got LL(1) plus loops in

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 6858]

tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg

@@ -74,9 +74,37 @@ LL1StarBlockSingleAlt(choice, expr, alts, preamble) ::= <<
 <preamble>
 while ( <expr> ) {
     <alts; separator="\n">
+    <choice.expr.nextToken.varName> = input.LA(1);
 }
 >>
 
+LL1PlusBlock(choice, alts) ::= <<
+int <choice.loopCounterVar> = 0;
+<choice.loopLabel>:
+while (true) {
+	switch ( input.LA(1) ) {
+		<choice.altLook,alts:{look,alt| <cases(ttypes=look)>
+	<alt>
+	break;}; separator="\n">
+		<cases(ttypes=choice.exitLook)>
+		    if ( <choice.loopCounterVar> >= 1 ) break <choice.loopLabel>;
+		    else error
+		default :
+		    error
+	}
+}
+>>
+
+//LL1PlusBlockSingleAlt ::= LL1PlusBlock
+
+LL1PlusBlockSingleAlt(choice, expr, alts, preamble) ::= <<
+<preamble>
+do {
+    <alts; separator="\n">
+    <choice.expr.nextToken.varName> = input.LA(1);
+} while ( <expr> );
+>>
+
 TestSet(s) ::= <<
 <s.set.name>.member(input.LA(1))
 >>

tool/src/org/antlr/v4/automata/ParserNFAFactory.java

@@ -298,6 +298,8 @@ public class ParserNFAFactory implements NFAFactory {
 		PlusBlockStartState start = (PlusBlockStartState)newState(PlusBlockStartState.class, plusAST);
 		LoopbackState loop = (LoopbackState)newState(LoopbackState.class, plusAST);
 		BlockEndState end = (BlockEndState)newState(BlockEndState.class, plusAST);
+		start.endState = end; // points past loopback state
+		start.loopBackState = loop;
 		epsilon(start, blk.left);
 		epsilon(loop, blk.left);
 		epsilon(blk.right, loop);

tool/src/org/antlr/v4/automata/PlusBlockStartState.java

@@ -1,6 +1,7 @@
 package org.antlr.v4.automata;
 
 /** */
-public class PlusBlockStartState extends BasicState {
+public class PlusBlockStartState extends BlockStartState {
+	public LoopbackState loopBackState;
 	public PlusBlockStartState(NFA nfa) { super(nfa); }
 }

tool/src/org/antlr/v4/codegen/CodeGenerator.java

@@ -3,6 +3,7 @@ package org.antlr.v4.codegen;
 import org.antlr.v4.automata.DFA;
 import org.antlr.v4.codegen.src.*;
 import org.antlr.v4.misc.IntSet;
+import org.antlr.v4.misc.IntervalSet;
 import org.antlr.v4.parse.ANTLRParser;
 import org.antlr.v4.tool.BlockAST;
 import org.antlr.v4.tool.ErrorType;
@@ -121,6 +122,8 @@ public abstract class CodeGenerator {
 				else c = new LL1StarBlock(this, ebnfRoot, alts);
 				break;
 			case ANTLRParser.POSITIVE_CLOSURE :
+				if ( alts.size()==1 ) c = new LL1PlusBlockSingleAlt(this, ebnfRoot, alts);
+				else c = new LL1PlusBlock(this, ebnfRoot, alts);
 				break;
 			default :
 				c = new LL1Choice(this, blkAST, alts);
@@ -129,6 +132,17 @@ public abstract class CodeGenerator {
 		return c;
 	}
 
+	public OutputModelObject getLL1Test(Choice choice, IntervalSet look, GrammarAST blkAST) {
+		OutputModelObject expr;
+		if ( look.size() < target.getInlineTestsVsBitsetThreshold() ) {
+			expr = new TestSetInline(this, choice, blkAST, look);
+		}
+		else {
+			expr = new TestSet(this, blkAST, look);
+		}
+		return expr;
+	}
+
 	public void write(ST code, String fileName) throws IOException {
 		long start = System.currentTimeMillis();
 		Writer w = g.tool.getOutputFile(g, fileName);
@@ -185,4 +199,12 @@ public abstract class CodeGenerator {
 		outputModel.bitSetDefs.add(b);
 		return b;
 	}
+
+	public String getLoopLabel(GrammarAST ast) {
+		return "loop"+ ast.token.getTokenIndex();
+	}
+
+	public String getLoopCounter(GrammarAST ast) {
+		return "cnt"+ ast.token.getTokenIndex();
+	}
 }

tool/src/org/antlr/v4/codegen/src/LL1OptionalBlockSingleAlt.java

@@ -13,12 +13,7 @@ public class LL1OptionalBlockSingleAlt extends LL1OptionalBlock {
 	public LL1OptionalBlockSingleAlt(CodeGenerator gen, GrammarAST blkAST, List<CodeBlock> alts) {
 		super(gen, blkAST, alts);
 		IntervalSet look = altLookSets[1];
-		if ( look.size() < gen.target.getInlineTestsVsBitsetThreshold() ) {
+		expr = gen.getLL1Test(this, look, blkAST);
-			expr = new TestSetInline(gen, this, blkAST, look);
-		}
-		else {
-			expr = new TestSet(gen, blkAST, look);
-		}
 	}
 
 	@Override

tool/src/org/antlr/v4/codegen/src/LL1PlusBlock.java

@@ -0,0 +1,28 @@
+package org.antlr.v4.codegen.src;
+
+import org.antlr.v4.automata.DFA;
+import org.antlr.v4.automata.PlusBlockStartState;
+import org.antlr.v4.codegen.CodeGenerator;
+import org.antlr.v4.misc.IntervalSet;
+import org.antlr.v4.tool.GrammarAST;
+
+import java.util.List;
+
+/** */
+public class LL1PlusBlock extends LL1Choice {
+	public String loopLabel;
+	public String loopCounterVar;
+	public String[] exitLook;
+	public LL1PlusBlock(CodeGenerator gen, GrammarAST blkAST, List<CodeBlock> alts) {
+		super(gen, blkAST, alts);
+		PlusBlockStartState plusStart = (PlusBlockStartState)blkAST.nfaState;
+		int enterExitDecision = plusStart.decision;
+
+		DFA dfa = gen.g.decisionDFAs.get(enterExitDecision);
+		IntervalSet exitLook = dfa.startState.edge(1).label;
+		this.exitLook = gen.target.getTokenTypesAsTargetLabels(gen.g, exitLook.toArray());
+
+		loopLabel = gen.getLoopLabel(blkAST);
+		loopCounterVar = gen.getLoopCounter(blkAST);
+	}
+}

tool/src/org/antlr/v4/codegen/src/LL1PlusBlockSingleAlt.java

@@ -0,0 +1,25 @@
+package org.antlr.v4.codegen.src;
+
+import org.antlr.v4.codegen.CodeGenerator;
+import org.antlr.v4.misc.IntervalSet;
+import org.antlr.v4.tool.GrammarAST;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** */
+public class LL1PlusBlockSingleAlt extends LL1Choice {
+	public Object expr;
+	public LL1PlusBlockSingleAlt(CodeGenerator gen, GrammarAST blkAST, List<CodeBlock> alts) {
+		super(gen, blkAST, alts);
+		IntervalSet loopBackLook = altLookSets[2]; // loop exit is alt 1
+		expr = gen.getLL1Test(this, loopBackLook, blkAST);
+	}
+
+	@Override
+	public List<String> getChildren() {
+		final List<String> sup = super.getChildren();
+		return new ArrayList<String>() {{ if ( sup!=null ) addAll(sup); add("expr"); }};
+	}
+	
+}

tool/src/org/antlr/v4/codegen/src/LL1StarBlock.java

@@ -25,6 +25,7 @@ public class LL1StarBlock extends LL1Choice {
 		IntervalSet exitLook = dfa.startState.edge(1).label;
 		this.exitLook = gen.target.getTokenTypesAsTargetLabels(gen.g, exitLook.toArray());
 
-		loopLabel = "loop"+blkAST.token.getTokenIndex();
+		loopLabel = gen.getLoopLabel(blkAST);
 	}
+
 }

tool/src/org/antlr/v4/codegen/src/LL1StarBlockSingleAlt.java

@@ -1,13 +1,24 @@
 package org.antlr.v4.codegen.src;
 
 import org.antlr.v4.codegen.CodeGenerator;
+import org.antlr.v4.misc.IntervalSet;
 import org.antlr.v4.tool.GrammarAST;
 
+import java.util.ArrayList;
 import java.util.List;
 
 /** */
-public class LL1StarBlockSingleAlt extends LL1OptionalBlockSingleAlt {
+public class LL1StarBlockSingleAlt extends LL1Choice {
+	public Object expr;
 	public LL1StarBlockSingleAlt(CodeGenerator gen, GrammarAST blkAST, List<CodeBlock> alts) {
 		super(gen, blkAST, alts);
+		IntervalSet look = altLookSets[1];
+		expr = gen.getLL1Test(this, look, blkAST);
+	}
+
+	@Override
+	public List<String> getChildren() {
+		final List<String> sup = super.getChildren();
+		return new ArrayList<String>() {{ if ( sup!=null ) addAll(sup); add("expr"); }};
 	}
 }