зеркало из https://github.com/mozilla/gecko-dev.git
586 строки
15 KiB
C++
586 строки
15 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* The contents of this file are subject to the Netscape Public License
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* Version 1.0 (the "NPL"); you may not use this file except in
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* compliance with the NPL. You may obtain a copy of the NPL at
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* http://www.mozilla.org/NPL/
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*
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* Software distributed under the NPL is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
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* for the specific language governing rights and limitations under the
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* NPL.
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*
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* The Initial Developer of this code under the NPL is Netscape
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* Communications Corporation. Portions created by Netscape are
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* Copyright (C) 1998 Netscape Communications Corporation. All Rights
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* Reserved.
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*/
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#include "nsCSSScanner.h"
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#include "nsIInputStream.h"
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#include "nsIUnicharInputStream.h"
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#include "nsString.h"
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#include "nsCRT.h"
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#ifdef NS_DEBUG
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static char* kNullPointer = "null pointer";
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#endif
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// Don't bother collecting whitespace characters in token's mIdent buffer
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#undef COLLECT_WHITESPACE
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#define BUFFER_SIZE 256
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static const PRUnichar CSS_ESCAPE = PRUnichar('\\');
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static const PRUint8 IS_LATIN1 = 0x01;
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static const PRUint8 IS_DIGIT = 0x02;
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static const PRUint8 IS_HEX_DIGIT = 0x04;
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static const PRUint8 IS_ALPHA = 0x08;
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static const PRUint8 START_IDENT = 0x10;
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static const PRUint8 IS_IDENT = 0x20;
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static const PRUint8 IS_WHITESPACE = 0x40;
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static PRUint8* gLexTable;
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static void BuildLexTable()
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{
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PRUint8* lt = new PRUint8[256];
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nsCRT::zero(lt, 256);
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gLexTable = lt;
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int i;
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lt[CSS_ESCAPE] = START_IDENT;
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lt['-'] |= IS_IDENT;
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// XXX add in other whitespace chars
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lt[' '] |= IS_WHITESPACE;
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lt['\t'] |= IS_WHITESPACE;
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lt['\r'] |= IS_WHITESPACE;
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lt['\n'] |= IS_WHITESPACE;
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for (i = 161; i <= 255; i++) {
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lt[i] |= IS_LATIN1 | IS_IDENT | START_IDENT;
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}
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for (i = '0'; i <= '9'; i++) {
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lt[i] |= IS_DIGIT | IS_HEX_DIGIT | IS_IDENT;
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}
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for (i = 'A'; i <= 'Z'; i++) {
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if ((i >= 'A') && (i <= 'F')) {
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lt[i] |= IS_HEX_DIGIT;
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lt[i+32] |= IS_HEX_DIGIT;
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}
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lt[i] |= IS_ALPHA | IS_IDENT | START_IDENT;
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lt[i+32] |= IS_ALPHA | IS_IDENT | START_IDENT;
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}
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}
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nsCSSToken::nsCSSToken()
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{
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mType = eCSSToken_Symbol;
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}
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nsCSSScanner::nsCSSScanner()
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{
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if (nsnull == gLexTable) {
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// XXX need a monitor
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BuildLexTable();
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}
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mInput = nsnull;
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mBuffer = new PRUnichar[BUFFER_SIZE];
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mOffset = 0;
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mCount = 0;
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mLookAhead = -1;
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}
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nsCSSScanner::~nsCSSScanner()
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{
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Close();
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if (nsnull != mBuffer) {
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delete mBuffer;
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mBuffer = nsnull;
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}
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}
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void nsCSSScanner::Init(nsIUnicharInputStream* aInput)
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{
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NS_PRECONDITION(nsnull != aInput, kNullPointer);
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Close();
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mInput = aInput;
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if (nsnull != aInput) {
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aInput->AddRef();
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}
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}
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void nsCSSScanner::Close()
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{
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NS_IF_RELEASE(mInput);
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}
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// Returns -1 on error or eof
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PRInt32 nsCSSScanner::Read(PRInt32* aErrorCode)
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{
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PRInt32 rv;
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if (mLookAhead >= 0) {
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rv = mLookAhead;
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mLookAhead = -1;
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} else {
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if (mCount < 0) {
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return -1;
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}
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if (mOffset == mCount) {
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mOffset = 0;
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mCount = mInput->Read(aErrorCode, mBuffer, 0, BUFFER_SIZE);
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if (mCount <= 0) {
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return -1;
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}
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}
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rv = PRInt32(mBuffer[mOffset++]);
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}
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mLastRead = rv;
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//printf("Read => %x\n", rv);
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return rv;
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}
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PRInt32 nsCSSScanner::Peek(PRInt32* aErrorCode)
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{
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if (mLookAhead < 0) {
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mLookAhead = Read(aErrorCode);
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if (mLookAhead < 0) {
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return -1;
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}
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}
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//printf("Peek => %x\n", mLookAhead);
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return mLookAhead;
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}
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void nsCSSScanner::Unread()
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{
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NS_PRECONDITION((mLastRead >= 0) && (mLookAhead < 0), "double pushback");
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mLookAhead = mLastRead;
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mLastRead = -1;
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}
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PRBool nsCSSScanner::LookAhead(PRInt32* aErrorCode, PRUnichar aChar)
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{
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PRInt32 ch = Read(aErrorCode);
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if (ch < 0) {
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return PR_FALSE;
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}
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if (ch == aChar) {
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return PR_TRUE;
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}
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Unread();
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return PR_FALSE;
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}
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PRBool nsCSSScanner::EatWhiteSpace(PRInt32* aErrorCode)
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{
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PRBool eaten = PR_FALSE;
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for (;;) {
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PRInt32 ch = Read(aErrorCode);
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if (ch < 0) {
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break;
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}
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if ((ch == ' ') || (ch == '\n') || (ch == '\r') || (ch == '\t')) {
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eaten = PR_TRUE;
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continue;
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}
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Unread();
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break;
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}
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return eaten;
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}
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PRBool nsCSSScanner::EatNewline(PRInt32* aErrorCode)
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{
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PRInt32 ch = Read(aErrorCode);
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if (ch < 0) {
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return PR_FALSE;
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}
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PRBool eaten = PR_FALSE;
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if (ch == '\r') {
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eaten = PR_TRUE;
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ch = Peek(aErrorCode);
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if (ch == '\n') {
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(void) Read(aErrorCode);
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}
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} else if (ch == '\n') {
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eaten = PR_TRUE;
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} else {
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Unread();
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}
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return eaten;
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}
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PRBool nsCSSScanner::Next(PRInt32* aErrorCode, nsCSSToken* aToken)
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{
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PRInt32 ch = Read(aErrorCode);
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if (ch < 0) {
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return PR_FALSE;
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}
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if (ch < 256) {
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PRUint8* lexTable = gLexTable;
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// IDENT
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if ((lexTable[ch] & START_IDENT) != 0) {
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return ParseIdent(aErrorCode, ch, aToken);
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}
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// AT_KEYWORD
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if (ch == '@') {
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PRInt32 nextChar = Peek(aErrorCode);
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if ((nextChar >= 0) && (nextChar <= 255)) {
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if ((lexTable[nextChar] & START_IDENT) != 0) {
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return ParseAtKeyword(aErrorCode, ch, aToken);
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}
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}
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}
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// NUMBER or DIM
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if ((ch == '.') || (ch == '+') || (ch == '-')) {
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PRInt32 nextChar = Peek(aErrorCode);
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if ((nextChar >= 0) && (nextChar <= 255)) {
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if ((lexTable[nextChar] & IS_DIGIT) != 0) {
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return ParseNumber(aErrorCode, ch, aToken);
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}
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}
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}
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if ((lexTable[ch] & IS_DIGIT) != 0) {
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return ParseNumber(aErrorCode, ch, aToken);
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}
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// ID
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if (ch == '#') {
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return ParseID(aErrorCode, ch, aToken);
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}
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// STRING
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if ((ch == '"') || (ch == '\'')) {
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return ParseString(aErrorCode, ch, aToken);
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}
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// WS
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if ((lexTable[ch] & IS_WHITESPACE) != 0) {
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aToken->mType = eCSSToken_WhiteSpace;
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aToken->mIdent.SetLength(0);
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aToken->mIdent.Append(PRUnichar(ch));
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(void) EatWhiteSpace(aErrorCode);
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return PR_TRUE;
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}
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if (ch == '/') {
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PRInt32 nextChar = Peek(aErrorCode);
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if (nextChar == '/') {
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(void) Read(aErrorCode);
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aToken->mIdent.SetLength(0);
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aToken->mIdent.Append(PRUnichar(ch));
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aToken->mIdent.Append(PRUnichar(ch));
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return ParseEOLComment(aErrorCode, aToken);
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} else if (nextChar == '*') {
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(void) Read(aErrorCode);
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aToken->mIdent.SetLength(0);
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aToken->mIdent.Append(PRUnichar(ch));
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aToken->mIdent.Append(PRUnichar(nextChar));
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return ParseCComment(aErrorCode, aToken);
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}
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}
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}
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aToken->mType = eCSSToken_Symbol;
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aToken->mSymbol = ch;
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return PR_TRUE;
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}
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PRInt32 nsCSSScanner::ParseEscape(PRInt32* aErrorCode)
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{
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PRUint8* lexTable = gLexTable;
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PRInt32 ch = Peek(aErrorCode);
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if (ch < 0) {
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return CSS_ESCAPE;
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}
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if ((ch <= 255) && ((lexTable[ch] & IS_HEX_DIGIT) != 0)) {
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PRInt32 rv = 0;
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for (int i = 0; i < 4; i++) {
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ch = Read(aErrorCode);
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if (ch < 0) {
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// Whoops: error or premature eof
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break;
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}
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if ((lexTable[ch] & IS_HEX_DIGIT) != 0) {
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if ((lexTable[ch] & IS_DIGIT) != 0) {
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rv = rv * 16 + (ch - '0');
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} else {
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// Note: c&7 just keeps the low three bits which causes
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// upper and lower case alphabetics to both yield their
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// "relative to 10" value for computing the hex value.
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rv = rv * 16 + (ch & 0x7) + 10;
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}
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} else {
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Unread();
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break;
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}
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}
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return rv;
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} else {
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// "Any character except a hexidecimal digit can be escaped to
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// remove its special meaning by putting a backslash in front"
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// -- CSS1 spec section 7.1
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(void) Read(aErrorCode);
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return ch;
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}
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}
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/**
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* Gather up the characters in an identifier. The identfier was
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* started by "aChar" which will be appended to aIdent. The result
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* will be aIdent with all of the identifier characters appended
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* until the first non-identifier character is seen. The termination
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* character is unread for the future re-reading.
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*/
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PRBool nsCSSScanner::GatherIdent(PRInt32* aErrorCode, PRInt32 aChar,
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nsString& aIdent)
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{
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if (aChar == CSS_ESCAPE) {
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aChar = ParseEscape(aErrorCode);
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}
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for (;;) {
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aChar = Read(aErrorCode);
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if (aChar < 0) break;
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if (aChar == CSS_ESCAPE) {
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aChar = ParseEscape(aErrorCode);
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aIdent.Append(PRUnichar(aChar));
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} else if ((aChar <= 255) && ((gLexTable[aChar] & IS_IDENT) != 0)) {
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aIdent.Append(PRUnichar(aChar));
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} else {
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Unread();
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break;
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}
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}
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return PR_TRUE;
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}
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PRBool nsCSSScanner::ParseID(PRInt32* aErrorCode,
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PRInt32 aChar,
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nsCSSToken* aToken)
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{
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aToken->mIdent.SetLength(0);
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aToken->mType = eCSSToken_ID;
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return GatherIdent(aErrorCode, aChar, aToken->mIdent);
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}
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PRBool nsCSSScanner::ParseIdent(PRInt32* aErrorCode,
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PRInt32 aChar,
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nsCSSToken* aToken)
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{
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nsString& ident = aToken->mIdent;
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ident.SetLength(0);
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ident.Append(PRUnichar(aChar));
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if (!GatherIdent(aErrorCode, aChar, ident)) {
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return PR_FALSE;
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}
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// Process a url lexical token. A CSS1 url token can contain
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// characters beyond identifier characters (e.g. '/', ':', etc.)
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// Because of this the normal rules for tokenizing the input don't
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// apply very well. To simplify the parser and relax some of the
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// requirements on the scanner we parse url's here. If we find a
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// malformed URL then we emit a token of type "InvalidURL" so that
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// the CSS1 parser can ignore the invalid input. We attempt to eat
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// the right amount of input data when an invalid URL is presented.
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nsCSSTokenType tokenType = eCSSToken_Ident;
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if (ident.EqualsIgnoreCase("url")) {
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tokenType = eCSSToken_InvalidURL;
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if (LookAhead(aErrorCode, '(')) {
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// Skip leading whitespace
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(void) EatWhiteSpace(aErrorCode);
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ident.SetLength(0);
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PRInt32 c = Read(aErrorCode);
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if (c == ')') {
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// empty url spec: this is invalid
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} else if ((c == '"') || (c == '\'')) {
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// start of a quoted url
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if (!GatherString(aErrorCode, c, ident)) {
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return PR_FALSE;
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}
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if (!EatWhiteSpace(aErrorCode)) {
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return PR_FALSE;
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}
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if (LookAhead(aErrorCode, ')')) {
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tokenType = eCSSToken_URL;
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}
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} else {
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// start of a non-quoted url
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Unread();
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PRBool ok = PR_TRUE;
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for (;;) {
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c = Read(aErrorCode);
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if (c < 0) break;
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if (c == CSS_ESCAPE) {
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c = ParseEscape(aErrorCode);
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ident.Append(PRUnichar(c));
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} else if ((c == '"') || (c == '\'') || (c == '(')) {
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// This is an invalid URL spec
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ok = PR_FALSE;
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} else if ((256 >= c) && ((gLexTable[c] & IS_WHITESPACE) != 0)) {
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// Whitespace is allowed at the end of the URL
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(void) EatWhiteSpace(aErrorCode);
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if (LookAhead(aErrorCode, ')')) {
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// done!
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break;
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}
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// Whitespace is followed by something other than a
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// ")". This is an invalid url spec.
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ok = PR_FALSE;
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} else if (c == ')') {
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// All done
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break;
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} else {
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// A regular url character.
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ident.Append(PRUnichar(c));
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}
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}
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// If the result of the above scanning is ok then change the token
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// type to a useful one.
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if (ok) {
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tokenType = eCSSToken_URL;
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}
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}
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}
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}
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aToken->mType = tokenType;
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return PR_TRUE;
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}
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PRBool nsCSSScanner::ParseAtKeyword(PRInt32* aErrorCode, PRInt32 aChar,
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nsCSSToken* aToken)
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{
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aToken->mIdent.SetLength(0);
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aToken->mType = eCSSToken_AtKeyword;
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return GatherIdent(aErrorCode, aChar, aToken->mIdent);
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}
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PRBool nsCSSScanner::ParseNumber(PRInt32* aErrorCode, PRInt32 c,
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nsCSSToken* aToken)
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{
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nsString& ident = aToken->mIdent;
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ident.SetLength(0);
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PRBool gotDot = (c == '.') ? PR_TRUE : PR_FALSE;
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if (c != '+') {
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ident.Append(PRUnichar(c));
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}
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// Gather up characters that make up the number
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PRUint8* lexTable = gLexTable;
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for (;;) {
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c = Read(aErrorCode);
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if (c < 0) break;
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if (!gotDot && (c == '.')) {
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gotDot = PR_TRUE;
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} else if ((c > 255) || ((lexTable[c] & IS_DIGIT) == 0)) {
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break;
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}
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ident.Append(PRUnichar(c));
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}
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// Convert number to floating point
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nsCSSTokenType type = eCSSToken_Number;
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PRInt32 ec;
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float value = ident.ToFloat(&ec);
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// Look at character that terminated the number
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aToken->mIntegerValid = PR_FALSE;
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if (c >= 0) {
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if ((c <= 255) && ((lexTable[c] & START_IDENT) != 0)) {
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ident.SetLength(0);
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ident.Append(PRUnichar(c));
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if (!GatherIdent(aErrorCode, c, ident)) {
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return PR_FALSE;
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}
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type = eCSSToken_Dimension;
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} else if ('%' == c) {
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type = eCSSToken_Percentage;
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value = value / 100.0f;
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} else {
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// Put back character that stopped numeric scan
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Unread();
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if (!gotDot) {
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aToken->mInteger = ident.ToInteger(&ec);
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aToken->mIntegerValid = PR_TRUE;
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}
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ident.SetLength(0);
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}
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}
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aToken->mNumber = value;
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aToken->mType = type;
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return PR_TRUE;
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}
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PRBool nsCSSScanner::ParseCComment(PRInt32* aErrorCode, nsCSSToken* aToken)
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{
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nsString& ident = aToken->mIdent;
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for (;;) {
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PRInt32 ch = Read(aErrorCode);
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if (ch < 0) break;
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if (ch == '*') {
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if (LookAhead(aErrorCode, '/')) {
|
|
ident.Append(PRUnichar(ch));
|
|
ident.Append('/');
|
|
break;
|
|
}
|
|
}
|
|
#ifdef COLLECT_WHITESPACE
|
|
ident.Append(PRUnichar(ch));
|
|
#endif
|
|
}
|
|
aToken->mType = eCSSToken_WhiteSpace;
|
|
return PR_TRUE;
|
|
}
|
|
|
|
PRBool nsCSSScanner::ParseEOLComment(PRInt32* aErrorCode, nsCSSToken* aToken)
|
|
{
|
|
nsString& ident = aToken->mIdent;
|
|
ident.SetLength(0);
|
|
for (;;) {
|
|
if (EatNewline(aErrorCode)) {
|
|
break;
|
|
}
|
|
PRInt32 ch = Read(aErrorCode);
|
|
if (ch < 0) {
|
|
break;
|
|
}
|
|
#ifdef COLLECT_WHITESPACE
|
|
ident.Append(PRUnichar(ch));
|
|
#endif
|
|
}
|
|
aToken->mType = eCSSToken_WhiteSpace;
|
|
return PR_TRUE;
|
|
}
|
|
|
|
PRBool nsCSSScanner::GatherString(PRInt32* aErrorCode, PRInt32 aStop,
|
|
nsString& aBuffer)
|
|
{
|
|
for (;;) {
|
|
PRInt32 ch = Read(aErrorCode);
|
|
if (ch < 0) {
|
|
return PR_FALSE;
|
|
}
|
|
if (ch == aStop) {
|
|
break;
|
|
}
|
|
if (ch == CSS_ESCAPE) {
|
|
ch = ParseEscape(aErrorCode);
|
|
if (ch < 0) {
|
|
return PR_FALSE;
|
|
}
|
|
}
|
|
aBuffer.Append(PRUnichar(ch));
|
|
}
|
|
return PR_TRUE;
|
|
}
|
|
|
|
PRBool nsCSSScanner::ParseString(PRInt32* aErrorCode, PRInt32 aStop,
|
|
nsCSSToken* aToken)
|
|
{
|
|
aToken->mIdent.SetLength(0);
|
|
aToken->mType = eCSSToken_String;
|
|
return GatherString(aErrorCode, aStop, aToken->mIdent);
|
|
}
|