lean2/src/util/lua.cpp

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/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <memory>
#include "util/lua.h"
#include "util/script_exception.h"
#include "util/debug.h"
namespace lean {
/**
\brief luaL_setfuncs replacement. The function luaL_setfuncs is only available in Lua 5.2.
*/
void setfuncs(lua_State * L, luaL_Reg const * l, int nup) {
luaL_checkstack(L, nup, "too many upvalues");
for (; l->name != NULL; l++) {
// fill the table with given functions
for (int i = 0; i < nup; i++) // copy upvalues to the top
lua_pushvalue(L, -nup);
lua_pushcclosure(L, l->func, nup); // closure with those upvalues
lua_setfield(L, -(nup + 2), l->name);
}
lua_pop(L, nup); // remove upvalues
}
/**
\brief luaL_testudata replacement.
*/
bool testudata(lua_State * L, int ud, char const * tname) {
void * p = lua_touserdata(L, ud);
if (p != nullptr) {
if (lua_getmetatable(L, ud)) {
luaL_getmetatable(L, tname);
if (!lua_rawequal(L, -1, -2))
p = nullptr;
lua_pop(L, 2);
return p;
}
}
return nullptr; // value is not a userdata with a metatable
}
int load(lua_State * L, lua_Reader reader, void * data, char const * source) {
#if LUA_VERSION_NUM < 502
return lua_load(L, reader, data, source);
#else
return lua_load(L, reader, data, source, nullptr);
#endif
}
size_t objlen(lua_State * L, int idx) {
#if LUA_VERSION_NUM < 502
return lua_objlen(L, idx);
#else
return lua_rawlen(L, idx);
#endif
}
int lessthan(lua_State * L, int idx1, int idx2) {
#if LUA_VERSION_NUM < 502
return lua_lessthan(L, idx1, idx2);
#else
return lua_compare(L, idx1, idx2, LUA_OPLT);
#endif
}
int equal(lua_State * L, int idx1, int idx2) {
#if LUA_VERSION_NUM < 502
return lua_equal(L, idx1, idx2);
#else
return lua_compare(L, idx1, idx2, LUA_OPEQ);
#endif
}
int get_nonnil_top(lua_State * L) {
int top = lua_gettop(L);
while (top > 0 && lua_isnil(L, top))
top--;
return top;
}
static void exec(lua_State * L) {
pcall(L, 0, LUA_MULTRET, 0);
}
void check_result(lua_State * L, int result) {
if (result) {
if (is_exception(L, -1))
to_exception(L, -1).rethrow();
else
throw script_exception(lua_tostring(L, -1));
}
}
void dofile(lua_State * L, char const * fname) {
int result = luaL_loadfile(L, fname);
check_result(L, result);
exec(L);
}
void dostring(lua_State * L, char const * str) {
int result = luaL_loadstring(L, str);
check_result(L, result);
exec(L);
}
void pcall(lua_State * L, int nargs, int nresults, int errorfun) {
int result = lua_pcall(L, nargs, nresults, errorfun);
check_result(L, result);
}
bool resume(lua_State * L, int nargs) {
#if LUA_VERSION_NUM < 502
int result = lua_resume(L, nargs);
#else
int result = lua_resume(L, nullptr, nargs);
#endif
if (result == LUA_YIELD)
return false;
if (result == 0)
return true;
check_result(L, result);
lean_unreachable();
return true;
}
/**
\brief Wrapper for "customers" that are only using a subset
of Lean libraries.
*/
int safe_function_wrapper(lua_State * L, lua_CFunction f) {
try {
return f(L);
} catch (script_exception & e) {
lua_pushstring(L, e.what());
} catch (exception & e) {
push_exception(L, e);
} catch (std::bad_alloc &) {
lua_pushstring(L, "out of memory");
} catch (std::exception & e) {
lua_pushstring(L, e.what());
} catch(...) {
lua_pushstring(L, "unknown error");
}
return lua_error(L);
}
void set_migrate_fn_field(lua_State * L, int i, lua_migrate_fn fn) {
lean_assert(lua_istable(L, i));
lua_pushvalue(L, i); // copy table to the top of the stack
lua_pushlightuserdata(L, reinterpret_cast<void*>(fn));
lua_setfield(L, -2, "___migrate");
lua_pop(L, 1); // remove table from the stack
}
/**
\brief Return the value of the ___migrate field from metatable
for the userdata at position \c i.
*/
lua_migrate_fn get_migrate_fn(lua_State * L, int i) {
if (lua_getmetatable(L, i)) {
lua_getfield(L, -1, "___migrate");
if (lua_islightuserdata(L, -1)) {
lua_migrate_fn r = reinterpret_cast<lua_migrate_fn>(lua_touserdata(L, -1));
lua_pop(L, 2);
return r;
}
lua_pop(L, 2);
}
return nullptr;
}
}