Extract some common ffi API stuff

build/libaegisub/libaegisub.vcxproj

@@ -93,6 +93,7 @@
     <ClInclude Include="$(SrcDir)include\libaegisub\line_iterator.h" />
     <ClInclude Include="$(SrcDir)include\libaegisub\line_wrap.h" />
     <ClInclude Include="$(SrcDir)include\libaegisub\log.h" />
+    <ClInclude Include="$(SrcDir)include\libaegisub\lua\ffi.h" />
     <ClInclude Include="$(SrcDir)include\libaegisub\lua\modules.h" />
     <ClInclude Include="$(SrcDir)include\libaegisub\lua\script_reader.h" />
     <ClInclude Include="$(SrcDir)include\libaegisub\lua\utils.h" />

build/libaegisub/libaegisub.vcxproj.filters

@@ -203,6 +203,9 @@
     <ClInclude Include="$(SrcDir)lua\modules\lpeg.h">
       <Filter>Lua\Modules</Filter>
     </ClInclude>
+    <ClInclude Include="$(SrcDir)include\libaegisub\lua\ffi.h">
+      <Filter>Lua</Filter>
+    </ClInclude>
     <ClInclude Include="$(SrcDir)include\libaegisub\lua\modules.h">
       <Filter>Lua</Filter>
     </ClInclude>

libaegisub/include/libaegisub/lua/ffi.h

@@ -0,0 +1,62 @@
+// 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/type_name.h>
+
+#include <lua.hpp>
+
+namespace agi { namespace lua {
+static void register_lib_functions(lua_State *) {
+	// Base case of recursion; nothing to do
+}
+
+template<typename Func, typename... Rest>
+void register_lib_functions(lua_State *L, const char *name, Func *func, Rest... rest) {
+	lua_pushvalue(L, -2); // push cast function
+	lua_pushstring(L, type_name<Func*>::name().c_str());
+	// This cast isn't legal, but LuaJIT internally requires that it work, so we can rely on it too
+	lua_pushlightuserdata(L, (void *)func);
+	lua_call(L, 2, 1);
+	lua_setfield(L, -2, name);
+
+	register_lib_functions(L, rest...);
+}
+
+template<typename... Args>
+void register_lib_table(lua_State *L, std::initializer_list<const char *> types, Args... functions) {
+	static_assert((sizeof...(functions) & 1) == 0, "Functions must be alternating names and function pointers");
+
+	lua_getglobal(L, "require");
+	lua_pushstring(L, "ffi");
+	lua_call(L, 1, 1);
+
+	// Register all passed type with the ffi
+	for (auto type : types) {
+		lua_getfield(L, -1, "cdef");
+		lua_pushfstring(L, "typedef struct %s %s;", type, type);
+		lua_call(L, 1, 0);
+	}
+
+	lua_getfield(L, -1, "cast");
+	lua_remove(L, -2); // ffi table
+
+	lua_createtable(L, 0, sizeof...(functions) / 2);
+	register_lib_functions(L, functions...);
+	lua_remove(L, -2); // ffi.cast function
+	// Leaves lib table on the stack
+}
+
+} }

libaegisub/lua/modules/lfs.cpp

@@ -15,11 +15,10 @@
 // Aegisub Project http://www.aegisub.org/
 
 #include "libaegisub/fs.h"
-#include "libaegisub/type_name.h"
+#include "libaegisub/lua/ffi.h"
 
 #include <boost/filesystem/operations.hpp>
 #include <boost/filesystem/path.hpp>
-#include <lua.hpp>
 
 using namespace agi::fs;
 namespace bfs = boost::filesystem;
@@ -121,45 +120,21 @@ time_t get_mtime(const char *path, char **err) {
 uintmax_t get_size(const char *path, char **err) {
 	return wrap(err, [=] { return Size(path); });
 }
-
-template<typename T>
-void push_ffi_function(lua_State *L, const char *name, T *func) {
-	lua_pushvalue(L, -2); // push cast function
-	lua_pushstring(L, agi::type_name<T*>::name().c_str());
-	// This cast isn't legal, but LuaJIT internally requires that it work
-	lua_pushlightuserdata(L, (void *)func);
-	lua_call(L, 2, 1);
-	lua_setfield(L, -2, name);
-}
 }
 
 extern "C" int luaopen_lfs_impl(lua_State *L) {
-	lua_getglobal(L, "require");
-	lua_pushstring(L, "ffi");
-	lua_call(L, 1, 1);
-
-	lua_getfield(L, -1, "cdef");
-	lua_pushstring(L, "typedef struct DirectoryIterator DirectoryIterator;");
-	lua_call(L, 1, 0);
-
-	lua_getfield(L, -1, "cast");
-	lua_remove(L, -2); // ffi table
-
-	lua_createtable(L, 0, 12);
-	push_ffi_function(L, "chdir", lfs_chdir);
-	push_ffi_function(L, "currentdir", currentdir);
-	push_ffi_function(L, "mkdir", mkdir);
-	push_ffi_function(L, "rmdir", lfs_rmdir);
-	push_ffi_function(L, "touch", touch);
-	push_ffi_function(L, "get_mtime", get_mtime);
-	push_ffi_function(L, "get_mode", get_mode);
-	push_ffi_function(L, "get_size", get_size);
-
-	push_ffi_function(L, "dir_new", dir_new);
-	push_ffi_function(L, "dir_free", dir_free);
-	push_ffi_function(L, "dir_next", dir_next);
-	push_ffi_function(L, "dir_close", dir_close);
-
-	lua_remove(L, -2); // ffi.cast function
+	agi::lua::register_lib_table(L, {"DirectoryIterator"},
+		"chdir", lfs_chdir,
+		"currentdir", currentdir,
+		"mkdir", mkdir,
+		"rmdir", lfs_rmdir,
+		"touch", touch,
+		"get_mtime", get_mtime,
+		"get_mode", get_mode,
+		"get_size", get_size,
+		"dir_new", dir_new,
+		"dir_free", dir_free,
+		"dir_next", dir_next,
+		"dir_close", dir_close);
 	return 1;
 }

libaegisub/lua/modules/unicode.cpp

@@ -14,22 +14,11 @@
 //
 // Aegisub Project http://www.aegisub.org/
 
-#include <libaegisub/type_name.h>
+#include <libaegisub/lua/ffi.h>
 
 #include <boost/locale/conversion.hpp>
-#include <lua.hpp>
 
 namespace {
-template<typename T>
-void push_ffi_function(lua_State *L, const char *name, T *func) {
-	lua_pushvalue(L, -2); // push cast function
-	lua_pushstring(L, agi::type_name<T*>::name().c_str());
-	// This cast isn't legal, but LuaJIT internally requires that it work
-	lua_pushlightuserdata(L, (void *)func);
-	lua_call(L, 2, 1);
-	lua_setfield(L, -2, name);
-}
-
 template<std::string (*func)(const char *, std::locale const&)>
 char *wrap(const char *str, char **err) {
 	try {
@@ -42,17 +31,9 @@ char *wrap(const char *str, char **err) {
 }
 
 extern "C" int luaopen_unicode_impl(lua_State *L) {
-	lua_getglobal(L, "require");
-	lua_pushstring(L, "ffi");
-	lua_call(L, 1, 1);
-	lua_getfield(L, -1, "cast");
-	lua_remove(L, -2); // ffi table
-
-	lua_createtable(L, 0, 3);
-	push_ffi_function(L, "to_upper_case", wrap<boost::locale::to_upper<char>>);
-	push_ffi_function(L, "to_lower_case", wrap<boost::locale::to_lower<char>>);
-	push_ffi_function(L, "to_fold_case", wrap<boost::locale::fold_case<char>>);
-
-	lua_remove(L, -2); // ffi.cast function
+	agi::lua::register_lib_table(L, {},
+		"to_upper_case", wrap<boost::locale::to_upper<char>>,
+		"to_lower_case", wrap<boost::locale::to_lower<char>>,
+		"to_fold_case", wrap<boost::locale::fold_case<char>>);
 	return 1;
 }