1 //===- PassManager.h - Pass management infrastructure -----------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 /// \file 10 /// 11 /// This header defines various interfaces for pass management in LLVM. There 12 /// is no "pass" interface in LLVM per se. Instead, an instance of any class 13 /// which supports a method to 'run' it over a unit of IR can be used as 14 /// a pass. A pass manager is generally a tool to collect a sequence of passes 15 /// which run over a particular IR construct, and run each of them in sequence 16 /// over each such construct in the containing IR construct. As there is no 17 /// containing IR construct for a Module, a manager for passes over modules 18 /// forms the base case which runs its managed passes in sequence over the 19 /// single module provided. 20 /// 21 /// The core IR library provides managers for running passes over 22 /// modules and functions. 23 /// 24 /// * FunctionPassManager can run over a Module, runs each pass over 25 /// a Function. 26 /// * ModulePassManager must be directly run, runs each pass over the Module. 27 /// 28 /// Note that the implementations of the pass managers use concept-based 29 /// polymorphism as outlined in the "Value Semantics and Concept-based 30 /// Polymorphism" talk (or its abbreviated sibling "Inheritance Is The Base 31 /// Class of Evil") by Sean Parent: 32 /// * http://github.com/sean-parent/sean-parent.github.com/wiki/Papers-and-Presentations 33 /// * http://www.youtube.com/watch?v=_BpMYeUFXv8 34 /// * http://channel9.msdn.com/Events/GoingNative/2013/Inheritance-Is-The-Base-Class-of-Evil 35 /// 36 //===----------------------------------------------------------------------===// 37 38 #ifndef LLVM_IR_PASSMANAGER_H 39 #define LLVM_IR_PASSMANAGER_H 40 41 #include "llvm/ADT/DenseMap.h" 42 #include "llvm/ADT/SmallPtrSet.h" 43 #include "llvm/ADT/StringRef.h" 44 #include "llvm/ADT/TinyPtrVector.h" 45 #include "llvm/IR/Function.h" 46 #include "llvm/IR/Module.h" 47 #include "llvm/IR/PassManagerInternal.h" 48 #include "llvm/Support/Debug.h" 49 #include "llvm/Support/TypeName.h" 50 #include "llvm/Support/raw_ostream.h" 51 #include <algorithm> 52 #include <cassert> 53 #include <cstring> 54 #include <iterator> 55 #include <list> 56 #include <memory> 57 #include <tuple> 58 #include <type_traits> 59 #include <utility> 60 #include <vector> 61 62 namespace llvm { 63 64 /// A special type used by analysis passes to provide an address that 65 /// identifies that particular analysis pass type. 66 /// 67 /// Analysis passes should have a static data member of this type and derive 68 /// from the \c AnalysisInfoMixin to get a static ID method used to identify 69 /// the analysis in the pass management infrastructure. 70 struct alignas(8) AnalysisKey {}; 71 72 /// A special type used to provide an address that identifies a set of related 73 /// analyses. These sets are primarily used below to mark sets of analyses as 74 /// preserved. 75 /// 76 /// For example, a transformation can indicate that it preserves the CFG of a 77 /// function by preserving the appropriate AnalysisSetKey. An analysis that 78 /// depends only on the CFG can then check if that AnalysisSetKey is preserved; 79 /// if it is, the analysis knows that it itself is preserved. 80 struct alignas(8) AnalysisSetKey {}; 81 82 /// This templated class represents "all analyses that operate over \<a 83 /// particular IR unit\>" (e.g. a Function or a Module) in instances of 84 /// PreservedAnalysis. 85 /// 86 /// This lets a transformation say e.g. "I preserved all function analyses". 87 /// 88 /// Note that you must provide an explicit instantiation declaration and 89 /// definition for this template in order to get the correct behavior on 90 /// Windows. Otherwise, the address of SetKey will not be stable. 91 template <typename IRUnitT> class AllAnalysesOn { 92 public: ID()93 static AnalysisSetKey *ID() { return &SetKey; } 94 95 private: 96 static AnalysisSetKey SetKey; 97 }; 98 99 template <typename IRUnitT> AnalysisSetKey AllAnalysesOn<IRUnitT>::SetKey; 100 101 extern template class AllAnalysesOn<Module>; 102 extern template class AllAnalysesOn<Function>; 103 104 /// Represents analyses that only rely on functions' control flow. 105 /// 106 /// This can be used with \c PreservedAnalyses to mark the CFG as preserved and 107 /// to query whether it has been preserved. 108 /// 109 /// The CFG of a function is defined as the set of basic blocks and the edges 110 /// between them. Changing the set of basic blocks in a function is enough to 111 /// mutate the CFG. Mutating the condition of a branch or argument of an 112 /// invoked function does not mutate the CFG, but changing the successor labels 113 /// of those instructions does. 114 class CFGAnalyses { 115 public: ID()116 static AnalysisSetKey *ID() { return &SetKey; } 117 118 private: 119 static AnalysisSetKey SetKey; 120 }; 121 122 /// A set of analyses that are preserved following a run of a transformation 123 /// pass. 124 /// 125 /// Transformation passes build and return these objects to communicate which 126 /// analyses are still valid after the transformation. For most passes this is 127 /// fairly simple: if they don't change anything all analyses are preserved, 128 /// otherwise only a short list of analyses that have been explicitly updated 129 /// are preserved. 130 /// 131 /// This class also lets transformation passes mark abstract *sets* of analyses 132 /// as preserved. A transformation that (say) does not alter the CFG can 133 /// indicate such by marking a particular AnalysisSetKey as preserved, and 134 /// then analyses can query whether that AnalysisSetKey is preserved. 135 /// 136 /// Finally, this class can represent an "abandoned" analysis, which is 137 /// not preserved even if it would be covered by some abstract set of analyses. 138 /// 139 /// Given a `PreservedAnalyses` object, an analysis will typically want to 140 /// figure out whether it is preserved. In the example below, MyAnalysisType is 141 /// preserved if it's not abandoned, and (a) it's explicitly marked as 142 /// preserved, (b), the set AllAnalysesOn<MyIRUnit> is preserved, or (c) both 143 /// AnalysisSetA and AnalysisSetB are preserved. 144 /// 145 /// ``` 146 /// auto PAC = PA.getChecker<MyAnalysisType>(); 147 /// if (PAC.preserved() || PAC.preservedSet<AllAnalysesOn<MyIRUnit>>() || 148 /// (PAC.preservedSet<AnalysisSetA>() && 149 /// PAC.preservedSet<AnalysisSetB>())) { 150 /// // The analysis has been successfully preserved ... 151 /// } 152 /// ``` 153 class PreservedAnalyses { 154 public: 155 /// Convenience factory function for the empty preserved set. none()156 static PreservedAnalyses none() { return PreservedAnalyses(); } 157 158 /// Construct a special preserved set that preserves all passes. all()159 static PreservedAnalyses all() { 160 PreservedAnalyses PA; 161 PA.PreservedIDs.insert(&AllAnalysesKey); 162 return PA; 163 } 164 165 /// Construct a preserved analyses object with a single preserved set. 166 template <typename AnalysisSetT> allInSet()167 static PreservedAnalyses allInSet() { 168 PreservedAnalyses PA; 169 PA.preserveSet<AnalysisSetT>(); 170 return PA; 171 } 172 173 /// Mark an analysis as preserved. preserve()174 template <typename AnalysisT> void preserve() { preserve(AnalysisT::ID()); } 175 176 /// Given an analysis's ID, mark the analysis as preserved, adding it 177 /// to the set. preserve(AnalysisKey * ID)178 void preserve(AnalysisKey *ID) { 179 // Clear this ID from the explicit not-preserved set if present. 180 NotPreservedAnalysisIDs.erase(ID); 181 182 // If we're not already preserving all analyses (other than those in 183 // NotPreservedAnalysisIDs). 184 if (!areAllPreserved()) 185 PreservedIDs.insert(ID); 186 } 187 188 /// Mark an analysis set as preserved. preserveSet()189 template <typename AnalysisSetT> void preserveSet() { 190 preserveSet(AnalysisSetT::ID()); 191 } 192 193 /// Mark an analysis set as preserved using its ID. preserveSet(AnalysisSetKey * ID)194 void preserveSet(AnalysisSetKey *ID) { 195 // If we're not already in the saturated 'all' state, add this set. 196 if (!areAllPreserved()) 197 PreservedIDs.insert(ID); 198 } 199 200 /// Mark an analysis as abandoned. 201 /// 202 /// An abandoned analysis is not preserved, even if it is nominally covered 203 /// by some other set or was previously explicitly marked as preserved. 204 /// 205 /// Note that you can only abandon a specific analysis, not a *set* of 206 /// analyses. abandon()207 template <typename AnalysisT> void abandon() { abandon(AnalysisT::ID()); } 208 209 /// Mark an analysis as abandoned using its ID. 210 /// 211 /// An abandoned analysis is not preserved, even if it is nominally covered 212 /// by some other set or was previously explicitly marked as preserved. 213 /// 214 /// Note that you can only abandon a specific analysis, not a *set* of 215 /// analyses. abandon(AnalysisKey * ID)216 void abandon(AnalysisKey *ID) { 217 PreservedIDs.erase(ID); 218 NotPreservedAnalysisIDs.insert(ID); 219 } 220 221 /// Intersect this set with another in place. 222 /// 223 /// This is a mutating operation on this preserved set, removing all 224 /// preserved passes which are not also preserved in the argument. intersect(const PreservedAnalyses & Arg)225 void intersect(const PreservedAnalyses &Arg) { 226 if (Arg.areAllPreserved()) 227 return; 228 if (areAllPreserved()) { 229 *this = Arg; 230 return; 231 } 232 // The intersection requires the *union* of the explicitly not-preserved 233 // IDs and the *intersection* of the preserved IDs. 234 for (auto ID : Arg.NotPreservedAnalysisIDs) { 235 PreservedIDs.erase(ID); 236 NotPreservedAnalysisIDs.insert(ID); 237 } 238 for (auto ID : PreservedIDs) 239 if (!Arg.PreservedIDs.count(ID)) 240 PreservedIDs.erase(ID); 241 } 242 243 /// Intersect this set with a temporary other set in place. 244 /// 245 /// This is a mutating operation on this preserved set, removing all 246 /// preserved passes which are not also preserved in the argument. intersect(PreservedAnalyses && Arg)247 void intersect(PreservedAnalyses &&Arg) { 248 if (Arg.areAllPreserved()) 249 return; 250 if (areAllPreserved()) { 251 *this = std::move(Arg); 252 return; 253 } 254 // The intersection requires the *union* of the explicitly not-preserved 255 // IDs and the *intersection* of the preserved IDs. 256 for (auto ID : Arg.NotPreservedAnalysisIDs) { 257 PreservedIDs.erase(ID); 258 NotPreservedAnalysisIDs.insert(ID); 259 } 260 for (auto ID : PreservedIDs) 261 if (!Arg.PreservedIDs.count(ID)) 262 PreservedIDs.erase(ID); 263 } 264 265 /// A checker object that makes it easy to query for whether an analysis or 266 /// some set covering it is preserved. 267 class PreservedAnalysisChecker { 268 friend class PreservedAnalyses; 269 270 const PreservedAnalyses &PA; 271 AnalysisKey *const ID; 272 const bool IsAbandoned; 273 274 /// A PreservedAnalysisChecker is tied to a particular Analysis because 275 /// `preserved()` and `preservedSet()` both return false if the Analysis 276 /// was abandoned. PreservedAnalysisChecker(const PreservedAnalyses & PA,AnalysisKey * ID)277 PreservedAnalysisChecker(const PreservedAnalyses &PA, AnalysisKey *ID) 278 : PA(PA), ID(ID), IsAbandoned(PA.NotPreservedAnalysisIDs.count(ID)) {} 279 280 public: 281 /// Returns true if the checker's analysis was not abandoned and either 282 /// - the analysis is explicitly preserved or 283 /// - all analyses are preserved. preserved()284 bool preserved() { 285 return !IsAbandoned && (PA.PreservedIDs.count(&AllAnalysesKey) || 286 PA.PreservedIDs.count(ID)); 287 } 288 289 /// Returns true if the checker's analysis was not abandoned and either 290 /// - \p AnalysisSetT is explicitly preserved or 291 /// - all analyses are preserved. preservedSet()292 template <typename AnalysisSetT> bool preservedSet() { 293 AnalysisSetKey *SetID = AnalysisSetT::ID(); 294 return !IsAbandoned && (PA.PreservedIDs.count(&AllAnalysesKey) || 295 PA.PreservedIDs.count(SetID)); 296 } 297 }; 298 299 /// Build a checker for this `PreservedAnalyses` and the specified analysis 300 /// type. 301 /// 302 /// You can use the returned object to query whether an analysis was 303 /// preserved. See the example in the comment on `PreservedAnalysis`. getChecker()304 template <typename AnalysisT> PreservedAnalysisChecker getChecker() const { 305 return PreservedAnalysisChecker(*this, AnalysisT::ID()); 306 } 307 308 /// Build a checker for this `PreservedAnalyses` and the specified analysis 309 /// ID. 310 /// 311 /// You can use the returned object to query whether an analysis was 312 /// preserved. See the example in the comment on `PreservedAnalysis`. getChecker(AnalysisKey * ID)313 PreservedAnalysisChecker getChecker(AnalysisKey *ID) const { 314 return PreservedAnalysisChecker(*this, ID); 315 } 316 317 /// Test whether all analyses are preserved (and none are abandoned). 318 /// 319 /// This is used primarily to optimize for the common case of a transformation 320 /// which makes no changes to the IR. areAllPreserved()321 bool areAllPreserved() const { 322 return NotPreservedAnalysisIDs.empty() && 323 PreservedIDs.count(&AllAnalysesKey); 324 } 325 326 /// Directly test whether a set of analyses is preserved. 327 /// 328 /// This is only true when no analyses have been explicitly abandoned. allAnalysesInSetPreserved()329 template <typename AnalysisSetT> bool allAnalysesInSetPreserved() const { 330 return allAnalysesInSetPreserved(AnalysisSetT::ID()); 331 } 332 333 /// Directly test whether a set of analyses is preserved. 334 /// 335 /// This is only true when no analyses have been explicitly abandoned. allAnalysesInSetPreserved(AnalysisSetKey * SetID)336 bool allAnalysesInSetPreserved(AnalysisSetKey *SetID) const { 337 return NotPreservedAnalysisIDs.empty() && 338 (PreservedIDs.count(&AllAnalysesKey) || PreservedIDs.count(SetID)); 339 } 340 341 private: 342 /// A special key used to indicate all analyses. 343 static AnalysisSetKey AllAnalysesKey; 344 345 /// The IDs of analyses and analysis sets that are preserved. 346 SmallPtrSet<void *, 2> PreservedIDs; 347 348 /// The IDs of explicitly not-preserved analyses. 349 /// 350 /// If an analysis in this set is covered by a set in `PreservedIDs`, we 351 /// consider it not-preserved. That is, `NotPreservedAnalysisIDs` always 352 /// "wins" over analysis sets in `PreservedIDs`. 353 /// 354 /// Also, a given ID should never occur both here and in `PreservedIDs`. 355 SmallPtrSet<AnalysisKey *, 2> NotPreservedAnalysisIDs; 356 }; 357 358 // Forward declare the analysis manager template. 359 template <typename IRUnitT, typename... ExtraArgTs> class AnalysisManager; 360 361 /// A CRTP mix-in to automatically provide informational APIs needed for 362 /// passes. 363 /// 364 /// This provides some boilerplate for types that are passes. 365 template <typename DerivedT> struct PassInfoMixin { 366 /// Gets the name of the pass we are mixed into. namePassInfoMixin367 static StringRef name() { 368 static_assert(std::is_base_of<PassInfoMixin, DerivedT>::value, 369 "Must pass the derived type as the template argument!"); 370 StringRef Name = getTypeName<DerivedT>(); 371 if (Name.startswith("llvm::")) 372 Name = Name.drop_front(strlen("llvm::")); 373 return Name; 374 } 375 }; 376 377 /// A CRTP mix-in that provides informational APIs needed for analysis passes. 378 /// 379 /// This provides some boilerplate for types that are analysis passes. It 380 /// automatically mixes in \c PassInfoMixin. 381 template <typename DerivedT> 382 struct AnalysisInfoMixin : PassInfoMixin<DerivedT> { 383 /// Returns an opaque, unique ID for this analysis type. 384 /// 385 /// This ID is a pointer type that is guaranteed to be 8-byte aligned and thus 386 /// suitable for use in sets, maps, and other data structures that use the low 387 /// bits of pointers. 388 /// 389 /// Note that this requires the derived type provide a static \c AnalysisKey 390 /// member called \c Key. 391 /// 392 /// FIXME: The only reason the mixin type itself can't declare the Key value 393 /// is that some compilers cannot correctly unique a templated static variable 394 /// so it has the same addresses in each instantiation. The only currently 395 /// known platform with this limitation is Windows DLL builds, specifically 396 /// building each part of LLVM as a DLL. If we ever remove that build 397 /// configuration, this mixin can provide the static key as well. IDAnalysisInfoMixin398 static AnalysisKey *ID() { 399 static_assert(std::is_base_of<AnalysisInfoMixin, DerivedT>::value, 400 "Must pass the derived type as the template argument!"); 401 return &DerivedT::Key; 402 } 403 }; 404 405 /// Manages a sequence of passes over a particular unit of IR. 406 /// 407 /// A pass manager contains a sequence of passes to run over a particular unit 408 /// of IR (e.g. Functions, Modules). It is itself a valid pass over that unit of 409 /// IR, and when run over some given IR will run each of its contained passes in 410 /// sequence. Pass managers are the primary and most basic building block of a 411 /// pass pipeline. 412 /// 413 /// When you run a pass manager, you provide an \c AnalysisManager<IRUnitT> 414 /// argument. The pass manager will propagate that analysis manager to each 415 /// pass it runs, and will call the analysis manager's invalidation routine with 416 /// the PreservedAnalyses of each pass it runs. 417 template <typename IRUnitT, 418 typename AnalysisManagerT = AnalysisManager<IRUnitT>, 419 typename... ExtraArgTs> 420 class PassManager : public PassInfoMixin< 421 PassManager<IRUnitT, AnalysisManagerT, ExtraArgTs...>> { 422 public: 423 /// Construct a pass manager. 424 /// 425 /// If \p DebugLogging is true, we'll log our progress to llvm::dbgs(). DebugLogging(DebugLogging)426 explicit PassManager(bool DebugLogging = false) : DebugLogging(DebugLogging) {} 427 428 // FIXME: These are equivalent to the default move constructor/move 429 // assignment. However, using = default triggers linker errors due to the 430 // explicit instantiations below. Find away to use the default and remove the 431 // duplicated code here. PassManager(PassManager && Arg)432 PassManager(PassManager &&Arg) 433 : Passes(std::move(Arg.Passes)), 434 DebugLogging(std::move(Arg.DebugLogging)) {} 435 436 PassManager &operator=(PassManager &&RHS) { 437 Passes = std::move(RHS.Passes); 438 DebugLogging = std::move(RHS.DebugLogging); 439 return *this; 440 } 441 442 /// Run all of the passes in this manager over the given unit of IR. 443 /// ExtraArgs are passed to each pass. run(IRUnitT & IR,AnalysisManagerT & AM,ExtraArgTs...ExtraArgs)444 PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM, 445 ExtraArgTs... ExtraArgs) { 446 PreservedAnalyses PA = PreservedAnalyses::all(); 447 448 if (DebugLogging) 449 dbgs() << "Starting " << getTypeName<IRUnitT>() << " pass manager run.\n"; 450 451 for (unsigned Idx = 0, Size = Passes.size(); Idx != Size; ++Idx) { 452 if (DebugLogging) 453 dbgs() << "Running pass: " << Passes[Idx]->name() << " on " 454 << IR.getName() << "\n"; 455 456 PreservedAnalyses PassPA = Passes[Idx]->run(IR, AM, ExtraArgs...); 457 458 // Update the analysis manager as each pass runs and potentially 459 // invalidates analyses. 460 AM.invalidate(IR, PassPA); 461 462 // Finally, intersect the preserved analyses to compute the aggregate 463 // preserved set for this pass manager. 464 PA.intersect(std::move(PassPA)); 465 466 // FIXME: Historically, the pass managers all called the LLVM context's 467 // yield function here. We don't have a generic way to acquire the 468 // context and it isn't yet clear what the right pattern is for yielding 469 // in the new pass manager so it is currently omitted. 470 //IR.getContext().yield(); 471 } 472 473 // Invalidation was handled after each pass in the above loop for the 474 // current unit of IR. Therefore, the remaining analysis results in the 475 // AnalysisManager are preserved. We mark this with a set so that we don't 476 // need to inspect each one individually. 477 PA.preserveSet<AllAnalysesOn<IRUnitT>>(); 478 479 if (DebugLogging) 480 dbgs() << "Finished " << getTypeName<IRUnitT>() << " pass manager run.\n"; 481 482 return PA; 483 } 484 addPass(PassT Pass)485 template <typename PassT> void addPass(PassT Pass) { 486 using PassModelT = 487 detail::PassModel<IRUnitT, PassT, PreservedAnalyses, AnalysisManagerT, 488 ExtraArgTs...>; 489 490 Passes.emplace_back(new PassModelT(std::move(Pass))); 491 } 492 493 private: 494 using PassConceptT = 495 detail::PassConcept<IRUnitT, AnalysisManagerT, ExtraArgTs...>; 496 497 std::vector<std::unique_ptr<PassConceptT>> Passes; 498 499 /// Flag indicating whether we should do debug logging. 500 bool DebugLogging; 501 }; 502 503 extern template class PassManager<Module>; 504 505 /// Convenience typedef for a pass manager over modules. 506 using ModulePassManager = PassManager<Module>; 507 508 extern template class PassManager<Function>; 509 510 /// Convenience typedef for a pass manager over functions. 511 using FunctionPassManager = PassManager<Function>; 512 513 /// A container for analyses that lazily runs them and caches their 514 /// results. 515 /// 516 /// This class can manage analyses for any IR unit where the address of the IR 517 /// unit sufficies as its identity. 518 template <typename IRUnitT, typename... ExtraArgTs> class AnalysisManager { 519 public: 520 class Invalidator; 521 522 private: 523 // Now that we've defined our invalidator, we can define the concept types. 524 using ResultConceptT = 525 detail::AnalysisResultConcept<IRUnitT, PreservedAnalyses, Invalidator>; 526 using PassConceptT = 527 detail::AnalysisPassConcept<IRUnitT, PreservedAnalyses, Invalidator, 528 ExtraArgTs...>; 529 530 /// List of analysis pass IDs and associated concept pointers. 531 /// 532 /// Requires iterators to be valid across appending new entries and arbitrary 533 /// erases. Provides the analysis ID to enable finding iterators to a given 534 /// entry in maps below, and provides the storage for the actual result 535 /// concept. 536 using AnalysisResultListT = 537 std::list<std::pair<AnalysisKey *, std::unique_ptr<ResultConceptT>>>; 538 539 /// Map type from IRUnitT pointer to our custom list type. 540 using AnalysisResultListMapT = DenseMap<IRUnitT *, AnalysisResultListT>; 541 542 /// Map type from a pair of analysis ID and IRUnitT pointer to an 543 /// iterator into a particular result list (which is where the actual analysis 544 /// result is stored). 545 using AnalysisResultMapT = 546 DenseMap<std::pair<AnalysisKey *, IRUnitT *>, 547 typename AnalysisResultListT::iterator>; 548 549 public: 550 /// API to communicate dependencies between analyses during invalidation. 551 /// 552 /// When an analysis result embeds handles to other analysis results, it 553 /// needs to be invalidated both when its own information isn't preserved and 554 /// when any of its embedded analysis results end up invalidated. We pass an 555 /// \c Invalidator object as an argument to \c invalidate() in order to let 556 /// the analysis results themselves define the dependency graph on the fly. 557 /// This lets us avoid building building an explicit representation of the 558 /// dependencies between analysis results. 559 class Invalidator { 560 public: 561 /// Trigger the invalidation of some other analysis pass if not already 562 /// handled and return whether it was in fact invalidated. 563 /// 564 /// This is expected to be called from within a given analysis result's \c 565 /// invalidate method to trigger a depth-first walk of all inter-analysis 566 /// dependencies. The same \p IR unit and \p PA passed to that result's \c 567 /// invalidate method should in turn be provided to this routine. 568 /// 569 /// The first time this is called for a given analysis pass, it will call 570 /// the corresponding result's \c invalidate method. Subsequent calls will 571 /// use a cache of the results of that initial call. It is an error to form 572 /// cyclic dependencies between analysis results. 573 /// 574 /// This returns true if the given analysis's result is invalid. Any 575 /// dependecies on it will become invalid as a result. 576 template <typename PassT> invalidate(IRUnitT & IR,const PreservedAnalyses & PA)577 bool invalidate(IRUnitT &IR, const PreservedAnalyses &PA) { 578 using ResultModelT = 579 detail::AnalysisResultModel<IRUnitT, PassT, typename PassT::Result, 580 PreservedAnalyses, Invalidator>; 581 582 return invalidateImpl<ResultModelT>(PassT::ID(), IR, PA); 583 } 584 585 /// A type-erased variant of the above invalidate method with the same core 586 /// API other than passing an analysis ID rather than an analysis type 587 /// parameter. 588 /// 589 /// This is sadly less efficient than the above routine, which leverages 590 /// the type parameter to avoid the type erasure overhead. invalidate(AnalysisKey * ID,IRUnitT & IR,const PreservedAnalyses & PA)591 bool invalidate(AnalysisKey *ID, IRUnitT &IR, const PreservedAnalyses &PA) { 592 return invalidateImpl<>(ID, IR, PA); 593 } 594 595 private: 596 friend class AnalysisManager; 597 598 template <typename ResultT = ResultConceptT> invalidateImpl(AnalysisKey * ID,IRUnitT & IR,const PreservedAnalyses & PA)599 bool invalidateImpl(AnalysisKey *ID, IRUnitT &IR, 600 const PreservedAnalyses &PA) { 601 // If we've already visited this pass, return true if it was invalidated 602 // and false otherwise. 603 auto IMapI = IsResultInvalidated.find(ID); 604 if (IMapI != IsResultInvalidated.end()) 605 return IMapI->second; 606 607 // Otherwise look up the result object. 608 auto RI = Results.find({ID, &IR}); 609 assert(RI != Results.end() && 610 "Trying to invalidate a dependent result that isn't in the " 611 "manager's cache is always an error, likely due to a stale result " 612 "handle!"); 613 614 auto &Result = static_cast<ResultT &>(*RI->second->second); 615 616 // Insert into the map whether the result should be invalidated and return 617 // that. Note that we cannot reuse IMapI and must do a fresh insert here, 618 // as calling invalidate could (recursively) insert things into the map, 619 // making any iterator or reference invalid. 620 bool Inserted; 621 std::tie(IMapI, Inserted) = 622 IsResultInvalidated.insert({ID, Result.invalidate(IR, PA, *this)}); 623 (void)Inserted; 624 assert(Inserted && "Should not have already inserted this ID, likely " 625 "indicates a dependency cycle!"); 626 return IMapI->second; 627 } 628 Invalidator(SmallDenseMap<AnalysisKey *,bool,8> & IsResultInvalidated,const AnalysisResultMapT & Results)629 Invalidator(SmallDenseMap<AnalysisKey *, bool, 8> &IsResultInvalidated, 630 const AnalysisResultMapT &Results) 631 : IsResultInvalidated(IsResultInvalidated), Results(Results) {} 632 633 SmallDenseMap<AnalysisKey *, bool, 8> &IsResultInvalidated; 634 const AnalysisResultMapT &Results; 635 }; 636 637 /// Construct an empty analysis manager. 638 /// 639 /// If \p DebugLogging is true, we'll log our progress to llvm::dbgs(). DebugLogging(DebugLogging)640 AnalysisManager(bool DebugLogging = false) : DebugLogging(DebugLogging) {} 641 AnalysisManager(AnalysisManager &&) = default; 642 AnalysisManager &operator=(AnalysisManager &&) = default; 643 644 /// Returns true if the analysis manager has an empty results cache. empty()645 bool empty() const { 646 assert(AnalysisResults.empty() == AnalysisResultLists.empty() && 647 "The storage and index of analysis results disagree on how many " 648 "there are!"); 649 return AnalysisResults.empty(); 650 } 651 652 /// Clear any cached analysis results for a single unit of IR. 653 /// 654 /// This doesn't invalidate, but instead simply deletes, the relevant results. 655 /// It is useful when the IR is being removed and we want to clear out all the 656 /// memory pinned for it. clear(IRUnitT & IR,llvm::StringRef Name)657 void clear(IRUnitT &IR, llvm::StringRef Name) { 658 if (DebugLogging) 659 dbgs() << "Clearing all analysis results for: " << Name << "\n"; 660 661 auto ResultsListI = AnalysisResultLists.find(&IR); 662 if (ResultsListI == AnalysisResultLists.end()) 663 return; 664 // Delete the map entries that point into the results list. 665 for (auto &IDAndResult : ResultsListI->second) 666 AnalysisResults.erase({IDAndResult.first, &IR}); 667 668 // And actually destroy and erase the results associated with this IR. 669 AnalysisResultLists.erase(ResultsListI); 670 } 671 672 /// Clear all analysis results cached by this AnalysisManager. 673 /// 674 /// Like \c clear(IRUnitT&), this doesn't invalidate the results; it simply 675 /// deletes them. This lets you clean up the AnalysisManager when the set of 676 /// IR units itself has potentially changed, and thus we can't even look up a 677 /// a result and invalidate/clear it directly. clear()678 void clear() { 679 AnalysisResults.clear(); 680 AnalysisResultLists.clear(); 681 } 682 683 /// Get the result of an analysis pass for a given IR unit. 684 /// 685 /// Runs the analysis if a cached result is not available. 686 template <typename PassT> getResult(IRUnitT & IR,ExtraArgTs...ExtraArgs)687 typename PassT::Result &getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs) { 688 assert(AnalysisPasses.count(PassT::ID()) && 689 "This analysis pass was not registered prior to being queried"); 690 ResultConceptT &ResultConcept = 691 getResultImpl(PassT::ID(), IR, ExtraArgs...); 692 693 using ResultModelT = 694 detail::AnalysisResultModel<IRUnitT, PassT, typename PassT::Result, 695 PreservedAnalyses, Invalidator>; 696 697 return static_cast<ResultModelT &>(ResultConcept).Result; 698 } 699 700 /// Get the cached result of an analysis pass for a given IR unit. 701 /// 702 /// This method never runs the analysis. 703 /// 704 /// \returns null if there is no cached result. 705 template <typename PassT> getCachedResult(IRUnitT & IR)706 typename PassT::Result *getCachedResult(IRUnitT &IR) const { 707 assert(AnalysisPasses.count(PassT::ID()) && 708 "This analysis pass was not registered prior to being queried"); 709 710 ResultConceptT *ResultConcept = getCachedResultImpl(PassT::ID(), IR); 711 if (!ResultConcept) 712 return nullptr; 713 714 using ResultModelT = 715 detail::AnalysisResultModel<IRUnitT, PassT, typename PassT::Result, 716 PreservedAnalyses, Invalidator>; 717 718 return &static_cast<ResultModelT *>(ResultConcept)->Result; 719 } 720 721 /// Register an analysis pass with the manager. 722 /// 723 /// The parameter is a callable whose result is an analysis pass. This allows 724 /// passing in a lambda to construct the analysis. 725 /// 726 /// The analysis type to register is the type returned by calling the \c 727 /// PassBuilder argument. If that type has already been registered, then the 728 /// argument will not be called and this function will return false. 729 /// Otherwise, we register the analysis returned by calling \c PassBuilder(), 730 /// and this function returns true. 731 /// 732 /// (Note: Although the return value of this function indicates whether or not 733 /// an analysis was previously registered, there intentionally isn't a way to 734 /// query this directly. Instead, you should just register all the analyses 735 /// you might want and let this class run them lazily. This idiom lets us 736 /// minimize the number of times we have to look up analyses in our 737 /// hashtable.) 738 template <typename PassBuilderT> registerPass(PassBuilderT && PassBuilder)739 bool registerPass(PassBuilderT &&PassBuilder) { 740 using PassT = decltype(PassBuilder()); 741 using PassModelT = 742 detail::AnalysisPassModel<IRUnitT, PassT, PreservedAnalyses, 743 Invalidator, ExtraArgTs...>; 744 745 auto &PassPtr = AnalysisPasses[PassT::ID()]; 746 if (PassPtr) 747 // Already registered this pass type! 748 return false; 749 750 // Construct a new model around the instance returned by the builder. 751 PassPtr.reset(new PassModelT(PassBuilder())); 752 return true; 753 } 754 755 /// Invalidate a specific analysis pass for an IR module. 756 /// 757 /// Note that the analysis result can disregard invalidation, if it determines 758 /// it is in fact still valid. invalidate(IRUnitT & IR)759 template <typename PassT> void invalidate(IRUnitT &IR) { 760 assert(AnalysisPasses.count(PassT::ID()) && 761 "This analysis pass was not registered prior to being invalidated"); 762 invalidateImpl(PassT::ID(), IR); 763 } 764 765 /// Invalidate cached analyses for an IR unit. 766 /// 767 /// Walk through all of the analyses pertaining to this unit of IR and 768 /// invalidate them, unless they are preserved by the PreservedAnalyses set. invalidate(IRUnitT & IR,const PreservedAnalyses & PA)769 void invalidate(IRUnitT &IR, const PreservedAnalyses &PA) { 770 // We're done if all analyses on this IR unit are preserved. 771 if (PA.allAnalysesInSetPreserved<AllAnalysesOn<IRUnitT>>()) 772 return; 773 774 if (DebugLogging) 775 dbgs() << "Invalidating all non-preserved analyses for: " << IR.getName() 776 << "\n"; 777 778 // Track whether each analysis's result is invalidated in 779 // IsResultInvalidated. 780 SmallDenseMap<AnalysisKey *, bool, 8> IsResultInvalidated; 781 Invalidator Inv(IsResultInvalidated, AnalysisResults); 782 AnalysisResultListT &ResultsList = AnalysisResultLists[&IR]; 783 for (auto &AnalysisResultPair : ResultsList) { 784 // This is basically the same thing as Invalidator::invalidate, but we 785 // can't call it here because we're operating on the type-erased result. 786 // Moreover if we instead called invalidate() directly, it would do an 787 // unnecessary look up in ResultsList. 788 AnalysisKey *ID = AnalysisResultPair.first; 789 auto &Result = *AnalysisResultPair.second; 790 791 auto IMapI = IsResultInvalidated.find(ID); 792 if (IMapI != IsResultInvalidated.end()) 793 // This result was already handled via the Invalidator. 794 continue; 795 796 // Try to invalidate the result, giving it the Invalidator so it can 797 // recursively query for any dependencies it has and record the result. 798 // Note that we cannot reuse 'IMapI' here or pre-insert the ID, as 799 // Result.invalidate may insert things into the map, invalidating our 800 // iterator. 801 bool Inserted = 802 IsResultInvalidated.insert({ID, Result.invalidate(IR, PA, Inv)}) 803 .second; 804 (void)Inserted; 805 assert(Inserted && "Should never have already inserted this ID, likely " 806 "indicates a cycle!"); 807 } 808 809 // Now erase the results that were marked above as invalidated. 810 if (!IsResultInvalidated.empty()) { 811 for (auto I = ResultsList.begin(), E = ResultsList.end(); I != E;) { 812 AnalysisKey *ID = I->first; 813 if (!IsResultInvalidated.lookup(ID)) { 814 ++I; 815 continue; 816 } 817 818 if (DebugLogging) 819 dbgs() << "Invalidating analysis: " << this->lookUpPass(ID).name() 820 << " on " << IR.getName() << "\n"; 821 822 I = ResultsList.erase(I); 823 AnalysisResults.erase({ID, &IR}); 824 } 825 } 826 827 if (ResultsList.empty()) 828 AnalysisResultLists.erase(&IR); 829 } 830 831 private: 832 /// Look up a registered analysis pass. lookUpPass(AnalysisKey * ID)833 PassConceptT &lookUpPass(AnalysisKey *ID) { 834 typename AnalysisPassMapT::iterator PI = AnalysisPasses.find(ID); 835 assert(PI != AnalysisPasses.end() && 836 "Analysis passes must be registered prior to being queried!"); 837 return *PI->second; 838 } 839 840 /// Look up a registered analysis pass. lookUpPass(AnalysisKey * ID)841 const PassConceptT &lookUpPass(AnalysisKey *ID) const { 842 typename AnalysisPassMapT::const_iterator PI = AnalysisPasses.find(ID); 843 assert(PI != AnalysisPasses.end() && 844 "Analysis passes must be registered prior to being queried!"); 845 return *PI->second; 846 } 847 848 /// Get an analysis result, running the pass if necessary. getResultImpl(AnalysisKey * ID,IRUnitT & IR,ExtraArgTs...ExtraArgs)849 ResultConceptT &getResultImpl(AnalysisKey *ID, IRUnitT &IR, 850 ExtraArgTs... ExtraArgs) { 851 typename AnalysisResultMapT::iterator RI; 852 bool Inserted; 853 std::tie(RI, Inserted) = AnalysisResults.insert(std::make_pair( 854 std::make_pair(ID, &IR), typename AnalysisResultListT::iterator())); 855 856 // If we don't have a cached result for this function, look up the pass and 857 // run it to produce a result, which we then add to the cache. 858 if (Inserted) { 859 auto &P = this->lookUpPass(ID); 860 if (DebugLogging) 861 dbgs() << "Running analysis: " << P.name() << " on " << IR.getName() 862 << "\n"; 863 AnalysisResultListT &ResultList = AnalysisResultLists[&IR]; 864 ResultList.emplace_back(ID, P.run(IR, *this, ExtraArgs...)); 865 866 // P.run may have inserted elements into AnalysisResults and invalidated 867 // RI. 868 RI = AnalysisResults.find({ID, &IR}); 869 assert(RI != AnalysisResults.end() && "we just inserted it!"); 870 871 RI->second = std::prev(ResultList.end()); 872 } 873 874 return *RI->second->second; 875 } 876 877 /// Get a cached analysis result or return null. getCachedResultImpl(AnalysisKey * ID,IRUnitT & IR)878 ResultConceptT *getCachedResultImpl(AnalysisKey *ID, IRUnitT &IR) const { 879 typename AnalysisResultMapT::const_iterator RI = 880 AnalysisResults.find({ID, &IR}); 881 return RI == AnalysisResults.end() ? nullptr : &*RI->second->second; 882 } 883 884 /// Invalidate a function pass result. invalidateImpl(AnalysisKey * ID,IRUnitT & IR)885 void invalidateImpl(AnalysisKey *ID, IRUnitT &IR) { 886 typename AnalysisResultMapT::iterator RI = 887 AnalysisResults.find({ID, &IR}); 888 if (RI == AnalysisResults.end()) 889 return; 890 891 if (DebugLogging) 892 dbgs() << "Invalidating analysis: " << this->lookUpPass(ID).name() 893 << " on " << IR.getName() << "\n"; 894 AnalysisResultLists[&IR].erase(RI->second); 895 AnalysisResults.erase(RI); 896 } 897 898 /// Map type from module analysis pass ID to pass concept pointer. 899 using AnalysisPassMapT = 900 DenseMap<AnalysisKey *, std::unique_ptr<PassConceptT>>; 901 902 /// Collection of module analysis passes, indexed by ID. 903 AnalysisPassMapT AnalysisPasses; 904 905 /// Map from function to a list of function analysis results. 906 /// 907 /// Provides linear time removal of all analysis results for a function and 908 /// the ultimate storage for a particular cached analysis result. 909 AnalysisResultListMapT AnalysisResultLists; 910 911 /// Map from an analysis ID and function to a particular cached 912 /// analysis result. 913 AnalysisResultMapT AnalysisResults; 914 915 /// Indicates whether we log to \c llvm::dbgs(). 916 bool DebugLogging; 917 }; 918 919 extern template class AnalysisManager<Module>; 920 921 /// Convenience typedef for the Module analysis manager. 922 using ModuleAnalysisManager = AnalysisManager<Module>; 923 924 extern template class AnalysisManager<Function>; 925 926 /// Convenience typedef for the Function analysis manager. 927 using FunctionAnalysisManager = AnalysisManager<Function>; 928 929 /// An analysis over an "outer" IR unit that provides access to an 930 /// analysis manager over an "inner" IR unit. The inner unit must be contained 931 /// in the outer unit. 932 /// 933 /// Fore example, InnerAnalysisManagerProxy<FunctionAnalysisManager, Module> is 934 /// an analysis over Modules (the "outer" unit) that provides access to a 935 /// Function analysis manager. The FunctionAnalysisManager is the "inner" 936 /// manager being proxied, and Functions are the "inner" unit. The inner/outer 937 /// relationship is valid because each Function is contained in one Module. 938 /// 939 /// If you're (transitively) within a pass manager for an IR unit U that 940 /// contains IR unit V, you should never use an analysis manager over V, except 941 /// via one of these proxies. 942 /// 943 /// Note that the proxy's result is a move-only RAII object. The validity of 944 /// the analyses in the inner analysis manager is tied to its lifetime. 945 template <typename AnalysisManagerT, typename IRUnitT, typename... ExtraArgTs> 946 class InnerAnalysisManagerProxy 947 : public AnalysisInfoMixin< 948 InnerAnalysisManagerProxy<AnalysisManagerT, IRUnitT>> { 949 public: 950 class Result { 951 public: Result(AnalysisManagerT & InnerAM)952 explicit Result(AnalysisManagerT &InnerAM) : InnerAM(&InnerAM) {} 953 Result(Result && Arg)954 Result(Result &&Arg) : InnerAM(std::move(Arg.InnerAM)) { 955 // We have to null out the analysis manager in the moved-from state 956 // because we are taking ownership of the responsibilty to clear the 957 // analysis state. 958 Arg.InnerAM = nullptr; 959 } 960 ~Result()961 ~Result() { 962 // InnerAM is cleared in a moved from state where there is nothing to do. 963 if (!InnerAM) 964 return; 965 966 // Clear out the analysis manager if we're being destroyed -- it means we 967 // didn't even see an invalidate call when we got invalidated. 968 InnerAM->clear(); 969 } 970 971 Result &operator=(Result &&RHS) { 972 InnerAM = RHS.InnerAM; 973 // We have to null out the analysis manager in the moved-from state 974 // because we are taking ownership of the responsibilty to clear the 975 // analysis state. 976 RHS.InnerAM = nullptr; 977 return *this; 978 } 979 980 /// Accessor for the analysis manager. getManager()981 AnalysisManagerT &getManager() { return *InnerAM; } 982 983 /// Handler for invalidation of the outer IR unit, \c IRUnitT. 984 /// 985 /// If the proxy analysis itself is not preserved, we assume that the set of 986 /// inner IR objects contained in IRUnit may have changed. In this case, 987 /// we have to call \c clear() on the inner analysis manager, as it may now 988 /// have stale pointers to its inner IR objects. 989 /// 990 /// Regardless of whether the proxy analysis is marked as preserved, all of 991 /// the analyses in the inner analysis manager are potentially invalidated 992 /// based on the set of preserved analyses. 993 bool invalidate( 994 IRUnitT &IR, const PreservedAnalyses &PA, 995 typename AnalysisManager<IRUnitT, ExtraArgTs...>::Invalidator &Inv); 996 997 private: 998 AnalysisManagerT *InnerAM; 999 }; 1000 InnerAnalysisManagerProxy(AnalysisManagerT & InnerAM)1001 explicit InnerAnalysisManagerProxy(AnalysisManagerT &InnerAM) 1002 : InnerAM(&InnerAM) {} 1003 1004 /// Run the analysis pass and create our proxy result object. 1005 /// 1006 /// This doesn't do any interesting work; it is primarily used to insert our 1007 /// proxy result object into the outer analysis cache so that we can proxy 1008 /// invalidation to the inner analysis manager. run(IRUnitT & IR,AnalysisManager<IRUnitT,ExtraArgTs...> & AM,ExtraArgTs...)1009 Result run(IRUnitT &IR, AnalysisManager<IRUnitT, ExtraArgTs...> &AM, 1010 ExtraArgTs...) { 1011 return Result(*InnerAM); 1012 } 1013 1014 private: 1015 friend AnalysisInfoMixin< 1016 InnerAnalysisManagerProxy<AnalysisManagerT, IRUnitT>>; 1017 1018 static AnalysisKey Key; 1019 1020 AnalysisManagerT *InnerAM; 1021 }; 1022 1023 template <typename AnalysisManagerT, typename IRUnitT, typename... ExtraArgTs> 1024 AnalysisKey 1025 InnerAnalysisManagerProxy<AnalysisManagerT, IRUnitT, ExtraArgTs...>::Key; 1026 1027 /// Provide the \c FunctionAnalysisManager to \c Module proxy. 1028 using FunctionAnalysisManagerModuleProxy = 1029 InnerAnalysisManagerProxy<FunctionAnalysisManager, Module>; 1030 1031 /// Specialization of the invalidate method for the \c 1032 /// FunctionAnalysisManagerModuleProxy's result. 1033 template <> 1034 bool FunctionAnalysisManagerModuleProxy::Result::invalidate( 1035 Module &M, const PreservedAnalyses &PA, 1036 ModuleAnalysisManager::Invalidator &Inv); 1037 1038 // Ensure the \c FunctionAnalysisManagerModuleProxy is provided as an extern 1039 // template. 1040 extern template class InnerAnalysisManagerProxy<FunctionAnalysisManager, 1041 Module>; 1042 1043 /// An analysis over an "inner" IR unit that provides access to an 1044 /// analysis manager over a "outer" IR unit. The inner unit must be contained 1045 /// in the outer unit. 1046 /// 1047 /// For example OuterAnalysisManagerProxy<ModuleAnalysisManager, Function> is an 1048 /// analysis over Functions (the "inner" unit) which provides access to a Module 1049 /// analysis manager. The ModuleAnalysisManager is the "outer" manager being 1050 /// proxied, and Modules are the "outer" IR unit. The inner/outer relationship 1051 /// is valid because each Function is contained in one Module. 1052 /// 1053 /// This proxy only exposes the const interface of the outer analysis manager, 1054 /// to indicate that you cannot cause an outer analysis to run from within an 1055 /// inner pass. Instead, you must rely on the \c getCachedResult API. 1056 /// 1057 /// This proxy doesn't manage invalidation in any way -- that is handled by the 1058 /// recursive return path of each layer of the pass manager. A consequence of 1059 /// this is the outer analyses may be stale. We invalidate the outer analyses 1060 /// only when we're done running passes over the inner IR units. 1061 template <typename AnalysisManagerT, typename IRUnitT, typename... ExtraArgTs> 1062 class OuterAnalysisManagerProxy 1063 : public AnalysisInfoMixin< 1064 OuterAnalysisManagerProxy<AnalysisManagerT, IRUnitT, ExtraArgTs...>> { 1065 public: 1066 /// Result proxy object for \c OuterAnalysisManagerProxy. 1067 class Result { 1068 public: Result(const AnalysisManagerT & AM)1069 explicit Result(const AnalysisManagerT &AM) : AM(&AM) {} 1070 getManager()1071 const AnalysisManagerT &getManager() const { return *AM; } 1072 1073 /// When invalidation occurs, remove any registered invalidation events. invalidate(IRUnitT & IRUnit,const PreservedAnalyses & PA,typename AnalysisManager<IRUnitT,ExtraArgTs...>::Invalidator & Inv)1074 bool invalidate( 1075 IRUnitT &IRUnit, const PreservedAnalyses &PA, 1076 typename AnalysisManager<IRUnitT, ExtraArgTs...>::Invalidator &Inv) { 1077 // Loop over the set of registered outer invalidation mappings and if any 1078 // of them map to an analysis that is now invalid, clear it out. 1079 SmallVector<AnalysisKey *, 4> DeadKeys; 1080 for (auto &KeyValuePair : OuterAnalysisInvalidationMap) { 1081 AnalysisKey *OuterID = KeyValuePair.first; 1082 auto &InnerIDs = KeyValuePair.second; 1083 InnerIDs.erase(llvm::remove_if(InnerIDs, [&](AnalysisKey *InnerID) { 1084 return Inv.invalidate(InnerID, IRUnit, PA); }), 1085 InnerIDs.end()); 1086 if (InnerIDs.empty()) 1087 DeadKeys.push_back(OuterID); 1088 } 1089 1090 for (auto OuterID : DeadKeys) 1091 OuterAnalysisInvalidationMap.erase(OuterID); 1092 1093 // The proxy itself remains valid regardless of anything else. 1094 return false; 1095 } 1096 1097 /// Register a deferred invalidation event for when the outer analysis 1098 /// manager processes its invalidations. 1099 template <typename OuterAnalysisT, typename InvalidatedAnalysisT> registerOuterAnalysisInvalidation()1100 void registerOuterAnalysisInvalidation() { 1101 AnalysisKey *OuterID = OuterAnalysisT::ID(); 1102 AnalysisKey *InvalidatedID = InvalidatedAnalysisT::ID(); 1103 1104 auto &InvalidatedIDList = OuterAnalysisInvalidationMap[OuterID]; 1105 // Note, this is a linear scan. If we end up with large numbers of 1106 // analyses that all trigger invalidation on the same outer analysis, 1107 // this entire system should be changed to some other deterministic 1108 // data structure such as a `SetVector` of a pair of pointers. 1109 auto InvalidatedIt = std::find(InvalidatedIDList.begin(), 1110 InvalidatedIDList.end(), InvalidatedID); 1111 if (InvalidatedIt == InvalidatedIDList.end()) 1112 InvalidatedIDList.push_back(InvalidatedID); 1113 } 1114 1115 /// Access the map from outer analyses to deferred invalidation requiring 1116 /// analyses. 1117 const SmallDenseMap<AnalysisKey *, TinyPtrVector<AnalysisKey *>, 2> & getOuterInvalidations()1118 getOuterInvalidations() const { 1119 return OuterAnalysisInvalidationMap; 1120 } 1121 1122 private: 1123 const AnalysisManagerT *AM; 1124 1125 /// A map from an outer analysis ID to the set of this IR-unit's analyses 1126 /// which need to be invalidated. 1127 SmallDenseMap<AnalysisKey *, TinyPtrVector<AnalysisKey *>, 2> 1128 OuterAnalysisInvalidationMap; 1129 }; 1130 OuterAnalysisManagerProxy(const AnalysisManagerT & AM)1131 OuterAnalysisManagerProxy(const AnalysisManagerT &AM) : AM(&AM) {} 1132 1133 /// Run the analysis pass and create our proxy result object. 1134 /// Nothing to see here, it just forwards the \c AM reference into the 1135 /// result. run(IRUnitT &,AnalysisManager<IRUnitT,ExtraArgTs...> &,ExtraArgTs...)1136 Result run(IRUnitT &, AnalysisManager<IRUnitT, ExtraArgTs...> &, 1137 ExtraArgTs...) { 1138 return Result(*AM); 1139 } 1140 1141 private: 1142 friend AnalysisInfoMixin< 1143 OuterAnalysisManagerProxy<AnalysisManagerT, IRUnitT, ExtraArgTs...>>; 1144 1145 static AnalysisKey Key; 1146 1147 const AnalysisManagerT *AM; 1148 }; 1149 1150 template <typename AnalysisManagerT, typename IRUnitT, typename... ExtraArgTs> 1151 AnalysisKey 1152 OuterAnalysisManagerProxy<AnalysisManagerT, IRUnitT, ExtraArgTs...>::Key; 1153 1154 extern template class OuterAnalysisManagerProxy<ModuleAnalysisManager, 1155 Function>; 1156 /// Provide the \c ModuleAnalysisManager to \c Function proxy. 1157 using ModuleAnalysisManagerFunctionProxy = 1158 OuterAnalysisManagerProxy<ModuleAnalysisManager, Function>; 1159 1160 /// Trivial adaptor that maps from a module to its functions. 1161 /// 1162 /// Designed to allow composition of a FunctionPass(Manager) and 1163 /// a ModulePassManager, by running the FunctionPass(Manager) over every 1164 /// function in the module. 1165 /// 1166 /// Function passes run within this adaptor can rely on having exclusive access 1167 /// to the function they are run over. They should not read or modify any other 1168 /// functions! Other threads or systems may be manipulating other functions in 1169 /// the module, and so their state should never be relied on. 1170 /// FIXME: Make the above true for all of LLVM's actual passes, some still 1171 /// violate this principle. 1172 /// 1173 /// Function passes can also read the module containing the function, but they 1174 /// should not modify that module outside of the use lists of various globals. 1175 /// For example, a function pass is not permitted to add functions to the 1176 /// module. 1177 /// FIXME: Make the above true for all of LLVM's actual passes, some still 1178 /// violate this principle. 1179 /// 1180 /// Note that although function passes can access module analyses, module 1181 /// analyses are not invalidated while the function passes are running, so they 1182 /// may be stale. Function analyses will not be stale. 1183 template <typename FunctionPassT> 1184 class ModuleToFunctionPassAdaptor 1185 : public PassInfoMixin<ModuleToFunctionPassAdaptor<FunctionPassT>> { 1186 public: ModuleToFunctionPassAdaptor(FunctionPassT Pass)1187 explicit ModuleToFunctionPassAdaptor(FunctionPassT Pass) 1188 : Pass(std::move(Pass)) {} 1189 1190 /// Runs the function pass across every function in the module. run(Module & M,ModuleAnalysisManager & AM)1191 PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM) { 1192 FunctionAnalysisManager &FAM = 1193 AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager(); 1194 1195 PreservedAnalyses PA = PreservedAnalyses::all(); 1196 for (Function &F : M) { 1197 if (F.isDeclaration()) 1198 continue; 1199 1200 PreservedAnalyses PassPA = Pass.run(F, FAM); 1201 1202 // We know that the function pass couldn't have invalidated any other 1203 // function's analyses (that's the contract of a function pass), so 1204 // directly handle the function analysis manager's invalidation here. 1205 FAM.invalidate(F, PassPA); 1206 1207 // Then intersect the preserved set so that invalidation of module 1208 // analyses will eventually occur when the module pass completes. 1209 PA.intersect(std::move(PassPA)); 1210 } 1211 1212 // The FunctionAnalysisManagerModuleProxy is preserved because (we assume) 1213 // the function passes we ran didn't add or remove any functions. 1214 // 1215 // We also preserve all analyses on Functions, because we did all the 1216 // invalidation we needed to do above. 1217 PA.preserveSet<AllAnalysesOn<Function>>(); 1218 PA.preserve<FunctionAnalysisManagerModuleProxy>(); 1219 return PA; 1220 } 1221 1222 private: 1223 FunctionPassT Pass; 1224 }; 1225 1226 /// A function to deduce a function pass type and wrap it in the 1227 /// templated adaptor. 1228 template <typename FunctionPassT> 1229 ModuleToFunctionPassAdaptor<FunctionPassT> createModuleToFunctionPassAdaptor(FunctionPassT Pass)1230 createModuleToFunctionPassAdaptor(FunctionPassT Pass) { 1231 return ModuleToFunctionPassAdaptor<FunctionPassT>(std::move(Pass)); 1232 } 1233 1234 /// A utility pass template to force an analysis result to be available. 1235 /// 1236 /// If there are extra arguments at the pass's run level there may also be 1237 /// extra arguments to the analysis manager's \c getResult routine. We can't 1238 /// guess how to effectively map the arguments from one to the other, and so 1239 /// this specialization just ignores them. 1240 /// 1241 /// Specific patterns of run-method extra arguments and analysis manager extra 1242 /// arguments will have to be defined as appropriate specializations. 1243 template <typename AnalysisT, typename IRUnitT, 1244 typename AnalysisManagerT = AnalysisManager<IRUnitT>, 1245 typename... ExtraArgTs> 1246 struct RequireAnalysisPass 1247 : PassInfoMixin<RequireAnalysisPass<AnalysisT, IRUnitT, AnalysisManagerT, 1248 ExtraArgTs...>> { 1249 /// Run this pass over some unit of IR. 1250 /// 1251 /// This pass can be run over any unit of IR and use any analysis manager 1252 /// provided they satisfy the basic API requirements. When this pass is 1253 /// created, these methods can be instantiated to satisfy whatever the 1254 /// context requires. runRequireAnalysisPass1255 PreservedAnalyses run(IRUnitT &Arg, AnalysisManagerT &AM, 1256 ExtraArgTs &&... Args) { 1257 (void)AM.template getResult<AnalysisT>(Arg, 1258 std::forward<ExtraArgTs>(Args)...); 1259 1260 return PreservedAnalyses::all(); 1261 } 1262 }; 1263 1264 /// A no-op pass template which simply forces a specific analysis result 1265 /// to be invalidated. 1266 template <typename AnalysisT> 1267 struct InvalidateAnalysisPass 1268 : PassInfoMixin<InvalidateAnalysisPass<AnalysisT>> { 1269 /// Run this pass over some unit of IR. 1270 /// 1271 /// This pass can be run over any unit of IR and use any analysis manager, 1272 /// provided they satisfy the basic API requirements. When this pass is 1273 /// created, these methods can be instantiated to satisfy whatever the 1274 /// context requires. 1275 template <typename IRUnitT, typename AnalysisManagerT, typename... ExtraArgTs> runInvalidateAnalysisPass1276 PreservedAnalyses run(IRUnitT &Arg, AnalysisManagerT &AM, ExtraArgTs &&...) { 1277 auto PA = PreservedAnalyses::all(); 1278 PA.abandon<AnalysisT>(); 1279 return PA; 1280 } 1281 }; 1282 1283 /// A utility pass that does nothing, but preserves no analyses. 1284 /// 1285 /// Because this preserves no analyses, any analysis passes queried after this 1286 /// pass runs will recompute fresh results. 1287 struct InvalidateAllAnalysesPass : PassInfoMixin<InvalidateAllAnalysesPass> { 1288 /// Run this pass over some unit of IR. 1289 template <typename IRUnitT, typename AnalysisManagerT, typename... ExtraArgTs> runInvalidateAllAnalysesPass1290 PreservedAnalyses run(IRUnitT &, AnalysisManagerT &, ExtraArgTs &&...) { 1291 return PreservedAnalyses::none(); 1292 } 1293 }; 1294 1295 /// A utility pass template that simply runs another pass multiple times. 1296 /// 1297 /// This can be useful when debugging or testing passes. It also serves as an 1298 /// example of how to extend the pass manager in ways beyond composition. 1299 template <typename PassT> 1300 class RepeatedPass : public PassInfoMixin<RepeatedPass<PassT>> { 1301 public: RepeatedPass(int Count,PassT P)1302 RepeatedPass(int Count, PassT P) : Count(Count), P(std::move(P)) {} 1303 1304 template <typename IRUnitT, typename AnalysisManagerT, typename... Ts> run(IRUnitT & Arg,AnalysisManagerT & AM,Ts &&...Args)1305 PreservedAnalyses run(IRUnitT &Arg, AnalysisManagerT &AM, Ts &&... Args) { 1306 auto PA = PreservedAnalyses::all(); 1307 for (int i = 0; i < Count; ++i) 1308 PA.intersect(P.run(Arg, AM, std::forward<Ts>(Args)...)); 1309 return PA; 1310 } 1311 1312 private: 1313 int Count; 1314 PassT P; 1315 }; 1316 1317 template <typename PassT> createRepeatedPass(int Count,PassT P)1318 RepeatedPass<PassT> createRepeatedPass(int Count, PassT P) { 1319 return RepeatedPass<PassT>(Count, std::move(P)); 1320 } 1321 1322 } // end namespace llvm 1323 1324 #endif // LLVM_IR_PASSMANAGER_H 1325