[NFC] Remove Existential Ranking Hack
This hack was originally intended to distinguish between functions
of single arguments that were overloaded on AnyObject and AnyObject?.
Nowadays, CSRanking is capable of handling that itself, and the check
this function was using to detect AnyObject no longer works.
diff --git a/lib/Sema/CSRanking.cpp b/lib/Sema/CSRanking.cpp
index 71f9f57..f37e0bc 100644
--- a/lib/Sema/CSRanking.cpp
+++ b/lib/Sema/CSRanking.cpp
@@ -309,56 +309,6 @@
return false;
}
-static Type getTypeAtIndex(const ParameterList *params, size_t index) {
- if (params->size() == 0)
- return nullptr;
-
- if (index < params->size()) {
- auto param = params->get(index);
- if (param->isVariadic())
- return param->getVarargBaseTy();
-
- return param->getInterfaceType();
- }
-
- /// FIXME: This looks completely wrong for varargs within a parameter list.
- if (params->size() != 0) {
- auto lastParam = params->getArray().back();
- if (lastParam->isVariadic())
- return lastParam->getVarargBaseTy();
- }
-
- return nullptr;
-}
-
-/// For two function declarations, determine if a parameter of the second is an
-/// empty existential composition ("Any"), and if it would otherwise be compared
-/// against a non-existential parameter at the same position of the first decl.
-/// This is used to disambiguate function overloads that would otherwise be
-/// identical after opening their parameter types.
-static bool hasEmptyExistentialParameterMismatch(ValueDecl *decl1,
- ValueDecl *decl2) {
- auto func1 = dyn_cast<FuncDecl>(decl1);
- auto func2 = dyn_cast<FuncDecl>(decl2);
- if (!func1 || !func2) return false;
-
- auto pl1 = func1->getParameterLists();
- auto pl2 = func2->getParameterLists();
-
- auto pc = std::min(pl1.size(), pl2.size());
-
- for (size_t i = 0; i < pc; i++) {
- auto t1 = getTypeAtIndex(pl1[i], i);
- auto t2 = getTypeAtIndex(pl2[i], i);
- if (!t1 || !t2)
- return false;
-
- if (t2->isAnyExistentialType() && !t1->isAnyExistentialType())
- return t2->isAny();
- }
- return false;
-}
-
/// Determine whether one protocol extension is at least as specialized as
/// another.
static bool isProtocolExtensionAsSpecializedAs(TypeChecker &tc,
@@ -948,19 +898,6 @@
foundRefinement2 = true;
}
}
-
- // If we still haven't found a refinement, check if there's a parameter-
- // wise comparison between an empty existential collection and a non-
- // existential type.
- if (!(foundRefinement1 && foundRefinement2)) {
- if (hasEmptyExistentialParameterMismatch(decl1, decl2)) {
- foundRefinement1 = true;
- }
-
- if (hasEmptyExistentialParameterMismatch(decl2, decl1)) {
- foundRefinement2 = true;
- }
- }
// FIXME: The rest of the hack for restating requirements.
if (!(foundRefinement1 && foundRefinement2)) {
