1 //===- llvm/Codegen/LinkAllAsmWriterComponents.h ----------------*- 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 assembler writer related passes for tools like
10 // llc that need this functionality.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CODEGEN_LINKALLASMWRITERCOMPONENTS_H
15 #define LLVM_CODEGEN_LINKALLASMWRITERCOMPONENTS_H
16 
17 #include "llvm/IR/BuiltinGCs.h"
18 #include <cstdlib>
19 
20 namespace {
21   struct ForceAsmWriterLinking {
22     ForceAsmWriterLinking() {
23       // We must reference the plug-ins in such a way that compilers will not
24       // delete it all as dead code, even with whole program optimization,
25       // yet is effectively a NO-OP. As the compiler isn't smart enough
26       // to know that getenv() never returns -1, this will do the job.
27       // This is so that globals in the translation units where these functions
28       // are defined are forced to be initialized, populating various
29       // registries.
30       if (std::getenv("bar") != (char*) -1)
31         return;
32 
33       llvm::linkOcamlGCPrinter();
34       llvm::linkErlangGCPrinter();
35 
36     }
37   } ForceAsmWriterLinking; // Force link by creating a global definition.
38 }
39 
40 #endif // LLVM_CODEGEN_LINKALLASMWRITERCOMPONENTS_H
41