diff options
| -rw-r--r-- | indra/newview/llluamanager.cpp | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/indra/newview/llluamanager.cpp b/indra/newview/llluamanager.cpp index 1a1732aa5e..c4603e493c 100644 --- a/indra/newview/llluamanager.cpp +++ b/indra/newview/llluamanager.cpp @@ -49,6 +49,8 @@ extern "C" #include "lua/lualib.h" } +#include <cstring> // std::memcpy() + #if LL_WINDOWS #pragma comment(lib, "liblua54.a") #endif @@ -303,3 +305,251 @@ void LLLUAmanager::runScriptOnLogin() runScriptFile(filename); } + +std::string lua_tostdstring(lua_State* L, int index) +{ + size_t len; + const char* strval{ lua_tolstring(L, index, &len) }; + return { strval, len }; +} + +// By analogy with existing lua_tomumble() functions, return an LLSD object +// corresponding to the Lua object at stack index 'index' in state L. +// This function assumes that a Lua caller is fully aware that they're trying +// to call a viewer function. In other words, the caller must specifically +// construct Lua data convertible to LLSD. +LLSD lua_tollsd(lua_State* L, int index) +{ + switch (lua_type(L, index)) + { + case LUA_TNONE: + case LUA_TNIL: + return {}; + + case LUA_TBOOLEAN: + return bool(lua_toboolean(L, index)); + + case LUA_TNUMBER: + { + // check if integer truncation leaves the number intact + lua_Integer intval{ lua_tointeger(L, index) }; + lua_Number numval{ lua_tonumber(L, index) }; + if (lua_Number(intval) == numval) + { + return intval; + } + else + { + return numval; + } + } + + case LUA_TSTRING: + return lua_tostdstring(L, index); + + case LUA_TUSERDATA: + { + LLSD::Binary binary(lua_objlen(L, index)); + std::memcpy(binary.data(), lua_touserdata(L, index), binary.size()); + return binary; + } + + case LUA_TTABLE: + { + // A Lua table correctly constructed to convert to LLSD will have + // either consecutive integer keys starting at 1, which we represent + // as an LLSD array (with Lua index 1 at C++ index 0), or will have + // all string keys. + // Possible looseness could include: + // - All integer keys >= 1, but with "holes," could produce an LLSD + // array with isUndefined() entries at unspecified keys. We could + // specify a maximum size of allowable gap, and throw an error if a + // gap exceeds that size. + // - A mix of integer and string keys could produce an LLSD map in + // which the integer keys are converted to string. (Key conversion + // must be performed in C++, not Lua, to avoid confusing + // lua_next().) + // - However, since in Lua t[0] and t["0"] are distinct table entries, + // do not consider converting numeric string keys to int to return + // an LLSD array. + // But until we get more experience with actual Lua scripts in + // practice, let's say that any deviation is a Lua coding error. + // An important property of the strict definition above is that most + // conforming data blobs can make a round trip across the language + // boundary and still compare equal. A non-conforming data blob would + // lose that property. + // Known exceptions to round trip identity: + // - Empty LLSD map and empty LLSD array convert to empty Lua table. + // But empty Lua table converts to isUndefined() LLSD object. + // - LLSD::Real with integer value returns as LLSD::Integer. + // - LLSD::UUID, LLSD::Date and LLSD::URI all convert to Lua string, + // and so return as LLSD::String. + lua_pushnil(L); // first key + if (! lua_next(L, index)) + { + // it's a table, but the table is empty -- no idea if it should be + // modeled as empty array or empty map -- return isUndefined(), + // which can be consumed as either + return {}; + } + // key is at index -2, value at index -1 + // from here until lua_next() returns 0, have to lua_pop(2) if we + // return early + // Remember the type of the first key + auto firstkeytype{ lua_type(L, -2) }; + switch (firstkeytype) + { + case LUA_TNUMBER: + { + LLSD result{ LLSD::emptyArray() }; + // right away expand the result array to the size we'll need + result[lua_objlen(L, index) - 1] = LLSD(); + // track the consecutive indexes we require + LLSD::Integer expected_index{ 0 }; + do + { + auto arraykeytype{ lua_type(L, -2) }; + switch (arraykeytype) + { + case LUA_TNUMBER: + { + lua_Number actual_index{ lua_tonumber(L, -2) }; + if (actual_index != lua_Number(++expected_index)) + { + // key isn't consecutive starting at 1 (may not even be an + // integer) - this doesn't fit our LLSD array constraints + lua_pop(L, 2); + return luaL_error(L, "Expected array key %d, got %f instead", + int(expected_index), actual_index); + } + + result.append(lua_tollsd(L, -1)); + break; + } + + case LUA_TSTRING: + // break out strings specially to report the value + lua_pop(L, 2); + return luaL_error(L, "Cannot convert string array key '%s' to LLSD", + lua_tostring(L, -2)); + + default: + lua_pop(L, 2); + return luaL_error(L, "Cannot convert %s array key to LLSD", + lua_typename(L, arraykeytype)); + } + + // remove value, keep key for next iteration + lua_pop(L, 1); + } while (lua_next(L, index) != 0); + return result; + } + + case LUA_TSTRING: + { + LLSD result{ LLSD::emptyMap() }; + do + { + auto mapkeytype{ lua_type(L, -2) }; + if (mapkeytype != LUA_TSTRING) + { + lua_pop(L, 2); + return luaL_error(L, "Cannot convert %s map key to LLSD", + lua_typename(L, mapkeytype)); + } + + result[lua_tostdstring(L, -2)] = lua_tollsd(L, -1); + // remove value, keep key for next iteration + lua_pop(L, 1); + } while (lua_next(L, index) != 0); + return result; + } + + default: + lua_pop(L, 2); + return luaL_error(L, "Cannot convert %s table key to LLSD", + lua_typename(L, firstkeytype)); + } + } + + default: + // Other Lua entities (e.g. function, C function, light userdata, + // thread, userdata) are not convertible to LLSD, indicating a coding + // error in the caller. + return luaL_error(L, "Cannot convert type %s to LLSD", + lua_typename(L, lua_type(L, index))); + } +} + +// By analogy with existing lua_pushmumble() functions, push onto state L's +// stack a Lua object corresponding to the passed LLSD object. +int lua_pushllsd(lua_State* L, const LLSD& data) +{ + switch (data.type()) + { + case LLSD::TypeUndefined: + lua_pushnil(L); + break; + + case LLSD::TypeBoolean: + lua_pushboolean(L, data.asBoolean()); + break; + + case LLSD::TypeInteger: + lua_pushinteger(L, data.asInteger()); + break; + + case LLSD::TypeReal: + lua_pushnumber(L, data.asReal()); + break; + + case LLSD::TypeBinary: + { + auto binary{ data.asBinary() }; + std::memcpy(lua_newuserdata(L, binary.size()), binary.data(), binary.size()); + break; + } + + case LLSD::TypeMap: + { + // push a new table with space for our non-array keys + lua_createtable(L, 0, data.size()); + for (const auto& pair: llsd::inMap(data)) + { + // push value -- so now table is at -2, value at -1 + lua_pushllsd(L, pair.second); + // pop value, assign to table[key] + lua_setfield(L, -2, pair.first.c_str()); + } + break; + } + + case LLSD::TypeArray: + { + // push a new table with space for array entries + lua_createtable(L, data.size(), 0); + lua_Integer index{ 0 }; + for (const auto& item: llsd::inArray(data)) + { + // push new index value: table at -2, index at -1 + lua_pushinteger(L, ++index); + // push new array value: table at -3, index at -2, value at -1 + lua_pushllsd(L, item); + // pop key and value, assign table[key] = value + lua_settable(L, -3); + } + break; + } + + case LLSD::TypeString: + case LLSD::TypeUUID: + case LLSD::TypeDate: + case LLSD::TypeURI: + default: + { + auto strdata{ data.asString() }; + lua_pushlstring(L, strdata.c_str(), strdata.length()); + break; + } + } +} |