From 5aa8225f493dc3c3171662fecc8a9ff5d0a16feb Mon Sep 17 00:00:00 2001 From: m-holger Date: Sat, 25 Jun 2022 15:59:39 +0100 Subject: Refactor QPDFObjectTypeAccessor and QPDFObjectHandle::dereference --- libqpdf/QPDFObjectHandle.cc | 161 ++++++++++++++------------------------------ 1 file changed, 51 insertions(+), 110 deletions(-) (limited to 'libqpdf/QPDFObjectHandle.cc') diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc index b3f21a27..4ef4f4d9 100644 --- a/libqpdf/QPDFObjectHandle.cc +++ b/libqpdf/QPDFObjectHandle.cc @@ -284,23 +284,14 @@ QPDFObjectHandle::isInitialized() const QPDFObject::object_type_e QPDFObjectHandle::getTypeCode() { - if (this->initialized) { - dereference(); - return this->obj->getTypeCode(); - } else { - return QPDFObject::ot_uninitialized; - } + return dereference() ? + this->obj->getTypeCode() : QPDFObject::ot_uninitialized; } char const* QPDFObjectHandle::getTypeName() { - if (this->initialized) { - dereference(); - return this->obj->getTypeName(); - } else { - return "uninitialized"; - } + return dereference() ? this->obj->getTypeName() : "uninitialized"; } namespace @@ -310,14 +301,9 @@ namespace { public: static bool - check(QPDFObject* o) + check(std::shared_ptr const& o) { - return (o && dynamic_cast(o)); - } - static bool - check(QPDFObject const* o) - { - return (o && dynamic_cast(o)); + return (o && dynamic_cast(o.get())); } }; } // namespace @@ -325,11 +311,7 @@ namespace bool QPDFObjectHandle::isBool() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool @@ -339,37 +321,25 @@ QPDFObjectHandle::isDirectNull() const // objid == 0, so there's nothing to resolve. return ( this->initialized && (getObjectID() == 0) && - QPDFObjectTypeAccessor::check(obj.get())); + QPDFObjectTypeAccessor::check(obj)); } bool QPDFObjectHandle::isNull() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isInteger() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isReal() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool @@ -406,91 +376,58 @@ QPDFObjectHandle::getValueAsNumber(double& value) bool QPDFObjectHandle::isName() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isString() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isOperator() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isInlineImage() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && + QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isArray() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isDictionary() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && + QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isStream() { - if (!this->initialized) { - return false; - } - dereference(); - return QPDFObjectTypeAccessor::check(obj.get()); + return dereference() && QPDFObjectTypeAccessor::check(obj); } bool QPDFObjectHandle::isReserved() { - if (!this->initialized) { - return false; - } // dereference will clear reserved if this has been replaced - dereference(); - return this->reserved; + return dereference() && this->reserved; } bool QPDFObjectHandle::isIndirect() { - if (!this->initialized) { - return false; - } - return (getObjectID() != 0); + return this->initialized && (getObjectID() != 0); } bool @@ -1748,8 +1685,10 @@ QPDFObjectHandle::unparse() std::string QPDFObjectHandle::unparseResolved() { - dereference(); - if (this->reserved) { + if (!dereference()) { + throw std::logic_error( + "attempted to dereference an uninitialized QPDFObjectHandle"); + } else if (this->reserved) { throw std::logic_error( "QPDFObjectHandle: attempting to unparse a reserved object"); } @@ -1778,12 +1717,13 @@ QPDFObjectHandle::getJSON(int json_version, bool dereference_indirect) { if ((!dereference_indirect) && this->isIndirect()) { return JSON::makeString(unparse()); + } else if (!dereference()) { + throw std::logic_error( + "attempted to dereference an uninitialized QPDFObjectHandle"); + } else if (this->reserved) { + throw std::logic_error( + "QPDFObjectHandle: attempting to unparse a reserved object"); } else { - dereference(); - if (this->reserved) { - throw std::logic_error( - "QPDFObjectHandle: attempting to unparse a reserved object"); - } return this->obj->getJSON(json_version); } } @@ -2524,8 +2464,11 @@ QPDFObjectHandle::parseInternal( qpdf_offset_t QPDFObjectHandle::getParsedOffset() { - dereference(); - return this->obj->getParsedOffset(); + if (dereference()) { + return this->obj->getParsedOffset(); + } else { + return -1; + } } void @@ -2723,6 +2666,7 @@ QPDFObjectHandle::newStream(QPDF* qpdf) QPDFObjectHandle stream_dict = newDictionary(); QPDFObjectHandle result = qpdf->makeIndirectObject( QPDFObjectHandle(new QPDF_Stream(qpdf, 0, 0, stream_dict, 0, 0))); + // Indirect objects are guaranteed to be initialized result.dereference(); QPDF_Stream* stream = dynamic_cast(result.obj.get()); stream->setObjGen(result.getObjectID(), result.getGeneration()); @@ -2771,21 +2715,15 @@ QPDFObjectHandle::setObjectDescription( { // This is called during parsing on newly created direct objects, // so we can't call dereference() here. - if (isInitialized() && this->obj.get()) { - this->obj->setDescription(owning_qpdf, object_description); + if (isInitialized() && obj.get()) { + obj->setDescription(owning_qpdf, object_description); } } bool QPDFObjectHandle::hasObjectDescription() { - if (isInitialized()) { - dereference(); - if (this->obj.get()) { - return this->obj->hasDescription(); - } - } - return false; + return dereference() && obj.get() && obj->hasDescription(); } QPDFObjectHandle @@ -2868,7 +2806,6 @@ QPDFObjectHandle::copyObject( " reserved object handle direct"); } - dereference(); this->qpdf = 0; this->objid = 0; this->generation = 0; @@ -2971,7 +2908,12 @@ QPDFObjectHandle::typeWarning( { QPDF* context = nullptr; std::string description; - dereference(); + // Type checks above guarantee that the object has been dereferenced. + // Nevertheless, dereference throws exceptions in the test suite + if (!dereference()) { + throw std::logic_error( + "attempted to dereference an uninitialized QPDFObjectHandle"); + } this->obj->getDescription(context, description); // Null context handled by warn warn( @@ -2991,8 +2933,7 @@ QPDFObjectHandle::warnIfPossible(std::string const& warning) { QPDF* context = 0; std::string description; - dereference(); - if (this->obj->getDescription(context, description)) { + if (dereference() && obj->getDescription(context, description)) { warn(context, QPDFExc(qpdf_e_damaged_pdf, "", description, 0, warning)); } else { *QPDFLogger::defaultLogger()->getError() << warning << "\n"; @@ -3004,7 +2945,7 @@ QPDFObjectHandle::objectWarning(std::string const& warning) { QPDF* context = nullptr; std::string description; - dereference(); + // Type checks above guarantee that the object has been dereferenced. this->obj->getDescription(context, description); // Null context handled by warn warn(context, QPDFExc(qpdf_e_object, "", description, 0, warning)); @@ -3187,12 +3128,11 @@ QPDFObjectHandle::assertPageObject() } } -void +bool QPDFObjectHandle::dereference() { if (!this->initialized) { - throw std::logic_error( - "attempted to dereference an uninitialized QPDFObjectHandle"); + return false; } if (this->obj.get() && getObjectID() && QPDF::Resolver::objectChanged(this->qpdf, getObjGen(), this->obj)) { @@ -3213,6 +3153,7 @@ QPDFObjectHandle::dereference() this->obj = obj; } } + return true; } void -- cgit v1.2.3-54-g00ecf