1 files changed, 477 insertions, 0 deletions

diff --git a/src/lua/ldblib.c b/src/lua/ldblib.c
new file mode 100644
index 0000000..59eb8f0
--- /dev/null
+++ b/src/lua/ldblib.c
@@ -0,0 +1,477 @@
+/*
+** $Id: ldblib.c $
+** Interface from Lua to its debug API
+** See Copyright Notice in lua.h
+*/
+
+#define ldblib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/*
+** The hook table at registry[HOOKKEY] maps threads to their current
+** hook function.
+*/
+static const char *const HOOKKEY = "_HOOKKEY";
+
+
+/*
+** If L1 != L, L1 can be in any state, and therefore there are no
+** guarantees about its stack space; any push in L1 must be
+** checked.
+*/
+static void checkstack (lua_State *L, lua_State *L1, int n) {
+  if (L != L1 && !lua_checkstack(L1, n))
+    luaL_error(L, "stack overflow");
+}
+
+
+static int db_getregistry (lua_State *L) {
+  lua_pushvalue(L, LUA_REGISTRYINDEX);
+  return 1;
+}
+
+
+static int db_getmetatable (lua_State *L) {
+  luaL_checkany(L, 1);
+  if (!lua_getmetatable(L, 1)) {
+    lua_pushnil(L);  /* no metatable */
+  }
+  return 1;
+}
+
+
+static int db_setmetatable (lua_State *L) {
+  int t = lua_type(L, 2);
+  luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
+  lua_settop(L, 2);
+  lua_setmetatable(L, 1);
+  return 1;  /* return 1st argument */
+}
+
+
+static int db_getuservalue (lua_State *L) {
+  int n = (int)luaL_optinteger(L, 2, 1);
+  if (lua_type(L, 1) != LUA_TUSERDATA)
+    luaL_pushfail(L);
+  else if (lua_getiuservalue(L, 1, n) != LUA_TNONE) {
+    lua_pushboolean(L, 1);
+    return 2;
+  }
+  return 1;
+}
+
+
+static int db_setuservalue (lua_State *L) {
+  int n = (int)luaL_optinteger(L, 3, 1);
+  luaL_checktype(L, 1, LUA_TUSERDATA);
+  luaL_checkany(L, 2);
+  lua_settop(L, 2);
+  if (!lua_setiuservalue(L, 1, n))
+    luaL_pushfail(L);
+  return 1;
+}
+
+
+/*
+** Auxiliary function used by several library functions: check for
+** an optional thread as function's first argument and set 'arg' with
+** 1 if this argument is present (so that functions can skip it to
+** access their other arguments)
+*/
+static lua_State *getthread (lua_State *L, int *arg) {
+  if (lua_isthread(L, 1)) {
+    *arg = 1;
+    return lua_tothread(L, 1);
+  }
+  else {
+    *arg = 0;
+    return L;  /* function will operate over current thread */
+  }
+}
+
+
+/*
+** Variations of 'lua_settable', used by 'db_getinfo' to put results
+** from 'lua_getinfo' into result table. Key is always a string;
+** value can be a string, an int, or a boolean.
+*/
+static void settabss (lua_State *L, const char *k, const char *v) {
+  lua_pushstring(L, v);
+  lua_setfield(L, -2, k);
+}
+
+static void settabsi (lua_State *L, const char *k, int v) {
+  lua_pushinteger(L, v);
+  lua_setfield(L, -2, k);
+}
+
+static void settabsb (lua_State *L, const char *k, int v) {
+  lua_pushboolean(L, v);
+  lua_setfield(L, -2, k);
+}
+
+
+/*
+** In function 'db_getinfo', the call to 'lua_getinfo' may push
+** results on the stack; later it creates the result table to put
+** these objects. Function 'treatstackoption' puts the result from
+** 'lua_getinfo' on top of the result table so that it can call
+** 'lua_setfield'.
+*/
+static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
+  if (L == L1)
+    lua_rotate(L, -2, 1);  /* exchange object and table */
+  else
+    lua_xmove(L1, L, 1);  /* move object to the "main" stack */
+  lua_setfield(L, -2, fname);  /* put object into table */
+}
+
+
+/*
+** Calls 'lua_getinfo' and collects all results in a new table.
+** L1 needs stack space for an optional input (function) plus
+** two optional outputs (function and line table) from function
+** 'lua_getinfo'.
+*/
+static int db_getinfo (lua_State *L) {
+  lua_Debug ar;
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  const char *options = luaL_optstring(L, arg+2, "flnSrtu");
+  checkstack(L, L1, 3);
+  if (lua_isfunction(L, arg + 1)) {  /* info about a function? */
+    options = lua_pushfstring(L, ">%s", options);  /* add '>' to 'options' */
+    lua_pushvalue(L, arg + 1);  /* move function to 'L1' stack */
+    lua_xmove(L, L1, 1);
+  }
+  else {  /* stack level */
+    if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) {
+      luaL_pushfail(L);  /* level out of range */
+      return 1;
+    }
+  }
+  if (!lua_getinfo(L1, options, &ar))
+    return luaL_argerror(L, arg+2, "invalid option");
+  lua_newtable(L);  /* table to collect results */
+  if (strchr(options, 'S')) {
+    lua_pushlstring(L, ar.source, ar.srclen);
+    lua_setfield(L, -2, "source");
+    settabss(L, "short_src", ar.short_src);
+    settabsi(L, "linedefined", ar.linedefined);
+    settabsi(L, "lastlinedefined", ar.lastlinedefined);
+    settabss(L, "what", ar.what);
+  }
+  if (strchr(options, 'l'))
+    settabsi(L, "currentline", ar.currentline);
+  if (strchr(options, 'u')) {
+    settabsi(L, "nups", ar.nups);
+    settabsi(L, "nparams", ar.nparams);
+    settabsb(L, "isvararg", ar.isvararg);
+  }
+  if (strchr(options, 'n')) {
+    settabss(L, "name", ar.name);
+    settabss(L, "namewhat", ar.namewhat);
+  }
+  if (strchr(options, 'r')) {
+    settabsi(L, "ftransfer", ar.ftransfer);
+    settabsi(L, "ntransfer", ar.ntransfer);
+  }
+  if (strchr(options, 't'))
+    settabsb(L, "istailcall", ar.istailcall);
+  if (strchr(options, 'L'))
+    treatstackoption(L, L1, "activelines");
+  if (strchr(options, 'f'))
+    treatstackoption(L, L1, "func");
+  return 1;  /* return table */
+}
+
+
+static int db_getlocal (lua_State *L) {
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  int nvar = (int)luaL_checkinteger(L, arg + 2);  /* local-variable index */
+  if (lua_isfunction(L, arg + 1)) {  /* function argument? */
+    lua_pushvalue(L, arg + 1);  /* push function */
+    lua_pushstring(L, lua_getlocal(L, NULL, nvar));  /* push local name */
+    return 1;  /* return only name (there is no value) */
+  }
+  else {  /* stack-level argument */
+    lua_Debug ar;
+    const char *name;
+    int level = (int)luaL_checkinteger(L, arg + 1);
+    if (!lua_getstack(L1, level, &ar))  /* out of range? */
+      return luaL_argerror(L, arg+1, "level out of range");
+    checkstack(L, L1, 1);
+    name = lua_getlocal(L1, &ar, nvar);
+    if (name) {
+      lua_xmove(L1, L, 1);  /* move local value */
+      lua_pushstring(L, name);  /* push name */
+      lua_rotate(L, -2, 1);  /* re-order */
+      return 2;
+    }
+    else {
+      luaL_pushfail(L);  /* no name (nor value) */
+      return 1;
+    }
+  }
+}
+
+
+static int db_setlocal (lua_State *L) {
+  int arg;
+  const char *name;
+  lua_State *L1 = getthread(L, &arg);
+  lua_Debug ar;
+  int level = (int)luaL_checkinteger(L, arg + 1);
+  int nvar = (int)luaL_checkinteger(L, arg + 2);
+  if (!lua_getstack(L1, level, &ar))  /* out of range? */
+    return luaL_argerror(L, arg+1, "level out of range");
+  luaL_checkany(L, arg+3);
+  lua_settop(L, arg+3);
+  checkstack(L, L1, 1);
+  lua_xmove(L, L1, 1);
+  name = lua_setlocal(L1, &ar, nvar);
+  if (name == NULL)
+    lua_pop(L1, 1);  /* pop value (if not popped by 'lua_setlocal') */
+  lua_pushstring(L, name);
+  return 1;
+}
+
+
+/*
+** get (if 'get' is true) or set an upvalue from a closure
+*/
+static int auxupvalue (lua_State *L, int get) {
+  const char *name;
+  int n = (int)luaL_checkinteger(L, 2);  /* upvalue index */
+  luaL_checktype(L, 1, LUA_TFUNCTION);  /* closure */
+  name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
+  if (name == NULL) return 0;
+  lua_pushstring(L, name);
+  lua_insert(L, -(get+1));  /* no-op if get is false */
+  return get + 1;
+}
+
+
+static int db_getupvalue (lua_State *L) {
+  return auxupvalue(L, 1);
+}
+
+
+static int db_setupvalue (lua_State *L) {
+  luaL_checkany(L, 3);
+  return auxupvalue(L, 0);
+}
+
+
+/*
+** Check whether a given upvalue from a given closure exists and
+** returns its index
+*/
+static int checkupval (lua_State *L, int argf, int argnup) {
+  int nup = (int)luaL_checkinteger(L, argnup);  /* upvalue index */
+  luaL_checktype(L, argf, LUA_TFUNCTION);  /* closure */
+  luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup,
+                   "invalid upvalue index");
+  return nup;
+}
+
+
+static int db_upvalueid (lua_State *L) {
+  int n = checkupval(L, 1, 2);
+  lua_pushlightuserdata(L, lua_upvalueid(L, 1, n));
+  return 1;
+}
+
+
+static int db_upvaluejoin (lua_State *L) {
+  int n1 = checkupval(L, 1, 2);
+  int n2 = checkupval(L, 3, 4);
+  luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");
+  luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");
+  lua_upvaluejoin(L, 1, n1, 3, n2);
+  return 0;
+}
+
+
+/*
+** Call hook function registered at hook table for the current
+** thread (if there is one)
+*/
+static void hookf (lua_State *L, lua_Debug *ar) {
+  static const char *const hooknames[] =
+    {"call", "return", "line", "count", "tail call"};
+  lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY);
+  lua_pushthread(L);
+  if (lua_rawget(L, -2) == LUA_TFUNCTION) {  /* is there a hook function? */
+    lua_pushstring(L, hooknames[(int)ar->event]);  /* push event name */
+    if (ar->currentline >= 0)
+      lua_pushinteger(L, ar->currentline);  /* push current line */
+    else lua_pushnil(L);
+    lua_assert(lua_getinfo(L, "lS", ar));
+    lua_call(L, 2, 0);  /* call hook function */
+  }
+}
+
+
+/*
+** Convert a string mask (for 'sethook') into a bit mask
+*/
+static int makemask (const char *smask, int count) {
+  int mask = 0;
+  if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
+  if (strchr(smask, 'r')) mask |= LUA_MASKRET;
+  if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
+  if (count > 0) mask |= LUA_MASKCOUNT;
+  return mask;
+}
+
+
+/*
+** Convert a bit mask (for 'gethook') into a string mask
+*/
+static char *unmakemask (int mask, char *smask) {
+  int i = 0;
+  if (mask & LUA_MASKCALL) smask[i++] = 'c';
+  if (mask & LUA_MASKRET) smask[i++] = 'r';
+  if (mask & LUA_MASKLINE) smask[i++] = 'l';
+  smask[i] = '\0';
+  return smask;
+}
+
+
+static int db_sethook (lua_State *L) {
+  int arg, mask, count;
+  lua_Hook func;
+  lua_State *L1 = getthread(L, &arg);
+  if (lua_isnoneornil(L, arg+1)) {  /* no hook? */
+    lua_settop(L, arg+1);
+    func = NULL; mask = 0; count = 0;  /* turn off hooks */
+  }
+  else {
+    const char *smask = luaL_checkstring(L, arg+2);
+    luaL_checktype(L, arg+1, LUA_TFUNCTION);
+    count = (int)luaL_optinteger(L, arg + 3, 0);
+    func = hookf; mask = makemask(smask, count);
+  }
+  if (!luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY)) {
+    /* table just created; initialize it */
+    lua_pushstring(L, "k");
+    lua_setfield(L, -2, "__mode");  /** hooktable.__mode = "k" */
+    lua_pushvalue(L, -1);
+    lua_setmetatable(L, -2);  /* metatable(hooktable) = hooktable */
+  }
+  checkstack(L, L1, 1);
+  lua_pushthread(L1); lua_xmove(L1, L, 1);  /* key (thread) */
+  lua_pushvalue(L, arg + 1);  /* value (hook function) */
+  lua_rawset(L, -3);  /* hooktable[L1] = new Lua hook */
+  lua_sethook(L1, func, mask, count);
+  return 0;
+}
+
+
+static int db_gethook (lua_State *L) {
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  char buff[5];
+  int mask = lua_gethookmask(L1);
+  lua_Hook hook = lua_gethook(L1);
+  if (hook == NULL) {  /* no hook? */
+    luaL_pushfail(L);
+    return 1;
+  }
+  else if (hook != hookf)  /* external hook? */
+    lua_pushliteral(L, "external hook");
+  else {  /* hook table must exist */
+    lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY);
+    checkstack(L, L1, 1);
+    lua_pushthread(L1); lua_xmove(L1, L, 1);
+    lua_rawget(L, -2);   /* 1st result = hooktable[L1] */
+    lua_remove(L, -2);  /* remove hook table */
+  }
+  lua_pushstring(L, unmakemask(mask, buff));  /* 2nd result = mask */
+  lua_pushinteger(L, lua_gethookcount(L1));  /* 3rd result = count */
+  return 3;
+}
+
+
+static int db_debug (lua_State *L) {
+  for (;;) {
+    char buffer[250];
+    lua_writestringerror("%s", "lua_debug> ");
+    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
+        strcmp(buffer, "cont\n") == 0)
+      return 0;
+    if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
+        lua_pcall(L, 0, 0, 0))
+      lua_writestringerror("%s\n", luaL_tolstring(L, -1, NULL));
+    lua_settop(L, 0);  /* remove eventual returns */
+  }
+}
+
+
+static int db_traceback (lua_State *L) {
+  int arg;
+  lua_State *L1 = getthread(L, &arg);
+  const char *msg = lua_tostring(L, arg + 1);
+  if (msg == NULL && !lua_isnoneornil(L, arg + 1))  /* non-string 'msg'? */
+    lua_pushvalue(L, arg + 1);  /* return it untouched */
+  else {
+    int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0);
+    luaL_traceback(L, L1, msg, level);
+  }
+  return 1;
+}
+
+
+static int db_setcstacklimit (lua_State *L) {
+  int limit = (int)luaL_checkinteger(L, 1);
+  int res = lua_setcstacklimit(L, limit);
+  if (res == 0)
+    lua_pushboolean(L, 0);
+  else
+    lua_pushinteger(L, res);
+  return 1;
+}
+
+
+static const luaL_Reg dblib[] = {
+  {"debug", db_debug},
+  {"getuservalue", db_getuservalue},
+  {"gethook", db_gethook},
+  {"getinfo", db_getinfo},
+  {"getlocal", db_getlocal},
+  {"getregistry", db_getregistry},
+  {"getmetatable", db_getmetatable},
+  {"getupvalue", db_getupvalue},
+  {"upvaluejoin", db_upvaluejoin},
+  {"upvalueid", db_upvalueid},
+  {"setuservalue", db_setuservalue},
+  {"sethook", db_sethook},
+  {"setlocal", db_setlocal},
+  {"setmetatable", db_setmetatable},
+  {"setupvalue", db_setupvalue},
+  {"traceback", db_traceback},
+  {"setcstacklimit", db_setcstacklimit},
+  {NULL, NULL}
+};
+
+
+LUAMOD_API int luaopen_debug (lua_State *L) {
+  luaL_newlib(L, dblib);
+  return 1;
+}
+