adding nfa building infrastructur

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 6728]

tool/src/org/antlr/v4/Tool.java

@@ -1,10 +1,12 @@
 package org.antlr.v4;
 
 import org.antlr.runtime.*;
+import org.antlr.runtime.tree.BufferedTreeNodeStream;
 import org.antlr.runtime.tree.TreeWizard;
 import org.antlr.v4.parse.ANTLRLexer;
 import org.antlr.v4.parse.ANTLRParser;
 import org.antlr.v4.parse.GrammarASTAdaptor;
+import org.antlr.v4.parse.NFABuilder;
 import org.antlr.v4.semantics.SemanticPipeline;
 import org.antlr.v4.tool.*;
 
@@ -364,6 +366,11 @@ public class Tool {
 		}
 
 		// BUILD NFA FROM AST
+		GrammarASTAdaptor adaptor = new GrammarASTAdaptor();
+		BufferedTreeNodeStream nodes =
+			new BufferedTreeNodeStream(adaptor,g.ast);
+		NFABuilder nfaBuilder = new NFABuilder(nodes,g);
+		nfaBuilder.downup(g.ast);
 
 		// PERFORM GRAMMAR ANALYSIS ON NFA: BUILD DECISION DFAs
 

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

@@ -0,0 +1,29 @@
+package org.antlr.v4.automata;
+
+import org.antlr.runtime.RecognizerSharedState;
+import org.antlr.runtime.tree.TreeNodeStream;
+import org.antlr.v4.runtime.tree.TreeFilter;
+
+/** Superclass of NFABuilder.g that provides actual NFA construction routines. */
+public class NFAFactory extends TreeFilter {
+
+	/** A pair of states pointing to the left/right (start and end) states of a
+	 *  state submachine.  Used to build NFAs.
+	 */
+	public static class Grip {
+		public NFAState left;
+		public NFAState right;
+
+		public Grip(NFAState left, NFAState right) {
+			this.left = left;
+			this.right = right;
+		}
+	}
+
+	public NFAFactory(TreeNodeStream input) {
+		super(input);
+	}
+	public NFAFactory(TreeNodeStream input, RecognizerSharedState state) {
+		super(input, state);
+	}
+}

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

@@ -1,14 +0,0 @@
-package org.antlr.v4.automata;
-
-/** A pair of states pointing to the left/right (start and end) states of a
- *  state submachine.  Used to build NFAs.
- */
-public class StatePair {
-    public NFAState left;
-    public NFAState right;
-
-    public StatePair(NFAState left, NFAState right) {
-        this.left = left;
-        this.right = right;
-    }
-}

tool/src/org/antlr/v4/parse/NFABuilder.g

@@ -0,0 +1,185 @@
+/*
+ [The "BSD license"]
+ Copyright (c) 2010 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.
+*/
+
+tree grammar NFABuilder;
+options {
+	language     = Java;
+	tokenVocab   = ANTLRParser;
+	ASTLabelType = GrammarAST;
+	filter 	     = true;
+	superClass   = 'org.antlr.v4.automata.NFAFactory';
+}
+
+// Include the copyright in this source and also the generated source
+@header {
+/*
+ [The "BSD license"]
+ Copyright (c) 2010 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.v4.parse;
+import org.antlr.v4.tool.*;
+import org.antlr.v4.runtime.tree.CommonTree; // use updated v4 one not v3
+}
+
+@members {
+	Rule currentRule;
+    Grammar g;
+    public NFABuilder(TreeNodeStream input, Grammar g) {
+    	this(input);
+    	this.g = g;
+    }
+}
+
+// IGNORE EVERYTHING UNTIL WE SEE A RULE OR BLOCK SUBTREE
+
+topdown
+	:	rule
+	;
+
+bottomup
+	:	block // match block innermost to outermost all the way out to rule block
+	;
+
+rule:   ^(RULE name=ID .+) {currentRule = g.getRule($name.text);}
+	;
+
+block
+    :	^(BLOCK ~ALT+ alternative+)
+    ;
+
+alternative
+    :	^(ALT_REWRITE alternative .)
+    |	^(ALT EPSILON)
+    |   ^(ALT element+)
+    ;
+
+element
+	:	labeledElement
+	|	atom
+	|	ebnf
+	|   ACTION
+	|   SEMPRED
+	|	GATED_SEMPRED
+	|	treeSpec
+	;
+	
+labeledElement
+	:	^(ASSIGN ID atom)
+	|	^(ASSIGN ID block)
+	|	^(PLUS_ASSIGN ID atom)
+	|	^(PLUS_ASSIGN ID block)
+	;
+
+treeSpec
+    : ^(TREE_BEGIN element+)
+    ;
+
+ebnf:	^(blockSuffix block)
+	| 	block
+    ;
+
+blockSuffix
+    : ebnfSuffix
+    | ROOT
+    | IMPLIES
+    | BANG
+    ;
+
+ebnfSuffix
+	:	OPTIONAL
+  	|	CLOSURE
+   	|	POSITIVE_CLOSURE
+	;
+	
+atom:	^(ROOT range)
+	|	^(BANG range)
+	|	^(ROOT notSet)
+	|	^(BANG notSet)
+	|	range
+	|	^(DOT ID terminal)
+	|	^(DOT ID ruleref)
+    |   terminal
+    |   ruleref
+    ;
+
+notSet
+    : ^(NOT notTerminal)
+    | ^(NOT block)
+    ;
+
+notTerminal
+    : TOKEN_REF
+    | STRING_LITERAL
+    ;
+
+ruleref
+    :	^(ROOT ^(RULE_REF ARG_ACTION?))
+    |	^(BANG ^(RULE_REF ARG_ACTION?))
+    |	^(RULE_REF ARG_ACTION?)
+    ;
+
+range
+    : ^(RANGE rangeElement rangeElement)
+    ;
+
+rangeElement
+    : STRING_LITERAL
+    | RULE_REF
+    | TOKEN_REF
+    ;
+
+terminal
+    :  ^(STRING_LITERAL .)
+    |	STRING_LITERAL
+    |	^(TOKEN_REF ARG_ACTION .)
+    |	^(TOKEN_REF .)
+    |	TOKEN_REF
+    |	^(WILDCARD .)
+    |	WILDCARD
+    |	^(ROOT terminal)
+    |	^(BANG terminal)
+    ;