include/llvm/LinkAllIR.h

   1 //===----- LinkAllIR.h - Reference All VMCore Code --------------*- 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 header file pulls in all the object modules of the VMCore library so
  10 // that tools like llc, opt, and lli can ensure they are linked with all symbols
  11 // from libVMCore.a It should only be used from a tool's main program.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_LINKALLIR_H
  16 #define LLVM_LINKALLIR_H
  17
  18 #include "llvm/BinaryFormat/Dwarf.h"
  19 #include "llvm/IR/InlineAsm.h"
  20 #include "llvm/IR/Instructions.h"
  21 #include "llvm/IR/LLVMContext.h"
  22 #include "llvm/IR/Module.h"
  23 #include "llvm/IR/Verifier.h"
  24 #include "llvm/Support/DynamicLibrary.h"
  25 #include "llvm/Support/MathExtras.h"
  26 #include "llvm/Support/Memory.h"
  27 #include "llvm/Support/Mutex.h"
  28 #include "llvm/Support/Path.h"
  29 #include "llvm/Support/Process.h"
  30 #include "llvm/Support/Program.h"
  31 #include "llvm/Support/Signals.h"
  32 #include <cstdlib>
  33
  34 namespace {
  35   struct ForceVMCoreLinking {
  36     ForceVMCoreLinking() {
  37       // We must reference VMCore in such a way that compilers will not
  38       // delete it all as dead code, even with whole program optimization,
  39       // yet is effectively a NO-OP. As the compiler isn't smart enough
  40       // to know that getenv() never returns -1, this will do the job.
  41       if (std::getenv("bar") != (char*) -1)
  42         return;
  43       llvm::LLVMContext Context;
  44       (void)new llvm::Module("", Context);
  45       (void)new llvm::UnreachableInst(Context);
  46       (void)    llvm::createVerifierPass();
  47     }
  48   } ForceVMCoreLinking;
  49 }
  50
  51 #endif