/* * Copyright 2016 WebAssembly Community Group participants * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef wasm_support_utilities_h #define wasm_support_utilities_h #include "compiler-support.h" #include #include #include #include #include #include #include "support/bits.h" namespace wasm { // Type punning needs to be done through this function to avoid undefined // behavior: unions and reinterpret_cast aren't valid approaches. template inline Destination bit_cast(const Source& source) { static_assert(sizeof(Destination) == sizeof(Source), "bit_cast needs to be between types of the same size"); static_assert(std::is_pod::value, "non-POD bit_cast undefined"); static_assert(std::is_pod::value, "non-POD bit_cast undefined"); Destination destination; std::memcpy(&destination, &source, sizeof(destination)); return destination; } inline size_t alignAddr(size_t address, size_t alignment) { assert(alignment && Bits::isPowerOf2((uint32_t)alignment) && "Alignment is not a power of two!"); assert(address + alignment - 1 >= address); return ((address + alignment - 1) & ~(alignment - 1)); } template std::unique_ptr make_unique(Args&&... args) { return std::unique_ptr(new T(std::forward(args)...)); } // For fatal errors which could arise from input (i.e. not assertion failures) class Fatal { public: Fatal() { std::cerr << "Fatal: "; } template Fatal& operator<<(T arg) { std::cerr << arg; return *this; } WASM_NORETURN ~Fatal() { std::cerr << "\n"; // Use _Exit here to avoid calling static destructors. This avoids deadlocks // in (for example) the thread worker pool, where workers hold a lock while // performing their work. _Exit(1); } }; WASM_NORETURN void handle_unreachable(const char* msg = nullptr, const char* file = nullptr, unsigned line = 0); // If control flow reaches the point of the WASM_UNREACHABLE(), the program is // undefined. #ifndef NDEBUG #define WASM_UNREACHABLE(msg) wasm::handle_unreachable(msg, __FILE__, __LINE__) #elif defined(WASM_BUILTIN_UNREACHABLE) #define WASM_UNREACHABLE(msg) WASM_BUILTIN_UNREACHABLE #else #define WASM_UNREACHABLE(msg) wasm::handle_unreachable() #endif } // namespace wasm #endif // wasm_support_utilities_h