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gecko-dev/layout/style/nsCSSScanner.cpp
Gervase Markham 82ff7027aa Bug 716478 - update licence to MPL 2.
2012-05-21 12:12:37 +01:00

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/* tokenization of CSS style sheets */
#include <math.h> // must be first due to symbol conflicts
#include "nsCSSScanner.h"
#include "nsString.h"
#include "nsCRT.h"
#include "mozilla/Util.h"
// for #ifdef CSS_REPORT_PARSE_ERRORS
#include "nsCOMPtr.h"
#include "nsIServiceManager.h"
#include "nsIComponentManager.h"
#include "nsReadableUtils.h"
#include "nsIURI.h"
#include "nsIConsoleService.h"
#include "nsIScriptError.h"
#include "nsIStringBundle.h"
#include "nsIDocument.h"
#include "mozilla/Services.h"
#include "mozilla/css/Loader.h"
#include "nsCSSStyleSheet.h"
#include "mozilla/Preferences.h"
using namespace mozilla;
#ifdef CSS_REPORT_PARSE_ERRORS
static bool gReportErrors = true;
static nsIConsoleService *gConsoleService;
static nsIFactory *gScriptErrorFactory;
static nsIStringBundle *gStringBundle;
#endif
static const PRUint8 IS_HEX_DIGIT = 0x01;
static const PRUint8 START_IDENT = 0x02;
static const PRUint8 IS_IDENT = 0x04;
static const PRUint8 IS_WHITESPACE = 0x08;
static const PRUint8 IS_URL_CHAR = 0x10;
#define W IS_WHITESPACE
#define I IS_IDENT
#define U IS_URL_CHAR
#define S START_IDENT
#define UI IS_IDENT |IS_URL_CHAR
#define USI IS_IDENT|START_IDENT |IS_URL_CHAR
#define UXI IS_IDENT |IS_HEX_DIGIT|IS_URL_CHAR
#define UXSI IS_IDENT|START_IDENT|IS_HEX_DIGIT|IS_URL_CHAR
static const PRUint8 gLexTable[] = {
// TAB LF FF CR
0, 0, 0, 0, 0, 0, 0, 0, 0, W, W, 0, W, W, 0, 0,
//
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
// SPC ! " # $ % & ' ( ) * + , - . /
W, U, 0, U, U, U, U, 0, 0, 0, U, U, U, UI, U, U,
// 0 1 2 3 4 5 6 7 8 9 : ; < = > ?
UXI,UXI,UXI,UXI,UXI,UXI,UXI,UXI,UXI,UXI,U, U, U, U, U, U,
// @ A B C D E F G H I J K L M N O
U,UXSI,UXSI,UXSI,UXSI,UXSI,UXSI,USI,USI,USI,USI,USI,USI,USI,USI,USI,
// P Q R S T U V W X Y Z [ \ ] ^ _
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,U, S, U, U, USI,
// ` a b c d e f g h i j k l m n o
U,UXSI,UXSI,UXSI,UXSI,UXSI,UXSI,USI,USI,USI,USI,USI,USI,USI,USI,USI,
// p q r s t u v w x y z { | } ~
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,U, U, U, U, 0,
// U+008*
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
// U+009*
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
// U+00A*
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,
// U+00B*
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,
// U+00C*
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,
// U+00D*
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,
// U+00E*
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,
// U+00F*
USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI,USI
};
MOZ_STATIC_ASSERT(NS_ARRAY_LENGTH(gLexTable) == 256,
"gLexTable expected to cover all 2^8 possible PRUint8s");
#undef W
#undef S
#undef I
#undef U
#undef UI
#undef USI
#undef UXI
#undef UXSI
static inline bool
IsIdentStart(PRInt32 aChar)
{
return aChar >= 0 &&
(aChar >= 256 || (gLexTable[aChar] & START_IDENT) != 0);
}
static inline bool
StartsIdent(PRInt32 aFirstChar, PRInt32 aSecondChar)
{
return IsIdentStart(aFirstChar) ||
(aFirstChar == '-' && IsIdentStart(aSecondChar));
}
static inline bool
IsWhitespace(PRInt32 ch) {
return PRUint32(ch) < 256 && (gLexTable[ch] & IS_WHITESPACE) != 0;
}
static inline bool
IsDigit(PRInt32 ch) {
return (ch >= '0') && (ch <= '9');
}
static inline bool
IsHexDigit(PRInt32 ch) {
return PRUint32(ch) < 256 && (gLexTable[ch] & IS_HEX_DIGIT) != 0;
}
static inline bool
IsIdent(PRInt32 ch) {
return ch >= 0 && (ch >= 256 || (gLexTable[ch] & IS_IDENT) != 0);
}
static inline bool
IsURLChar(PRInt32 ch) {
return ch >= 0 && (ch >= 256 || (gLexTable[ch] & IS_URL_CHAR) != 0);
}
static inline PRUint32
DecimalDigitValue(PRInt32 ch)
{
return ch - '0';
}
static inline PRUint32
HexDigitValue(PRInt32 ch)
{
if (IsDigit(ch)) {
return DecimalDigitValue(ch);
} else {
// Note: c&7 just keeps the low three bits which causes
// upper and lower case alphabetics to both yield their
// "relative to 10" value for computing the hex value.
return (ch & 0x7) + 9;
}
}
nsCSSToken::nsCSSToken()
{
mType = eCSSToken_Symbol;
}
void
nsCSSToken::AppendToString(nsString& aBuffer)
{
switch (mType) {
case eCSSToken_AtKeyword:
aBuffer.Append(PRUnichar('@')); // fall through intentional
case eCSSToken_Ident:
case eCSSToken_WhiteSpace:
case eCSSToken_Function:
case eCSSToken_HTMLComment:
case eCSSToken_URange:
aBuffer.Append(mIdent);
if (mType == eCSSToken_Function)
aBuffer.Append(PRUnichar('('));
break;
case eCSSToken_URL:
case eCSSToken_Bad_URL:
aBuffer.AppendLiteral("url(");
if (mSymbol != PRUnichar(0)) {
aBuffer.Append(mSymbol);
}
aBuffer.Append(mIdent);
if (mSymbol != PRUnichar(0)) {
aBuffer.Append(mSymbol);
}
if (mType == eCSSToken_URL) {
aBuffer.Append(PRUnichar(')'));
}
break;
case eCSSToken_Number:
if (mIntegerValid) {
aBuffer.AppendInt(mInteger, 10);
}
else {
aBuffer.AppendFloat(mNumber);
}
break;
case eCSSToken_Percentage:
NS_ASSERTION(!mIntegerValid, "How did a percentage token get this set?");
aBuffer.AppendFloat(mNumber * 100.0f);
aBuffer.Append(PRUnichar('%'));
break;
case eCSSToken_Dimension:
if (mIntegerValid) {
aBuffer.AppendInt(mInteger, 10);
}
else {
aBuffer.AppendFloat(mNumber);
}
aBuffer.Append(mIdent);
break;
case eCSSToken_String:
aBuffer.Append(mSymbol);
aBuffer.Append(mIdent); // fall through intentional
case eCSSToken_Symbol:
aBuffer.Append(mSymbol);
break;
case eCSSToken_ID:
case eCSSToken_Ref:
aBuffer.Append(PRUnichar('#'));
aBuffer.Append(mIdent);
break;
case eCSSToken_Includes:
aBuffer.AppendLiteral("~=");
break;
case eCSSToken_Dashmatch:
aBuffer.AppendLiteral("|=");
break;
case eCSSToken_Beginsmatch:
aBuffer.AppendLiteral("^=");
break;
case eCSSToken_Endsmatch:
aBuffer.AppendLiteral("$=");
break;
case eCSSToken_Containsmatch:
aBuffer.AppendLiteral("*=");
break;
case eCSSToken_Bad_String:
aBuffer.Append(mSymbol);
aBuffer.Append(mIdent);
break;
default:
NS_ERROR("invalid token type");
break;
}
}
nsCSSScanner::nsCSSScanner()
: mReadPointer(nsnull)
, mSVGMode(false)
#ifdef CSS_REPORT_PARSE_ERRORS
, mError(mErrorBuf, ArrayLength(mErrorBuf), 0)
, mInnerWindowID(0)
, mWindowIDCached(false)
, mSheet(nsnull)
, mLoader(nsnull)
#endif
{
MOZ_COUNT_CTOR(nsCSSScanner);
mPushback = mLocalPushback;
mPushbackSize = ArrayLength(mLocalPushback);
// No need to init the other members, since they represent state
// which can get cleared. We'll init them every time Init() is
// called.
}
nsCSSScanner::~nsCSSScanner()
{
MOZ_COUNT_DTOR(nsCSSScanner);
Close();
if (mLocalPushback != mPushback) {
delete [] mPushback;
}
}
#ifdef CSS_REPORT_PARSE_ERRORS
#define CSS_ERRORS_PREF "layout.css.report_errors"
static int
CSSErrorsPrefChanged(const char *aPref, void *aClosure)
{
gReportErrors = Preferences::GetBool(CSS_ERRORS_PREF, true);
return NS_OK;
}
#endif
/* static */ bool
nsCSSScanner::InitGlobals()
{
#ifdef CSS_REPORT_PARSE_ERRORS
if (gConsoleService && gScriptErrorFactory)
return true;
nsresult rv = CallGetService(NS_CONSOLESERVICE_CONTRACTID, &gConsoleService);
NS_ENSURE_SUCCESS(rv, false);
rv = CallGetClassObject(NS_SCRIPTERROR_CONTRACTID, &gScriptErrorFactory);
NS_ENSURE_SUCCESS(rv, false);
NS_ASSERTION(gConsoleService && gScriptErrorFactory,
"unexpected null pointer without failure");
Preferences::RegisterCallback(CSSErrorsPrefChanged, CSS_ERRORS_PREF);
CSSErrorsPrefChanged(CSS_ERRORS_PREF, nsnull);
#endif
return true;
}
/* static */ void
nsCSSScanner::ReleaseGlobals()
{
#ifdef CSS_REPORT_PARSE_ERRORS
Preferences::UnregisterCallback(CSSErrorsPrefChanged, CSS_ERRORS_PREF);
NS_IF_RELEASE(gConsoleService);
NS_IF_RELEASE(gScriptErrorFactory);
NS_IF_RELEASE(gStringBundle);
#endif
}
void
nsCSSScanner::Init(const nsAString& aBuffer,
nsIURI* aURI, PRUint32 aLineNumber,
nsCSSStyleSheet* aSheet, mozilla::css::Loader* aLoader)
{
NS_PRECONDITION(!mReadPointer, "Should not have an existing input buffer!");
mReadPointer = aBuffer.BeginReading();
mCount = aBuffer.Length();
#ifdef CSS_REPORT_PARSE_ERRORS
// If aURI is the same as mURI, no need to reget mFileName -- it
// shouldn't have changed.
if (aURI != mURI) {
mURI = aURI;
if (aURI) {
aURI->GetSpec(mFileName);
} else {
mFileName.Adopt(NS_strdup("from DOM"));
}
}
#endif // CSS_REPORT_PARSE_ERRORS
mLineNumber = aLineNumber;
// Reset variables that we use to keep track of our progress through the input
mOffset = 0;
mPushbackCount = 0;
#ifdef CSS_REPORT_PARSE_ERRORS
mColNumber = 0;
mSheet = aSheet;
mLoader = aLoader;
#endif
}
#ifdef CSS_REPORT_PARSE_ERRORS
// @see REPORT_UNEXPECTED_EOF in nsCSSParser.cpp
#define REPORT_UNEXPECTED_EOF(lf_) \
ReportUnexpectedEOF(#lf_)
void
nsCSSScanner::AddToError(const nsSubstring& aErrorText)
{
if (mError.IsEmpty()) {
mErrorLineNumber = mLineNumber;
mErrorColNumber = mColNumber;
mError = aErrorText;
} else {
mError.Append(NS_LITERAL_STRING(" ") + aErrorText);
}
}
void
nsCSSScanner::ClearError()
{
mError.Truncate();
}
void
nsCSSScanner::OutputError()
{
if (mError.IsEmpty()) return;
// Log it to the Error console
if (InitGlobals() && gReportErrors) {
if (!mWindowIDCached) {
if (mSheet) {
mInnerWindowID = mSheet->FindOwningWindowInnerID();
}
if (mInnerWindowID == 0 && mLoader) {
nsIDocument* doc = mLoader->GetDocument();
if (doc) {
mInnerWindowID = doc->InnerWindowID();
}
}
mWindowIDCached = true;
}
nsresult rv;
nsCOMPtr<nsIScriptError> errorObject =
do_CreateInstance(gScriptErrorFactory, &rv);
if (NS_SUCCEEDED(rv)) {
rv = errorObject->InitWithWindowID(mError.get(),
NS_ConvertUTF8toUTF16(mFileName).get(),
EmptyString().get(),
mErrorLineNumber,
mErrorColNumber,
nsIScriptError::warningFlag,
"CSS Parser",
mInnerWindowID);
if (NS_SUCCEEDED(rv)) {
gConsoleService->LogMessage(errorObject);
}
}
}
ClearError();
}
static bool
InitStringBundle()
{
if (gStringBundle)
return true;
nsCOMPtr<nsIStringBundleService> sbs =
mozilla::services::GetStringBundleService();
if (!sbs)
return false;
nsresult rv =
sbs->CreateBundle("chrome://global/locale/css.properties", &gStringBundle);
if (NS_FAILED(rv)) {
gStringBundle = nsnull;
return false;
}
return true;
}
#define ENSURE_STRINGBUNDLE \
PR_BEGIN_MACRO if (!InitStringBundle()) return; PR_END_MACRO
// aMessage must take no parameters
void nsCSSScanner::ReportUnexpected(const char* aMessage)
{
ENSURE_STRINGBUNDLE;
nsXPIDLString str;
gStringBundle->GetStringFromName(NS_ConvertASCIItoUTF16(aMessage).get(),
getter_Copies(str));
AddToError(str);
}
void
nsCSSScanner::ReportUnexpectedParams(const char* aMessage,
const PRUnichar **aParams,
PRUint32 aParamsLength)
{
NS_PRECONDITION(aParamsLength > 0, "use the non-params version");
ENSURE_STRINGBUNDLE;
nsXPIDLString str;
gStringBundle->FormatStringFromName(NS_ConvertASCIItoUTF16(aMessage).get(),
aParams, aParamsLength,
getter_Copies(str));
AddToError(str);
}
// aLookingFor is a plain string, not a format string
void
nsCSSScanner::ReportUnexpectedEOF(const char* aLookingFor)
{
ENSURE_STRINGBUNDLE;
nsXPIDLString innerStr;
gStringBundle->GetStringFromName(NS_ConvertASCIItoUTF16(aLookingFor).get(),
getter_Copies(innerStr));
const PRUnichar *params[] = {
innerStr.get()
};
nsXPIDLString str;
gStringBundle->FormatStringFromName(NS_LITERAL_STRING("PEUnexpEOF2").get(),
params, ArrayLength(params),
getter_Copies(str));
AddToError(str);
}
// aLookingFor is a single character
void
nsCSSScanner::ReportUnexpectedEOF(PRUnichar aLookingFor)
{
ENSURE_STRINGBUNDLE;
const PRUnichar lookingForStr[] = {
PRUnichar('\''), aLookingFor, PRUnichar('\''), PRUnichar(0)
};
const PRUnichar *params[] = { lookingForStr };
nsXPIDLString str;
gStringBundle->FormatStringFromName(NS_LITERAL_STRING("PEUnexpEOF2").get(),
params, ArrayLength(params),
getter_Copies(str));
AddToError(str);
}
// aMessage must take 1 parameter (for the string representation of the
// unexpected token)
void
nsCSSScanner::ReportUnexpectedToken(nsCSSToken& tok,
const char *aMessage)
{
ENSURE_STRINGBUNDLE;
nsAutoString tokenString;
tok.AppendToString(tokenString);
const PRUnichar *params[] = {
tokenString.get()
};
ReportUnexpectedParams(aMessage, params);
}
// aParams's first entry must be null, and we'll fill in the token
void
nsCSSScanner::ReportUnexpectedTokenParams(nsCSSToken& tok,
const char* aMessage,
const PRUnichar **aParams,
PRUint32 aParamsLength)
{
NS_PRECONDITION(aParamsLength > 1, "use the non-params version");
NS_PRECONDITION(aParams[0] == nsnull, "first param should be empty");
ENSURE_STRINGBUNDLE;
nsAutoString tokenString;
tok.AppendToString(tokenString);
aParams[0] = tokenString.get();
ReportUnexpectedParams(aMessage, aParams, aParamsLength);
}
#else
#define REPORT_UNEXPECTED_EOF(lf_)
#endif // CSS_REPORT_PARSE_ERRORS
void
nsCSSScanner::Close()
{
mReadPointer = nsnull;
// Clean things up so we don't hold on to memory if our parser gets recycled.
#ifdef CSS_REPORT_PARSE_ERRORS
mFileName.Truncate();
mURI = nsnull;
mError.Truncate();
mInnerWindowID = 0;
mWindowIDCached = false;
mSheet = nsnull;
mLoader = nsnull;
#endif
if (mPushback != mLocalPushback) {
delete [] mPushback;
mPushback = mLocalPushback;
mPushbackSize = ArrayLength(mLocalPushback);
}
}
// Returns -1 on error or eof
PRInt32
nsCSSScanner::Read()
{
PRInt32 rv;
if (0 < mPushbackCount) {
rv = PRInt32(mPushback[--mPushbackCount]);
} else {
if (mOffset == mCount) {
return -1;
}
rv = PRInt32(mReadPointer[mOffset++]);
// There are four types of newlines in CSS: "\r", "\n", "\r\n", and "\f".
// To simplify dealing with newlines, they are all normalized to "\n" here
if (rv == '\r') {
if (mOffset < mCount && mReadPointer[mOffset] == '\n') {
mOffset++;
}
rv = '\n';
} else if (rv == '\f') {
rv = '\n';
}
if (rv == '\n') {
// 0 is a magical line number meaning that we don't know (i.e., script)
if (mLineNumber != 0)
++mLineNumber;
#ifdef CSS_REPORT_PARSE_ERRORS
mColNumber = 0;
} else {
mColNumber++;
#endif
}
}
return rv;
}
PRInt32
nsCSSScanner::Peek()
{
if (0 == mPushbackCount) {
PRInt32 ch = Read();
if (ch < 0) {
return -1;
}
mPushback[0] = PRUnichar(ch);
mPushbackCount++;
}
return PRInt32(mPushback[mPushbackCount - 1]);
}
void
nsCSSScanner::Pushback(PRUnichar aChar)
{
if (mPushbackCount == mPushbackSize) { // grow buffer
PRUnichar* newPushback = new PRUnichar[mPushbackSize + 4];
if (nsnull == newPushback) {
return;
}
mPushbackSize += 4;
memcpy(newPushback, mPushback, sizeof(PRUnichar) * mPushbackCount);
if (mPushback != mLocalPushback) {
delete [] mPushback;
}
mPushback = newPushback;
}
mPushback[mPushbackCount++] = aChar;
}
bool
nsCSSScanner::LookAhead(PRUnichar aChar)
{
PRInt32 ch = Read();
if (ch < 0) {
return false;
}
if (ch == aChar) {
return true;
}
Pushback(ch);
return false;
}
bool
nsCSSScanner::LookAheadOrEOF(PRUnichar aChar)
{
PRInt32 ch = Read();
if (ch < 0) {
return true;
}
if (ch == aChar) {
return true;
}
Pushback(ch);
return false;
}
void
nsCSSScanner::EatWhiteSpace()
{
for (;;) {
PRInt32 ch = Read();
if (ch < 0) {
break;
}
if ((ch != ' ') && (ch != '\n') && (ch != '\t')) {
Pushback(ch);
break;
}
}
}
bool
nsCSSScanner::Next(nsCSSToken& aToken)
{
for (;;) { // Infinite loop so we can restart after comments.
PRInt32 ch = Read();
if (ch < 0) {
return false;
}
// UNICODE-RANGE
if ((ch == 'u' || ch == 'U') && Peek() == '+')
return ParseURange(ch, aToken);
// IDENT
if (StartsIdent(ch, Peek()))
return ParseIdent(ch, aToken);
// AT_KEYWORD
if (ch == '@') {
PRInt32 nextChar = Read();
if (nextChar >= 0) {
PRInt32 followingChar = Peek();
Pushback(nextChar);
if (StartsIdent(nextChar, followingChar))
return ParseAtKeyword(ch, aToken);
}
}
// NUMBER or DIM
if ((ch == '.') || (ch == '+') || (ch == '-')) {
PRInt32 nextChar = Peek();
if (IsDigit(nextChar)) {
return ParseNumber(ch, aToken);
}
else if (('.' == nextChar) && ('.' != ch)) {
nextChar = Read();
PRInt32 followingChar = Peek();
Pushback(nextChar);
if (IsDigit(followingChar))
return ParseNumber(ch, aToken);
}
}
if (IsDigit(ch)) {
return ParseNumber(ch, aToken);
}
// ID
if (ch == '#') {
return ParseRef(ch, aToken);
}
// STRING
if ((ch == '"') || (ch == '\'')) {
return ParseString(ch, aToken);
}
// WS
if (IsWhitespace(ch)) {
aToken.mType = eCSSToken_WhiteSpace;
aToken.mIdent.Assign(PRUnichar(ch));
EatWhiteSpace();
return true;
}
if (ch == '/' && !IsSVGMode()) {
PRInt32 nextChar = Peek();
if (nextChar == '*') {
Read();
// FIXME: Editor wants comments to be preserved (bug 60290).
if (!SkipCComment()) {
return false;
}
continue; // start again at the beginning
}
}
if (ch == '<') { // consume HTML comment tags
if (LookAhead('!')) {
if (LookAhead('-')) {
if (LookAhead('-')) {
aToken.mType = eCSSToken_HTMLComment;
aToken.mIdent.AssignLiteral("<!--");
return true;
}
Pushback('-');
}
Pushback('!');
}
}
if (ch == '-') { // check for HTML comment end
if (LookAhead('-')) {
if (LookAhead('>')) {
aToken.mType = eCSSToken_HTMLComment;
aToken.mIdent.AssignLiteral("-->");
return true;
}
Pushback('-');
}
}
// INCLUDES ("~=") and DASHMATCH ("|=")
if (( ch == '|' ) || ( ch == '~' ) || ( ch == '^' ) ||
( ch == '$' ) || ( ch == '*' )) {
PRInt32 nextChar = Read();
if ( nextChar == '=' ) {
if (ch == '~') {
aToken.mType = eCSSToken_Includes;
}
else if (ch == '|') {
aToken.mType = eCSSToken_Dashmatch;
}
else if (ch == '^') {
aToken.mType = eCSSToken_Beginsmatch;
}
else if (ch == '$') {
aToken.mType = eCSSToken_Endsmatch;
}
else if (ch == '*') {
aToken.mType = eCSSToken_Containsmatch;
}
return true;
} else if (nextChar >= 0) {
Pushback(nextChar);
}
}
aToken.mType = eCSSToken_Symbol;
aToken.mSymbol = ch;
return true;
}
}
bool
nsCSSScanner::NextURL(nsCSSToken& aToken)
{
EatWhiteSpace();
PRInt32 ch = Read();
if (ch < 0) {
return false;
}
// STRING
if ((ch == '"') || (ch == '\'')) {
#ifdef DEBUG
bool ok =
#endif
ParseString(ch, aToken);
NS_ABORT_IF_FALSE(ok, "ParseString should never fail, "
"since there's always something read");
NS_ABORT_IF_FALSE(aToken.mType == eCSSToken_String ||
aToken.mType == eCSSToken_Bad_String,
"unexpected token type");
if (NS_LIKELY(aToken.mType == eCSSToken_String)) {
EatWhiteSpace();
if (LookAheadOrEOF(')')) {
aToken.mType = eCSSToken_URL;
} else {
aToken.mType = eCSSToken_Bad_URL;
}
} else {
aToken.mType = eCSSToken_Bad_URL;
}
return true;
}
// Process a url lexical token. A CSS1 url token can contain
// characters beyond identifier characters (e.g. '/', ':', etc.)
// Because of this the normal rules for tokenizing the input don't
// apply very well. To simplify the parser and relax some of the
// requirements on the scanner we parse url's here. If we find a
// malformed URL then we emit a token of type "Bad_URL" so that
// the CSS1 parser can ignore the invalid input. The parser must
// treat a Bad_URL token like a Function token, and process
// tokens until a matching parenthesis.
aToken.mType = eCSSToken_Bad_URL;
aToken.mSymbol = PRUnichar(0);
nsString& ident = aToken.mIdent;
ident.SetLength(0);
// start of a non-quoted url (which may be empty)
bool ok = true;
for (;;) {
if (IsURLChar(ch)) {
// A regular url character.
ident.Append(PRUnichar(ch));
} else if (ch == ')') {
// All done
break;
} else if (IsWhitespace(ch)) {
// Whitespace is allowed at the end of the URL
EatWhiteSpace();
// Consume the close paren if we have it; if not we're an invalid URL.
ok = LookAheadOrEOF(')');
break;
} else if (ch == '\\') {
if (!ParseAndAppendEscape(ident, false)) {
ok = false;
Pushback(ch);
break;
}
} else {
// This is an invalid URL spec
ok = false;
Pushback(ch); // push it back so the parser can match tokens and
// then closing parenthesis
break;
}
ch = Read();
if (ch < 0) {
break;
}
}
// If the result of the above scanning is ok then change the token
// type to a useful one.
if (ok) {
aToken.mType = eCSSToken_URL;
}
return true;
}
/**
* Returns whether an escape was succesfully parsed; if it was not,
* the backslash needs to be its own symbol token.
*/
bool
nsCSSScanner::ParseAndAppendEscape(nsString& aOutput, bool aInString)
{
PRInt32 ch = Read();
if (ch < 0) {
return false;
}
if (IsHexDigit(ch)) {
PRInt32 rv = 0;
int i;
Pushback(ch);
for (i = 0; i < 6; i++) { // up to six digits
ch = Read();
if (ch < 0) {
// Whoops: error or premature eof
break;
}
if (!IsHexDigit(ch) && !IsWhitespace(ch)) {
Pushback(ch);
break;
} else if (IsHexDigit(ch)) {
rv = rv * 16 + HexDigitValue(ch);
} else {
NS_ASSERTION(IsWhitespace(ch), "bad control flow");
// single space ends escape
break;
}
}
if (6 == i) { // look for trailing whitespace and eat it
ch = Peek();
if (IsWhitespace(ch)) {
(void) Read();
}
}
NS_ASSERTION(rv >= 0, "How did rv become negative?");
// "[at most six hexadecimal digits following a backslash] stand
// for the ISO 10646 character with that number, which must not be
// zero. (It is undefined in CSS 2.1 what happens if a style sheet
// does contain a character with Unicode codepoint zero.)"
// -- CSS2.1 section 4.1.3
//
// Silently deleting \0 opens a content-filtration loophole (see
// bug 228856), so what we do instead is pretend the "cancels the
// meaning of special characters" rule applied.
if (rv > 0) {
AppendUCS4ToUTF16(ENSURE_VALID_CHAR(rv), aOutput);
} else {
while (i--)
aOutput.Append('0');
if (IsWhitespace(ch))
Pushback(ch);
}
return true;
}
// "Any character except a hexidecimal digit can be escaped to
// remove its special meaning by putting a backslash in front"
// -- CSS1 spec section 7.1
if (ch == '\n') {
if (!aInString) {
// Outside of strings (which includes url() that contains a
// string), escaped newlines aren't special, and just tokenize as
// eCSSToken_Symbol (DELIM).
Pushback(ch);
return false;
}
// In strings (and in url() containing a string), escaped newlines
// are just dropped to allow splitting over multiple lines.
} else {
aOutput.Append(ch);
}
return true;
}
/**
* Gather up the characters in an identifier. The identfier was
* started by "aChar" which will be appended to aIdent. The result
* will be aIdent with all of the identifier characters appended
* until the first non-identifier character is seen. The termination
* character is unread for the future re-reading.
*
* Returns failure when the character sequence does not form an ident at
* all, in which case the caller is responsible for pushing back or
* otherwise handling aChar. (This occurs only when aChar is '\'.)
*/
bool
nsCSSScanner::GatherIdent(PRInt32 aChar, nsString& aIdent)
{
if (aChar == '\\') {
if (!ParseAndAppendEscape(aIdent, false)) {
return false;
}
}
else if (0 < aChar) {
aIdent.Append(aChar);
}
for (;;) {
// If nothing in pushback, first try to get as much as possible in one go
if (!mPushbackCount && mOffset < mCount) {
// See how much we can consume and append in one go
PRUint32 n = mOffset;
// Count number of Ident characters that can be processed
while (n < mCount && IsIdent(mReadPointer[n])) {
++n;
}
// Add to the token what we have so far
if (n > mOffset) {
#ifdef CSS_REPORT_PARSE_ERRORS
mColNumber += n - mOffset;
#endif
aIdent.Append(&mReadPointer[mOffset], n - mOffset);
mOffset = n;
}
}
aChar = Read();
if (aChar < 0) break;
if (aChar == '\\') {
if (!ParseAndAppendEscape(aIdent, false)) {
Pushback(aChar);
break;
}
} else if (IsIdent(aChar)) {
aIdent.Append(PRUnichar(aChar));
} else {
Pushback(aChar);
break;
}
}
return true;
}
bool
nsCSSScanner::ParseRef(PRInt32 aChar, nsCSSToken& aToken)
{
// Fall back for when we don't have name characters following:
aToken.mType = eCSSToken_Symbol;
aToken.mSymbol = aChar;
PRInt32 ch = Read();
if (ch < 0) {
return true;
}
if (IsIdent(ch) || ch == '\\') {
// First char after the '#' is a valid ident char (or an escape),
// so it makes sense to keep going
nsCSSTokenType type =
StartsIdent(ch, Peek()) ? eCSSToken_ID : eCSSToken_Ref;
aToken.mIdent.SetLength(0);
if (GatherIdent(ch, aToken.mIdent)) {
aToken.mType = type;
return true;
}
}
// No ident chars after the '#'. Just unread |ch| and get out of here.
Pushback(ch);
return true;
}
bool
nsCSSScanner::ParseIdent(PRInt32 aChar, nsCSSToken& aToken)
{
nsString& ident = aToken.mIdent;
ident.SetLength(0);
if (!GatherIdent(aChar, ident)) {
aToken.mType = eCSSToken_Symbol;
aToken.mSymbol = aChar;
return true;
}
nsCSSTokenType tokenType = eCSSToken_Ident;
// look for functions (ie: "ident(")
if (Peek() == PRUnichar('(')) {
Read();
tokenType = eCSSToken_Function;
if (ident.LowerCaseEqualsLiteral("url")) {
NextURL(aToken); // ignore return value, since *we* read something
return true;
}
}
aToken.mType = tokenType;
return true;
}
bool
nsCSSScanner::ParseAtKeyword(PRInt32 aChar, nsCSSToken& aToken)
{
aToken.mIdent.SetLength(0);
aToken.mType = eCSSToken_AtKeyword;
if (!GatherIdent(0, aToken.mIdent)) {
aToken.mType = eCSSToken_Symbol;
aToken.mSymbol = PRUnichar('@');
}
return true;
}
bool
nsCSSScanner::ParseNumber(PRInt32 c, nsCSSToken& aToken)
{
NS_PRECONDITION(c == '.' || c == '+' || c == '-' || IsDigit(c),
"Why did we get called?");
aToken.mHasSign = (c == '+' || c == '-');
// Our sign.
PRInt32 sign = c == '-' ? -1 : 1;
// Absolute value of the integer part of the mantissa. This is a double so
// we don't run into overflow issues for consumers that only care about our
// floating-point value while still being able to express the full PRInt32
// range for consumers who want integers.
double intPart = 0;
// Fractional part of the mantissa. This is a double so that when we convert
// to float at the end we'll end up rounding to nearest float instead of
// truncating down (as we would if fracPart were a float and we just
// effectively lost the last several digits).
double fracPart = 0;
// Absolute value of the power of 10 that we should multiply by (only
// relevant for numbers in scientific notation). Has to be a signed integer,
// because multiplication of signed by unsigned converts the unsigned to
// signed, so if we plan to actually multiply by expSign...
PRInt32 exponent = 0;
// Sign of the exponent.
PRInt32 expSign = 1;
if (aToken.mHasSign) {
NS_ASSERTION(c != '.', "How did that happen?");
c = Read();
}
bool gotDot = (c == '.');
if (!gotDot) {
// Parse the integer part of the mantisssa
NS_ASSERTION(IsDigit(c), "Why did we get called?");
do {
intPart = 10*intPart + DecimalDigitValue(c);
c = Read();
// The IsDigit check will do the right thing even if Read() returns < 0
} while (IsDigit(c));
gotDot = (c == '.') && IsDigit(Peek());
}
if (gotDot) {
// Parse the fractional part of the mantissa.
c = Read();
NS_ASSERTION(IsDigit(c), "How did we get here?");
// Power of ten by which we need to divide our next digit
float divisor = 10;
do {
fracPart += DecimalDigitValue(c) / divisor;
divisor *= 10;
c = Read();
// The IsDigit check will do the right thing even if Read() returns < 0
} while (IsDigit(c));
}
bool gotE = false;
if (IsSVGMode() && (c == 'e' || c == 'E')) {
PRInt32 nextChar = Peek();
PRInt32 expSignChar = 0;
if (nextChar == '-' || nextChar == '+') {
expSignChar = Read();
nextChar = Peek();
}
if (IsDigit(nextChar)) {
gotE = true;
if (expSignChar == '-') {
expSign = -1;
}
c = Read();
NS_ASSERTION(IsDigit(c), "Peek() must have lied");
do {
exponent = 10*exponent + DecimalDigitValue(c);
c = Read();
// The IsDigit check will do the right thing even if Read() returns < 0
} while (IsDigit(c));
} else {
if (expSignChar) {
Pushback(expSignChar);
}
}
}
nsCSSTokenType type = eCSSToken_Number;
// Set mIntegerValid for all cases (except %, below) because we need
// it for the "2n" in :nth-child(2n).
aToken.mIntegerValid = false;
// Time to reassemble our number.
float value = float(sign * (intPart + fracPart));
if (gotE) {
// pow(), not powf(), because at least wince doesn't have the latter.
// And explicitly cast everything to doubles to avoid issues with
// overloaded pow() on Windows.
value *= pow(10.0, double(expSign * exponent));
} else if (!gotDot) {
// Clamp values outside of integer range.
if (sign > 0) {
aToken.mInteger = PRInt32(NS_MIN(intPart, double(PR_INT32_MAX)));
} else {
aToken.mInteger = PRInt32(NS_MAX(-intPart, double(PR_INT32_MIN)));
}
aToken.mIntegerValid = true;
}
nsString& ident = aToken.mIdent;
ident.Truncate();
// Look at character that terminated the number
if (c >= 0) {
if (StartsIdent(c, Peek())) {
if (GatherIdent(c, ident)) {
type = eCSSToken_Dimension;
}
} else if ('%' == c) {
type = eCSSToken_Percentage;
value = value / 100.0f;
aToken.mIntegerValid = false;
} else {
// Put back character that stopped numeric scan
Pushback(c);
}
}
aToken.mNumber = value;
aToken.mType = type;
return true;
}
bool
nsCSSScanner::SkipCComment()
{
for (;;) {
PRInt32 ch = Read();
if (ch < 0) break;
if (ch == '*') {
if (LookAhead('/')) {
return true;
}
}
}
REPORT_UNEXPECTED_EOF(PECommentEOF);
return false;
}
bool
nsCSSScanner::ParseString(PRInt32 aStop, nsCSSToken& aToken)
{
aToken.mIdent.SetLength(0);
aToken.mType = eCSSToken_String;
aToken.mSymbol = PRUnichar(aStop); // remember how it's quoted
for (;;) {
// If nothing in pushback, first try to get as much as possible in one go
if (!mPushbackCount && mOffset < mCount) {
// See how much we can consume and append in one go
PRUint32 n = mOffset;
// Count number of characters that can be processed
for (;n < mCount; ++n) {
PRUnichar nextChar = mReadPointer[n];
if ((nextChar == aStop) || (nextChar == '\\') ||
(nextChar == '\n') || (nextChar == '\r') || (nextChar == '\f')) {
break;
}
#ifdef CSS_REPORT_PARSE_ERRORS
++mColNumber;
#endif
}
// Add to the token what we have so far
if (n > mOffset) {
aToken.mIdent.Append(&mReadPointer[mOffset], n - mOffset);
mOffset = n;
}
}
PRInt32 ch = Read();
if (ch < 0 || ch == aStop) {
break;
}
if (ch == '\n') {
aToken.mType = eCSSToken_Bad_String;
#ifdef CSS_REPORT_PARSE_ERRORS
ReportUnexpectedToken(aToken, "SEUnterminatedString");
#endif
break;
}
if (ch == '\\') {
if (!ParseAndAppendEscape(aToken.mIdent, true)) {
aToken.mType = eCSSToken_Bad_String;
Pushback(ch);
#ifdef CSS_REPORT_PARSE_ERRORS
// For strings, the only case where ParseAndAppendEscape will
// return false is when there's a backslash to start an escape
// immediately followed by end-of-stream. In that case, the
// correct tokenization is badstring *followed* by a DELIM for
// the backslash, but as far as the author is concerned, it
// works pretty much the same as an unterminated string, so we
// use the same error message.
ReportUnexpectedToken(aToken, "SEUnterminatedString");
#endif
break;
}
} else {
aToken.mIdent.Append(ch);
}
}
return true;
}
// UNICODE-RANGE tokens match the regular expression
//
// u\+[0-9a-f?]{1,6}(-[0-9a-f]{1,6})?
//
// However, some such tokens are "invalid". There are three valid forms:
//
// u+[0-9a-f]{x} 1 <= x <= 6
// u+[0-9a-f]{x}\?{y} 1 <= x+y <= 6
// u+[0-9a-f]{x}-[0-9a-f]{y} 1 <= x <= 6, 1 <= y <= 6
//
// All unicode-range tokens have their text recorded in mIdent; valid ones
// are also decoded into mInteger and mInteger2, and mIntegerValid is set.
bool
nsCSSScanner::ParseURange(PRInt32 aChar, nsCSSToken& aResult)
{
PRInt32 intro2 = Read();
PRInt32 ch = Peek();
// We should only ever be called if these things are true.
NS_ASSERTION(aChar == 'u' || aChar == 'U',
"unicode-range called with improper introducer (U)");
NS_ASSERTION(intro2 == '+',
"unicode-range called with improper introducer (+)");
// If the character immediately after the '+' is not a hex digit or
// '?', this is not really a unicode-range token; push everything
// back and scan the U as an ident.
if (!IsHexDigit(ch) && ch != '?') {
Pushback(intro2);
Pushback(aChar);
return ParseIdent(aChar, aResult);
}
aResult.mIdent.Truncate();
aResult.mIdent.Append(aChar);
aResult.mIdent.Append(intro2);
bool valid = true;
bool haveQues = false;
PRUint32 low = 0;
PRUint32 high = 0;
int i = 0;
for (;;) {
ch = Read();
i++;
if (i == 7 || !(IsHexDigit(ch) || ch == '?')) {
break;
}
aResult.mIdent.Append(ch);
if (IsHexDigit(ch)) {
if (haveQues) {
valid = false; // all question marks should be at the end
}
low = low*16 + HexDigitValue(ch);
high = high*16 + HexDigitValue(ch);
} else {
haveQues = true;
low = low*16 + 0x0;
high = high*16 + 0xF;
}
}
if (ch == '-' && IsHexDigit(Peek())) {
if (haveQues) {
valid = false;
}
aResult.mIdent.Append(ch);
high = 0;
i = 0;
for (;;) {
ch = Read();
i++;
if (i == 7 || !IsHexDigit(ch)) {
break;
}
aResult.mIdent.Append(ch);
high = high*16 + HexDigitValue(ch);
}
}
Pushback(ch);
aResult.mInteger = low;
aResult.mInteger2 = high;
aResult.mIntegerValid = valid;
aResult.mType = eCSSToken_URange;
return true;
}
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