[embedded] Move default arg logic from postEmitFunction to SILDeclRef::isTransparent

Author: kubamracek

lib/SIL/IR/SILDeclRef.cpp

@@ -820,6 +820,20 @@ bool SILDeclRef::isTransparent() const {
     }
   }
 
+  // To support using metatypes as type hints in Embedded Swift. A default
+  // argument generator might be returning a metatype, which we normally don't
+  // support in Embedded Swift, but to still allow metatypes as type hints, we
+  // make the generator always inline to the callee by marking it transparent.
+  if (getASTContext().LangOpts.hasFeature(Feature::Embedded)) {
+    if (isDefaultArgGenerator() && hasDecl()) {
+      auto *decl = getDecl();
+      auto *param = getParameterAt(decl, defaultArgIndex);
+      Type paramType = param->getTypeOfDefaultExpr();
+      if (paramType && paramType->is<MetatypeType>())
+        return true;
+    }
+  }
+
   if (hasDecl()) {
     if (auto *AFD = dyn_cast<AbstractFunctionDecl>(getDecl()))
       return AFD->isTransparent();

lib/SILGen/SILGen.cpp

@@ -1280,28 +1280,6 @@ void SILGenModule::postEmitFunction(SILDeclRef constant,
   F->verifyIncompleteOSSA();
 
   emitDifferentiabilityWitnessesForFunction(constant, F);
-
-  // To support using metatypes as type hints in Embedded Swift. A default
-  // argument generator might be returning a metatype, which we normally don't
-  // support in Embedded Swift, but to still allow metatypes as type hints, we
-  // make the generator always inline to the callee by marking it transparent.
-  if (M.getOptions().EmbeddedSwift) {
-    if (constant.isDefaultArgGenerator()) {
-      bool isReturningMetatype = false;
-      if (F->getLoweredFunctionType()->getNumResults() == 1) {
-        if (F->getLoweredFunctionType()
-                ->getSingleResult()
-                .getSILStorageInterfaceType()
-                .isMetatype()) {
-          isReturningMetatype = true;
-        }
-      }
-
-      if (isReturningMetatype) {
-        F->setTransparent(IsTransparent);
-      }
-    }
-  }
 }
 
 void SILGenModule::emitDifferentiabilityWitnessesForFunction(