void StrCatAppendCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
  	return;
  const auto StrCat = functionDecl(hasName("::absl::StrCat"));
  // The arguments of absl::StrCat are implicitly converted to AlphaNum. This 
  // matches to the arguments because of that behavior. 
  const auto AlphaNum = IgnoringTemporaries(cxxConstructExpr(
      argumentCountIs(1), hasType(cxxRecordDecl(hasName("::absl::AlphaNum"))),
      hasArgument(0, ignoringImpCasts(declRefExpr(to(equalsBoundNode("LHS")),
                                                  expr().bind("Arg0"))))));

  const auto HasAnotherReferenceToLhs =
      callExpr(hasAnyArgument(expr(hasDescendant(declRefExpr(
          to(equalsBoundNode("LHS")), unless(equalsBoundNode("Arg0")))))));

  // Now look for calls to operator= with an object on the LHS and a call to
  // StrCat on the RHS. The first argument of the StrCat call should be the same
  // as the LHS. Ignore calls from template instantiations.
  Finder->addMatcher(
      cxxOperatorCallExpr(
          unless(isInTemplateInstantiation()), hasOverloadedOperatorName("="),
          hasArgument(0, declRefExpr(to(decl().bind("LHS")))),
          hasArgument(1, IgnoringTemporaries(
                             callExpr(callee(StrCat), hasArgument(0, AlphaNum),
                                      unless(HasAnotherReferenceToLhs))
                                 .bind("Call"))))
          .bind("Op"),
      this);
}
void PassByValueCheck::registerMatchers(MatchFinder *Finder) {
  // Only register the matchers for C++; the functionality currently does not
  // provide any benefit to other languages, despite being benign.
  if (!getLangOpts().CPlusPlus)
    return;

  Finder->addMatcher(
      cxxConstructorDecl(
          forEachConstructorInitializer(
              cxxCtorInitializer(
                  // Clang builds a CXXConstructExpr only whin it knows which
                  // constructor will be called. In dependent contexts a
                  // ParenListExpr is generated instead of a CXXConstructExpr,
                  // filtering out templates automatically for us.
                  withInitializer(cxxConstructExpr(
                      has(ignoringParenImpCasts(declRefExpr(to(
                          parmVarDecl(
                              hasType(qualType(
                                  // Match only const-ref or a non-const value
                                  // parameters. Rvalues and const-values
                                  // shouldn't be modified.
                                  anyOf(constRefType(), nonConstValueType()))))
                              .bind("Param"))))),
                      hasDeclaration(cxxConstructorDecl(
                          isCopyConstructor(), unless(isDeleted()),
                          hasDeclContext(
                              cxxRecordDecl(isMoveConstructible())))))))
                  .bind("Initializer")))
          .bind("Ctor"),
      this);
}
TEST_F(StructuralEquivalenceRecordTest, Name) {
  auto t = makeDecls<CXXRecordDecl>(
      "struct A{ };",
      "struct B{ };",
      Lang_CXX,
      cxxRecordDecl(hasName("A")),
      cxxRecordDecl(hasName("B")));
  EXPECT_FALSE(testStructuralMatch(t));
}
Example #4
0
void SlicingCheck::registerMatchers(MatchFinder *Finder) {
  // When we see:
  //   class B : public A { ... };
  //   A a;
  //   B b;
  //   a = b;
  // The assignment is OK if:
  //   - the assignment operator is defined as taking a B as second parameter,
  //   or
  //   - B does not define any additional members (either variables or
  //   overrides) wrt A.
  //
  // The same holds for copy ctor calls. This also captures stuff like:
  //   void f(A a);
  //   f(b);

  //  Helpers.
  const auto OfBaseClass = ofClass(cxxRecordDecl().bind("BaseDecl"));
  const auto IsDerivedFromBaseDecl =
      cxxRecordDecl(isDerivedFrom(equalsBoundNode("BaseDecl")))
          .bind("DerivedDecl");
  const auto HasTypeDerivedFromBaseDecl =
      anyOf(hasType(IsDerivedFromBaseDecl),
            hasType(references(IsDerivedFromBaseDecl)));
  const auto IsWithinDerivedCtor =
      hasParent(cxxConstructorDecl(ofClass(equalsBoundNode("DerivedDecl"))));

  // Assignement slicing: "a = b;" and "a = std::move(b);" variants.
  const auto SlicesObjectInAssignment =
      callExpr(callee(cxxMethodDecl(anyOf(isCopyAssignmentOperator(),
                                          isMoveAssignmentOperator()),
                                    OfBaseClass)),
               hasArgument(1, HasTypeDerivedFromBaseDecl));

  // Construction slicing: "A a{b};" and "f(b);" variants. Note that in case of
  // slicing the letter will create a temporary and therefore call a ctor.
  const auto SlicesObjectInCtor = cxxConstructExpr(
      hasDeclaration(cxxConstructorDecl(
          anyOf(isCopyConstructor(), isMoveConstructor()), OfBaseClass)),
      hasArgument(0, HasTypeDerivedFromBaseDecl),
      // We need to disable matching on the call to the base copy/move
      // constructor in DerivedDecl's constructors.
      unless(IsWithinDerivedCtor));

  Finder->addMatcher(
      expr(anyOf(SlicesObjectInAssignment, SlicesObjectInCtor)).bind("Call"),
      this);
}
void UseNodiscardCheck::registerMatchers(MatchFinder *Finder) {
  // If we use ``[[nodiscard]]`` attribute, we require at least C++17. Use a
  // macro or ``__attribute__`` with pre c++17 compilers by using
  // ReplacementString option.
  if ((NoDiscardMacro == "[[nodiscard]]" && !getLangOpts().CPlusPlus17) ||
      !getLangOpts().CPlusPlus)
    return;

  auto FunctionObj =
      cxxRecordDecl(hasAnyName("::std::function", "::boost::function"));

  // Find all non-void const methods which have not already been marked to
  // warn on unused result.
  Finder->addMatcher(
      cxxMethodDecl(
          allOf(isConst(), isDefinitionOrInline(),
                unless(anyOf(
                    returns(voidType()), isNoReturn(), isOverloadedOperator(),
                    isVariadic(), hasTemplateReturnType(),
                    hasClassMutableFields(), isConversionOperator(),
                    hasAttr(clang::attr::WarnUnusedResult),
                    hasType(isInstantiationDependentType()),
                    hasAnyParameter(anyOf(
                        parmVarDecl(anyOf(hasType(FunctionObj),
                                          hasType(references(FunctionObj)))),
                        hasType(isNonConstReferenceOrPointer()),
                        hasParameterPack()))))))
          .bind("no_discard"),
      this);
}
void UseEqualsDeleteCheck::registerMatchers(MatchFinder *Finder) {
  auto PrivateSpecialFn = cxxMethodDecl(
      isPrivate(),
      anyOf(cxxConstructorDecl(anyOf(isDefaultConstructor(),
                                     isCopyConstructor(), isMoveConstructor())),
            cxxMethodDecl(
                anyOf(isCopyAssignmentOperator(), isMoveAssignmentOperator())),
            cxxDestructorDecl()));

  Finder->addMatcher(
      cxxMethodDecl(
          PrivateSpecialFn,
          unless(anyOf(hasBody(stmt()), isDefaulted(), isDeleted(),
                       ast_matchers::isTemplateInstantiation(),
                       // Ensure that all methods except private special member
                       // functions are defined.
                       hasParent(cxxRecordDecl(hasMethod(unless(
                           anyOf(PrivateSpecialFn, hasBody(stmt()), isPure(),
                                 isDefaulted(), isDeleted()))))))))
          .bind(SpecialFunction),
      this);

  Finder->addMatcher(
      cxxMethodDecl(isDeleted(), unless(isPublic())).bind(DeletedNotPublic),
      this);
}
void NonPrivateMemberVariablesInClassesCheck::registerMatchers(
    MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;

  // We can ignore structs/classes with all member variables being public.
  auto ShouldIgnoreRecord =
      allOf(boolean(IgnoreClassesWithAllMemberVariablesBeingPublic),
            unless(hasNonPublicMemberVariable()));

  // There are three visibility types: public, protected, private.
  // If we are ok with public fields, then we only want to complain about
  // protected fields, else we want to complain about all non-private fields.
  // We can ignore public member variables in structs/classes, in unions.
  auto InterestingField = fieldDecl(
      IgnorePublicMemberVariables ? isProtected() : unless(isPrivate()));

  // We only want the records that not only contain the mutable data (non-static
  // member variables), but also have some logic (non-static member functions).
  // We may optionally ignore records where all the member variables are public.
  Finder->addMatcher(cxxRecordDecl(anyOf(isStruct(), isClass()), hasMethods(),
                                   hasNonStaticMethod(),
                                   unless(ShouldIgnoreRecord),
                                   forEach(InterestingField.bind("field")))
                         .bind("record"),
                     this);
}
TEST_F(StructuralEquivalenceRecordTest, TemplateVsNonTemplate) {
  auto t = makeDecls<CXXRecordDecl>(
      "struct A { };",
      "template<class T> struct A { };",
      Lang_CXX,
      cxxRecordDecl(hasName("A")));
  EXPECT_FALSE(testStructuralMatch(t));
}
void ExceptionBaseclassCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;

  Finder->addMatcher(
      cxxThrowExpr(allOf(has(expr(unless(hasType(qualType(hasCanonicalType(
                             hasDeclaration(cxxRecordDecl(isSameOrDerivedFrom(
                                 hasName("std::exception")))))))))),
                         has(expr(unless(cxxUnresolvedConstructExpr()))),
                         eachOf(has(expr(hasType(namedDecl().bind("decl")))),
                                anything())))
          .bind("bad_throw"),
      this);
}
void UseEmplaceCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus11)
    return;

  // FIXME: Bunch of functionality that could be easily added:
  // + add handling of `push_front` for std::forward_list, std::list
  // and std::deque.
  // + add handling of `push` for std::stack, std::queue, std::priority_queue
  // + add handling of `insert` for stl associative container, but be careful
  // because this requires special treatment (it could cause performance
  // regression)
  // + match for emplace calls that should be replaced with insertion
  // + match for make_pair calls.
  auto callPushBack = cxxMemberCallExpr(
      hasDeclaration(functionDecl(hasName("push_back"))),
      on(hasType(cxxRecordDecl(hasAnyName("std::vector", "llvm::SmallVector",
                                          "std::list", "std::deque")))));

  // We can't replace push_backs of smart pointer because
  // if emplacement fails (f.e. bad_alloc in vector) we will have leak of
  // passed pointer because smart pointer won't be constructed
  // (and destructed) as in push_back case.
  auto isCtorOfSmartPtr = hasDeclaration(cxxConstructorDecl(
      ofClass(hasAnyName("std::shared_ptr", "std::unique_ptr", "std::auto_ptr",
                         "std::weak_ptr"))));

  // Bitfields binds only to consts and emplace_back take it by universal ref.
  auto bitFieldAsArgument = hasAnyArgument(ignoringParenImpCasts(
      memberExpr(hasDeclaration(fieldDecl(matchers::isBitfield())))));

  // We could have leak of resource.
  auto newExprAsArgument = hasAnyArgument(ignoringParenImpCasts(cxxNewExpr()));
  auto constructingDerived =
      hasParent(implicitCastExpr(hasCastKind(CastKind::CK_DerivedToBase)));

  auto hasInitList = has(ignoringParenImpCasts(initListExpr()));
  auto soughtConstructExpr =
      cxxConstructExpr(
          unless(anyOf(isCtorOfSmartPtr, hasInitList, bitFieldAsArgument,
                       newExprAsArgument, constructingDerived,
                       has(materializeTemporaryExpr(hasInitList)))))
          .bind("ctor");
  auto hasConstructExpr = has(ignoringParenImpCasts(soughtConstructExpr));

  auto ctorAsArgument = materializeTemporaryExpr(
      anyOf(hasConstructExpr, has(cxxFunctionalCastExpr(hasConstructExpr))));

  Finder->addMatcher(
      cxxMemberCallExpr(callPushBack, has(ctorAsArgument)).bind("call"), this);
}
void UniqueptrResetReleaseCheck::registerMatchers(MatchFinder *Finder) {
  // Only register the matchers for C++11; the functionality currently does not
  // provide any benefit to other languages, despite being benign.
  if (!getLangOpts().CPlusPlus11)
    return;

  Finder->addMatcher(
      cxxMemberCallExpr(
          on(expr().bind("left")), callee(memberExpr().bind("reset_member")),
          callee(
              cxxMethodDecl(hasName("reset"),
                            ofClass(cxxRecordDecl(hasName("::std::unique_ptr"),
                                                  decl().bind("left_class"))))),
          has(ignoringParenImpCasts(cxxMemberCallExpr(
              on(expr().bind("right")),
              callee(memberExpr().bind("release_member")),
              callee(cxxMethodDecl(
                  hasName("release"),
                  ofClass(cxxRecordDecl(hasName("::std::unique_ptr"),
                                        decl().bind("right_class")))))))))
          .bind("reset_call"),
      this);
}
void UndelegatedConstructorCheck::registerMatchers(MatchFinder *Finder) {
  // We look for calls to constructors of the same type in constructors. To do
  // this we have to look through a variety of nodes that occur in the path,
  // depending on the type's destructor and the number of arguments on the
  // constructor call, this is handled by ignoringTemporaryExpr. Ignore template
  // instantiations to reduce the number of duplicated warnings.
  //
  // Only register the matchers for C++11; the functionality currently does not
  // provide any benefit to other languages, despite being benign.
  if (!getLangOpts().CPlusPlus11)
    return;

  Finder->addMatcher(
      compoundStmt(
          hasParent(
              cxxConstructorDecl(ofClass(cxxRecordDecl().bind("parent")))),
          forEach(ignoringTemporaryExpr(
              cxxConstructExpr(hasDeclaration(cxxConstructorDecl(ofClass(
                                   cxxRecordDecl(baseOfBoundNode("parent"))))))
                  .bind("construct"))),
          unless(isInTemplateInstantiation())),
      this);
}
TEST_F(StructuralEquivalenceTest, WrongOrderOfFieldsInClass) {
  auto Code = "class X { int a; int b; };";
  auto Decls = makeNamedDecls(Code, Code, Lang_CXX, "X");

  CXXRecordDecl *RD = FirstDeclMatcher<CXXRecordDecl>().match(
      get<1>(Decls), cxxRecordDecl(hasName("X")));
  FieldDecl *FD =
      FirstDeclMatcher<FieldDecl>().match(get<1>(Decls), fieldDecl(hasName("a")));

  // Reorder the FieldDecls
  RD->removeDecl(FD);
  RD->addDeclInternal(FD);

  EXPECT_FALSE(testStructuralMatch(Decls));
}
void TrailingReturnCheck::registerMatchers(MatchFinder *Finder) {

  // Requires C++11 or later.
  if (!getLangOpts().CPlusPlus11)
    return;

  // Functions that have trailing returns are disallowed, except for those
  // using decltype specifiers and lambda with otherwise unutterable
  // return types.
  Finder->addMatcher(
      functionDecl(allOf(hasTrailingReturn(),
                         unless(anyOf(returns(decltypeType()),
                                      hasParent(cxxRecordDecl(isLambda()))))))
          .bind("decl"),
      this);
}
void SizeofContainerCheck::registerMatchers(MatchFinder *Finder) {
  Finder->addMatcher(
      expr(unless(isInTemplateInstantiation()),
           expr(sizeOfExpr(has(ignoringParenImpCasts(
                    expr(hasType(hasCanonicalType(hasDeclaration(cxxRecordDecl(
                        matchesName("^(::std::|::string)"),
                        unless(matchesName("^::std::(bitset|array)$")),
                        hasMethod(cxxMethodDecl(hasName("size"), isPublic(),
                                                isConst())))))))))))
               .bind("sizeof"),
           // Ignore ARRAYSIZE(<array of containers>) pattern.
           unless(hasAncestor(binaryOperator(
               anyOf(hasOperatorName("/"), hasOperatorName("%")),
               hasLHS(ignoringParenCasts(sizeOfExpr(expr()))),
               hasRHS(ignoringParenCasts(equalsBoundNode("sizeof"))))))),
      this);
}
void AvoidConstParamsInDecls::registerMatchers(MatchFinder *Finder) {
  const auto ConstParamDecl =
      parmVarDecl(hasType(qualType(isConstQualified()))).bind("param");
  Finder->addMatcher(
      functionDecl(unless(isDefinition()),
                   // Lambdas are always their own definition, but they
                   // generate a non-definition FunctionDecl too. Ignore those.
                   // Class template instantiations have a non-definition
                   // CXXMethodDecl for methods that aren't used in this
                   // translation unit. Ignore those, as the template will have
                   // already been checked.
                   unless(cxxMethodDecl(ofClass(cxxRecordDecl(anyOf(
                       isLambda(), ast_matchers::isTemplateInstantiation()))))),
                   has(typeLoc(forEach(ConstParamDecl))))
          .bind("func"),
      this);
}
void MoveConstructorInitCheck::registerMatchers(MatchFinder *Finder) {
  // Only register the matchers for C++11; the functionality currently does not
  // provide any benefit to other languages, despite being benign.
  if (!getLangOpts().CPlusPlus11)
    return;

  Finder->addMatcher(
      cxxConstructorDecl(
          unless(isImplicit()),
          allOf(isMoveConstructor(),
                hasAnyConstructorInitializer(
                    cxxCtorInitializer(
                        withInitializer(cxxConstructExpr(hasDeclaration(
                            cxxConstructorDecl(isCopyConstructor())
                                .bind("ctor")))))
                        .bind("move-init")))),
      this);

  auto NonConstValueMovableAndExpensiveToCopy =
      qualType(allOf(unless(pointerType()), unless(isConstQualified()),
                     hasDeclaration(cxxRecordDecl(hasMethod(cxxConstructorDecl(
                         isMoveConstructor(), unless(isDeleted()))))),
                     matchers::isExpensiveToCopy()));

  // This checker is also used to implement cert-oop11-cpp, but when using that
  // form of the checker, we do not want to diagnose movable parameters.
  if (!UseCERTSemantics) {
    Finder->addMatcher(
        cxxConstructorDecl(
            allOf(
                unless(isMoveConstructor()),
                hasAnyConstructorInitializer(withInitializer(cxxConstructExpr(
                    hasDeclaration(cxxConstructorDecl(isCopyConstructor())),
                    hasArgument(
                        0,
                        declRefExpr(
                            to(parmVarDecl(
                                   hasType(
                                       NonConstValueMovableAndExpensiveToCopy))
                                   .bind("movable-param")))
                            .bind("init-arg")))))))
            .bind("ctor-decl"),
        this);
  }
}
void UniqueptrDeleteReleaseCheck::registerMatchers(MatchFinder *Finder) {
  auto IsSusbstituted = qualType(anyOf(
      substTemplateTypeParmType(), hasDescendant(substTemplateTypeParmType())));

  auto UniquePtrWithDefaultDelete = classTemplateSpecializationDecl(
      hasName("std::unique_ptr"),
      hasTemplateArgument(1, refersToType(qualType(hasDeclaration(cxxRecordDecl(
                                 hasName("std::default_delete")))))));

  Finder->addMatcher(
      cxxDeleteExpr(has(ignoringParenImpCasts(cxxMemberCallExpr(
                        on(expr(hasType(UniquePtrWithDefaultDelete),
                                unless(hasType(IsSusbstituted)))
                               .bind("uptr")),
                        callee(cxxMethodDecl(hasName("release")))))))
          .bind("delete"),
      this);
}
void ProperlySeededRandomGeneratorCheck::registerMatchers(MatchFinder *Finder) {
  auto RandomGeneratorEngineDecl = cxxRecordDecl(hasAnyName(
      "::std::linear_congruential_engine", "::std::mersenne_twister_engine",
      "::std::subtract_with_carry_engine", "::std::discard_block_engine",
      "::std::independent_bits_engine", "::std::shuffle_order_engine"));
  auto RandomGeneratorEngineTypeMatcher = hasType(hasUnqualifiedDesugaredType(
      recordType(hasDeclaration(RandomGeneratorEngineDecl))));

  // std::mt19937 engine;
  // engine.seed();
  //        ^
  // engine.seed(1);
  //        ^
  // const int x = 1;
  // engine.seed(x);
  //        ^
  Finder->addMatcher(
      cxxMemberCallExpr(
          has(memberExpr(has(declRefExpr(RandomGeneratorEngineTypeMatcher)),
                         member(hasName("seed")),
                         unless(hasDescendant(cxxThisExpr())))))
          .bind("seed"),
      this);

  // std::mt19937 engine;
  //              ^
  // std::mt19937 engine(1);
  //              ^
  // const int x = 1;
  // std::mt19937 engine(x);
  //              ^
  Finder->addMatcher(
      cxxConstructExpr(RandomGeneratorEngineTypeMatcher).bind("ctor"), this);

  // srand();
  // ^
  // const int x = 1;
  // srand(x);
  // ^
  Finder->addMatcher(
      callExpr(callee(functionDecl(hasAnyName("::srand", "::std::srand"))))
          .bind("srand"),
      this);
}
void StaticObjectExceptionCheck::registerMatchers(MatchFinder *Finder) {
  if ((!getLangOpts().CPlusPlus) || (!getLangOpts().CXXExceptions))
    return;

  // Match any static or thread_local variable declaration that has an
  // initializer that can throw.
  Finder->addMatcher(
      varDecl(anyOf(hasThreadStorageDuration(), hasStaticStorageDuration()),
              unless(anyOf(isConstexpr(), hasType(cxxRecordDecl(isLambda())),
                           hasAncestor(functionDecl()))),
              anyOf(hasDescendant(cxxConstructExpr(hasDeclaration(
                        cxxConstructorDecl(unless(isNoThrow())).bind("func")))),
                    hasDescendant(cxxNewExpr(hasDeclaration(
                        functionDecl(unless(isNoThrow())).bind("func")))),
                    hasDescendant(callExpr(hasDeclaration(
                        functionDecl(unless(isNoThrow())).bind("func"))))))
          .bind("var"),
      this);
}
void ProBoundsConstantArrayIndexCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;

  Finder->addMatcher(arraySubscriptExpr(hasBase(ignoringImpCasts(hasType(
                                            constantArrayType().bind("type")))),
                                        hasIndex(expr().bind("index")))
                         .bind("expr"),
                     this);

  Finder->addMatcher(
      cxxOperatorCallExpr(
          hasOverloadedOperatorName("[]"),
          hasArgument(
              0, hasType(cxxRecordDecl(hasName("::std::array")).bind("type"))),
          hasArgument(1, expr().bind("index")))
          .bind("expr"),
      this);
}
void RedundantMemberInitCheck::registerMatchers(MatchFinder *Finder) {
  auto Construct =
      cxxConstructExpr(
          hasDeclaration(cxxConstructorDecl(hasParent(
              cxxRecordDecl(unless(isTriviallyDefaultConstructible()))))))
          .bind("construct");

  Finder->addMatcher(
      cxxConstructorDecl(
          unless(isDelegatingConstructor()),
          ofClass(unless(
              anyOf(isUnion(), ast_matchers::isTemplateInstantiation()))),
          forEachConstructorInitializer(
              cxxCtorInitializer(isWritten(),
                                 withInitializer(ignoringImplicit(Construct)),
                                 unless(forField(hasType(isConstQualified()))))
                  .bind("init"))),
      this);
}
void SpecialMemberFunctionsCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;
  Finder->addMatcher(
      cxxRecordDecl(
          eachOf(
              has(cxxDestructorDecl(unless(isImplicit())).bind("dtor")),
              has(cxxConstructorDecl(isCopyConstructor(), unless(isImplicit()))
                      .bind("copy-ctor")),
              has(cxxMethodDecl(isCopyAssignmentOperator(),
                                unless(isImplicit()))
                      .bind("copy-assign")),
              has(cxxConstructorDecl(isMoveConstructor(), unless(isImplicit()))
                      .bind("move-ctor")),
              has(cxxMethodDecl(isMoveAssignmentOperator(),
                                unless(isImplicit()))
                      .bind("move-assign"))))
          .bind("class-def"),
      this);
}
void InefficientStringConcatenationCheck::registerMatchers(
    MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;

  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 ContainerSizeEmptyCheck::registerMatchers(MatchFinder *Finder) {
  // Only register the matchers for C++; the functionality currently does not
  // provide any benefit to other languages, despite being benign.
  if (!getLangOpts().CPlusPlus)
    return;

  const auto ValidContainer = cxxRecordDecl(isSameOrDerivedFrom(
      namedDecl(
          has(cxxMethodDecl(
                  isConst(), parameterCountIs(0), isPublic(), hasName("size"),
                  returns(qualType(isInteger(), unless(booleanType()))))
                  .bind("size")),
          has(cxxMethodDecl(isConst(), parameterCountIs(0), isPublic(),
                            hasName("empty"), returns(booleanType()))
                  .bind("empty")))
          .bind("container")));

  const auto WrongUse = anyOf(
      hasParent(binaryOperator(
                    matchers::isComparisonOperator(),
                    hasEitherOperand(ignoringImpCasts(anyOf(
                        integerLiteral(equals(1)), integerLiteral(equals(0))))))
                    .bind("SizeBinaryOp")),
      hasParent(implicitCastExpr(
          hasImplicitDestinationType(booleanType()),
          anyOf(
              hasParent(unaryOperator(hasOperatorName("!")).bind("NegOnSize")),
              anything()))),
      hasParent(explicitCastExpr(hasDestinationType(booleanType()))));

  Finder->addMatcher(
      cxxMemberCallExpr(on(expr(anyOf(hasType(ValidContainer),
                                      hasType(pointsTo(ValidContainer)),
                                      hasType(references(ValidContainer))))
                               .bind("STLObject")),
                        callee(cxxMethodDecl(hasName("size"))), WrongUse)
          .bind("SizeCallExpr"),
      this);
}
void UseEmplaceCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus11)
    return;

  // FIXME: Bunch of functionality that could be easily added:
  // + add handling of `push_front` for std::forward_list, std::list
  // and std::deque.
  // + add handling of `push` for std::stack, std::queue, std::priority_queue
  // + add handling of `insert` for stl associative container, but be careful
  // because this requires special treatment (it could cause performance
  // regression)
  // + match for emplace calls that should be replaced with insertion
  // + match for make_pair calls.
  auto callPushBack = cxxMemberCallExpr(
      hasDeclaration(functionDecl(hasName("push_back"))),
      on(hasType(cxxRecordDecl(hasAnyName(SmallVector<StringRef, 5>(
          ContainersWithPushBack.begin(), ContainersWithPushBack.end()))))));

  // We can't replace push_backs of smart pointer because
  // if emplacement fails (f.e. bad_alloc in vector) we will have leak of
  // passed pointer because smart pointer won't be constructed
  // (and destructed) as in push_back case.
  auto isCtorOfSmartPtr = hasDeclaration(cxxConstructorDecl(ofClass(hasAnyName(
      SmallVector<StringRef, 5>(SmartPointers.begin(), SmartPointers.end())))));

  // Bitfields binds only to consts and emplace_back take it by universal ref.
  auto bitFieldAsArgument = hasAnyArgument(
      ignoringImplicit(memberExpr(hasDeclaration(fieldDecl(isBitField())))));

  // Initializer list can't be passed to universal reference.
  auto initializerListAsArgument = hasAnyArgument(
      ignoringImplicit(cxxConstructExpr(isListInitialization())));

  // We could have leak of resource.
  auto newExprAsArgument = hasAnyArgument(ignoringImplicit(cxxNewExpr()));
  // We would call another constructor.
  auto constructingDerived =
      hasParent(implicitCastExpr(hasCastKind(CastKind::CK_DerivedToBase)));

  // emplace_back can't access private constructor.
  auto isPrivateCtor = hasDeclaration(cxxConstructorDecl(isPrivate()));

  auto hasInitList = has(ignoringImplicit(initListExpr()));
  // FIXME: Discard 0/NULL (as nullptr), static inline const data members,
  // overloaded functions and template names.
  auto soughtConstructExpr =
      cxxConstructExpr(
          unless(anyOf(isCtorOfSmartPtr, hasInitList, bitFieldAsArgument,
                       initializerListAsArgument, newExprAsArgument,
                       constructingDerived, isPrivateCtor)))
          .bind("ctor");
  auto hasConstructExpr = has(ignoringImplicit(soughtConstructExpr));

  auto ctorAsArgument = materializeTemporaryExpr(
      anyOf(hasConstructExpr, has(cxxFunctionalCastExpr(hasConstructExpr))));

  Finder->addMatcher(cxxMemberCallExpr(callPushBack, has(ctorAsArgument),
                                       unless(isInTemplateInstantiation()))
                         .bind("call"),
                     this);
}
Example #27
0
void InheritanceBuilder::tackOnto(MatchFinder &MF) {
  MF.addMatcher(cxxRecordDecl(isDefinition(),
                              unless(hasAncestor(namespaceDecl(isAnonymous()))))
                    .bind("class"),
                this);
}
void CanRunScriptChecker::registerMatchers(MatchFinder *AstMatcher) {
  auto InvalidArg =
      // We want to find any expression,
      ignoreTrivials(expr(
          // which has a refcounted pointer type,
          hasType(pointerType(
              pointee(hasDeclaration(cxxRecordDecl(isRefCounted()))))),
          // and which is not this,
          unless(cxxThisExpr()),
          // and which is not a method call on a smart ptr,
          unless(cxxMemberCallExpr(on(hasType(isSmartPtrToRefCounted())))),
          // and which is not a parameter of the parent function,
          unless(declRefExpr(to(parmVarDecl()))),
          // and which is not a MOZ_KnownLive wrapped value.
          unless(callExpr(callee(functionDecl(hasName("MOZ_KnownLive"))))),
          expr().bind("invalidArg")));

  auto OptionalInvalidExplicitArg = anyOf(
      // We want to find any argument which is invalid.
      hasAnyArgument(InvalidArg),

      // This makes this matcher optional.
      anything());

  // Please not that the hasCanRunScriptAnnotation() matchers are not present
  // directly in the cxxMemberCallExpr, callExpr and constructExpr matchers
  // because we check that the corresponding functions can run script later in
  // the checker code.
  AstMatcher->addMatcher(
      expr(
          anyOf(
              // We want to match a method call expression,
              cxxMemberCallExpr(
                  // which optionally has an invalid arg,
                  OptionalInvalidExplicitArg,
                  // or which optionally has an invalid implicit this argument,
                  anyOf(
                      // which derefs into an invalid arg,
                      on(cxxOperatorCallExpr(
                          anyOf(hasAnyArgument(InvalidArg), anything()))),
                      // or is an invalid arg.
                      on(InvalidArg),

                      anything()),
                  expr().bind("callExpr")),
              // or a regular call expression,
              callExpr(
                  // which optionally has an invalid arg.
                  OptionalInvalidExplicitArg, expr().bind("callExpr")),
              // or a construct expression,
              cxxConstructExpr(
                  // which optionally has an invalid arg.
                  OptionalInvalidExplicitArg, expr().bind("constructExpr"))),

          anyOf(
              // We want to match the parent function.
              forFunction(functionDecl().bind("nonCanRunScriptParentFunction")),

              // ... optionally.
              anything())),
      this);
}
void UpgradeDurationConversionsCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;

  // For the arithmetic calls, we match only the uses of the templated operators
  // where the template parameter is not a built-in type. This means the
  // instantiation makes use of an available user defined conversion to
  // `int64_t`.
  //
  // The implementation of these templates will be updated to fail SFINAE for
  // non-integral types. We match them to suggest an explicit cast.

  // Match expressions like `a *= b` and `a /= b` where `a` has type
  // `absl::Duration` and `b` is not of a built-in type.
  Finder->addMatcher(
      cxxOperatorCallExpr(
          argumentCountIs(2),
          hasArgument(
              0, expr(hasType(cxxRecordDecl(hasName("::absl::Duration"))))),
          hasArgument(1, expr().bind("arg")),
          callee(functionDecl(
              hasParent(functionTemplateDecl()),
              unless(hasTemplateArgument(0, refersToType(builtinType()))),
              hasAnyName("operator*=", "operator/=")))),
      this);

  // Match expressions like `a.operator*=(b)` and `a.operator/=(b)` where `a`
  // has type `absl::Duration` and `b` is not of a built-in type.
  Finder->addMatcher(
      cxxMemberCallExpr(
          callee(cxxMethodDecl(
              ofClass(cxxRecordDecl(hasName("::absl::Duration"))),
              hasParent(functionTemplateDecl()),
              unless(hasTemplateArgument(0, refersToType(builtinType()))),
              hasAnyName("operator*=", "operator/="))),
          argumentCountIs(1), hasArgument(0, expr().bind("arg"))),
      this);

  // Match expressions like `a * b`, `a / b`, `operator*(a, b)`, and
  // `operator/(a, b)` where `a` has type `absl::Duration` and `b` is not of a
  // built-in type.
  Finder->addMatcher(
      callExpr(callee(functionDecl(
                   hasParent(functionTemplateDecl()),
                   unless(hasTemplateArgument(0, refersToType(builtinType()))),
                   hasAnyName("::absl::operator*", "::absl::operator/"))),
               argumentCountIs(2),
               hasArgument(0, expr(hasType(
                                  cxxRecordDecl(hasName("::absl::Duration"))))),
               hasArgument(1, expr().bind("arg"))),
      this);

  // Match expressions like `a * b` and `operator*(a, b)` where `a` is not of a
  // built-in type and `b` has type `absl::Duration`.
  Finder->addMatcher(
      callExpr(callee(functionDecl(
                   hasParent(functionTemplateDecl()),
                   unless(hasTemplateArgument(0, refersToType(builtinType()))),
                   hasName("::absl::operator*"))),
               argumentCountIs(2), hasArgument(0, expr().bind("arg")),
               hasArgument(1, expr(hasType(cxxRecordDecl(
                                  hasName("::absl::Duration")))))),
      this);

  // For the factory functions, we match only the non-templated overloads that
  // take an `int64_t` parameter. Within these calls, we care about implicit
  // casts through a user defined conversion to `int64_t`.
  //
  // The factory functions will be updated to be templated and SFINAE on whether
  // the template parameter is an integral type. This complements the already
  // existing templated overloads that only accept floating point types.

  // Match calls like:
  //   `absl::Nanoseconds(x)`
  //   `absl::Microseconds(x)`
  //   `absl::Milliseconds(x)`
  //   `absl::Seconds(x)`
  //   `absl::Minutes(x)`
  //   `absl::Hours(x)`
  // where `x` is not of a built-in type.
  Finder->addMatcher(
      implicitCastExpr(
          anyOf(hasCastKind(CK_UserDefinedConversion),
                has(implicitCastExpr(hasCastKind(CK_UserDefinedConversion)))),
          hasParent(callExpr(
              callee(functionDecl(DurationFactoryFunction(),
                  unless(hasParent(functionTemplateDecl())))),
              hasArgument(0, expr().bind("arg"))))),
      this);
}
void OverrideBaseCallChecker::registerMatchers(MatchFinder* AstMatcher) {
  AstMatcher->addMatcher(cxxRecordDecl(hasBaseClasses()).bind("class"),
      this);
}