[BOLT] Factor out MCInstReference from gadget scanner (NFC) #138655
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| //===- bolt/Core/MCInstUtils.h ----------------------------------*- C++ -*-===// | ||
| // | ||
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | ||
| // See https://llvm.org/LICENSE.txt for license information. | ||
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | ||
| // | ||
| //===----------------------------------------------------------------------===// | ||
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| #ifndef BOLT_CORE_MCINSTUTILS_H | ||
| #define BOLT_CORE_MCINSTUTILS_H | ||
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| #include "bolt/Core/BinaryBasicBlock.h" | ||
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| #include <map> | ||
| #include <tuple> | ||
| #include <variant> | ||
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| namespace llvm { | ||
| namespace bolt { | ||
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| class BinaryFunction; | ||
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| /// MCInstReference represents a reference to a constant MCInst as stored either | ||
| /// in a BinaryFunction (i.e. before a CFG is created), or in a BinaryBasicBlock | ||
| /// (after a CFG is created). | ||
| class MCInstReference { | ||
| using nocfg_const_iterator = std::map<uint32_t, MCInst>::const_iterator; | ||
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| // Two cases are possible: | ||
| // * functions with CFG reconstructed - a function stores a collection of | ||
| // basic blocks, each basic block stores a contiguous vector of MCInst | ||
| // * functions without CFG - there are no basic blocks created, | ||
| // the instructions are directly stored in std::map in BinaryFunction | ||
| // | ||
| // In both cases, the direct parent of MCInst is stored together with an | ||
| // iterator pointing to the instruction. | ||
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| // Helper struct: CFG is available, the direct parent is a basic block, | ||
| // iterator's type is `MCInst *`. | ||
| struct RefInBB { | ||
| RefInBB(const BinaryBasicBlock *BB, const MCInst *Inst) | ||
| : BB(BB), It(Inst) {} | ||
| RefInBB(const RefInBB &Other) = default; | ||
| RefInBB &operator=(const RefInBB &Other) = default; | ||
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| const BinaryBasicBlock *BB; | ||
| BinaryBasicBlock::const_iterator It; | ||
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| bool operator<(const RefInBB &Other) const { | ||
|
There was a problem hiding this comment. What are expected uses for this comparison? I'm concerned about non-deterministic order of |
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| return std::tie(BB, It) < std::tie(Other.BB, Other.It); | ||
| } | ||
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| bool operator==(const RefInBB &Other) const { | ||
| return BB == Other.BB && It == Other.It; | ||
| } | ||
| }; | ||
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| // Helper struct: CFG is *not* available, the direct parent is a function, | ||
| // iterator's type is std::map<uint32_t, MCInst>::iterator (the mapped value | ||
| // is an instruction's offset). | ||
| struct RefInBF { | ||
| RefInBF(const BinaryFunction *BF, nocfg_const_iterator It) | ||
| : BF(BF), It(It) {} | ||
| RefInBF(const RefInBF &Other) = default; | ||
| RefInBF &operator=(const RefInBF &Other) = default; | ||
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| const BinaryFunction *BF; | ||
| nocfg_const_iterator It; | ||
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| bool operator<(const RefInBF &Other) const { | ||
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There was a problem hiding this comment. Similar concern regarding the |
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| return std::tie(BF, It->first) < std::tie(Other.BF, Other.It->first); | ||
| } | ||
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| bool operator==(const RefInBF &Other) const { | ||
| return BF == Other.BF && It->first == Other.It->first; | ||
| } | ||
| }; | ||
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| std::variant<RefInBB, RefInBF> Reference; | ||
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| // Utility methods to be used like this: | ||
| // | ||
| // if (auto *Ref = tryGetRefInBB()) | ||
| // return Ref->doSomething(...); | ||
| // return getRefInBF().doSomethingElse(...); | ||
| const RefInBB *tryGetRefInBB() const { | ||
| assert(std::get_if<RefInBB>(&Reference) || | ||
| std::get_if<RefInBF>(&Reference)); | ||
| return std::get_if<RefInBB>(&Reference); | ||
| } | ||
| const RefInBF &getRefInBF() const { | ||
| assert(std::get_if<RefInBF>(&Reference)); | ||
| return *std::get_if<RefInBF>(&Reference); | ||
| } | ||
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| public: | ||
| /// Constructs an empty reference. | ||
| MCInstReference() : Reference(RefInBB(nullptr, nullptr)) {} | ||
| /// Constructs a reference to the instruction inside the basic block. | ||
| MCInstReference(const BinaryBasicBlock *BB, const MCInst *Inst) | ||
| : Reference(RefInBB(BB, Inst)) { | ||
| assert(BB && Inst && "Neither BB nor Inst should be nullptr"); | ||
| } | ||
| /// Constructs a reference to the instruction inside the basic block. | ||
| MCInstReference(const BinaryBasicBlock *BB, unsigned Index) | ||
| : Reference(RefInBB(BB, &BB->getInstructionAtIndex(Index))) { | ||
| assert(BB && "Basic block should not be nullptr"); | ||
| } | ||
| /// Constructs a reference to the instruction inside the function without | ||
| /// CFG information. | ||
| MCInstReference(const BinaryFunction *BF, nocfg_const_iterator It) | ||
| : Reference(RefInBF(BF, It)) { | ||
| assert(BF && "Function should not be nullptr"); | ||
| } | ||
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| /// Locates an instruction inside a function and returns a reference. | ||
| static MCInstReference get(const MCInst *Inst, const BinaryFunction &BF); | ||
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| bool operator<(const MCInstReference &Other) const { | ||
| return Reference < Other.Reference; | ||
| } | ||
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| bool operator==(const MCInstReference &Other) const { | ||
| return Reference == Other.Reference; | ||
| } | ||
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| const MCInst &getMCInst() const { | ||
| if (auto *Ref = tryGetRefInBB()) | ||
| return *Ref->It; | ||
| return getRefInBF().It->second; | ||
| } | ||
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| operator const MCInst &() const { return getMCInst(); } | ||
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| operator bool() const { | ||
| if (auto *Ref = tryGetRefInBB()) | ||
| return Ref->BB != nullptr; | ||
| return getRefInBF().BF != nullptr; | ||
| } | ||
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| bool hasCFG() const { | ||
| return static_cast<bool>(*this) && tryGetRefInBB() != nullptr; | ||
| } | ||
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| const BinaryFunction *getFunction() const { | ||
| if (auto *Ref = tryGetRefInBB()) | ||
| return Ref->BB->getFunction(); | ||
| return getRefInBF().BF; | ||
| } | ||
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| const BinaryBasicBlock *getBasicBlock() const { | ||
| if (auto *Ref = tryGetRefInBB()) | ||
| return Ref->BB; | ||
| return nullptr; | ||
| } | ||
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| raw_ostream &print(raw_ostream &OS) const; | ||
| }; | ||
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| static inline raw_ostream &operator<<(raw_ostream &OS, | ||
| const MCInstReference &Ref) { | ||
| return Ref.print(OS); | ||
| } | ||
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| } // namespace bolt | ||
| } // namespace llvm | ||
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| #endif | ||
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nit: drop empty line.