85 lines
3.1 KiB
C++
85 lines
3.1 KiB
C++
//===--- InefficientStringConcatenationCheck.cpp - clang-tidy--------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "InefficientStringConcatenationCheck.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/ASTMatchers/ASTMatchFinder.h"
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using namespace clang::ast_matchers;
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namespace clang {
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namespace tidy {
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namespace performance {
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void InefficientStringConcatenationCheck::storeOptions(
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ClangTidyOptions::OptionMap &Opts) {
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Options.store(Opts, "StrictMode", StrictMode);
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}
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InefficientStringConcatenationCheck::InefficientStringConcatenationCheck(
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StringRef Name, ClangTidyContext *Context)
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: ClangTidyCheck(Name, Context),
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StrictMode(Options.getLocalOrGlobal("StrictMode", false)) {}
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void InefficientStringConcatenationCheck::registerMatchers(
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MatchFinder *Finder) {
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const auto BasicStringType =
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hasType(qualType(hasUnqualifiedDesugaredType(recordType(
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hasDeclaration(cxxRecordDecl(hasName("::std::basic_string")))))));
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const auto BasicStringPlusOperator = cxxOperatorCallExpr(
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hasOverloadedOperatorName("+"),
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hasAnyArgument(ignoringImpCasts(declRefExpr(BasicStringType))));
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const auto PlusOperator =
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cxxOperatorCallExpr(
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hasOverloadedOperatorName("+"),
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hasAnyArgument(ignoringImpCasts(declRefExpr(BasicStringType))),
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hasDescendant(BasicStringPlusOperator))
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.bind("plusOperator");
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const auto AssignOperator = cxxOperatorCallExpr(
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hasOverloadedOperatorName("="),
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hasArgument(0, declRefExpr(BasicStringType,
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hasDeclaration(decl().bind("lhsStrT")))
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.bind("lhsStr")),
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hasArgument(1, stmt(hasDescendant(declRefExpr(
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hasDeclaration(decl(equalsBoundNode("lhsStrT"))))))),
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hasDescendant(BasicStringPlusOperator));
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if (StrictMode) {
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Finder->addMatcher(cxxOperatorCallExpr(anyOf(AssignOperator, PlusOperator)),
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this);
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} else {
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Finder->addMatcher(
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cxxOperatorCallExpr(anyOf(AssignOperator, PlusOperator),
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hasAncestor(stmt(anyOf(cxxForRangeStmt(),
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whileStmt(), forStmt())))),
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this);
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}
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}
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void InefficientStringConcatenationCheck::check(
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const MatchFinder::MatchResult &Result) {
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const auto *LhsStr = Result.Nodes.getNodeAs<DeclRefExpr>("lhsStr");
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const auto *PlusOperator =
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Result.Nodes.getNodeAs<CXXOperatorCallExpr>("plusOperator");
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const char *DiagMsg =
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"string concatenation results in allocation of unnecessary temporary "
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"strings; consider using 'operator+=' or 'string::append()' instead";
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if (LhsStr)
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diag(LhsStr->getExprLoc(), DiagMsg);
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else if (PlusOperator)
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diag(PlusOperator->getExprLoc(), DiagMsg);
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}
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} // namespace performance
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} // namespace tidy
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} // namespace clang
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