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added comments and we are now ready to build NFA, hooray! 

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 6722]
This commit is contained in:
parrt 2010-02-23 12:09:08 -08:00
parent 4fb0e7db70
commit 66ec9fa9fd
2 changed files with 46 additions and 25 deletions
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44
tool/src/org/antlr/v4/semantics/SemanticPipeline.java
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@ -2,25 +2,37 @@ package org.antlr.v4.semantics;
import org.antlr.runtime.RecognitionException;
import org.antlr.runtime.tree.BufferedTreeNodeStream;
import org.antlr.v4.analysis.Label;
import org.antlr.v4.parse.ANTLRParser;
import org.antlr.v4.parse.ASTVerifier;
import org.antlr.v4.parse.GrammarASTAdaptor;
import org.antlr.v4.tool.*;
import java.util.List;
import java.util.Map;
/** */
/** Do as much semantic checking as we can and fill in grammar
* with rules, dynamic scopes, actions, and token definitions.
* The only side effects are in the grammar pass to process().
* We consume a bunch of memory here while we build up data structures
* to perform checking, but all of it goes away after this pipeline object
* gets garbage collected.
*
* After this pipeline finishes, we can be sure that the grammar
* is syntactically correct and that it's semantically correct enough for us
* to attempt grammar analysis. We have assigned all token types.
* Note that imported grammars bring in token and rule definitions
* but only the root grammar and any implicitly created lexer grammar
* get their token definitions filled up. We are treating the
* imported grammars like includes (the generated code treats them
* as separate objects, however).
*/
public class SemanticPipeline {
public void process(Grammar g) {
if ( g.ast==null ) return;
// VALIDATE AST STRUCTURE
GrammarASTAdaptor adaptor = new GrammarASTAdaptor();
// use buffered node stream as we will look around in stream
// to give good error messages.
// TODO: send parse errors to buffer not stderr
GrammarASTAdaptor adaptor = new GrammarASTAdaptor();
BufferedTreeNodeStream nodes =
new BufferedTreeNodeStream(adaptor,g.ast);
ASTVerifier walker = new ASTVerifier(nodes);
@ -67,8 +79,8 @@ public class SemanticPipeline {
// ASSIGN TOKEN TYPES
assignTokenTypes(g, collector, symcheck);
// TODO: move to a use-def or deadcode eliminator
checkRewriteElementsPresentOnLeftSide(g, collector.rules);
UseDefAnalyzer usedef = new UseDefAnalyzer();
usedef.checkRewriteElementsPresentOnLeftSide(g, collector.rules);
}
public void assignTokenTypes(Grammar g, CollectSymbols collector, SymbolChecks symcheck) {
@ -107,22 +119,4 @@ public class SemanticPipeline {
// System.out.println("strings="+G.stringLiteralToTypeMap);
}
}
public void checkRewriteElementsPresentOnLeftSide(Grammar g, List<Rule> rules) {
for (Rule r : rules) {
for (int a=1; a<=r.numberOfAlts; a++) {
Alternative alt = r.alt[a];
for (GrammarAST e : alt.rewriteElements) {
if ( !(alt.ruleRefs.containsKey(e.getText()) ||
g.getTokenType(e.getText())!= Label.INVALID ||
alt.labelDefs.containsKey(e.getText()) ||
e.getText().equals(r.name)) ) // $r ok in rule r
{
ErrorManager.grammarError(ErrorType.REWRITE_ELEMENT_NOT_PRESENT_ON_LHS,
g.fileName, e.token, e.getText());
}
}
}
}
}
}

27
tool/src/org/antlr/v4/semantics/UseDefAnalyzer.java Normal file
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@ -0,0 +1,27 @@
package org.antlr.v4.semantics;
import org.antlr.v4.analysis.Label;
import org.antlr.v4.tool.*;
import java.util.List;
/** Look for errors and deadcode stuff */
public class UseDefAnalyzer {
public void checkRewriteElementsPresentOnLeftSide(Grammar g, List<Rule> rules) {
for (Rule r : rules) {
for (int a=1; a<=r.numberOfAlts; a++) {
Alternative alt = r.alt[a];
for (GrammarAST e : alt.rewriteElements) {
if ( !(alt.ruleRefs.containsKey(e.getText()) ||
g.getTokenType(e.getText())!= Label.INVALID ||
alt.labelDefs.containsKey(e.getText()) ||
e.getText().equals(r.name)) ) // $r ok in rule r
{
ErrorManager.grammarError(ErrorType.REWRITE_ELEMENT_NOT_PRESENT_ON_LHS,
g.fileName, e.token, e.getText());
}
}
}
}
}
}