================ @@ -0,0 +1,69 @@ +//===--- UnintendedCharOstreamOutputCheck.cpp - clang-tidy ----------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "UnintendedCharOstreamOutputCheck.h" +#include "clang/AST/Type.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchers.h" + +using namespace clang::ast_matchers; + +namespace clang::tidy::bugprone { + +namespace { + +// check if the type is unsigned char or signed char +AST_MATCHER(Type, isNumericChar) { + const auto *BT = dyn_cast<BuiltinType>(&Node); + if (BT == nullptr) + return false; + const BuiltinType::Kind K = BT->getKind(); + return K == BuiltinType::UChar || K == BuiltinType::SChar; +} + +// check if the type is char +AST_MATCHER(Type, isChar) { + const auto *BT = dyn_cast<BuiltinType>(&Node); + if (BT == nullptr) + return false; + const BuiltinType::Kind K = BT->getKind(); + return K == BuiltinType::Char_U || K == BuiltinType::Char_S; +} + +} // namespace + +void UnintendedCharOstreamOutputCheck::registerMatchers(MatchFinder *Finder) { + auto BasicOstream = + cxxRecordDecl(hasName("::std::basic_ostream"), + // only basic_ostream<char, Traits> has overload operator<< + // with char / unsigned char / signed char + classTemplateSpecializationDecl( + hasTemplateArgument(0, refersToType(isChar())))); + Finder->addMatcher( + cxxOperatorCallExpr( + hasOverloadedOperatorName("<<"), + hasLHS(hasType(hasUnqualifiedDesugaredType( + recordType(hasDeclaration(cxxRecordDecl( + anyOf(BasicOstream, isDerivedFrom(BasicOstream)))))))), + hasRHS(hasType(hasUnqualifiedDesugaredType(isNumericChar())))) + .bind("x"), + this); +} + +void UnintendedCharOstreamOutputCheck::check( + const MatchFinder::MatchResult &Result) { + const auto *Call = Result.Nodes.getNodeAs<CXXOperatorCallExpr>("x"); + const Expr *Value = Call->getArg(1); + diag(Call->getOperatorLoc(), + "%0 passed to 'operator<<' outputs as character instead of integer. " + "cast to 'unsigned' to print numeric value or cast to 'char' to print " + "as character") + << Value->getType() << Value->getSourceRange(); ---------------- firewave wrote:
Given the range only suggesting `int` should be safe. Adding `unsigned` in case the underlying type would make it more clearer though. As in other cases I think it should be coding guideline agnostic and suggest the least intrusive (e.g. `std::int32_t` requires the `<cstdint>` include). But let's not start that discussion again... https://github.com/llvm/llvm-project/pull/127720 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
