etc/trace.c

   1 /*
   2 * trace.c -- a simple execution tracer for Lua
   3 */
   4
   5 #include <stdio.h>
   6 #include <string.h>
   7 #include "lua.h"
   8 #include "lualib.h"
   9 #include "lauxlib.h"
  10
  11 static FILE* LOG;               /* log file */
  12 static int I=0;                 /* indentation level */
  13
  14 static void hook(lua_State *L, lua_Debug *ar)
  15 {
  16  const char* s="";
  17  switch (ar->event)
  18  {
  19   case LUA_HOOKTAILRET: ar->event=LUA_HOOKRET;
  20   case LUA_HOOKRET: s="return"; break;
  21   case LUA_HOOKCALL: s="call"; break;
  22   case LUA_HOOKLINE: s="line"; break;
  23   default: break;
  24  }
  25  fprintf(LOG,"[%d]\t%*s%s\t-- %d\n",I,I,"",s,ar->currentline);
  26  if (ar->event==LUA_HOOKCALL) ++I; else if (ar->event==LUA_HOOKRET) --I;
  27 }
  28
  29 static void start_trace(lua_State *L, FILE* logfile)
  30 {
  31  lua_sethook(L,hook,LUA_MASKCALL | LUA_MASKRET | LUA_MASKLINE, 0);
  32  LOG=logfile;
  33 }
  34
  35 static void stop_trace(lua_State *L)
  36 {
  37  lua_sethook(L,NULL,0,0);
  38  fclose(LOG);
  39 }
  40
  41 int main(void)
  42 {
  43  int rc;
  44  lua_State *L=lua_open();
  45  lua_baselibopen(L);
  46  lua_tablibopen(L);
  47  lua_iolibopen(L);
  48  lua_strlibopen(L);
  49  lua_mathlibopen(L);
  50  lua_dblibopen(L);
  51  start_trace(L,stderr);
  52  rc=lua_dofile(L,NULL);
  53  stop_trace(L);
  54  return rc;
  55 }