private void DecodeStackSlots(byte[] image, Machine machine, GcInfoTypes gcInfoTypes, uint nSlots, bool isUntracked, ref int bitOffset) { // We have stack slots left and more room to predecode GcStackSlotBase spBase = (GcStackSlotBase)NativeReader.ReadBits(image, 2, ref bitOffset); int normSpOffset = NativeReader.DecodeVarLengthSigned(image, gcInfoTypes.STACK_SLOT_ENCBASE, ref bitOffset); int spOffset = gcInfoTypes.DenormalizeStackSlot(normSpOffset); GcSlotFlags flags = (GcSlotFlags)NativeReader.ReadBits(image, 2, ref bitOffset); GcSlots.Add(new GcSlot(GcSlots.Count, -1, new GcStackSlot(spOffset, spBase), flags, isUntracked)); for (int i = 1; i < nSlots; i++) { spBase = (GcStackSlotBase)NativeReader.ReadBits(image, 2, ref bitOffset); if ((uint)flags != 0) { normSpOffset = NativeReader.DecodeVarLengthSigned(image, gcInfoTypes.STACK_SLOT_ENCBASE, ref bitOffset); spOffset = gcInfoTypes.DenormalizeStackSlot(normSpOffset); flags = (GcSlotFlags)NativeReader.ReadBits(image, 2, ref bitOffset); } else { int normSpOffsetDelta = NativeReader.DecodeVarLengthSigned(image, gcInfoTypes.STACK_SLOT_DELTA_ENCBASE, ref bitOffset); normSpOffset += normSpOffsetDelta; spOffset = gcInfoTypes.DenormalizeStackSlot(normSpOffset); } GcSlots.Add(new GcSlot(GcSlots.Count, -1, new GcStackSlot(spOffset, spBase), flags, isUntracked)); } }
/// <summary> /// based on <a href="https://github.com/dotnet/runtime/blob/main/src/coreclr/vm/gcinfodecoder.cpp">GcInfoDecoder::GcInfoDecoder</a> /// </summary> public GcInfo(byte[] image, int offset, Machine machine, ushort majorVersion) { Offset = offset; _gcInfoTypes = new GcInfoTypes(machine); _machine = machine; SecurityObjectStackSlot = -1; GSCookieStackSlot = -1; PSPSymStackSlot = -1; SecurityObjectStackSlot = -1; GenericsInstContextStackSlot = -1; StackBaseRegister = 0xffffffff; SizeOfEditAndContinuePreservedArea = 0xffffffff; ReversePInvokeFrameStackSlot = -1; Version = ReadyToRunVersionToGcInfoVersion(majorVersion); int bitOffset = offset * 8; ParseHeaderFlags(image, ref bitOffset); if (Version >= MIN_GCINFO_VERSION_WITH_RETURN_KIND) // IsReturnKindAvailable { int returnKindBits = (_slimHeader) ? _gcInfoTypes.SIZE_OF_RETURN_KIND_SLIM : _gcInfoTypes.SIZE_OF_RETURN_KIND_FAT; ReturnKind = (ReturnKinds)NativeReader.ReadBits(image, returnKindBits, ref bitOffset); } CodeLength = _gcInfoTypes.DenormalizeCodeLength((int)NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.CODE_LENGTH_ENCBASE, ref bitOffset)); if (_hasGSCookie) { uint normPrologSize = NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.NORM_PROLOG_SIZE_ENCBASE, ref bitOffset) + 1; uint normEpilogSize = NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.NORM_EPILOG_SIZE_ENCBASE, ref bitOffset); ValidRangeStart = normPrologSize; ValidRangeEnd = (uint)CodeLength - normEpilogSize; } else if (_hasSecurityObject || _hasGenericsInstContext) { ValidRangeStart = NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.NORM_PROLOG_SIZE_ENCBASE, ref bitOffset) + 1; ValidRangeEnd = ValidRangeStart + 1; } if (_hasSecurityObject) { SecurityObjectStackSlot = _gcInfoTypes.DenormalizeStackSlot(NativeReader.DecodeVarLengthSigned(image, _gcInfoTypes.SECURITY_OBJECT_STACK_SLOT_ENCBASE, ref bitOffset)); } if (_hasGSCookie) { GSCookieStackSlot = _gcInfoTypes.DenormalizeStackSlot(NativeReader.DecodeVarLengthSigned(image, _gcInfoTypes.GS_COOKIE_STACK_SLOT_ENCBASE, ref bitOffset)); } if (_hasPSPSym) { PSPSymStackSlot = _gcInfoTypes.DenormalizeStackSlot(NativeReader.DecodeVarLengthSigned(image, _gcInfoTypes.PSP_SYM_STACK_SLOT_ENCBASE, ref bitOffset)); } if (_hasGenericsInstContext) { GenericsInstContextStackSlot = _gcInfoTypes.DenormalizeStackSlot(NativeReader.DecodeVarLengthSigned(image, _gcInfoTypes.GENERICS_INST_CONTEXT_STACK_SLOT_ENCBASE, ref bitOffset)); } if (_hasStackBaseRegister && !_slimHeader) { StackBaseRegister = _gcInfoTypes.DenormalizeStackBaseRegister(NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.STACK_BASE_REGISTER_ENCBASE, ref bitOffset)); } if (_hasSizeOfEditAndContinuePreservedArea) { SizeOfEditAndContinuePreservedArea = NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.SIZE_OF_EDIT_AND_CONTINUE_PRESERVED_AREA_ENCBASE, ref bitOffset); } if (_hasReversePInvokeFrame) { ReversePInvokeFrameStackSlot = NativeReader.DecodeVarLengthSigned(image, _gcInfoTypes.REVERSE_PINVOKE_FRAME_ENCBASE, ref bitOffset); } // FIXED_STACK_PARAMETER_SCRATCH_AREA (this macro is always defined in _gcInfoTypes.h) if (!_slimHeader) { SizeOfStackOutgoingAndScratchArea = _gcInfoTypes.DenormalizeSizeOfStackArea(NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.SIZE_OF_STACK_AREA_ENCBASE, ref bitOffset)); } // PARTIALLY_INTERRUPTIBLE_GC_SUPPORTED (this macro is always defined in _gcInfoTypes.h) NumSafePoints = NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.NUM_SAFE_POINTS_ENCBASE, ref bitOffset); if (!_slimHeader) { NumInterruptibleRanges = NativeReader.DecodeVarLengthUnsigned(image, _gcInfoTypes.NUM_INTERRUPTIBLE_RANGES_ENCBASE, ref bitOffset); } // PARTIALLY_INTERRUPTIBLE_GC_SUPPORTED (this macro is always defined in _gcInfoTypes.h) SafePointOffsets = EnumerateSafePoints(image, ref bitOffset); InterruptibleRanges = EnumerateInterruptibleRanges(image, _gcInfoTypes.INTERRUPTIBLE_RANGE_DELTA1_ENCBASE, _gcInfoTypes.INTERRUPTIBLE_RANGE_DELTA2_ENCBASE, ref bitOffset); SlotTable = new GcSlotTable(image, machine, _gcInfoTypes, ref bitOffset); if (SlotTable.NumSlots > 0) { if (NumSafePoints > 0) { // Partially interruptible code LiveSlotsAtSafepoints = GetLiveSlotsAtSafepoints(image, ref bitOffset); } else { // Fully interruptible code Transitions = GetTransitions(image, ref bitOffset); } } int nextByteOffset = (bitOffset + 7) >> 3; Size = nextByteOffset - offset; }