
+ argv[i++] = m4sugar;
+ argv[i++] = "-";
+ argv[i++] = m4bison;
+ argv[i++] = skel;
+ argv[i++] = NULL;
+ aver (i <= ARRAY_CARDINALITY (argv));
+
+ /* The ugly cast is because gnulib gets the const-ness wrong. */
+ pid = create_pipe_bidi ("m4", m4, (char **)(void*)argv, false, true,
+ true, filter_fd);
+ }
projects / bison.git / blobdiff