src/lj_load.c

   1 /*
   2 ** Load and dump code.
   3 ** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #include <errno.h>
   7 #include <stdio.h>
   8
   9 #define lj_load_c
  10 #define LUA_CORE
  11
  12 #include "lua.h"
  13 #include "lauxlib.h"
  14
  15 #include "lj_obj.h"
  16 #include "lj_gc.h"
  17 #include "lj_err.h"
  18 #include "lj_buf.h"
  19 #include "lj_func.h"
  20 #include "lj_frame.h"
  21 #include "lj_vm.h"
  22 #include "lj_lex.h"
  23 #include "lj_bcdump.h"
  24 #include "lj_parse.h"
  25
  26 /* -- Load Lua source code and bytecode ----------------------------------- */
  27
  28 static TValue *cpparser(lua_State *L, lua_CFunction dummy, void *ud)
  29 {
  30   LexState *ls = (LexState *)ud;
  31   GCproto *pt;
  32   GCfunc *fn;
  33   int bc;
  34   UNUSED(dummy);
  35   cframe_errfunc(L->cframe) = -1;  /* Inherit error function. */
  36   bc = lj_lex_setup(L, ls);
  37   if (ls->mode) {
  38     int xmode = 1;
  39     const char *mode = ls->mode;
  40     char c;
  41     while ((c = *mode++)) {
  42       if (c == (bc ? 'b' : 't')) xmode = 0;
  43       if (c == (LJ_FR2 ? 'W' : 'X')) ls->fr2 = !LJ_FR2;
  44     }
  45     if (xmode) {
  46       setstrV(L, L->top++, lj_err_str(L, LJ_ERR_XMODE));
  47       lj_err_throw(L, LUA_ERRSYNTAX);
  48     }
  49   }
  50   pt = bc ? lj_bcread(ls) : lj_parse(ls);
  51   if (ls->fr2 == LJ_FR2) {
  52     fn = lj_func_newL_empty(L, pt, tabref(L->env));
  53     /* Don't combine above/below into one statement. */
  54     setfuncV(L, L->top++, fn);
  55   } else {
  56     /* Non-native generation returns a dumpable, but non-runnable prototype. */
  57     setprotoV(L, L->top++, pt);
  58   }
  59   return NULL;
  60 }
  61
  62 LUA_API int lua_loadx(lua_State *L, lua_Reader reader, void *data,
  63                       const char *chunkname, const char *mode)
  64 {
  65   LexState ls;
  66   int status;
  67   ls.rfunc = reader;
  68   ls.rdata = data;
  69   ls.chunkarg = chunkname ? chunkname : "?";
  70   ls.mode = mode;
  71   lj_buf_init(L, &ls.sb);
  72   status = lj_vm_cpcall(L, NULL, &ls, cpparser);
  73   lj_lex_cleanup(L, &ls);
  74   lj_gc_check(L);
  75   return status;
  76 }
  77
  78 LUA_API int lua_load(lua_State *L, lua_Reader reader, void *data,
  79                      const char *chunkname)
  80 {
  81   return lua_loadx(L, reader, data, chunkname, NULL);
  82 }
  83
  84 typedef struct FileReaderCtx {
  85   FILE *fp;
  86   char buf[LUAL_BUFFERSIZE];
  87 } FileReaderCtx;
  88
  89 static const char *reader_file(lua_State *L, void *ud, size_t *size)
  90 {
  91   FileReaderCtx *ctx = (FileReaderCtx *)ud;
  92   UNUSED(L);
  93   if (feof(ctx->fp)) return NULL;
  94   *size = fread(ctx->buf, 1, sizeof(ctx->buf), ctx->fp);
  95   return *size > 0 ? ctx->buf : NULL;
  96 }
  97
  98 LUALIB_API int luaL_loadfilex(lua_State *L, const char *filename,
  99                               const char *mode)
 100 {
 101   FileReaderCtx ctx;
 102   int status;
 103   const char *chunkname;
 104   if (filename) {
 105     ctx.fp = fopen(filename, "rb");
 106     if (ctx.fp == NULL) {
 107       lua_pushfstring(L, "cannot open %s: %s", filename, strerror(errno));
 108       return LUA_ERRFILE;
 109     }
 110     chunkname = lua_pushfstring(L, "@%s", filename);
 111   } else {
 112     ctx.fp = stdin;
 113     chunkname = "=stdin";
 114   }
 115   status = lua_loadx(L, reader_file, &ctx, chunkname, mode);
 116   if (ferror(ctx.fp)) {
 117     L->top -= filename ? 2 : 1;
 118     lua_pushfstring(L, "cannot read %s: %s", chunkname+1, strerror(errno));
 119     if (filename)
 120       fclose(ctx.fp);
 121     return LUA_ERRFILE;
 122   }
 123   if (filename) {
 124     L->top--;
 125     copyTV(L, L->top-1, L->top);
 126     fclose(ctx.fp);
 127   }
 128   return status;
 129 }
 130
 131 LUALIB_API int luaL_loadfile(lua_State *L, const char *filename)
 132 {
 133   return luaL_loadfilex(L, filename, NULL);
 134 }
 135
 136 typedef struct StringReaderCtx {
 137   const char *str;
 138   size_t size;
 139 } StringReaderCtx;
 140
 141 static const char *reader_string(lua_State *L, void *ud, size_t *size)
 142 {
 143   StringReaderCtx *ctx = (StringReaderCtx *)ud;
 144   UNUSED(L);
 145   if (ctx->size == 0) return NULL;
 146   *size = ctx->size;
 147   ctx->size = 0;
 148   return ctx->str;
 149 }
 150
 151 LUALIB_API int luaL_loadbufferx(lua_State *L, const char *buf, size_t size,
 152                                 const char *name, const char *mode)
 153 {
 154   StringReaderCtx ctx;
 155   ctx.str = buf;
 156   ctx.size = size;
 157   return lua_loadx(L, reader_string, &ctx, name, mode);
 158 }
 159
 160 LUALIB_API int luaL_loadbuffer(lua_State *L, const char *buf, size_t size,
 161                                const char *name)
 162 {
 163   return luaL_loadbufferx(L, buf, size, name, NULL);
 164 }
 165
 166 LUALIB_API int luaL_loadstring(lua_State *L, const char *s)
 167 {
 168   return luaL_loadbuffer(L, s, strlen(s), s);
 169 }
 170
 171 /* -- Dump bytecode ------------------------------------------------------- */
 172
 173 LUA_API int lua_dump(lua_State *L, lua_Writer writer, void *data)
 174 {
 175   cTValue *o = L->top-1;
 176   uint32_t flags = LJ_FR2*BCDUMP_F_FR2;  /* Default mode for legacy C API. */
 177   lj_checkapi(L->top > L->base, "top slot empty");
 178   if (tvisfunc(o) && isluafunc(funcV(o)))
 179     return lj_bcwrite(L, funcproto(funcV(o)), writer, data, flags);
 180   else
 181     return 1;
 182 }
 183