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1 //===-LTO.h - LLVM Link Time 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 // This file declares functions and classes used to support LTO. It is intended
10 // to be used both by LTO classes as well as by clients (gold-plugin) that
11 // don't utilize the LTO code generator interfaces.
12 //
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_LTO_LTO_H
16 #define LLVM_LTO_LTO_H
18 #include "llvm/ADT/MapVector.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/ADT/StringSet.h"
21 #include "llvm/IR/DiagnosticInfo.h"
23 #include "llvm/LTO/Config.h"
24 #include "llvm/Linker/IRMover.h"
25 #include "llvm/Object/IRSymtab.h"
26 #include "llvm/Support/Error.h"
28 #include "llvm/Support/thread.h"
32 namespace llvm {
34 class BitcodeModule;
35 class Error;
36 class LLVMContext;
37 class MemoryBufferRef;
38 class Module;
39 class Target;
40 class raw_pwrite_stream;
42 /// Resolve linkage for prevailing symbols in the \p Index. Linkage changes
43 /// recorded in the index and the ThinLTO backends must apply the changes to
44 /// the module via thinLTOResolvePrevailingInModule.
45 ///
46 /// This is done for correctness (if value exported, ensure we always
47 /// emit a copy), and compile-time optimization (allow drop of duplicates).
49  ModuleSummaryIndex &Index,
50  function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
51  isPrevailing,
52  function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
53  recordNewLinkage);
55 /// Update the linkages in the given \p Index to mark exported values
56 /// as external and non-exported values as internal. The ThinLTO backends
57 /// must apply the changes to the Module via thinLTOInternalizeModule.
59  ModuleSummaryIndex &Index,
60  function_ref<bool(StringRef, GlobalValue::GUID)> isExported);
62 /// Computes a unique hash for the Module considering the current list of
63 /// export/import and other global analysis results.
64 /// The hash is produced in \p Key.
66  SmallString<40> &Key, const lto::Config &Conf,
67  const ModuleSummaryIndex &Index, StringRef ModuleID,
68  const FunctionImporter::ImportMapTy &ImportList,
69  const FunctionImporter::ExportSetTy &ExportList,
70  const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
71  const GVSummaryMapTy &DefinedGlobals,
72  const std::set<GlobalValue::GUID> &CfiFunctionDefs = {},
73  const std::set<GlobalValue::GUID> &CfiFunctionDecls = {});
75 namespace lto {
77 /// Given the original \p Path to an output file, replace any path
78 /// prefix matching \p OldPrefix with \p NewPrefix. Also, create the
79 /// resulting directory if it does not yet exist.
80 std::string getThinLTOOutputFile(const std::string &Path,
81  const std::string &OldPrefix,
82  const std::string &NewPrefix);
84 /// Setup optimization remarks.
85 Expected<std::unique_ptr<ToolOutputFile>>
87  bool LTOPassRemarksWithHotness, int Count = -1);
89 class LTO;
90 struct SymbolResolution;
91 class ThinBackendProc;
93 /// An input file. This is a symbol table wrapper that only exposes the
94 /// information that an LTO client should need in order to do symbol resolution.
95 class InputFile {
96 public:
97  class Symbol;
99 private:
100  // FIXME: Remove LTO class friendship once we have bitcode symbol tables.
101  friend LTO;
102  InputFile() = default;
104  std::vector<BitcodeModule> Mods;
105  SmallVector<char, 0> Strtab;
106  std::vector<Symbol> Symbols;
108  // [begin, end) for each module
109  std::vector<std::pair<size_t, size_t>> ModuleSymIndices;
111  StringRef TargetTriple, SourceFileName, COFFLinkerOpts;
112  std::vector<StringRef> ComdatTable;
114 public:
115  ~InputFile();
117  /// Create an InputFile.
120  /// The purpose of this class is to only expose the symbol information that an
121  /// LTO client should need in order to do symbol resolution.
123  friend LTO;
125  public:
126  Symbol(const irsymtab::Symbol &S) : irsymtab::Symbol(S) {}
142  };
144  /// A range over the symbols in this InputFile.
145  ArrayRef<Symbol> symbols() const { return Symbols; }
147  /// Returns linker options specified in the input file.
148  StringRef getCOFFLinkerOpts() const { return COFFLinkerOpts; }
150  /// Returns the path to the InputFile.
151  StringRef getName() const;
153  /// Returns the input file's target triple.
154  StringRef getTargetTriple() const { return TargetTriple; }
156  /// Returns the source file path specified at compile time.
157  StringRef getSourceFileName() const { return SourceFileName; }
159  // Returns a table with all the comdats used by this file.
160  ArrayRef<StringRef> getComdatTable() const { return ComdatTable; }
162 private:
163  ArrayRef<Symbol> module_symbols(unsigned I) const {
164  const auto &Indices = ModuleSymIndices[I];
165  return {Symbols.data() + Indices.first, Symbols.data() + Indices.second};
166  }
167 };
169 /// This class wraps an output stream for a native object. Most clients should
170 /// just be able to return an instance of this base class from the stream
171 /// callback, but if a client needs to perform some action after the stream is
172 /// written to, that can be done by deriving from this class and overriding the
173 /// destructor.
175 public:
176  NativeObjectStream(std::unique_ptr<raw_pwrite_stream> OS) : OS(std::move(OS)) {}
177  std::unique_ptr<raw_pwrite_stream> OS;
178  virtual ~NativeObjectStream() = default;
179 };
181 /// This type defines the callback to add a native object that is generated on
182 /// the fly.
183 ///
184 /// Stream callbacks must be thread safe.
185 typedef std::function<std::unique_ptr<NativeObjectStream>(unsigned Task)>
188 /// This is the type of a native object cache. To request an item from the
189 /// cache, pass a unique string as the Key. For hits, the cached file will be
190 /// added to the link and this function will return AddStreamFn(). For misses,
191 /// the cache will return a stream callback which must be called at most once to
192 /// produce content for the stream. The native object stream produced by the
193 /// stream callback will add the file to the link after the stream is written
194 /// to.
195 ///
196 /// Clients generally look like this:
197 ///
198 /// if (AddStreamFn AddStream = Cache(Task, Key))
199 /// ProduceContent(AddStream);
200 typedef std::function<AddStreamFn(unsigned Task, StringRef Key)>
203 /// A ThinBackend defines what happens after the thin-link phase during ThinLTO.
204 /// The details of this type definition aren't important; clients can only
205 /// create a ThinBackend using one of the create*ThinBackend() functions below.
206 typedef std::function<std::unique_ptr<ThinBackendProc>(
207  Config &C, ModuleSummaryIndex &CombinedIndex,
208  StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
209  AddStreamFn AddStream, NativeObjectCache Cache)>
212 /// This ThinBackend runs the individual backend jobs in-process.
213 ThinBackend createInProcessThinBackend(unsigned ParallelismLevel);
215 /// This ThinBackend writes individual module indexes to files, instead of
216 /// running the individual backend jobs. This backend is for distributed builds
217 /// where separate processes will invoke the real backends.
218 ///
219 /// To find the path to write the index to, the backend checks if the path has a
220 /// prefix of OldPrefix; if so, it replaces that prefix with NewPrefix. It then
221 /// appends ".thinlto.bc" and writes the index to that path. If
222 /// ShouldEmitImportsFiles is true it also writes a list of imported files to a
223 /// similar path with ".imports" appended instead.
224 /// LinkedObjectsFile is an output stream to write the list of object files for
225 /// the final ThinLTO linking. Can be nullptr.
226 /// OnWrite is callback which receives module identifier and notifies LTO user
227 /// that index file for the module (and optionally imports file) was created.
228 using IndexWriteCallback = std::function<void(const std::string &)>;
229 ThinBackend createWriteIndexesThinBackend(std::string OldPrefix,
230  std::string NewPrefix,
231  bool ShouldEmitImportsFiles,
232  raw_fd_ostream *LinkedObjectsFile,
233  IndexWriteCallback OnWrite);
235 /// This class implements a resolution-based interface to LLVM's LTO
236 /// functionality. It supports regular LTO, parallel LTO code generation and
237 /// ThinLTO. You can use it from a linker in the following way:
238 /// - Set hooks and code generation options (see lto::Config struct defined in
239 /// Config.h), and use the lto::Config object to create an lto::LTO object.
240 /// - Create lto::InputFile objects using lto::InputFile::create(), then use
241 /// the symbols() function to enumerate its symbols and compute a resolution
242 /// for each symbol (see SymbolResolution below).
243 /// - After the linker has visited each input file (and each regular object
244 /// file) and computed a resolution for each symbol, take each lto::InputFile
245 /// and pass it and an array of symbol resolutions to the add() function.
246 /// - Call the getMaxTasks() function to get an upper bound on the number of
247 /// native object files that LTO may add to the link.
248 /// - Call the run() function. This function will use the supplied AddStream
249 /// and Cache functions to add up to getMaxTasks() native object files to
250 /// the link.
251 class LTO {
252  friend InputFile;
254 public:
255  /// Create an LTO object. A default constructed LTO object has a reasonable
256  /// production configuration, but you can customize it by passing arguments to
257  /// this constructor.
258  /// FIXME: We do currently require the DiagHandler field to be set in Conf.
259  /// Until that is fixed, a Config argument is required.
260  LTO(Config Conf, ThinBackend Backend = nullptr,
261  unsigned ParallelCodeGenParallelismLevel = 1);
262  ~LTO();
264  /// Add an input file to the LTO link, using the provided symbol resolutions.
265  /// The symbol resolutions must appear in the enumeration order given by
266  /// InputFile::symbols().
267  Error add(std::unique_ptr<InputFile> Obj, ArrayRef<SymbolResolution> Res);
269  /// Returns an upper bound on the number of tasks that the client may expect.
270  /// This may only be called after all IR object files have been added. For a
271  /// full description of tasks see LTOBackend.h.
272  unsigned getMaxTasks() const;
274  /// Runs the LTO pipeline. This function calls the supplied AddStream
275  /// function to add native object files to the link.
276  ///
277  /// The Cache parameter is optional. If supplied, it will be used to cache
278  /// native object files and add them to the link.
279  ///
280  /// The client will receive at most one callback (via either AddStream or
281  /// Cache) for each task identifier.
282  Error run(AddStreamFn AddStream, NativeObjectCache Cache = nullptr);
284 private:
285  Config Conf;
287  struct RegularLTOState {
288  RegularLTOState(unsigned ParallelCodeGenParallelismLevel, Config &Conf);
290  uint64_t Size = 0;
291  unsigned Align = 0;
292  /// Record if at least one instance of the common was marked as prevailing
293  bool Prevailing = false;
294  };
295  std::map<std::string, CommonResolution> Commons;
297  unsigned ParallelCodeGenParallelismLevel;
298  LTOLLVMContext Ctx;
299  std::unique_ptr<Module> CombinedModule;
300  std::unique_ptr<IRMover> Mover;
302  // This stores the information about a regular LTO module that we have added
303  // to the link. It will either be linked immediately (for modules without
304  // summaries) or after summary-based dead stripping (for modules with
305  // summaries).
306  struct AddedModule {
307  std::unique_ptr<Module> M;
308  std::vector<GlobalValue *> Keep;
309  };
310  std::vector<AddedModule> ModsWithSummaries;
311  } RegularLTO;
313  struct ThinLTOState {
314  ThinLTOState(ThinBackend Backend);
316  ThinBackend Backend;
317  ModuleSummaryIndex CombinedIndex;
319  DenseMap<GlobalValue::GUID, StringRef> PrevailingModuleForGUID;
320  } ThinLTO;
322  // The global resolution for a particular (mangled) symbol name. This is in
323  // particular necessary to track whether each symbol can be internalized.
324  // Because any input file may introduce a new cross-partition reference, we
325  // cannot make any final internalization decisions until all input files have
326  // been added and the client has called run(). During run() we apply
327  // internalization decisions either directly to the module (for regular LTO)
328  // or to the combined index (for ThinLTO).
329  struct GlobalResolution {
330  /// The unmangled name of the global.
331  std::string IRName;
333  /// Keep track if the symbol is visible outside of a module with a summary
334  /// (i.e. in either a regular object or a regular LTO module without a
335  /// summary).
336  bool VisibleOutsideSummary = false;
338  bool UnnamedAddr = true;
340  /// True if module contains the prevailing definition.
341  bool Prevailing = false;
343  /// Returns true if module contains the prevailing definition and symbol is
344  /// an IR symbol. For example when module-level inline asm block is used,
345  /// symbol can be prevailing in module but have no IR name.
346  bool isPrevailingIRSymbol() const { return Prevailing && !IRName.empty(); }
348  /// This field keeps track of the partition number of this global. The
349  /// regular LTO object is partition 0, while each ThinLTO object has its own
350  /// partition number from 1 onwards.
351  ///
352  /// Any global that is defined or used by more than one partition, or that
353  /// is referenced externally, may not be internalized.
354  ///
355  /// Partitions generally have a one-to-one correspondence with tasks, except
356  /// that we use partition 0 for all parallel LTO code generation partitions.
357  /// Any partitioning of the combined LTO object is done internally by the
358  /// LTO backend.
359  unsigned Partition = Unknown;
361  /// Special partition numbers.
362  enum : unsigned {
363  /// A partition number has not yet been assigned to this global.
364  Unknown = -1u,
366  /// This global is either used by more than one partition or has an
367  /// external reference, and therefore cannot be internalized.
368  External = -2u,
370  /// The RegularLTO partition
371  RegularLTO = 0,
372  };
373  };
375  // Global mapping from mangled symbol names to resolutions.
376  StringMap<GlobalResolution> GlobalResolutions;
378  void addModuleToGlobalRes(ArrayRef<InputFile::Symbol> Syms,
379  ArrayRef<SymbolResolution> Res, unsigned Partition,
380  bool InSummary);
382  // These functions take a range of symbol resolutions [ResI, ResE) and consume
383  // the resolutions used by a single input module by incrementing ResI. After
384  // these functions return, [ResI, ResE) will refer to the resolution range for
385  // the remaining modules in the InputFile.
386  Error addModule(InputFile &Input, unsigned ModI,
387  const SymbolResolution *&ResI, const SymbolResolution *ResE);
390  addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
391  const SymbolResolution *&ResI, const SymbolResolution *ResE);
392  Error linkRegularLTO(RegularLTOState::AddedModule Mod,
393  bool LivenessFromIndex);
395  Error addThinLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
396  const SymbolResolution *&ResI, const SymbolResolution *ResE);
398  Error runRegularLTO(AddStreamFn AddStream);
399  Error runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache);
401  mutable bool CalledGetMaxTasks = false;
403  // Use Optional to distinguish false from not yet initialized.
404  Optional<bool> EnableSplitLTOUnit;
405 };
407 /// The resolution for a symbol. The linker must provide a SymbolResolution for
408 /// each global symbol based on its internal resolution of that symbol.
411  : Prevailing(0), FinalDefinitionInLinkageUnit(0), VisibleToRegularObj(0),
412  LinkerRedefined(0) {}
414  /// The linker has chosen this definition of the symbol.
415  unsigned Prevailing : 1;
417  /// The definition of this symbol is unpreemptable at runtime and is known to
418  /// be in this linkage unit.
421  /// The definition of this symbol is visible outside of the LTO unit.
422  unsigned VisibleToRegularObj : 1;
424  /// Linker redefined version of the symbol which appeared in -wrap or -defsym
425  /// linker option.
426  unsigned LinkerRedefined : 1;
427 };
429 } // namespace lto
430 } // namespace llvm
432 #endif
NativeObjectStream(std::unique_ptr< raw_pwrite_stream > OS)
Definition: LTO.h:176
uint64_t CallInst * C
GlobalValue::VisibilityTypes getVisibility() const
Definition: IRSymtab.h:185
ArrayRef< Symbol > symbols() const
A range over the symbols in this InputFile.
Definition: LTO.h:145
constexpr char Align[]
Key for Kernel::Arg::Metadata::mAlign.
StringRef getCOFFWeakExternalFallback() const
COFF-specific: for weak externals, returns the name of the symbol that is used as a fallback if the w...
Definition: IRSymtab.h:217
ArrayRef< StringRef > getComdatTable() const
Definition: LTO.h:160
Expected< std::unique_ptr< ToolOutputFile > > setupOptimizationRemarks(LLVMContext &Context, StringRef LTORemarksFilename, bool LTOPassRemarksWithHotness, int Count=-1)
Setup optimization remarks.
Definition: LTO.cpp:1266
LLVMContext & Context
unsigned Prevailing
The linker has chosen this definition of the symbol.
Definition: LTO.h:415
bool isTLS() const
Definition: IRSymtab.h:194
uint64_t GUID
Declare a type to represent a global unique identifier for a global value.
Definition: GlobalValue.h:492
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Symbol(const irsymtab::Symbol &S)
Definition: LTO.h:126
cl::opt< std::string > LTORemarksFilename("lto-pass-remarks-output", cl::desc("Output filename for pass remarks"), cl::value_desc("filename"))
Contains the information needed by linkers for symbol resolution, as well as by the LTO implementatio...
Definition: IRSymtab.h:86
The purpose of this class is to only expose the symbol information that an LTO client should need in ...
Definition: LTO.h:122
unsigned LinkerRedefined
Linker redefined version of the symbol which appeared in -wrap or -defsym linker option.
Definition: LTO.h:426
bool isExecutable() const
Definition: IRSymtab.h:203
The resolution for a symbol.
Definition: LTO.h:409
This class implements a map that also provides access to all stored values in a deterministic order...
Definition: MapVector.h:37
static Expected< std::unique_ptr< InputFile > > create(MemoryBufferRef Object)
Create an InputFile.
Definition: LTO.cpp:389
std::function< void(const std::string &)> IndexWriteCallback
This ThinBackend writes individual module indexes to files, instead of running the individual backend...
Definition: LTO.h:228
bool canBeOmittedFromSymbolTable() const
Definition: IRSymtab.h:196
ThinBackend createWriteIndexesThinBackend(std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles, raw_fd_ostream *LinkedObjectsFile, IndexWriteCallback OnWrite)
Definition: LTO.cpp:1151
StringMap< FunctionsToImportTy > ImportMapTy
The map contains an entry for every module to import from, the key being the module identifier to pas...
std::unique_ptr< raw_pwrite_stream > OS
Definition: LTO.h:177
std::function< std::unique_ptr< NativeObjectStream >unsigned Task)> AddStreamFn
This type defines the callback to add a native object that is generated on the fly.
Definition: LTO.h:186
Definition: BitVector.h:937
Represents a module in a bitcode file.
Definition: BitcodeReader.h:57
StringRef getSourceFileName() const
Returns the source file path specified at compile time.
Definition: LTO.h:157
std::unordered_set< GlobalValue::GUID > ExportSetTy
The set contains an entry for every global value the module exports.
Tagged union holding either a T or a Error.
Definition: CachePruning.h:22
bool isCommon() const
Definition: IRSymtab.h:191
PAL metadata keys.
StringRef getTargetTriple() const
Returns the input file&#39;s target triple.
Definition: LTO.h:154
DenseMap< GlobalValue::GUID, GlobalValueSummary * > GVSummaryMapTy
Map of global value GUID to its summary, used to identify values defined in a particular module...
cl::opt< bool > LTOPassRemarksWithHotness("lto-pass-remarks-with-hotness", cl::desc("With PGO, include profile count in optimization remarks"), cl::Hidden)
bool isUndefined() const
Definition: IRSymtab.h:189
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
An input file.
Definition: LTO.h:95
This class implements a resolution-based interface to LLVM&#39;s LTO functionality.
Definition: LTO.h:251
Class to hold module path string table and global value map, and encapsulate methods for operating on...
StringRef getName() const
Returns the mangled symbol name.
Definition: IRSymtab.h:173
std::unique_ptr< Module > M
Definition: LTO.h:307
std::function< AddStreamFn(unsigned Task, StringRef Key)> NativeObjectCache
This is the type of a native object cache.
Definition: LTO.h:201
uint32_t getCommonAlignment() const
Definition: IRSymtab.h:210
This class wraps an output stream for a native object.
Definition: LTO.h:174
bool isIndirect() const
Definition: IRSymtab.h:192
void thinLTOResolvePrevailingInIndex(ModuleSummaryIndex &Index, function_ref< bool(GlobalValue::GUID, const GlobalValueSummary *)> isPrevailing, function_ref< void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)> recordNewLinkage)
Resolve linkage for prevailing symbols in the Index.
Definition: LTO.cpp:337
LTO configuration.
Definition: Config.h:35
This represents a symbol that has been read from a storage::Symbol and possibly a storage::Uncommon...
Definition: IRSymtab.h:161
const T * data() const
Definition: ArrayRef.h:145
StringRef getSectionName() const
Definition: IRSymtab.h:222
std::function< std::unique_ptr< ThinBackendProc > Config &C, ModuleSummaryIndex &CombinedIndex, StringMap< GVSummaryMapTy > &ModuleToDefinedGVSummaries, AddStreamFn AddStream, NativeObjectCache Cache)> ThinBackend
A ThinBackend defines what happens after the thin-link phase during ThinLTO.
Definition: LTO.h:210
int getComdatIndex() const
Returns the index into the comdat table (see Reader::getComdatTable()), or -1 if not a comdat member...
Definition: IRSymtab.h:181
void computeLTOCacheKey(SmallString< 40 > &Key, const lto::Config &Conf, const ModuleSummaryIndex &Index, StringRef ModuleID, const FunctionImporter::ImportMapTy &ImportList, const FunctionImporter::ExportSetTy &ExportList, const std::map< GlobalValue::GUID, GlobalValue::LinkageTypes > &ResolvedODR, const GVSummaryMapTy &DefinedGlobals, const std::set< GlobalValue::GUID > &CfiFunctionDefs={}, const std::set< GlobalValue::GUID > &CfiFunctionDecls={})
Computes a unique hash for the Module considering the current list of export/import and other global ...
Definition: LTO.cpp:68
The access may modify the value stored in memory.
StringMap - This is an unconventional map that is specialized for handling keys that are "strings"...
Definition: StringMap.h:219
An enumeration for the kinds of linkage for global values.
Definition: GlobalValue.h:47
ThinBackend createInProcessThinBackend(unsigned ParallelismLevel)
This ThinBackend runs the individual backend jobs in-process.
Definition: LTO.cpp:1063
bool isWeak() const
Definition: IRSymtab.h:190
std::vector< GlobalValue * > Keep
Definition: LTO.h:308
A raw_ostream that writes to a file descriptor.
Definition: raw_ostream.h:365
#define I(x, y, z)
Definition: MD5.cpp:58
uint32_t Size
Definition: Profile.cpp:46
unsigned VisibleToRegularObj
The definition of this symbol is visible outside of the LTO unit.
Definition: LTO.h:422
ModuleSummaryIndex.h This file contains the declarations the classes that hold the module index and s...
StringRef getCOFFLinkerOpts() const
Returns linker options specified in the input file.
Definition: LTO.h:148
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
uint64_t getCommonSize() const
Definition: IRSymtab.h:205
A derived class of LLVMContext that initializes itself according to a given Config object...
Definition: Config.h:205
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
unsigned FinalDefinitionInLinkageUnit
The definition of this symbol is unpreemptable at runtime and is known to be in this linkage unit...
Definition: LTO.h:419
std::string getThinLTOOutputFile(const std::string &Path, const std::string &OldPrefix, const std::string &NewPrefix)
Given the original Path to an output file, replace any path prefix matching OldPrefix with NewPrefix...
Definition: LTO.cpp:1076
void thinLTOInternalizeAndPromoteInIndex(ModuleSummaryIndex &Index, function_ref< bool(StringRef, GlobalValue::GUID)> isExported)
Update the linkages in the given Index to mark exported values as external and non-exported values as...
Definition: LTO.cpp:379