public static IList <MatchInfo> genFirstSet(IList <MatchInfo> partialMatches, Expansion exp)
{
if (exp is RegularExpression)
{
IList <MatchInfo> retval = new List <MatchInfo>();
for (int i = 0; i < partialMatches.Count; i++)
{
MatchInfo m = (MatchInfo)partialMatches[i];
MatchInfo mnew = new MatchInfo();
for (int j = 0; j < m.firstFreeLoc; j++)
{
mnew.match[j] = m.match[j];
}
mnew.firstFreeLoc = m.firstFreeLoc;
mnew.match[mnew.firstFreeLoc++] = ((RegularExpression)exp).Ordinal;
if (mnew.firstFreeLoc == MatchInfo.laLimit)
{
sizeLimitedMatches.Add(mnew);
}
else
{
retval.Add(mnew);
}
}
return(retval);
}
else if (exp is NonTerminal)
{
NormalProduction prod = ((NonTerminal)exp).Production;
if (prod is CodeProduction)
{
return(new List <MatchInfo>());
}
else
{
return(genFirstSet(partialMatches, prod.Expansion));
}
}
else if (exp is Choice)
{
IList <MatchInfo> retval = new List <MatchInfo>();
Choice ch = (Choice)exp;
foreach (Expansion e in ch.Choices)
{
IList <MatchInfo> v = genFirstSet(partialMatches, e);
listAppend(retval, v);
}
return(retval);
}
else if (exp is Sequence)
{
IList <MatchInfo> v = partialMatches;
Sequence seq = (Sequence)exp;
foreach (Expansion unit in seq.Units)
{
v = genFirstSet(v, unit);
if (v.Count == 0)
{
break;
}
}
return(v);
}
else if (exp is OneOrMore)
{
IList <MatchInfo> retval = new List <MatchInfo>();
IList <MatchInfo> v = partialMatches;
OneOrMore om = (OneOrMore)exp;
while (true)
{
v = genFirstSet(v, om.Expansion);
if (v.Count == 0)
{
break;
}
listAppend(retval, v);
}
return(retval);
}
else if (exp is ZeroOrMore)
{
IList <MatchInfo> retval = new List <MatchInfo>();
listAppend(retval, partialMatches);
IList <MatchInfo> v = partialMatches;
ZeroOrMore zm = (ZeroOrMore)exp;
while (true)
{
v = genFirstSet(v, zm.Expansion);
if (v.Count == 0)
{
break;
}
listAppend(retval, v);
}
return(retval);
}
else if (exp is ZeroOrOne)
{
IList <MatchInfo> retval = new List <MatchInfo>();
listAppend(retval, partialMatches);
listAppend(retval, genFirstSet(partialMatches, ((ZeroOrOne)exp).Expansion));
return(retval);
}
else if (exp is TryBlock)
{
return(genFirstSet(partialMatches, ((TryBlock)exp).Expansion));
}
else if (considerSemanticLA &&
exp is Lookahead &&
((Lookahead)exp).ActionTokens.Count != 0
)
{
return(new List <MatchInfo>());
}
else
{
IList <MatchInfo> retval = new List <MatchInfo>();
listAppend(retval, partialMatches);
return(retval);
}
}
private static String image(MatchInfo m)
{
String ret = "";
for (int i = 0; i < m.firstFreeLoc; i++) {
if (m.match[i] == 0) {
ret += " <EOF>";
} else {
RegularExpression re = (RegularExpression) CSharpCCGlobals.rexps_of_tokens[m.match[i]];
if (re is RStringLiteral) {
ret += " \"" + CSharpCCGlobals.AddEscapes(((RStringLiteral) re).Image) + "\"";
} else if (re.Label != null && !re.Label.Equals("")) {
ret += " <" + re.Label + ">";
} else {
ret += " <token of kind " + i + ">";
}
}
}
if (m.firstFreeLoc == 0) {
return "";
} else {
return ret.Substring(1);
}
}
public static void choiceCalc(Choice choice)
{
int first = firstChoice(choice);
// dbl[i] and dbr[i] are lists of size limited matches for choice i
// of choice. dbl ignores matches with semantic lookaheads (when force_la_check
// is false), while dbr ignores semantic lookahead.
IList<MatchInfo>[] dbl = new IList<MatchInfo>[choice.Choices.Count];
IList<MatchInfo>[] dbr = new IList<MatchInfo>[choice.Choices.Count];
int[] minLA = new int[choice.Choices.Count - 1];
MatchInfo[] overlapInfo = new MatchInfo[choice.Choices.Count - 1];
int[] other = new int[choice.Choices.Count - 1];
MatchInfo m;
IList<MatchInfo> v;
bool overlapDetected;
for (int la = 1; la <= Options.getChoiceAmbiguityCheck(); la++) {
MatchInfo.laLimit = la;
LookaheadWalk.considerSemanticLA = !Options.getForceLaCheck();
for (int i = first; i < choice.Choices.Count - 1; i++) {
LookaheadWalk.sizeLimitedMatches = new List<MatchInfo>();
m = new MatchInfo();
m.firstFreeLoc = 0;
v = new List<MatchInfo>();
v.Add(m);
LookaheadWalk.genFirstSet(v, (Expansion) choice.Choices[i]);
dbl[i] = LookaheadWalk.sizeLimitedMatches;
}
LookaheadWalk.considerSemanticLA = false;
for (int i = first + 1; i < choice.Choices.Count; i++) {
LookaheadWalk.sizeLimitedMatches = new List<MatchInfo>();
m = new MatchInfo();
m.firstFreeLoc = 0;
v = new List<MatchInfo>();
v.Add(m);
LookaheadWalk.genFirstSet(v, (Expansion) choice.Choices[i]);
dbr[i] = LookaheadWalk.sizeLimitedMatches;
}
if (la == 1) {
for (int i = first; i < choice.Choices.Count - 1; i++) {
Expansion exp = (Expansion) choice.Choices[i];
if (Semanticize.EmptyExpansionExists(exp)) {
CSharpCCErrors.Warning(exp,
"This choice can expand to the empty token sequence " +
"and will therefore always be taken in favor of the choices appearing later.");
break;
} else if (CodeCheck(dbl[i])) {
CSharpCCErrors.Warning(exp,
"CSHARPCODE non-terminal will force this choice to be taken " +
"in favor of the choices appearing later.");
break;
}
}
}
overlapDetected = false;
for (int i = first; i < choice.Choices.Count - 1; i++) {
for (int j = i + 1; j < choice.Choices.Count; j++) {
if ((m = overlap(dbl[i], dbr[j])) != null) {
minLA[i] = la + 1;
overlapInfo[i] = m;
other[i] = j;
overlapDetected = true;
break;
}
}
}
if (!overlapDetected) {
break;
}
}
for (int i = first; i < choice.Choices.Count - 1; i++) {
if (explicitLA((Expansion) choice.Choices[i]) && !Options.getForceLaCheck()) {
continue;
}
if (minLA[i] > Options.getChoiceAmbiguityCheck()) {
CSharpCCErrors.Warning("Choice conflict involving two expansions at");
Console.Error.Write(" line " + ((Expansion) choice.Choices[i]).Line);
Console.Error.Write(", column " + ((Expansion) choice.Choices[i]).Column);
Console.Error.Write(" and line " + ((Expansion) choice.Choices[other[i]]).Line);
Console.Error.Write(", column " + ((Expansion) choice.Choices[other[i]]).Column);
Console.Error.WriteLine(" respectively.");
Console.Error.WriteLine(" A common prefix is: " + image(overlapInfo[i]));
Console.Error.WriteLine(" Consider using a lookahead of " + minLA[i] + " or more for earlier expansion.");
} else if (minLA[i] > 1) {
CSharpCCErrors.Warning("Choice conflict involving two expansions at");
Console.Error.Write(" line " + ((Expansion) choice.Choices[i]).Line);
Console.Error.Write(", column " + ((Expansion) choice.Choices[i]).Column);
Console.Error.Write(" and line " + ((Expansion) choice.Choices[other[i]]).Line);
Console.Error.Write(", column " + ((Expansion) choice.Choices[other[i]]).Column);
Console.Error.WriteLine(" respectively.");
Console.Error.WriteLine(" A common prefix is: " + image(overlapInfo[i]));
Console.Error.WriteLine(" Consider using a lookahead of " + minLA[i] + " for earlier expansion.");
}
}
}
public static void ebnfCalc(Expansion exp, Expansion nested)
{
// exp is one of OneOrMore, ZeroOrMore, ZeroOrOne
MatchInfo m, m1 = null;
IList<MatchInfo> v, first, follow;
int la;
for (la = 1; la <= Options.getOtherAmbiguityCheck(); la++) {
MatchInfo.laLimit = la;
LookaheadWalk.sizeLimitedMatches = new List<MatchInfo>();
m = new MatchInfo();
m.firstFreeLoc = 0;
v = new List<MatchInfo>();
v.Add(m);
LookaheadWalk.considerSemanticLA = !Options.getForceLaCheck();
LookaheadWalk.genFirstSet(v, nested);
first = LookaheadWalk.sizeLimitedMatches;
LookaheadWalk.sizeLimitedMatches = new List<MatchInfo>();
LookaheadWalk.considerSemanticLA = false;
LookaheadWalk.genFollowSet(v, exp, Expansion.NextGenerationIndex++);
follow = LookaheadWalk.sizeLimitedMatches;
if (la == 1) {
if (CodeCheck(first)) {
CSharpCCErrors.Warning(nested,
"CSHARPCODE non-terminal within " + image(exp) +
" construct will force this construct to be entered in favor of " +
"expansions occurring after construct.");
}
}
if ((m = overlap(first, follow)) == null) {
break;
}
m1 = m;
}
if (la > Options.getOtherAmbiguityCheck()) {
CSharpCCErrors.Warning("Choice conflict in " + image(exp) + " construct " +
"at line " + exp.Line + ", column " + exp.Column + ".");
Console.Error.WriteLine(" Expansion nested within construct and expansion following construct");
Console.Error.WriteLine(" have common prefixes, one of which is: " + image(m1));
Console.Error.WriteLine(" Consider using a lookahead of " + la + " or more for nested expansion.");
} else if (la > 1) {
CSharpCCErrors.Warning("Choice conflict in " + image(exp) + " construct " +
"at line " + exp.Line + ", column " + exp.Column + ".");
Console.Error.WriteLine(" Expansion nested within construct and expansion following construct");
Console.Error.WriteLine(" have common prefixes, one of which is: " + image(m1));
Console.Error.WriteLine(" Consider using a lookahead of " + la + " for nested expansion.");
}
}
public static void choiceCalc(Choice choice)
{
int first = firstChoice(choice);
// dbl[i] and dbr[i] are lists of size limited matches for choice i
// of choice. dbl ignores matches with semantic lookaheads (when force_la_check
// is false), while dbr ignores semantic lookahead.
IList <MatchInfo>[] dbl = new IList <MatchInfo> [choice.Choices.Count];
IList <MatchInfo>[] dbr = new IList <MatchInfo> [choice.Choices.Count];
int[] minLA = new int[choice.Choices.Count - 1];
MatchInfo[] overlapInfo = new MatchInfo[choice.Choices.Count - 1];
int[] other = new int[choice.Choices.Count - 1];
MatchInfo m;
IList <MatchInfo> v;
bool overlapDetected;
for (int la = 1; la <= Options.getChoiceAmbiguityCheck(); la++)
{
MatchInfo.laLimit = la;
LookaheadWalk.considerSemanticLA = !Options.getForceLaCheck();
for (int i = first; i < choice.Choices.Count - 1; i++)
{
LookaheadWalk.sizeLimitedMatches = new List <MatchInfo>();
m = new MatchInfo();
m.firstFreeLoc = 0;
v = new List <MatchInfo>();
v.Add(m);
LookaheadWalk.genFirstSet(v, (Expansion)choice.Choices[i]);
dbl[i] = LookaheadWalk.sizeLimitedMatches;
}
LookaheadWalk.considerSemanticLA = false;
for (int i = first + 1; i < choice.Choices.Count; i++)
{
LookaheadWalk.sizeLimitedMatches = new List <MatchInfo>();
m = new MatchInfo();
m.firstFreeLoc = 0;
v = new List <MatchInfo>();
v.Add(m);
LookaheadWalk.genFirstSet(v, (Expansion)choice.Choices[i]);
dbr[i] = LookaheadWalk.sizeLimitedMatches;
}
if (la == 1)
{
for (int i = first; i < choice.Choices.Count - 1; i++)
{
Expansion exp = (Expansion)choice.Choices[i];
if (Semanticize.EmptyExpansionExists(exp))
{
CSharpCCErrors.Warning(exp,
"This choice can expand to the empty token sequence " +
"and will therefore always be taken in favor of the choices appearing later.");
break;
}
else if (CodeCheck(dbl[i]))
{
CSharpCCErrors.Warning(exp,
"CSHARPCODE non-terminal will force this choice to be taken " +
"in favor of the choices appearing later.");
break;
}
}
}
overlapDetected = false;
for (int i = first; i < choice.Choices.Count - 1; i++)
{
for (int j = i + 1; j < choice.Choices.Count; j++)
{
if ((m = overlap(dbl[i], dbr[j])) != null)
{
minLA[i] = la + 1;
overlapInfo[i] = m;
other[i] = j;
overlapDetected = true;
break;
}
}
}
if (!overlapDetected)
{
break;
}
}
for (int i = first; i < choice.Choices.Count - 1; i++)
{
if (explicitLA((Expansion)choice.Choices[i]) && !Options.getForceLaCheck())
{
continue;
}
if (minLA[i] > Options.getChoiceAmbiguityCheck())
{
CSharpCCErrors.Warning("Choice conflict involving two expansions at");
Console.Error.Write(" line " + ((Expansion)choice.Choices[i]).Line);
Console.Error.Write(", column " + ((Expansion)choice.Choices[i]).Column);
Console.Error.Write(" and line " + ((Expansion)choice.Choices[other[i]]).Line);
Console.Error.Write(", column " + ((Expansion)choice.Choices[other[i]]).Column);
Console.Error.WriteLine(" respectively.");
Console.Error.WriteLine(" A common prefix is: " + image(overlapInfo[i]));
Console.Error.WriteLine(" Consider using a lookahead of " + minLA[i] + " or more for earlier expansion.");
}
else if (minLA[i] > 1)
{
CSharpCCErrors.Warning("Choice conflict involving two expansions at");
Console.Error.Write(" line " + ((Expansion)choice.Choices[i]).Line);
Console.Error.Write(", column " + ((Expansion)choice.Choices[i]).Column);
Console.Error.Write(" and line " + ((Expansion)choice.Choices[other[i]]).Line);
Console.Error.Write(", column " + ((Expansion)choice.Choices[other[i]]).Column);
Console.Error.WriteLine(" respectively.");
Console.Error.WriteLine(" A common prefix is: " + image(overlapInfo[i]));
Console.Error.WriteLine(" Consider using a lookahead of " + minLA[i] + " for earlier expansion.");
}
}
}
public static IList<MatchInfo> genFirstSet(IList<MatchInfo> partialMatches, Expansion exp)
{
if (exp is RegularExpression) {
IList<MatchInfo> retval = new List<MatchInfo>();
for (int i = 0; i < partialMatches.Count; i++) {
MatchInfo m = (MatchInfo) partialMatches[i];
MatchInfo mnew = new MatchInfo();
for (int j = 0; j < m.firstFreeLoc; j++) {
mnew.match[j] = m.match[j];
}
mnew.firstFreeLoc = m.firstFreeLoc;
mnew.match[mnew.firstFreeLoc++] = ((RegularExpression) exp).Ordinal;
if (mnew.firstFreeLoc == MatchInfo.laLimit) {
sizeLimitedMatches.Add(mnew);
} else {
retval.Add(mnew);
}
}
return retval;
} else if (exp is NonTerminal) {
NormalProduction prod = ((NonTerminal) exp).Production;
if (prod is CodeProduction) {
return new List<MatchInfo>();
} else {
return genFirstSet(partialMatches, prod.Expansion);
}
} else if (exp is Choice) {
IList<MatchInfo> retval = new List<MatchInfo>();
Choice ch = (Choice) exp;
foreach (Expansion e in ch.Choices) {
IList<MatchInfo> v = genFirstSet(partialMatches, e);
listAppend(retval, v);
}
return retval;
} else if (exp is Sequence) {
IList<MatchInfo> v = partialMatches;
Sequence seq = (Sequence) exp;
foreach (Expansion unit in seq.Units) {
v = genFirstSet(v, unit);
if (v.Count == 0)
break;
}
return v;
} else if (exp is OneOrMore) {
IList<MatchInfo> retval = new List<MatchInfo>();
IList<MatchInfo> v = partialMatches;
OneOrMore om = (OneOrMore) exp;
while (true) {
v = genFirstSet(v, om.Expansion);
if (v.Count == 0)
break;
listAppend(retval, v);
}
return retval;
} else if (exp is ZeroOrMore) {
IList<MatchInfo> retval = new List<MatchInfo>();
listAppend(retval, partialMatches);
IList<MatchInfo> v = partialMatches;
ZeroOrMore zm = (ZeroOrMore) exp;
while (true) {
v = genFirstSet(v, zm.Expansion);
if (v.Count == 0)
break;
listAppend(retval, v);
}
return retval;
} else if (exp is ZeroOrOne) {
IList<MatchInfo> retval = new List<MatchInfo>();
listAppend(retval, partialMatches);
listAppend(retval, genFirstSet(partialMatches, ((ZeroOrOne) exp).Expansion));
return retval;
} else if (exp is TryBlock) {
return genFirstSet(partialMatches, ((TryBlock) exp).Expansion);
} else if (considerSemanticLA &&
exp is Lookahead &&
((Lookahead) exp).ActionTokens.Count != 0
) {
return new List<MatchInfo>();
} else {
IList<MatchInfo> retval = new List<MatchInfo>();
listAppend(retval, partialMatches);
return retval;
}
}