/*******************************************************************************
* Copyright (c) 2000, 2008 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* QNX Software System
* Anton Leherbauer (Wind River Systems)
*******************************************************************************/
package org.eclipse.cdt.internal.ui.text.asm;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.rules.ICharacterScanner;
import org.eclipse.jface.text.rules.IPartitionTokenScanner;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.Token;
import org.eclipse.cdt.ui.text.ICPartitions;
import org.eclipse.cdt.internal.ui.text.BufferedDocumentScanner;
/**
* This scanner recognizes
* <ul>
* <li>C multi line comments</li>
* <li>Assembly line comments</li>
* <li>C++ line comments</li>
* <li>C string literals</li>
* <li>Assembly character literals</li>
* <li>C preprocessor directives</li>
* </ul>
* Default supported line start comment characters are ';', '!', '|' and '@'.
* <p>
* A simple heuristic is used to detect valid line end comment characters: If a
* character known to be a potential line end comment character is used as a
* line start comment char, this character is considered a valid line end
* comment character, too. If e.g. a '@' is used to introduce a line start
* comment it is also recognized as a line end comment introducer afterwards.
* </p>
*/
public final class AsmPartitionScanner implements IPartitionTokenScanner, ICPartitions {
/**
* Characters not applicable for line start comments.
*/
private static final String NON_LINE_COMMENT_CHARS = "\t #/_$.%()'\"{}"; //$NON-NLS-1$
/**
* Characters known to be used as line end comments.
*/
private static final String KNOWN_LINE_END_COMMENT_CHARS = "#;@|!"; //$NON-NLS-1$
// states
private static final int CCODE= 0;
private static final int SINGLE_LINE_COMMENT= 1;
private static final int MULTI_LINE_COMMENT= 2;
private static final int CHARACTER= 3;
private static final int STRING= 4;
private static final int PREPROCESSOR= 5;
private static final int PREPROCESSOR_MULTI_LINE_COMMENT= 6;
// beginning of prefixes and postfixes
private static final int NONE= 0;
private static final int BACKSLASH= 1; // postfix for STRING, CHARACTER and SINGLE_LINE_COMMENT
private static final int SLASH= 2; // prefix for SINGLE_LINE or MULTI_LINE
private static final int SLASH_STAR= 3; // prefix for MULTI_LINE_COMMENT
private static final int STAR= 4; // postfix for MULTI_LINE_COMMENT
private static final int CARRIAGE_RETURN=5; // postfix for STRING, CHARACTER and SINGLE_LINE_COMMENT
private static final int BACKSLASH_CR= 6; // postfix for STRING, CHARACTER and SINGLE_LINE_COMMENT
private static final int BACKSLASH_BACKSLASH= 7; // postfix for STRING, CHARACTER
/** The scanner. */
private final BufferedDocumentScanner fScanner= new BufferedDocumentScanner(1000);
/** The offset of the last returned token. */
private int fTokenOffset;
/** The length of the last returned token. */
private int fTokenLength;
/** The state of the scanner. */
private int fState;
/** The last significant character read. */
private int fLast;
/** The amount of characters already read on first call to nextToken(). */
private int fPrefixLength;
/** Indicate whether current char is first non-whitespace char on the line*/
private boolean fFirstCharOnLine= true;
private final IToken[] fTokens= new IToken[] {
new Token(null),
new Token(C_SINGLE_LINE_COMMENT),
new Token(C_MULTI_LINE_COMMENT),
new Token(C_CHARACTER),
new Token(C_STRING),
new Token(C_PREPROCESSOR),
new Token(C_MULTI_LINE_COMMENT)
};
private String fLineCommentChars= ""; //$NON-NLS-1$
private String fLineEndCommentChars= ""; //$NON-NLS-1$
private String fLineStartCommentChars= ";!|@"; //$NON-NLS-1$
private boolean fDetectPreprocessor= true;
public AsmPartitionScanner() {
}
/**
* Configure the set of default line comment characters.
* <p>
* These characters are considered line comment introducers at any position
* in the code.
* </p>
*
* @param chars
*/
public void setLineCommentCharacters(String chars) {
fLineCommentChars= chars != null ? chars : ""; //$NON-NLS-1$
}
/**
* Configure the set of default line start comment characters.
* <p>
* These characters are considered line comment introducers only as first
* non-whitespace character on the line.
* </p>
*
* @param chars
*/
public void setLineStartCommentCharacters(String chars) {
fLineStartCommentChars= chars != null ? chars : ""; //$NON-NLS-1$
}
/**
* Configure the set of default line end comment characters.
* <p>
* These characters are considered line comment introducers at the end of a
* instruction line.
* </p>
*
* @param chars
*/
public void setLineEndCommentCharacters(String chars) {
fLineEndCommentChars= chars != null ? chars : ""; //$NON-NLS-1$
}
/**
* Configure whether preprocessor directives should be detected.
*
* @param detectPreprocessor
*/
public void setDetectPreprocessorDiretives(boolean detectPreprocessor) {
fDetectPreprocessor= detectPreprocessor;
}
/*
* @see org.eclipse.jface.text.rules.ITokenScanner#nextToken()
*/
public IToken nextToken() {
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
while (true) {
final int ch= fScanner.read();
final boolean isFirstCharOnLine= fFirstCharOnLine;
if (fFirstCharOnLine && ch != ' ' && ch != '\t') {
fFirstCharOnLine= false;
}
// characters
switch (ch) {
case ICharacterScanner.EOF:
if (fTokenLength > 0) {
fLast= NONE; // ignore last
return preFix(fState, CCODE, NONE, 0);
} else {
fLast= NONE;
fPrefixLength= 0;
return Token.EOF;
}
case '\r':
fFirstCharOnLine= true;
if (fLast == BACKSLASH || fLast == BACKSLASH_BACKSLASH) {
fLast= BACKSLASH_CR;
fTokenLength++;
continue;
} else if (fLast != CARRIAGE_RETURN) {
fLast= CARRIAGE_RETURN;
fTokenLength++;
continue;
} else {
// fLast == CARRIAGE_RETURN
switch (fState) {
case SINGLE_LINE_COMMENT:
case CHARACTER:
case STRING:
case PREPROCESSOR:
if (fTokenLength > 0) {
IToken token= fTokens[fState];
fLast= CARRIAGE_RETURN;
fPrefixLength= 1;
fState= CCODE;
return token;
} else {
consume();
continue;
}
default:
consume();
continue;
}
}
case '\\':
switch (fState) {
case CHARACTER:
case STRING:
fTokenLength++;
fLast= fLast == BACKSLASH ? BACKSLASH_BACKSLASH : BACKSLASH;
continue;
default:
fTokenLength++;
fLast= BACKSLASH;
continue;
}
case '\n':
fFirstCharOnLine= true;
switch (fState) {
case SINGLE_LINE_COMMENT:
case CHARACTER:
case STRING:
case PREPROCESSOR:
// assert(fTokenLength > 0);
// if last char was a backslash then we have an escaped line
if (fLast != BACKSLASH && fLast != BACKSLASH_CR && fLast != BACKSLASH_BACKSLASH) {
return postFix(fState);
}
consume();
continue;
default:
consume();
continue;
}
case ' ':
case '\t':
consume();
continue;
default:
if (fLast == CARRIAGE_RETURN) {
switch (fState) {
case SINGLE_LINE_COMMENT:
case CHARACTER:
case STRING:
case PREPROCESSOR:
int last;
int newState;
switch (ch) {
case '/':
last= SLASH;
newState= CCODE;
break;
case '*':
last= STAR;
newState= CCODE;
break;
case '\'':
last= NONE;
newState= CHARACTER;
break;
case '"':
last= NONE;
newState= STRING;
break;
case '\r':
last= CARRIAGE_RETURN;
newState= CCODE;
break;
case '\\':
last= BACKSLASH;
newState= CCODE;
break;
case '#':
last= NONE;
newState= PREPROCESSOR;
break;
default:
last= NONE;
newState= CCODE;
break;
}
fLast= NONE; // ignore fLast
return preFix(fState, newState, last, 1);
case CCODE:
if (fDetectPreprocessor && ch == '#' && isFirstCharOnLine) {
fLast= NONE; // ignore fLast
int column= fScanner.getColumn() - 1;
fTokenLength -= column;
if (fTokenLength > 0) {
return preFix(fState, PREPROCESSOR, NONE, column + 1);
} else {
preFix(fState, PREPROCESSOR, NONE, column + 1);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
break;
}
}
break;
default:
break;
}
}
}
// states
switch (fState) {
case CCODE:
if (fLast == NONE) {
boolean isLineComment= false;
if (ch == '#' && fDetectPreprocessor && isFirstCharOnLine) {
// don't consume as line comment
} else if (fLineCommentChars.indexOf(ch) >= 0 || (isFirstCharOnLine && fLineStartCommentChars.indexOf(ch) >= 0) || (!isFirstCharOnLine && fLineEndCommentChars.indexOf(ch) >= 0)) {
isLineComment= true;
} else if (isFirstCharOnLine && !Character.isLetterOrDigit((char)ch) && NON_LINE_COMMENT_CHARS.indexOf(ch) < 0) {
fLineStartCommentChars += (char)ch;
isLineComment= true;
}
if (isLineComment) {
if (isFirstCharOnLine && fLineEndCommentChars.indexOf(ch) < 0 && KNOWN_LINE_END_COMMENT_CHARS.indexOf(ch) >= 0) {
fLineEndCommentChars += (char)ch;
}
if (fTokenLength - getLastLength(fLast) > 0) {
return preFix(CCODE, SINGLE_LINE_COMMENT, NONE, 1);
} else {
preFix(CCODE, SINGLE_LINE_COMMENT, NONE, 1);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
}
break;
}
}
switch (ch) {
case '/':
// supported by gnu preprocessor
if (fLast == SLASH) {
if (fTokenLength - getLastLength(fLast) > 0) {
return preFix(CCODE, SINGLE_LINE_COMMENT, NONE, 2);
} else {
preFix(CCODE, SINGLE_LINE_COMMENT, NONE, 2);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
break;
}
} else {
fTokenLength++;
fLast= SLASH;
break;
}
case '*':
if (fLast == SLASH) {
if (fTokenLength - getLastLength(fLast) > 0) {
return preFix(CCODE, MULTI_LINE_COMMENT, SLASH_STAR, 2);
} else {
preFix(CCODE, MULTI_LINE_COMMENT, SLASH_STAR, 2);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
break;
}
} else {
consume();
break;
}
case '\'':
fLast= NONE; // ignore fLast
if (fTokenLength > 0) {
return preFix(CCODE, CHARACTER, NONE, 1);
} else {
preFix(CCODE, CHARACTER, NONE, 1);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
break;
}
case '"':
fLast= NONE; // ignore fLast
if (fTokenLength > 0 ) {
return preFix(CCODE, STRING, NONE, 1);
} else {
preFix(CCODE, STRING, NONE, 1);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
break;
}
case '#':
if (fDetectPreprocessor && isFirstCharOnLine) {
int column= fScanner.getColumn() - 1;
fTokenLength -= column;
if (fTokenLength > 0) {
return preFix(fState, PREPROCESSOR, NONE, column + 1);
} else {
preFix(fState, PREPROCESSOR, NONE, column + 1);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
break;
}
}
consume();
break;
default:
consume();
break;
}
break;
case SINGLE_LINE_COMMENT:
consume();
break;
case PREPROCESSOR:
switch (ch) {
case '/':
if (fLast == SLASH) {
consume();
break;
} else {
fTokenLength++;
fLast= SLASH;
break;
}
case '*':
if (fLast == SLASH) {
if (fTokenLength - getLastLength(fLast) > 0) {
return preFix(fState, PREPROCESSOR_MULTI_LINE_COMMENT, SLASH_STAR, 2);
} else {
preFix(fState, PREPROCESSOR_MULTI_LINE_COMMENT, SLASH_STAR, 2);
fTokenOffset += fTokenLength;
fTokenLength= fPrefixLength;
break;
}
} else {
consume();
break;
}
default:
consume();
break;
}
break;
case PREPROCESSOR_MULTI_LINE_COMMENT:
switch (ch) {
case '*':
fTokenLength++;
fLast= STAR;
break;
case '/':
if (fLast == STAR) {
IToken token= postFix(fState);
fState= PREPROCESSOR;
return token;
}
consume();
break;
default:
consume();
break;
}
break;
case MULTI_LINE_COMMENT:
switch (ch) {
case '*':
fTokenLength++;
fLast= STAR;
break;
case '/':
if (fLast == STAR) {
return postFix(MULTI_LINE_COMMENT);
} else {
consume();
break;
}
default:
consume();
break;
}
break;
case STRING:
switch (ch) {
case '\"':
if (fLast != BACKSLASH) {
return postFix(STRING);
} else {
consume();
break;
}
default:
consume();
break;
}
break;
case CHARACTER:
switch (ch) {
case '\\':
fLast= (fLast == BACKSLASH) ? NONE : BACKSLASH;
fTokenLength++;
if (fLast != BACKSLASH) {
return preFix(CHARACTER, CCODE, NONE, 1);
}
break;
default:
return postFix(CHARACTER);
}
break;
}
}
}
private static final int getLastLength(int last) {
switch (last) {
default:
return -1;
case NONE:
return 0;
case CARRIAGE_RETURN:
case BACKSLASH:
case SLASH:
case STAR:
return 1;
case SLASH_STAR:
case BACKSLASH_CR:
case BACKSLASH_BACKSLASH:
return 2;
}
}
private final void consume() {
fTokenLength++;
fLast= NONE;
}
private final IToken postFix(int state) {
fTokenLength++;
fLast= NONE;
fState= CCODE;
fPrefixLength= 0;
return fTokens[state];
}
private final IToken preFix(int state, int newState, int last, int prefixLength) {
fTokenLength -= getLastLength(fLast);
fLast= last;
fPrefixLength= prefixLength;
IToken token= fTokens[state];
fState= newState;
return token;
}
private static int getState(String contentType) {
if (contentType == null)
return CCODE;
else if (contentType.equals(C_SINGLE_LINE_COMMENT))
return SINGLE_LINE_COMMENT;
else if (contentType.equals(C_MULTI_LINE_COMMENT))
return MULTI_LINE_COMMENT;
else if (contentType.equals(C_STRING))
return STRING;
else if (contentType.equals(C_CHARACTER))
return CHARACTER;
else if (contentType.equals(C_PREPROCESSOR))
return PREPROCESSOR;
else
return CCODE;
}
/*
* @see IPartitionTokenScanner#setPartialRange(IDocument, int, int, String, int)
*/
public void setPartialRange(IDocument document, int offset, int length, String contentType, int partitionOffset) {
fScanner.setRange(document, offset, length);
fTokenOffset= partitionOffset;
fTokenLength= 0;
fPrefixLength= offset - partitionOffset;
fLast= NONE;
if (offset == partitionOffset) {
// restart at beginning of partition
fState= CCODE;
} else {
fState= getState(contentType);
}
try {
int column= fScanner.getColumn();
fFirstCharOnLine= column == 0 || document.get(offset-column, column).trim().length() == 0;
} catch (BadLocationException exc) {
fFirstCharOnLine= true;
}
}
/*
* @see ITokenScanner#setRange(IDocument, int, int)
*/
public void setRange(IDocument document, int offset, int length) {
fScanner.setRange(document, offset, length);
fTokenOffset= offset;
fTokenLength= 0;
fPrefixLength= 0;
fLast= NONE;
fState= CCODE;
try {
int column= fScanner.getColumn();
fFirstCharOnLine= column == 0 || document.get(offset-column, column).trim().length() == 0;
} catch (BadLocationException exc) {
fFirstCharOnLine= true;
}
}
/*
* @see ITokenScanner#getTokenLength()
*/
public int getTokenLength() {
return fTokenLength;
}
/*
* @see ITokenScanner#getTokenOffset()
*/
public int getTokenOffset() {
return fTokenOffset;
}
}