diff options
Diffstat (limited to 'filter.c')
| -rw-r--r-- | filter.c | 444 |
1 files changed, 0 insertions, 444 deletions
diff --git a/filter.c b/filter.c deleted file mode 100644 index c82f7f8..0000000 --- a/filter.c +++ /dev/null @@ -1,444 +0,0 @@ -/* 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 (®ex_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 (®ex_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: */ |