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Diffstat (limited to 'src/m4.c')
| -rw-r--r-- | src/m4.c | 690 |
1 files changed, 690 insertions, 0 deletions
diff --git a/src/m4.c b/src/m4.c new file mode 100644 index 0000000..3e56e9d --- /dev/null +++ b/src/m4.c @@ -0,0 +1,690 @@ +/* GNU m4 -- A simple macro processor + + Copyright (C) 1989-1994, 2004-2013 Free Software Foundation, Inc. + + This file is part of GNU M4. + + GNU M4 is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + GNU M4 is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "m4.h" + +#include <getopt.h> +#include <limits.h> +#include <signal.h> + +#include "c-stack.h" +#include "ignore-value.h" +#include "progname.h" +#include "version-etc.h" + +#ifdef DEBUG_STKOVF +# include "assert.h" +#endif + +#define AUTHORS "Rene' Seindal" + +static void usage (int) M4_GNUC_NORETURN; + +/* Enable sync output for /lib/cpp (-s). */ +int sync_output = 0; + +/* Debug (-d[flags]). */ +int debug_level = 0; + +/* Hash table size (should be a prime) (-Hsize). */ +size_t hash_table_size = HASHMAX; + +/* Disable GNU extensions (-G). */ +int no_gnu_extensions = 0; + +/* Prefix all builtin functions by `m4_'. */ +int prefix_all_builtins = 0; + +/* Max length of arguments in trace output (-lsize). */ +int max_debug_argument_length = 0; + +/* Suppress warnings about missing arguments. */ +int suppress_warnings = 0; + +/* If true, then warnings affect exit status. */ +static bool fatal_warnings = false; + +/* If not zero, then value of exit status for warning diagnostics. */ +int warning_status = 0; + +/* Artificial limit for expansion_level in macro.c. */ +int nesting_limit = 1024; + +#ifdef ENABLE_CHANGEWORD +/* User provided regexp for describing m4 words. */ +const char *user_word_regexp = ""; +#endif + +/* Global catchall for any errors that should affect final error status, but + where we try to continue execution in the meantime. */ +int retcode; + +struct macro_definition +{ + struct macro_definition *next; + int code; /* D, U, s, t, '\1', or DEBUGFILE_OPTION. */ + const char *arg; +}; +typedef struct macro_definition macro_definition; + +/* Error handling functions. */ + +/*-----------------------. +| Wrapper around error. | +`-----------------------*/ + +void +m4_error (int status, int errnum, const char *format, ...) +{ + va_list args; + va_start (args, format); + verror_at_line (status, errnum, current_line ? current_file : NULL, + current_line, format, args); + if (fatal_warnings && ! retcode) + retcode = EXIT_FAILURE; + va_end (args); +} + +/*-------------------------------. +| Wrapper around error_at_line. | +`-------------------------------*/ + +void +m4_error_at_line (int status, int errnum, const char *file, int line, + const char *format, ...) +{ + va_list args; + va_start (args, format); + verror_at_line (status, errnum, line ? file : NULL, line, format, args); + if (fatal_warnings && ! retcode) + retcode = EXIT_FAILURE; + va_end (args); +} + +#ifndef SIGBUS +# define SIGBUS SIGILL +#endif + +#ifndef NSIG +# ifndef MAX +# define MAX(a,b) ((a) < (b) ? (b) : (a)) +# endif +# define NSIG (MAX (SIGABRT, MAX (SIGILL, MAX (SIGFPE, \ + MAX (SIGSEGV, SIGBUS)))) + 1) +#endif + +/* Pre-translated messages for program errors. Do not translate in + the signal handler, since gettext and strsignal are not + async-signal-safe. */ +static const char * volatile program_error_message; +static const char * volatile signal_message[NSIG]; + +/* Print a nicer message about any programmer errors, then exit. This + must be aysnc-signal safe, since it is executed as a signal + handler. If SIGNO is zero, this represents a stack overflow; in + that case, we return to allow c_stack_action to handle things. */ +static void M4_GNUC_PURE +fault_handler (int signo) +{ + if (signo) + { + /* POSIX states that reading static memory is, in general, not + async-safe. However, the static variables that we read are + never modified once this handler is installed, so this + particular usage is safe. And it seems an oversight that + POSIX claims strlen is not async-safe. Ignore write + failures, since we will exit with non-zero status anyway. */ +#define WRITE(f, b, l) ignore_value (write (f, b, l)) + WRITE (STDERR_FILENO, program_name, strlen (program_name)); + WRITE (STDERR_FILENO, ": ", 2); + WRITE (STDERR_FILENO, program_error_message, + strlen (program_error_message)); + if (signal_message[signo]) + { + WRITE (STDERR_FILENO, ": ", 2); + WRITE (STDERR_FILENO, signal_message[signo], + strlen (signal_message[signo])); + } + WRITE (STDERR_FILENO, "\n", 1); +#undef WRITE + _exit (EXIT_INTERNAL_ERROR); + } +} + + +/*---------------------------------------------. +| Print a usage message and exit with STATUS. | +`---------------------------------------------*/ + +static void +usage (int status) +{ + if (status != EXIT_SUCCESS) + xfprintf (stderr, "Try `%s --help' for more information.\n", program_name); + else + { + xprintf ("Usage: %s [OPTION]... [FILE]...\n", program_name); + fputs ("\ +Process macros in FILEs. If no FILE or if FILE is `-', standard input\n\ +is read.\n\ +", stdout); + fputs ("\ +\n\ +Mandatory or optional arguments to long options are mandatory or optional\n\ +for short options too.\n\ +\n\ +Operation modes:\n\ + --help display this help and exit\n\ + --version output version information and exit\n\ +", stdout); + xprintf ("\ + -E, --fatal-warnings once: warnings become errors, twice: stop\n\ + execution at first error\n\ + -i, --interactive unbuffer output, ignore interrupts\n\ + -P, --prefix-builtins force a `m4_' prefix to all builtins\n\ + -Q, --quiet, --silent suppress some warnings for builtins\n\ + --warn-macro-sequence[=REGEXP]\n\ + warn if macro definition matches REGEXP,\n\ + default %s\n\ +", DEFAULT_MACRO_SEQUENCE); +#ifdef ENABLE_CHANGEWORD + fputs ("\ + -W, --word-regexp=REGEXP use REGEXP for macro name syntax\n\ +", stdout); +#endif + fputs ("\ +\n\ +Preprocessor features:\n\ + -D, --define=NAME[=VALUE] define NAME as having VALUE, or empty\n\ + -I, --include=DIRECTORY append DIRECTORY to include path\n\ + -s, --synclines generate `#line NUM \"FILE\"' lines\n\ + -U, --undefine=NAME undefine NAME\n\ +", stdout); + puts (""); + xprintf (_("\ +Limits control:\n\ + -g, --gnu override -G to re-enable GNU extensions\n\ + -G, --traditional suppress all GNU extensions\n\ + -H, --hashsize=PRIME set symbol lookup hash table size [509]\n\ + -L, --nesting-limit=NUMBER change nesting limit, 0 for unlimited [%d]\n\ +"), nesting_limit); + puts (""); + fputs ("\ +Frozen state files:\n\ + -F, --freeze-state=FILE produce a frozen state on FILE at end\n\ + -R, --reload-state=FILE reload a frozen state from FILE at start\n\ +", stdout); + fputs ("\ +\n\ +Debugging:\n\ + -d, --debug[=FLAGS] set debug level (no FLAGS implies `aeq')\n\ + --debugfile[=FILE] redirect debug and trace output to FILE\n\ + (default stderr, discard if empty string)\n\ + -l, --arglength=NUM restrict macro tracing size\n\ + -t, --trace=NAME trace NAME when it is defined\n\ +", stdout); + fputs ("\ +\n\ +FLAGS is any of:\n\ + a show actual arguments\n\ + c show before collect, after collect and after call\n\ + e show expansion\n\ + f say current input file name\n\ + i show changes in input files\n\ + l say current input line number\n\ + p show results of path searches\n\ + q quote values as necessary, with a or e flag\n\ + t trace for all macro calls, not only traceon'ed\n\ + x add a unique macro call id, useful with c flag\n\ + V shorthand for all of the above flags\n\ +", stdout); + fputs ("\ +\n\ +If defined, the environment variable `M4PATH' is a colon-separated list\n\ +of directories included after any specified by `-I'.\n\ +", stdout); + fputs ("\ +\n\ +Exit status is 0 for success, 1 for failure, 63 for frozen file version\n\ +mismatch, or whatever value was passed to the m4exit macro.\n\ +", stdout); + emit_bug_reporting_address (); + } + exit (status); +} + +/*--------------------------------------. +| Decode options and launch execution. | +`--------------------------------------*/ + +/* For long options that have no equivalent short option, use a + non-character as a pseudo short option, starting with CHAR_MAX + 1. */ +enum +{ + DEBUGFILE_OPTION = CHAR_MAX + 1, /* no short opt */ + DIVERSIONS_OPTION, /* not quite -N, because of message */ + WARN_MACRO_SEQUENCE_OPTION, /* no short opt */ + + HELP_OPTION, /* no short opt */ + VERSION_OPTION /* no short opt */ +}; + +static const struct option long_options[] = +{ + {"arglength", required_argument, NULL, 'l'}, + {"debug", optional_argument, NULL, 'd'}, + {"define", required_argument, NULL, 'D'}, + {"error-output", required_argument, NULL, 'o'}, /* FIXME: deprecate in 2.0 */ + {"fatal-warnings", no_argument, NULL, 'E'}, + {"freeze-state", required_argument, NULL, 'F'}, + {"gnu", no_argument, NULL, 'g'}, + {"hashsize", required_argument, NULL, 'H'}, + {"include", required_argument, NULL, 'I'}, + {"interactive", no_argument, NULL, 'i'}, + {"nesting-limit", required_argument, NULL, 'L'}, + {"prefix-builtins", no_argument, NULL, 'P'}, + {"quiet", no_argument, NULL, 'Q'}, + {"reload-state", required_argument, NULL, 'R'}, + {"silent", no_argument, NULL, 'Q'}, + {"synclines", no_argument, NULL, 's'}, + {"trace", required_argument, NULL, 't'}, + {"traditional", no_argument, NULL, 'G'}, + {"undefine", required_argument, NULL, 'U'}, + {"word-regexp", required_argument, NULL, 'W'}, + + {"debugfile", optional_argument, NULL, DEBUGFILE_OPTION}, + {"diversions", required_argument, NULL, DIVERSIONS_OPTION}, + {"warn-macro-sequence", optional_argument, NULL, WARN_MACRO_SEQUENCE_OPTION}, + + {"help", no_argument, NULL, HELP_OPTION}, + {"version", no_argument, NULL, VERSION_OPTION}, + + { NULL, 0, NULL, 0 }, +}; + +/* Process a command line file NAME, and return true only if it was + stdin. */ +static void +process_file (const char *name) +{ + if (STREQ (name, "-")) + { + /* If stdin is a terminal, we want to allow 'm4 - file -' + to read input from stdin twice, like GNU cat. Besides, + there is no point closing stdin before wrapped text, to + minimize bugs in syscmd called from wrapped text. */ + push_file (stdin, "stdin", false); + } + else + { + char *full_name; + FILE *fp = m4_path_search (name, &full_name); + if (fp == NULL) + { + error (0, errno, _("cannot open `%s'"), name); + /* Set the status to EXIT_FAILURE, even though we + continue to process files after a missing file. */ + retcode = EXIT_FAILURE; + return; + } + push_file (fp, full_name, true); + free (full_name); + } + expand_input (); +} + +/* POSIX requires only -D, -U, and -s; and says that the first two + must be recognized when interspersed with file names. Traditional + behavior also handles -s between files. Starting OPTSTRING with + '-' forces getopt_long to hand back file names as arguments to opt + '\1', rather than reordering the command line. */ +#ifdef ENABLE_CHANGEWORD +#define OPTSTRING "-B:D:EF:GH:I:L:N:PQR:S:T:U:W:d::egil:o:st:" +#else +#define OPTSTRING "-B:D:EF:GH:I:L:N:PQR:S:T:U:d::egil:o:st:" +#endif + +int +main (int argc, char *const *argv) +{ + struct sigaction act; + macro_definition *head; /* head of deferred argument list */ + macro_definition *tail; + macro_definition *defn; + int optchar; /* option character */ + + macro_definition *defines; + bool interactive = false; + bool seen_file = false; + const char *debugfile = NULL; + const char *frozen_file_to_read = NULL; + const char *frozen_file_to_write = NULL; + const char *macro_sequence = ""; + + set_program_name (argv[0]); + retcode = EXIT_SUCCESS; + atexit (close_stdin); + + include_init (); + debug_init (); + + /* Stack overflow and program error handling. Ignore failure to + install a handler, since this is merely for improved output on + crash, and we should never crash ;). We install SIGBUS and + SIGSEGV handlers prior to using the c-stack module; depending on + the platform, c-stack will then override none, SIGSEGV, or both + handlers. */ + program_error_message + = xasprintf (_("internal error detected; please report this bug to <%s>"), + PACKAGE_BUGREPORT); + signal_message[SIGSEGV] = xstrdup (strsignal (SIGSEGV)); + signal_message[SIGABRT] = xstrdup (strsignal (SIGABRT)); + signal_message[SIGILL] = xstrdup (strsignal (SIGILL)); + signal_message[SIGFPE] = xstrdup (strsignal (SIGFPE)); + if (SIGBUS != SIGILL && SIGBUS != SIGSEGV) + signal_message[SIGBUS] = xstrdup (strsignal (SIGBUS)); + sigemptyset (&act.sa_mask); + /* One-shot - if we fault while handling a fault, we want to revert + to default signal behavior. */ + act.sa_flags = SA_NODEFER | SA_RESETHAND; + act.sa_handler = fault_handler; + sigaction (SIGSEGV, &act, NULL); + sigaction (SIGABRT, &act, NULL); + sigaction (SIGILL, &act, NULL); + sigaction (SIGFPE, &act, NULL); + sigaction (SIGBUS, &act, NULL); + if (c_stack_action (fault_handler) == 0) + nesting_limit = 0; + +#ifdef DEBUG_STKOVF + /* Make it easier to test our fault handlers. Exporting M4_CRASH=0 + attempts a SIGSEGV, exporting it as 1 attempts an assertion + failure with a fallback to abort. */ + { + char *crash = getenv ("M4_CRASH"); + if (crash) + { + if (!strtol (crash, NULL, 10)) + ++*(int *) 8; + assert (false); + abort (); + } + } +#endif /* DEBUG_STKOVF */ + + /* First, we decode the arguments, to size up tables and stuff. */ + head = tail = NULL; + + while ((optchar = getopt_long (argc, (char **) argv, OPTSTRING, + long_options, NULL)) != -1) + switch (optchar) + { + default: + usage (EXIT_FAILURE); + + case 'B': + case 'S': + case 'T': + /* Compatibility junk: options that other implementations + support, but which we ignore as no-ops and don't list in + --help. */ + error (0, 0, _("warning: `m4 -%c' may be removed in a future release"), + optchar); + break; + + case 'N': + case DIVERSIONS_OPTION: + /* -N became an obsolete no-op in 1.4.x. */ + error (0, 0, _("warning: `m4 %s' is deprecated"), + optchar == 'N' ? "-N" : "--diversions"); + break; + + case 'D': + case 'U': + case 's': + case 't': + case '\1': + case DEBUGFILE_OPTION: + /* Arguments that cannot be handled until later are accumulated. */ + + defn = (macro_definition *) xmalloc (sizeof (macro_definition)); + defn->code = optchar; + defn->arg = optarg; + defn->next = NULL; + + if (head == NULL) + head = defn; + else + tail->next = defn; + tail = defn; + + break; + + case 'E': + if (! fatal_warnings) + fatal_warnings = true; + else + warning_status = EXIT_FAILURE; + break; + + case 'F': + frozen_file_to_write = optarg; + break; + + case 'G': + no_gnu_extensions = 1; + break; + + case 'H': + hash_table_size = strtol (optarg, NULL, 10); + if (hash_table_size == 0) + hash_table_size = HASHMAX; + break; + + case 'I': + add_include_directory (optarg); + break; + + case 'L': + nesting_limit = strtol (optarg, NULL, 10); + break; + + case 'P': + prefix_all_builtins = 1; + break; + + case 'Q': + suppress_warnings = 1; + break; + + case 'R': + frozen_file_to_read = optarg; + break; + +#ifdef ENABLE_CHANGEWORD + case 'W': + user_word_regexp = optarg; + break; +#endif + + case 'd': + debug_level = debug_decode (optarg); + if (debug_level < 0) + { + error (0, 0, _("bad debug flags: `%s'"), optarg); + debug_level = 0; + } + break; + + case 'e': + error (0, 0, _("warning: `m4 -e' is deprecated, use `-i' instead")); + /* fall through */ + case 'i': + interactive = true; + break; + + case 'g': + no_gnu_extensions = 0; + break; + + case 'l': + max_debug_argument_length = strtol (optarg, NULL, 10); + if (max_debug_argument_length <= 0) + max_debug_argument_length = 0; + break; + + case 'o': + /* -o/--error-output are deprecated synonyms of --debugfile, + but don't issue a deprecation warning until autoconf 2.61 + or later is more widely established, as such a warning + would interfere with all earlier versions of autoconf. */ + /* Don't call debug_set_output here, as it has side effects. */ + debugfile = optarg; + break; + + case WARN_MACRO_SEQUENCE_OPTION: + /* Don't call set_macro_sequence here, as it can exit. + --warn-macro-sequence sets optarg to NULL (which uses the + default regexp); --warn-macro-sequence= sets optarg to "" + (which disables these warnings). */ + macro_sequence = optarg; + break; + + case VERSION_OPTION: + version_etc (stdout, PACKAGE, PACKAGE_NAME, VERSION, AUTHORS, NULL); + exit (EXIT_SUCCESS); + break; + + case HELP_OPTION: + usage (EXIT_SUCCESS); + break; + } + + defines = head; + + /* Do the basic initializations. */ + if (debugfile && !debug_set_output (debugfile)) + M4ERROR ((warning_status, errno, "cannot set debug file `%s'", debugfile)); + + input_init (); + output_init (); + symtab_init (); + set_macro_sequence (macro_sequence); + include_env_init (); + + if (frozen_file_to_read) + reload_frozen_state (frozen_file_to_read); + else + builtin_init (); + + /* Interactive mode means unbuffered output, and interrupts ignored. */ + + if (interactive) + { + signal (SIGINT, SIG_IGN); + setbuf (stdout, (char *) NULL); + } + + /* Handle deferred command line macro definitions. Must come after + initialization of the symbol table. */ + + while (defines != NULL) + { + macro_definition *next; + symbol *sym; + + switch (defines->code) + { + case 'D': + { + /* defines->arg is read-only, so we need a copy. */ + char *macro_name = xstrdup (defines->arg); + char *macro_value = strchr (macro_name, '='); + if (macro_value) + *macro_value++ = '\0'; + define_user_macro (macro_name, macro_value, SYMBOL_INSERT); + free (macro_name); + } + break; + + case 'U': + lookup_symbol (defines->arg, SYMBOL_DELETE); + break; + + case 't': + sym = lookup_symbol (defines->arg, SYMBOL_INSERT); + SYMBOL_TRACED (sym) = true; + break; + + case 's': + sync_output = 1; + break; + + case '\1': + seen_file = true; + process_file (defines->arg); + break; + + case DEBUGFILE_OPTION: + if (!debug_set_output (defines->arg)) + M4ERROR ((warning_status, errno, "cannot set debug file `%s'", + debugfile ? debugfile : _("stderr"))); + break; + + default: + M4ERROR ((0, 0, "INTERNAL ERROR: bad code in deferred arguments")); + abort (); + } + + next = defines->next; + free (defines); + defines = next; + } + + /* Handle remaining input files. Each file is pushed on the input, + and the input read. Wrapup text is handled separately later. */ + + if (optind == argc && !seen_file) + process_file ("-"); + else + for (; optind < argc; optind++) + process_file (argv[optind]); + + /* Now handle wrapup text. */ + + while (pop_wrapup ()) + expand_input (); + + /* Change debug stream back to stderr, to force flushing the debug + stream and detect any errors it might have encountered. The + three standard streams are closed by close_stdin. */ + debug_set_output (NULL); + + if (frozen_file_to_write) + produce_frozen_state (frozen_file_to_write); + else + { + make_diversion (0); + undivert_all (); + } + output_exit (); + free_macro_sequence (); + exit (retcode); +} |