| //===-- gold-plugin.cpp - Plugin to gold for Link Time Optimization ------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This is a gold plugin for LLVM. It provides an LLVM implementation of the |
| // interface described in http://gcc.gnu.org/wiki/whopr/driver . |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/Bitcode/BitcodeReader.h" |
| #include "llvm/Bitcode/BitcodeWriter.h" |
| #include "llvm/CodeGen/CommandFlags.inc" |
| #include "llvm/Config/config.h" // plugin-api.h requires HAVE_STDINT_H |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/DiagnosticPrinter.h" |
| #include "llvm/LTO/Caching.h" |
| #include "llvm/LTO/LTO.h" |
| #include "llvm/Object/Error.h" |
| #include "llvm/Support/CachePruning.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/TargetSelect.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <list> |
| #include <map> |
| #include <plugin-api.h> |
| #include <string> |
| #include <system_error> |
| #include <utility> |
| #include <vector> |
| |
| // FIXME: remove this declaration when we stop maintaining Ubuntu Quantal and |
| // Precise and Debian Wheezy (binutils 2.23 is required) |
| #define LDPO_PIE 3 |
| |
| #define LDPT_GET_SYMBOLS_V3 28 |
| |
| // FIXME: Remove when binutils 2.31 (containing gold 1.16) is the minimum |
| // required version. |
| #define LDPT_GET_WRAP_SYMBOLS 32 |
| |
| using namespace llvm; |
| using namespace lto; |
| |
| // FIXME: Remove when binutils 2.31 (containing gold 1.16) is the minimum |
| // required version. |
| typedef enum ld_plugin_status (*ld_plugin_get_wrap_symbols)( |
| uint64_t *num_symbols, const char ***wrap_symbol_list); |
| |
| static ld_plugin_status discard_message(int level, const char *format, ...) { |
| // Die loudly. Recent versions of Gold pass ld_plugin_message as the first |
| // callback in the transfer vector. This should never be called. |
| abort(); |
| } |
| |
| static ld_plugin_release_input_file release_input_file = nullptr; |
| static ld_plugin_get_input_file get_input_file = nullptr; |
| static ld_plugin_message message = discard_message; |
| static ld_plugin_get_wrap_symbols get_wrap_symbols = nullptr; |
| |
| namespace { |
| struct claimed_file { |
| void *handle; |
| void *leader_handle; |
| std::vector<ld_plugin_symbol> syms; |
| off_t filesize; |
| std::string name; |
| }; |
| |
| /// RAII wrapper to manage opening and releasing of a ld_plugin_input_file. |
| struct PluginInputFile { |
| void *Handle; |
| std::unique_ptr<ld_plugin_input_file> File; |
| |
| PluginInputFile(void *Handle) : Handle(Handle) { |
| File = llvm::make_unique<ld_plugin_input_file>(); |
| if (get_input_file(Handle, File.get()) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to get file information"); |
| } |
| ~PluginInputFile() { |
| // File would have been reset to nullptr if we moved this object |
| // to a new owner. |
| if (File) |
| if (release_input_file(Handle) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to release file information"); |
| } |
| |
| ld_plugin_input_file &file() { return *File; } |
| |
| PluginInputFile(PluginInputFile &&RHS) = default; |
| PluginInputFile &operator=(PluginInputFile &&RHS) = default; |
| }; |
| |
| struct ResolutionInfo { |
| bool CanOmitFromDynSym = true; |
| bool DefaultVisibility = true; |
| bool CanInline = true; |
| bool IsUsedInRegularObj = false; |
| }; |
| |
| } |
| |
| static ld_plugin_add_symbols add_symbols = nullptr; |
| static ld_plugin_get_symbols get_symbols = nullptr; |
| static ld_plugin_add_input_file add_input_file = nullptr; |
| static ld_plugin_set_extra_library_path set_extra_library_path = nullptr; |
| static ld_plugin_get_view get_view = nullptr; |
| static bool IsExecutable = false; |
| static bool SplitSections = true; |
| static Optional<Reloc::Model> RelocationModel = None; |
| static std::string output_name = ""; |
| static std::list<claimed_file> Modules; |
| static DenseMap<int, void *> FDToLeaderHandle; |
| static StringMap<ResolutionInfo> ResInfo; |
| static std::vector<std::string> Cleanup; |
| |
| namespace options { |
| enum OutputType { |
| OT_NORMAL, |
| OT_DISABLE, |
| OT_BC_ONLY, |
| OT_ASM_ONLY, |
| OT_SAVE_TEMPS |
| }; |
| static OutputType TheOutputType = OT_NORMAL; |
| static unsigned OptLevel = 2; |
| // Default parallelism of 0 used to indicate that user did not specify. |
| // Actual parallelism default value depends on implementation. |
| // Currently only affects ThinLTO, where the default is |
| // llvm::heavyweight_hardware_concurrency. |
| static unsigned Parallelism = 0; |
| // Default regular LTO codegen parallelism (number of partitions). |
| static unsigned ParallelCodeGenParallelismLevel = 1; |
| #ifdef NDEBUG |
| static bool DisableVerify = true; |
| #else |
| static bool DisableVerify = false; |
| #endif |
| static std::string obj_path; |
| static std::string extra_library_path; |
| static std::string triple; |
| static std::string mcpu; |
| // When the thinlto plugin option is specified, only read the function |
| // the information from intermediate files and write a combined |
| // global index for the ThinLTO backends. |
| static bool thinlto = false; |
| // If false, all ThinLTO backend compilations through code gen are performed |
| // using multiple threads in the gold-plugin, before handing control back to |
| // gold. If true, write individual backend index files which reflect |
| // the import decisions, and exit afterwards. The assumption is |
| // that the build system will launch the backend processes. |
| static bool thinlto_index_only = false; |
| // If non-empty, holds the name of a file in which to write the list of |
| // oject files gold selected for inclusion in the link after symbol |
| // resolution (i.e. they had selected symbols). This will only be non-empty |
| // in the thinlto_index_only case. It is used to identify files, which may |
| // have originally been within archive libraries specified via |
| // --start-lib/--end-lib pairs, that should be included in the final |
| // native link process (since intervening function importing and inlining |
| // may change the symbol resolution detected in the final link and which |
| // files to include out of --start-lib/--end-lib libraries as a result). |
| static std::string thinlto_linked_objects_file; |
| // If true, when generating individual index files for distributed backends, |
| // also generate a "${bitcodefile}.imports" file at the same location for each |
| // bitcode file, listing the files it imports from in plain text. This is to |
| // support distributed build file staging. |
| static bool thinlto_emit_imports_files = false; |
| // Option to control where files for a distributed backend (the individual |
| // index files and optional imports files) are created. |
| // If specified, expects a string of the form "oldprefix:newprefix", and |
| // instead of generating these files in the same directory path as the |
| // corresponding bitcode file, will use a path formed by replacing the |
| // bitcode file's path prefix matching oldprefix with newprefix. |
| static std::string thinlto_prefix_replace; |
| // Option to control the name of modules encoded in the individual index |
| // files for a distributed backend. This enables the use of minimized |
| // bitcode files for the thin link, assuming the name of the full bitcode |
| // file used in the backend differs just in some part of the file suffix. |
| // If specified, expects a string of the form "oldsuffix:newsuffix". |
| static std::string thinlto_object_suffix_replace; |
| // Optional path to a directory for caching ThinLTO objects. |
| static std::string cache_dir; |
| // Optional pruning policy for ThinLTO caches. |
| static std::string cache_policy; |
| // Additional options to pass into the code generator. |
| // Note: This array will contain all plugin options which are not claimed |
| // as plugin exclusive to pass to the code generator. |
| static std::vector<const char *> extra; |
| // Sample profile file path |
| static std::string sample_profile; |
| // New pass manager |
| static bool new_pass_manager = false; |
| // Debug new pass manager |
| static bool debug_pass_manager = false; |
| // Directory to store the .dwo files. |
| static std::string dwo_dir; |
| /// Statistics output filename. |
| static std::string stats_file; |
| |
| // Optimization remarks filename and hotness options |
| static std::string OptRemarksFilename; |
| static bool OptRemarksWithHotness = false; |
| |
| static void process_plugin_option(const char *opt_) |
| { |
| if (opt_ == nullptr) |
| return; |
| llvm::StringRef opt = opt_; |
| |
| if (opt.startswith("mcpu=")) { |
| mcpu = opt.substr(strlen("mcpu=")); |
| } else if (opt.startswith("extra-library-path=")) { |
| extra_library_path = opt.substr(strlen("extra_library_path=")); |
| } else if (opt.startswith("mtriple=")) { |
| triple = opt.substr(strlen("mtriple=")); |
| } else if (opt.startswith("obj-path=")) { |
| obj_path = opt.substr(strlen("obj-path=")); |
| } else if (opt == "emit-llvm") { |
| TheOutputType = OT_BC_ONLY; |
| } else if (opt == "save-temps") { |
| TheOutputType = OT_SAVE_TEMPS; |
| } else if (opt == "disable-output") { |
| TheOutputType = OT_DISABLE; |
| } else if (opt == "emit-asm") { |
| TheOutputType = OT_ASM_ONLY; |
| } else if (opt == "thinlto") { |
| thinlto = true; |
| } else if (opt == "thinlto-index-only") { |
| thinlto_index_only = true; |
| } else if (opt.startswith("thinlto-index-only=")) { |
| thinlto_index_only = true; |
| thinlto_linked_objects_file = opt.substr(strlen("thinlto-index-only=")); |
| } else if (opt == "thinlto-emit-imports-files") { |
| thinlto_emit_imports_files = true; |
| } else if (opt.startswith("thinlto-prefix-replace=")) { |
| thinlto_prefix_replace = opt.substr(strlen("thinlto-prefix-replace=")); |
| if (thinlto_prefix_replace.find(';') == std::string::npos) |
| message(LDPL_FATAL, "thinlto-prefix-replace expects 'old;new' format"); |
| } else if (opt.startswith("thinlto-object-suffix-replace=")) { |
| thinlto_object_suffix_replace = |
| opt.substr(strlen("thinlto-object-suffix-replace=")); |
| if (thinlto_object_suffix_replace.find(';') == std::string::npos) |
| message(LDPL_FATAL, |
| "thinlto-object-suffix-replace expects 'old;new' format"); |
| } else if (opt.startswith("cache-dir=")) { |
| cache_dir = opt.substr(strlen("cache-dir=")); |
| } else if (opt.startswith("cache-policy=")) { |
| cache_policy = opt.substr(strlen("cache-policy=")); |
| } else if (opt.size() == 2 && opt[0] == 'O') { |
| if (opt[1] < '0' || opt[1] > '3') |
| message(LDPL_FATAL, "Optimization level must be between 0 and 3"); |
| OptLevel = opt[1] - '0'; |
| } else if (opt.startswith("jobs=")) { |
| if (StringRef(opt_ + 5).getAsInteger(10, Parallelism)) |
| message(LDPL_FATAL, "Invalid parallelism level: %s", opt_ + 5); |
| } else if (opt.startswith("lto-partitions=")) { |
| if (opt.substr(strlen("lto-partitions=")) |
| .getAsInteger(10, ParallelCodeGenParallelismLevel)) |
| message(LDPL_FATAL, "Invalid codegen partition level: %s", opt_ + 5); |
| } else if (opt == "disable-verify") { |
| DisableVerify = true; |
| } else if (opt.startswith("sample-profile=")) { |
| sample_profile= opt.substr(strlen("sample-profile=")); |
| } else if (opt == "new-pass-manager") { |
| new_pass_manager = true; |
| } else if (opt == "debug-pass-manager") { |
| debug_pass_manager = true; |
| } else if (opt.startswith("dwo_dir=")) { |
| dwo_dir = opt.substr(strlen("dwo_dir=")); |
| } else if (opt.startswith("opt-remarks-filename=")) { |
| OptRemarksFilename = opt.substr(strlen("opt-remarks-filename=")); |
| } else if (opt == "opt-remarks-with-hotness") { |
| OptRemarksWithHotness = true; |
| } else if (opt.startswith("stats-file=")) { |
| stats_file = opt.substr(strlen("stats-file=")); |
| } else { |
| // Save this option to pass to the code generator. |
| // ParseCommandLineOptions() expects argv[0] to be program name. Lazily |
| // add that. |
| if (extra.empty()) |
| extra.push_back("LLVMgold"); |
| |
| extra.push_back(opt_); |
| } |
| } |
| } |
| |
| static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file, |
| int *claimed); |
| static ld_plugin_status all_symbols_read_hook(void); |
| static ld_plugin_status cleanup_hook(void); |
| |
| extern "C" ld_plugin_status onload(ld_plugin_tv *tv); |
| ld_plugin_status onload(ld_plugin_tv *tv) { |
| InitializeAllTargetInfos(); |
| InitializeAllTargets(); |
| InitializeAllTargetMCs(); |
| InitializeAllAsmParsers(); |
| InitializeAllAsmPrinters(); |
| |
| // We're given a pointer to the first transfer vector. We read through them |
| // until we find one where tv_tag == LDPT_NULL. The REGISTER_* tagged values |
| // contain pointers to functions that we need to call to register our own |
| // hooks. The others are addresses of functions we can use to call into gold |
| // for services. |
| |
| bool registeredClaimFile = false; |
| bool RegisteredAllSymbolsRead = false; |
| |
| for (; tv->tv_tag != LDPT_NULL; ++tv) { |
| // Cast tv_tag to int to allow values not in "enum ld_plugin_tag", like, for |
| // example, LDPT_GET_SYMBOLS_V3 when building against an older plugin-api.h |
| // header. |
| switch (static_cast<int>(tv->tv_tag)) { |
| case LDPT_OUTPUT_NAME: |
| output_name = tv->tv_u.tv_string; |
| break; |
| case LDPT_LINKER_OUTPUT: |
| switch (tv->tv_u.tv_val) { |
| case LDPO_REL: // .o |
| IsExecutable = false; |
| SplitSections = false; |
| break; |
| case LDPO_DYN: // .so |
| IsExecutable = false; |
| RelocationModel = Reloc::PIC_; |
| break; |
| case LDPO_PIE: // position independent executable |
| IsExecutable = true; |
| RelocationModel = Reloc::PIC_; |
| break; |
| case LDPO_EXEC: // .exe |
| IsExecutable = true; |
| RelocationModel = Reloc::Static; |
| break; |
| default: |
| message(LDPL_ERROR, "Unknown output file type %d", tv->tv_u.tv_val); |
| return LDPS_ERR; |
| } |
| break; |
| case LDPT_OPTION: |
| options::process_plugin_option(tv->tv_u.tv_string); |
| break; |
| case LDPT_REGISTER_CLAIM_FILE_HOOK: { |
| ld_plugin_register_claim_file callback; |
| callback = tv->tv_u.tv_register_claim_file; |
| |
| if (callback(claim_file_hook) != LDPS_OK) |
| return LDPS_ERR; |
| |
| registeredClaimFile = true; |
| } break; |
| case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: { |
| ld_plugin_register_all_symbols_read callback; |
| callback = tv->tv_u.tv_register_all_symbols_read; |
| |
| if (callback(all_symbols_read_hook) != LDPS_OK) |
| return LDPS_ERR; |
| |
| RegisteredAllSymbolsRead = true; |
| } break; |
| case LDPT_REGISTER_CLEANUP_HOOK: { |
| ld_plugin_register_cleanup callback; |
| callback = tv->tv_u.tv_register_cleanup; |
| |
| if (callback(cleanup_hook) != LDPS_OK) |
| return LDPS_ERR; |
| } break; |
| case LDPT_GET_INPUT_FILE: |
| get_input_file = tv->tv_u.tv_get_input_file; |
| break; |
| case LDPT_RELEASE_INPUT_FILE: |
| release_input_file = tv->tv_u.tv_release_input_file; |
| break; |
| case LDPT_ADD_SYMBOLS: |
| add_symbols = tv->tv_u.tv_add_symbols; |
| break; |
| case LDPT_GET_SYMBOLS_V2: |
| // Do not override get_symbols_v3 with get_symbols_v2. |
| if (!get_symbols) |
| get_symbols = tv->tv_u.tv_get_symbols; |
| break; |
| case LDPT_GET_SYMBOLS_V3: |
| get_symbols = tv->tv_u.tv_get_symbols; |
| break; |
| case LDPT_ADD_INPUT_FILE: |
| add_input_file = tv->tv_u.tv_add_input_file; |
| break; |
| case LDPT_SET_EXTRA_LIBRARY_PATH: |
| set_extra_library_path = tv->tv_u.tv_set_extra_library_path; |
| break; |
| case LDPT_GET_VIEW: |
| get_view = tv->tv_u.tv_get_view; |
| break; |
| case LDPT_MESSAGE: |
| message = tv->tv_u.tv_message; |
| break; |
| case LDPT_GET_WRAP_SYMBOLS: |
| // FIXME: When binutils 2.31 (containing gold 1.16) is the minimum |
| // required version, this should be changed to: |
| // get_wrap_symbols = tv->tv_u.tv_get_wrap_symbols; |
| get_wrap_symbols = |
| (ld_plugin_get_wrap_symbols)tv->tv_u.tv_message; |
| break; |
| default: |
| break; |
| } |
| } |
| |
| if (!registeredClaimFile) { |
| message(LDPL_ERROR, "register_claim_file not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| if (!add_symbols) { |
| message(LDPL_ERROR, "add_symbols not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| |
| if (!RegisteredAllSymbolsRead) |
| return LDPS_OK; |
| |
| if (!get_input_file) { |
| message(LDPL_ERROR, "get_input_file not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| if (!release_input_file) { |
| message(LDPL_ERROR, "release_input_file not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| |
| return LDPS_OK; |
| } |
| |
| static void diagnosticHandler(const DiagnosticInfo &DI) { |
| std::string ErrStorage; |
| { |
| raw_string_ostream OS(ErrStorage); |
| DiagnosticPrinterRawOStream DP(OS); |
| DI.print(DP); |
| } |
| ld_plugin_level Level; |
| switch (DI.getSeverity()) { |
| case DS_Error: |
| Level = LDPL_FATAL; |
| break; |
| case DS_Warning: |
| Level = LDPL_WARNING; |
| break; |
| case DS_Note: |
| case DS_Remark: |
| Level = LDPL_INFO; |
| break; |
| } |
| message(Level, "LLVM gold plugin: %s", ErrStorage.c_str()); |
| } |
| |
| static void check(Error E, std::string Msg = "LLVM gold plugin") { |
| handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) -> Error { |
| message(LDPL_FATAL, "%s: %s", Msg.c_str(), EIB.message().c_str()); |
| return Error::success(); |
| }); |
| } |
| |
| template <typename T> static T check(Expected<T> E) { |
| if (E) |
| return std::move(*E); |
| check(E.takeError()); |
| return T(); |
| } |
| |
| /// Called by gold to see whether this file is one that our plugin can handle. |
| /// We'll try to open it and register all the symbols with add_symbol if |
| /// possible. |
| static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file, |
| int *claimed) { |
| MemoryBufferRef BufferRef; |
| std::unique_ptr<MemoryBuffer> Buffer; |
| if (get_view) { |
| const void *view; |
| if (get_view(file->handle, &view) != LDPS_OK) { |
| message(LDPL_ERROR, "Failed to get a view of %s", file->name); |
| return LDPS_ERR; |
| } |
| BufferRef = |
| MemoryBufferRef(StringRef((const char *)view, file->filesize), ""); |
| } else { |
| int64_t offset = 0; |
| // Gold has found what might be IR part-way inside of a file, such as |
| // an .a archive. |
| if (file->offset) { |
| offset = file->offset; |
| } |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = |
| MemoryBuffer::getOpenFileSlice(file->fd, file->name, file->filesize, |
| offset); |
| if (std::error_code EC = BufferOrErr.getError()) { |
| message(LDPL_ERROR, EC.message().c_str()); |
| return LDPS_ERR; |
| } |
| Buffer = std::move(BufferOrErr.get()); |
| BufferRef = Buffer->getMemBufferRef(); |
| } |
| |
| *claimed = 1; |
| |
| Expected<std::unique_ptr<InputFile>> ObjOrErr = InputFile::create(BufferRef); |
| 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; |
| } |
| } |
| |
| // Handle any --wrap options passed to gold, which are than passed |
| // along to the plugin. |
| if (get_wrap_symbols) { |
| const char **wrap_symbols; |
| uint64_t count = 0; |
| if (get_wrap_symbols(&count, &wrap_symbols) != LDPS_OK) { |
| message(LDPL_ERROR, "Unable to get wrap symbols!"); |
| return LDPS_ERR; |
| } |
| for (uint64_t i = 0; i < count; i++) { |
| StringRef Name = wrap_symbols[i]; |
| ResolutionInfo &Res = ResInfo[Name]; |
| ResolutionInfo &WrapRes = ResInfo["__wrap_" + Name.str()]; |
| ResolutionInfo &RealRes = ResInfo["__real_" + Name.str()]; |
| // Tell LTO not to inline symbols that will be overwritten. |
| Res.CanInline = false; |
| RealRes.CanInline = false; |
| // Tell LTO not to eliminate symbols that will be used after renaming. |
| Res.IsUsedInRegularObj = true; |
| WrapRes.IsUsedInRegularObj = true; |
| } |
| } |
| |
| 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::tie(OldSuffix, NewSuffix) = SuffixReplace.split(';'); |
| } |
| |
| /// Given the original \p Path to an output file, replace any filename |
| /// suffix matching \p OldSuffix with \p NewSuffix. |
| static std::string getThinLTOObjectFileName(StringRef Path, StringRef OldSuffix, |
| StringRef NewSuffix) { |
| if (Path.consume_back(OldSuffix)) |
| return (Path + NewSuffix).str(); |
| return Path; |
| } |
| |
| // Returns true if S is valid as a C language identifier. |
| static bool isValidCIdentifier(StringRef S) { |
| return !S.empty() && (isAlpha(S[0]) || S[0] == '_') && |
| std::all_of(S.begin() + 1, S.end(), |
| [](char C) { return C == '_' || isAlnum(C); }); |
| } |
| |
| static bool isUndefined(ld_plugin_symbol &Sym) { |
| return Sym.def == LDPK_UNDEF || Sym.def == LDPK_WEAKUNDEF; |
| } |
| |
| 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 = !isUndefined(Sym); |
| break; |
| |
| case LDPR_PREVAILING_DEF: |
| R.Prevailing = !isUndefined(Sym); |
| R.VisibleToRegularObj = true; |
| break; |
| |
| case LDPR_PREVAILING_DEF_IRONLY_EXP: |
| R.Prevailing = !isUndefined(Sym); |
| 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; |
| |
| if (!Res.CanInline) |
| R.LinkerRedefined = true; |
| |
| if (Res.IsUsedInRegularObj) |
| R.VisibleToRegularObj = true; |
| |
| freeSymName(Sym); |
| } |
| |
| check(Lto.add(std::move(Input), Resols), |
| std::string("Failed to link module ") + F.name); |
| } |
| |
| static void recordFile(const 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); |
| } |
| |
| /// 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 int getOutputFileName(StringRef InFilename, bool TempOutFile, |
| SmallString<128> &NewFilename, int TaskID) { |
| int FD = -1; |
| if (TempOutFile) { |
| std::error_code EC = |
| sys::fs::createTemporaryFile("lto-llvm", "o", FD, 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); |
| std::error_code EC = |
| sys::fs::openFileForWrite(NewFilename, FD, sys::fs::CD_CreateAlways); |
| if (EC) |
| message(LDPL_FATAL, "Could not open file %s: %s", NewFilename.c_str(), |
| EC.message().c_str()); |
| } |
| return FD; |
| } |
| |
| 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::tie(OldPrefix, NewPrefix) = PrefixReplace.split(';'); |
| } |
| |
| /// Creates instance of LTO. |
| /// OnIndexWrite is callback to let caller know when LTO writes index files. |
| /// LinkedObjectsFile is an output stream to write the list of object files for |
| /// the final ThinLTO linking. Can be nullptr. |
| static std::unique_ptr<LTO> createLTO(IndexWriteCallback OnIndexWrite, |
| raw_fd_ostream *LinkedObjectsFile) { |
| 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; |
| |
| // Toggle function/data sections. |
| if (FunctionSections.getNumOccurrences() == 0) |
| Conf.Options.FunctionSections = SplitSections; |
| if (DataSections.getNumOccurrences() == 0) |
| Conf.Options.DataSections = SplitSections; |
| |
| Conf.MAttrs = MAttrs; |
| Conf.RelocModel = RelocationModel; |
| Conf.CodeModel = getCodeModel(); |
| 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, |
| LinkedObjectsFile, OnIndexWrite); |
| } |
| |
| 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; |
| case options::OT_ASM_ONLY: |
| Conf.CGFileType = TargetMachine::CGFT_AssemblyFile; |
| break; |
| } |
| |
| if (!options::sample_profile.empty()) |
| Conf.SampleProfile = options::sample_profile; |
| |
| Conf.DwoDir = options::dwo_dir; |
| |
| // Set up optimization remarks handling. |
| Conf.RemarksFilename = options::OptRemarksFilename; |
| Conf.RemarksWithHotness = options::OptRemarksWithHotness; |
| |
| // Use new pass manager if set in driver |
| Conf.UseNewPM = options::new_pass_manager; |
| // Debug new pass manager if requested |
| Conf.DebugPassManager = options::debug_pass_manager; |
| |
| Conf.StatsFile = options::stats_file; |
| 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. |
| // If SkipModule is true then .thinlto.bc should contain just |
| // SkipModuleByDistributedBackend flag which requests distributed backend |
| // to skip the compilation of the corresponding module and produce an empty |
| // object file. |
| static void writeEmptyDistributedBuildOutputs(const std::string &ModulePath, |
| const std::string &OldPrefix, |
| const std::string &NewPrefix, |
| bool SkipModule) { |
| 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 (SkipModule) { |
| ModuleSummaryIndex Index(/*HaveGVs*/ false); |
| Index.setSkipModuleByDistributedBackend(); |
| WriteIndexToFile(Index, OS, nullptr); |
| } |
| } |
| 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()); |
| } |
| } |
| |
| // Creates and returns output stream with a list of object files for final |
| // linking of distributed ThinLTO. |
| static std::unique_ptr<raw_fd_ostream> CreateLinkedObjectsFile() { |
| if (options::thinlto_linked_objects_file.empty()) |
| return nullptr; |
| assert(options::thinlto_index_only); |
| std::error_code EC; |
| auto LinkedObjectsFile = llvm::make_unique<raw_fd_ostream>( |
| options::thinlto_linked_objects_file, EC, sys::fs::OpenFlags::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Failed to create '%s': %s", |
| options::thinlto_linked_objects_file.c_str(), EC.message().c_str()); |
| return LinkedObjectsFile; |
| } |
| |
| /// Runs LTO and return a list of pairs <FileName, IsTemporary>. |
| static std::vector<std::pair<SmallString<128>, bool>> runLTO() { |
| // 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; |
| |
| // Owns string objects and tells if index file was already created. |
| StringMap<bool> ObjectToIndexFileState; |
| |
| std::unique_ptr<raw_fd_ostream> LinkedObjects = CreateLinkedObjectsFile(); |
| std::unique_ptr<LTO> Lto = createLTO( |
| [&ObjectToIndexFileState](const std::string &Identifier) { |
| ObjectToIndexFileState[Identifier] = true; |
| }, |
| LinkedObjects.get()); |
| |
| std::string OldPrefix, NewPrefix; |
| if (options::thinlto_index_only) |
| getThinLTOOldAndNewPrefix(OldPrefix, NewPrefix); |
| |
| std::string OldSuffix, NewSuffix; |
| getThinLTOOldAndNewSuffix(OldSuffix, NewSuffix); |
| |
| 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))); |
| // 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 = ObjectToIndexFileState.insert({Identifier, false}); |
| assert(ObjFilename.second); |
| if (const void *View = getSymbolsAndView(F)) |
| addModule(*Lto, F, View, ObjFilename.first->first()); |
| else if (options::thinlto_index_only) { |
| ObjFilename.first->second = true; |
| writeEmptyDistributedBuildOutputs(Identifier, OldPrefix, NewPrefix, |
| /* SkipModule */ true); |
| } |
| } |
| |
| 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"; |
| else if (options::TheOutputType == options::OT_ASM_ONLY) |
| Filename = output_name; |
| bool SaveTemps = !Filename.empty(); |
| |
| size_t MaxTasks = Lto->getMaxTasks(); |
| std::vector<std::pair<SmallString<128>, bool>> Files(MaxTasks); |
| |
| auto AddStream = |
| [&](size_t Task) -> std::unique_ptr<lto::NativeObjectStream> { |
| Files[Task].second = !SaveTemps; |
| int FD = getOutputFileName(Filename, /* TempOutFile */ !SaveTemps, |
| Files[Task].first, Task); |
| 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) { |
| *AddStream(Task)->OS << MB->getBuffer(); |
| }; |
| |
| NativeObjectCache Cache; |
| if (!options::cache_dir.empty()) |
| Cache = check(localCache(options::cache_dir, AddBuffer)); |
| |
| check(Lto->run(AddStream, Cache)); |
| |
| // Write empty output files that may be expected by the distributed build |
| // system. |
| if (options::thinlto_index_only) |
| for (auto &Identifier : ObjectToIndexFileState) |
| if (!Identifier.getValue()) |
| writeEmptyDistributedBuildOutputs(Identifier.getKey(), OldPrefix, |
| NewPrefix, /* SkipModule */ false); |
| |
| return Files; |
| } |
| |
| /// 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]); |
| |
| std::vector<std::pair<SmallString<128>, bool>> Files = runLTO(); |
| |
| if (options::TheOutputType == options::OT_DISABLE || |
| options::TheOutputType == options::OT_BC_ONLY || |
| options::TheOutputType == options::OT_ASM_ONLY) |
| return LDPS_OK; |
| |
| if (options::thinlto_index_only) { |
| llvm_shutdown(); |
| cleanup_hook(); |
| exit(0); |
| } |
| |
| for (const auto &F : Files) |
| if (!F.first.empty()) |
| recordFile(F.first.str(), F.second); |
| |
| 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_ASM_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()); |
| } |
| |
| // Prune cache |
| if (!options::cache_dir.empty()) { |
| CachePruningPolicy policy = check(parseCachePruningPolicy(options::cache_policy)); |
| pruneCache(options::cache_dir, policy); |
| } |
| |
| return LDPS_OK; |
| } |