//===- llvm-link.cpp - Low-level LLVM linker ------------------------------===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// 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:
//
//===----------------------------------------------------------------------===//
-#include "llvm/Linker.h"
-#include "llvm/Module.h"
-#include "llvm/Analysis/Verifier.h"
-#include "llvm/Bytecode/Reader.h"
-#include "llvm/Bytecode/Writer.h"
+#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/System/Signals.h"
-#include "llvm/System/Path.h"
-#include <fstream>
-#include <iostream>
+#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 bytecode files>"));
+ 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> Force("f", cl::desc("Overwrite output files"));
+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> NoCompress("disable-compression", cl::init(false),
- cl::desc("Don't compress the generated bytecode"));
+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);
-// LoadFile - Read the specified bytecode file in and return it. This routine
-// searches the link path for the specified file to try to find it...
+// 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 inline std::auto_ptr<Module> LoadFile(const std::string &FN) {
- sys::Path Filename;
- if (!Filename.setFile(FN)) {
- std::cerr << "Invalid file name: '" << FN << "'\n";
- return std::auto_ptr<Module>();
+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);
}
- std::string ErrorMessage;
- if (Filename.exists()) {
- if (Verbose) std::cerr << "Loading '" << Filename.c_str() << "'\n";
- Module* Result = ParseBytecodeFile(Filename.toString(), &ErrorMessage);
- if (Result) return std::auto_ptr<Module>(Result); // Load successful!
+ return Result;
+}
- if (Verbose) {
- std::cerr << "Error opening bytecode file: '" << Filename.c_str() << "'";
- if (ErrorMessage.size()) std::cerr << ": " << ErrorMessage;
- std::cerr << "\n";
- }
- } else {
- std::cerr << "Bytecode file: '" << Filename.c_str()
- << "' does not exist.\n";
+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");
}
- return std::auto_ptr<Module>();
+ DiagnosticPrinterRawOStream DP(errs());
+ DI.print(DP);
+ errs() << '\n';
}
-int main(int argc, char **argv) {
- try {
- cl::ParseCommandLineOptions(argc, argv, " llvm linker\n");
- sys::PrintStackTraceOnErrorSignal();
- assert(InputFilenames.size() > 0 && "OneOrMore is not working");
-
- unsigned BaseArg = 0;
- std::string ErrorMessage;
-
- std::auto_ptr<Module> Composite(LoadFile(InputFilenames[BaseArg]));
- if (Composite.get() == 0) {
- std::cerr << argv[0] << ": error loading file '"
- << InputFilenames[BaseArg] << "'\n";
- return 1;
+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);
- for (unsigned i = BaseArg+1; i < InputFilenames.size(); ++i) {
- std::auto_ptr<Module> M(LoadFile(InputFilenames[i]));
- if (M.get() == 0) {
- std::cerr << argv[0] << ": error loading file '"
- << InputFilenames[i] << "'\n";
- return 1;
- }
+ // 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;
+ }
- if (Verbose) std::cerr << "Linking in '" << InputFilenames[i] << "'\n";
+ 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 (Linker::LinkModules(Composite.get(), M.get(), &ErrorMessage)) {
- std::cerr << argv[0] << ": link error in '" << InputFilenames[i]
- << "': " << ErrorMessage << "\n";
- return 1;
+ 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());
}
- // TODO: Iterate over the -l list and link in any modules containing
- // global symbols that have not been resolved so far.
+ // 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 *>>();
- if (DumpAsm) std::cerr << "Here's the assembly:\n" << Composite.get();
+ // 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;
+ }
- // FIXME: cout is not binary!
- std::ostream *Out = &std::cout; // Default to printing to stdout...
- if (OutputFilename != "-") {
- if (!Force && std::ifstream(OutputFilename.c_str())) {
- // If force is not specified, make sure not to overwrite a file!
- std::cerr << argv[0] << ": error opening '" << OutputFilename
- << "': file exists!\n"
- << "Use -f command line argument to force output\n";
- return 1;
- }
- std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
- std::ios::binary;
- Out = new std::ofstream(OutputFilename.c_str(), io_mode);
- if (!Out->good()) {
- std::cerr << argv[0] << ": error opening '" << OutputFilename << "'!\n";
- return 1;
- }
+ // 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;
+}
- // Make sure that the Out file gets unlinked from the disk if we get a
- // SIGINT
- sys::RemoveFileOnSignal(sys::Path(OutputFilename));
+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(*Composite.get())) {
- std::cerr << argv[0] << ": linked module is broken!\n";
- return 1;
+ if (verifyModule(*M, &errs())) {
+ errs() << argv0 << ": " << File << ": error: input module is broken!\n";
+ return false;
}
- if (Verbose) std::cerr << "Writing bytecode...\n";
- WriteBytecodeToFile(Composite.get(), *Out, !NoCompress);
+ // 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 (Out != &std::cout) delete Out;
- return 0;
- } catch (const std::string& msg) {
- std::cerr << argv[0] << ": " << msg << "\n";
- } catch (...) {
- std::cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
+ // 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 1;
+
+ 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;
}