| //===--- InefficientStringConcatenationCheck.cpp - clang-tidy--------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "InefficientStringConcatenationCheck.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/ASTMatchers/ASTMatchFinder.h" |
| |
| using namespace clang::ast_matchers; |
| |
| namespace clang { |
| namespace tidy { |
| namespace performance { |
| |
| void InefficientStringConcatenationCheck::storeOptions( |
| ClangTidyOptions::OptionMap &Opts) { |
| Options.store(Opts, "StrictMode", StrictMode); |
| } |
| |
| InefficientStringConcatenationCheck::InefficientStringConcatenationCheck( |
| StringRef Name, ClangTidyContext *Context) |
| : ClangTidyCheck(Name, Context), StrictMode(Options.get("StrictMode", 0)) {} |
| |
| void InefficientStringConcatenationCheck::registerMatchers( |
| MatchFinder *Finder) { |
| if (!getLangOpts().CPlusPlus) |
| return; |
| |
| const auto BasicStringType = |
| hasType(cxxRecordDecl(hasName("::std::basic_string"))); |
| |
| const auto BasicStringPlusOperator = cxxOperatorCallExpr( |
| hasOverloadedOperatorName("+"), |
| hasAnyArgument(ignoringImpCasts(declRefExpr(BasicStringType)))); |
| |
| const auto PlusOperator = |
| cxxOperatorCallExpr( |
| hasOverloadedOperatorName("+"), |
| hasAnyArgument(ignoringImpCasts(declRefExpr(BasicStringType))), |
| hasDescendant(BasicStringPlusOperator)) |
| .bind("plusOperator"); |
| |
| const auto AssignOperator = cxxOperatorCallExpr( |
| hasOverloadedOperatorName("="), |
| hasArgument(0, declRefExpr(BasicStringType, |
| hasDeclaration(decl().bind("lhsStrT"))) |
| .bind("lhsStr")), |
| hasArgument(1, stmt(hasDescendant(declRefExpr( |
| hasDeclaration(decl(equalsBoundNode("lhsStrT"))))))), |
| hasDescendant(BasicStringPlusOperator)); |
| |
| if (StrictMode) { |
| Finder->addMatcher(cxxOperatorCallExpr(anyOf(AssignOperator, PlusOperator)), |
| this); |
| } else { |
| Finder->addMatcher( |
| cxxOperatorCallExpr(anyOf(AssignOperator, PlusOperator), |
| hasAncestor(stmt(anyOf(cxxForRangeStmt(), |
| whileStmt(), forStmt())))), |
| this); |
| } |
| } |
| |
| void InefficientStringConcatenationCheck::check( |
| const MatchFinder::MatchResult &Result) { |
| const auto *LhsStr = Result.Nodes.getNodeAs<DeclRefExpr>("lhsStr"); |
| const auto *PlusOperator = |
| Result.Nodes.getNodeAs<CXXOperatorCallExpr>("plusOperator"); |
| const auto DiagMsg = |
| "string concatenation results in allocation of unnecessary temporary " |
| "strings; consider using 'operator+=' or 'string::append()' instead"; |
| |
| if (LhsStr) |
| diag(LhsStr->getExprLoc(), DiagMsg); |
| else if (PlusOperator) |
| diag(PlusOperator->getExprLoc(), DiagMsg); |
| } |
| |
| } // namespace performance |
| } // namespace tidy |
| } // namespace clang |