// Copyright (c) 2018 Siegfried Pammer // // Permission is hereby granted, free of charge, to any person obtaining a copy of this // software and associated documentation files (the "Software"), to deal in the Software // without restriction, including without limitation the rights to use, copy, modify, merge, // publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons // to whom the Software is furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in all copies or // substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, // INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR // PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE // FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER // DEALINGS IN THE SOFTWARE. using System.Reflection.Metadata; namespace ICSharpCode.Decompiler.Metadata { public static class SignatureBlobComparer { public static bool EqualsMethodSignature(BlobReader a, BlobReader b, MetadataReader contextForA, MetadataReader contextForB) { return EqualsMethodSignature(ref a, ref b, contextForA, contextForB); } static bool EqualsMethodSignature(ref BlobReader a, ref BlobReader b, MetadataReader contextForA, MetadataReader contextForB) { SignatureHeader header; // compare signature headers if (a.RemainingBytes == 0 || b.RemainingBytes == 0 || (header = a.ReadSignatureHeader()) != b.ReadSignatureHeader()) return false; if (header.IsGeneric) { // read & compare generic parameter count if (!IsSameCompressedInteger(ref a, ref b, out _)) return false; } // read & compare parameter count if (!IsSameCompressedInteger(ref a, ref b, out int totalParameterCount)) return false; if (!IsSameCompressedInteger(ref a, ref b, out int typeCode)) return false; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; int i = 0; for (; i < totalParameterCount; i++) { if (!IsSameCompressedInteger(ref a, ref b, out typeCode)) return false; // varargs sentinel if (typeCode == 65) break; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; } for (; i < totalParameterCount; i++) { if (!IsSameCompressedInteger(ref a, ref b, out typeCode)) return false; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; } return true; } public static bool EqualsTypeSignature(BlobReader a, BlobReader b, MetadataReader contextForA, MetadataReader contextForB) { return EqualsTypeSignature(ref a, ref b, contextForA, contextForB); } static bool EqualsTypeSignature(ref BlobReader a, ref BlobReader b, MetadataReader contextForA, MetadataReader contextForB) { if (!IsSameCompressedInteger(ref a, ref b, out int typeCode)) return false; return TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode); } static bool IsSameCompressedInteger(ref BlobReader a, ref BlobReader b, out int value) { return a.TryReadCompressedInteger(out value) && b.TryReadCompressedInteger(out int otherValue) && value == otherValue; } static bool IsSameCompressedSignedInteger(ref BlobReader a, ref BlobReader b, out int value) { return a.TryReadCompressedSignedInteger(out value) && b.TryReadCompressedSignedInteger(out int otherValue) && value == otherValue; } static bool TypesAreEqual(ref BlobReader a, ref BlobReader b, MetadataReader contextForA, MetadataReader contextForB, int typeCode) { switch (typeCode) { case 0x1: // ELEMENT_TYPE_VOID case 0x2: // ELEMENT_TYPE_BOOLEAN case 0x3: // ELEMENT_TYPE_CHAR case 0x4: // ELEMENT_TYPE_I1 case 0x5: // ELEMENT_TYPE_U1 case 0x6: // ELEMENT_TYPE_I2 case 0x7: // ELEMENT_TYPE_U2 case 0x8: // ELEMENT_TYPE_I4 case 0x9: // ELEMENT_TYPE_U4 case 0xA: // ELEMENT_TYPE_I8 case 0xB: // ELEMENT_TYPE_U8 case 0xC: // ELEMENT_TYPE_R4 case 0xD: // ELEMENT_TYPE_R8 case 0xE: // ELEMENT_TYPE_STRING case 0x16: // ELEMENT_TYPE_TYPEDBYREF case 0x18: // ELEMENT_TYPE_I case 0x19: // ELEMENT_TYPE_U case 0x1C: // ELEMENT_TYPE_OBJECT return true; case 0xF: // ELEMENT_TYPE_PTR case 0x10: // ELEMENT_TYPE_BYREF case 0x45: // ELEMENT_TYPE_PINNED case 0x1D: // ELEMENT_TYPE_SZARRAY if (!IsSameCompressedInteger(ref a, ref b, out typeCode)) return false; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; return true; case 0x1B: // ELEMENT_TYPE_FNPTR if (!EqualsMethodSignature(ref a, ref b, contextForA, contextForB)) return false; return true; case 0x14: // ELEMENT_TYPE_ARRAY // element type if (!IsSameCompressedInteger(ref a, ref b, out typeCode)) return false; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; // rank if (!IsSameCompressedInteger(ref a, ref b, out _)) return false; // sizes if (!IsSameCompressedInteger(ref a, ref b, out int numOfSizes)) return false; for (int i = 0; i < numOfSizes; i++) { if (!IsSameCompressedInteger(ref a, ref b, out _)) return false; } // lower bounds if (!IsSameCompressedInteger(ref a, ref b, out int numOfLowerBounds)) return false; for (int i = 0; i < numOfLowerBounds; i++) { if (!IsSameCompressedSignedInteger(ref a, ref b, out _)) return false; } return true; case 0x1F: // ELEMENT_TYPE_CMOD_REQD case 0x20: // ELEMENT_TYPE_CMOD_OPT // modifier if (!TypeHandleEquals(ref a, ref b, contextForA, contextForB)) return false; // unmodified type if (!IsSameCompressedInteger(ref a, ref b, out typeCode)) return false; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; return true; case 0x15: // ELEMENT_TYPE_GENERICINST // generic type if (!IsSameCompressedInteger(ref a, ref b, out typeCode)) return false; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; if (!IsSameCompressedInteger(ref a, ref b, out int numOfArguments)) return false; for (int i = 0; i < numOfArguments; i++) { if (!IsSameCompressedInteger(ref a, ref b, out typeCode)) return false; if (!TypesAreEqual(ref a, ref b, contextForA, contextForB, typeCode)) return false; } return true; case 0x13: // ELEMENT_TYPE_VAR case 0x1E: // ELEMENT_TYPE_MVAR // index if (!IsSameCompressedInteger(ref a, ref b, out _)) return false; return true; case 0x11: // ELEMENT_TYPE_VALUETYPE case 0x12: // ELEMENT_TYPE_CLASS if (!TypeHandleEquals(ref a, ref b, contextForA, contextForB)) return false; return true; default: return false; } } static bool TypeHandleEquals(ref BlobReader a, ref BlobReader b, MetadataReader contextForA, MetadataReader contextForB) { var typeA = a.ReadTypeHandle(); var typeB = b.ReadTypeHandle(); if (typeA.IsNil || typeB.IsNil) return false; return typeA.GetFullTypeName(contextForA) == typeB.GetFullTypeName(contextForB); } } }