1 //===-- ThreadSafeModule.cpp - Thread safe Module, Context, and Utilities h-===//
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 #include "llvm/ExecutionEngine/Orc/ThreadSafeModule.h"
11 #include "llvm/Bitcode/BitcodeReader.h"
12 #include "llvm/Bitcode/BitcodeWriter.h"
13 #include "llvm/Transforms/Utils/Cloning.h"
14 
15 namespace llvm {
16 namespace orc {
17 
18 ThreadSafeModule cloneToNewContext(ThreadSafeModule &TSM,
19                                    GVPredicate ShouldCloneDef,
20                                    GVModifier UpdateClonedDefSource) {
21   assert(TSM && "Can not clone null module");
22 
23   if (!ShouldCloneDef)
24     ShouldCloneDef = [](const GlobalValue&) { return true; };
25 
26   auto Lock = TSM.getContextLock();
27 
28   SmallVector<char, 1> ClonedModuleBuffer;
29 
30   {
31     std::vector<GlobalValue *> ClonedDefsInSrc;
32     ValueToValueMapTy VMap;
33     auto Tmp = CloneModule(*TSM.getModule(), VMap,
34                            [&](const GlobalValue *GV) {
35       if (ShouldCloneDef(*GV)) {
36         ClonedDefsInSrc.push_back(const_cast<GlobalValue *>(GV));
37         return true;
38       }
39       return false;
40     });
41 
42     if (UpdateClonedDefSource)
43       for (auto *GV : ClonedDefsInSrc)
44         UpdateClonedDefSource(*GV);
45 
46     BitcodeWriter BCWriter(ClonedModuleBuffer);
47 
48     BCWriter.writeModule(*Tmp);
49     BCWriter.writeSymtab();
50     BCWriter.writeStrtab();
51   }
52 
53   MemoryBufferRef ClonedModuleBufferRef(
54       StringRef(ClonedModuleBuffer.data(), ClonedModuleBuffer.size()),
55       "cloned module buffer");
56   ThreadSafeContext NewTSCtx(llvm::make_unique<LLVMContext>());
57 
58   auto ClonedModule =
59       cantFail(parseBitcodeFile(ClonedModuleBufferRef, *NewTSCtx.getContext()));
60   ClonedModule->setModuleIdentifier(TSM.getModule()->getName());
61   return ThreadSafeModule(std::move(ClonedModule), std::move(NewTSCtx));
62 }
63 
64 } // end namespace orc
65 } // end namespace llvm
66