diff --git a/src/darwin/Framework/CHIP/MTRBaseDevice.mm b/src/darwin/Framework/CHIP/MTRBaseDevice.mm index 7725c9ab6e1f1b..e8211845e91cae 100644 --- a/src/darwin/Framework/CHIP/MTRBaseDevice.mm +++ b/src/darwin/Framework/CHIP/MTRBaseDevice.mm @@ -1437,7 +1437,7 @@ + (id)CHIPEncodeAndDecodeNSObject:(id)object uint8_t buffer[1024]; writer.Init(buffer, sizeof(buffer)); - CHIP_ERROR error = originalData.Encode(writer, chip::TLV::Tag(1)); + CHIP_ERROR error = originalData.Encode(writer, chip::TLV::CommonTag(1)); if (error != CHIP_NO_ERROR) { MTR_LOG_ERROR("Error: Data encoding failed: %s", error.AsString()); return nil; @@ -1456,8 +1456,9 @@ + (id)CHIPEncodeAndDecodeNSObject:(id)object return nil; } __auto_type tag = reader.GetTag(); - if (tag != chip::TLV::Tag(1)) { - MTR_LOG_ERROR("Error: TLV reader did not read the tag correctly: %llu", tag.mVal); + if (tag != chip::TLV::CommonTag(1)) { + MTR_LOG_ERROR("Error: TLV reader did not read the tag correctly: %x.%u", chip::TLV::ProfileIdFromTag(tag), + chip::TLV::TagNumFromTag(tag)); return nil; } MTRDataValueDictionaryDecodableType decodedData; diff --git a/src/lib/core/CHIPTLVReader.cpp b/src/lib/core/CHIPTLVReader.cpp index 9a95a42779e9dc..5d175eb35b7108 100644 --- a/src/lib/core/CHIPTLVReader.cpp +++ b/src/lib/core/CHIPTLVReader.cpp @@ -749,7 +749,7 @@ CHIP_ERROR TLVReader::VerifyElement() } else { - if (mElemTag == UnknownImplicitTag) + if (mElemTag == UnknownImplicitTag()) return CHIP_ERROR_UNKNOWN_IMPLICIT_TLV_TAG; switch (mContainerType) { @@ -806,11 +806,11 @@ Tag TLVReader::ReadTag(TLVTagControl tagControl, const uint8_t *& p) const return CommonTag(LittleEndian::Read32(p)); case TLVTagControl::ImplicitProfile_2Bytes: if (ImplicitProfileId == kProfileIdNotSpecified) - return UnknownImplicitTag; + return UnknownImplicitTag(); return ProfileTag(ImplicitProfileId, LittleEndian::Read16(p)); case TLVTagControl::ImplicitProfile_4Bytes: if (ImplicitProfileId == kProfileIdNotSpecified) - return UnknownImplicitTag; + return UnknownImplicitTag(); return ProfileTag(ImplicitProfileId, LittleEndian::Read32(p)); case TLVTagControl::FullyQualified_6Bytes: vendorId = LittleEndian::Read16(p); diff --git a/src/lib/core/CHIPTLVTags.h b/src/lib/core/CHIPTLVTags.h index 12de1d9e3ef2e1..da8f91006fae48 100644 --- a/src/lib/core/CHIPTLVTags.h +++ b/src/lib/core/CHIPTLVTags.h @@ -29,12 +29,59 @@ namespace chip { namespace TLV { -struct Tag +class Tag { - explicit constexpr Tag(uint64_t val) : mVal(val) {} - Tag() {} +public: + enum SpecialTagNumber : uint32_t + { + kContextTagMaxNum = UINT8_MAX, + kAnonymousTagNum, + kUnknownImplicitTagNum + }; + + Tag() = default; + constexpr bool operator==(const Tag & other) const { return mVal == other.mVal; } constexpr bool operator!=(const Tag & other) const { return mVal != other.mVal; } + +private: + explicit constexpr Tag(uint64_t val) : mVal(val) {} + + friend constexpr Tag ProfileTag(uint32_t profileId, uint32_t tagNum); + friend constexpr Tag ProfileTag(uint16_t vendorId, uint16_t profileNum, uint32_t tagNum); + friend constexpr Tag ContextTag(uint8_t tagNum); + friend constexpr Tag CommonTag(uint32_t tagNum); + friend constexpr Tag AnonymousTag(); + friend constexpr Tag UnknownImplicitTag(); + + // The following friend functions could be Tag class methods, but it turns out in some cases + // they may not be inlined and then passing the tag by argument/value results in smaller code + // than passing it by 'this' pointer. This can be worked around by applying 'always_inline' + // function attribute, but friend functions are likely a more portable solution. + + friend constexpr uint32_t ProfileIdFromTag(Tag tag); + friend constexpr uint16_t VendorIdFromTag(Tag tag); + friend constexpr uint16_t ProfileNumFromTag(Tag tag); + friend constexpr uint32_t TagNumFromTag(Tag tag); + + friend constexpr bool IsProfileTag(Tag tag); + friend constexpr bool IsContextTag(Tag tag); + friend constexpr bool IsSpecialTag(Tag tag); + + static constexpr uint32_t kProfileIdShift = 32; + static constexpr uint32_t kVendorIdShift = 48; + static constexpr uint32_t kProfileNumShift = 32; + static constexpr uint32_t kSpecialTagProfileId = 0xFFFFFFFF; + + // The storage of the tag value uses the following encoding: + // + // 63 47 31 + // +-------------------------------+-------------------------------+----------------------------------------------+ + // | Vendor id (bitwise-negated) | Profile num (bitwise-negated) | Tag number | + // +-------------------------------+-------------------------------+----------------------------------------------+ + // + // Vendor id and profile number are bitwise-negated in order to optimize the code size when + // using context tags, the most commonly used tags in the SDK. uint64_t mVal; }; @@ -50,20 +97,6 @@ enum TLVCommonProfiles kCommonProfileId = 0 }; -// TODO: Move to private namespace -enum TLVTagFields -{ - kProfileIdMask = 0xFFFFFFFF00000000ULL, - kProfileNumMask = 0x0000FFFF00000000ULL, - kVendorIdMask = 0xFFFF000000000000ULL, - kProfileIdShift = 32, - kVendorIdShift = 48, - kProfileNumShift = 32, - kTagNumMask = 0x00000000FFFFFFFFULL, - kSpecialTagMarker = 0xFFFFFFFF00000000ULL, - kContextTagMaxNum = UINT8_MAX -}; - // TODO: Move to private namespace enum class TLVTagControl : uint8_t { @@ -99,9 +132,9 @@ enum * @param[in] tagNum The profile-specific tag number assigned to the tag. * @return A 64-bit integer representing the tag. */ -inline constexpr Tag ProfileTag(uint32_t profileId, uint32_t tagNum) +constexpr Tag ProfileTag(uint32_t profileId, uint32_t tagNum) { - return Tag(((static_cast<uint64_t>(profileId)) << kProfileIdShift) | tagNum); + return Tag((static_cast<uint64_t>(~profileId) << Tag::kProfileIdShift) | tagNum); } /** @@ -112,21 +145,22 @@ inline constexpr Tag ProfileTag(uint32_t profileId, uint32_t tagNum) * @param[in] tagNum The profile-specific tag number assigned to the tag. * @return A 64-bit integer representing the tag. */ -inline constexpr Tag ProfileTag(uint16_t vendorId, uint16_t profileNum, uint32_t tagNum) +constexpr Tag ProfileTag(uint16_t vendorId, uint16_t profileNum, uint32_t tagNum) { - return Tag(((static_cast<uint64_t>(vendorId)) << kVendorIdShift) | ((static_cast<uint64_t>(profileNum)) << kProfileNumShift) | - tagNum); + constexpr uint32_t kVendorIdShift = Tag::kVendorIdShift - Tag::kProfileIdShift; + + return ProfileTag((static_cast<uint32_t>(vendorId) << kVendorIdShift) | profileNum, tagNum); } /** - * Generates the API representation for of context-specific TLV tag + * Generates the API representation of a context-specific TLV tag * * @param[in] tagNum The context-specific tag number assigned to the tag. * @return A 64-bit integer representing the tag. */ -inline constexpr Tag ContextTag(uint8_t tagNum) +constexpr Tag ContextTag(uint8_t tagNum) { - return Tag(kSpecialTagMarker | tagNum); + return ProfileTag(Tag::kSpecialTagProfileId, tagNum); } /** @@ -135,7 +169,7 @@ inline constexpr Tag ContextTag(uint8_t tagNum) * @param[in] tagNum The common profile tag number assigned to the tag. * @return A 64-bit integer representing the tag. */ -inline constexpr Tag CommonTag(uint32_t tagNum) +constexpr Tag CommonTag(uint32_t tagNum) { return ProfileTag(kCommonProfileId, tagNum); } @@ -143,12 +177,18 @@ inline constexpr Tag CommonTag(uint32_t tagNum) /** * A value signifying a TLV element that has no tag (i.e. an anonymous element). */ -inline constexpr Tag AnonymousTag() +constexpr Tag AnonymousTag() { - return Tag(kSpecialTagMarker | 0x00000000FFFFFFFFULL); + return ProfileTag(Tag::kSpecialTagProfileId, Tag::kAnonymousTagNum); +} + +/** + * An invalid tag that represents a TLV element decoding error due to unknown implicit profile id. + */ +constexpr Tag UnknownImplicitTag() +{ + return ProfileTag(Tag::kSpecialTagProfileId, Tag::kUnknownImplicitTagNum); } -// TODO: Move to private namespace -static constexpr Tag UnknownImplicitTag(kSpecialTagMarker | 0x00000000FFFFFFFEULL); /** * Returns the profile id from a TLV tag @@ -158,9 +198,24 @@ static constexpr Tag UnknownImplicitTag(kSpecialTagMarker | 0x00000000FFFFFFFEUL * @param[in] tag The API representation of a profile-specific TLV tag. * @return The profile id. */ -inline constexpr uint32_t ProfileIdFromTag(Tag tag) +constexpr uint32_t ProfileIdFromTag(Tag tag) +{ + return ~static_cast<uint32_t>(tag.mVal >> Tag::kProfileIdShift); +} + +/** + * Returns the vendor id from a TLV tag + * + * @note The behavior of this function is undefined if the supplied tag is not a profile-specific tag. + * + * @param[in] tag The API representation of a profile-specific TLV tag. + * @return The associated vendor id. + */ +constexpr uint16_t VendorIdFromTag(Tag tag) { - return static_cast<uint32_t>((tag.mVal & kProfileIdMask) >> kProfileIdShift); + constexpr uint32_t kVendorIdShift = Tag::kVendorIdShift - Tag::kProfileIdShift; + + return static_cast<uint16_t>(ProfileIdFromTag(tag) >> kVendorIdShift); } /** @@ -171,9 +226,9 @@ inline constexpr uint32_t ProfileIdFromTag(Tag tag) * @param[in] tag The API representation of a profile-specific TLV tag. * @return The associated profile number. */ -inline constexpr uint16_t ProfileNumFromTag(Tag tag) +constexpr uint16_t ProfileNumFromTag(Tag tag) { - return static_cast<uint16_t>((tag.mVal & kProfileNumMask) >> kProfileNumShift); + return static_cast<uint16_t>(ProfileIdFromTag(tag)); } /** @@ -187,44 +242,31 @@ inline constexpr uint16_t ProfileNumFromTag(Tag tag) * @param[in] tag The API representation of a profile-specific or context-specific TLV tag. * @return The associated tag number. */ -inline constexpr uint32_t TagNumFromTag(Tag tag) -{ - return static_cast<uint32_t>(tag.mVal & kTagNumMask); -} - -/** - * Returns the vendor id from a TLV tag - * - * @note The behavior of this function is undefined if the supplied tag is not a profile-specific tag. - * - * @param[in] tag The API representation of a profile-specific TLV tag. - * @return The associated vendor id. - */ -inline constexpr uint16_t VendorIdFromTag(Tag tag) +constexpr uint32_t TagNumFromTag(Tag tag) { - return static_cast<uint16_t>((tag.mVal & kVendorIdMask) >> kVendorIdShift); + return static_cast<uint32_t>(tag.mVal); } /** * Returns true of the supplied tag is a profile-specific tag. */ -inline constexpr bool IsProfileTag(Tag tag) +constexpr bool IsProfileTag(Tag tag) { - return (tag.mVal & kProfileIdMask) != kSpecialTagMarker; + return ProfileIdFromTag(tag) != Tag::kSpecialTagProfileId; } /** * Returns true if the supplied tag is a context-specific tag. */ -inline constexpr bool IsContextTag(Tag tag) +constexpr bool IsContextTag(Tag tag) { - return (tag.mVal & kProfileIdMask) == kSpecialTagMarker && TagNumFromTag(tag) <= kContextTagMaxNum; + return ProfileIdFromTag(tag) == Tag::kSpecialTagProfileId && TagNumFromTag(tag) <= Tag::kContextTagMaxNum; } // TODO: move to private namespace -inline constexpr bool IsSpecialTag(Tag tag) +constexpr bool IsSpecialTag(Tag tag) { - return (tag.mVal & kProfileIdMask) == kSpecialTagMarker; + return ProfileIdFromTag(tag) == Tag::kSpecialTagProfileId; } } // namespace TLV diff --git a/src/lib/core/CHIPTLVWriter.cpp b/src/lib/core/CHIPTLVWriter.cpp index 3f9743e23464f4..8a1eb7021edb66 100644 --- a/src/lib/core/CHIPTLVWriter.cpp +++ b/src/lib/core/CHIPTLVWriter.cpp @@ -631,7 +631,7 @@ CHIP_ERROR TLVWriter::WriteElementHead(TLVElementType elemType, Tag tag, uint64_ if (IsSpecialTag(tag)) { - if (tagNum <= kContextTagMaxNum) + if (tagNum <= Tag::kContextTagMaxNum) { if (mContainerType != kTLVType_Structure && mContainerType != kTLVType_List) return CHIP_ERROR_INVALID_TLV_TAG;