move flex program sources into src/ directory

The *.[chly] sources are now in the src directory. This implies a
bunch of changes in Makefile.am and friends to account for the new
location. The .gitignore files are now more local to places where various object files and generated source files occur.

1 files changed, 444 insertions, 0 deletions

diff --git a/src/filter.c b/src/filter.c
new file mode 100644
index 0000000..c82f7f8
--- /dev/null
+++ b/src/filter.c
@@ -0,0 +1,444 @@
+/* filter - postprocessing of flex output through filters */
+
+/*  This file is part of flex. */
+
+/*  Redistribution and use in source and binary forms, with or without */
+/*  modification, are permitted provided that the following conditions */
+/*  are met: */
+
+/*  1. Redistributions of source code must retain the above copyright */
+/*     notice, this list of conditions and the following disclaimer. */
+/*  2. Redistributions in binary form must reproduce the above copyright */
+/*     notice, this list of conditions and the following disclaimer in the */
+/*     documentation and/or other materials provided with the distribution. */
+
+/*  Neither the name of the University nor the names of its contributors */
+/*  may be used to endorse or promote products derived from this software */
+/*  without specific prior written permission. */
+
+/*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
+/*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
+/*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
+/*  PURPOSE. */
+
+#include "flexdef.h"
+static const char * check_4_gnu_m4 =
+    "m4_dnl ifdef(`__gnu__', ,"
+    "`errprint(Flex requires GNU M4. Set the PATH or set the M4 environment variable to its path name.)"
+    " m4exit(2)')\n";
+
+
+/** global chain. */
+struct filter *output_chain = NULL;
+
+/* Allocate and initialize an external filter.
+ * @param chain the current chain or NULL for new chain
+ * @param cmd the command to execute.
+ * @param ... a NULL terminated list of (const char*) arguments to command,
+ *            not including argv[0].
+ * @return newest filter in chain
+ */
+struct filter *filter_create_ext (struct filter *chain, const char *cmd,
+				  ...)
+{
+	struct filter *f;
+	int     max_args;
+	const char *s;
+	va_list ap;
+
+	/* allocate and initialize new filter */
+	f = (struct filter *) flex_alloc (sizeof (struct filter));
+	if (!f)
+		flexerror (_("flex_alloc failed (f) in filter_create_ext"));
+	memset (f, 0, sizeof (*f));
+	f->filter_func = NULL;
+	f->extra = NULL;
+	f->next = NULL;
+	f->argc = 0;
+
+	if (chain != NULL) {
+		/* append f to end of chain */
+		while (chain->next)
+			chain = chain->next;
+		chain->next = f;
+	}
+
+
+	/* allocate argv, and populate it with the argument list. */
+	max_args = 8;
+	f->argv =
+		(const char **) flex_alloc (sizeof (char *) *
+					    (max_args + 1));
+	if (!f->argv)
+		flexerror (_("flex_alloc failed (f->argv) in filter_create_ext"));
+	f->argv[f->argc++] = cmd;
+
+	va_start (ap, cmd);
+	while ((s = va_arg (ap, const char *)) != NULL) {
+		if (f->argc >= max_args) {
+			max_args += 8;
+			f->argv =
+				(const char **) flex_realloc (f->argv,
+							      sizeof (char
+								      *) *
+							      (max_args +
+							       1));
+		}
+		f->argv[f->argc++] = s;
+	}
+	f->argv[f->argc] = NULL;
+
+	va_end (ap);
+	return f;
+}
+
+/* Allocate and initialize an internal filter.
+ * @param chain the current chain or NULL for new chain
+ * @param filter_func The function that will perform the filtering.
+ *        filter_func should return 0 if successful, and -1
+ *        if an error occurs -- or it can simply exit().
+ * @param extra optional user-defined data to pass to the filter.
+ * @return newest filter in chain
+ */
+struct filter *filter_create_int (struct filter *chain,
+				  int (*filter_func) (struct filter *),
+				  void *extra)
+{
+	struct filter *f;
+
+	/* allocate and initialize new filter */
+	f = (struct filter *) flex_alloc (sizeof (struct filter));
+	if (!f)
+		flexerror (_("flex_alloc failed in filter_create_int"));
+	memset (f, 0, sizeof (*f));
+	f->next = NULL;
+	f->argc = 0;
+	f->argv = NULL;
+
+	f->filter_func = filter_func;
+	f->extra = extra;
+
+	if (chain != NULL) {
+		/* append f to end of chain */
+		while (chain->next)
+			chain = chain->next;
+		chain->next = f;
+	}
+
+	return f;
+}
+
+/** Fork and exec entire filter chain.
+ *  @param chain The head of the chain.
+ *  @return true on success.
+ */
+bool filter_apply_chain (struct filter * chain)
+{
+	int     pid, pipes[2];
+	int     r;
+	const int readsz = 512;
+	char   *buf;
+
+
+	/* Tricky recursion, since we want to begin the chain
+	 * at the END. Why? Because we need all the forked processes
+	 * to be children of the main flex process.
+	 */
+	if (chain)
+		filter_apply_chain (chain->next);
+	else
+		return true;
+
+	/* Now we are the right-most unprocessed link in the chain.
+	 */
+
+	fflush (stdout);
+	fflush (stderr);
+
+
+	if (pipe (pipes) == -1)
+		flexerror (_("pipe failed"));
+
+	if ((pid = fork ()) == -1)
+		flexerror (_("fork failed"));
+
+	if (pid == 0) {
+		/* child */
+
+        /* We need stdin (the FILE* stdin) to connect to this new pipe.
+         * There is no portable way to set stdin to a new file descriptor,
+         * as stdin is not an lvalue on some systems (BSD).
+         * So we dup the new pipe onto the stdin descriptor and use a no-op fseek
+         * to sync the stream. This is a Hail Mary situation. It seems to work.
+         */
+		close (pipes[1]);
+clearerr(stdin);
+		if (dup2 (pipes[0], fileno (stdin)) == -1)
+			flexfatal (_("dup2(pipes[0],0)"));
+		close (pipes[0]);
+        fseek (stdin, 0, SEEK_CUR);
+
+		/* run as a filter, either internally or by exec */
+		if (chain->filter_func) {
+			int     r;
+
+			if ((r = chain->filter_func (chain)) == -1)
+				flexfatal (_("filter_func failed"));
+			exit (0);
+		}
+		else {
+			execvp (chain->argv[0],
+				(char **const) (chain->argv));
+            lerrsf_fatal ( _("exec of %s failed"),
+                    chain->argv[0]);
+		}
+
+		exit (1);
+	}
+
+	/* Parent */
+	close (pipes[0]);
+	if (dup2 (pipes[1], fileno (stdout)) == -1)
+		flexfatal (_("dup2(pipes[1],1)"));
+	close (pipes[1]);
+    fseek (stdout, 0, SEEK_CUR);
+
+	return true;
+}
+
+/** Truncate the chain to max_len number of filters.
+ * @param chain the current chain.
+ * @param max_len the maximum length of the chain.
+ * @return the resulting length of the chain.
+ */
+int filter_truncate (struct filter *chain, int max_len)
+{
+	int     len = 1;
+
+	if (!chain)
+		return 0;
+
+	while (chain->next && len < max_len) {
+		chain = chain->next;
+		++len;
+	}
+
+	chain->next = NULL;
+	return len;
+}
+
+/** Splits the chain in order to write to a header file.
+ *  Similar in spirit to the 'tee' program.
+ *  The header file name is in extra.
+ *  @return 0 (zero) on success, and -1 on failure.
+ */
+int filter_tee_header (struct filter *chain)
+{
+	/* This function reads from stdin and writes to both the C file and the
+	 * header file at the same time.
+	 */
+
+	const int readsz = 512;
+	char   *buf;
+	int     to_cfd = -1;
+	FILE   *to_c = NULL, *to_h = NULL;
+	bool    write_header;
+
+	write_header = (chain->extra != NULL);
+
+	/* Store a copy of the stdout pipe, which is already piped to C file
+	 * through the running chain. Then create a new pipe to the H file as
+	 * stdout, and fork the rest of the chain again.
+	 */
+
+	if ((to_cfd = dup (1)) == -1)
+		flexfatal (_("dup(1) failed"));
+	to_c = fdopen (to_cfd, "w");
+
+	if (write_header) {
+		if (freopen ((char *) chain->extra, "w", stdout) == NULL)
+			flexfatal (_("freopen(headerfilename) failed"));
+
+		filter_apply_chain (chain->next);
+		to_h = stdout;
+	}
+
+	/* Now to_c is a pipe to the C branch, and to_h is a pipe to the H branch.
+	 */
+
+	if (write_header) {
+        fputs (check_4_gnu_m4, to_h);
+		fputs ("m4_changecom`'m4_dnl\n", to_h);
+		fputs ("m4_changequote`'m4_dnl\n", to_h);
+		fputs ("m4_changequote([[,]])[[]]m4_dnl\n", to_h);
+	    fputs ("m4_define([[M4_YY_NOOP]])[[]]m4_dnl\n", to_h);
+		fputs ("m4_define( [[M4_YY_IN_HEADER]],[[]])m4_dnl\n",
+		       to_h);
+		fprintf (to_h, "#ifndef %sHEADER_H\n", prefix);
+		fprintf (to_h, "#define %sHEADER_H 1\n", prefix);
+		fprintf (to_h, "#define %sIN_HEADER 1\n\n", prefix);
+		fprintf (to_h,
+			 "m4_define( [[M4_YY_OUTFILE_NAME]],[[%s]])m4_dnl\n",
+			 headerfilename ? headerfilename : "<stdout>");
+
+	}
+
+    fputs (check_4_gnu_m4, to_c);
+	fputs ("m4_changecom`'m4_dnl\n", to_c);
+	fputs ("m4_changequote`'m4_dnl\n", to_c);
+	fputs ("m4_changequote([[,]])[[]]m4_dnl\n", to_c);
+	fputs ("m4_define([[M4_YY_NOOP]])[[]]m4_dnl\n", to_c);
+	fprintf (to_c, "m4_define( [[M4_YY_OUTFILE_NAME]],[[%s]])m4_dnl\n",
+		 outfilename ? outfilename : "<stdout>");
+
+	buf = (char *) flex_alloc (readsz);
+	if (!buf)
+		flexerror (_("flex_alloc failed in filter_tee_header"));
+	while (fgets (buf, readsz, stdin)) {
+		fputs (buf, to_c);
+		if (write_header)
+			fputs (buf, to_h);
+	}
+
+	if (write_header) {
+		fprintf (to_h, "\n");
+
+		/* write a fake line number. It will get fixed by the linedir filter. */
+		fprintf (to_h, "#line 4000 \"M4_YY_OUTFILE_NAME\"\n");
+
+		fprintf (to_h, "#undef %sIN_HEADER\n", prefix);
+		fprintf (to_h, "#endif /* %sHEADER_H */\n", prefix);
+		fputs ("m4_undefine( [[M4_YY_IN_HEADER]])m4_dnl\n", to_h);
+
+		fflush (to_h);
+		if (ferror (to_h))
+			lerrsf (_("error writing output file %s"),
+				(char *) chain->extra);
+
+		else if (fclose (to_h))
+			lerrsf (_("error closing output file %s"),
+				(char *) chain->extra);
+	}
+
+	fflush (to_c);
+	if (ferror (to_c))
+		lerrsf (_("error writing output file %s"),
+			outfilename ? outfilename : "<stdout>");
+
+	else if (fclose (to_c))
+		lerrsf (_("error closing output file %s"),
+			outfilename ? outfilename : "<stdout>");
+
+	while (wait (0) > 0) ;
+
+	exit (0);
+	return 0;
+}
+
+/** Adjust the line numbers in the #line directives of the generated scanner.
+ * After the m4 expansion, the line numbers are incorrect since the m4 macros
+ * can add or remove lines.  This only adjusts line numbers for generated code,
+ * not user code. This also happens to be a good place to squeeze multiple
+ * blank lines into a single blank line.
+ */
+int filter_fix_linedirs (struct filter *chain)
+{
+	char   *buf;
+	const int readsz = 512;
+	int     lineno = 1;
+	bool    in_gen = true;	/* in generated code */
+	bool    last_was_blank = false;
+
+	if (!chain)
+		return 0;
+
+	buf = (char *) flex_alloc (readsz);
+	if (!buf)
+		flexerror (_("flex_alloc failed in filter_fix_linedirs"));
+
+	while (fgets (buf, readsz, stdin)) {
+
+		regmatch_t m[10];
+
+		/* Check for #line directive. */
+		if (buf[0] == '#'
+			&& regexec (&regex_linedir, buf, 3, m, 0) == 0) {
+
+			int     num;
+			char   *fname;
+
+			/* extract the line number and filename */
+			num = regmatch_strtol (&m[1], buf, NULL, 0);
+			fname = regmatch_dup (&m[2], buf);
+
+			if (strcmp (fname,
+				outfilename ? outfilename : "<stdout>")
+					== 0
+			 || strcmp (fname,
+			 	headerfilename ? headerfilename : "<stdout>")
+					== 0) {
+
+				char    *s1, *s2;
+				char	filename[MAXLINE];
+
+				s1 = fname;
+				s2 = filename;
+
+				while ((s2 - filename) < (MAXLINE - 1) && *s1) {
+					/* Escape the backslash */
+					if (*s1 == '\\')
+						*s2++ = '\\';
+					/* Escape the double quote */
+					if (*s1 == '\"')
+						*s2++ = '\\';
+					/* Copy the character as usual */
+					*s2++ = *s1++;
+				}
+
+				*s2 = '\0';
+
+				/* Adjust the line directives. */
+				in_gen = true;
+				snprintf (buf, readsz, "#line %d \"%s\"\n",
+					  lineno + 1, filename);
+			}
+			else {
+				/* it's a #line directive for code we didn't write */
+				in_gen = false;
+			}
+
+			free (fname);
+			last_was_blank = false;
+		}
+
+		/* squeeze blank lines from generated code */
+		else if (in_gen
+			 && regexec (&regex_blank_line, buf, 0, NULL,
+				     0) == 0) {
+			if (last_was_blank)
+				continue;
+			else
+				last_was_blank = true;
+		}
+
+		else {
+			/* it's a line of normal, non-empty code. */
+			last_was_blank = false;
+		}
+
+		fputs (buf, stdout);
+		lineno++;
+	}
+	fflush (stdout);
+	if (ferror (stdout))
+		lerrsf (_("error writing output file %s"),
+			outfilename ? outfilename : "<stdout>");
+
+	else if (fclose (stdout))
+		lerrsf (_("error closing output file %s"),
+			outfilename ? outfilename : "<stdout>");
+
+	return 0;
+}
+
+/* vim:set expandtab cindent tabstop=4 softtabstop=4 shiftwidth=4 textwidth=0: */