llvm-link.cpp | Explore in Territory

//===- llvm-link.cpp - Low-level LLVM linker ------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This utility may be invoked in the following manner:
//  llvm-link a.bc b.bc c.bc -o x.bc
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/STLExtras.h"
#include "llvm/BinaryFormat/Magic.h"
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/Bitcode/BitcodeWriter.h"
#include "llvm/IR/AutoUpgrade.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/DiagnosticPrinter.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/IR/Verifier.h"
#include "llvm/IRReader/IRReader.h"
#include "llvm/Linker/Linker.h"
#include "llvm/Object/Archive.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Transforms/IPO/FunctionImport.h"
#include "llvm/Transforms/IPO/Internalize.h"
#include "llvm/Transforms/Utils/FunctionImportUtils.h"

#include <memory>
#include <utility>
usingnamespacellvm;

static cl::OptionCategory LinkCategory("Link Options");

static cl::list<std::string> InputFilenames(cl::Positional, cl::OneOrMore,
                                            cl::desc("<input bitcode files>"),
                                            cl::cat(LinkCategory));

static cl::list<std::string> OverridingInputs(
    "override", cl::value_desc("filename"),
    cl::desc(
        "input bitcode file which can override previously defined symbol(s)"),
    cl::cat(LinkCategory));

// 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::value_desc("function:filename"),
    cl::desc("Pair of function name and filename, where function should be "
             "imported from bitcode in filename"),
    cl::cat(LinkCategory));

// Option to support testing of function importing. The module summary
// 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>
    SummaryIndex("summary-index", cl::desc("Module summary index filename"),
                 cl::init(""), cl::value_desc("filename"),
                 cl::cat(LinkCategory));

static cl::opt<std::string>
    OutputFilename("o", cl::desc("Override output filename"), cl::init("-"),
                   cl::value_desc("filename"), cl::cat(LinkCategory));

static cl::opt<bool> Internalize("internalize",
                                 cl::desc("Internalize linked symbols"),
                                 cl::cat(LinkCategory));

static cl::opt<bool>
    DisableDITypeMap("disable-debug-info-type-map",
                     cl::desc("Don't use a uniquing type map for debug info"),
                     cl::cat(LinkCategory));

static cl::opt<bool> OnlyNeeded("only-needed",
                                cl::desc("Link only needed symbols"),
                                cl::cat(LinkCategory));

static cl::opt<bool> Force("f", cl::desc("Enable binary output on terminals"),
                           cl::cat(LinkCategory));

static cl::opt<bool> DisableLazyLoad("disable-lazy-loading",
                                     cl::desc("Disable lazy module loading"),
                                     cl::cat(LinkCategory));

static cl::opt<bool> OutputAssembly("S",
                                    cl::desc("Write output as LLVM assembly"),
                                    cl::Hidden, cl::cat(LinkCategory));

static cl::opt<bool> Verbose("v",
                             cl::desc("Print information about actions taken"),
                             cl::cat(LinkCategory));

static cl::opt<bool> DumpAsm("d", cl::desc("Print assembly as linked"),
                             cl::Hidden, cl::cat(LinkCategory));

static cl::opt<bool> SuppressWarnings("suppress-warnings",
                                      cl::desc("Suppress all linking warnings"),
                                      cl::init(false), cl::cat(LinkCategory));

static cl::opt<bool> PreserveBitcodeUseListOrder(
    "preserve-bc-uselistorder",
    cl::desc("Preserve use-list order when writing LLVM bitcode."),
    cl::init(true), cl::Hidden, cl::cat(LinkCategory));

static cl::opt<bool> PreserveAssemblyUseListOrder(
    "preserve-ll-uselistorder",
    cl::desc("Preserve use-list order when writing LLVM assembly."),
    cl::init(false), cl::Hidden, cl::cat(LinkCategory));

static cl::opt<bool> NoVerify("disable-verify",
                              cl::desc("Do not run the verifier"), cl::Hidden,
                              cl::cat(LinkCategory));

static cl::opt<bool> IgnoreNonBitcode(
    "ignore-non-bitcode",
    cl::desc("Do not report an error for non-bitcode files in archives"),
    cl::Hidden);

static cl::opt<bool> TryUseNewDbgInfoFormat(
    "try-experimental-debuginfo-iterators",
    cl::desc("Enable debuginfo iterator positions, if they're built in"),
    cl::init(false));

extern cl::opt<bool> UseNewDbgInfoFormat;
extern cl::opt<cl::boolOrDefault> PreserveInputDbgFormat;
extern cl::opt<bool> WriteNewDbgInfoFormat;
extern bool WriteNewDbgInfoFormatToBitcode;

extern cl::opt<cl::boolOrDefault> LoadBitcodeIntoNewDbgInfoFormat;

static ExitOnError ExitOnErr;

// 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,
                                        std::unique_ptr<MemoryBuffer> Buffer,
                                        LLVMContext &Context,
                                        bool MaterializeMetadata = true) { … }

static std::unique_ptr<Module> loadArFile(const char *Argv0,
                                          std::unique_ptr<MemoryBuffer> Buffer,
                                          LLVMContext &Context) { … }

namespace {

/// Helper to load on demand a Module from file and cache it for subsequent
/// queries during function importing.
class ModuleLazyLoaderCache { … };

// Get a Module for \p FileName from the cache, or load it lazily.
Module &ModuleLazyLoaderCache::operator()(const char *argv0,
                                          const std::string &Identifier) { … }
} // anonymous namespace

namespace {
struct LLVMLinkDiagnosticHandler : public DiagnosticHandler { … };
} // namespace

/// Import any functions requested via the -import option.
static bool importFunctions(const char *argv0, Module &DestModule) { … }

static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
                      const cl::list<std::string> &Files, unsigned Flags) { … }

int main(int argc, char **argv) { … }
llvm/llvm/tools/llvm-link/llvm-link.cpp
