1 //===--- EnumSizeCheck.cpp - clang-tidy -----------------------------------===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
30 const std::uint64_t Max8 = std::numeric_limits<std::int8_t>::max();
33 const std::uint64_t Max16 = std::numeric_limits<std::int16_t>::max();
36 const std::uint64_t Max32 = std::numeric_limits<std::int32_t>::max();
39 getNewType(std::size_t Size, std::uint64_t Min, std::uint64_t Max) noexcept {  in getNewType()  argument
41     if (Min <= Min8 && Max <= Max8) {  in getNewType()
45     if (Min <= Min16 && Max <= Max16 && Size > sizeof(std::int16_t)) {  in getNewType()
49     if (Min <= Min32 && Max <= Max32 && Size > sizeof(std::int32_t)) {  in getNewType()
56   if (Max) {  in getNewType()
57     if (Max <= std::numeric_limits<std::uint8_t>::max()) {  in getNewType()
61     if (Max <= std::numeric_limits<std::uint16_t>::max() &&  in getNewType()
62         Size > sizeof(std::uint16_t)) {  in getNewType()
66     if (Max <= std::numeric_limits<std::uint32_t>::max() &&  in getNewType()
67         Size > sizeof(std::uint32_t)) {  in getNewType()
96   Finder->addMatcher(  in registerMatchers()
106   const QualType BaseType = MatchedDecl->getIntegerType().getCanonicalType();  in check()
107   if (!BaseType->isIntegerType())  in check()
110   const std::uint32_t Size = Result.Context->getTypeSize(BaseType) / 8U;  in check()  local
111   if (1U == Size)  in check()
117   for (const auto &It : MatchedDecl->enumerators()) {  in check()
118     const llvm::APSInt &InitVal = It->getInitVal();  in check()
120       MaxV = std::max<std::uint64_t>(MaxV, InitVal.getZExtValue());  in check()
122       MinV = std::max<std::uint64_t>(MinV, InitVal.abs().getZExtValue());  in check()
126   auto NewType = getNewType(Size, MinV, MaxV);  in check()
127   if (!NewType.first || Size <= NewType.second)  in check()
130   diag(MatchedDecl->getLocation(),  in check()
131        "enum %0 uses a larger base type (%1, size: %2 %select{byte|bytes}5) "  in check()
133        "%select{byte|bytes}6) as the base type to reduce its size")  in check()
134       << MatchedDecl << MatchedDecl->getIntegerType() << Size << NewType.first  in check()
135       << NewType.second << (Size > 1U) << (NewType.second > 1U);  in check()