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Diffstat (limited to 'contrib/llvm/tools/llvm-link/llvm-link.cpp')
| -rw-r--r-- | contrib/llvm/tools/llvm-link/llvm-link.cpp | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/contrib/llvm/tools/llvm-link/llvm-link.cpp b/contrib/llvm/tools/llvm-link/llvm-link.cpp new file mode 100644 index 0000000..a3238302 --- /dev/null +++ b/contrib/llvm/tools/llvm-link/llvm-link.cpp @@ -0,0 +1,358 @@ +//===- llvm-link.cpp - Low-level LLVM linker ------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This utility may be invoked in the following manner: +// llvm-link a.bc b.bc c.bc -o x.bc +// +//===----------------------------------------------------------------------===// + +#include "llvm/Linker/Linker.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/Bitcode/ReaderWriter.h" +#include "llvm/IR/AutoUpgrade.h" +#include "llvm/IR/DiagnosticInfo.h" +#include "llvm/IR/DiagnosticPrinter.h" +#include "llvm/IR/FunctionInfo.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/Verifier.h" +#include "llvm/IRReader/IRReader.h" +#include "llvm/Object/FunctionIndexObjectFile.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/FileSystem.h" +#include "llvm/Support/ManagedStatic.h" +#include "llvm/Support/Path.h" +#include "llvm/Support/PrettyStackTrace.h" +#include "llvm/Support/Signals.h" +#include "llvm/Support/SourceMgr.h" +#include "llvm/Support/SystemUtils.h" +#include "llvm/Support/ToolOutputFile.h" +#include <memory> +using namespace llvm; + +static cl::list<std::string> +InputFilenames(cl::Positional, cl::OneOrMore, + cl::desc("<input bitcode files>")); + +static cl::list<std::string> OverridingInputs( + "override", cl::ZeroOrMore, cl::value_desc("filename"), + cl::desc( + "input bitcode file which can override previously defined symbol(s)")); + +// Option to simulate function importing for testing. This enables using +// llvm-link to simulate ThinLTO backend processes. +static cl::list<std::string> Imports( + "import", cl::ZeroOrMore, cl::value_desc("function:filename"), + cl::desc("Pair of function name and filename, where function should be " + "imported from bitcode in filename")); + +// Option to support testing of function importing. The function index +// must be specified in the case were we request imports via the -import +// option, as well as when compiling any module with functions that may be +// exported (imported by a different llvm-link -import invocation), to ensure +// consistent promotion and renaming of locals. +static cl::opt<std::string> FunctionIndex("functionindex", + cl::desc("Function index filename"), + cl::init(""), + cl::value_desc("filename")); + +static cl::opt<std::string> +OutputFilename("o", cl::desc("Override output filename"), cl::init("-"), + cl::value_desc("filename")); + +static cl::opt<bool> +Internalize("internalize", cl::desc("Internalize linked symbols")); + +static cl::opt<bool> +OnlyNeeded("only-needed", cl::desc("Link only needed symbols")); + +static cl::opt<bool> +Force("f", cl::desc("Enable binary output on terminals")); + +static cl::opt<bool> +OutputAssembly("S", + cl::desc("Write output as LLVM assembly"), cl::Hidden); + +static cl::opt<bool> +Verbose("v", cl::desc("Print information about actions taken")); + +static cl::opt<bool> +DumpAsm("d", cl::desc("Print assembly as linked"), cl::Hidden); + +static cl::opt<bool> +SuppressWarnings("suppress-warnings", cl::desc("Suppress all linking warnings"), + cl::init(false)); + +static cl::opt<bool> + PreserveModules("preserve-modules", + cl::desc("Preserve linked modules for testing")); + +static cl::opt<bool> PreserveBitcodeUseListOrder( + "preserve-bc-uselistorder", + cl::desc("Preserve use-list order when writing LLVM bitcode."), + cl::init(true), cl::Hidden); + +static cl::opt<bool> PreserveAssemblyUseListOrder( + "preserve-ll-uselistorder", + cl::desc("Preserve use-list order when writing LLVM assembly."), + cl::init(false), cl::Hidden); + +// Read the specified bitcode file in and return it. This routine searches the +// link path for the specified file to try to find it... +// +static std::unique_ptr<Module> loadFile(const char *argv0, + const std::string &FN, + LLVMContext &Context, + bool MaterializeMetadata = true) { + SMDiagnostic Err; + if (Verbose) errs() << "Loading '" << FN << "'\n"; + std::unique_ptr<Module> Result = + getLazyIRFileModule(FN, Err, Context, !MaterializeMetadata); + if (!Result) + Err.print(argv0, errs()); + + if (MaterializeMetadata) { + Result->materializeMetadata(); + UpgradeDebugInfo(*Result); + } + + return Result; +} + +static void diagnosticHandler(const DiagnosticInfo &DI) { + unsigned Severity = DI.getSeverity(); + switch (Severity) { + case DS_Error: + errs() << "ERROR: "; + break; + case DS_Warning: + if (SuppressWarnings) + return; + errs() << "WARNING: "; + break; + case DS_Remark: + case DS_Note: + llvm_unreachable("Only expecting warnings and errors"); + } + + DiagnosticPrinterRawOStream DP(errs()); + DI.print(DP); + errs() << '\n'; +} + +static void diagnosticHandlerWithContext(const DiagnosticInfo &DI, void *C) { + diagnosticHandler(DI); +} + +/// Import any functions requested via the -import option. +static bool importFunctions(const char *argv0, LLVMContext &Context, + Linker &L) { + StringMap<std::unique_ptr<DenseMap<unsigned, MDNode *>>> + ModuleToTempMDValsMap; + for (const auto &Import : Imports) { + // Identify the requested function and its bitcode source file. + size_t Idx = Import.find(':'); + if (Idx == std::string::npos) { + errs() << "Import parameter bad format: " << Import << "\n"; + return false; + } + std::string FunctionName = Import.substr(0, Idx); + std::string FileName = Import.substr(Idx + 1, std::string::npos); + + // Load the specified source module. + std::unique_ptr<Module> M = loadFile(argv0, FileName, Context, false); + if (!M.get()) { + errs() << argv0 << ": error loading file '" << FileName << "'\n"; + return false; + } + + if (verifyModule(*M, &errs())) { + errs() << argv0 << ": " << FileName + << ": error: input module is broken!\n"; + return false; + } + + Function *F = M->getFunction(FunctionName); + if (!F) { + errs() << "Ignoring import request for non-existent function " + << FunctionName << " from " << FileName << "\n"; + continue; + } + // We cannot import weak_any functions without possibly affecting the + // order they are seen and selected by the linker, changing program + // semantics. + if (F->hasWeakAnyLinkage()) { + errs() << "Ignoring import request for weak-any function " << FunctionName + << " from " << FileName << "\n"; + continue; + } + + if (Verbose) + errs() << "Importing " << FunctionName << " from " << FileName << "\n"; + + std::unique_ptr<FunctionInfoIndex> Index; + if (!FunctionIndex.empty()) { + ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr = + llvm::getFunctionIndexForFile(FunctionIndex, diagnosticHandler); + std::error_code EC = IndexOrErr.getError(); + if (EC) { + errs() << EC.message() << '\n'; + return false; + } + Index = std::move(IndexOrErr.get()); + } + + // Save the mapping of value ids to temporary metadata created when + // importing this function. If we have already imported from this module, + // add new temporary metadata to the existing mapping. + auto &TempMDVals = ModuleToTempMDValsMap[FileName]; + if (!TempMDVals) + TempMDVals = llvm::make_unique<DenseMap<unsigned, MDNode *>>(); + + // Link in the specified function. + DenseSet<const GlobalValue *> FunctionsToImport; + FunctionsToImport.insert(F); + if (L.linkInModule(std::move(M), Linker::Flags::None, Index.get(), + &FunctionsToImport, TempMDVals.get())) + return false; + } + + // Now link in metadata for all modules from which we imported functions. + for (StringMapEntry<std::unique_ptr<DenseMap<unsigned, MDNode *>>> &SME : + ModuleToTempMDValsMap) { + // Load the specified source module. + std::unique_ptr<Module> M = loadFile(argv0, SME.getKey(), Context, true); + if (!M.get()) { + errs() << argv0 << ": error loading file '" << SME.getKey() << "'\n"; + return false; + } + + if (verifyModule(*M, &errs())) { + errs() << argv0 << ": " << SME.getKey() + << ": error: input module is broken!\n"; + return false; + } + + // Link in all necessary metadata from this module. + if (L.linkInMetadata(*M, SME.getValue().get())) + return false; + } + return true; +} + +static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L, + const cl::list<std::string> &Files, + unsigned Flags) { + // Filter out flags that don't apply to the first file we load. + unsigned ApplicableFlags = Flags & Linker::Flags::OverrideFromSrc; + for (const auto &File : Files) { + std::unique_ptr<Module> M = loadFile(argv0, File, Context); + if (!M.get()) { + errs() << argv0 << ": error loading file '" << File << "'\n"; + return false; + } + + if (verifyModule(*M, &errs())) { + errs() << argv0 << ": " << File << ": error: input module is broken!\n"; + return false; + } + + // If a function index is supplied, load it so linkInModule can treat + // local functions/variables as exported and promote if necessary. + std::unique_ptr<FunctionInfoIndex> Index; + if (!FunctionIndex.empty()) { + ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr = + llvm::getFunctionIndexForFile(FunctionIndex, diagnosticHandler); + std::error_code EC = IndexOrErr.getError(); + if (EC) { + errs() << EC.message() << '\n'; + return false; + } + Index = std::move(IndexOrErr.get()); + } + + if (Verbose) + errs() << "Linking in '" << File << "'\n"; + + if (L.linkInModule(std::move(M), ApplicableFlags, Index.get())) + return false; + // All linker flags apply to linking of subsequent files. + ApplicableFlags = Flags; + + // If requested for testing, preserve modules by releasing them from + // the unique_ptr before the are freed. This can help catch any + // cross-module references from e.g. unneeded metadata references + // that aren't properly set to null but instead mapped to the source + // module version. The bitcode writer will assert if it finds any such + // cross-module references. + if (PreserveModules) + M.release(); + } + + return true; +} + +int main(int argc, char **argv) { + // Print a stack trace if we signal out. + sys::PrintStackTraceOnErrorSignal(); + PrettyStackTraceProgram X(argc, argv); + + LLVMContext &Context = getGlobalContext(); + Context.setDiagnosticHandler(diagnosticHandlerWithContext, nullptr, true); + + llvm_shutdown_obj Y; // Call llvm_shutdown() on exit. + cl::ParseCommandLineOptions(argc, argv, "llvm linker\n"); + + auto Composite = make_unique<Module>("llvm-link", Context); + Linker L(*Composite); + + unsigned Flags = Linker::Flags::None; + if (Internalize) + Flags |= Linker::Flags::InternalizeLinkedSymbols; + if (OnlyNeeded) + Flags |= Linker::Flags::LinkOnlyNeeded; + + // First add all the regular input files + if (!linkFiles(argv[0], Context, L, InputFilenames, Flags)) + return 1; + + // Next the -override ones. + if (!linkFiles(argv[0], Context, L, OverridingInputs, + Flags | Linker::Flags::OverrideFromSrc)) + return 1; + + // Import any functions requested via -import + if (!importFunctions(argv[0], Context, L)) + return 1; + + if (DumpAsm) errs() << "Here's the assembly:\n" << *Composite; + + std::error_code EC; + tool_output_file Out(OutputFilename, EC, sys::fs::F_None); + if (EC) { + errs() << EC.message() << '\n'; + return 1; + } + + if (verifyModule(*Composite, &errs())) { + errs() << argv[0] << ": error: linked module is broken!\n"; + return 1; + } + + if (Verbose) errs() << "Writing bitcode...\n"; + if (OutputAssembly) { + Composite->print(Out.os(), nullptr, PreserveAssemblyUseListOrder); + } else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true)) + WriteBitcodeToFile(Composite.get(), Out.os(), PreserveBitcodeUseListOrder); + + // Declare success. + Out.keep(); + + return 0; +} |
