/**
* Determine which of two signatures is the closer fit. Returns one of PREFERENCE_EQUAL,
* PREFERENCE_FIRST_ARG, PREFERENCE_SECOND_ARG, or PREFERENCE_AMBIGUOUS.
*/
private static int preferSignature(
Object[] args, Class<?>[] sig1, boolean vararg1, Class<?>[] sig2, boolean vararg2) {
int totalPreference = 0;
for (int j = 0; j < args.length; j++) {
Class<?> type1 = vararg1 && j >= sig1.length ? sig1[sig1.length - 1] : sig1[j];
Class<?> type2 = vararg2 && j >= sig2.length ? sig2[sig2.length - 1] : sig2[j];
if (type1 == type2) {
continue;
}
Object arg = args[j];
// Determine which of type1, type2 is easier to convert from arg.
int rank1 = NativeJavaObject.getConversionWeight(arg, type1);
int rank2 = NativeJavaObject.getConversionWeight(arg, type2);
int preference;
if (rank1 < rank2) {
preference = PREFERENCE_FIRST_ARG;
} else if (rank1 > rank2) {
preference = PREFERENCE_SECOND_ARG;
} else {
// Equal ranks
if (rank1 == NativeJavaObject.CONVERSION_NONTRIVIAL) {
if (type1.isAssignableFrom(type2)) {
preference = PREFERENCE_SECOND_ARG;
} else if (type2.isAssignableFrom(type1)) {
preference = PREFERENCE_FIRST_ARG;
} else {
preference = PREFERENCE_AMBIGUOUS;
}
} else {
preference = PREFERENCE_AMBIGUOUS;
}
}
totalPreference |= preference;
if (totalPreference == PREFERENCE_AMBIGUOUS) {
break;
}
}
return totalPreference;
}
/**
* Find the index of the correct function to call given the set of methods or constructors and the
* arguments. If no function can be found to call, return -1.
*/
static int findFunction(Context cx, MemberBox[] methodsOrCtors, Object[] args) {
if (methodsOrCtors.length == 0) {
return -1;
} else if (methodsOrCtors.length == 1) {
MemberBox member = methodsOrCtors[0];
Class<?>[] argTypes = member.argTypes;
int alength = argTypes.length;
if (member.vararg) {
alength--;
if (alength > args.length) {
return -1;
}
} else {
if (alength != args.length) {
return -1;
}
}
for (int j = 0; j != alength; ++j) {
if (!NativeJavaObject.canConvert(args[j], argTypes[j])) {
if (debug) printDebug("Rejecting (args can't convert) ", member, args);
return -1;
}
}
if (debug) printDebug("Found ", member, args);
return 0;
}
int firstBestFit = -1;
int[] extraBestFits = null;
int extraBestFitsCount = 0;
search:
for (int i = 0; i < methodsOrCtors.length; i++) {
MemberBox member = methodsOrCtors[i];
Class<?>[] argTypes = member.argTypes;
int alength = argTypes.length;
if (member.vararg) {
alength--;
if (alength > args.length) {
continue search;
}
} else {
if (alength != args.length) {
continue search;
}
}
for (int j = 0; j < alength; j++) {
if (!NativeJavaObject.canConvert(args[j], argTypes[j])) {
if (debug) printDebug("Rejecting (args can't convert) ", member, args);
continue search;
}
}
if (firstBestFit < 0) {
if (debug) printDebug("Found first applicable ", member, args);
firstBestFit = i;
} else {
// Compare with all currently fit methods.
// The loop starts from -1 denoting firstBestFit and proceed
// until extraBestFitsCount to avoid extraBestFits allocation
// in the most common case of no ambiguity
int betterCount = 0; // number of times member was prefered over
// best fits
int worseCount = 0; // number of times best fits were prefered
// over member
for (int j = -1; j != extraBestFitsCount; ++j) {
int bestFitIndex;
if (j == -1) {
bestFitIndex = firstBestFit;
} else {
bestFitIndex = extraBestFits[j];
}
MemberBox bestFit = methodsOrCtors[bestFitIndex];
if (cx.hasFeature(Context.FEATURE_ENHANCED_JAVA_ACCESS)
&& (bestFit.member().getModifiers() & Modifier.PUBLIC)
!= (member.member().getModifiers() & Modifier.PUBLIC)) {
// When FEATURE_ENHANCED_JAVA_ACCESS gives us access
// to non-public members, continue to prefer public
// methods in overloading
if ((bestFit.member().getModifiers() & Modifier.PUBLIC) == 0) ++betterCount;
else ++worseCount;
} else {
int preference =
preferSignature(args, argTypes, member.vararg, bestFit.argTypes, bestFit.vararg);
if (preference == PREFERENCE_AMBIGUOUS) {
break;
} else if (preference == PREFERENCE_FIRST_ARG) {
++betterCount;
} else if (preference == PREFERENCE_SECOND_ARG) {
++worseCount;
} else {
if (preference != PREFERENCE_EQUAL) Kit.codeBug();
// This should not happen in theory
// but on some JVMs, Class.getMethods will return all
// static methods of the class hierarchy, even if
// a derived class's parameters match exactly.
// We want to call the derived class's method.
if (bestFit.isStatic()
&& bestFit.getDeclaringClass().isAssignableFrom(member.getDeclaringClass())) {
// On some JVMs, Class.getMethods will return all
// static methods of the class hierarchy, even if
// a derived class's parameters match exactly.
// We want to call the derived class's method.
if (debug) printDebug("Substituting (overridden static)", member, args);
if (j == -1) {
firstBestFit = i;
} else {
extraBestFits[j] = i;
}
} else {
if (debug) printDebug("Ignoring same signature member ", member, args);
}
continue search;
}
}
}
if (betterCount == 1 + extraBestFitsCount) {
// member was prefered over all best fits
if (debug) printDebug("New first applicable ", member, args);
firstBestFit = i;
extraBestFitsCount = 0;
} else if (worseCount == 1 + extraBestFitsCount) {
// all best fits were prefered over member, ignore it
if (debug) printDebug("Rejecting (all current bests better) ", member, args);
} else {
// some ambiguity was present, add member to best fit set
if (debug) printDebug("Added to best fit set ", member, args);
if (extraBestFits == null) {
// Allocate maximum possible array
extraBestFits = new int[methodsOrCtors.length - 1];
}
extraBestFits[extraBestFitsCount] = i;
++extraBestFitsCount;
}
}
}
if (firstBestFit < 0) {
// Nothing was found
return -1;
} else if (extraBestFitsCount == 0) {
// single best fit
return firstBestFit;
}
// report remaining ambiguity
StringBuffer buf = new StringBuffer();
for (int j = -1; j != extraBestFitsCount; ++j) {
int bestFitIndex;
if (j == -1) {
bestFitIndex = firstBestFit;
} else {
bestFitIndex = extraBestFits[j];
}
buf.append("\n ");
buf.append(methodsOrCtors[bestFitIndex].toJavaDeclaration());
}
MemberBox firstFitMember = methodsOrCtors[firstBestFit];
String memberName = firstFitMember.getName();
String memberClass = firstFitMember.getDeclaringClass().getName();
if (methodsOrCtors[0].isMethod()) {
throw Context.reportRuntimeError3(
"msg.constructor.ambiguous", memberName, scriptSignature(args), buf.toString());
} else {
throw Context.reportRuntimeError4(
"msg.method.ambiguous", memberClass, memberName, scriptSignature(args), buf.toString());
}
}
public static Scriptable createAdapterWrapper(Scriptable obj, Object adapter) {
Scriptable scope = ScriptableObject.getTopLevelScope(obj);
NativeJavaObject res = new NativeJavaObject(scope, adapter, null, true);
res.setPrototype(obj);
return res;
}
