1//===- opt.cpp - The LLVM Modular Optimizer -------------------------------===//
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// Optimizations may be specified an arbitrary number of times on the command
10// line, They are run in the order specified.
11//
12//===----------------------------------------------------------------------===//
13
14#include "NewPMDriver.h"
15#include "llvm/Analysis/CallGraph.h"
16#include "llvm/Analysis/CallGraphSCCPass.h"
17#include "llvm/Analysis/LoopPass.h"
18#include "llvm/Analysis/RegionPass.h"
19#include "llvm/Analysis/TargetLibraryInfo.h"
20#include "llvm/Analysis/TargetTransformInfo.h"
21#include "llvm/AsmParser/Parser.h"
22#include "llvm/CodeGen/CommandFlags.h"
23#include "llvm/CodeGen/TargetPassConfig.h"
24#include "llvm/Config/llvm-config.h"
25#include "llvm/IR/DataLayout.h"
26#include "llvm/IR/DebugInfo.h"
27#include "llvm/IR/LLVMContext.h"
28#include "llvm/IR/LLVMRemarkStreamer.h"
29#include "llvm/IR/LegacyPassManager.h"
30#include "llvm/IR/LegacyPassNameParser.h"
31#include "llvm/IR/Module.h"
32#include "llvm/IR/ModuleSummaryIndex.h"
33#include "llvm/IR/Verifier.h"
34#include "llvm/IRReader/IRReader.h"
35#include "llvm/InitializePasses.h"
36#include "llvm/LinkAllIR.h"
37#include "llvm/LinkAllPasses.h"
38#include "llvm/MC/TargetRegistry.h"
39#include "llvm/Passes/PassPlugin.h"
40#include "llvm/Remarks/HotnessThresholdParser.h"
41#include "llvm/Support/Debug.h"
42#include "llvm/Support/ErrorHandling.h"
43#include "llvm/Support/FileSystem.h"
44#include "llvm/Support/InitLLVM.h"
45#include "llvm/Support/PluginLoader.h"
46#include "llvm/Support/SourceMgr.h"
47#include "llvm/Support/SystemUtils.h"
48#include "llvm/Support/TargetSelect.h"
49#include "llvm/Support/ToolOutputFile.h"
50#include "llvm/Support/YAMLTraits.h"
51#include "llvm/Target/TargetMachine.h"
52#include "llvm/TargetParser/Host.h"
53#include "llvm/TargetParser/SubtargetFeature.h"
54#include "llvm/TargetParser/Triple.h"
55#include "llvm/Transforms/IPO/WholeProgramDevirt.h"
56#include "llvm/Transforms/Utils/Cloning.h"
57#include "llvm/Transforms/Utils/Debugify.h"
58#include <algorithm>
59#include <memory>
60#include <optional>
61using namespace llvm;
62using namespace opt_tool;
63
64static codegen::RegisterCodeGenFlags CFG;
65
66// The OptimizationList is automatically populated with registered Passes by the
67// PassNameParser.
68static cl::list<const PassInfo *, bool, PassNameParser> PassList(cl::desc(
69    "Optimizations available (use '-passes=' for the new pass manager)"));
70
71static cl::opt<bool> EnableLegacyPassManager(
72    "bugpoint-enable-legacy-pm",
73    cl::desc(
74        "Enable the legacy pass manager. This is strictly for bugpoint "
75        "due to it not working with the new PM, please do not use otherwise."),
76    cl::init(false));
77
78// This flag specifies a textual description of the optimization pass pipeline
79// to run over the module. This flag switches opt to use the new pass manager
80// infrastructure, completely disabling all of the flags specific to the old
81// pass management.
82static cl::opt<std::string> PassPipeline(
83    "passes",
84    cl::desc(
85        "A textual description of the pass pipeline. To have analysis passes "
86        "available before a certain pass, add 'require<foo-analysis>'."));
87static cl::alias PassPipeline2("p", cl::aliasopt(PassPipeline),
88                                   cl::desc("Alias for -passes"));
89
90static cl::opt<bool> PrintPasses("print-passes",
91                                 cl::desc("Print available passes that can be "
92                                          "specified in -passes=foo and exit"));
93
94static cl::opt<std::string>
95InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
96    cl::init("-"), cl::value_desc("filename"));
97
98static cl::opt<std::string>
99OutputFilename("o", cl::desc("Override output filename"),
100               cl::value_desc("filename"));
101
102static cl::opt<bool>
103Force("f", cl::desc("Enable binary output on terminals"));
104
105static cl::opt<bool>
106NoOutput("disable-output",
107         cl::desc("Do not write result bitcode file"), cl::Hidden);
108
109static cl::opt<bool>
110OutputAssembly("S", cl::desc("Write output as LLVM assembly"));
111
112static cl::opt<bool>
113    OutputThinLTOBC("thinlto-bc",
114                    cl::desc("Write output as ThinLTO-ready bitcode"));
115
116static cl::opt<bool>
117    SplitLTOUnit("thinlto-split-lto-unit",
118                 cl::desc("Enable splitting of a ThinLTO LTOUnit"));
119
120static cl::opt<bool>
121    UnifiedLTO("unified-lto",
122               cl::desc("Use unified LTO piplines. Ignored unless -thinlto-bc "
123                        "is also specified."),
124               cl::Hidden, cl::init(false));
125
126static cl::opt<std::string> ThinLinkBitcodeFile(
127    "thin-link-bitcode-file", cl::value_desc("filename"),
128    cl::desc(
129        "A file in which to write minimized bitcode for the thin link only"));
130
131static cl::opt<bool>
132NoVerify("disable-verify", cl::desc("Do not run the verifier"), cl::Hidden);
133
134static cl::opt<bool> NoUpgradeDebugInfo("disable-upgrade-debug-info",
135                                        cl::desc("Generate invalid output"),
136                                        cl::ReallyHidden);
137
138static cl::opt<bool> VerifyEach("verify-each",
139                                cl::desc("Verify after each transform"));
140
141static cl::opt<bool>
142    DisableDITypeMap("disable-debug-info-type-map",
143                     cl::desc("Don't use a uniquing type map for debug info"));
144
145static cl::opt<bool>
146StripDebug("strip-debug",
147           cl::desc("Strip debugger symbol info from translation unit"));
148
149static cl::opt<bool>
150    StripNamedMetadata("strip-named-metadata",
151                       cl::desc("Strip module-level named metadata"));
152
153static cl::opt<bool>
154    OptLevelO0("O0", cl::desc("Optimization level 0. Similar to clang -O0. "
155                              "Same as -passes='default<O0>'"));
156
157static cl::opt<bool>
158    OptLevelO1("O1", cl::desc("Optimization level 1. Similar to clang -O1. "
159                              "Same as -passes='default<O1>'"));
160
161static cl::opt<bool>
162    OptLevelO2("O2", cl::desc("Optimization level 2. Similar to clang -O2. "
163                              "Same as -passes='default<O2>'"));
164
165static cl::opt<bool>
166    OptLevelOs("Os", cl::desc("Like -O2 but size-conscious. Similar to clang "
167                              "-Os. Same as -passes='default<Os>'"));
168
169static cl::opt<bool> OptLevelOz(
170    "Oz",
171    cl::desc("Like -O2 but optimize for code size above all else. Similar to "
172             "clang -Oz. Same as -passes='default<Oz>'"));
173
174static cl::opt<bool>
175    OptLevelO3("O3", cl::desc("Optimization level 3. Similar to clang -O3. "
176                              "Same as -passes='default<O3>'"));
177
178static cl::opt<unsigned> CodeGenOptLevelCL(
179    "codegen-opt-level",
180    cl::desc("Override optimization level for codegen hooks, legacy PM only"));
181
182static cl::opt<std::string>
183TargetTriple("mtriple", cl::desc("Override target triple for module"));
184
185static cl::opt<bool> EmitSummaryIndex("module-summary",
186                                      cl::desc("Emit module summary index"),
187                                      cl::init(false));
188
189static cl::opt<bool> EmitModuleHash("module-hash", cl::desc("Emit module hash"),
190                                    cl::init(false));
191
192static cl::opt<bool>
193DisableSimplifyLibCalls("disable-simplify-libcalls",
194                        cl::desc("Disable simplify-libcalls"));
195
196static cl::list<std::string> DisableBuiltins(
197    "disable-builtin",
198    cl::desc("Disable specific target library builtin function"));
199
200static cl::opt<bool> EnableDebugify(
201    "enable-debugify",
202    cl::desc(
203        "Start the pipeline with debugify and end it with check-debugify"));
204
205static cl::opt<bool> VerifyDebugInfoPreserve(
206    "verify-debuginfo-preserve",
207    cl::desc("Start the pipeline with collecting and end it with checking of "
208             "debug info preservation."));
209
210static cl::opt<std::string> ClDataLayout("data-layout",
211                                         cl::desc("data layout string to use"),
212                                         cl::value_desc("layout-string"),
213                                         cl::init(""));
214
215static cl::opt<bool> PreserveBitcodeUseListOrder(
216    "preserve-bc-uselistorder",
217    cl::desc("Preserve use-list order when writing LLVM bitcode."),
218    cl::init(true), cl::Hidden);
219
220static cl::opt<bool> PreserveAssemblyUseListOrder(
221    "preserve-ll-uselistorder",
222    cl::desc("Preserve use-list order when writing LLVM assembly."),
223    cl::init(false), cl::Hidden);
224
225static cl::opt<bool> RunTwice("run-twice",
226                              cl::desc("Run all passes twice, re-using the "
227                                       "same pass manager (legacy PM only)."),
228                              cl::init(false), cl::Hidden);
229
230static cl::opt<bool> DiscardValueNames(
231    "discard-value-names",
232    cl::desc("Discard names from Value (other than GlobalValue)."),
233    cl::init(false), cl::Hidden);
234
235static cl::opt<bool> TimeTrace(
236    "time-trace",
237    cl::desc("Record time trace"));
238
239static cl::opt<unsigned> TimeTraceGranularity(
240    "time-trace-granularity",
241    cl::desc("Minimum time granularity (in microseconds) traced by time profiler"),
242    cl::init(500), cl::Hidden);
243
244static cl::opt<std::string>
245    TimeTraceFile("time-trace-file",
246                    cl::desc("Specify time trace file destination"),
247                    cl::value_desc("filename"));
248
249static cl::opt<bool> RemarksWithHotness(
250    "pass-remarks-with-hotness",
251    cl::desc("With PGO, include profile count in optimization remarks"),
252    cl::Hidden);
253
254static cl::opt<std::optional<uint64_t>, false, remarks::HotnessThresholdParser>
255    RemarksHotnessThreshold(
256        "pass-remarks-hotness-threshold",
257        cl::desc("Minimum profile count required for "
258                 "an optimization remark to be output. "
259                 "Use 'auto' to apply the threshold from profile summary"),
260        cl::value_desc("N or 'auto'"), cl::init(0), cl::Hidden);
261
262static cl::opt<std::string>
263    RemarksFilename("pass-remarks-output",
264                    cl::desc("Output filename for pass remarks"),
265                    cl::value_desc("filename"));
266
267static cl::opt<std::string>
268    RemarksPasses("pass-remarks-filter",
269                  cl::desc("Only record optimization remarks from passes whose "
270                           "names match the given regular expression"),
271                  cl::value_desc("regex"));
272
273static cl::opt<std::string> RemarksFormat(
274    "pass-remarks-format",
275    cl::desc("The format used for serializing remarks (default: YAML)"),
276    cl::value_desc("format"), cl::init("yaml"));
277
278static cl::list<std::string>
279    PassPlugins("load-pass-plugin",
280                cl::desc("Load passes from plugin library"));
281
282static cl::opt<bool> TryUseNewDbgInfoFormat(
283    "try-experimental-debuginfo-iterators",
284    cl::desc("Enable debuginfo iterator positions, if they're built in"),
285    cl::init(false), cl::Hidden);
286
287extern cl::opt<bool> UseNewDbgInfoFormat;
288
289//===----------------------------------------------------------------------===//
290// CodeGen-related helper functions.
291//
292
293static CodeGenOptLevel GetCodeGenOptLevel() {
294  return static_cast<CodeGenOptLevel>(unsigned(CodeGenOptLevelCL));
295}
296
297struct TimeTracerRAII {
298  TimeTracerRAII(StringRef ProgramName) {
299    if (TimeTrace)
300      timeTraceProfilerInitialize(TimeTraceGranularity, ProgramName);
301  }
302  ~TimeTracerRAII() {
303    if (TimeTrace) {
304      if (auto E = timeTraceProfilerWrite(TimeTraceFile, OutputFilename)) {
305        handleAllErrors(std::move(E), [&](const StringError &SE) {
306          errs() << SE.getMessage() << "\n";
307        });
308        return;
309      }
310      timeTraceProfilerCleanup();
311    }
312  }
313};
314
315// For use in NPM transition. Currently this contains most codegen-specific
316// passes. Remove passes from here when porting to the NPM.
317// TODO: use a codegen version of PassRegistry.def/PassBuilder::is*Pass() once
318// it exists.
319static bool shouldPinPassToLegacyPM(StringRef Pass) {
320  std::vector<StringRef> PassNameExactToIgnore = {
321      "nvvm-reflect",
322      "nvvm-intr-range",
323      "amdgpu-simplifylib",
324      "amdgpu-image-intrinsic-opt",
325      "amdgpu-usenative",
326      "amdgpu-promote-alloca",
327      "amdgpu-promote-alloca-to-vector",
328      "amdgpu-lower-kernel-attributes",
329      "amdgpu-propagate-attributes-early",
330      "amdgpu-propagate-attributes-late",
331      "amdgpu-unify-metadata",
332      "amdgpu-printf-runtime-binding",
333      "amdgpu-always-inline"};
334  if (llvm::is_contained(PassNameExactToIgnore, Pass))
335    return false;
336
337  std::vector<StringRef> PassNamePrefix = {
338      "x86-",    "xcore-", "wasm-",  "systemz-", "ppc-",    "nvvm-",
339      "nvptx-",  "mips-",  "lanai-", "hexagon-", "bpf-",    "avr-",
340      "thumb2-", "arm-",   "si-",    "gcn-",     "amdgpu-", "aarch64-",
341      "amdgcn-", "polly-", "riscv-", "dxil-"};
342  std::vector<StringRef> PassNameContain = {"-eh-prepare"};
343  std::vector<StringRef> PassNameExact = {
344      "safe-stack",
345      "cost-model",
346      "codegenprepare",
347      "interleaved-load-combine",
348      "unreachableblockelim",
349      "verify-safepoint-ir",
350      "atomic-expand",
351      "expandvp",
352      "mve-tail-predication",
353      "interleaved-access",
354      "global-merge",
355      "pre-isel-intrinsic-lowering",
356      "expand-reductions",
357      "indirectbr-expand",
358      "generic-to-nvvm",
359      "expand-memcmp",
360      "loop-reduce",
361      "lower-amx-type",
362      "lower-amx-intrinsics",
363      "polyhedral-info",
364      "print-polyhedral-info",
365      "replace-with-veclib",
366      "jmc-instrumenter",
367      "dot-regions",
368      "dot-regions-only",
369      "view-regions",
370      "view-regions-only",
371      "select-optimize",
372      "expand-large-div-rem",
373      "structurizecfg",
374      "fix-irreducible",
375      "expand-large-fp-convert",
376      "callbrprepare",
377  };
378  for (const auto &P : PassNamePrefix)
379    if (Pass.starts_with(P))
380      return true;
381  for (const auto &P : PassNameContain)
382    if (Pass.contains(P))
383      return true;
384  return llvm::is_contained(PassNameExact, Pass);
385}
386
387// For use in NPM transition.
388static bool shouldForceLegacyPM() {
389  for (const auto &P : PassList) {
390    StringRef Arg = P->getPassArgument();
391    if (shouldPinPassToLegacyPM(Arg))
392      return true;
393  }
394  return false;
395}
396
397//===----------------------------------------------------------------------===//
398// main for opt
399//
400int main(int argc, char **argv) {
401  InitLLVM X(argc, argv);
402
403  // Enable debug stream buffering.
404  EnableDebugBuffering = true;
405
406  InitializeAllTargets();
407  InitializeAllTargetMCs();
408  InitializeAllAsmPrinters();
409  InitializeAllAsmParsers();
410
411  // Initialize passes
412  PassRegistry &Registry = *PassRegistry::getPassRegistry();
413  initializeCore(Registry);
414  initializeScalarOpts(Registry);
415  initializeVectorization(Registry);
416  initializeIPO(Registry);
417  initializeAnalysis(Registry);
418  initializeTransformUtils(Registry);
419  initializeInstCombine(Registry);
420  initializeTarget(Registry);
421  // For codegen passes, only passes that do IR to IR transformation are
422  // supported.
423  initializeExpandLargeDivRemLegacyPassPass(Registry);
424  initializeExpandLargeFpConvertLegacyPassPass(Registry);
425  initializeExpandMemCmpLegacyPassPass(Registry);
426  initializeScalarizeMaskedMemIntrinLegacyPassPass(Registry);
427  initializeSelectOptimizePass(Registry);
428  initializeCallBrPreparePass(Registry);
429  initializeCodeGenPrepareLegacyPassPass(Registry);
430  initializeAtomicExpandPass(Registry);
431  initializeWinEHPreparePass(Registry);
432  initializeDwarfEHPrepareLegacyPassPass(Registry);
433  initializeSafeStackLegacyPassPass(Registry);
434  initializeSjLjEHPreparePass(Registry);
435  initializePreISelIntrinsicLoweringLegacyPassPass(Registry);
436  initializeGlobalMergePass(Registry);
437  initializeIndirectBrExpandLegacyPassPass(Registry);
438  initializeInterleavedLoadCombinePass(Registry);
439  initializeInterleavedAccessPass(Registry);
440  initializeUnreachableBlockElimLegacyPassPass(Registry);
441  initializeExpandReductionsPass(Registry);
442  initializeExpandVectorPredicationPass(Registry);
443  initializeWasmEHPreparePass(Registry);
444  initializeWriteBitcodePassPass(Registry);
445  initializeReplaceWithVeclibLegacyPass(Registry);
446  initializeJMCInstrumenterPass(Registry);
447
448  SmallVector<PassPlugin, 1> PluginList;
449  PassPlugins.setCallback([&](const std::string &PluginPath) {
450    auto Plugin = PassPlugin::Load(PluginPath);
451    if (!Plugin)
452      report_fatal_error(Plugin.takeError(), /*gen_crash_diag=*/false);
453    PluginList.emplace_back(Plugin.get());
454  });
455
456  // Register the Target and CPU printer for --version.
457  cl::AddExtraVersionPrinter(sys::printDefaultTargetAndDetectedCPU);
458
459  cl::ParseCommandLineOptions(argc, argv,
460    "llvm .bc -> .bc modular optimizer and analysis printer\n");
461
462  // RemoveDIs debug-info transition: tests may request that we /try/ to use the
463  // new debug-info format, if it's built in.
464#ifdef EXPERIMENTAL_DEBUGINFO_ITERATORS
465  if (TryUseNewDbgInfoFormat) {
466    // If LLVM was built with support for this, turn the new debug-info format
467    // on.
468    UseNewDbgInfoFormat = true;
469  }
470#endif
471  (void)TryUseNewDbgInfoFormat;
472
473  LLVMContext Context;
474
475  // TODO: remove shouldForceLegacyPM().
476  const bool UseNPM = (!EnableLegacyPassManager && !shouldForceLegacyPM()) ||
477                      PassPipeline.getNumOccurrences() > 0;
478
479  if (UseNPM && !PassList.empty()) {
480    errs() << "The `opt -passname` syntax for the new pass manager is "
481              "not supported, please use `opt -passes=<pipeline>` (or the `-p` "
482              "alias for a more concise version).\n";
483    errs() << "See https://llvm.org/docs/NewPassManager.html#invoking-opt "
484              "for more details on the pass pipeline syntax.\n\n";
485    return 1;
486  }
487
488  if (!UseNPM && PluginList.size()) {
489    errs() << argv[0] << ": " << PassPlugins.ArgStr
490           << " specified with legacy PM.\n";
491    return 1;
492  }
493
494  // FIXME: once the legacy PM code is deleted, move runPassPipeline() here and
495  // construct the PassBuilder before parsing IR so we can reuse the same
496  // PassBuilder for print passes.
497  if (PrintPasses) {
498    printPasses(outs());
499    return 0;
500  }
501
502  TimeTracerRAII TimeTracer(argv[0]);
503
504  SMDiagnostic Err;
505
506  Context.setDiscardValueNames(DiscardValueNames);
507  if (!DisableDITypeMap)
508    Context.enableDebugTypeODRUniquing();
509
510  Expected<std::unique_ptr<ToolOutputFile>> RemarksFileOrErr =
511      setupLLVMOptimizationRemarks(Context, RemarksFilename, RemarksPasses,
512                                   RemarksFormat, RemarksWithHotness,
513                                   RemarksHotnessThreshold);
514  if (Error E = RemarksFileOrErr.takeError()) {
515    errs() << toString(std::move(E)) << '\n';
516    return 1;
517  }
518  std::unique_ptr<ToolOutputFile> RemarksFile = std::move(*RemarksFileOrErr);
519
520  // Load the input module...
521  auto SetDataLayout = [&](StringRef IRTriple,
522                           StringRef IRLayout) -> std::optional<std::string> {
523    // Data layout specified on the command line has the highest priority.
524    if (!ClDataLayout.empty())
525      return ClDataLayout;
526    // If an explicit data layout is already defined in the IR, don't infer.
527    if (!IRLayout.empty())
528      return std::nullopt;
529
530    // If an explicit triple was specified (either in the IR or on the
531    // command line), use that to infer the default data layout. However, the
532    // command line target triple should override the IR file target triple.
533    std::string TripleStr =
534        TargetTriple.empty() ? IRTriple.str() : Triple::normalize(TargetTriple);
535    // If the triple string is still empty, we don't fall back to
536    // sys::getDefaultTargetTriple() since we do not want to have differing
537    // behaviour dependent on the configured default triple. Therefore, if the
538    // user did not pass -mtriple or define an explicit triple/datalayout in
539    // the IR, we should default to an empty (default) DataLayout.
540    if (TripleStr.empty())
541      return std::nullopt;
542    // Otherwise we infer the DataLayout from the target machine.
543    Expected<std::unique_ptr<TargetMachine>> ExpectedTM =
544        codegen::createTargetMachineForTriple(TripleStr, GetCodeGenOptLevel());
545    if (!ExpectedTM) {
546      errs() << argv[0] << ": warning: failed to infer data layout: "
547             << toString(ExpectedTM.takeError()) << "\n";
548      return std::nullopt;
549    }
550    return (*ExpectedTM)->createDataLayout().getStringRepresentation();
551  };
552  std::unique_ptr<Module> M;
553  if (NoUpgradeDebugInfo)
554    M = parseAssemblyFileWithIndexNoUpgradeDebugInfo(
555            InputFilename, Err, Context, nullptr, SetDataLayout)
556            .Mod;
557  else
558    M = parseIRFile(InputFilename, Err, Context,
559                    ParserCallbacks(SetDataLayout));
560
561  if (!M) {
562    Err.print(argv[0], errs());
563    return 1;
564  }
565
566  // Strip debug info before running the verifier.
567  if (StripDebug)
568    StripDebugInfo(*M);
569
570  // Erase module-level named metadata, if requested.
571  if (StripNamedMetadata) {
572    while (!M->named_metadata_empty()) {
573      NamedMDNode *NMD = &*M->named_metadata_begin();
574      M->eraseNamedMetadata(NMD);
575    }
576  }
577
578  // If we are supposed to override the target triple, do so now.
579  if (!TargetTriple.empty())
580    M->setTargetTriple(Triple::normalize(TargetTriple));
581
582  // Immediately run the verifier to catch any problems before starting up the
583  // pass pipelines.  Otherwise we can crash on broken code during
584  // doInitialization().
585  if (!NoVerify && verifyModule(*M, &errs())) {
586    errs() << argv[0] << ": " << InputFilename
587           << ": error: input module is broken!\n";
588    return 1;
589  }
590
591  // Enable testing of whole program devirtualization on this module by invoking
592  // the facility for updating public visibility to linkage unit visibility when
593  // specified by an internal option. This is normally done during LTO which is
594  // not performed via opt.
595  updateVCallVisibilityInModule(
596      *M,
597      /*WholeProgramVisibilityEnabledInLTO=*/false,
598      // FIXME: These need linker information via a
599      // TBD new interface.
600      /*DynamicExportSymbols=*/{},
601      /*ValidateAllVtablesHaveTypeInfos=*/false,
602      /*IsVisibleToRegularObj=*/[](StringRef) { return true; });
603
604  // Figure out what stream we are supposed to write to...
605  std::unique_ptr<ToolOutputFile> Out;
606  std::unique_ptr<ToolOutputFile> ThinLinkOut;
607  if (NoOutput) {
608    if (!OutputFilename.empty())
609      errs() << "WARNING: The -o (output filename) option is ignored when\n"
610                "the --disable-output option is used.\n";
611  } else {
612    // Default to standard output.
613    if (OutputFilename.empty())
614      OutputFilename = "-";
615
616    std::error_code EC;
617    sys::fs::OpenFlags Flags =
618        OutputAssembly ? sys::fs::OF_TextWithCRLF : sys::fs::OF_None;
619    Out.reset(new ToolOutputFile(OutputFilename, EC, Flags));
620    if (EC) {
621      errs() << EC.message() << '\n';
622      return 1;
623    }
624
625    if (!ThinLinkBitcodeFile.empty()) {
626      ThinLinkOut.reset(
627          new ToolOutputFile(ThinLinkBitcodeFile, EC, sys::fs::OF_None));
628      if (EC) {
629        errs() << EC.message() << '\n';
630        return 1;
631      }
632    }
633  }
634
635  Triple ModuleTriple(M->getTargetTriple());
636  std::string CPUStr, FeaturesStr;
637  std::unique_ptr<TargetMachine> TM;
638  if (ModuleTriple.getArch()) {
639    CPUStr = codegen::getCPUStr();
640    FeaturesStr = codegen::getFeaturesStr();
641    Expected<std::unique_ptr<TargetMachine>> ExpectedTM =
642        codegen::createTargetMachineForTriple(ModuleTriple.str(),
643                                              GetCodeGenOptLevel());
644    if (auto E = ExpectedTM.takeError()) {
645      errs() << argv[0] << ": WARNING: failed to create target machine for '"
646             << ModuleTriple.str() << "': " << toString(std::move(E)) << "\n";
647    } else {
648      TM = std::move(*ExpectedTM);
649    }
650  } else if (ModuleTriple.getArchName() != "unknown" &&
651             ModuleTriple.getArchName() != "") {
652    errs() << argv[0] << ": unrecognized architecture '"
653           << ModuleTriple.getArchName() << "' provided.\n";
654    return 1;
655  }
656
657  // Override function attributes based on CPUStr, FeaturesStr, and command line
658  // flags.
659  codegen::setFunctionAttributes(CPUStr, FeaturesStr, *M);
660
661  // If the output is set to be emitted to standard out, and standard out is a
662  // console, print out a warning message and refuse to do it.  We don't
663  // impress anyone by spewing tons of binary goo to a terminal.
664  if (!Force && !NoOutput && !OutputAssembly)
665    if (CheckBitcodeOutputToConsole(Out->os()))
666      NoOutput = true;
667
668  if (OutputThinLTOBC) {
669    M->addModuleFlag(Module::Error, "EnableSplitLTOUnit", SplitLTOUnit);
670    if (UnifiedLTO)
671      M->addModuleFlag(Module::Error, "UnifiedLTO", 1);
672  }
673
674  // Add an appropriate TargetLibraryInfo pass for the module's triple.
675  TargetLibraryInfoImpl TLII(ModuleTriple);
676
677  // The -disable-simplify-libcalls flag actually disables all builtin optzns.
678  if (DisableSimplifyLibCalls)
679    TLII.disableAllFunctions();
680  else {
681    // Disable individual builtin functions in TargetLibraryInfo.
682    LibFunc F;
683    for (auto &FuncName : DisableBuiltins)
684      if (TLII.getLibFunc(FuncName, F))
685        TLII.setUnavailable(F);
686      else {
687        errs() << argv[0] << ": cannot disable nonexistent builtin function "
688               << FuncName << '\n';
689        return 1;
690      }
691  }
692
693  if (UseNPM) {
694    if (legacy::debugPassSpecified()) {
695      errs() << "-debug-pass does not work with the new PM, either use "
696                "-debug-pass-manager, or use the legacy PM\n";
697      return 1;
698    }
699    auto NumOLevel = OptLevelO0 + OptLevelO1 + OptLevelO2 + OptLevelO3 +
700                     OptLevelOs + OptLevelOz;
701    if (NumOLevel > 1) {
702      errs() << "Cannot specify multiple -O#\n";
703      return 1;
704    }
705    if (NumOLevel > 0 && (PassPipeline.getNumOccurrences() > 0)) {
706      errs() << "Cannot specify -O# and --passes=/--foo-pass, use "
707                "-passes='default<O#>,other-pass'\n";
708      return 1;
709    }
710    std::string Pipeline = PassPipeline;
711
712    if (OptLevelO0)
713      Pipeline = "default<O0>";
714    if (OptLevelO1)
715      Pipeline = "default<O1>";
716    if (OptLevelO2)
717      Pipeline = "default<O2>";
718    if (OptLevelO3)
719      Pipeline = "default<O3>";
720    if (OptLevelOs)
721      Pipeline = "default<Os>";
722    if (OptLevelOz)
723      Pipeline = "default<Oz>";
724    OutputKind OK = OK_NoOutput;
725    if (!NoOutput)
726      OK = OutputAssembly
727               ? OK_OutputAssembly
728               : (OutputThinLTOBC ? OK_OutputThinLTOBitcode : OK_OutputBitcode);
729
730    VerifierKind VK = VK_VerifyOut;
731    if (NoVerify)
732      VK = VK_NoVerifier;
733    else if (VerifyEach)
734      VK = VK_VerifyEachPass;
735
736    // The user has asked to use the new pass manager and provided a pipeline
737    // string. Hand off the rest of the functionality to the new code for that
738    // layer.
739    return runPassPipeline(argv[0], *M, TM.get(), &TLII, Out.get(),
740                           ThinLinkOut.get(), RemarksFile.get(), Pipeline,
741                           PluginList, OK, VK, PreserveAssemblyUseListOrder,
742                           PreserveBitcodeUseListOrder, EmitSummaryIndex,
743                           EmitModuleHash, EnableDebugify,
744                           VerifyDebugInfoPreserve, UnifiedLTO)
745               ? 0
746               : 1;
747  }
748
749  if (OptLevelO0 || OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz ||
750      OptLevelO3) {
751    errs() << "Cannot use -O# with legacy PM.\n";
752    return 1;
753  }
754  if (EmitSummaryIndex) {
755    errs() << "Cannot use -module-summary with legacy PM.\n";
756    return 1;
757  }
758  if (EmitModuleHash) {
759    errs() << "Cannot use -module-hash with legacy PM.\n";
760    return 1;
761  }
762  if (OutputThinLTOBC) {
763    errs() << "Cannot use -thinlto-bc with legacy PM.\n";
764    return 1;
765  }
766  // Create a PassManager to hold and optimize the collection of passes we are
767  // about to build. If the -debugify-each option is set, wrap each pass with
768  // the (-check)-debugify passes.
769  DebugifyCustomPassManager Passes;
770  DebugifyStatsMap DIStatsMap;
771  DebugInfoPerPass DebugInfoBeforePass;
772  if (DebugifyEach) {
773    Passes.setDebugifyMode(DebugifyMode::SyntheticDebugInfo);
774    Passes.setDIStatsMap(DIStatsMap);
775  } else if (VerifyEachDebugInfoPreserve) {
776    Passes.setDebugifyMode(DebugifyMode::OriginalDebugInfo);
777    Passes.setDebugInfoBeforePass(DebugInfoBeforePass);
778    if (!VerifyDIPreserveExport.empty())
779      Passes.setOrigDIVerifyBugsReportFilePath(VerifyDIPreserveExport);
780  }
781
782  bool AddOneTimeDebugifyPasses =
783      (EnableDebugify && !DebugifyEach) ||
784      (VerifyDebugInfoPreserve && !VerifyEachDebugInfoPreserve);
785
786  Passes.add(new TargetLibraryInfoWrapperPass(TLII));
787
788  // Add internal analysis passes from the target machine.
789  Passes.add(createTargetTransformInfoWrapperPass(TM ? TM->getTargetIRAnalysis()
790                                                     : TargetIRAnalysis()));
791
792  if (AddOneTimeDebugifyPasses) {
793    if (EnableDebugify) {
794      Passes.setDIStatsMap(DIStatsMap);
795      Passes.add(createDebugifyModulePass());
796    } else if (VerifyDebugInfoPreserve) {
797      Passes.setDebugInfoBeforePass(DebugInfoBeforePass);
798      Passes.add(createDebugifyModulePass(
799          DebugifyMode::OriginalDebugInfo, "",
800          &(Passes.getDebugInfoPerPass())));
801    }
802  }
803
804  if (TM) {
805    // FIXME: We should dyn_cast this when supported.
806    auto &LTM = static_cast<LLVMTargetMachine &>(*TM);
807    Pass *TPC = LTM.createPassConfig(Passes);
808    Passes.add(TPC);
809  }
810
811  // Create a new optimization pass for each one specified on the command line
812  for (unsigned i = 0; i < PassList.size(); ++i) {
813    const PassInfo *PassInf = PassList[i];
814    if (PassInf->getNormalCtor()) {
815      Pass *P = PassInf->getNormalCtor()();
816      if (P) {
817        // Add the pass to the pass manager.
818        Passes.add(P);
819        // If we are verifying all of the intermediate steps, add the verifier.
820        if (VerifyEach)
821          Passes.add(createVerifierPass());
822      }
823    } else
824      errs() << argv[0] << ": cannot create pass: "
825             << PassInf->getPassName() << "\n";
826  }
827
828  // Check that the module is well formed on completion of optimization
829  if (!NoVerify && !VerifyEach)
830    Passes.add(createVerifierPass());
831
832  if (AddOneTimeDebugifyPasses) {
833    if (EnableDebugify)
834      Passes.add(createCheckDebugifyModulePass(false));
835    else if (VerifyDebugInfoPreserve) {
836      if (!VerifyDIPreserveExport.empty())
837        Passes.setOrigDIVerifyBugsReportFilePath(VerifyDIPreserveExport);
838      Passes.add(createCheckDebugifyModulePass(
839          false, "", nullptr, DebugifyMode::OriginalDebugInfo,
840          &(Passes.getDebugInfoPerPass()), VerifyDIPreserveExport));
841    }
842  }
843
844  // In run twice mode, we want to make sure the output is bit-by-bit
845  // equivalent if we run the pass manager again, so setup two buffers and
846  // a stream to write to them. Note that llc does something similar and it
847  // may be worth to abstract this out in the future.
848  SmallVector<char, 0> Buffer;
849  SmallVector<char, 0> FirstRunBuffer;
850  std::unique_ptr<raw_svector_ostream> BOS;
851  raw_ostream *OS = nullptr;
852
853  const bool ShouldEmitOutput = !NoOutput;
854
855  // Write bitcode or assembly to the output as the last step...
856  if (ShouldEmitOutput || RunTwice) {
857    assert(Out);
858    OS = &Out->os();
859    if (RunTwice) {
860      BOS = std::make_unique<raw_svector_ostream>(Buffer);
861      OS = BOS.get();
862    }
863    if (OutputAssembly)
864      Passes.add(createPrintModulePass(*OS, "", PreserveAssemblyUseListOrder));
865    else
866      Passes.add(createBitcodeWriterPass(*OS, PreserveBitcodeUseListOrder));
867  }
868
869  // Before executing passes, print the final values of the LLVM options.
870  cl::PrintOptionValues();
871
872  if (!RunTwice) {
873    // Now that we have all of the passes ready, run them.
874    Passes.run(*M);
875  } else {
876    // If requested, run all passes twice with the same pass manager to catch
877    // bugs caused by persistent state in the passes.
878    std::unique_ptr<Module> M2(CloneModule(*M));
879    // Run all passes on the original module first, so the second run processes
880    // the clone to catch CloneModule bugs.
881    Passes.run(*M);
882    FirstRunBuffer = Buffer;
883    Buffer.clear();
884
885    Passes.run(*M2);
886
887    // Compare the two outputs and make sure they're the same
888    assert(Out);
889    if (Buffer.size() != FirstRunBuffer.size() ||
890        (memcmp(Buffer.data(), FirstRunBuffer.data(), Buffer.size()) != 0)) {
891      errs()
892          << "Running the pass manager twice changed the output.\n"
893             "Writing the result of the second run to the specified output.\n"
894             "To generate the one-run comparison binary, just run without\n"
895             "the compile-twice option\n";
896      if (ShouldEmitOutput) {
897        Out->os() << BOS->str();
898        Out->keep();
899      }
900      if (RemarksFile)
901        RemarksFile->keep();
902      return 1;
903    }
904    if (ShouldEmitOutput)
905      Out->os() << BOS->str();
906  }
907
908  if (DebugifyEach && !DebugifyExport.empty())
909    exportDebugifyStats(DebugifyExport, Passes.getDebugifyStatsMap());
910
911  // Declare success.
912  if (!NoOutput)
913    Out->keep();
914
915  if (RemarksFile)
916    RemarksFile->keep();
917
918  if (ThinLinkOut)
919    ThinLinkOut->keep();
920
921  return 0;
922}
923