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| 1 | +//===- llvm/IR/PassInstrumentation.h ----------------------*- 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 file defines the Pass Instrumentation classes that provide |
| 12 | +/// instrumentation points into the pass execution by PassManager. |
| 13 | +/// |
| 14 | +/// There are two main classes: |
| 15 | +/// - PassInstrumentation provides a set of instrumentation points for |
| 16 | +/// pass managers to call on. |
| 17 | +/// |
| 18 | +/// - PassInstrumentationCallbacks registers callbacks and provides access |
| 19 | +/// to them for PassInstrumentation. |
| 20 | +/// |
| 21 | +/// PassInstrumentation object is being used as a result of |
| 22 | +/// PassInstrumentationAnalysis (so it is intended to be easily copyable). |
| 23 | +/// |
| 24 | +/// Intended scheme of use for Pass Instrumentation is as follows: |
| 25 | +/// - register instrumentation callbacks in PassInstrumentationCallbacks |
| 26 | +/// instance. PassBuilder provides helper for that. |
| 27 | +/// |
| 28 | +/// - register PassInstrumentationAnalysis with all the PassManagers. |
| 29 | +/// PassBuilder handles that automatically when registering analyses. |
| 30 | +/// |
| 31 | +/// - Pass Manager requests PassInstrumentationAnalysis from analysis manager |
| 32 | +/// and gets PassInstrumentation as its result. |
| 33 | +/// |
| 34 | +/// - Pass Manager invokes PassInstrumentation entry points appropriately, |
| 35 | +/// passing StringRef identification ("name") of the pass currently being |
| 36 | +/// executed and IRUnit it works on. There can be different schemes of |
| 37 | +/// providing names in future, currently it is just a name() of the pass. |
| 38 | +/// |
| 39 | +/// - PassInstrumentation wraps address of IRUnit into llvm::Any and passes |
| 40 | +/// control to all the registered callbacks. Note that we specifically wrap |
| 41 | +/// 'const IRUnitT*' so as to avoid any accidental changes to IR in |
| 42 | +/// instrumenting callbacks. |
| 43 | +/// |
| 44 | +/// - Some instrumentation points (BeforePass) allow to control execution |
| 45 | +/// of a pass. For those callbacks returning false means pass will not be |
| 46 | +/// executed. |
| 47 | +/// |
| 48 | +/// TODO: currently there is no way for a pass to opt-out of execution control |
| 49 | +/// (e.g. become unskippable). PassManager is the only entity that determines |
| 50 | +/// how pass instrumentation affects pass execution. |
| 51 | +/// |
| 52 | +//===----------------------------------------------------------------------===// |
| 53 | + |
| 54 | +#ifndef LLVM_IR_PASSINSTRUMENTATION_H |
| 55 | +#define LLVM_IR_PASSINSTRUMENTATION_H |
| 56 | + |
| 57 | +#include "llvm/ADT/Any.h" |
| 58 | +#include "llvm/ADT/FunctionExtras.h" |
| 59 | +#include "llvm/ADT/SmallVector.h" |
| 60 | +#include "llvm/Support/TypeName.h" |
| 61 | +#include <type_traits> |
| 62 | + |
| 63 | +namespace llvm { |
| 64 | + |
| 65 | +class PreservedAnalyses; |
| 66 | + |
| 67 | +/// This class manages callbacks registration, as well as provides a way for |
| 68 | +/// PassInstrumentation to pass control to the registered callbacks. |
| 69 | +class PassInstrumentationCallbacks { |
| 70 | +public: |
| 71 | + // Before/After Pass callbacks accept IRUnits, so they need to take them |
| 72 | + // as pointers, wrapped with llvm::Any |
| 73 | + using BeforePassFunc = bool(StringRef, Any); |
| 74 | + using AfterPassFunc = void(StringRef, Any); |
| 75 | + using BeforeAnalysisFunc = void(StringRef, Any); |
| 76 | + using AfterAnalysisFunc = void(StringRef, Any); |
| 77 | + |
| 78 | +public: |
| 79 | + PassInstrumentationCallbacks() {} |
| 80 | + |
| 81 | + /// Copying PassInstrumentationCallbacks is not intended. |
| 82 | + PassInstrumentationCallbacks(const PassInstrumentationCallbacks &) = delete; |
| 83 | + void operator=(const PassInstrumentationCallbacks &) = delete; |
| 84 | + |
| 85 | + template <typename CallableT> void registerBeforePassCallback(CallableT C) { |
| 86 | + BeforePassCallbacks.emplace_back(std::move(C)); |
| 87 | + } |
| 88 | + |
| 89 | + template <typename CallableT> void registerAfterPassCallback(CallableT C) { |
| 90 | + AfterPassCallbacks.emplace_back(std::move(C)); |
| 91 | + } |
| 92 | + |
| 93 | +private: |
| 94 | + friend class PassInstrumentation; |
| 95 | + |
| 96 | + SmallVector<llvm::unique_function<BeforePassFunc>, 4> BeforePassCallbacks; |
| 97 | + SmallVector<llvm::unique_function<AfterPassFunc>, 4> AfterPassCallbacks; |
| 98 | +}; |
| 99 | + |
| 100 | +/// This class provides instrumentation entry points for the Pass Manager, |
| 101 | +/// doing calls to callbacks registered in PassInstrumentationCallbacks. |
| 102 | +class PassInstrumentation { |
| 103 | + PassInstrumentationCallbacks *Callbacks; |
| 104 | + |
| 105 | +public: |
| 106 | + /// Callbacks object is not owned by PassInstrumentation, its life-time |
| 107 | + /// should at least match the life-time of corresponding |
| 108 | + /// PassInstrumentationAnalysis (which usually is till the end of current |
| 109 | + /// compilation). |
| 110 | + PassInstrumentation(PassInstrumentationCallbacks *CB = nullptr) |
| 111 | + : Callbacks(CB) {} |
| 112 | + |
| 113 | + /// BeforePass instrumentation point - takes \p Pass instance to be executed |
| 114 | + /// and constant reference to IR it operates on. \Returns true if pass is |
| 115 | + /// allowed to be executed. |
| 116 | + template <typename IRUnitT, typename PassT> |
| 117 | + bool runBeforePass(const PassT &Pass, const IRUnitT &IR) const { |
| 118 | + if (!Callbacks) |
| 119 | + return true; |
| 120 | + |
| 121 | + bool ShouldRun = true; |
| 122 | + for (auto &C : Callbacks->BeforePassCallbacks) |
| 123 | + ShouldRun &= C(Pass.name(), llvm::Any(&IR)); |
| 124 | + return ShouldRun; |
| 125 | + } |
| 126 | + |
| 127 | + /// AfterPass instrumentation point - takes \p Pass instance that has |
| 128 | + /// just been executed and constant reference to IR it operates on. |
| 129 | + template <typename IRUnitT, typename PassT> |
| 130 | + void runAfterPass(const PassT &Pass, const IRUnitT &IR) const { |
| 131 | + if (Callbacks) |
| 132 | + for (auto &C : Callbacks->AfterPassCallbacks) |
| 133 | + C(Pass.name(), llvm::Any(&IR)); |
| 134 | + } |
| 135 | + |
| 136 | + /// Handle invalidation from the pass manager when PassInstrumentation |
| 137 | + /// is used as the result of PassInstrumentationAnalysis. |
| 138 | + /// |
| 139 | + /// On attempt to invalidate just return false. There is nothing to become |
| 140 | + /// invalid here. |
| 141 | + template <typename IRUnitT, typename... ExtraArgsT> |
| 142 | + bool invalidate(IRUnitT &, const class llvm::PreservedAnalyses &, |
| 143 | + ExtraArgsT...) { |
| 144 | + return false; |
| 145 | + } |
| 146 | +}; |
| 147 | + |
| 148 | +} // namespace llvm |
| 149 | + |
| 150 | +#endif |
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