+}
+\f
+/*---------------------------.
+| Call the skeleton parser. |
+`---------------------------*/
+
+static void
+output_skeleton (void)
+{
+ FILE *in;
+ int filter_fd[2];
+ char const *argv[10];
+ pid_t pid;
+
+ /* Compute the names of the package data dir and skeleton files. */
+ char const m4sugar[] = "m4sugar/m4sugar.m4";
+ char const m4bison[] = "bison.m4";
+ char *full_m4sugar;
+ char *full_m4bison;
+ char *full_skeleton;
+ char const *p;
+ char const *m4 = (p = getenv ("M4")) ? p : M4;
+ char const *pkgdatadir = compute_pkgdatadir ();
+ size_t skeleton_size = strlen (skeleton) + 1;
+ size_t pkgdatadirlen = strlen (pkgdatadir);
+ while (pkgdatadirlen && pkgdatadir[pkgdatadirlen - 1] == '/')
+ pkgdatadirlen--;
+ full_skeleton = xmalloc (pkgdatadirlen + 1
+ + (skeleton_size < sizeof m4sugar
+ ? sizeof m4sugar : skeleton_size));
+ strncpy (full_skeleton, pkgdatadir, pkgdatadirlen);
+ full_skeleton[pkgdatadirlen] = '/';
+ strcpy (full_skeleton + pkgdatadirlen + 1, m4sugar);
+ full_m4sugar = xstrdup (full_skeleton);
+ strcpy (full_skeleton + pkgdatadirlen + 1, m4bison);
+ full_m4bison = xstrdup (full_skeleton);
+ if (mbschr (skeleton, '/'))
+ strcpy (full_skeleton, skeleton);
+ else
+ 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;
+
+ /* 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++] = 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;
+ 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);
+ free (full_m4sugar);
+ free (full_m4bison);
+ free (full_skeleton);
projects / bison.git / blobdiff