include/llvm/LinkAllIR.h

   1 //===----- LinkAllIR.h - Reference All VMCore Code --------------*- C++ -*-===//
   2 //
   3 //                      The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This header file pulls in all the object modules of the VMCore library so
  11 // that tools like llc, opt, and lli can ensure they are linked with all symbols
  12 // from libVMCore.a It should only be used from a tool's main program.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #ifndef LLVM_LINKALLIR_H
  17 #define LLVM_LINKALLIR_H
  18
  19 #include "llvm/BinaryFormat/Dwarf.h"
  20 #include "llvm/IR/InlineAsm.h"
  21 #include "llvm/IR/Instructions.h"
  22 #include "llvm/IR/LLVMContext.h"
  23 #include "llvm/IR/Module.h"
  24 #include "llvm/IR/Verifier.h"
  25 #include "llvm/Support/DynamicLibrary.h"
  26 #include "llvm/Support/MathExtras.h"
  27 #include "llvm/Support/Memory.h"
  28 #include "llvm/Support/Mutex.h"
  29 #include "llvm/Support/Path.h"
  30 #include "llvm/Support/Process.h"
  31 #include "llvm/Support/Program.h"
  32 #include "llvm/Support/Signals.h"
  33 #include <cstdlib>
  34
  35 namespace {
  36   struct ForceVMCoreLinking {
  37     ForceVMCoreLinking() {
  38       // We must reference VMCore in such a way that compilers will not
  39       // delete it all as dead code, even with whole program optimization,
  40       // yet is effectively a NO-OP. As the compiler isn't smart enough
  41       // to know that getenv() never returns -1, this will do the job.
  42       if (std::getenv("bar") != (char*) -1)
  43         return;
  44       llvm::LLVMContext Context;
  45       (void)new llvm::Module("", Context);
  46       (void)new llvm::UnreachableInst(Context);
  47       (void)    llvm::createVerifierPass();
  48     }
  49   } ForceVMCoreLinking;
  50 }
  51
  52 #endif