- //===----- LinkAllIR.h - Reference All VMCore Code --------------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This header file pulls in all the object modules of the VMCore library so 
- // that tools like llc, opt, and lli can ensure they are linked with all symbols 
- // from libVMCore.a It should only be used from a tool's main program. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_LINKALLIR_H 
- #define LLVM_LINKALLIR_H 
-   
- #include "llvm/BinaryFormat/Dwarf.h" 
- #include "llvm/IR/InlineAsm.h" 
- #include "llvm/IR/Instructions.h" 
- #include "llvm/IR/LLVMContext.h" 
- #include "llvm/IR/Module.h" 
- #include "llvm/IR/Verifier.h" 
- #include "llvm/Support/DynamicLibrary.h" 
- #include "llvm/Support/MathExtras.h" 
- #include "llvm/Support/Memory.h" 
- #include "llvm/Support/Mutex.h" 
- #include "llvm/Support/Path.h" 
- #include "llvm/Support/Process.h" 
- #include "llvm/Support/Program.h" 
- #include "llvm/Support/Signals.h" 
- #include <cstdlib> 
-   
- namespace { 
-   struct ForceVMCoreLinking { 
-     ForceVMCoreLinking() { 
-       // We must reference VMCore in such a way that compilers will not 
-       // delete it all as dead code, even with whole program optimization, 
-       // yet is effectively a NO-OP. As the compiler isn't smart enough 
-       // to know that getenv() never returns -1, this will do the job. 
-       // This is so that globals in the translation units where these functions 
-       // are defined are forced to be initialized, populating various 
-       // registries. 
-       if (std::getenv("bar") != (char*) -1) 
-         return; 
-       llvm::LLVMContext Context; 
-       (void)new llvm::Module("", Context); 
-       (void)new llvm::UnreachableInst(Context); 
-       (void)    llvm::createVerifierPass(); 
-     } 
-   } ForceVMCoreLinking; 
- } 
-   
- #endif 
-