forked from OSchip/llvm-project
978 lines
34 KiB
C++
978 lines
34 KiB
C++
//===-- gold-plugin.cpp - Plugin to gold for Link Time Optimization ------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This is a gold plugin for LLVM. It provides an LLVM implementation of the
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// interface described in http://gcc.gnu.org/wiki/whopr/driver .
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ADT/Statistic.h"
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#include "llvm/Bitcode/BitcodeReader.h"
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#include "llvm/Bitcode/BitcodeWriter.h"
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#include "llvm/CodeGen/CommandFlags.h"
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#include "llvm/Config/config.h" // plugin-api.h requires HAVE_STDINT_H
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DiagnosticPrinter.h"
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#include "llvm/LTO/Caching.h"
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#include "llvm/LTO/LTO.h"
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#include "llvm/Object/Error.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/ManagedStatic.h"
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#include "llvm/Support/MemoryBuffer.h"
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#include "llvm/Support/Path.h"
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#include "llvm/Support/TargetSelect.h"
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#include "llvm/Support/raw_ostream.h"
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#include <list>
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#include <map>
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#include <plugin-api.h>
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#include <string>
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#include <system_error>
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#include <utility>
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#include <vector>
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// FIXME: remove this declaration when we stop maintaining Ubuntu Quantal and
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// Precise and Debian Wheezy (binutils 2.23 is required)
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#define LDPO_PIE 3
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#define LDPT_GET_SYMBOLS_V3 28
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using namespace llvm;
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using namespace lto;
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static ld_plugin_status discard_message(int level, const char *format, ...) {
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// Die loudly. Recent versions of Gold pass ld_plugin_message as the first
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// callback in the transfer vector. This should never be called.
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abort();
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}
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static ld_plugin_release_input_file release_input_file = nullptr;
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static ld_plugin_get_input_file get_input_file = nullptr;
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static ld_plugin_message message = discard_message;
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namespace {
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struct claimed_file {
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void *handle;
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void *leader_handle;
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std::vector<ld_plugin_symbol> syms;
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off_t filesize;
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std::string name;
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};
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/// RAII wrapper to manage opening and releasing of a ld_plugin_input_file.
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struct PluginInputFile {
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void *Handle;
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std::unique_ptr<ld_plugin_input_file> File;
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PluginInputFile(void *Handle) : Handle(Handle) {
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File = llvm::make_unique<ld_plugin_input_file>();
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if (get_input_file(Handle, File.get()) != LDPS_OK)
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message(LDPL_FATAL, "Failed to get file information");
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}
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~PluginInputFile() {
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// File would have been reset to nullptr if we moved this object
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// to a new owner.
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if (File)
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if (release_input_file(Handle) != LDPS_OK)
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message(LDPL_FATAL, "Failed to release file information");
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}
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ld_plugin_input_file &file() { return *File; }
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PluginInputFile(PluginInputFile &&RHS) = default;
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PluginInputFile &operator=(PluginInputFile &&RHS) = default;
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};
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struct ResolutionInfo {
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bool CanOmitFromDynSym = true;
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bool DefaultVisibility = true;
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};
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}
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static ld_plugin_add_symbols add_symbols = nullptr;
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static ld_plugin_get_symbols get_symbols = nullptr;
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static ld_plugin_add_input_file add_input_file = nullptr;
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static ld_plugin_set_extra_library_path set_extra_library_path = nullptr;
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static ld_plugin_get_view get_view = nullptr;
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static bool IsExecutable = false;
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static Optional<Reloc::Model> RelocationModel = None;
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static std::string output_name = "";
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static std::list<claimed_file> Modules;
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static DenseMap<int, void *> FDToLeaderHandle;
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static StringMap<ResolutionInfo> ResInfo;
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static std::vector<std::string> Cleanup;
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namespace options {
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enum OutputType {
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OT_NORMAL,
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OT_DISABLE,
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OT_BC_ONLY,
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OT_SAVE_TEMPS
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};
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static OutputType TheOutputType = OT_NORMAL;
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static unsigned OptLevel = 2;
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// Default parallelism of 0 used to indicate that user did not specify.
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// Actual parallelism default value depends on implementation.
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// Currently only affects ThinLTO, where the default is
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// llvm::heavyweight_hardware_concurrency.
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static unsigned Parallelism = 0;
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// Default regular LTO codegen parallelism (number of partitions).
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static unsigned ParallelCodeGenParallelismLevel = 1;
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#ifdef NDEBUG
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static bool DisableVerify = true;
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#else
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static bool DisableVerify = false;
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#endif
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static std::string obj_path;
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static std::string extra_library_path;
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static std::string triple;
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static std::string mcpu;
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// When the thinlto plugin option is specified, only read the function
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// the information from intermediate files and write a combined
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// global index for the ThinLTO backends.
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static bool thinlto = false;
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// If false, all ThinLTO backend compilations through code gen are performed
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// using multiple threads in the gold-plugin, before handing control back to
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// gold. If true, write individual backend index files which reflect
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// the import decisions, and exit afterwards. The assumption is
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// that the build system will launch the backend processes.
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static bool thinlto_index_only = false;
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// If non-empty, holds the name of a file in which to write the list of
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// oject files gold selected for inclusion in the link after symbol
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// resolution (i.e. they had selected symbols). This will only be non-empty
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// in the thinlto_index_only case. It is used to identify files, which may
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// have originally been within archive libraries specified via
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// --start-lib/--end-lib pairs, that should be included in the final
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// native link process (since intervening function importing and inlining
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// may change the symbol resolution detected in the final link and which
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// files to include out of --start-lib/--end-lib libraries as a result).
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static std::string thinlto_linked_objects_file;
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// If true, when generating individual index files for distributed backends,
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// also generate a "${bitcodefile}.imports" file at the same location for each
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// bitcode file, listing the files it imports from in plain text. This is to
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// support distributed build file staging.
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static bool thinlto_emit_imports_files = false;
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// Option to control where files for a distributed backend (the individual
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// index files and optional imports files) are created.
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// If specified, expects a string of the form "oldprefix:newprefix", and
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// instead of generating these files in the same directory path as the
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// corresponding bitcode file, will use a path formed by replacing the
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// bitcode file's path prefix matching oldprefix with newprefix.
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static std::string thinlto_prefix_replace;
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// Option to control the name of modules encoded in the individual index
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// files for a distributed backend. This enables the use of minimized
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// bitcode files for the thin link, assuming the name of the full bitcode
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// file used in the backend differs just in some part of the file suffix.
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// If specified, expects a string of the form "oldsuffix:newsuffix".
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static std::string thinlto_object_suffix_replace;
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// Optional path to a directory for caching ThinLTO objects.
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static std::string cache_dir;
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// Additional options to pass into the code generator.
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// Note: This array will contain all plugin options which are not claimed
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// as plugin exclusive to pass to the code generator.
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static std::vector<const char *> extra;
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// Sample profile file path
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static std::string sample_profile;
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static void process_plugin_option(const char *opt_)
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{
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if (opt_ == nullptr)
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return;
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llvm::StringRef opt = opt_;
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if (opt.startswith("mcpu=")) {
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mcpu = opt.substr(strlen("mcpu="));
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} else if (opt.startswith("extra-library-path=")) {
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extra_library_path = opt.substr(strlen("extra_library_path="));
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} else if (opt.startswith("mtriple=")) {
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triple = opt.substr(strlen("mtriple="));
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} else if (opt.startswith("obj-path=")) {
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obj_path = opt.substr(strlen("obj-path="));
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} else if (opt == "emit-llvm") {
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TheOutputType = OT_BC_ONLY;
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} else if (opt == "save-temps") {
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TheOutputType = OT_SAVE_TEMPS;
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} else if (opt == "disable-output") {
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TheOutputType = OT_DISABLE;
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} else if (opt == "thinlto") {
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thinlto = true;
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} else if (opt == "thinlto-index-only") {
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thinlto_index_only = true;
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} else if (opt.startswith("thinlto-index-only=")) {
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thinlto_index_only = true;
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thinlto_linked_objects_file = opt.substr(strlen("thinlto-index-only="));
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} else if (opt == "thinlto-emit-imports-files") {
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thinlto_emit_imports_files = true;
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} else if (opt.startswith("thinlto-prefix-replace=")) {
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thinlto_prefix_replace = opt.substr(strlen("thinlto-prefix-replace="));
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if (thinlto_prefix_replace.find(';') == std::string::npos)
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message(LDPL_FATAL, "thinlto-prefix-replace expects 'old;new' format");
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} else if (opt.startswith("thinlto-object-suffix-replace=")) {
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thinlto_object_suffix_replace =
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opt.substr(strlen("thinlto-object-suffix-replace="));
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if (thinlto_object_suffix_replace.find(';') == std::string::npos)
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message(LDPL_FATAL,
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"thinlto-object-suffix-replace expects 'old;new' format");
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} else if (opt.startswith("cache-dir=")) {
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cache_dir = opt.substr(strlen("cache-dir="));
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} else if (opt.size() == 2 && opt[0] == 'O') {
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if (opt[1] < '0' || opt[1] > '3')
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message(LDPL_FATAL, "Optimization level must be between 0 and 3");
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OptLevel = opt[1] - '0';
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} else if (opt.startswith("jobs=")) {
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if (StringRef(opt_ + 5).getAsInteger(10, Parallelism))
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message(LDPL_FATAL, "Invalid parallelism level: %s", opt_ + 5);
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} else if (opt.startswith("lto-partitions=")) {
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if (opt.substr(strlen("lto-partitions="))
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.getAsInteger(10, ParallelCodeGenParallelismLevel))
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message(LDPL_FATAL, "Invalid codegen partition level: %s", opt_ + 5);
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} else if (opt == "disable-verify") {
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DisableVerify = true;
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} else if (opt.startswith("sample-profile=")) {
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sample_profile= opt.substr(strlen("sample-profile="));
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} else {
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// Save this option to pass to the code generator.
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// ParseCommandLineOptions() expects argv[0] to be program name. Lazily
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// add that.
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if (extra.empty())
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extra.push_back("LLVMgold");
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extra.push_back(opt_);
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}
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}
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}
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static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
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int *claimed);
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static ld_plugin_status all_symbols_read_hook(void);
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static ld_plugin_status cleanup_hook(void);
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extern "C" ld_plugin_status onload(ld_plugin_tv *tv);
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ld_plugin_status onload(ld_plugin_tv *tv) {
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InitializeAllTargetInfos();
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InitializeAllTargets();
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InitializeAllTargetMCs();
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InitializeAllAsmParsers();
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InitializeAllAsmPrinters();
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// We're given a pointer to the first transfer vector. We read through them
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// until we find one where tv_tag == LDPT_NULL. The REGISTER_* tagged values
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// contain pointers to functions that we need to call to register our own
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// hooks. The others are addresses of functions we can use to call into gold
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// for services.
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bool registeredClaimFile = false;
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bool RegisteredAllSymbolsRead = false;
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for (; tv->tv_tag != LDPT_NULL; ++tv) {
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// Cast tv_tag to int to allow values not in "enum ld_plugin_tag", like, for
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// example, LDPT_GET_SYMBOLS_V3 when building against an older plugin-api.h
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// header.
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switch (static_cast<int>(tv->tv_tag)) {
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case LDPT_OUTPUT_NAME:
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output_name = tv->tv_u.tv_string;
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break;
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case LDPT_LINKER_OUTPUT:
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switch (tv->tv_u.tv_val) {
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case LDPO_REL: // .o
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IsExecutable = false;
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break;
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case LDPO_DYN: // .so
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IsExecutable = false;
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RelocationModel = Reloc::PIC_;
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break;
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case LDPO_PIE: // position independent executable
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IsExecutable = true;
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RelocationModel = Reloc::PIC_;
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break;
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case LDPO_EXEC: // .exe
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IsExecutable = true;
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RelocationModel = Reloc::Static;
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break;
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default:
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message(LDPL_ERROR, "Unknown output file type %d", tv->tv_u.tv_val);
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return LDPS_ERR;
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}
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break;
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case LDPT_OPTION:
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options::process_plugin_option(tv->tv_u.tv_string);
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break;
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case LDPT_REGISTER_CLAIM_FILE_HOOK: {
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ld_plugin_register_claim_file callback;
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callback = tv->tv_u.tv_register_claim_file;
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if (callback(claim_file_hook) != LDPS_OK)
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return LDPS_ERR;
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registeredClaimFile = true;
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} break;
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case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: {
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ld_plugin_register_all_symbols_read callback;
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callback = tv->tv_u.tv_register_all_symbols_read;
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if (callback(all_symbols_read_hook) != LDPS_OK)
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return LDPS_ERR;
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RegisteredAllSymbolsRead = true;
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} break;
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case LDPT_REGISTER_CLEANUP_HOOK: {
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ld_plugin_register_cleanup callback;
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callback = tv->tv_u.tv_register_cleanup;
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if (callback(cleanup_hook) != LDPS_OK)
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return LDPS_ERR;
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} break;
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case LDPT_GET_INPUT_FILE:
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get_input_file = tv->tv_u.tv_get_input_file;
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break;
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case LDPT_RELEASE_INPUT_FILE:
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release_input_file = tv->tv_u.tv_release_input_file;
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break;
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case LDPT_ADD_SYMBOLS:
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add_symbols = tv->tv_u.tv_add_symbols;
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break;
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case LDPT_GET_SYMBOLS_V2:
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// Do not override get_symbols_v3 with get_symbols_v2.
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if (!get_symbols)
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get_symbols = tv->tv_u.tv_get_symbols;
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break;
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case LDPT_GET_SYMBOLS_V3:
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get_symbols = tv->tv_u.tv_get_symbols;
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break;
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case LDPT_ADD_INPUT_FILE:
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add_input_file = tv->tv_u.tv_add_input_file;
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break;
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case LDPT_SET_EXTRA_LIBRARY_PATH:
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set_extra_library_path = tv->tv_u.tv_set_extra_library_path;
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break;
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case LDPT_GET_VIEW:
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get_view = tv->tv_u.tv_get_view;
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break;
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case LDPT_MESSAGE:
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message = tv->tv_u.tv_message;
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break;
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default:
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break;
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}
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}
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if (!registeredClaimFile) {
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message(LDPL_ERROR, "register_claim_file not passed to LLVMgold.");
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return LDPS_ERR;
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}
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if (!add_symbols) {
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message(LDPL_ERROR, "add_symbols not passed to LLVMgold.");
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return LDPS_ERR;
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}
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if (!RegisteredAllSymbolsRead)
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return LDPS_OK;
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if (!get_input_file) {
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message(LDPL_ERROR, "get_input_file not passed to LLVMgold.");
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return LDPS_ERR;
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}
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if (!release_input_file) {
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message(LDPL_ERROR, "release_input_file not passed to LLVMgold.");
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return LDPS_ERR;
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}
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return LDPS_OK;
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}
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static void diagnosticHandler(const DiagnosticInfo &DI) {
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std::string ErrStorage;
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{
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raw_string_ostream OS(ErrStorage);
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DiagnosticPrinterRawOStream DP(OS);
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DI.print(DP);
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}
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ld_plugin_level Level;
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switch (DI.getSeverity()) {
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case DS_Error:
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message(LDPL_FATAL, "LLVM gold plugin has failed to create LTO module: %s",
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ErrStorage.c_str());
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case DS_Warning:
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Level = LDPL_WARNING;
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break;
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case DS_Note:
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case DS_Remark:
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Level = LDPL_INFO;
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break;
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}
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message(Level, "LLVM gold plugin: %s", ErrStorage.c_str());
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}
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static void check(Error E, std::string Msg = "LLVM gold plugin") {
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handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) -> Error {
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message(LDPL_FATAL, "%s: %s", Msg.c_str(), EIB.message().c_str());
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return Error::success();
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});
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}
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template <typename T> static T check(Expected<T> E) {
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if (E)
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return std::move(*E);
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check(E.takeError());
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return T();
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}
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/// Called by gold to see whether this file is one that our plugin can handle.
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/// We'll try to open it and register all the symbols with add_symbol if
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/// possible.
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static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
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int *claimed) {
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MemoryBufferRef BufferRef;
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std::unique_ptr<MemoryBuffer> Buffer;
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if (get_view) {
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const void *view;
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if (get_view(file->handle, &view) != LDPS_OK) {
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message(LDPL_ERROR, "Failed to get a view of %s", file->name);
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return LDPS_ERR;
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}
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BufferRef =
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MemoryBufferRef(StringRef((const char *)view, file->filesize), "");
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} else {
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int64_t offset = 0;
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// Gold has found what might be IR part-way inside of a file, such as
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// an .a archive.
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if (file->offset) {
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offset = file->offset;
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}
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ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
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MemoryBuffer::getOpenFileSlice(file->fd, file->name, file->filesize,
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offset);
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if (std::error_code EC = BufferOrErr.getError()) {
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message(LDPL_ERROR, EC.message().c_str());
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return LDPS_ERR;
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}
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Buffer = std::move(BufferOrErr.get());
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BufferRef = Buffer->getMemBufferRef();
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}
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*claimed = 1;
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Expected<std::unique_ptr<InputFile>> ObjOrErr = InputFile::create(BufferRef);
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|
if (!ObjOrErr) {
|
|
handleAllErrors(ObjOrErr.takeError(), [&](const ErrorInfoBase &EI) {
|
|
std::error_code EC = EI.convertToErrorCode();
|
|
if (EC == object::object_error::invalid_file_type ||
|
|
EC == object::object_error::bitcode_section_not_found)
|
|
*claimed = 0;
|
|
else
|
|
message(LDPL_FATAL,
|
|
"LLVM gold plugin has failed to create LTO module: %s",
|
|
EI.message().c_str());
|
|
});
|
|
|
|
return *claimed ? LDPS_ERR : LDPS_OK;
|
|
}
|
|
|
|
std::unique_ptr<InputFile> Obj = std::move(*ObjOrErr);
|
|
|
|
Modules.emplace_back();
|
|
claimed_file &cf = Modules.back();
|
|
|
|
cf.handle = file->handle;
|
|
// Keep track of the first handle for each file descriptor, since there are
|
|
// multiple in the case of an archive. This is used later in the case of
|
|
// ThinLTO parallel backends to ensure that each file is only opened and
|
|
// released once.
|
|
auto LeaderHandle =
|
|
FDToLeaderHandle.insert(std::make_pair(file->fd, file->handle)).first;
|
|
cf.leader_handle = LeaderHandle->second;
|
|
// Save the filesize since for parallel ThinLTO backends we can only
|
|
// invoke get_input_file once per archive (only for the leader handle).
|
|
cf.filesize = file->filesize;
|
|
// In the case of an archive library, all but the first member must have a
|
|
// non-zero offset, which we can append to the file name to obtain a
|
|
// unique name.
|
|
cf.name = file->name;
|
|
if (file->offset)
|
|
cf.name += ".llvm." + std::to_string(file->offset) + "." +
|
|
sys::path::filename(Obj->getSourceFileName()).str();
|
|
|
|
for (auto &Sym : Obj->symbols()) {
|
|
cf.syms.push_back(ld_plugin_symbol());
|
|
ld_plugin_symbol &sym = cf.syms.back();
|
|
sym.version = nullptr;
|
|
StringRef Name = Sym.getName();
|
|
sym.name = strdup(Name.str().c_str());
|
|
|
|
ResolutionInfo &Res = ResInfo[Name];
|
|
|
|
Res.CanOmitFromDynSym &= Sym.canBeOmittedFromSymbolTable();
|
|
|
|
sym.visibility = LDPV_DEFAULT;
|
|
GlobalValue::VisibilityTypes Vis = Sym.getVisibility();
|
|
if (Vis != GlobalValue::DefaultVisibility)
|
|
Res.DefaultVisibility = false;
|
|
switch (Vis) {
|
|
case GlobalValue::DefaultVisibility:
|
|
break;
|
|
case GlobalValue::HiddenVisibility:
|
|
sym.visibility = LDPV_HIDDEN;
|
|
break;
|
|
case GlobalValue::ProtectedVisibility:
|
|
sym.visibility = LDPV_PROTECTED;
|
|
break;
|
|
}
|
|
|
|
if (Sym.isUndefined()) {
|
|
sym.def = LDPK_UNDEF;
|
|
if (Sym.isWeak())
|
|
sym.def = LDPK_WEAKUNDEF;
|
|
} else if (Sym.isCommon())
|
|
sym.def = LDPK_COMMON;
|
|
else if (Sym.isWeak())
|
|
sym.def = LDPK_WEAKDEF;
|
|
else
|
|
sym.def = LDPK_DEF;
|
|
|
|
sym.size = 0;
|
|
sym.comdat_key = nullptr;
|
|
int CI = Sym.getComdatIndex();
|
|
if (CI != -1) {
|
|
StringRef C = Obj->getComdatTable()[CI];
|
|
sym.comdat_key = strdup(C.str().c_str());
|
|
}
|
|
|
|
sym.resolution = LDPR_UNKNOWN;
|
|
}
|
|
|
|
if (!cf.syms.empty()) {
|
|
if (add_symbols(cf.handle, cf.syms.size(), cf.syms.data()) != LDPS_OK) {
|
|
message(LDPL_ERROR, "Unable to add symbols!");
|
|
return LDPS_ERR;
|
|
}
|
|
}
|
|
|
|
return LDPS_OK;
|
|
}
|
|
|
|
static void freeSymName(ld_plugin_symbol &Sym) {
|
|
free(Sym.name);
|
|
free(Sym.comdat_key);
|
|
Sym.name = nullptr;
|
|
Sym.comdat_key = nullptr;
|
|
}
|
|
|
|
/// Helper to get a file's symbols and a view into it via gold callbacks.
|
|
static const void *getSymbolsAndView(claimed_file &F) {
|
|
ld_plugin_status status = get_symbols(F.handle, F.syms.size(), F.syms.data());
|
|
if (status == LDPS_NO_SYMS)
|
|
return nullptr;
|
|
|
|
if (status != LDPS_OK)
|
|
message(LDPL_FATAL, "Failed to get symbol information");
|
|
|
|
const void *View;
|
|
if (get_view(F.handle, &View) != LDPS_OK)
|
|
message(LDPL_FATAL, "Failed to get a view of file");
|
|
|
|
return View;
|
|
}
|
|
|
|
/// Parse the thinlto-object-suffix-replace option into the \p OldSuffix and
|
|
/// \p NewSuffix strings, if it was specified.
|
|
static void getThinLTOOldAndNewSuffix(std::string &OldSuffix,
|
|
std::string &NewSuffix) {
|
|
assert(options::thinlto_object_suffix_replace.empty() ||
|
|
options::thinlto_object_suffix_replace.find(";") != StringRef::npos);
|
|
StringRef SuffixReplace = options::thinlto_object_suffix_replace;
|
|
std::pair<StringRef, StringRef> Split = SuffixReplace.split(";");
|
|
OldSuffix = Split.first.str();
|
|
NewSuffix = Split.second.str();
|
|
}
|
|
|
|
/// Given the original \p Path to an output file, replace any filename
|
|
/// suffix matching \p OldSuffix with \p NewSuffix.
|
|
static std::string getThinLTOObjectFileName(const std::string Path,
|
|
const std::string &OldSuffix,
|
|
const std::string &NewSuffix) {
|
|
if (OldSuffix.empty() && NewSuffix.empty())
|
|
return Path;
|
|
StringRef NewPath = Path;
|
|
NewPath.consume_back(OldSuffix);
|
|
std::string NewNewPath = NewPath.str() + NewSuffix;
|
|
return NewPath.str() + NewSuffix;
|
|
}
|
|
|
|
static bool isAlpha(char C) {
|
|
return ('a' <= C && C <= 'z') || ('A' <= C && C <= 'Z') || C == '_';
|
|
}
|
|
|
|
static bool isAlnum(char C) { return isAlpha(C) || ('0' <= C && C <= '9'); }
|
|
|
|
// Returns true if S is valid as a C language identifier.
|
|
static bool isValidCIdentifier(StringRef S) {
|
|
return !S.empty() && isAlpha(S[0]) &&
|
|
std::all_of(S.begin() + 1, S.end(), isAlnum);
|
|
}
|
|
|
|
static void addModule(LTO &Lto, claimed_file &F, const void *View,
|
|
StringRef Filename) {
|
|
MemoryBufferRef BufferRef(StringRef((const char *)View, F.filesize),
|
|
Filename);
|
|
Expected<std::unique_ptr<InputFile>> ObjOrErr = InputFile::create(BufferRef);
|
|
|
|
if (!ObjOrErr)
|
|
message(LDPL_FATAL, "Could not read bitcode from file : %s",
|
|
toString(ObjOrErr.takeError()).c_str());
|
|
|
|
unsigned SymNum = 0;
|
|
std::unique_ptr<InputFile> Input = std::move(ObjOrErr.get());
|
|
auto InputFileSyms = Input->symbols();
|
|
assert(InputFileSyms.size() == F.syms.size());
|
|
std::vector<SymbolResolution> Resols(F.syms.size());
|
|
for (ld_plugin_symbol &Sym : F.syms) {
|
|
const InputFile::Symbol &InpSym = InputFileSyms[SymNum];
|
|
SymbolResolution &R = Resols[SymNum++];
|
|
|
|
ld_plugin_symbol_resolution Resolution =
|
|
(ld_plugin_symbol_resolution)Sym.resolution;
|
|
|
|
ResolutionInfo &Res = ResInfo[Sym.name];
|
|
|
|
switch (Resolution) {
|
|
case LDPR_UNKNOWN:
|
|
llvm_unreachable("Unexpected resolution");
|
|
|
|
case LDPR_RESOLVED_IR:
|
|
case LDPR_RESOLVED_EXEC:
|
|
case LDPR_RESOLVED_DYN:
|
|
case LDPR_PREEMPTED_IR:
|
|
case LDPR_PREEMPTED_REG:
|
|
case LDPR_UNDEF:
|
|
break;
|
|
|
|
case LDPR_PREVAILING_DEF_IRONLY:
|
|
R.Prevailing = true;
|
|
break;
|
|
|
|
case LDPR_PREVAILING_DEF:
|
|
R.Prevailing = true;
|
|
R.VisibleToRegularObj = true;
|
|
break;
|
|
|
|
case LDPR_PREVAILING_DEF_IRONLY_EXP:
|
|
R.Prevailing = true;
|
|
if (!Res.CanOmitFromDynSym)
|
|
R.VisibleToRegularObj = true;
|
|
break;
|
|
}
|
|
|
|
// If the symbol has a C identifier section name, we need to mark
|
|
// it as visible to a regular object so that LTO will keep it around
|
|
// to ensure the linker generates special __start_<secname> and
|
|
// __stop_<secname> symbols which may be used elsewhere.
|
|
if (isValidCIdentifier(InpSym.getSectionName()))
|
|
R.VisibleToRegularObj = true;
|
|
|
|
if (Resolution != LDPR_RESOLVED_DYN && Resolution != LDPR_UNDEF &&
|
|
(IsExecutable || !Res.DefaultVisibility))
|
|
R.FinalDefinitionInLinkageUnit = true;
|
|
|
|
freeSymName(Sym);
|
|
}
|
|
|
|
check(Lto.add(std::move(Input), Resols),
|
|
std::string("Failed to link module ") + F.name);
|
|
}
|
|
|
|
static void recordFile(std::string Filename, bool TempOutFile) {
|
|
if (add_input_file(Filename.c_str()) != LDPS_OK)
|
|
message(LDPL_FATAL,
|
|
"Unable to add .o file to the link. File left behind in: %s",
|
|
Filename.c_str());
|
|
if (TempOutFile)
|
|
Cleanup.push_back(Filename.c_str());
|
|
}
|
|
|
|
/// Return the desired output filename given a base input name, a flag
|
|
/// indicating whether a temp file should be generated, and an optional task id.
|
|
/// The new filename generated is returned in \p NewFilename.
|
|
static void getOutputFileName(SmallString<128> InFilename, bool TempOutFile,
|
|
SmallString<128> &NewFilename, int TaskID) {
|
|
if (TempOutFile) {
|
|
std::error_code EC =
|
|
sys::fs::createTemporaryFile("lto-llvm", "o", NewFilename);
|
|
if (EC)
|
|
message(LDPL_FATAL, "Could not create temporary file: %s",
|
|
EC.message().c_str());
|
|
} else {
|
|
NewFilename = InFilename;
|
|
if (TaskID > 0)
|
|
NewFilename += utostr(TaskID);
|
|
}
|
|
}
|
|
|
|
static CodeGenOpt::Level getCGOptLevel() {
|
|
switch (options::OptLevel) {
|
|
case 0:
|
|
return CodeGenOpt::None;
|
|
case 1:
|
|
return CodeGenOpt::Less;
|
|
case 2:
|
|
return CodeGenOpt::Default;
|
|
case 3:
|
|
return CodeGenOpt::Aggressive;
|
|
}
|
|
llvm_unreachable("Invalid optimization level");
|
|
}
|
|
|
|
/// Parse the thinlto_prefix_replace option into the \p OldPrefix and
|
|
/// \p NewPrefix strings, if it was specified.
|
|
static void getThinLTOOldAndNewPrefix(std::string &OldPrefix,
|
|
std::string &NewPrefix) {
|
|
StringRef PrefixReplace = options::thinlto_prefix_replace;
|
|
assert(PrefixReplace.empty() || PrefixReplace.find(";") != StringRef::npos);
|
|
std::pair<StringRef, StringRef> Split = PrefixReplace.split(";");
|
|
OldPrefix = Split.first.str();
|
|
NewPrefix = Split.second.str();
|
|
}
|
|
|
|
static std::unique_ptr<LTO> createLTO() {
|
|
Config Conf;
|
|
ThinBackend Backend;
|
|
|
|
Conf.CPU = options::mcpu;
|
|
Conf.Options = InitTargetOptionsFromCodeGenFlags();
|
|
|
|
// Disable the new X86 relax relocations since gold might not support them.
|
|
// FIXME: Check the gold version or add a new option to enable them.
|
|
Conf.Options.RelaxELFRelocations = false;
|
|
|
|
// Enable function/data sections by default.
|
|
Conf.Options.FunctionSections = true;
|
|
Conf.Options.DataSections = true;
|
|
|
|
Conf.MAttrs = MAttrs;
|
|
Conf.RelocModel = RelocationModel;
|
|
Conf.CGOptLevel = getCGOptLevel();
|
|
Conf.DisableVerify = options::DisableVerify;
|
|
Conf.OptLevel = options::OptLevel;
|
|
if (options::Parallelism)
|
|
Backend = createInProcessThinBackend(options::Parallelism);
|
|
if (options::thinlto_index_only) {
|
|
std::string OldPrefix, NewPrefix;
|
|
getThinLTOOldAndNewPrefix(OldPrefix, NewPrefix);
|
|
Backend = createWriteIndexesThinBackend(
|
|
OldPrefix, NewPrefix, options::thinlto_emit_imports_files,
|
|
options::thinlto_linked_objects_file);
|
|
}
|
|
|
|
Conf.OverrideTriple = options::triple;
|
|
Conf.DefaultTriple = sys::getDefaultTargetTriple();
|
|
|
|
Conf.DiagHandler = diagnosticHandler;
|
|
|
|
switch (options::TheOutputType) {
|
|
case options::OT_NORMAL:
|
|
break;
|
|
|
|
case options::OT_DISABLE:
|
|
Conf.PreOptModuleHook = [](size_t Task, const Module &M) { return false; };
|
|
break;
|
|
|
|
case options::OT_BC_ONLY:
|
|
Conf.PostInternalizeModuleHook = [](size_t Task, const Module &M) {
|
|
std::error_code EC;
|
|
raw_fd_ostream OS(output_name, EC, sys::fs::OpenFlags::F_None);
|
|
if (EC)
|
|
message(LDPL_FATAL, "Failed to write the output file.");
|
|
WriteBitcodeToFile(&M, OS, /* ShouldPreserveUseListOrder */ false);
|
|
return false;
|
|
};
|
|
break;
|
|
|
|
case options::OT_SAVE_TEMPS:
|
|
check(Conf.addSaveTemps(output_name + ".",
|
|
/* UseInputModulePath */ true));
|
|
break;
|
|
}
|
|
|
|
if (!options::sample_profile.empty())
|
|
Conf.SampleProfile = options::sample_profile;
|
|
|
|
return llvm::make_unique<LTO>(std::move(Conf), Backend,
|
|
options::ParallelCodeGenParallelismLevel);
|
|
}
|
|
|
|
// Write empty files that may be expected by a distributed build
|
|
// system when invoked with thinlto_index_only. This is invoked when
|
|
// the linker has decided not to include the given module in the
|
|
// final link. Frequently the distributed build system will want to
|
|
// confirm that all expected outputs are created based on all of the
|
|
// modules provided to the linker.
|
|
static void writeEmptyDistributedBuildOutputs(std::string &ModulePath,
|
|
std::string &OldPrefix,
|
|
std::string &NewPrefix) {
|
|
std::string NewModulePath =
|
|
getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix);
|
|
std::error_code EC;
|
|
{
|
|
raw_fd_ostream OS(NewModulePath + ".thinlto.bc", EC,
|
|
sys::fs::OpenFlags::F_None);
|
|
if (EC)
|
|
message(LDPL_FATAL, "Failed to write '%s': %s",
|
|
(NewModulePath + ".thinlto.bc").c_str(), EC.message().c_str());
|
|
}
|
|
if (options::thinlto_emit_imports_files) {
|
|
raw_fd_ostream OS(NewModulePath + ".imports", EC,
|
|
sys::fs::OpenFlags::F_None);
|
|
if (EC)
|
|
message(LDPL_FATAL, "Failed to write '%s': %s",
|
|
(NewModulePath + ".imports").c_str(), EC.message().c_str());
|
|
}
|
|
}
|
|
|
|
/// gold informs us that all symbols have been read. At this point, we use
|
|
/// get_symbols to see if any of our definitions have been overridden by a
|
|
/// native object file. Then, perform optimization and codegen.
|
|
static ld_plugin_status allSymbolsReadHook() {
|
|
if (Modules.empty())
|
|
return LDPS_OK;
|
|
|
|
if (unsigned NumOpts = options::extra.size())
|
|
cl::ParseCommandLineOptions(NumOpts, &options::extra[0]);
|
|
|
|
// Map to own RAII objects that manage the file opening and releasing
|
|
// interfaces with gold. This is needed only for ThinLTO mode, since
|
|
// unlike regular LTO, where addModule will result in the opened file
|
|
// being merged into a new combined module, we need to keep these files open
|
|
// through Lto->run().
|
|
DenseMap<void *, std::unique_ptr<PluginInputFile>> HandleToInputFile;
|
|
|
|
std::unique_ptr<LTO> Lto = createLTO();
|
|
|
|
std::string OldPrefix, NewPrefix;
|
|
if (options::thinlto_index_only)
|
|
getThinLTOOldAndNewPrefix(OldPrefix, NewPrefix);
|
|
|
|
std::string OldSuffix, NewSuffix;
|
|
getThinLTOOldAndNewSuffix(OldSuffix, NewSuffix);
|
|
// Set for owning string objects used as buffer identifiers.
|
|
StringSet<> ObjectFilenames;
|
|
|
|
for (claimed_file &F : Modules) {
|
|
if (options::thinlto && !HandleToInputFile.count(F.leader_handle))
|
|
HandleToInputFile.insert(std::make_pair(
|
|
F.leader_handle, llvm::make_unique<PluginInputFile>(F.handle)));
|
|
const void *View = getSymbolsAndView(F);
|
|
// In case we are thin linking with a minimized bitcode file, ensure
|
|
// the module paths encoded in the index reflect where the backends
|
|
// will locate the full bitcode files for compiling/importing.
|
|
std::string Identifier =
|
|
getThinLTOObjectFileName(F.name, OldSuffix, NewSuffix);
|
|
auto ObjFilename = ObjectFilenames.insert(Identifier);
|
|
assert(ObjFilename.second);
|
|
if (!View) {
|
|
if (options::thinlto_index_only)
|
|
// Write empty output files that may be expected by the distributed
|
|
// build system.
|
|
writeEmptyDistributedBuildOutputs(Identifier, OldPrefix, NewPrefix);
|
|
continue;
|
|
}
|
|
addModule(*Lto, F, View, ObjFilename.first->first());
|
|
}
|
|
|
|
SmallString<128> Filename;
|
|
// Note that getOutputFileName will append a unique ID for each task
|
|
if (!options::obj_path.empty())
|
|
Filename = options::obj_path;
|
|
else if (options::TheOutputType == options::OT_SAVE_TEMPS)
|
|
Filename = output_name + ".o";
|
|
bool SaveTemps = !Filename.empty();
|
|
|
|
size_t MaxTasks = Lto->getMaxTasks();
|
|
std::vector<uintptr_t> IsTemporary(MaxTasks);
|
|
std::vector<SmallString<128>> Filenames(MaxTasks);
|
|
|
|
auto AddStream =
|
|
[&](size_t Task) -> std::unique_ptr<lto::NativeObjectStream> {
|
|
IsTemporary[Task] = !SaveTemps;
|
|
getOutputFileName(Filename, /*TempOutFile=*/!SaveTemps, Filenames[Task],
|
|
Task);
|
|
int FD;
|
|
std::error_code EC =
|
|
sys::fs::openFileForWrite(Filenames[Task], FD, sys::fs::F_None);
|
|
if (EC)
|
|
message(LDPL_FATAL, "Could not open file %s: %s", Filenames[Task].c_str(),
|
|
EC.message().c_str());
|
|
return llvm::make_unique<lto::NativeObjectStream>(
|
|
llvm::make_unique<llvm::raw_fd_ostream>(FD, true));
|
|
};
|
|
|
|
auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB) {
|
|
// Note that this requires that the memory buffers provided to AddBuffer are
|
|
// backed by a file.
|
|
Filenames[Task] = MB->getBufferIdentifier();
|
|
};
|
|
|
|
NativeObjectCache Cache;
|
|
if (!options::cache_dir.empty())
|
|
Cache = check(localCache(options::cache_dir, AddBuffer));
|
|
|
|
check(Lto->run(AddStream, Cache));
|
|
|
|
if (options::TheOutputType == options::OT_DISABLE ||
|
|
options::TheOutputType == options::OT_BC_ONLY)
|
|
return LDPS_OK;
|
|
|
|
if (options::thinlto_index_only) {
|
|
if (llvm::AreStatisticsEnabled())
|
|
llvm::PrintStatistics();
|
|
cleanup_hook();
|
|
exit(0);
|
|
}
|
|
|
|
for (unsigned I = 0; I != MaxTasks; ++I)
|
|
if (!Filenames[I].empty())
|
|
recordFile(Filenames[I].str(), IsTemporary[I]);
|
|
|
|
if (!options::extra_library_path.empty() &&
|
|
set_extra_library_path(options::extra_library_path.c_str()) != LDPS_OK)
|
|
message(LDPL_FATAL, "Unable to set the extra library path.");
|
|
|
|
return LDPS_OK;
|
|
}
|
|
|
|
static ld_plugin_status all_symbols_read_hook(void) {
|
|
ld_plugin_status Ret = allSymbolsReadHook();
|
|
llvm_shutdown();
|
|
|
|
if (options::TheOutputType == options::OT_BC_ONLY ||
|
|
options::TheOutputType == options::OT_DISABLE) {
|
|
if (options::TheOutputType == options::OT_DISABLE) {
|
|
// Remove the output file here since ld.bfd creates the output file
|
|
// early.
|
|
std::error_code EC = sys::fs::remove(output_name);
|
|
if (EC)
|
|
message(LDPL_ERROR, "Failed to delete '%s': %s", output_name.c_str(),
|
|
EC.message().c_str());
|
|
}
|
|
exit(0);
|
|
}
|
|
|
|
return Ret;
|
|
}
|
|
|
|
static ld_plugin_status cleanup_hook(void) {
|
|
for (std::string &Name : Cleanup) {
|
|
std::error_code EC = sys::fs::remove(Name);
|
|
if (EC)
|
|
message(LDPL_ERROR, "Failed to delete '%s': %s", Name.c_str(),
|
|
EC.message().c_str());
|
|
}
|
|
|
|
return LDPS_OK;
|
|
}
|