src/binaryen/src/support/utilities.h

   1 /*
   2  * Copyright 2016 WebAssembly Community Group participants
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef wasm_support_utilities_h
  18 #define wasm_support_utilities_h
  19
  20 #include "compiler-support.h"
  21
  22 #include <cassert>
  23 #include <cstdint>
  24 #include <cstring>
  25 #include <memory>
  26 #include <iostream>
  27 #include <type_traits>
  28
  29 namespace wasm {
  30
  31 // Type punning needs to be done through this function to avoid undefined
  32 // behavior: unions and reinterpret_cast aren't valid approaches.
  33 template <class Destination, class Source>
  34 inline Destination bit_cast(const Source& source) {
  35   static_assert(sizeof(Destination) == sizeof(Source),
  36                 "bit_cast needs to be between types of the same size");
  37   static_assert(std::is_pod<Destination>::value, "non-POD bit_cast undefined");
  38   static_assert(std::is_pod<Source>::value, "non-POD bit_cast undefined");
  39   Destination destination;
  40   std::memcpy(&destination, &source, sizeof(destination));
  41   return destination;
  42 }
  43
  44 inline bool isPowerOf2(uint32_t v) {
  45   return v && !(v & (v - 1));
  46 }
  47
  48 inline size_t alignAddr(size_t address, size_t alignment) {
  49   assert(alignment && isPowerOf2((uint32_t)alignment) &&
  50          "Alignment is not a power of two!");
  51
  52   assert(address + alignment - 1 >= address);
  53
  54   return ((address + alignment - 1) & ~(alignment - 1));
  55 }
  56
  57 template<typename T, typename... Args>
  58 std::unique_ptr<T> make_unique(Args&&... args)
  59 {
  60     return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
  61 }
  62
  63 // For fatal errors which could arise from input (i.e. not assertion failures)
  64 class Fatal {
  65  public:
  66   Fatal() {
  67     std::cerr << "Fatal: ";
  68   }
  69   template<typename T>
  70   Fatal &operator<<(T arg) {
  71     std::cerr << arg;
  72     return *this;
  73   }
  74   WASM_NORETURN ~Fatal() {
  75     std::cerr << "\n";
  76     exit(1);
  77   }
  78 };
  79
  80
  81 }  // namespace wasm
  82
  83 #endif   // wasm_support_utilities_h