1 //===- llvm-link.cpp - Low-level LLVM linker ------------------------------===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This utility may be invoked in the following manner:
10 //  llvm-link a.bc b.bc c.bc -o x.bc
12 //===----------------------------------------------------------------------===//
57 // llvm-link to simulate ThinLTO backend processes.
61              "imported from bitcode in filename"),
65 // must be specified in the case were we request imports via the -import
67 // exported (imported by a different llvm-link -import invocation), to ensure
70     SummaryIndex("summary-index", cl::desc("Module summary index filename"),
75     OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
83     DisableDITypeMap("disable-debug-info-type-map",
87 static cl::opt<bool> OnlyNeeded("only-needed",
94 static cl::opt<bool> DisableLazyLoad("disable-lazy-loading",
109 static cl::opt<bool> SuppressWarnings("suppress-warnings",
114     "preserve-bc-uselistorder",
115     cl::desc("Preserve use-list order when writing LLVM bitcode."),
119     "preserve-ll-uselistorder",
120     cl::desc("Preserve use-list order when writing LLVM assembly."),
123 static cl::opt<bool> NoVerify("disable-verify",
128     "ignore-non-bitcode",
129     cl::desc("Do not report an error for non-bitcode files in archives"),
133     "try-experimental-debuginfo-iterators",
134     cl::desc("Enable debuginfo iterator positions, if they're built in"),
146 // Read the specified bitcode file in and return it. This routine searches the
155     errs() << "Loading '" << Buffer->getBufferIdentifier() << "'\n";  in loadFile()
169     ExitOnErr(Result->materializeMetadata());  in loadFile()
180   StringRef ArchiveName = Buffer->getBufferIdentifier();  in loadArFile()
185       object::Archive::create(Buffer->getMemBufferRef());  in loadArFile()
193   for (const object::Archive::Child &C : Archive->children(Err)) {  in loadArFile()
264   /// Create the loader, Module will be initialized in \p Context.
276     std::unique_ptr<Module> Ret = std::move(I->second);  in takeModule()
320 /// Import any functions requested via the -import option.
327   // Map of Module -> List of globals to import from the Module  in importFunctions()
364       errs() << "Ignoring import request for non-existent function "  in importFunctions()
371     if (F->hasWeakAnyLinkage()) {  in importFunctions()
372       errs() << "Ignoring import request for weak-any function " << FunctionName  in importFunctions()
380     // `-import` specifies the `<filename,function-name>` pairs to import as  in importFunctions()
382     // FIXME: A follow-up patch should add test coverage for import declaration  in importFunctions()
383     // in `llvm-link` CLI (e.g., by introducing a new command line option).  in importFunctions()
385         ImportList[FileNameStringCache.insert(FileName).first->getKey()];  in importFunctions()
386     Entry[F->getGUID()] = GlobalValueSummary::Definition;  in importFunctions()
417         identify_magic(Buffer->getBuffer()) == file_magic::archive  in linkFiles()
426     // Note that when ODR merging types cannot verify input files in here When  in linkFiles()
427     // doing that debug metadata in the src module might already be pointing to  in linkFiles()
446           if (GlobalValue::isLocalLinkage(S->linkage()))  in linkFiles()
447             S->setLinkage(GlobalValue::ExternalLinkage);  in linkFiles()
458       errs() << "Linking in '" << File << "'\n";  in linkFiles()
496   // Since llvm-link collects multiple IR modules together, for simplicity's  in main()
508   auto Composite = std::make_unique<Module>("llvm-link", Context);  in main()  local
509   Linker L(*Composite);  in main()
519   // Next the -override ones.  in main()
524   // Import any functions requested via -import  in main()
525   if (!importFunctions(argv[0], *Composite))  in main()
529     errs() << "Here's the assembly:\n" << *Composite;  in main()
540   if (!NoVerify && verifyModule(*Composite, &errs())) {  in main()
549     Composite->setIsNewDbgInfoFormat(NewFormat);  in main()
551       Composite->removeDebugIntrinsicDeclarations();  in main()
555     Composite->print(Out.os(), nullptr, PreserveAssemblyUseListOrder);  in main()
558     WriteBitcodeToFile(*Composite, Out.os(), PreserveBitcodeUseListOrder);  in main()