Initial import

external/socket/src/except.c

@@ -0,0 +1,129 @@
+/*=========================================================================*\
+* Simple exception support
+* LuaSocket toolkit
+\*=========================================================================*/
+#include "luasocket.h"
+#include "except.h"
+#include <stdio.h>
+
+#if LUA_VERSION_NUM < 502
+#define lua_pcallk(L, na, nr, err, ctx, cont) \
+    (((void)ctx),((void)cont),lua_pcall(L, na, nr, err))
+#endif
+
+#if LUA_VERSION_NUM < 503
+typedef int lua_KContext;
+#endif
+
+/*=========================================================================*\
+* Internal function prototypes.
+\*=========================================================================*/
+static int global_protect(lua_State *L);
+static int global_newtry(lua_State *L);
+static int protected_(lua_State *L);
+static int finalize(lua_State *L);
+static int do_nothing(lua_State *L);
+
+/* except functions */
+static luaL_Reg func[] = {
+    {"newtry",    global_newtry},
+    {"protect",   global_protect},
+    {NULL,        NULL}
+};
+
+/*-------------------------------------------------------------------------*\
+* Try factory
+\*-------------------------------------------------------------------------*/
+static void wrap(lua_State *L) {
+    lua_createtable(L, 1, 0);
+    lua_pushvalue(L, -2);
+    lua_rawseti(L, -2, 1);
+    lua_pushvalue(L, lua_upvalueindex(1));
+    lua_setmetatable(L, -2);
+}
+
+static int finalize(lua_State *L) {
+    if (!lua_toboolean(L, 1)) {
+        lua_pushvalue(L, lua_upvalueindex(2));
+        lua_call(L, 0, 0);
+        lua_settop(L, 2);
+        wrap(L);
+        lua_error(L);
+        return 0;
+    } else return lua_gettop(L);
+}
+
+static int do_nothing(lua_State *L) {
+    (void) L;
+    return 0;
+}
+
+static int global_newtry(lua_State *L) {
+    lua_settop(L, 1);
+    if (lua_isnil(L, 1)) lua_pushcfunction(L, do_nothing);
+    lua_pushvalue(L, lua_upvalueindex(1));
+    lua_insert(L, -2);
+    lua_pushcclosure(L, finalize, 2);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Protect factory
+\*-------------------------------------------------------------------------*/
+static int unwrap(lua_State *L) {
+    if (lua_istable(L, -1) && lua_getmetatable(L, -1)) {
+        int r = lua_rawequal(L, -1, lua_upvalueindex(1));
+        lua_pop(L, 1);
+        if (r) {
+            lua_pushnil(L);
+            lua_rawgeti(L, -2, 1);
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int protected_finish(lua_State *L, int status, lua_KContext ctx) {
+    (void)ctx;
+    if (status != 0 && status != LUA_YIELD) {
+        if (unwrap(L)) return 2;
+        else return lua_error(L);
+    } else return lua_gettop(L);
+}
+
+#if LUA_VERSION_NUM == 502
+static int protected_cont(lua_State *L) {
+    int ctx = 0;
+    int status = lua_getctx(L, &ctx);
+    return protected_finish(L, status, ctx);
+}
+#else
+#define protected_cont protected_finish
+#endif
+
+static int protected_(lua_State *L) {
+    int status;
+    lua_pushvalue(L, lua_upvalueindex(2));
+    lua_insert(L, 1);
+    status = lua_pcallk(L, lua_gettop(L) - 1, LUA_MULTRET, 0, 0, protected_cont);
+    return protected_finish(L, status, 0);
+}
+
+static int global_protect(lua_State *L) {
+    lua_settop(L, 1);
+    lua_pushvalue(L, lua_upvalueindex(1));
+    lua_insert(L, 1);
+    lua_pushcclosure(L, protected_, 2);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Init module
+\*-------------------------------------------------------------------------*/
+int except_open(lua_State *L) {
+    lua_newtable(L); /* metatable for wrapped exceptions */
+    lua_pushboolean(L, 0);
+    lua_setfield(L, -2, "__metatable");
+    luaL_setfuncs(L, func, 1);
+    return 0;
+}