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 && !strchr(ls->mode, bc ? 'b' : 't')) {
  38     setstrV(L, L->top++, lj_err_str(L, LJ_ERR_XMODE));
  39     lj_err_throw(L, LUA_ERRSYNTAX);
  40   }
  41   pt = bc ? lj_bcread(ls) : lj_parse(ls);
  42   fn = lj_func_newL_empty(L, pt, tabref(L->env));
  43   /* Don't combine above/below into one statement. */
  44   setfuncV(L, L->top++, fn);
  45   return NULL;
  46 }
  47
  48 LUA_API int lua_loadx(lua_State *L, lua_Reader reader, void *data,
  49                       const char *chunkname, const char *mode)
  50 {
  51   LexState ls;
  52   int status;
  53   ls.rfunc = reader;
  54   ls.rdata = data;
  55   ls.chunkarg = chunkname ? chunkname : "?";
  56   ls.mode = mode;
  57   lj_buf_init(L, &ls.sb);
  58   status = lj_vm_cpcall(L, NULL, &ls, cpparser);
  59   lj_lex_cleanup(L, &ls);
  60   lj_gc_check(L);
  61   return status;
  62 }
  63
  64 LUA_API int lua_load(lua_State *L, lua_Reader reader, void *data,
  65                      const char *chunkname)
  66 {
  67   return lua_loadx(L, reader, data, chunkname, NULL);
  68 }
  69
  70 typedef struct FileReaderCtx {
  71   FILE *fp;
  72   char buf[LUAL_BUFFERSIZE];
  73 } FileReaderCtx;
  74
  75 static const char *reader_file(lua_State *L, void *ud, size_t *size)
  76 {
  77   FileReaderCtx *ctx = (FileReaderCtx *)ud;
  78   UNUSED(L);
  79   if (feof(ctx->fp)) return NULL;
  80   *size = fread(ctx->buf, 1, sizeof(ctx->buf), ctx->fp);
  81   return *size > 0 ? ctx->buf : NULL;
  82 }
  83
  84 LUALIB_API int luaL_loadfilex(lua_State *L, const char *filename,
  85                               const char *mode)
  86 {
  87   FileReaderCtx ctx;
  88   int status;
  89   const char *chunkname;
  90   if (filename) {
  91     ctx.fp = fopen(filename, "rb");
  92     if (ctx.fp == NULL) {
  93       lua_pushfstring(L, "cannot open %s: %s", filename, strerror(errno));
  94       return LUA_ERRFILE;
  95     }
  96     chunkname = lua_pushfstring(L, "@%s", filename);
  97   } else {
  98     ctx.fp = stdin;
  99     chunkname = "=stdin";
 100   }
 101   status = lua_loadx(L, reader_file, &ctx, chunkname, mode);
 102   if (ferror(ctx.fp)) {
 103     L->top -= filename ? 2 : 1;
 104     lua_pushfstring(L, "cannot read %s: %s", chunkname+1, strerror(errno));
 105     if (filename)
 106       fclose(ctx.fp);
 107     return LUA_ERRFILE;
 108   }
 109   if (filename) {
 110     L->top--;
 111     copyTV(L, L->top-1, L->top);
 112     fclose(ctx.fp);
 113   }
 114   return status;
 115 }
 116
 117 LUALIB_API int luaL_loadfile(lua_State *L, const char *filename)
 118 {
 119   return luaL_loadfilex(L, filename, NULL);
 120 }
 121
 122 typedef struct StringReaderCtx {
 123   const char *str;
 124   size_t size;
 125 } StringReaderCtx;
 126
 127 static const char *reader_string(lua_State *L, void *ud, size_t *size)
 128 {
 129   StringReaderCtx *ctx = (StringReaderCtx *)ud;
 130   UNUSED(L);
 131   if (ctx->size == 0) return NULL;
 132   *size = ctx->size;
 133   ctx->size = 0;
 134   return ctx->str;
 135 }
 136
 137 LUALIB_API int luaL_loadbufferx(lua_State *L, const char *buf, size_t size,
 138                                 const char *name, const char *mode)
 139 {
 140   StringReaderCtx ctx;
 141   ctx.str = buf;
 142   ctx.size = size;
 143   return lua_loadx(L, reader_string, &ctx, name, mode);
 144 }
 145
 146 LUALIB_API int luaL_loadbuffer(lua_State *L, const char *buf, size_t size,
 147                                const char *name)
 148 {
 149   return luaL_loadbufferx(L, buf, size, name, NULL);
 150 }
 151
 152 LUALIB_API int luaL_loadstring(lua_State *L, const char *s)
 153 {
 154   return luaL_loadbuffer(L, s, strlen(s), s);
 155 }
 156
 157 /* -- Dump bytecode ------------------------------------------------------- */
 158
 159 LUA_API int lua_dump(lua_State *L, lua_Writer writer, void *data)
 160 {
 161   cTValue *o = L->top-1;
 162   lj_checkapi(L->top > L->base, "top slot empty");
 163   if (tvisfunc(o) && isluafunc(funcV(o)))
 164     return lj_bcwrite(L, funcproto(funcV(o)), writer, data, 0);
 165   else
 166     return 1;
 167 }
 168