Aegisub/libaegisub/lua/script_reader.cpp
Thomas Goyne 9492192b73 Switch back to building Lua as C
In preparation for switching to LuaJIT, which doesn't support PUC Lua's
thing of using C++ exceptions for lua_error.

Requires replacing all uses of lua_error (and things calling lua_error)
with custom versions that throw an exception instead and adding an
exception -> lua error wrapper at all C++ -> Lua boundaries.
2014-04-27 10:37:23 -07:00

146 lines
4.7 KiB
C++

// Copyright (c) 2014, Thomas Goyne <plorkyeran@aegisub.org>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
// Aegisub Project http://www.aegisub.org/
#include "libaegisub/lua/script_reader.h"
#include "libaegisub/file_mapping.h"
#include "libaegisub/log.h"
#include "libaegisub/lua/utils.h"
#include <boost/algorithm/string/replace.hpp>
#include <boost/tokenizer.hpp>
#include <lauxlib.h>
namespace agi { namespace lua {
bool LoadFile(lua_State *L, agi::fs::path const& raw_filename) {
auto filename = raw_filename;
try {
filename = agi::fs::Canonicalize(raw_filename);
}
catch (agi::fs::FileSystemUnknownError const& e) {
LOG_E("auto4/lua") << "Error canonicalizing path: " << e.GetChainedMessage();
}
agi::read_file_mapping file(filename);
auto buff = file.read();
size_t size = static_cast<size_t>(file.size());
// Discard the BOM if present
if (size >= 3 && buff[0] == -17 && buff[1] == -69 && buff[2] == -65) {
buff += 3;
size -= 3;
}
if (!agi::fs::HasExtension(filename, "moon"))
return luaL_loadbuffer(L, buff, size, filename.string().c_str()) == 0;
// We have a MoonScript file, so we need to load it with that
// It might be nice to have a dedicated lua state for compiling
// MoonScript to Lua
if (luaL_dostring(L, "return require('moonscript').loadstring"))
return false; // Leaves error message on stack
// Save the text we'll be loading for the line number rewriting in the
// error handling
lua_pushlstring(L, buff, size);
lua_pushvalue(L, -1);
lua_setfield(L, LUA_REGISTRYINDEX, ("raw moonscript: " + filename.string()).c_str());
push_value(L, filename);
if (lua_pcall(L, 2, 2, 0))
return false; // Leaves error message on stack
// loadstring returns nil, error on error or a function on success
if (lua_isnil(L, 1)) {
lua_remove(L, 1);
return false;
}
lua_pop(L, 1); // Remove the extra nil for the stackchecker
return true;
}
static int module_loader(lua_State *L) {
int pretop = lua_gettop(L);
std::string module(check_string(L, -1));
boost::replace_all(module, ".", LUA_DIRSEP);
// Get the lua package include path (which the user may have modified)
lua_getglobal(L, "package");
lua_getfield(L, -1, "path");
std::string package_paths(check_string(L, -1));
lua_pop(L, 2);
boost::char_separator<char> sep(";");
for (auto filename : boost::tokenizer<boost::char_separator<char>>(package_paths, sep)) {
boost::replace_all(filename, "?", module);
// If there's a .moon file at that path, load it instead of the
// .lua file
agi::fs::path path = filename;
if (agi::fs::HasExtension(path, "lua")) {
agi::fs::path moonpath = path;
moonpath.replace_extension("moon");
if (agi::fs::FileExists(moonpath))
path = moonpath;
}
try {
if (!LoadFile(L, path))
return error(L, "Error loading Lua module \"%s\":\n%s", path.string().c_str(), check_string(L, 1).c_str());
break;
}
catch (agi::fs::FileNotFound const&) {
// Not an error so swallow and continue on
}
catch (agi::fs::NotAFile const&) {
// Not an error so swallow and continue on
}
catch (agi::Exception const& e) {
return error(L, "Error loading Lua module \"%s\":\n%s", path.string().c_str(), e.GetChainedMessage().c_str());
}
}
return lua_gettop(L) - pretop;
}
void Install(lua_State *L, std::vector<fs::path> const& include_path) {
// set the module load path to include_path
lua_getglobal(L, "package");
push_value(L, "path");
#ifdef _WIN32
// No point in checking any of the default locations on Windows since
// there won't be anything there
push_value(L, "");
#else
push_value(L, "path");
lua_gettable(L, -3);
#endif
for (auto const& path : include_path) {
lua_pushfstring(L, ";%s/?.lua;%s/?/init.lua", path.string().c_str(), path.string().c_str());
lua_concat(L, 2);
}
lua_settable(L, -3);
// Replace the default lua module loader with our unicode compatible one
lua_getfield(L, -1, "loaders");
push_value(L, exception_wrapper<module_loader>);
lua_rawseti(L, -2, 2);
lua_pop(L, 2);
}
} }