public override Expression VisitMethodCall(MethodCall call) {
if (call == null) return null;
MemberBinding mb = call.Callee as MemberBinding;
Method m = mb == null ? null : mb.BoundMember as Method;
if (m != null && !this.typeSystem.insideUnsafeCode) {
bool badMethod = m.ReturnType is Pointer;
for (int i = 0, n = m.Parameters == null ? 0 : m.Parameters.Count; i < n; i++) {
Parameter p = m.Parameters[i];
if (p == null) continue;
if (p.Type is Pointer) { badMethod = true; break; }
}
if (badMethod && call.SourceContext.Document != null) {
this.HandleError(call, Error.UnsafeNeeded);
return null;
}
}
#region Pure methods that have an out parameter cannot be used in a contract
// This is checked here and not where ref parameters are checked (VisitMethod)
// because we want to allow pure methods to have out parameters for use in purity
// analysis. It is just that Boogie doesn't generate the right axioms, etc. for
// pure methods that have out parameters. So for now, just don't allow them in
// contracts.
if ((insideMethodContract || insideInvariant || insideAssertOrAssume)
&& m != null && !m.IsPropertyGetter
&& (m.IsPure || m.IsConfined || m.IsStateIndependent)) {
// don't check property getters: they already will have an error if they have out parameters.
for (int i = 0, n = m.Parameters == null ? 0 : m.Parameters.Count; i < n; i++) {
Parameter p = m.Parameters[i];
if (p.IsOut) {
this.HandleError(p, Error.PureMethodWithOutParamUsedInContract);
}
}
}
#endregion
// if any two arguments Might Return Newly Allocated Object then method must be marked NoReferenceComparison
if ((insideMethodContract || insideInvariant || insideAssertOrAssume) && m != null && mb != null) {
int MRNAOargs = 0;
MightReturnNewlyAllocatedObjectVisitor visitor = new MightReturnNewlyAllocatedObjectVisitor(this);
this.TransferStateTo(visitor);
visitor.CurrentMethod = this.currentMethod;
// receiver
visitor.Visit(mb);
if (visitor.IsMRNAO)
MRNAOargs++;
else // parameters
for (int i = 0, n = call.Operands == null ? 0 : call.Operands.Count; i < n; i++) {
Expression exp = call.Operands[i];
visitor.IsMRNAO = false;
visitor.Visit(exp);
if (visitor.IsMRNAO) {
MRNAOargs++;
}
}
if (MRNAOargs > 1 && m.GetAttribute(SystemTypes.NoReferenceComparisonAttribute) == null) {
this.HandleError(call, Error.MethodShouldBeMarkedNoReferenceComparison, m.Name.ToString());
return null;
}
}
return base.VisitMethodCall(call);
}