llvm/tools/gold/gold-plugin.cpp

   1 //===-- gold-plugin.cpp - Plugin to gold for Link Time Optimization  ------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This is a gold plugin for LLVM. It provides an LLVM implementation of the
  10 // interface described in http://gcc.gnu.org/wiki/whopr/driver .
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ADT/Statistic.h"
  15 #include "llvm/Bitcode/BitcodeReader.h"
  16 #include "llvm/Bitcode/BitcodeWriter.h"
  17 #include "llvm/CodeGen/CommandFlags.h"
  18 #include "llvm/Config/config.h" // plugin-api.h requires HAVE_STDINT_H
  19 #include "llvm/Config/llvm-config.h"
  20 #include "llvm/IR/Constants.h"
  21 #include "llvm/IR/DiagnosticPrinter.h"
  22 #include "llvm/LTO/LTO.h"
  23 #include "llvm/Object/Error.h"
  24 #include "llvm/Remarks/HotnessThresholdParser.h"
  25 #include "llvm/Support/CachePruning.h"
  26 #include "llvm/Support/Caching.h"
  27 #include "llvm/Support/CommandLine.h"
  28 #include "llvm/Support/FileSystem.h"
  29 #include "llvm/Support/ManagedStatic.h"
  30 #include "llvm/Support/MemoryBuffer.h"
  31 #include "llvm/Support/Path.h"
  32 #include "llvm/Support/TargetSelect.h"
  33 #include "llvm/Support/Threading.h"
  34 #include "llvm/Support/raw_ostream.h"
  35 #include "llvm/TargetParser/Host.h"
  36 #include <list>
  37 #include <map>
  38 #include <plugin-api.h>
  39 #include <string>
  40 #include <system_error>
  41 #include <utility>
  42 #include <vector>
  43
  44 // FIXME: remove this declaration when we stop maintaining Ubuntu Quantal and
  45 // Precise and Debian Wheezy (binutils 2.23 is required)
  46 #define LDPO_PIE 3
  47
  48 #define LDPT_GET_SYMBOLS_V3 28
  49
  50 // FIXME: Remove when binutils 2.31 (containing gold 1.16) is the minimum
  51 // required version.
  52 #define LDPT_GET_WRAP_SYMBOLS 32
  53
  54 using namespace llvm;
  55 using namespace lto;
  56
  57 static codegen::RegisterCodeGenFlags CodeGenFlags;
  58
  59 // FIXME: Remove when binutils 2.31 (containing gold 1.16) is the minimum
  60 // required version.
  61 typedef enum ld_plugin_status (*ld_plugin_get_wrap_symbols)(
  62     uint64_t *num_symbols, const char ***wrap_symbol_list);
  63
  64 static ld_plugin_status discard_message(int level, const char *format, ...) {
  65   // Die loudly. Recent versions of Gold pass ld_plugin_message as the first
  66   // callback in the transfer vector. This should never be called.
  67   abort();
  68 }
  69
  70 static ld_plugin_release_input_file release_input_file = nullptr;
  71 static ld_plugin_get_input_file get_input_file = nullptr;
  72 static ld_plugin_message message = discard_message;
  73 static ld_plugin_get_wrap_symbols get_wrap_symbols = nullptr;
  74
  75 namespace {
  76 struct claimed_file {
  77   void *handle;
  78   void *leader_handle;
  79   std::vector<ld_plugin_symbol> syms;
  80   off_t filesize;
  81   std::string name;
  82 };
  83
  84 /// RAII wrapper to manage opening and releasing of a ld_plugin_input_file.
  85 struct PluginInputFile {
  86   void *Handle;
  87   std::unique_ptr<ld_plugin_input_file> File;
  88
  89   PluginInputFile(void *Handle) : Handle(Handle) {
  90     File = std::make_unique<ld_plugin_input_file>();
  91     if (get_input_file(Handle, File.get()) != LDPS_OK)
  92       message(LDPL_FATAL, "Failed to get file information");
  93   }
  94   ~PluginInputFile() {
  95     // File would have been reset to nullptr if we moved this object
  96     // to a new owner.
  97     if (File)
  98       if (release_input_file(Handle) != LDPS_OK)
  99         message(LDPL_FATAL, "Failed to release file information");
 100   }
 101
 102   ld_plugin_input_file &file() { return *File; }
 103
 104   PluginInputFile(PluginInputFile &&RHS) = default;
 105   PluginInputFile &operator=(PluginInputFile &&RHS) = default;
 106 };
 107
 108 struct ResolutionInfo {
 109   bool CanOmitFromDynSym = true;
 110   bool DefaultVisibility = true;
 111   bool CanInline = true;
 112   bool IsUsedInRegularObj = false;
 113 };
 114
 115 }
 116
 117 static ld_plugin_add_symbols add_symbols = nullptr;
 118 static ld_plugin_get_symbols get_symbols = nullptr;
 119 static ld_plugin_add_input_file add_input_file = nullptr;
 120 static ld_plugin_set_extra_library_path set_extra_library_path = nullptr;
 121 static ld_plugin_get_view get_view = nullptr;
 122 static bool IsExecutable = false;
 123 static bool SplitSections = true;
 124 static std::optional<Reloc::Model> RelocationModel;
 125 static std::string output_name = "";
 126 static std::list<claimed_file> Modules;
 127 static DenseMap<int, void *> FDToLeaderHandle;
 128 static StringMap<ResolutionInfo> ResInfo;
 129 static std::vector<std::string> Cleanup;
 130
 131 namespace options {
 132   enum OutputType {
 133     OT_NORMAL,
 134     OT_DISABLE,
 135     OT_BC_ONLY,
 136     OT_ASM_ONLY,
 137     OT_SAVE_TEMPS
 138   };
 139   static OutputType TheOutputType = OT_NORMAL;
 140   static unsigned OptLevel = 2;
 141   // Currently only affects ThinLTO, where the default is the max cores in the
 142   // system. See llvm::get_threadpool_strategy() for acceptable values.
 143   static std::string Parallelism;
 144   // Default regular LTO codegen parallelism (number of partitions).
 145   static unsigned ParallelCodeGenParallelismLevel = 1;
 146 #ifdef NDEBUG
 147   static bool DisableVerify = true;
 148 #else
 149   static bool DisableVerify = false;
 150 #endif
 151   static std::string obj_path;
 152   static std::string extra_library_path;
 153   static std::string triple;
 154   static std::string mcpu;
 155   // When the thinlto plugin option is specified, only read the function
 156   // the information from intermediate files and write a combined
 157   // global index for the ThinLTO backends.
 158   static bool thinlto = false;
 159   // If false, all ThinLTO backend compilations through code gen are performed
 160   // using multiple threads in the gold-plugin, before handing control back to
 161   // gold. If true, write individual backend index files which reflect
 162   // the import decisions, and exit afterwards. The assumption is
 163   // that the build system will launch the backend processes.
 164   static bool thinlto_index_only = false;
 165   // If non-empty, holds the name of a file in which to write the list of
 166   // oject files gold selected for inclusion in the link after symbol
 167   // resolution (i.e. they had selected symbols). This will only be non-empty
 168   // in the thinlto_index_only case. It is used to identify files, which may
 169   // have originally been within archive libraries specified via
 170   // --start-lib/--end-lib pairs, that should be included in the final
 171   // native link process (since intervening function importing and inlining
 172   // may change the symbol resolution detected in the final link and which
 173   // files to include out of --start-lib/--end-lib libraries as a result).
 174   static std::string thinlto_linked_objects_file;
 175   // If true, when generating individual index files for distributed backends,
 176   // also generate a "${bitcodefile}.imports" file at the same location for each
 177   // bitcode file, listing the files it imports from in plain text. This is to
 178   // support distributed build file staging.
 179   static bool thinlto_emit_imports_files = false;
 180   // Option to control where files for a distributed backend (the individual
 181   // index files and optional imports files) are created.
 182   // If specified, expects a string of the form "oldprefix:newprefix", and
 183   // instead of generating these files in the same directory path as the
 184   // corresponding bitcode file, will use a path formed by replacing the
 185   // bitcode file's path prefix matching oldprefix with newprefix.
 186   static std::string thinlto_prefix_replace;
 187   // Option to control the name of modules encoded in the individual index
 188   // files for a distributed backend. This enables the use of minimized
 189   // bitcode files for the thin link, assuming the name of the full bitcode
 190   // file used in the backend differs just in some part of the file suffix.
 191   // If specified, expects a string of the form "oldsuffix:newsuffix".
 192   static std::string thinlto_object_suffix_replace;
 193   // Optional path to a directory for caching ThinLTO objects.
 194   static std::string cache_dir;
 195   // Optional pruning policy for ThinLTO caches.
 196   static std::string cache_policy;
 197   // Additional options to pass into the code generator.
 198   // Note: This array will contain all plugin options which are not claimed
 199   // as plugin exclusive to pass to the code generator.
 200   static std::vector<const char *> extra;
 201   // Sample profile file path
 202   static std::string sample_profile;
 203   // Debug new pass manager
 204   static bool debug_pass_manager = false;
 205   // Directory to store the .dwo files.
 206   static std::string dwo_dir;
 207   /// Statistics output filename.
 208   static std::string stats_file;
 209   // Asserts that LTO link has whole program visibility
 210   static bool whole_program_visibility = false;
 211
 212   // Optimization remarks filename, accepted passes and hotness options
 213   static std::string RemarksFilename;
 214   static std::string RemarksPasses;
 215   static bool RemarksWithHotness = false;
 216   static std::optional<uint64_t> RemarksHotnessThreshold = 0;
 217   static std::string RemarksFormat;
 218
 219   // Context sensitive PGO options.
 220   static std::string cs_profile_path;
 221   static bool cs_pgo_gen = false;
 222
 223   static void process_plugin_option(const char *opt_)
 224   {
 225     if (opt_ == nullptr)
 226       return;
 227     llvm::StringRef opt = opt_;
 228
 229     if (opt.consume_front("mcpu=")) {
 230       mcpu = std::string(opt);
 231     } else if (opt.consume_front("extra-library-path=")) {
 232       extra_library_path = std::string(opt);
 233     } else if (opt.consume_front("mtriple=")) {
 234       triple = std::string(opt);
 235     } else if (opt.consume_front("obj-path=")) {
 236       obj_path = std::string(opt);
 237     } else if (opt == "emit-llvm") {
 238       TheOutputType = OT_BC_ONLY;
 239     } else if (opt == "save-temps") {
 240       TheOutputType = OT_SAVE_TEMPS;
 241     } else if (opt == "disable-output") {
 242       TheOutputType = OT_DISABLE;
 243     } else if (opt == "emit-asm") {
 244       TheOutputType = OT_ASM_ONLY;
 245     } else if (opt == "thinlto") {
 246       thinlto = true;
 247     } else if (opt == "thinlto-index-only") {
 248       thinlto_index_only = true;
 249     } else if (opt.consume_front("thinlto-index-only=")) {
 250       thinlto_index_only = true;
 251       thinlto_linked_objects_file = std::string(opt);
 252     } else if (opt == "thinlto-emit-imports-files") {
 253       thinlto_emit_imports_files = true;
 254     } else if (opt.consume_front("thinlto-prefix-replace=")) {
 255       thinlto_prefix_replace = std::string(opt);
 256       if (thinlto_prefix_replace.find(';') == std::string::npos)
 257         message(LDPL_FATAL, "thinlto-prefix-replace expects 'old;new' format");
 258     } else if (opt.consume_front("thinlto-object-suffix-replace=")) {
 259       thinlto_object_suffix_replace = std::string(opt);
 260       if (thinlto_object_suffix_replace.find(';') == std::string::npos)
 261         message(LDPL_FATAL,
 262                 "thinlto-object-suffix-replace expects 'old;new' format");
 263     } else if (opt.consume_front("cache-dir=")) {
 264       cache_dir = std::string(opt);
 265     } else if (opt.consume_front("cache-policy=")) {
 266       cache_policy = std::string(opt);
 267     } else if (opt.size() == 2 && opt[0] == 'O') {
 268       if (opt[1] < '0' || opt[1] > '3')
 269         message(LDPL_FATAL, "Optimization level must be between 0 and 3");
 270       OptLevel = opt[1] - '0';
 271     } else if (opt.consume_front("jobs=")) {
 272       Parallelism = std::string(opt);
 273       if (!get_threadpool_strategy(opt))
 274         message(LDPL_FATAL, "Invalid parallelism level: %s",
 275                 Parallelism.c_str());
 276     } else if (opt.consume_front("lto-partitions=")) {
 277       if (opt.getAsInteger(10, ParallelCodeGenParallelismLevel))
 278         message(LDPL_FATAL, "Invalid codegen partition level: %s", opt_ + 5);
 279     } else if (opt == "disable-verify") {
 280       DisableVerify = true;
 281     } else if (opt.consume_front("sample-profile=")) {
 282       sample_profile = std::string(opt);
 283     } else if (opt == "cs-profile-generate") {
 284       cs_pgo_gen = true;
 285     } else if (opt.consume_front("cs-profile-path=")) {
 286       cs_profile_path = std::string(opt);
 287     } else if (opt == "new-pass-manager") {
 288       // We always use the new pass manager.
 289     } else if (opt == "debug-pass-manager") {
 290       debug_pass_manager = true;
 291     } else if (opt == "whole-program-visibility") {
 292       whole_program_visibility = true;
 293     } else if (opt.consume_front("dwo_dir=")) {
 294       dwo_dir = std::string(opt);
 295     } else if (opt.consume_front("opt-remarks-filename=")) {
 296       RemarksFilename = std::string(opt);
 297     } else if (opt.consume_front("opt-remarks-passes=")) {
 298       RemarksPasses = std::string(opt);
 299     } else if (opt == "opt-remarks-with-hotness") {
 300       RemarksWithHotness = true;
 301     } else if (opt.consume_front("opt-remarks-hotness-threshold=")) {
 302       auto ResultOrErr = remarks::parseHotnessThresholdOption(opt);
 303       if (!ResultOrErr)
 304         message(LDPL_FATAL, "Invalid remarks hotness threshold: %s", opt);
 305       else
 306         RemarksHotnessThreshold = *ResultOrErr;
 307     } else if (opt.consume_front("opt-remarks-format=")) {
 308       RemarksFormat = std::string(opt);
 309     } else if (opt.consume_front("stats-file=")) {
 310       stats_file = std::string(opt);
 311     } else {
 312       // Save this option to pass to the code generator.
 313       // ParseCommandLineOptions() expects argv[0] to be program name. Lazily
 314       // add that.
 315       if (extra.empty())
 316         extra.push_back("LLVMgold");
 317
 318       extra.push_back(opt_);
 319     }
 320   }
 321 }
 322
 323 static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
 324                                         int *claimed);
 325 static ld_plugin_status all_symbols_read_hook(void);
 326 static ld_plugin_status cleanup_hook(void);
 327
 328 extern "C" ld_plugin_status onload(ld_plugin_tv *tv);
 329 ld_plugin_status onload(ld_plugin_tv *tv) {
 330   InitializeAllTargetInfos();
 331   InitializeAllTargets();
 332   InitializeAllTargetMCs();
 333   InitializeAllAsmParsers();
 334   InitializeAllAsmPrinters();
 335
 336   // We're given a pointer to the first transfer vector. We read through them
 337   // until we find one where tv_tag == LDPT_NULL. The REGISTER_* tagged values
 338   // contain pointers to functions that we need to call to register our own
 339   // hooks. The others are addresses of functions we can use to call into gold
 340   // for services.
 341
 342   bool registeredClaimFile = false;
 343   bool RegisteredAllSymbolsRead = false;
 344
 345   for (; tv->tv_tag != LDPT_NULL; ++tv) {
 346     // Cast tv_tag to int to allow values not in "enum ld_plugin_tag", like, for
 347     // example, LDPT_GET_SYMBOLS_V3 when building against an older plugin-api.h
 348     // header.
 349     switch (static_cast<int>(tv->tv_tag)) {
 350     case LDPT_OUTPUT_NAME:
 351       output_name = tv->tv_u.tv_string;
 352       break;
 353     case LDPT_LINKER_OUTPUT:
 354       switch (tv->tv_u.tv_val) {
 355       case LDPO_REL: // .o
 356         IsExecutable = false;
 357         SplitSections = false;
 358         break;
 359       case LDPO_DYN: // .so
 360         IsExecutable = false;
 361         RelocationModel = Reloc::PIC_;
 362         break;
 363       case LDPO_PIE: // position independent executable
 364         IsExecutable = true;
 365         RelocationModel = Reloc::PIC_;
 366         break;
 367       case LDPO_EXEC: // .exe
 368         IsExecutable = true;
 369         RelocationModel = Reloc::Static;
 370         break;
 371       default:
 372         message(LDPL_ERROR, "Unknown output file type %d", tv->tv_u.tv_val);
 373         return LDPS_ERR;
 374       }
 375       break;
 376     case LDPT_OPTION:
 377       options::process_plugin_option(tv->tv_u.tv_string);
 378       break;
 379     case LDPT_REGISTER_CLAIM_FILE_HOOK: {
 380       ld_plugin_register_claim_file callback;
 381       callback = tv->tv_u.tv_register_claim_file;
 382
 383       if (callback(claim_file_hook) != LDPS_OK)
 384         return LDPS_ERR;
 385
 386       registeredClaimFile = true;
 387     } break;
 388     case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: {
 389       ld_plugin_register_all_symbols_read callback;
 390       callback = tv->tv_u.tv_register_all_symbols_read;
 391
 392       if (callback(all_symbols_read_hook) != LDPS_OK)
 393         return LDPS_ERR;
 394
 395       RegisteredAllSymbolsRead = true;
 396     } break;
 397     case LDPT_REGISTER_CLEANUP_HOOK: {
 398       ld_plugin_register_cleanup callback;
 399       callback = tv->tv_u.tv_register_cleanup;
 400
 401       if (callback(cleanup_hook) != LDPS_OK)
 402         return LDPS_ERR;
 403     } break;
 404     case LDPT_GET_INPUT_FILE:
 405       get_input_file = tv->tv_u.tv_get_input_file;
 406       break;
 407     case LDPT_RELEASE_INPUT_FILE:
 408       release_input_file = tv->tv_u.tv_release_input_file;
 409       break;
 410     case LDPT_ADD_SYMBOLS:
 411       add_symbols = tv->tv_u.tv_add_symbols;
 412       break;
 413     case LDPT_GET_SYMBOLS_V2:
 414       // Do not override get_symbols_v3 with get_symbols_v2.
 415       if (!get_symbols)
 416         get_symbols = tv->tv_u.tv_get_symbols;
 417       break;
 418     case LDPT_GET_SYMBOLS_V3:
 419       get_symbols = tv->tv_u.tv_get_symbols;
 420       break;
 421     case LDPT_ADD_INPUT_FILE:
 422       add_input_file = tv->tv_u.tv_add_input_file;
 423       break;
 424     case LDPT_SET_EXTRA_LIBRARY_PATH:
 425       set_extra_library_path = tv->tv_u.tv_set_extra_library_path;
 426       break;
 427     case LDPT_GET_VIEW:
 428       get_view = tv->tv_u.tv_get_view;
 429       break;
 430     case LDPT_MESSAGE:
 431       message = tv->tv_u.tv_message;
 432       break;
 433     case LDPT_GET_WRAP_SYMBOLS:
 434       // FIXME: When binutils 2.31 (containing gold 1.16) is the minimum
 435       // required version, this should be changed to:
 436       // get_wrap_symbols = tv->tv_u.tv_get_wrap_symbols;
 437       get_wrap_symbols =
 438           (ld_plugin_get_wrap_symbols)tv->tv_u.tv_message;
 439       break;
 440     default:
 441       break;
 442     }
 443   }
 444
 445   if (!registeredClaimFile) {
 446     message(LDPL_ERROR, "register_claim_file not passed to LLVMgold.");
 447     return LDPS_ERR;
 448   }
 449   if (!add_symbols) {
 450     message(LDPL_ERROR, "add_symbols not passed to LLVMgold.");
 451     return LDPS_ERR;
 452   }
 453
 454   if (!RegisteredAllSymbolsRead)
 455     return LDPS_OK;
 456
 457   if (!get_input_file) {
 458     message(LDPL_ERROR, "get_input_file not passed to LLVMgold.");
 459     return LDPS_ERR;
 460   }
 461   if (!release_input_file) {
 462     message(LDPL_ERROR, "release_input_file not passed to LLVMgold.");
 463     return LDPS_ERR;
 464   }
 465
 466   return LDPS_OK;
 467 }
 468
 469 static void diagnosticHandler(const DiagnosticInfo &DI) {
 470   std::string ErrStorage;
 471   {
 472     raw_string_ostream OS(ErrStorage);
 473     DiagnosticPrinterRawOStream DP(OS);
 474     DI.print(DP);
 475   }
 476   ld_plugin_level Level;
 477   switch (DI.getSeverity()) {
 478   case DS_Error:
 479     Level = LDPL_FATAL;
 480     break;
 481   case DS_Warning:
 482     Level = LDPL_WARNING;
 483     break;
 484   case DS_Note:
 485   case DS_Remark:
 486     Level = LDPL_INFO;
 487     break;
 488   }
 489   message(Level, "LLVM gold plugin: %s",  ErrStorage.c_str());
 490 }
 491
 492 static void check(Error E, std::string Msg = "LLVM gold plugin") {
 493   handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) -> Error {
 494     message(LDPL_FATAL, "%s: %s", Msg.c_str(), EIB.message().c_str());
 495     return Error::success();
 496   });
 497 }
 498
 499 template <typename T> static T check(Expected<T> E) {
 500   if (E)
 501     return std::move(*E);
 502   check(E.takeError());
 503   return T();
 504 }
 505
 506 /// Called by gold to see whether this file is one that our plugin can handle.
 507 /// We'll try to open it and register all the symbols with add_symbol if
 508 /// possible.
 509 static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
 510                                         int *claimed) {
 511   MemoryBufferRef BufferRef;
 512   std::unique_ptr<MemoryBuffer> Buffer;
 513   if (get_view) {
 514     const void *view;
 515     if (get_view(file->handle, &view) != LDPS_OK) {
 516       message(LDPL_ERROR, "Failed to get a view of %s", file->name);
 517       return LDPS_ERR;
 518     }
 519     BufferRef =
 520         MemoryBufferRef(StringRef((const char *)view, file->filesize), "");
 521   } else {
 522     int64_t offset = 0;
 523     // Gold has found what might be IR part-way inside of a file, such as
 524     // an .a archive.
 525     if (file->offset) {
 526       offset = file->offset;
 527     }
 528     ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
 529         MemoryBuffer::getOpenFileSlice(sys::fs::convertFDToNativeFile(file->fd),
 530                                        file->name, file->filesize, offset);
 531     if (std::error_code EC = BufferOrErr.getError()) {
 532       message(LDPL_ERROR, EC.message().c_str());
 533       return LDPS_ERR;
 534     }
 535     Buffer = std::move(BufferOrErr.get());
 536     BufferRef = Buffer->getMemBufferRef();
 537   }
 538
 539   *claimed = 1;
 540
 541   Expected<std::unique_ptr<InputFile>> ObjOrErr = InputFile::create(BufferRef);
 542   if (!ObjOrErr) {
 543     handleAllErrors(ObjOrErr.takeError(), [&](const ErrorInfoBase &EI) {
 544       std::error_code EC = EI.convertToErrorCode();
 545       if (EC == object::object_error::invalid_file_type ||
 546           EC == object::object_error::bitcode_section_not_found)
 547         *claimed = 0;
 548       else
 549         message(LDPL_FATAL,
 550                 "LLVM gold plugin has failed to create LTO module: %s",
 551                 EI.message().c_str());
 552     });
 553
 554     return *claimed ? LDPS_ERR : LDPS_OK;
 555   }
 556
 557   std::unique_ptr<InputFile> Obj = std::move(*ObjOrErr);
 558
 559   Modules.emplace_back();
 560   claimed_file &cf = Modules.back();
 561
 562   cf.handle = file->handle;
 563   // Keep track of the first handle for each file descriptor, since there are
 564   // multiple in the case of an archive. This is used later in the case of
 565   // ThinLTO parallel backends to ensure that each file is only opened and
 566   // released once.
 567   auto LeaderHandle =
 568       FDToLeaderHandle.insert(std::make_pair(file->fd, file->handle)).first;
 569   cf.leader_handle = LeaderHandle->second;
 570   // Save the filesize since for parallel ThinLTO backends we can only
 571   // invoke get_input_file once per archive (only for the leader handle).
 572   cf.filesize = file->filesize;
 573   // In the case of an archive library, all but the first member must have a
 574   // non-zero offset, which we can append to the file name to obtain a
 575   // unique name.
 576   cf.name = file->name;
 577   if (file->offset)
 578     cf.name += ".llvm." + std::to_string(file->offset) + "." +
 579                sys::path::filename(Obj->getSourceFileName()).str();
 580
 581   for (auto &Sym : Obj->symbols()) {
 582     cf.syms.push_back(ld_plugin_symbol());
 583     ld_plugin_symbol &sym = cf.syms.back();
 584     sym.version = nullptr;
 585     StringRef Name = Sym.getName();
 586     sym.name = strdup(Name.str().c_str());
 587
 588     ResolutionInfo &Res = ResInfo[Name];
 589
 590     Res.CanOmitFromDynSym &= Sym.canBeOmittedFromSymbolTable();
 591
 592     sym.visibility = LDPV_DEFAULT;
 593     GlobalValue::VisibilityTypes Vis = Sym.getVisibility();
 594     if (Vis != GlobalValue::DefaultVisibility)
 595       Res.DefaultVisibility = false;
 596     switch (Vis) {
 597     case GlobalValue::DefaultVisibility:
 598       break;
 599     case GlobalValue::HiddenVisibility:
 600       sym.visibility = LDPV_HIDDEN;
 601       break;
 602     case GlobalValue::ProtectedVisibility:
 603       sym.visibility = LDPV_PROTECTED;
 604       break;
 605     }
 606
 607     if (Sym.isUndefined()) {
 608       sym.def = LDPK_UNDEF;
 609       if (Sym.isWeak())
 610         sym.def = LDPK_WEAKUNDEF;
 611     } else if (Sym.isCommon())
 612       sym.def = LDPK_COMMON;
 613     else if (Sym.isWeak())
 614       sym.def = LDPK_WEAKDEF;
 615     else
 616       sym.def = LDPK_DEF;
 617
 618     sym.size = 0;
 619     sym.comdat_key = nullptr;
 620     int CI = Sym.getComdatIndex();
 621     if (CI != -1) {
 622       // Not setting comdat_key for nodeduplicate ensuress we don't deduplicate.
 623       std::pair<StringRef, Comdat::SelectionKind> C = Obj->getComdatTable()[CI];
 624       if (C.second != Comdat::NoDeduplicate)
 625         sym.comdat_key = strdup(C.first.str().c_str());
 626     }
 627
 628     sym.resolution = LDPR_UNKNOWN;
 629   }
 630
 631   if (!cf.syms.empty()) {
 632     if (add_symbols(cf.handle, cf.syms.size(), cf.syms.data()) != LDPS_OK) {
 633       message(LDPL_ERROR, "Unable to add symbols!");
 634       return LDPS_ERR;
 635     }
 636   }
 637
 638   // Handle any --wrap options passed to gold, which are than passed
 639   // along to the plugin.
 640   if (get_wrap_symbols) {
 641     const char **wrap_symbols;
 642     uint64_t count = 0;
 643     if (get_wrap_symbols(&count, &wrap_symbols) != LDPS_OK) {
 644       message(LDPL_ERROR, "Unable to get wrap symbols!");
 645       return LDPS_ERR;
 646     }
 647     for (uint64_t i = 0; i < count; i++) {
 648       StringRef Name = wrap_symbols[i];
 649       ResolutionInfo &Res = ResInfo[Name];
 650       ResolutionInfo &WrapRes = ResInfo["__wrap_" + Name.str()];
 651       ResolutionInfo &RealRes = ResInfo["__real_" + Name.str()];
 652       // Tell LTO not to inline symbols that will be overwritten.
 653       Res.CanInline = false;
 654       RealRes.CanInline = false;
 655       // Tell LTO not to eliminate symbols that will be used after renaming.
 656       Res.IsUsedInRegularObj = true;
 657       WrapRes.IsUsedInRegularObj = true;
 658     }
 659   }
 660
 661   return LDPS_OK;
 662 }
 663
 664 static void freeSymName(ld_plugin_symbol &Sym) {
 665   free(Sym.name);
 666   free(Sym.comdat_key);
 667   Sym.name = nullptr;
 668   Sym.comdat_key = nullptr;
 669 }
 670
 671 /// Helper to get a file's symbols and a view into it via gold callbacks.
 672 static const void *getSymbolsAndView(claimed_file &F) {
 673   ld_plugin_status status = get_symbols(F.handle, F.syms.size(), F.syms.data());
 674   if (status == LDPS_NO_SYMS)
 675     return nullptr;
 676
 677   if (status != LDPS_OK)
 678     message(LDPL_FATAL, "Failed to get symbol information");
 679
 680   const void *View;
 681   if (get_view(F.handle, &View) != LDPS_OK)
 682     message(LDPL_FATAL, "Failed to get a view of file");
 683
 684   return View;
 685 }
 686
 687 /// Parse the thinlto-object-suffix-replace option into the \p OldSuffix and
 688 /// \p NewSuffix strings, if it was specified.
 689 static void getThinLTOOldAndNewSuffix(std::string &OldSuffix,
 690                                       std::string &NewSuffix) {
 691   assert(options::thinlto_object_suffix_replace.empty() ||
 692          options::thinlto_object_suffix_replace.find(';') != StringRef::npos);
 693   StringRef SuffixReplace = options::thinlto_object_suffix_replace;
 694   auto Split = SuffixReplace.split(';');
 695   OldSuffix = std::string(Split.first);
 696   NewSuffix = std::string(Split.second);
 697 }
 698
 699 /// Given the original \p Path to an output file, replace any filename
 700 /// suffix matching \p OldSuffix with \p NewSuffix.
 701 static std::string getThinLTOObjectFileName(StringRef Path, StringRef OldSuffix,
 702                                             StringRef NewSuffix) {
 703   if (Path.consume_back(OldSuffix))
 704     return (Path + NewSuffix).str();
 705   return std::string(Path);
 706 }
 707
 708 // Returns true if S is valid as a C language identifier.
 709 static bool isValidCIdentifier(StringRef S) {
 710   return !S.empty() && (isAlpha(S[0]) || S[0] == '_') &&
 711          llvm::all_of(llvm::drop_begin(S),
 712                       [](char C) { return C == '_' || isAlnum(C); });
 713 }
 714
 715 static bool isUndefined(ld_plugin_symbol &Sym) {
 716   return Sym.def == LDPK_UNDEF || Sym.def == LDPK_WEAKUNDEF;
 717 }
 718
 719 static void addModule(LTO &Lto, claimed_file &F, const void *View,
 720                       StringRef Filename) {
 721   MemoryBufferRef BufferRef(StringRef((const char *)View, F.filesize),
 722                             Filename);
 723   Expected<std::unique_ptr<InputFile>> ObjOrErr = InputFile::create(BufferRef);
 724
 725   if (!ObjOrErr)
 726     message(LDPL_FATAL, "Could not read bitcode from file : %s",
 727             toString(ObjOrErr.takeError()).c_str());
 728
 729   unsigned SymNum = 0;
 730   std::unique_ptr<InputFile> Input = std::move(ObjOrErr.get());
 731   auto InputFileSyms = Input->symbols();
 732   assert(InputFileSyms.size() == F.syms.size());
 733   std::vector<SymbolResolution> Resols(F.syms.size());
 734   for (ld_plugin_symbol &Sym : F.syms) {
 735     const InputFile::Symbol &InpSym = InputFileSyms[SymNum];
 736     SymbolResolution &R = Resols[SymNum++];
 737
 738     ld_plugin_symbol_resolution Resolution =
 739         (ld_plugin_symbol_resolution)Sym.resolution;
 740
 741     ResolutionInfo &Res = ResInfo[Sym.name];
 742
 743     switch (Resolution) {
 744     case LDPR_UNKNOWN:
 745       llvm_unreachable("Unexpected resolution");
 746
 747     case LDPR_RESOLVED_IR:
 748     case LDPR_RESOLVED_EXEC:
 749     case LDPR_PREEMPTED_IR:
 750     case LDPR_PREEMPTED_REG:
 751     case LDPR_UNDEF:
 752       break;
 753
 754     case LDPR_RESOLVED_DYN:
 755       R.ExportDynamic = true;
 756       break;
 757
 758     case LDPR_PREVAILING_DEF_IRONLY:
 759       R.Prevailing = !isUndefined(Sym);
 760       break;
 761
 762     case LDPR_PREVAILING_DEF:
 763       R.Prevailing = !isUndefined(Sym);
 764       R.VisibleToRegularObj = true;
 765       break;
 766
 767     case LDPR_PREVAILING_DEF_IRONLY_EXP:
 768       R.Prevailing = !isUndefined(Sym);
 769       // Identify symbols exported dynamically, and that therefore could be
 770       // referenced by a shared library not visible to the linker.
 771       R.ExportDynamic = true;
 772       if (!Res.CanOmitFromDynSym)
 773         R.VisibleToRegularObj = true;
 774       break;
 775     }
 776
 777     // If the symbol has a C identifier section name, we need to mark
 778     // it as visible to a regular object so that LTO will keep it around
 779     // to ensure the linker generates special __start_<secname> and
 780     // __stop_<secname> symbols which may be used elsewhere.
 781     if (isValidCIdentifier(InpSym.getSectionName()))
 782       R.VisibleToRegularObj = true;
 783
 784     if (Resolution != LDPR_RESOLVED_DYN && Resolution != LDPR_UNDEF &&
 785         (IsExecutable || !Res.DefaultVisibility))
 786       R.FinalDefinitionInLinkageUnit = true;
 787
 788     if (!Res.CanInline)
 789       R.LinkerRedefined = true;
 790
 791     if (Res.IsUsedInRegularObj)
 792       R.VisibleToRegularObj = true;
 793
 794     freeSymName(Sym);
 795   }
 796
 797   check(Lto.add(std::move(Input), Resols),
 798         std::string("Failed to link module ") + F.name);
 799 }
 800
 801 static void recordFile(const std::string &Filename, bool TempOutFile) {
 802   if (add_input_file(Filename.c_str()) != LDPS_OK)
 803     message(LDPL_FATAL,
 804             "Unable to add .o file to the link. File left behind in: %s",
 805             Filename.c_str());
 806   if (TempOutFile)
 807     Cleanup.push_back(Filename);
 808 }
 809
 810 /// Return the desired output filename given a base input name, a flag
 811 /// indicating whether a temp file should be generated, and an optional task id.
 812 /// The new filename generated is returned in \p NewFilename.
 813 static int getOutputFileName(StringRef InFilename, bool TempOutFile,
 814                              SmallString<128> &NewFilename, int TaskID) {
 815   int FD = -1;
 816   if (TempOutFile) {
 817     std::error_code EC =
 818         sys::fs::createTemporaryFile("lto-llvm", "o", FD, NewFilename);
 819     if (EC)
 820       message(LDPL_FATAL, "Could not create temporary file: %s",
 821               EC.message().c_str());
 822   } else {
 823     NewFilename = InFilename;
 824     if (TaskID > 0)
 825       NewFilename += utostr(TaskID);
 826     std::error_code EC =
 827         sys::fs::openFileForWrite(NewFilename, FD, sys::fs::CD_CreateAlways);
 828     if (EC)
 829       message(LDPL_FATAL, "Could not open file %s: %s", NewFilename.c_str(),
 830               EC.message().c_str());
 831   }
 832   return FD;
 833 }
 834
 835 /// Parse the thinlto_prefix_replace option into the \p OldPrefix and
 836 /// \p NewPrefix strings, if it was specified.
 837 static void getThinLTOOldAndNewPrefix(std::string &OldPrefix,
 838                                       std::string &NewPrefix) {
 839   StringRef PrefixReplace = options::thinlto_prefix_replace;
 840   assert(PrefixReplace.empty() || PrefixReplace.find(';') != StringRef::npos);
 841   auto Split = PrefixReplace.split(';');
 842   OldPrefix = std::string(Split.first);
 843   NewPrefix = std::string(Split.second);
 844 }
 845
 846 /// Creates instance of LTO.
 847 /// OnIndexWrite is callback to let caller know when LTO writes index files.
 848 /// LinkedObjectsFile is an output stream to write the list of object files for
 849 /// the final ThinLTO linking. Can be nullptr.
 850 static std::unique_ptr<LTO> createLTO(IndexWriteCallback OnIndexWrite,
 851                                       raw_fd_ostream *LinkedObjectsFile) {
 852   Config Conf;
 853   ThinBackend Backend;
 854
 855   Conf.CPU = options::mcpu;
 856   Conf.Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple());
 857
 858   // Disable the new X86 relax relocations since gold might not support them.
 859   // FIXME: Check the gold version or add a new option to enable them.
 860   Conf.Options.RelaxELFRelocations = false;
 861
 862   // Toggle function/data sections.
 863   if (!codegen::getExplicitFunctionSections())
 864     Conf.Options.FunctionSections = SplitSections;
 865   if (!codegen::getExplicitDataSections())
 866     Conf.Options.DataSections = SplitSections;
 867
 868   Conf.MAttrs = codegen::getMAttrs();
 869   Conf.RelocModel = RelocationModel;
 870   Conf.CodeModel = codegen::getExplicitCodeModel();
 871   std::optional<CodeGenOptLevel> CGOptLevelOrNone =
 872       CodeGenOpt::getLevel(options::OptLevel);
 873   assert(CGOptLevelOrNone && "Invalid optimization level");
 874   Conf.CGOptLevel = *CGOptLevelOrNone;
 875   Conf.DisableVerify = options::DisableVerify;
 876   Conf.OptLevel = options::OptLevel;
 877   Conf.PTO.LoopVectorization = options::OptLevel > 1;
 878   Conf.PTO.SLPVectorization = options::OptLevel > 1;
 879   Conf.AlwaysEmitRegularLTOObj = !options::obj_path.empty();
 880
 881   if (options::thinlto_index_only) {
 882     std::string OldPrefix, NewPrefix;
 883     getThinLTOOldAndNewPrefix(OldPrefix, NewPrefix);
 884     Backend = createWriteIndexesThinBackend(
 885         OldPrefix, NewPrefix,
 886         // TODO: Add support for optional native object path in
 887         // thinlto_prefix_replace option to match lld.
 888         /*NativeObjectPrefix=*/"", options::thinlto_emit_imports_files,
 889         LinkedObjectsFile, OnIndexWrite);
 890   } else {
 891     Backend = createInProcessThinBackend(
 892         llvm::heavyweight_hardware_concurrency(options::Parallelism));
 893   }
 894
 895   Conf.OverrideTriple = options::triple;
 896   Conf.DefaultTriple = sys::getDefaultTargetTriple();
 897
 898   Conf.DiagHandler = diagnosticHandler;
 899
 900   switch (options::TheOutputType) {
 901   case options::OT_NORMAL:
 902     break;
 903
 904   case options::OT_DISABLE:
 905     Conf.PreOptModuleHook = [](size_t Task, const Module &M) { return false; };
 906     break;
 907
 908   case options::OT_BC_ONLY:
 909     Conf.PostInternalizeModuleHook = [](size_t Task, const Module &M) {
 910       std::error_code EC;
 911       SmallString<128> TaskFilename;
 912       getOutputFileName(output_name, /* TempOutFile */ false, TaskFilename,
 913                         Task);
 914       raw_fd_ostream OS(TaskFilename, EC, sys::fs::OpenFlags::OF_None);
 915       if (EC)
 916         message(LDPL_FATAL, "Failed to write the output file.");
 917       WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ false);
 918       return false;
 919     };
 920     break;
 921
 922   case options::OT_SAVE_TEMPS:
 923     check(Conf.addSaveTemps(output_name + ".",
 924                             /* UseInputModulePath */ true));
 925     break;
 926   case options::OT_ASM_ONLY:
 927     Conf.CGFileType = CodeGenFileType::AssemblyFile;
 928     break;
 929   }
 930
 931   if (!options::sample_profile.empty())
 932     Conf.SampleProfile = options::sample_profile;
 933
 934   if (!options::cs_profile_path.empty())
 935     Conf.CSIRProfile = options::cs_profile_path;
 936   Conf.RunCSIRInstr = options::cs_pgo_gen;
 937
 938   Conf.DwoDir = options::dwo_dir;
 939
 940   // Set up optimization remarks handling.
 941   Conf.RemarksFilename = options::RemarksFilename;
 942   Conf.RemarksPasses = options::RemarksPasses;
 943   Conf.RemarksWithHotness = options::RemarksWithHotness;
 944   Conf.RemarksHotnessThreshold = options::RemarksHotnessThreshold;
 945   Conf.RemarksFormat = options::RemarksFormat;
 946
 947   // Debug new pass manager if requested
 948   Conf.DebugPassManager = options::debug_pass_manager;
 949
 950   Conf.HasWholeProgramVisibility = options::whole_program_visibility;
 951
 952   Conf.StatsFile = options::stats_file;
 953   return std::make_unique<LTO>(std::move(Conf), Backend,
 954                                 options::ParallelCodeGenParallelismLevel);
 955 }
 956
 957 // Write empty files that may be expected by a distributed build
 958 // system when invoked with thinlto_index_only. This is invoked when
 959 // the linker has decided not to include the given module in the
 960 // final link. Frequently the distributed build system will want to
 961 // confirm that all expected outputs are created based on all of the
 962 // modules provided to the linker.
 963 // If SkipModule is true then .thinlto.bc should contain just
 964 // SkipModuleByDistributedBackend flag which requests distributed backend
 965 // to skip the compilation of the corresponding module and produce an empty
 966 // object file.
 967 static void writeEmptyDistributedBuildOutputs(const std::string &ModulePath,
 968                                               const std::string &OldPrefix,
 969                                               const std::string &NewPrefix,
 970                                               bool SkipModule) {
 971   std::string NewModulePath =
 972       getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix);
 973   std::error_code EC;
 974   {
 975     raw_fd_ostream OS(NewModulePath + ".thinlto.bc", EC,
 976                       sys::fs::OpenFlags::OF_None);
 977     if (EC)
 978       message(LDPL_FATAL, "Failed to write '%s': %s",
 979               (NewModulePath + ".thinlto.bc").c_str(), EC.message().c_str());
 980
 981     if (SkipModule) {
 982       ModuleSummaryIndex Index(/*HaveGVs*/ false);
 983       Index.setSkipModuleByDistributedBackend();
 984       writeIndexToFile(Index, OS, nullptr);
 985     }
 986   }
 987   if (options::thinlto_emit_imports_files) {
 988     raw_fd_ostream OS(NewModulePath + ".imports", EC,
 989                       sys::fs::OpenFlags::OF_None);
 990     if (EC)
 991       message(LDPL_FATAL, "Failed to write '%s': %s",
 992               (NewModulePath + ".imports").c_str(), EC.message().c_str());
 993   }
 994 }
 995
 996 // Creates and returns output stream with a list of object files for final
 997 // linking of distributed ThinLTO.
 998 static std::unique_ptr<raw_fd_ostream> CreateLinkedObjectsFile() {
 999   if (options::thinlto_linked_objects_file.empty())
1000     return nullptr;
1001   assert(options::thinlto_index_only);
1002   std::error_code EC;
1003   auto LinkedObjectsFile = std::make_unique<raw_fd_ostream>(
1004       options::thinlto_linked_objects_file, EC, sys::fs::OpenFlags::OF_None);
1005   if (EC)
1006     message(LDPL_FATAL, "Failed to create '%s': %s",
1007             options::thinlto_linked_objects_file.c_str(), EC.message().c_str());
1008   return LinkedObjectsFile;
1009 }
1010
1011 /// Runs LTO and return a list of pairs <FileName, IsTemporary>.
1012 static std::vector<std::pair<SmallString<128>, bool>> runLTO() {
1013   // Map to own RAII objects that manage the file opening and releasing
1014   // interfaces with gold. This is needed only for ThinLTO mode, since
1015   // unlike regular LTO, where addModule will result in the opened file
1016   // being merged into a new combined module, we need to keep these files open
1017   // through Lto->run().
1018   DenseMap<void *, std::unique_ptr<PluginInputFile>> HandleToInputFile;
1019
1020   // Owns string objects and tells if index file was already created.
1021   StringMap<bool> ObjectToIndexFileState;
1022
1023   std::unique_ptr<raw_fd_ostream> LinkedObjects = CreateLinkedObjectsFile();
1024   std::unique_ptr<LTO> Lto = createLTO(
1025       [&ObjectToIndexFileState](const std::string &Identifier) {
1026         ObjectToIndexFileState[Identifier] = true;
1027       },
1028       LinkedObjects.get());
1029
1030   std::string OldPrefix, NewPrefix;
1031   if (options::thinlto_index_only)
1032     getThinLTOOldAndNewPrefix(OldPrefix, NewPrefix);
1033
1034   std::string OldSuffix, NewSuffix;
1035   getThinLTOOldAndNewSuffix(OldSuffix, NewSuffix);
1036
1037   for (claimed_file &F : Modules) {
1038     if (options::thinlto && !HandleToInputFile.count(F.leader_handle))
1039       HandleToInputFile.insert(std::make_pair(
1040           F.leader_handle, std::make_unique<PluginInputFile>(F.handle)));
1041     // In case we are thin linking with a minimized bitcode file, ensure
1042     // the module paths encoded in the index reflect where the backends
1043     // will locate the full bitcode files for compiling/importing.
1044     std::string Identifier =
1045         getThinLTOObjectFileName(F.name, OldSuffix, NewSuffix);
1046     auto ObjFilename = ObjectToIndexFileState.insert({Identifier, false});
1047     assert(ObjFilename.second);
1048     if (const void *View = getSymbolsAndView(F))
1049       addModule(*Lto, F, View, ObjFilename.first->first());
1050     else if (options::thinlto_index_only) {
1051       ObjFilename.first->second = true;
1052       writeEmptyDistributedBuildOutputs(Identifier, OldPrefix, NewPrefix,
1053                                         /* SkipModule */ true);
1054     }
1055   }
1056
1057   SmallString<128> Filename;
1058   // Note that getOutputFileName will append a unique ID for each task
1059   if (!options::obj_path.empty())
1060     Filename = options::obj_path;
1061   else if (options::TheOutputType == options::OT_SAVE_TEMPS)
1062     Filename = output_name + ".lto.o";
1063   else if (options::TheOutputType == options::OT_ASM_ONLY)
1064     Filename = output_name;
1065   bool SaveTemps = !Filename.empty();
1066
1067   size_t MaxTasks = Lto->getMaxTasks();
1068   std::vector<std::pair<SmallString<128>, bool>> Files(MaxTasks);
1069
1070   auto AddStream =
1071       [&](size_t Task,
1072           const Twine &ModuleName) -> std::unique_ptr<CachedFileStream> {
1073     Files[Task].second = !SaveTemps;
1074     int FD = getOutputFileName(Filename, /* TempOutFile */ !SaveTemps,
1075                                Files[Task].first, Task);
1076     return std::make_unique<CachedFileStream>(
1077         std::make_unique<llvm::raw_fd_ostream>(FD, true));
1078   };
1079
1080   auto AddBuffer = [&](size_t Task, const Twine &moduleName,
1081                        std::unique_ptr<MemoryBuffer> MB) {
1082     *AddStream(Task, moduleName)->OS << MB->getBuffer();
1083   };
1084
1085   FileCache Cache;
1086   if (!options::cache_dir.empty())
1087     Cache = check(localCache("ThinLTO", "Thin", options::cache_dir, AddBuffer));
1088
1089   check(Lto->run(AddStream, Cache));
1090
1091   // Write empty output files that may be expected by the distributed build
1092   // system.
1093   if (options::thinlto_index_only)
1094     for (auto &Identifier : ObjectToIndexFileState)
1095       if (!Identifier.getValue())
1096         writeEmptyDistributedBuildOutputs(std::string(Identifier.getKey()),
1097                                           OldPrefix, NewPrefix,
1098                                           /* SkipModule */ false);
1099
1100   return Files;
1101 }
1102
1103 /// gold informs us that all symbols have been read. At this point, we use
1104 /// get_symbols to see if any of our definitions have been overridden by a
1105 /// native object file. Then, perform optimization and codegen.
1106 static ld_plugin_status allSymbolsReadHook() {
1107   if (Modules.empty())
1108     return LDPS_OK;
1109
1110   if (unsigned NumOpts = options::extra.size())
1111     cl::ParseCommandLineOptions(NumOpts, &options::extra[0]);
1112
1113   std::vector<std::pair<SmallString<128>, bool>> Files = runLTO();
1114
1115   if (options::TheOutputType == options::OT_DISABLE ||
1116       options::TheOutputType == options::OT_BC_ONLY ||
1117       options::TheOutputType == options::OT_ASM_ONLY)
1118     return LDPS_OK;
1119
1120   if (options::thinlto_index_only) {
1121     llvm_shutdown();
1122     cleanup_hook();
1123     exit(0);
1124   }
1125
1126   for (const auto &F : Files)
1127     if (!F.first.empty())
1128       recordFile(std::string(F.first.str()), F.second);
1129
1130   if (!options::extra_library_path.empty() &&
1131       set_extra_library_path(options::extra_library_path.c_str()) != LDPS_OK)
1132     message(LDPL_FATAL, "Unable to set the extra library path.");
1133
1134   return LDPS_OK;
1135 }
1136
1137 static ld_plugin_status all_symbols_read_hook(void) {
1138   ld_plugin_status Ret = allSymbolsReadHook();
1139   llvm_shutdown();
1140
1141   if (options::TheOutputType == options::OT_BC_ONLY ||
1142       options::TheOutputType == options::OT_ASM_ONLY ||
1143       options::TheOutputType == options::OT_DISABLE) {
1144     if (options::TheOutputType == options::OT_DISABLE) {
1145       // Remove the output file here since ld.bfd creates the output file
1146       // early.
1147       std::error_code EC = sys::fs::remove(output_name);
1148       if (EC)
1149         message(LDPL_ERROR, "Failed to delete '%s': %s", output_name.c_str(),
1150                 EC.message().c_str());
1151     }
1152     exit(0);
1153   }
1154
1155   return Ret;
1156 }
1157
1158 static ld_plugin_status cleanup_hook(void) {
1159   for (std::string &Name : Cleanup) {
1160     std::error_code EC = sys::fs::remove(Name);
1161     if (EC)
1162       message(LDPL_ERROR, "Failed to delete '%s': %s", Name.c_str(),
1163               EC.message().c_str());
1164   }
1165
1166   // Prune cache
1167   if (!options::cache_dir.empty()) {
1168     CachePruningPolicy policy = check(parseCachePruningPolicy(options::cache_policy));
1169     pruneCache(options::cache_dir, policy);
1170   }
1171
1172   return LDPS_OK;
1173 }