protected void checkPrediction(DFA dfa, string input, int expected)
//throws Exception
{
ANTLRStringStream stream = new ANTLRStringStream(input);
assertEquals(dfa.Predict(stream), expected);
}
public void TestFiniteCommonLeftPrefixes() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : 'a' 'b' | 'a' 'c' | 'd' 'e' ;");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(1);
checkPrediction(dfa, "ab", 1);
checkPrediction(dfa, "ac", 2);
checkPrediction(dfa, "de", 3);
checkPrediction(dfa, "q", NFA.INVALID_ALT_NUMBER);
}
public void TestSimpleAltCharTest() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : {;}'a' | 'b' | 'c';");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(1);
checkPrediction(dfa, "a", 1);
checkPrediction(dfa, "b", 2);
checkPrediction(dfa, "c", 3);
checkPrediction(dfa, "d", NFA.INVALID_ALT_NUMBER);
}
public void TestSimpleLoops() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : (DIGIT)+ '.' DIGIT | (DIGIT)+ ;\n" +
"fragment DIGIT : '0'..'9' ;\n");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(3);
checkPrediction(dfa, "32", 2);
checkPrediction(dfa, "999.2", 1);
checkPrediction(dfa, ".2", NFA.INVALID_ALT_NUMBER);
}
public void TestSets() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : {;}'a'..'z' | ';' | '0'..'9' ;");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(1);
checkPrediction(dfa, "a", 1);
checkPrediction(dfa, "q", 1);
checkPrediction(dfa, "z", 1);
checkPrediction(dfa, ";", 2);
checkPrediction(dfa, "9", 3);
}
public void TestLexerDelegatorRuleOverridesDelegateLeavingNoRules() /*throws Exception*/
{
// M.Tokens has nothing to predict tokens from S. Should
// not include S.Tokens alt in this case?
string slave =
"lexer grammar S;\n" +
"A : 'a' {System.out.println(\"S.A\");} ;\n";
mkdir(tmpdir);
writeFile(tmpdir, "S.g", slave);
string master =
"lexer grammar M;\n" +
"import S;\n" +
"A : 'a' {System.out.println(\"M.A\");} ;\n" +
"WS : (' '|'\\n') {skip();} ;\n";
writeFile(tmpdir, "M.g", master);
ErrorQueue equeue = new ErrorQueue();
ErrorManager.SetErrorListener(equeue);
AntlrTool antlr = newTool(new string[] { "-lib", tmpdir });
CompositeGrammar composite = new CompositeGrammar();
Grammar g = new Grammar(antlr, tmpdir + "/M.g", composite);
composite.SetDelegationRoot(g);
g.ParseAndBuildAST();
composite.AssignTokenTypes();
composite.DefineGrammarSymbols();
composite.CreateNFAs();
g.CreateLookaheadDFAs(false);
// predict only alts from M not S
string expectingDFA =
".s0-'a'->.s1\n" +
".s0-{'\\n', ' '}->:s3=>2\n" +
".s1-<EOT>->:s2=>1\n";
Antlr3.Analysis.DFA dfa = g.GetLookaheadDFA(1);
FASerializer serializer = new FASerializer(g);
string result = serializer.Serialize(dfa.startState);
assertEquals(expectingDFA, result);
// must not be a "unreachable alt: Tokens" error
assertEquals("unexpected errors: " + equeue, 0, equeue.errors.Count);
}
protected void checkDecision(Grammar g,
int decision,
string expecting,
int[] expectingUnreachableAlts)
//throws Exception
{
Antlr3.AntlrTool tool = new Antlr3.AntlrTool();
// mimic actions of org.antlr.Tool first time for grammar g
if (g.CodeGenerator == null)
{
CodeGenerator generator = new CodeGenerator(tool, g, "Java");
g.CodeGenerator = generator;
g.BuildNFA();
g.CreateLookaheadDFAs(false);
}
DFA dfa = g.GetLookaheadDFA(decision);
assertNotNull("unknown decision #" + decision, dfa);
FASerializer serializer = new FASerializer(g);
string result = serializer.Serialize(dfa.startState);
//System.out.print(result);
var nonDetAlts = dfa.UnreachableAlts;
//System.out.println("alts w/o predict state="+nonDetAlts);
// first make sure nondeterministic alts are as expected
if (expectingUnreachableAlts == null)
{
if (nonDetAlts != null && nonDetAlts.Count != 0)
{
Console.Error.WriteLine("nondeterministic alts (should be empty): " + ((IList)nonDetAlts).ToElementString());
}
assertEquals("unreachable alts mismatch", 0, nonDetAlts != null ? nonDetAlts.Count : 0);
}
else
{
for (int i = 0; i < expectingUnreachableAlts.Length; i++)
{
assertTrue("unreachable alts mismatch",
nonDetAlts != null ? nonDetAlts.Contains(expectingUnreachableAlts[i]) : false);
}
}
assertEquals(expecting, result);
}
public void TestLeftRecursivePred() /*throws Exception*/
{
// No analysis possible. but probably good to fail. Not sure we really want
// left-recursion even if guarded with pred.
Grammar g = new Grammar(
"parser grammar P;\n" +
"s : a ;\n" +
"a : {p1}? a | ID ;\n");
DecisionProbe.verbose = true; // make sure we get all error info
ErrorQueue equeue = new ErrorQueue();
ErrorManager.SetErrorListener(equeue);
CodeGenerator generator = new CodeGenerator(newTool(), g, "Java");
g.CodeGenerator = generator;
if (g.NumberOfDecisions == 0)
{
g.BuildNFA();
g.CreateLookaheadDFAs(false);
}
DFA dfa = g.GetLookaheadDFA(1);
assertEquals(null, dfa); // can't analyze.
/*
* String expecting =
* ".s0-ID->.s1\n" +
* ".s1-{p1}?->:s2=>1\n" +
* ".s1-{true}?->:s3=>2\n";
* String result = serializer.serialize(dfa.startState);
* assertEquals(expecting, result);
*/
assertEquals("unexpected number of expected problems", 1, equeue.size());
Message msg = equeue.errors[0];
assertTrue("warning must be a left recursion msg",
msg is LeftRecursionCyclesMessage);
}
public void TestLoopsWithOptimizedOutExitBranches() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : 'x'* ~'x'+ ;\n");
string expecting =
".s0-'x'->:s1=>1\n" +
".s0-{'\\u0000'..'w', 'y'..'\\uFFFF'}->:s2=>2\n";
checkDecision(g, 1, expecting, null);
// The optimizer yanks out all exit branches from EBNF blocks
// This is ok because we've already verified there are no problems
// with the enter/exit decision
DFAOptimizer optimizer = new DFAOptimizer(g);
optimizer.Optimize();
FASerializer serializer = new FASerializer(g);
DFA dfa = g.GetLookaheadDFA(1);
string result = serializer.Serialize(dfa.startState);
expecting = ".s0-'x'->:s1=>1\n";
assertEquals(expecting, result);
}
protected void checkDecision(Grammar g,
int decision,
string expecting,
int[] expectingUnreachableAlts,
int[] expectingNonDetAlts,
string expectingAmbigInput,
int[] expectingInsufficientPredAlts,
int[] expectingDanglingAlts,
int expectingNumWarnings,
bool hasPredHiddenByAction)
//throws Exception
{
DecisionProbe.verbose = true; // make sure we get all error info
ErrorQueue equeue = new ErrorQueue();
ErrorManager.SetErrorListener(equeue);
CodeGenerator generator = new CodeGenerator(newTool(), g, "Java");
g.CodeGenerator = generator;
// mimic actions of org.antlr.Tool first time for grammar g
if (g.NumberOfDecisions == 0)
{
g.BuildNFA();
g.CreateLookaheadDFAs(false);
}
if (equeue.size() != expectingNumWarnings)
{
Console.Error.WriteLine("Warnings issued: " + equeue);
}
Assert.AreEqual(expectingNumWarnings, equeue.size(), "unexpected number of expected problems");
DFA dfa = g.GetLookaheadDFA(decision);
FASerializer serializer = new FASerializer(g);
string result = serializer.Serialize(dfa.StartState);
//System.out.print(result);
var unreachableAlts = dfa.UnreachableAlts;
// make sure unreachable alts are as expected
if (expectingUnreachableAlts != null)
{
BitSet s = new BitSet();
s.AddAll(expectingUnreachableAlts);
BitSet s2 = new BitSet();
s2.AddAll(unreachableAlts);
Assert.AreEqual(s, s2, "unreachable alts mismatch");
}
else
{
Assert.AreEqual(0, unreachableAlts != null ? unreachableAlts.Count : 0, "unreachable alts mismatch");
}
// check conflicting input
if (expectingAmbigInput != null)
{
// first, find nondet message
Message msg = getNonDeterminismMessage(equeue.warnings);
Assert.IsNotNull(msg, "no nondeterminism warning?");
Assert.IsTrue(msg is GrammarNonDeterminismMessage, "expecting nondeterminism; found " + msg.GetType().Name);
GrammarNonDeterminismMessage nondetMsg =
getNonDeterminismMessage(equeue.warnings);
var labels =
nondetMsg.probe.GetSampleNonDeterministicInputSequence(nondetMsg.problemState);
string input = nondetMsg.probe.GetInputSequenceDisplay(labels);
Assert.AreEqual(expectingAmbigInput, input);
}
// check nondet alts
if (expectingNonDetAlts != null)
{
GrammarNonDeterminismMessage nondetMsg =
getNonDeterminismMessage(equeue.warnings);
Assert.IsNotNull(nondetMsg, "found no nondet alts; expecting: " + str(expectingNonDetAlts));
var nonDetAlts =
nondetMsg.probe.GetNonDeterministicAltsForState(nondetMsg.problemState);
// compare nonDetAlts with expectingNonDetAlts
BitSet s = new BitSet();
s.AddAll(expectingNonDetAlts);
BitSet s2 = new BitSet();
s2.AddAll(nonDetAlts);
Assert.AreEqual(s, s2, "nondet alts mismatch");
Assert.AreEqual(hasPredHiddenByAction, nondetMsg.problemState.Dfa.HasPredicateBlockedByAction, "mismatch between expected hasPredHiddenByAction");
}
else
{
// not expecting any nondet alts, make sure there are none
GrammarNonDeterminismMessage nondetMsg =
getNonDeterminismMessage(equeue.warnings);
Assert.IsNull(nondetMsg, "found nondet alts, but expecting none");
}
if (expectingInsufficientPredAlts != null)
{
GrammarInsufficientPredicatesMessage insuffPredMsg =
getGrammarInsufficientPredicatesMessage(equeue.warnings);
Assert.IsNotNull(insuffPredMsg, "found no GrammarInsufficientPredicatesMessage alts; expecting: " + str(expectingNonDetAlts));
var locations = insuffPredMsg.altToLocations;
var actualAlts = locations.Keys;
BitSet s = new BitSet();
s.AddAll(expectingInsufficientPredAlts);
BitSet s2 = new BitSet();
s2.AddAll(actualAlts);
Assert.AreEqual(s, s2, "mismatch between insufficiently covered alts");
Assert.AreEqual(hasPredHiddenByAction, insuffPredMsg.problemState.Dfa.HasPredicateBlockedByAction, "mismatch between expected hasPredHiddenByAction");
}
else
{
// not expecting any nondet alts, make sure there are none
GrammarInsufficientPredicatesMessage nondetMsg =
getGrammarInsufficientPredicatesMessage(equeue.warnings);
if (nondetMsg != null)
{
Console.Out.WriteLine(equeue.warnings);
}
Assert.IsNull(nondetMsg, "found insufficiently covered alts, but expecting none");
}
Assert.AreEqual(expecting, result);
}
//throws Exception
protected void checkPrediction( DFA dfa, string input, int expected )
{
ANTLRStringStream stream = new ANTLRStringStream( input );
assertEquals( dfa.Predict( stream ), expected );
}