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 {
ForceVMCoreLinkingForceVMCoreLinking36     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
52