| //===--------- EHFrameSupport.h - JITLink eh-frame utils --------*- 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // EHFrame registration support for JITLink. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORT_H |
| #define LLVM_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORT_H |
| |
| #include "llvm/ExecutionEngine/JITLink/JITLink.h" |
| #include "llvm/ExecutionEngine/JITSymbol.h" |
| #include "llvm/Support/Error.h" |
| #include "llvm/TargetParser/Triple.h" |
| |
| namespace llvm { |
| namespace jitlink { |
| |
| /// Inspect an eh-frame CFI record. |
| class EHFrameCFIBlockInspector { |
| public: |
| /// Identify CFI record type and edges based on number and order of edges |
| /// in the given block only. This assumes that the block contains one CFI |
| /// record that has already been split out and fixed by the |
| /// DWARFRecordSplitter and EHFrameEdgeFixer passes. |
| /// |
| /// Zero or one outgoing edges: Record is CIE. If present, edge points to |
| /// personality. |
| /// |
| /// Two or three outgoing edges: Record is an FDE. First edge points to CIE, |
| /// second to PC-begin, third (if present) to LSDA. |
| /// |
| /// It is illegal to call this function on a block with four or more edges. |
| static EHFrameCFIBlockInspector FromEdgeScan(Block &B); |
| |
| /// Returns true if this frame is an FDE, false for a CIE. |
| bool isFDE() const { return CIEEdge != nullptr; } |
| |
| /// Returns true if this frame is a CIE, false for an FDE. |
| bool isCIE() const { return CIEEdge == nullptr; } |
| |
| /// If this is a CIE record, returns the Edge pointing at the personality |
| /// function, if any. |
| /// It is illegal to call this method on FDE records. |
| Edge *getPersonalityEdge() const { |
| assert(isCIE() && "CFI record is not a CIE"); |
| return PersonalityEdge; |
| } |
| |
| /// If this is an FDE record, returns the Edge pointing to the CIE. |
| /// If this is a CIE record, returns null. |
| /// |
| /// The result is not valid if any modification has been made to the block |
| /// after parsing. |
| Edge *getCIEEdge() const { return CIEEdge; } |
| |
| /// If this is an FDE record, returns the Edge pointing at the PC-begin |
| /// symbol. |
| /// If this a CIE record, returns null. |
| Edge *getPCBeginEdge() const { return PCBeginEdge; } |
| |
| /// If this is an FDE record, returns the Edge pointing at the LSDA, if any. |
| /// It is illegal to call this method on CIE records. |
| Edge *getLSDAEdge() const { |
| assert(isFDE() && "CFI record is not an FDE"); |
| return LSDAEdge; |
| } |
| |
| private: |
| EHFrameCFIBlockInspector(Edge *PersonalityEdge); |
| EHFrameCFIBlockInspector(Edge &CIEEdge, Edge &PCBeginEdge, Edge *LSDAEdge); |
| |
| Edge *CIEEdge = nullptr; |
| Edge *PCBeginEdge = nullptr; |
| union { |
| Edge *PersonalityEdge; |
| Edge *LSDAEdge; |
| }; |
| }; |
| |
| /// Supports registration/deregistration of EH-frames in a target process. |
| class EHFrameRegistrar { |
| public: |
| virtual ~EHFrameRegistrar(); |
| virtual Error registerEHFrames(orc::ExecutorAddrRange EHFrameSection) = 0; |
| virtual Error deregisterEHFrames(orc::ExecutorAddrRange EHFrameSection) = 0; |
| }; |
| |
| /// Registers / Deregisters EH-frames in the current process. |
| class InProcessEHFrameRegistrar final : public EHFrameRegistrar { |
| public: |
| Error registerEHFrames(orc::ExecutorAddrRange EHFrameSection) override; |
| |
| Error deregisterEHFrames(orc::ExecutorAddrRange EHFrameSection) override; |
| }; |
| |
| using StoreFrameRangeFunction = std::function<void( |
| orc::ExecutorAddr EHFrameSectionAddr, size_t EHFrameSectionSize)>; |
| |
| /// Creates a pass that records the address and size of the EH frame section. |
| /// If no eh-frame section is found then the address and size will both be given |
| /// as zero. |
| /// |
| /// Authors of JITLinkContexts can use this function to register a post-fixup |
| /// pass that records the range of the eh-frame section. This range can |
| /// be used after finalization to register and deregister the frame. |
| LinkGraphPassFunction |
| createEHFrameRecorderPass(const Triple &TT, |
| StoreFrameRangeFunction StoreFrameRange); |
| |
| } // end namespace jitlink |
| } // end namespace llvm |
| |
| #endif // LLVM_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORT_H |