diff options
Diffstat (limited to 'src/lua.c')
| -rw-r--r-- | src/lua.c | 230 |
1 files changed, 151 insertions, 79 deletions
@@ -1,5 +1,5 @@ /* -** $Id: lua.c,v 1.160.1.2 2007/12/28 15:32:23 roberto Exp $ +** $Id: lua.c,v 1.182 2009/12/22 16:47:12 roberto Exp $ ** Lua stand-alone interpreter ** See Copyright Notice in lua.h */ @@ -18,6 +18,69 @@ #include "lualib.h" +#if !defined(LUA_PROMPT) +#define LUA_PROMPT "> " +#define LUA_PROMPT2 ">> " +#endif + +#if !defined(LUA_PROGNAME) +#define LUA_PROGNAME "lua" +#endif + +#if !defined(LUA_MAXINPUT) +#define LUA_MAXINPUT 512 +#endif + +#if !defined(LUA_INIT_VAR) +#define LUA_INIT_VAR "LUA_INIT" +#endif + + +/* +** lua_stdin_is_tty detects whether the standard input is a 'tty' (that +** is, whether we're running lua interactively). +*/ +#if defined(LUA_USE_ISATTY) +#include <unistd.h> +#define lua_stdin_is_tty() isatty(0) +#elif defined(LUA_WIN) +#include <io.h> +#include <stdio.h> +#define lua_stdin_is_tty() _isatty(_fileno(stdin)) +#else +#define lua_stdin_is_tty() 1 /* assume stdin is a tty */ +#endif + + +/* +** lua_readline defines how to show a prompt and then read a line from +** the standard input. +** lua_saveline defines how to "save" a read line in a "history". +** lua_freeline defines how to free a line read by lua_readline. +*/ +#if defined(LUA_USE_READLINE) + +#include <stdio.h> +#include <readline/readline.h> +#include <readline/history.h> +#define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL) +#define lua_saveline(L,idx) \ + if (lua_rawlen(L,idx) > 0) /* non-empty line? */ \ + add_history(lua_tostring(L, idx)); /* add it to history */ +#define lua_freeline(L,b) ((void)L, free(b)) + +#elif !defined(lua_readline) + +#define lua_readline(L,b,p) \ + ((void)L, fputs(p, stdout), fflush(stdout), /* show prompt */ \ + fgets(b, LUA_MAXINPUT, stdin) != NULL) /* get line */ +#define lua_saveline(L,idx) { (void)L; (void)idx; } +#define lua_freeline(L,b) { (void)L; (void)b; } + +#endif + + + static lua_State *globalL = NULL; @@ -41,7 +104,7 @@ static void laction (int i) { static void print_usage (void) { fprintf(stderr, - "usage: %s [options] [script [args]].\n" + "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" @@ -63,32 +126,38 @@ static void l_message (const char *pname, const char *msg) { static int report (lua_State *L, int status) { - if (status && !lua_isnil(L, -1)) { + if (status != LUA_OK && !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); + /* force a complete garbage collection in case of errors */ + lua_gc(L, LUA_GCCOLLECT, 0); } 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)) { +/* the next function is called unprotected, so it must avoid errors */ +static void finalreport (lua_State *L, int status) { + if (status != LUA_OK) { + const char *msg = (lua_type(L, -1) == LUA_TSTRING) ? lua_tostring(L, -1) + : NULL; + if (msg == NULL) msg = "(error object is not a string)"; + l_message(progname, msg); lua_pop(L, 1); - return 1; } - lua_getfield(L, -1, "traceback"); - if (!lua_isfunction(L, -1)) { - lua_pop(L, 2); - return 1; +} + + +static int traceback (lua_State *L) { + const char *msg = lua_tostring(L, 1); + if (msg) + luaL_traceback(L, L, msg, 1); + else if (!lua_isnoneornil(L, 1)) { /* is there an error object? */ + if (!luaL_callmeta(L, 1, "__tostring")) /* try its 'tostring' metamethod */ + lua_pushliteral(L, "(no error message)"); } - 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; } @@ -98,18 +167,17 @@ static int docall (lua_State *L, int narg, int clear) { 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 */ + globalL = L; /* to be available to 'laction' */ 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); + printf("%s\n", LUA_COPYRIGHT); } @@ -132,19 +200,21 @@ static int getargs (lua_State *L, char **argv, int n) { static int dofile (lua_State *L, const char *name) { - int status = luaL_loadfile(L, name) || docall(L, 0, 1); + int status = luaL_loadfile(L, name); + if (status == LUA_OK) status = 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); + int status = luaL_loadbuffer(L, s, strlen(s), name); + if (status == LUA_OK) status = docall(L, 0, 1); return report(L, status); } static int dolibrary (lua_State *L, const char *name) { - lua_getglobal(L, "require"); + lua_getfield(L, LUA_ENVIRONINDEX, "require"); lua_pushstring(L, name); return report(L, docall(L, 1, 1)); } @@ -152,20 +222,22 @@ static int dolibrary (lua_State *L, const char *name) { static const char *get_prompt (lua_State *L, int firstline) { const char *p; - lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2"); + lua_getfield(L, LUA_ENVIRONINDEX, 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; } +/* mark in error messages for incomplete statements */ +#define mark "<eof>" +#define marklen (sizeof(mark) - 1) 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) { + if (lmsg >= marklen && strcmp(msg + lmsg - marklen, mark) == 0) { lua_pop(L, 1); return 1; } @@ -199,7 +271,9 @@ static int loadline (lua_State *L) { 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"); + size_t l; + const char *line = lua_tolstring(L, 1, &l); + status = luaL_loadbuffer(L, line, l, "=stdin"); if (!incomplete(L, status)) break; /* cannot try to add lines? */ if (!pushline(L, 0)) /* no more input? */ return -1; @@ -218,19 +292,20 @@ static void dotty (lua_State *L) { const char *oldprogname = progname; progname = NULL; while ((status = loadline(L)) != -1) { - if (status == 0) status = docall(L, 0, 0); + if (status == LUA_OK) status = docall(L, 0, 0); report(L, status); - if (status == 0 && lua_gettop(L) > 0) { /* any result to print? */ - lua_getglobal(L, "print"); + if (status == LUA_OK && lua_gettop(L) > 0) { /* any result to print? */ + luaL_checkstack(L, LUA_MINSTACK, "too many results to print"); + lua_getfield(L, LUA_ENVIRONINDEX, "print"); lua_insert(L, 1); - if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0) + if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != LUA_OK) 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); + luai_writestring("\n", 1); fflush(stdout); progname = oldprogname; } @@ -240,22 +315,22 @@ 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"); + lua_setfield(L, LUA_ENVIRONINDEX, "arg"); fname = argv[n]; - if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0) + 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) + if (status == LUA_OK) status = docall(L, narg, 0); else - lua_pop(L, narg); + 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;} +#define noextrachars(x) {if ((x)[2] != '\0') return -1;} static int collectargs (char **argv, int *pi, int *pv, int *pe) { @@ -265,15 +340,15 @@ static int collectargs (char **argv, int *pi, int *pv, int *pe) { return i; switch (argv[i][1]) { /* option */ case '-': - notail(argv[i]); + noextrachars(argv[i]); return (argv[i+1] != NULL ? i+1 : 0); case '\0': return i; case 'i': - notail(argv[i]); + noextrachars(argv[i]); *pi = 1; /* go through */ case 'v': - notail(argv[i]); + noextrachars(argv[i]); *pv = 1; break; case 'e': @@ -301,92 +376,89 @@ static int runargs (lua_State *L, char **argv, int n) { 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; + if (dostring(L, chunk, "=(command line)") != LUA_OK) + return 0; 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 */ + if (dolibrary(L, filename) != LUA_OK) + return 0; /* stop if file fails */ break; } default: break; } } - return 0; + return 1; } static int handle_luainit (lua_State *L) { - const char *init = getenv(LUA_INIT); - if (init == NULL) return 0; /* status OK */ + const char *init = getenv(LUA_INIT_VAR); + if (init == NULL) return LUA_OK; else if (init[0] == '@') return dofile(L, init+1); else - return dostring(L, init, "=" LUA_INIT); + return dostring(L, init, "=" LUA_INIT_VAR); } -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 argc = lua_tointeger(L, 1); + char **argv = (char **)lua_touserdata(L, 2); 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) + /* open standard libraries */ + luaL_checkversion(L); + lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */ + luaL_openlibs(L); /* open libraries */ + lua_gc(L, LUA_GCRESTART, 0); + /* run LUA_INIT */ + if (handle_luainit(L) != LUA_OK) return 0; + /* execute arguments -e and -l */ + if (!runargs(L, argv, (script > 0) ? script : argc)) return 0; + /* execute main script (if there is one) */ + if (script && handle_script(L, argv, script) != LUA_OK) return 0; + if (has_i) /* -i option? */ dotty(L); - else if (script == 0 && !has_e && !has_v) { + else if (script == 0 && !has_e && !has_v) { /* no arguments? */ if (lua_stdin_is_tty()) { print_version(); dotty(L); } else dofile(L, NULL); /* executes stdin as a file */ } - return 0; + lua_pushboolean(L, 1); /* signal no errors */ + return 1; } int main (int argc, char **argv) { - int status; - struct Smain s; - lua_State *L = lua_open(); /* create state */ + static lua_CFunction ppmain = &pmain; + int status, result; + lua_State *L = luaL_newstate(); /* 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); + /* call 'pmain' in protected mode */ + lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_CPCALL); /* calling function */ + lua_pushlightuserdata(L, &ppmain); + lua_pushinteger(L, argc); + lua_pushlightuserdata(L, argv); + status = lua_pcall(L, 3, 1, 0); + result = lua_toboolean(L, -1); /* get result */ + finalreport(L, status); lua_close(L); - return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS; + return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE; } |