llvm-project/clang-tools-extra/clang-tidy/performance/InefficientStringConcatenationCheck.cpp
Alexander Kornienko ab2d3ce47d [clang-tidy] Applied clang-tidy fixes. NFC
Applied fixes enabled by the LLVM's .clang-tidy configs. Reverted files where
fixes introduced compile errors:
  clang-tools-extra/clang-tidy/hicpp/NoAssemblerCheck.cpp
  clang-tools-extra/clang-tidy/misc/ThrowByValueCatchByReferenceCheck.cpp

$ clang-tools-extra/clang-tidy/tool/run-clang-tidy.py -fix clang-tools-extra/clang-tidy/
Enabled checks:
    llvm-else-after-return
    llvm-header-guard
    llvm-include-order
    llvm-namespace-comment
    llvm-prefer-isa-or-dyn-cast-in-conditionals
    llvm-prefer-register-over-unsigned
    llvm-qualified-auto
    llvm-twine-local
    misc-definitions-in-headers
    misc-misplaced-const
    misc-new-delete-overloads
    misc-no-recursion
    misc-non-copyable-objects
    misc-redundant-expression
    misc-static-assert
    misc-throw-by-value-catch-by-reference
    misc-unconventional-assign-operator
    misc-uniqueptr-reset-release
    misc-unused-alias-decls
    misc-unused-using-decls
    readability-identifier-naming

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D95614
2021-01-29 01:01:19 +01:00

85 lines
3.1 KiB
C++

//===--- InefficientStringConcatenationCheck.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 "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.getLocalOrGlobal("StrictMode", false)) {}
void InefficientStringConcatenationCheck::registerMatchers(
MatchFinder *Finder) {
const auto BasicStringType =
hasType(qualType(hasUnqualifiedDesugaredType(recordType(
hasDeclaration(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 char *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