/// <summary> Determine which of two signatures is the closer fit.
/// Returns one of PREFERENCE_EQUAL, PREFERENCE_FIRST_ARG,
/// PREFERENCE_SECOND_ARG, or PREFERENCE_AMBIGUOUS.
/// </summary>
private static int PreferSignature(object [] args, ParameterInfo [] sig1, ParameterInfo [] sig2)
{
int totalPreference = 0;
for (int j = 0; j < args.Length; j++)
{
Type type1 = sig1 [j].ParameterType;
Type type2 = sig2 [j].ParameterType;
if (type1 == type2)
{
continue;
}
object arg = args [j];
// Determine which of type1, type2 is easier to convert from arg.
int rank1 = CliObject.GetConversionWeight(arg, type1);
int rank2 = CliObject.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 == CliObject.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);
}
private void Init()
{
m_CliObject = new CliObject(m_Type, m_Type);
}
/// <summary> 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.
/// </summary>
internal static int FindFunction(Context cx, MethodBase [] methodsOrCtors, object [] args, bool [] paramsParameter)
{
if (methodsOrCtors.Length == 0)
{
return(-1);
}
else if (methodsOrCtors.Length == 1)
{
MethodBase member = methodsOrCtors [0];
ParameterInfo [] pis = member.GetParameters();
int alength = pis.Length;
if (alength != args.Length)
{
if (!paramsParameter [0])
{
return(-1);
}
}
for (int j = 0; j != alength; ++j)
{
object arg = args [j];
Type argType = null;
if (paramsParameter [0] && j >= pis.Length - 1)
{
// params[] arg is always an array type
argType = pis [pis.Length - 1].ParameterType.GetElementType();
}
else
{
argType = pis [j].ParameterType;
}
if (!CliObject.CanConvert(arg, argType))
{
//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;
for (int i = 0; i < methodsOrCtors.Length; i++)
{
MethodBase member = methodsOrCtors [i];
ParameterInfo [] pis = member.GetParameters();
if (pis.Length != args.Length)
{
goto search;
}
for (int j = 0; j < pis.Length; j++)
{
if (!CliObject.CanConvert(args [j], pis [j].ParameterType))
{
//if (debug)
// printDebug("Rejecting (args can't convert) ", member, args);
goto 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];
}
MethodBase bestFit = methodsOrCtors [bestFitIndex];
int preference = PreferSignature(args, pis, bestFit.GetParameters());
if (preference == PREFERENCE_AMBIGUOUS)
{
break;
}
else if (preference == PREFERENCE_FIRST_ARG)
{
++betterCount;
}
else if (preference == PREFERENCE_SECOND_ARG)
{
++worseCount;
}
else
{
if (preference != PREFERENCE_EQUAL)
{
Context.CodeBug();
}
// This should not happen in theory
// but on some JVMs, Class.getMethods will return all
// static methods of the class heirarchy, even if
// a derived class's parameters match exactly.
// We want to call the dervied class's method.
if (bestFit.IsStatic && bestFit.DeclaringType.IsAssignableFrom(member.DeclaringType))
{
// On some JVMs, Class.getMethods will return all
// static methods of the class heirarchy, even if
// a derived class's parameters match exactly.
// We want to call the dervied 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);
}
goto 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;
}
}
//UPGRADE_NOTE: Label 'search' was moved. 'ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="jlca1014_3"'
search:
;
}
if (firstBestFit < 0)
{
// Nothing was found
return(-1);
}
else if (extraBestFitsCount == 0)
{
// single best fit
return(firstBestFit);
}
// report remaining ambiguity
System.Text.StringBuilder buf = new System.Text.StringBuilder();
for (int j = -1; j != extraBestFitsCount; ++j)
{
int bestFitIndex;
if (j == -1)
{
bestFitIndex = firstBestFit;
}
else
{
bestFitIndex = extraBestFits [j];
}
buf.Append("\n ");
buf.Append(CliHelper.ToSignature(methodsOrCtors [bestFitIndex]));
}
MethodBase firstFitMember = methodsOrCtors [firstBestFit];
string memberName = firstFitMember.Name;
//UPGRADE_TODO: The equivalent in .NET for method 'java.lang.Class.getName' may return a different value. 'ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="jlca1043_3"'
string memberClass = firstFitMember.DeclaringType.FullName;
if (methodsOrCtors [0] is MethodInfo)
{
throw Context.ReportRuntimeErrorById("msg.constructor.ambiguous", memberName, ScriptSignature(args), buf.ToString());
}
else
{
throw Context.ReportRuntimeErrorById("msg.method.ambiguous", memberClass, memberName, ScriptSignature(args), buf.ToString());
}
}
private void Init()
{
m_CliObject = new CliObject (m_Type, m_Type);
}
