llvm-project

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//===--- SuspiciousStringviewDataUsageCheck.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 "SuspiciousStringviewDataUsageCheck.h"
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#include "../utils/Matchers.h"
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#include "../utils/OptionsUtils.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::tidy::bugprone {
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SuspiciousStringviewDataUsageCheck::SuspiciousStringviewDataUsageCheck(
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    StringRef Name, ClangTidyContext *Context)
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    : ClangTidyCheck(Name, Context),
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      StringViewTypes(utils::options::parseStringList(Options.get(
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          "StringViewTypes", "::std::basic_string_view;::llvm::StringRef"))),
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      AllowedCallees(
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          utils::options::parseStringList(Options.get("AllowedCallees", ""))) {}
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void SuspiciousStringviewDataUsageCheck::storeOptions(
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    ClangTidyOptions::OptionMap &Opts) {
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  Options.store(Opts, "StringViewTypes",
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                utils::options::serializeStringList(StringViewTypes));
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  Options.store(Opts, "AllowedCallees",
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                utils::options::serializeStringList(AllowedCallees));
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}
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bool SuspiciousStringviewDataUsageCheck::isLanguageVersionSupported(
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    const LangOptions &LangOpts) const {
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  return LangOpts.CPlusPlus;
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}
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std::optional<TraversalKind>
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SuspiciousStringviewDataUsageCheck::getCheckTraversalKind() const {
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  return TK_AsIs;
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}
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void SuspiciousStringviewDataUsageCheck::registerMatchers(MatchFinder *Finder) {
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  auto AncestorCall = anyOf(
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      cxxConstructExpr(), callExpr(unless(cxxOperatorCallExpr())), lambdaExpr(),
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      initListExpr(
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          hasType(qualType(hasCanonicalType(hasDeclaration(recordDecl()))))));
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  auto DataMethod =
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      cxxMethodDecl(hasName("data"),
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                    ofClass(matchers::matchesAnyListedName(StringViewTypes)));
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  auto SizeCall = cxxMemberCallExpr(
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      callee(cxxMethodDecl(hasAnyName("size", "length"))),
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      on(ignoringParenImpCasts(
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          matchers::isStatementIdenticalToBoundNode("self"))));
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  auto DescendantSizeCall = expr(hasDescendant(
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      expr(SizeCall, hasAncestor(expr(AncestorCall).bind("ancestor-size")),
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           hasAncestor(expr(equalsBoundNode("parent"),
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                            equalsBoundNode("ancestor-size"))))));
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  Finder->addMatcher(
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      cxxMemberCallExpr(
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          on(ignoringParenImpCasts(expr().bind("self"))), callee(DataMethod),
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          expr().bind("data-call"),
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          hasParent(expr(anyOf(
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              invocation(
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                  expr().bind("parent"), unless(cxxOperatorCallExpr()),
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                  hasAnyArgument(
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                      ignoringParenImpCasts(equalsBoundNode("data-call"))),
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                  unless(hasAnyArgument(ignoringParenImpCasts(SizeCall))),
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                  unless(hasAnyArgument(DescendantSizeCall)),
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                  hasDeclaration(namedDecl(
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                      unless(matchers::matchesAnyListedName(AllowedCallees))))),
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              initListExpr(expr().bind("parent"),
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                           hasType(qualType(hasCanonicalType(hasDeclaration(
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                               recordDecl(unless(matchers::matchesAnyListedName(
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                                   AllowedCallees))))))),
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                           unless(DescendantSizeCall)))))),
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      this);
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}
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void SuspiciousStringviewDataUsageCheck::check(
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    const MatchFinder::MatchResult &Result) {
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  const auto *DataCallExpr =
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      Result.Nodes.getNodeAs<CXXMemberCallExpr>("data-call");
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  diag(DataCallExpr->getExprLoc(),
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       "result of a `data()` call may not be null terminated, provide size "
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       "information to the callee to prevent potential issues")
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      << DataCallExpr->getCallee()->getSourceRange();
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}
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} // namespace clang::tidy::bugprone
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