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SR-2301 - Fix XMLParser #700

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Merged
merged 4 commits into from
Nov 29, 2016
Merged

SR-2301 - Fix XMLParser #700

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167b47f
Make API conform to the documented contract. Add a few tests.
Oct 28, 2016
b3955c2
Fix a number of bugs with the libxml2 parser usage.
Oct 28, 2016
567fd93
Merge branch 'master' into bugfix/SR-2301
Oct 28, 2016
377daa9
Fix the prefix when namespace processing is disabled.
Oct 28, 2016
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4 changes: 2 additions & 2 deletions CoreFoundation/Base.subproj/ForSwiftFoundationOnly.h
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Original file line number Diff line number Diff line change
Expand Up @@ -171,7 +171,7 @@ struct _NSXMLParserBridge {
void (*startElementNs)(_CFXMLInterface ctx,
const unsigned char *localname,
const unsigned char *_Nullable prefix,
const unsigned char *URI,
const unsigned char *_Nullable URI,
int nb_namespaces,
const unsigned char *_Nullable *_Nonnull namespaces,
int nb_attributes,
Expand All @@ -180,7 +180,7 @@ struct _NSXMLParserBridge {
void (*endElementNs)(_CFXMLInterface ctx,
const unsigned char *localname,
const unsigned char *_Nullable prefix,
const unsigned char *URI);
const unsigned char *_Nullable URI);
void (*characters)(_CFXMLInterface ctx,
const unsigned char *ch,
int len);
Expand Down
187 changes: 87 additions & 100 deletions Foundation/NSXMLParser.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,8 @@ extension XMLParser {
}
}

private func UTF8STRING(_ bytes: UnsafePointer<UInt8>) -> String? {
private func UTF8STRING(_ bytes: UnsafePointer<UInt8>?) -> String? {
guard let bytes = bytes else { return nil }
// strlen operates on the wrong type, char*. We can't rebind the memory to a different type without knowing it's length,
// but since we know strlen is in libc, its safe to directly bitcast the pointer without worrying about multiple accesses
// of different types visible to the compiler.
Expand Down Expand Up @@ -243,16 +244,10 @@ internal func _colonSeparatedStringFromPrefixAndSuffix(_ prefix: UnsafePointer<U
return "\(prefixString!):\(suffixString!)"
}

internal func _NSXMLParserStartElementNs(_ ctx: _CFXMLInterface, localname: UnsafePointer<UInt8>, prefix: UnsafePointer<UInt8>?, URI: UnsafePointer<UInt8>, nb_namespaces: Int32, namespaces: UnsafeMutablePointer<UnsafePointer<UInt8>?>, nb_attributes: Int32, nb_defaulted: Int32, attributes: UnsafeMutablePointer<UnsafePointer<UInt8>?>) -> Void {
internal func _NSXMLParserStartElementNs(_ ctx: _CFXMLInterface, localname: UnsafePointer<UInt8>, prefix: UnsafePointer<UInt8>?, URI: UnsafePointer<UInt8>?, nb_namespaces: Int32, namespaces: UnsafeMutablePointer<UnsafePointer<UInt8>?>, nb_attributes: Int32, nb_defaulted: Int32, attributes: UnsafeMutablePointer<UnsafePointer<UInt8>?>) -> Void {
let parser = ctx.parser
let reportQNameURI = parser.shouldProcessNamespaces
let reportNamespaces = parser.shouldReportNamespacePrefixes
// Since strlen is in libc, it's safe to bitcast the UInt8 pointer argument to an Int8 (char *) pointer.
let prefixLen = prefix != nil ? UInt(strlen(unsafeBitCast(prefix!, to: UnsafePointer<Int8>.self))) : 0
let localnameString = (prefixLen == 0 || reportQNameURI) ? UTF8STRING(localname) : nil
let qualifiedNameString = prefixLen != 0 ? _colonSeparatedStringFromPrefixAndSuffix(prefix!, UInt(prefixLen), localname, UInt(strlen(unsafeBitCast(localname, to: UnsafePointer<Int8>.self)))) : localnameString
let namespaceURIString = reportQNameURI ? UTF8STRING(URI) : nil


var nsDict = [String:String]()
var attrDict = [String:String]()
if nb_attributes + nb_namespaces > 0 {
Expand All @@ -274,7 +269,7 @@ internal func _NSXMLParserStartElementNs(_ ctx: _CFXMLInterface, localname: Unsa
nsDict[k] = v
}
}
if !reportQNameURI {
if !parser.shouldProcessNamespaces {
if let k = asAttrNamespaceNameString,
let v = namespaceValueString {
attrDict[k] = v
Expand Down Expand Up @@ -323,37 +318,47 @@ internal func _NSXMLParserStartElementNs(_ ctx: _CFXMLInterface, localname: Unsa
}

}

if let delegate = parser.delegate {
if reportQNameURI {
delegate.parser(parser, didStartElement: localnameString!, namespaceURI: (namespaceURIString != nil ? namespaceURIString : ""), qualifiedName: (qualifiedNameString != nil ? qualifiedNameString : ""), attributes: attrDict)
} else {
delegate.parser(parser, didStartElement: qualifiedNameString!, namespaceURI: nil, qualifiedName: nil, attributes: attrDict)

var elementName: String = UTF8STRING(localname)!
var namespaceURI: String? = nil
var qualifiedName: String? = nil
if parser.shouldProcessNamespaces {
namespaceURI = UTF8STRING(URI) ?? ""
qualifiedName = elementName
if let prefix = UTF8STRING(prefix) {
qualifiedName = elementName + ":" + prefix
}
}
else if let prefix = UTF8STRING(prefix) {
elementName = elementName + ":" + prefix
}

parser.delegate?.parser(parser, didStartElement: elementName, namespaceURI: namespaceURI, qualifiedName: qualifiedName, attributes: attrDict)
}

internal func _NSXMLParserEndElementNs(_ ctx: _CFXMLInterface , localname: UnsafePointer<UInt8>, prefix: UnsafePointer<UInt8>?, URI: UnsafePointer<UInt8>) -> Void {
internal func _NSXMLParserEndElementNs(_ ctx: _CFXMLInterface , localname: UnsafePointer<UInt8>, prefix: UnsafePointer<UInt8>?, URI: UnsafePointer<UInt8>?) -> Void {
let parser = ctx.parser
let reportQNameURI = parser.shouldProcessNamespaces
let prefixLen = prefix != nil ? strlen(unsafeBitCast(prefix!, to: UnsafePointer<Int8>.self)) : 0
let localnameString = (prefixLen == 0 || reportQNameURI) ? UTF8STRING(localname) : nil
let nilStr: String? = nil
let qualifiedNameString = (prefixLen != 0) ? _colonSeparatedStringFromPrefixAndSuffix(prefix!, UInt(prefixLen), localname, UInt(strlen(unsafeBitCast(localname, to: UnsafePointer<Int8>.self)))) : nilStr
let namespaceURIString = reportQNameURI ? UTF8STRING(URI) : nilStr


if let delegate = parser.delegate {
if reportQNameURI {
// When reporting namespace info, the delegate parameters are not passed in nil
delegate.parser(parser, didEndElement: localnameString!, namespaceURI: namespaceURIString == nil ? "" : namespaceURIString, qualifiedName: qualifiedNameString == nil ? "" : qualifiedNameString)
} else {
delegate.parser(parser, didEndElement: qualifiedNameString!, namespaceURI: nil, qualifiedName: nil)

var elementName: String = UTF8STRING(localname)!
var namespaceURI: String? = nil
var qualifiedName: String? = nil
if parser.shouldProcessNamespaces {
namespaceURI = UTF8STRING(URI) ?? ""
qualifiedName = elementName
if let prefix = UTF8STRING(prefix) {
qualifiedName = elementName + ":" + prefix
}
}

else if let prefix = UTF8STRING(prefix) {
elementName = elementName + ":" + prefix
}

parser.delegate?.parser(parser, didEndElement: elementName, namespaceURI: namespaceURI, qualifiedName: qualifiedName)

// Pop the last namespaces that were pushed (safe since XML is balanced)
parser._popNamespaces()
if parser.shouldReportNamespacePrefixes {
parser._popNamespaces()
}
}

internal func _NSXMLParserCharacters(_ ctx: _CFXMLInterface, ch: UnsafePointer<UInt8>, len: Int32) -> Void {
Expand Down Expand Up @@ -410,8 +415,10 @@ open class XMLParser : NSObject {
private var _handler: _CFXMLInterfaceSAXHandler
internal var _stream: InputStream?
internal var _data: Data?

internal var _chunkSize = Int(4096 * 32) // a suitably large number for a decent chunk size
internal var _haveDetectedEncoding = false
// This chunk of data stores the head of the stream. We know we have enough information for encoding
// when there are atleast 4 bytes in here.
internal var _bomChunk: Data?
fileprivate var _parserContext: _CFXMLInterfaceParserContext?
internal var _delegateAborted = false
Expand Down Expand Up @@ -500,72 +507,52 @@ open class XMLParser : NSObject {

internal func parseData(_ data: Data) -> Bool {
_CFXMLInterfaceSetStructuredErrorFunc(interface, _structuredErrorFunc)
var result = true
/* The vast majority of this method just deals with ensuring we do a single parse
on the first 4 received bytes before continuing on to the actual incremental section */
if _haveDetectedEncoding {
var totalLength = data.count
if let chunk = _bomChunk {
totalLength += chunk.count
}
if (totalLength < 4) {
if let chunk = _bomChunk {
var newData = Data()
newData.append(chunk)
newData.append(data)
_bomChunk = newData
} else {
_bomChunk = data
}
} else {
var allExistingData: Data
if let chunk = _bomChunk {
var newData = Data()
newData.append(chunk)
newData.append(data)
allExistingData = newData
} else {
allExistingData = data
}

var handler: _CFXMLInterfaceSAXHandler? = nil
if delegate != nil {
handler = _handler
}

_parserContext = allExistingData.withUnsafeBytes { (bytes: UnsafePointer<Int8>) -> _CFXMLInterfaceParserContext in
return _CFXMLInterfaceCreatePushParserCtxt(handler, interface, bytes, 4, nil)
}

var options = _kCFXMLInterfaceRecover | _kCFXMLInterfaceNoEnt // substitute entities, recover on errors
if shouldResolveExternalEntities {
options |= _kCFXMLInterfaceDTDLoad
}

if handler == nil {
options |= (_kCFXMLInterfaceNoError | _kCFXMLInterfaceNoWarning)
}

_CFXMLInterfaceCtxtUseOptions(_parserContext, options)
_haveDetectedEncoding = true
_bomChunk = nil

if (totalLength > 4) {
let remainingData = allExistingData.withUnsafeMutableBytes { (bytes: UnsafeMutablePointer<UInt8>) -> Data in
let ptr = bytes.advanced(by: 4)
return Data(bytesNoCopy: ptr, count: totalLength - 4, deallocator: .none)
}

let _ = parseData(remainingData)
let handler: _CFXMLInterfaceSAXHandler? = (delegate != nil ? _handler : nil)
let unparsedData: Data
// If the parser context is nil, we have not received enough bytes to create the push parser
if _parserContext == nil {
// Look at the bomChunk and this data
let bomChunk: Data = {
guard var bomChunk = _bomChunk else {
return data
}
bomChunk.append(data)
return bomChunk
}()
// If we have not received 4 bytes, save the bomChunk for next pass
if bomChunk.count < 4 {
_bomChunk = bomChunk
return false
}
} else {
let parseResult = data.withUnsafeBytes { (bytes: UnsafePointer<Int8>) -> Int32 in
return _CFXMLInterfaceParseChunk(_parserContext, bytes, Int32(data.count), 0)
// Prepare options (substitute entities, recover on errors)
var options = _kCFXMLInterfaceRecover | _kCFXMLInterfaceNoEnt
if shouldResolveExternalEntities {
options |= _kCFXMLInterfaceDTDLoad
}
if handler == nil {
options |= (_kCFXMLInterfaceNoError | _kCFXMLInterfaceNoWarning)
}

// Create the push context with the first 4 bytes
bomChunk.withUnsafeBytes { bytes in
_parserContext = _CFXMLInterfaceCreatePushParserCtxt(handler, interface, bytes, 4, nil)
}

result = _handleParseResult(parseResult)
_CFXMLInterfaceCtxtUseOptions(_parserContext, options)
// Prepare the remaining data for parsing
let dataRange = bomChunk.indices
let unparsed = Range(uncheckedBounds: (dataRange.startIndex.advanced(by: 4), dataRange.endIndex))
unparsedData = bomChunk.subdata(in: unparsed)
}
else {
unparsedData = data
}

let parseResult = unparsedData.withUnsafeBytes { (bytes: UnsafePointer<Int8>) -> Int32 in
return _CFXMLInterfaceParseChunk(_parserContext, bytes, Int32(unparsedData.count), 0)
}

let result = _handleParseResult(parseResult)
_CFXMLInterfaceSetStructuredErrorFunc(interface, nil)
return result
}
Expand Down Expand Up @@ -745,13 +732,13 @@ public protocol XMLParserDelegate: class {
func parser(_ parser: XMLParser, resolveExternalEntityName name: String, systemID: String?) -> Data?
// this gives the delegate an opportunity to resolve an external entity itself and reply with the resulting data.

func parser(_ parser: XMLParser, parseErrorOccurred parseError: NSError)
func parser(_ parser: XMLParser, parseErrorOccurred parseError: Error)
// ...and this reports a fatal error to the delegate. The parser will stop parsing.

func parser(_ parser: XMLParser, validationErrorOccurred validationError: NSError)
func parser(_ parser: XMLParser, validationErrorOccurred validationError: Error)
}

extension XMLParserDelegate {
public extension XMLParserDelegate {

func parserDidStartDocument(_ parser: XMLParser) { }
func parserDidEndDocument(_ parser: XMLParser) { }
Expand Down Expand Up @@ -788,9 +775,9 @@ extension XMLParserDelegate {

func parser(_ parser: XMLParser, resolveExternalEntityName name: String, systemID: String?) -> Data? { return nil }

func parser(_ parser: XMLParser, parseErrorOccurred parseError: NSError) { }
func parser(_ parser: XMLParser, parseErrorOccurred parseError: Error) { }

func parser(_ parser: XMLParser, validationErrorOccurred validationError: NSError) { }
func parser(_ parser: XMLParser, validationErrorOccurred validationError: Error) { }
}

extension XMLParser {
Expand Down
2 changes: 1 addition & 1 deletion TestFoundation/TestNSXMLDocument.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@
import Foundation
import XCTest
#else
@testable import SwiftFoundation
import SwiftFoundation
import SwiftXCTest
#endif

Expand Down
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