include/llvm/ExecutionEngine/JITLink/EHFrameSupport.h

   1 //===--------- EHFrameSupport.h - JITLink eh-frame utils --------*- C++ -*-===//
   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 // EHFrame registration support for JITLink.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORT_H
  14 #define LLVM_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORT_H
  15
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
  18 #include "llvm/ExecutionEngine/JITSymbol.h"
  19 #include "llvm/Support/Error.h"
  20
  21 namespace llvm {
  22 namespace jitlink {
  23
  24 /// Registers all FDEs in the given eh-frame section with the current process.
  25 Error registerEHFrameSection(const void *EHFrameSectionAddr,
  26                              size_t EHFrameSectionSize);
  27
  28 /// Deregisters all FDEs in the given eh-frame section with the current process.
  29 Error deregisterEHFrameSection(const void *EHFrameSectionAddr,
  30                                size_t EHFrameSectionSize);
  31
  32 /// Supports registration/deregistration of EH-frames in a target process.
  33 class EHFrameRegistrar {
  34 public:
  35   virtual ~EHFrameRegistrar();
  36   virtual Error registerEHFrames(JITTargetAddress EHFrameSectionAddr,
  37                                  size_t EHFrameSectionSize) = 0;
  38   virtual Error deregisterEHFrames(JITTargetAddress EHFrameSectionAddr,
  39                                    size_t EHFrameSectionSize) = 0;
  40 };
  41
  42 /// Registers / Deregisters EH-frames in the current process.
  43 class InProcessEHFrameRegistrar final : public EHFrameRegistrar {
  44 public:
  45   /// Get a reference to the InProcessEHFrameRegistrar singleton.
  46   static InProcessEHFrameRegistrar &getInstance();
  47
  48   InProcessEHFrameRegistrar(const InProcessEHFrameRegistrar &) = delete;
  49   InProcessEHFrameRegistrar &
  50   operator=(const InProcessEHFrameRegistrar &) = delete;
  51
  52   InProcessEHFrameRegistrar(InProcessEHFrameRegistrar &&) = delete;
  53   InProcessEHFrameRegistrar &operator=(InProcessEHFrameRegistrar &&) = delete;
  54
  55   Error registerEHFrames(JITTargetAddress EHFrameSectionAddr,
  56                          size_t EHFrameSectionSize) override {
  57     return registerEHFrameSection(
  58         jitTargetAddressToPointer<void *>(EHFrameSectionAddr),
  59         EHFrameSectionSize);
  60   }
  61
  62   Error deregisterEHFrames(JITTargetAddress EHFrameSectionAddr,
  63                            size_t EHFrameSectionSize) override {
  64     return deregisterEHFrameSection(
  65         jitTargetAddressToPointer<void *>(EHFrameSectionAddr),
  66         EHFrameSectionSize);
  67   }
  68
  69 private:
  70   InProcessEHFrameRegistrar();
  71 };
  72
  73 using StoreFrameRangeFunction =
  74   std::function<void(JITTargetAddress EHFrameSectionAddr,
  75                      size_t EHFrameSectionSize)>;
  76
  77 /// Creates a pass that records the address and size of the EH frame section.
  78 /// If no eh-frame section is found then the address and size will both be given
  79 /// as zero.
  80 ///
  81 /// Authors of JITLinkContexts can use this function to register a post-fixup
  82 /// pass that records the range of the eh-frame section. This range can
  83 /// be used after finalization to register and deregister the frame.
  84 LinkGraphPassFunction
  85 createEHFrameRecorderPass(const Triple &TT,
  86                           StoreFrameRangeFunction StoreFrameRange);
  87
  88 } // end namespace jitlink
  89 } // end namespace llvm
  90
  91 #endif // LLVM_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORT_H