AST: Remove TypeBase::gatherAllSubstitutions()

lib/AST/Module.cpp

@@ -555,106 +555,6 @@ void ModuleDecl::getDisplayDecls(SmallVectorImpl<Decl*> &Results) const {
   FORWARD(getDisplayDecls, (Results));
 }
 
-SubstitutionList
-TypeBase::gatherAllSubstitutions(ModuleDecl *module,
-                                 LazyResolver *resolver,
-                                 DeclContext *gpContext) {
-  // FIXME: If there is no module, infer one. This is a hack for callers that
-  // don't have access to the module. It will have to go away once we're
-  // properly differentiating bound generic types based on the protocol
-  // conformances visible from a given module.
-  if (!module)
-    module = getAnyNominal()->getParentModule();
-
-  // Check the context, introducing the default if needed.
-  if (!gpContext)
-    gpContext = getAnyNominal();
-
-  assert(gpContext->getAsNominalTypeOrNominalTypeExtensionContext()
-         == getAnyNominal() && "not a valid context");
-
-  auto *genericSig = gpContext->getGenericSignatureOfContext();
-  if (genericSig == nullptr)
-    return { };
-
-  // If we already have a cached copy of the substitutions, return them.
-  const ASTContext &ctx = getASTContext();
-  if (auto known = ctx.getSubstitutions(this, gpContext))
-    return *known;
-
-  // Compute the set of substitutions.
-  TypeSubstitutionMap substitutions;
-
-  // The type itself contains substitutions up to the innermost
-  // non-type context.
-  Type parent = this;
-  ArrayRef<GenericTypeParamType *> genericParams =
-    genericSig->getGenericParams();
-  unsigned lastGenericIndex = genericParams.size();
-  while (parent) {
-    if (auto boundGeneric = parent->getAs<BoundGenericType>()) {
-      unsigned index = lastGenericIndex - boundGeneric->getGenericArgs().size();
-      for (Type arg : boundGeneric->getGenericArgs()) {
-        auto paramTy = genericParams[index++];
-        substitutions[
-          paramTy->getCanonicalType()->castTo<GenericTypeParamType>()] = arg;
-      }
-      lastGenericIndex -= boundGeneric->getGenericArgs().size();
-
-      parent = boundGeneric->getParent();
-      continue;
-    }
-
-    if (auto protocol = parent->getAs<ProtocolType>()) {
-      parent = protocol->getParent();
-      lastGenericIndex--;
-      continue;
-    }
-
-    if (auto nominal = parent->getAs<NominalType>()) {
-      parent = nominal->getParent();
-      continue;
-    }
-
-    llvm_unreachable("Not a nominal or bound generic type");
-  }
-
-  auto *genericEnv = gpContext->getGenericEnvironmentOfContext();
-
-  // Add forwarding substitutions from the outer context if we have
-  // a type nested inside a generic function.
-  auto *parentDC = gpContext;
-  while (parentDC->isTypeContext())
-    parentDC = parentDC->getParent();
-  if (auto *outerSig = parentDC->getGenericSignatureOfContext()) {
-    for (auto gp : outerSig->getGenericParams()) {
-      auto result = substitutions.insert(
-                      {gp->getCanonicalType()->castTo<GenericTypeParamType>(),
-                       genericEnv->mapTypeIntoContext(gp)});
-      assert(result.second);
-      (void) result;
-    }
-  }
-
-  SmallVector<Substitution, 4> result;
-  genericSig->getSubstitutions(substitutions,
-                               LookUpConformanceInModule(module),
-                               result);
-
-  // Before recording substitutions, make sure we didn't end up doing it
-  // recursively.
-  if (auto known = ctx.getSubstitutions(this, gpContext))
-    return *known;
-
-  // Copy and record the substitutions.
-  auto permanentSubs = ctx.AllocateCopy(result,
-                                        hasTypeVariable()
-                                          ? AllocationArena::ConstraintSolver
-                                          : AllocationArena::Permanent);
-  ctx.setSubstitutions(this, gpContext, permanentSubs);
-  return permanentSubs;
-}
-
 Optional<ProtocolConformanceRef>
 ModuleDecl::lookupConformance(Type type, ProtocolDecl *protocol,
                               LazyResolver *resolver) {