1324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver/* 2324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * [The "BSD license"] 3324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Copyright (c) 2010 Terence Parr 4324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * All rights reserved. 5324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 6324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Redistribution and use in source and binary forms, with or without 7324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * modification, are permitted provided that the following conditions 8324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * are met: 9324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 1. Redistributions of source code must retain the above copyright 10324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * notice, this list of conditions and the following disclaimer. 11324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 2. Redistributions in binary form must reproduce the above copyright 12324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * notice, this list of conditions and the following disclaimer in the 13324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * documentation and/or other materials provided with the distribution. 14324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 3. The name of the author may not be used to endorse or promote products 15324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * derived from this software without specific prior written permission. 16324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 17324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 28324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruverpackage org.antlr.codegen; 29324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 30324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruverimport org.antlr.analysis.*; 31324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruverimport org.antlr.misc.Utils; 32324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruverimport org.stringtemplate.v4.ST; 33324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruverimport org.stringtemplate.v4.STGroup; 34324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 35324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruverimport java.util.List; 36324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 37324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruverpublic class ACyclicDFACodeGenerator { 38324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected CodeGenerator parentGenerator; 39324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 40324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public ACyclicDFACodeGenerator(CodeGenerator parent) { 41324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver this.parentGenerator = parent; 42324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 43324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 44324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public ST genFixedLookaheadDecision(STGroup templates, 45324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver DFA dfa) 46324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 47324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return walkFixedDFAGeneratingStateMachine(templates, dfa, dfa.startState, 1); 48324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 49324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 50324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected ST walkFixedDFAGeneratingStateMachine( 51324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver STGroup templates, 52324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver DFA dfa, 53324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver DFAState s, 54324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver int k) 55324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 56324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver //System.out.println("walk "+s.stateNumber+" in dfa for decision "+dfa.decisionNumber); 57324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( s.isAcceptState() ) { 58324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver ST dfaST = templates.getInstanceOf("dfaAcceptState"); 59324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("alt", Utils.integer(s.getUniquelyPredictedAlt())); 60324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return dfaST; 61324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 62324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 63324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // the default templates for generating a state and its edges 64324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // can be an if-then-else structure or a switch 65324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver String dfaStateName = "dfaState"; 66324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver String dfaLoopbackStateName = "dfaLoopbackState"; 67324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver String dfaOptionalBlockStateName = "dfaOptionalBlockState"; 68324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver String dfaEdgeName = "dfaEdge"; 69324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( parentGenerator.canGenerateSwitch(s) ) { 70324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaStateName = "dfaStateSwitch"; 71324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaLoopbackStateName = "dfaLoopbackStateSwitch"; 72324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaOptionalBlockStateName = "dfaOptionalBlockStateSwitch"; 73324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaEdgeName = "dfaEdgeSwitch"; 74324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 75324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 76324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver ST dfaST = templates.getInstanceOf(dfaStateName); 77324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( dfa.getNFADecisionStartState().decisionStateType==NFAState.LOOPBACK ) { 78324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST = templates.getInstanceOf(dfaLoopbackStateName); 79324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 80324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver else if ( dfa.getNFADecisionStartState().decisionStateType==NFAState.OPTIONAL_BLOCK_START ) { 81324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST = templates.getInstanceOf(dfaOptionalBlockStateName); 82324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 83324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("k", Utils.integer(k)); 84324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("stateNumber", Utils.integer(s.stateNumber)); 85324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("semPredState", 86324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Boolean.valueOf(s.isResolvedWithPredicates())); 87324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /* 88324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver String description = dfa.getNFADecisionStartState().getDescription(); 89324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver description = parentGenerator.target.getTargetStringLiteralFromString(description); 90324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver //System.out.println("DFA: "+description+" associated with AST "+dfa.getNFADecisionStartState()); 91324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( description!=null ) { 92324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("description", description); 93324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 94324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 95324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver int EOTPredicts = NFA.INVALID_ALT_NUMBER; 96324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver DFAState EOTTarget = null; 97324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver //System.out.println("DFA state "+s.stateNumber); 98324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver for (int i = 0; i < s.getNumberOfTransitions(); i++) { 99324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Transition edge = (Transition) s.transition(i); 100324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver //System.out.println("edge "+s.stateNumber+"-"+edge.label.toString()+"->"+edge.target.stateNumber); 101324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( edge.label.getAtom()==Label.EOT ) { 102324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // don't generate a real edge for EOT; track alt EOT predicts 103324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // generate that prediction in the else clause as default case 104324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver EOTTarget = (DFAState)edge.target; 105324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver EOTPredicts = EOTTarget.getUniquelyPredictedAlt(); 106324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /* 107324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver System.out.println("DFA s"+s.stateNumber+" EOT goes to s"+ 108324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver edge.target.stateNumber+" predicates alt "+ 109324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver EOTPredicts); 110324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 111324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver continue; 112324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 113324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver ST edgeST = templates.getInstanceOf(dfaEdgeName); 114324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // If the template wants all the label values delineated, do that 115324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( edgeST.impl.formalArguments.get("labels")!=null ) { 116324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver List labels = edge.label.getSet().toList(); 117324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver for (int j = 0; j < labels.size(); j++) { 118324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Integer vI = (Integer) labels.get(j); 119324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver String label = 120324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver parentGenerator.getTokenTypeAsTargetLabel(vI.intValue()); 121324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver labels.set(j, label); // rewrite List element to be name 122324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 123324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver edgeST.add("labels", labels); 124324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 125324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver else { // else create an expression to evaluate (the general case) 126324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver edgeST.add("labelExpr", 127324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver parentGenerator.genLabelExpr(templates,edge,k)); 128324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 129324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 130324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // stick in any gated predicates for any edge if not already a pred 131324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( !edge.label.isSemanticPredicate() ) { 132324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver DFAState target = (DFAState)edge.target; 133324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver SemanticContext preds = 134324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver target.getGatedPredicatesInNFAConfigurations(); 135324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( preds!=null ) { 136324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver //System.out.println("preds="+target.getGatedPredicatesInNFAConfigurations()); 137324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver ST predST = preds.genExpr(parentGenerator, 138324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver parentGenerator.getTemplates(), 139324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfa); 140324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver edgeST.add("predicates", predST); 141324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 142324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 143324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 144324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver ST targetST = 145324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver walkFixedDFAGeneratingStateMachine(templates, 146324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfa, 147324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver (DFAState)edge.target, 148324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver k+1); 149324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver edgeST.add("targetState", targetST); 150324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("edges", edgeST); 151324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /* 152324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver System.out.println("back to DFA "+ 153324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfa.decisionNumber+"."+s.stateNumber); 154324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 155324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 156324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 157324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // HANDLE EOT EDGE 158324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ( EOTPredicts!=NFA.INVALID_ALT_NUMBER ) { 159324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // EOT unique predicts an alt 160324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("eotPredictsAlt", Utils.integer(EOTPredicts)); 161324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 162324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver else if ( EOTTarget!=null && EOTTarget.getNumberOfTransitions()>0 ) { 163324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // EOT state has transitions so must split on predicates. 164324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // Generate predicate else-if clauses and then generate 165324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // NoViableAlt exception as else clause. 166324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // Note: these predicates emanate from the EOT target state 167324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // rather than the current DFAState s so the error message 168324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // might be slightly misleading if you are looking at the 169324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // state number. Predicates emanating from EOT targets are 170324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // hoisted up to the state that has the EOT edge. 171324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver for (int i = 0; i < EOTTarget.getNumberOfTransitions(); i++) { 172324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Transition predEdge = (Transition)EOTTarget.transition(i); 173324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver ST edgeST = templates.getInstanceOf(dfaEdgeName); 174324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver edgeST.add("labelExpr", 175324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver parentGenerator.genSemanticPredicateExpr(templates,predEdge)); 176324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // the target must be an accept state 177324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver //System.out.println("EOT edge"); 178324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver ST targetST = 179324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver walkFixedDFAGeneratingStateMachine(templates, 180324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfa, 181324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver (DFAState)predEdge.target, 182324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver k+1); 183324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver edgeST.add("targetState", targetST); 184324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver dfaST.add("edges", edgeST); 185324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 186324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 187324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return dfaST; 188324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 189324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver} 190324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 191