diff options
Diffstat (limited to 'src/lua.c')
| -rw-r--r-- | src/lua.c | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/src/lua.c b/src/lua.c new file mode 100644 index 0000000..3a46609 --- /dev/null +++ b/src/lua.c @@ -0,0 +1,392 @@ +/* +** $Id: lua.c,v 1.160.1.2 2007/12/28 15:32:23 roberto Exp $ +** Lua stand-alone interpreter +** See Copyright Notice in lua.h +*/ + + +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#define lua_c + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + + +static lua_State *globalL = NULL; + +static const char *progname = LUA_PROGNAME; + + + +static void lstop (lua_State *L, lua_Debug *ar) { + (void)ar; /* unused arg. */ + lua_sethook(L, NULL, 0, 0); + luaL_error(L, "interrupted!"); +} + + +static void laction (int i) { + signal(i, SIG_DFL); /* if another SIGINT happens before lstop, + terminate process (default action) */ + lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1); +} + + +static void print_usage (void) { + fprintf(stderr, + "usage: %s [options] [script [args]].\n" + "Available options are:\n" + " -e stat execute string " LUA_QL("stat") "\n" + " -l name require library " LUA_QL("name") "\n" + " -i enter interactive mode after executing " LUA_QL("script") "\n" + " -v show version information\n" + " -- stop handling options\n" + " - execute stdin and stop handling options\n" + , + progname); + fflush(stderr); +} + + +static void l_message (const char *pname, const char *msg) { + if (pname) fprintf(stderr, "%s: ", pname); + fprintf(stderr, "%s\n", msg); + fflush(stderr); +} + + +static int report (lua_State *L, int status) { + if (status && !lua_isnil(L, -1)) { + const char *msg = lua_tostring(L, -1); + if (msg == NULL) msg = "(error object is not a string)"; + l_message(progname, msg); + lua_pop(L, 1); + } + return status; +} + + +static int traceback (lua_State *L) { + if (!lua_isstring(L, 1)) /* 'message' not a string? */ + return 1; /* keep it intact */ + lua_getfield(L, LUA_GLOBALSINDEX, "debug"); + if (!lua_istable(L, -1)) { + lua_pop(L, 1); + return 1; + } + lua_getfield(L, -1, "traceback"); + if (!lua_isfunction(L, -1)) { + lua_pop(L, 2); + return 1; + } + lua_pushvalue(L, 1); /* pass error message */ + lua_pushinteger(L, 2); /* skip this function and traceback */ + lua_call(L, 2, 1); /* call debug.traceback */ + return 1; +} + + +static int docall (lua_State *L, int narg, int clear) { + int status; + int base = lua_gettop(L) - narg; /* function index */ + lua_pushcfunction(L, traceback); /* push traceback function */ + lua_insert(L, base); /* put it under chunk and args */ + signal(SIGINT, laction); + status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base); + signal(SIGINT, SIG_DFL); + lua_remove(L, base); /* remove traceback function */ + /* force a complete garbage collection in case of errors */ + if (status != 0) lua_gc(L, LUA_GCCOLLECT, 0); + return status; +} + + +static void print_version (void) { + l_message(NULL, LUA_RELEASE " " LUA_COPYRIGHT); +} + + +static int getargs (lua_State *L, char **argv, int n) { + int narg; + int i; + int argc = 0; + while (argv[argc]) argc++; /* count total number of arguments */ + narg = argc - (n + 1); /* number of arguments to the script */ + luaL_checkstack(L, narg + 3, "too many arguments to script"); + for (i=n+1; i < argc; i++) + lua_pushstring(L, argv[i]); + lua_createtable(L, narg, n + 1); + for (i=0; i < argc; i++) { + lua_pushstring(L, argv[i]); + lua_rawseti(L, -2, i - n); + } + return narg; +} + + +static int dofile (lua_State *L, const char *name) { + int status = luaL_loadfile(L, name) || docall(L, 0, 1); + return report(L, status); +} + + +static int dostring (lua_State *L, const char *s, const char *name) { + int status = luaL_loadbuffer(L, s, strlen(s), name) || docall(L, 0, 1); + return report(L, status); +} + + +static int dolibrary (lua_State *L, const char *name) { + lua_getglobal(L, "require"); + lua_pushstring(L, name); + return report(L, docall(L, 1, 1)); +} + + +static const char *get_prompt (lua_State *L, int firstline) { + const char *p; + lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2"); + p = lua_tostring(L, -1); + if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2); + lua_pop(L, 1); /* remove global */ + return p; +} + + +static int incomplete (lua_State *L, int status) { + if (status == LUA_ERRSYNTAX) { + size_t lmsg; + const char *msg = lua_tolstring(L, -1, &lmsg); + const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1); + if (strstr(msg, LUA_QL("<eof>")) == tp) { + lua_pop(L, 1); + return 1; + } + } + return 0; /* else... */ +} + + +static int pushline (lua_State *L, int firstline) { + char buffer[LUA_MAXINPUT]; + char *b = buffer; + size_t l; + const char *prmt = get_prompt(L, firstline); + if (lua_readline(L, b, prmt) == 0) + return 0; /* no input */ + l = strlen(b); + if (l > 0 && b[l-1] == '\n') /* line ends with newline? */ + b[l-1] = '\0'; /* remove it */ + if (firstline && b[0] == '=') /* first line starts with `=' ? */ + lua_pushfstring(L, "return %s", b+1); /* change it to `return' */ + else + lua_pushstring(L, b); + lua_freeline(L, b); + return 1; +} + + +static int loadline (lua_State *L) { + int status; + lua_settop(L, 0); + if (!pushline(L, 1)) + return -1; /* no input */ + for (;;) { /* repeat until gets a complete line */ + status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=stdin"); + if (!incomplete(L, status)) break; /* cannot try to add lines? */ + if (!pushline(L, 0)) /* no more input? */ + return -1; + lua_pushliteral(L, "\n"); /* add a new line... */ + lua_insert(L, -2); /* ...between the two lines */ + lua_concat(L, 3); /* join them */ + } + lua_saveline(L, 1); + lua_remove(L, 1); /* remove line */ + return status; +} + + +static void dotty (lua_State *L) { + int status; + const char *oldprogname = progname; + progname = NULL; + while ((status = loadline(L)) != -1) { + if (status == 0) status = docall(L, 0, 0); + report(L, status); + if (status == 0 && lua_gettop(L) > 0) { /* any result to print? */ + lua_getglobal(L, "print"); + lua_insert(L, 1); + if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0) + l_message(progname, lua_pushfstring(L, + "error calling " LUA_QL("print") " (%s)", + lua_tostring(L, -1))); + } + } + lua_settop(L, 0); /* clear stack */ + fputs("\n", stdout); + fflush(stdout); + progname = oldprogname; +} + + +static int handle_script (lua_State *L, char **argv, int n) { + int status; + const char *fname; + int narg = getargs(L, argv, n); /* collect arguments */ + lua_setglobal(L, "arg"); + fname = argv[n]; + if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0) + fname = NULL; /* stdin */ + status = luaL_loadfile(L, fname); + lua_insert(L, -(narg+1)); + if (status == 0) + status = docall(L, narg, 0); + else + lua_pop(L, narg); + return report(L, status); +} + + +/* check that argument has no extra characters at the end */ +#define notail(x) {if ((x)[2] != '\0') return -1;} + + +static int collectargs (char **argv, int *pi, int *pv, int *pe) { + int i; + for (i = 1; argv[i] != NULL; i++) { + if (argv[i][0] != '-') /* not an option? */ + return i; + switch (argv[i][1]) { /* option */ + case '-': + notail(argv[i]); + return (argv[i+1] != NULL ? i+1 : 0); + case '\0': + return i; + case 'i': + notail(argv[i]); + *pi = 1; /* go through */ + case 'v': + notail(argv[i]); + *pv = 1; + break; + case 'e': + *pe = 1; /* go through */ + case 'l': + if (argv[i][2] == '\0') { + i++; + if (argv[i] == NULL) return -1; + } + break; + default: return -1; /* invalid option */ + } + } + return 0; +} + + +static int runargs (lua_State *L, char **argv, int n) { + int i; + for (i = 1; i < n; i++) { + if (argv[i] == NULL) continue; + lua_assert(argv[i][0] == '-'); + switch (argv[i][1]) { /* option */ + case 'e': { + const char *chunk = argv[i] + 2; + if (*chunk == '\0') chunk = argv[++i]; + lua_assert(chunk != NULL); + if (dostring(L, chunk, "=(command line)") != 0) + return 1; + break; + } + case 'l': { + const char *filename = argv[i] + 2; + if (*filename == '\0') filename = argv[++i]; + lua_assert(filename != NULL); + if (dolibrary(L, filename)) + return 1; /* stop if file fails */ + break; + } + default: break; + } + } + return 0; +} + + +static int handle_luainit (lua_State *L) { + const char *init = getenv(LUA_INIT); + if (init == NULL) return 0; /* status OK */ + else if (init[0] == '@') + return dofile(L, init+1); + else + return dostring(L, init, "=" LUA_INIT); +} + + +struct Smain { + int argc; + char **argv; + int status; +}; + + +static int pmain (lua_State *L) { + struct Smain *s = (struct Smain *)lua_touserdata(L, 1); + char **argv = s->argv; + int script; + int has_i = 0, has_v = 0, has_e = 0; + globalL = L; + if (argv[0] && argv[0][0]) progname = argv[0]; + lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */ + luaL_openlibs(L); /* open libraries */ + lua_gc(L, LUA_GCRESTART, 0); + s->status = handle_luainit(L); + if (s->status != 0) return 0; + script = collectargs(argv, &has_i, &has_v, &has_e); + if (script < 0) { /* invalid args? */ + print_usage(); + s->status = 1; + return 0; + } + if (has_v) print_version(); + s->status = runargs(L, argv, (script > 0) ? script : s->argc); + if (s->status != 0) return 0; + if (script) + s->status = handle_script(L, argv, script); + if (s->status != 0) return 0; + if (has_i) + dotty(L); + else if (script == 0 && !has_e && !has_v) { + if (lua_stdin_is_tty()) { + print_version(); + dotty(L); + } + else dofile(L, NULL); /* executes stdin as a file */ + } + return 0; +} + + +int main (int argc, char **argv) { + int status; + struct Smain s; + lua_State *L = lua_open(); /* create state */ + if (L == NULL) { + l_message(argv[0], "cannot create state: not enough memory"); + return EXIT_FAILURE; + } + s.argc = argc; + s.argv = argv; + status = lua_cpcall(L, &pmain, &s); + report(L, status); + lua_close(L); + return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS; +} + |