| /* |
| [The "BSD license"] |
| Copyright (c) 2005-2009 Terence Parr |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| 1. Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| 2. Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| 3. The name of the author may not be used to endorse or promote products |
| derived from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.antlr.runtime.debug; |
| |
| import org.antlr.runtime.RecognitionException; |
| import org.antlr.runtime.Token; |
| |
| /** All debugging events that a recognizer can trigger. |
| * |
| * I did not create a separate AST debugging interface as it would create |
| * lots of extra classes and DebugParser has a dbg var defined, which makes |
| * it hard to change to ASTDebugEventListener. I looked hard at this issue |
| * and it is easier to understand as one monolithic event interface for all |
| * possible events. Hopefully, adding ST debugging stuff won't be bad. Leave |
| * for future. 4/26/2006. |
| */ |
| public interface DebugEventListener { |
| /** Moved to version 2 for v3.1: added grammar name to enter/exit Rule */ |
| public static final String PROTOCOL_VERSION = "2"; |
| |
| /** serialized version of true */ |
| public static final int TRUE = 1; |
| public static final int FALSE = 0; |
| |
| /** The parser has just entered a rule. No decision has been made about |
| * which alt is predicted. This is fired AFTER init actions have been |
| * executed. Attributes are defined and available etc... |
| * The grammarFileName allows composite grammars to jump around among |
| * multiple grammar files. |
| */ |
| public void enterRule(String grammarFileName, String ruleName); |
| |
| /** Because rules can have lots of alternatives, it is very useful to |
| * know which alt you are entering. This is 1..n for n alts. |
| */ |
| public void enterAlt(int alt); |
| |
| /** This is the last thing executed before leaving a rule. It is |
| * executed even if an exception is thrown. This is triggered after |
| * error reporting and recovery have occurred (unless the exception is |
| * not caught in this rule). This implies an "exitAlt" event. |
| * The grammarFileName allows composite grammars to jump around among |
| * multiple grammar files. |
| */ |
| public void exitRule(String grammarFileName, String ruleName); |
| |
| /** Track entry into any (...) subrule other EBNF construct */ |
| public void enterSubRule(int decisionNumber); |
| |
| public void exitSubRule(int decisionNumber); |
| |
| /** Every decision, fixed k or arbitrary, has an enter/exit event |
| * so that a GUI can easily track what LT/consume events are |
| * associated with prediction. You will see a single enter/exit |
| * subrule but multiple enter/exit decision events, one for each |
| * loop iteration. |
| */ |
| public void enterDecision(int decisionNumber, boolean couldBacktrack); |
| |
| public void exitDecision(int decisionNumber); |
| |
| /** An input token was consumed; matched by any kind of element. |
| * Trigger after the token was matched by things like match(), matchAny(). |
| */ |
| public void consumeToken(Token t); |
| |
| /** An off-channel input token was consumed. |
| * Trigger after the token was matched by things like match(), matchAny(). |
| * (unless of course the hidden token is first stuff in the input stream). |
| */ |
| public void consumeHiddenToken(Token t); |
| |
| /** Somebody (anybody) looked ahead. Note that this actually gets |
| * triggered by both LA and LT calls. The debugger will want to know |
| * which Token object was examined. Like consumeToken, this indicates |
| * what token was seen at that depth. A remote debugger cannot look |
| * ahead into a file it doesn't have so LT events must pass the token |
| * even if the info is redundant. |
| */ |
| public void LT(int i, Token t); |
| |
| /** The parser is going to look arbitrarily ahead; mark this location, |
| * the token stream's marker is sent in case you need it. |
| */ |
| public void mark(int marker); |
| |
| /** After an arbitrairly long lookahead as with a cyclic DFA (or with |
| * any backtrack), this informs the debugger that stream should be |
| * rewound to the position associated with marker. |
| */ |
| public void rewind(int marker); |
| |
| /** Rewind to the input position of the last marker. |
| * Used currently only after a cyclic DFA and just |
| * before starting a sem/syn predicate to get the |
| * input position back to the start of the decision. |
| * Do not "pop" the marker off the state. mark(i) |
| * and rewind(i) should balance still. |
| */ |
| public void rewind(); |
| |
| public void beginBacktrack(int level); |
| |
| public void endBacktrack(int level, boolean successful); |
| |
| /** To watch a parser move through the grammar, the parser needs to |
| * inform the debugger what line/charPos it is passing in the grammar. |
| * For now, this does not know how to switch from one grammar to the |
| * other and back for island grammars etc... |
| * |
| * This should also allow breakpoints because the debugger can stop |
| * the parser whenever it hits this line/pos. |
| */ |
| public void location(int line, int pos); |
| |
| /** A recognition exception occurred such as NoViableAltException. I made |
| * this a generic event so that I can alter the exception hierachy later |
| * without having to alter all the debug objects. |
| * |
| * Upon error, the stack of enter rule/subrule must be properly unwound. |
| * If no viable alt occurs it is within an enter/exit decision, which |
| * also must be rewound. Even the rewind for each mark must be unwount. |
| * In the Java target this is pretty easy using try/finally, if a bit |
| * ugly in the generated code. The rewind is generated in DFA.predict() |
| * actually so no code needs to be generated for that. For languages |
| * w/o this "finally" feature (C++?), the target implementor will have |
| * to build an event stack or something. |
| * |
| * Across a socket for remote debugging, only the RecognitionException |
| * data fields are transmitted. The token object or whatever that |
| * caused the problem was the last object referenced by LT. The |
| * immediately preceding LT event should hold the unexpected Token or |
| * char. |
| * |
| * Here is a sample event trace for grammar: |
| * |
| * b : C ({;}A|B) // {;} is there to prevent A|B becoming a set |
| * | D |
| * ; |
| * |
| * The sequence for this rule (with no viable alt in the subrule) for |
| * input 'c c' (there are 3 tokens) is: |
| * |
| * commence |
| * LT(1) |
| * enterRule b |
| * location 7 1 |
| * enter decision 3 |
| * LT(1) |
| * exit decision 3 |
| * enterAlt1 |
| * location 7 5 |
| * LT(1) |
| * consumeToken [c/<4>,1:0] |
| * location 7 7 |
| * enterSubRule 2 |
| * enter decision 2 |
| * LT(1) |
| * LT(1) |
| * recognitionException NoViableAltException 2 1 2 |
| * exit decision 2 |
| * exitSubRule 2 |
| * beginResync |
| * LT(1) |
| * consumeToken [c/<4>,1:1] |
| * LT(1) |
| * endResync |
| * LT(-1) |
| * exitRule b |
| * terminate |
| */ |
| public void recognitionException(RecognitionException e); |
| |
| /** Indicates the recognizer is about to consume tokens to resynchronize |
| * the parser. Any consume events from here until the recovered event |
| * are not part of the parse--they are dead tokens. |
| */ |
| public void beginResync(); |
| |
| /** Indicates that the recognizer has finished consuming tokens in order |
| * to resychronize. There may be multiple beginResync/endResync pairs |
| * before the recognizer comes out of errorRecovery mode (in which |
| * multiple errors are suppressed). This will be useful |
| * in a gui where you want to probably grey out tokens that are consumed |
| * but not matched to anything in grammar. Anything between |
| * a beginResync/endResync pair was tossed out by the parser. |
| */ |
| public void endResync(); |
| |
| /** A semantic predicate was evaluate with this result and action text */ |
| public void semanticPredicate(boolean result, String predicate); |
| |
| /** Announce that parsing has begun. Not technically useful except for |
| * sending events over a socket. A GUI for example will launch a thread |
| * to connect and communicate with a remote parser. The thread will want |
| * to notify the GUI when a connection is made. ANTLR parsers |
| * trigger this upon entry to the first rule (the ruleLevel is used to |
| * figure this out). |
| */ |
| public void commence(); |
| |
| /** Parsing is over; successfully or not. Mostly useful for telling |
| * remote debugging listeners that it's time to quit. When the rule |
| * invocation level goes to zero at the end of a rule, we are done |
| * parsing. |
| */ |
| public void terminate(); |
| |
| |
| // T r e e P a r s i n g |
| |
| /** Input for a tree parser is an AST, but we know nothing for sure |
| * about a node except its type and text (obtained from the adaptor). |
| * This is the analog of the consumeToken method. Again, the ID is |
| * the hashCode usually of the node so it only works if hashCode is |
| * not implemented. If the type is UP or DOWN, then |
| * the ID is not really meaningful as it's fixed--there is |
| * just one UP node and one DOWN navigation node. |
| * @param t |
| */ |
| public void consumeNode(Object t); |
| |
| /** The tree parser lookedahead. If the type is UP or DOWN, |
| * then the ID is not really meaningful as it's fixed--there is |
| * just one UP node and one DOWN navigation node. |
| */ |
| public void LT(int i, Object t); |
| |
| |
| // A S T E v e n t s |
| |
| /** A nil was created (even nil nodes have a unique ID... |
| * they are not "null" per se). As of 4/28/2006, this |
| * seems to be uniquely triggered when starting a new subtree |
| * such as when entering a subrule in automatic mode and when |
| * building a tree in rewrite mode. |
| * |
| * If you are receiving this event over a socket via |
| * RemoteDebugEventSocketListener then only t.ID is set. |
| */ |
| public void nilNode(Object t); |
| |
| /** Upon syntax error, recognizers bracket the error with an error node |
| * if they are building ASTs. |
| * @param t |
| */ |
| public void errorNode(Object t); |
| |
| /** Announce a new node built from token elements such as type etc... |
| * |
| * If you are receiving this event over a socket via |
| * RemoteDebugEventSocketListener then only t.ID, type, text are |
| * set. |
| */ |
| public void createNode(Object t); |
| |
| /** Announce a new node built from an existing token. |
| * |
| * If you are receiving this event over a socket via |
| * RemoteDebugEventSocketListener then only node.ID and token.tokenIndex |
| * are set. |
| */ |
| public void createNode(Object node, Token token); |
| |
| /** Make a node the new root of an existing root. See |
| * |
| * Note: the newRootID parameter is possibly different |
| * than the TreeAdaptor.becomeRoot() newRoot parameter. |
| * In our case, it will always be the result of calling |
| * TreeAdaptor.becomeRoot() and not root_n or whatever. |
| * |
| * The listener should assume that this event occurs |
| * only when the current subrule (or rule) subtree is |
| * being reset to newRootID. |
| * |
| * If you are receiving this event over a socket via |
| * RemoteDebugEventSocketListener then only IDs are set. |
| * |
| * @see org.antlr.runtime.tree.TreeAdaptor.becomeRoot() |
| */ |
| public void becomeRoot(Object newRoot, Object oldRoot); |
| |
| /** Make childID a child of rootID. |
| * |
| * If you are receiving this event over a socket via |
| * RemoteDebugEventSocketListener then only IDs are set. |
| * |
| * @see org.antlr.runtime.tree.TreeAdaptor.addChild() |
| */ |
| public void addChild(Object root, Object child); |
| |
| /** Set the token start/stop token index for a subtree root or node. |
| * |
| * If you are receiving this event over a socket via |
| * RemoteDebugEventSocketListener then only t.ID is set. |
| */ |
| public void setTokenBoundaries(Object t, int tokenStartIndex, int tokenStopIndex); |
| } |