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-rw-r--r--parser/htmlparser/nsScanner.cpp327
1 files changed, 327 insertions, 0 deletions
diff --git a/parser/htmlparser/nsScanner.cpp b/parser/htmlparser/nsScanner.cpp
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+++ b/parser/htmlparser/nsScanner.cpp
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sw=2 et tw=78: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//#define __INCREMENTAL 1
+
+#include "nsScanner.h"
+
+#include "mozilla/Attributes.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Encoding.h"
+#include "nsDebug.h"
+#include "nsReadableUtils.h"
+#include "nsUTF8Utils.h" // for LossyConvertEncoding
+#include "nsCRT.h"
+#include "nsParser.h"
+#include "nsCharsetSource.h"
+
+nsReadEndCondition::nsReadEndCondition(const char16_t* aTerminateChars)
+ : mChars(aTerminateChars),
+ mFilter(char16_t(~0)) // All bits set
+{
+ // Build filter that will be used to filter out characters with
+ // bits that none of the terminal chars have. This works very well
+ // because terminal chars often have only the last 4-6 bits set and
+ // normal ascii letters have bit 7 set. Other letters have even higher
+ // bits set.
+
+ // Calculate filter
+ const char16_t* current = aTerminateChars;
+ char16_t terminalChar = *current;
+ while (terminalChar) {
+ mFilter &= ~terminalChar;
+ ++current;
+ terminalChar = *current;
+ }
+}
+
+/**
+ * Use this constructor if you want i/o to be based on
+ * a single string you hand in during construction.
+ * This short cut was added for Javascript.
+ *
+ * @update gess 5/12/98
+ * @param aMode represents the parser mode (nav, other)
+ * @return
+ */
+nsScanner::nsScanner(const nsAString& anHTMLString, bool aIncremental)
+ : mIncremental(aIncremental) {
+ MOZ_COUNT_CTOR(nsScanner);
+
+ AppendToBuffer(anHTMLString);
+ MOZ_ASSERT(mMarkPosition == mCurrentPosition);
+}
+
+/**
+ * Use this constructor if you want i/o to be based on strings
+ * the scanner receives. If you pass a null filename, you
+ * can still provide data to the scanner via append.
+ */
+nsScanner::nsScanner(nsIURI* aURI) : mURI(aURI), mIncremental(true) {
+ MOZ_COUNT_CTOR(nsScanner);
+
+ // XXX This is a big hack. We need to initialize the iterators to something.
+ // What matters is that mCurrentPosition == mEndPosition, so that our methods
+ // believe that we are at EOF (see bug 182067). We null out mCurrentPosition
+ // so that we have some hope of catching null pointer dereferences associated
+ // with this hack. --darin
+ memset(&mCurrentPosition, 0, sizeof(mCurrentPosition));
+ mMarkPosition = mCurrentPosition;
+ mEndPosition = mCurrentPosition;
+
+ // XML defaults to UTF-8 and about:blank is UTF-8, too.
+ SetDocumentCharset(UTF_8_ENCODING, kCharsetFromDocTypeDefault);
+}
+
+nsresult nsScanner::SetDocumentCharset(NotNull<const Encoding*> aEncoding,
+ int32_t aSource) {
+ if (aSource < mCharsetSource) // priority is lower than the current one
+ return NS_OK;
+
+ mCharsetSource = aSource;
+ nsCString charsetName;
+ aEncoding->Name(charsetName);
+ if (!mCharset.IsEmpty() && charsetName.Equals(mCharset)) {
+ return NS_OK; // no difference, don't change it
+ }
+
+ // different, need to change it
+
+ mCharset.Assign(charsetName);
+
+ mUnicodeDecoder = aEncoding->NewDecoderWithBOMRemoval();
+
+ return NS_OK;
+}
+
+/**
+ * default destructor
+ *
+ * @update gess 3/25/98
+ * @param
+ * @return
+ */
+nsScanner::~nsScanner() { MOZ_COUNT_DTOR(nsScanner); }
+
+/**
+ * Resets current offset position of input stream to marked position.
+ * This allows us to back up to this point if the need should arise,
+ * such as when tokenization gets interrupted.
+ * NOTE: IT IS REALLY BAD FORM TO CALL RELEASE WITHOUT CALLING MARK FIRST!
+ *
+ * @update gess 5/12/98
+ * @param
+ * @return
+ */
+void nsScanner::RewindToMark(void) {
+ if (mSlidingBuffer) {
+ mCurrentPosition = mMarkPosition;
+ }
+}
+
+/**
+ * Records current offset position in input stream. This allows us
+ * to back up to this point if the need should arise, such as when
+ * tokenization gets interrupted.
+ *
+ * @update gess 7/29/98
+ * @param
+ * @return
+ */
+int32_t nsScanner::Mark() {
+ int32_t distance = 0;
+ if (mSlidingBuffer) {
+ nsScannerIterator oldStart;
+ mSlidingBuffer->BeginReading(oldStart);
+
+ distance = Distance(oldStart, mCurrentPosition);
+
+ mSlidingBuffer->DiscardPrefix(mCurrentPosition);
+ mSlidingBuffer->BeginReading(mCurrentPosition);
+ mMarkPosition = mCurrentPosition;
+ }
+
+ return distance;
+}
+
+/**
+ * Insert data to our underlying input buffer as
+ * if it were read from an input stream.
+ *
+ * @update harishd 01/12/99
+ * @return error code
+ */
+bool nsScanner::UngetReadable(const nsAString& aBuffer) {
+ if (!mSlidingBuffer) {
+ return false;
+ }
+
+ mSlidingBuffer->UngetReadable(aBuffer, mCurrentPosition);
+ mSlidingBuffer->BeginReading(
+ mCurrentPosition); // Insertion invalidated our iterators
+ mSlidingBuffer->EndReading(mEndPosition);
+
+ return true;
+}
+
+/**
+ * Append data to our underlying input buffer as
+ * if it were read from an input stream.
+ *
+ * @update gess4/3/98
+ * @return error code
+ */
+nsresult nsScanner::Append(const nsAString& aBuffer) {
+ if (!AppendToBuffer(aBuffer)) return NS_ERROR_OUT_OF_MEMORY;
+ return NS_OK;
+}
+
+/**
+ *
+ *
+ * @update gess 5/21/98
+ * @param
+ * @return
+ */
+nsresult nsScanner::Append(const char* aBuffer, uint32_t aLen) {
+ nsresult res = NS_OK;
+ if (mUnicodeDecoder) {
+ CheckedInt<size_t> needed = mUnicodeDecoder->MaxUTF16BufferLength(aLen);
+ if (!needed.isValid()) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+ CheckedInt<uint32_t> allocLen(1); // null terminator due to legacy sadness
+ allocLen += needed.value();
+ if (!allocLen.isValid()) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+ nsScannerString::Buffer* buffer =
+ nsScannerString::AllocBuffer(allocLen.value());
+ NS_ENSURE_TRUE(buffer, NS_ERROR_OUT_OF_MEMORY);
+ char16_t* unichars = buffer->DataStart();
+
+ uint32_t result;
+ size_t read;
+ size_t written;
+ // Do not use structured binding lest deal with [-Werror=unused-variable]
+ std::tie(result, read, written) =
+ mUnicodeDecoder->DecodeToUTF16WithoutReplacement(
+ AsBytes(Span(aBuffer, aLen)), Span(unichars, needed.value()),
+ false); // Retain bug about failure to handle EOF
+ MOZ_ASSERT(result != kOutputFull);
+ MOZ_ASSERT(read <= aLen);
+ MOZ_ASSERT(written <= needed.value());
+ if (result != kInputEmpty) {
+ // Since about:blank is empty, this line runs only for XML. Use a
+ // character that's illegal in XML instead of U+FFFD in order to make
+ // expat flag the error. There is no need to loop and convert more, since
+ // expat will stop here anyway.
+ unichars[written++] = 0xFFFF;
+ }
+ buffer->SetDataLength(written);
+ // Don't propagate return code of unicode decoder
+ // since it doesn't reflect on our success or failure
+ // - Ref. bug 87110
+ res = NS_OK;
+ AppendToBuffer(buffer);
+ } else {
+ NS_WARNING("No decoder found.");
+ res = NS_ERROR_FAILURE;
+ }
+
+ return res;
+}
+
+/**
+ * retrieve next char from scanners internal input stream
+ *
+ * @update gess 3/25/98
+ * @param
+ * @return error code reflecting read status
+ */
+nsresult nsScanner::GetChar(char16_t& aChar) {
+ if (!mSlidingBuffer || mCurrentPosition == mEndPosition) {
+ aChar = 0;
+ return NS_ERROR_HTMLPARSER_EOF;
+ }
+
+ aChar = *mCurrentPosition++;
+
+ return NS_OK;
+}
+
+void nsScanner::BindSubstring(nsScannerSubstring& aSubstring,
+ const nsScannerIterator& aStart,
+ const nsScannerIterator& aEnd) {
+ aSubstring.Rebind(*mSlidingBuffer, aStart, aEnd);
+}
+
+void nsScanner::CurrentPosition(nsScannerIterator& aPosition) {
+ aPosition = mCurrentPosition;
+}
+
+void nsScanner::EndReading(nsScannerIterator& aPosition) {
+ aPosition = mEndPosition;
+}
+
+void nsScanner::SetPosition(nsScannerIterator& aPosition, bool aTerminate) {
+ if (mSlidingBuffer) {
+ mCurrentPosition = aPosition;
+ if (aTerminate && (mCurrentPosition == mEndPosition)) {
+ mMarkPosition = mCurrentPosition;
+ mSlidingBuffer->DiscardPrefix(mCurrentPosition);
+ }
+ }
+}
+
+void nsScanner::AppendToBuffer(nsScannerString::Buffer* aBuf) {
+ if (!mSlidingBuffer) {
+ mSlidingBuffer = MakeUnique<nsScannerString>(aBuf);
+ mSlidingBuffer->BeginReading(mCurrentPosition);
+ mMarkPosition = mCurrentPosition;
+ } else {
+ mSlidingBuffer->AppendBuffer(aBuf);
+ if (mCurrentPosition == mEndPosition) {
+ mSlidingBuffer->BeginReading(mCurrentPosition);
+ }
+ }
+ mSlidingBuffer->EndReading(mEndPosition);
+}
+
+/**
+ * call this to copy bytes out of the scanner that have not yet been consumed
+ * by the tokenization process.
+ *
+ * @update gess 5/12/98
+ * @param aCopyBuffer is where the scanner buffer will be copied to
+ * @return true if OK or false on OOM
+ */
+bool nsScanner::CopyUnusedData(nsString& aCopyBuffer) {
+ if (!mSlidingBuffer) {
+ aCopyBuffer.Truncate();
+ return true;
+ }
+
+ nsScannerIterator start, end;
+ start = mCurrentPosition;
+ end = mEndPosition;
+
+ return CopyUnicodeTo(start, end, aCopyBuffer);
+}
+
+/**
+ * Conduct self test. Actually, selftesting for this class
+ * occurs in the parser selftest.
+ *
+ * @update gess 3/25/98
+ * @param
+ * @return
+ */
+
+void nsScanner::SelfTest(void) {
+#ifdef _DEBUG
+#endif
+}
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