include/llvm/ExecutionEngine/MCJIT.h

   1 //===-- MCJIT.h - MC-Based Just-In-Time Execution Engine --------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file forces the MCJIT to link in on certain operating systems.
  10 // (Windows).
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_EXECUTIONENGINE_MCJIT_H
  15 #define LLVM_EXECUTIONENGINE_MCJIT_H
  16
  17 #include "llvm/ExecutionEngine/ExecutionEngine.h"
  18 #include <cstdlib>
  19
  20 extern "C" void LLVMLinkInMCJIT();
  21
  22 namespace {
  23   struct ForceMCJITLinking {
  24     ForceMCJITLinking() {
  25       // We must reference MCJIT in such a way that compilers will not
  26       // delete it all as dead code, even with whole program optimization,
  27       // yet is effectively a NO-OP. As the compiler isn't smart enough
  28       // to know that getenv() never returns -1, this will do the job.
  29       if (std::getenv("bar") != (char*) -1)
  30         return;
  31
  32       LLVMLinkInMCJIT();
  33     }
  34   } ForceMCJITLinking;
  35 }
  36
  37 #endif