forked from OSchip/llvm-project
81 lines
2.8 KiB
C++
81 lines
2.8 KiB
C++
//===- RedundantStringInitCheck.cpp - clang-tidy ----------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "RedundantStringInitCheck.h"
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#include "clang/ASTMatchers/ASTMatchers.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 readability {
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namespace {
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AST_MATCHER(StringLiteral, lengthIsZero) { return Node.getLength() == 0; }
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AST_MATCHER_P(Expr, ignoringImplicit,
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ast_matchers::internal::Matcher<Expr>, InnerMatcher) {
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return InnerMatcher.matches(*Node.IgnoreImplicit(), Finder, Builder);
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}
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} // namespace
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void RedundantStringInitCheck::registerMatchers(MatchFinder *Finder) {
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if (!getLangOpts().CPlusPlus)
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return;
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// Match string constructor.
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const auto StringConstructorExpr = expr(anyOf(
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cxxConstructExpr(argumentCountIs(1),
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hasDeclaration(cxxMethodDecl(hasName("basic_string")))),
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// If present, the second argument is the alloc object which must not
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// be present explicitly.
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cxxConstructExpr(argumentCountIs(2),
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hasDeclaration(cxxMethodDecl(hasName("basic_string"))),
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hasArgument(1, cxxDefaultArgExpr()))));
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// Match a string constructor expression with an empty string literal.
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const auto EmptyStringCtorExpr =
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cxxConstructExpr(StringConstructorExpr,
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hasArgument(0, ignoringParenImpCasts(
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stringLiteral(lengthIsZero()))));
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const auto EmptyStringCtorExprWithTemporaries =
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expr(ignoringImplicit(
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cxxConstructExpr(StringConstructorExpr,
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hasArgument(0, ignoringImplicit(EmptyStringCtorExpr)))));
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// Match a variable declaration with an empty string literal as initializer.
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// Examples:
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// string foo = "";
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// string bar("");
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Finder->addMatcher(
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namedDecl(varDecl(hasType(cxxRecordDecl(hasName("basic_string"))),
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hasInitializer(
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expr(anyOf(EmptyStringCtorExpr,
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EmptyStringCtorExprWithTemporaries))
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.bind("expr"))),
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unless(parmVarDecl()))
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.bind("decl"),
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this);
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}
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void RedundantStringInitCheck::check(const MatchFinder::MatchResult &Result) {
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const auto *CtorExpr = Result.Nodes.getNodeAs<Expr>("expr");
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const auto *Decl = Result.Nodes.getNodeAs<NamedDecl>("decl");
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diag(CtorExpr->getExprLoc(), "redundant string initialization")
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<< FixItHint::CreateReplacement(CtorExpr->getSourceRange(),
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Decl->getName());
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}
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} // namespace readability
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} // namespace tidy
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} // namespace clang
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