Merge pull request #25588 from slavapestov/remove-parser-implicit-accessors

Stop synthesizing accessors inside the parser

Author: slavapestov

lib/AST/Decl.cpp

@@ -1907,6 +1907,16 @@ bool AbstractStorageDecl::requiresOpaqueModifyCoroutine() const {
   if (!supportsMutation())
     return false;
 
+  auto *dc = getDeclContext();
+
+  // Local properties don't have modify accessors.
+  if (dc->isLocalContext())
+    return false;
+
+  // Fixed-layout global properties don't have modify accessors.
+  if (dc->isModuleScopeContext() && !isResilient())
+    return false;
+
   // Imported storage declarations don't have eagerly-generated modify
   // accessors.
   if (hasClangNode())
@@ -1919,7 +1929,6 @@ bool AbstractStorageDecl::requiresOpaqueModifyCoroutine() const {
     return false;
 
   // Requirements of ObjC protocols don't support the modify coroutine.
-  auto *dc = getDeclContext();
   if (auto protoDecl = dyn_cast<ProtocolDecl>(dc))
     if (protoDecl->isObjC())
       return false;

lib/Parse/ParseDecl.cpp

@@ -4969,32 +4969,6 @@ Parser::ParsedAccessors::classify(Parser &P, AbstractStorageDecl *storage,
   if (auto *subscript = dyn_cast<SubscriptDecl>(storage))
     genericParams = subscript->getGenericParams();
 
-  // Create an implicit accessor declaration.
-  auto createImplicitAccessor = [&](AccessorKind kind,
-                                    AccessorDecl *funcForParams = nullptr) {
-    // We never use this to create addressors.
-    assert(kind != AccessorKind::Address &&
-           kind != AccessorKind::MutableAddress);
-
-    // Create the paramter list for a setter.
-    ParameterList *argList = nullptr;
-    if (kind == AccessorKind::Set) {
-      assert(funcForParams);
-      auto argLoc = funcForParams->getStartLoc();
-
-      auto argument = createSetterAccessorArgument(
-          argLoc, Identifier(), AccessorKind::Set, P, elementTy);
-      argList = ParameterList::create(P.Context, argument);
-    }
-
-    auto accessor = createAccessorFunc(SourceLoc(), argList,
-                                       genericParams, indices, elementTy,
-                                       staticLoc, flags, kind,
-                                       storage, &P, SourceLoc());
-    accessor->setImplicit();
-    add(accessor);
-  };
-
   // If there was a problem parsing accessors, mark all parsed accessors
   // as invalid to avoid tripping up later invariants.
   // We also want to avoid diagnose missing accessors if something
@@ -5021,12 +4995,6 @@ Parser::ParsedAccessors::classify(Parser &P, AbstractStorageDecl *storage,
 
     // Otherwise, we have either a stored or inherited observing property.
     } else {
-      // Observing properties will have getters and setters synthesized
-      // by Sema.  Create their prototypes now.
-      auto argFunc = (WillSet ? WillSet : DidSet);
-      createImplicitAccessor(AccessorKind::Get);
-      createImplicitAccessor(AccessorKind::Set, argFunc);
-
       if (attrs.hasAttribute<OverrideAttr>()) {
         return StorageImplInfo(ReadImplKind::Inherited,
                                WriteImplKind::InheritedWithObservers,
@@ -5067,7 +5035,7 @@ Parser::ParsedAccessors::classify(Parser &P, AbstractStorageDecl *storage,
                  isa<SubscriptDecl>(storage),
                  getAccessorNameForDiagnostic(mutator, /*article*/ true));
     }
-    createImplicitAccessor(AccessorKind::Get);
+
     readImpl = ReadImplKind::Get;
 
   // Subscripts always have to have some sort of accessor; they can't be
@@ -5077,7 +5045,6 @@ Parser::ParsedAccessors::classify(Parser &P, AbstractStorageDecl *storage,
       P.diagnose(LBLoc, diag::subscript_without_get);
     }
 
-    createImplicitAccessor(AccessorKind::Get);
     readImpl = ReadImplKind::Get;
 
   // Otherwise, it's stored.

lib/SILGen/SILGen.cpp

@@ -1316,48 +1316,17 @@ void SILGenModule::visitVarDecl(VarDecl *vd) {
   if (vd->hasStorage())
     addGlobalVariable(vd);
 
-  // Emit the variable's opaque accessors.
-  vd->visitExpectedOpaqueAccessors([&](AccessorKind kind) {
-    auto accessor = vd->getAccessor(kind);
-    if (!accessor) return;
-
-    // Only emit the accessor if it wasn't added to the surrounding decl
-    // list by the parser.  We can test that easily by looking at the impl
-    // info, since all of these accessors have a corresponding access kind
-    // whose impl should definitely point at the accessor if it was parsed.
-    //
-    // This is an unfortunate formation rule, but it's easier than messing
-    // with the invariants for now.
-    bool shouldEmit = [&] {
-      auto impl = vd->getImplInfo();
-      switch (kind) {
-      case AccessorKind::Get:
-        return impl.getReadImpl() != ReadImplKind::Get &&
-               !(impl.getReadImpl() == ReadImplKind::Stored &&
-                 impl.getWriteImpl() == WriteImplKind::StoredWithObservers);
-      case AccessorKind::Read:
-        return impl.getReadImpl() != ReadImplKind::Read;
-      case AccessorKind::Set:
-        return impl.getWriteImpl() != WriteImplKind::Set &&
-               impl.getWriteImpl() != WriteImplKind::StoredWithObservers;
-      case AccessorKind::Modify:
-        return impl.getReadWriteImpl() != ReadWriteImplKind::Modify;
-#define ACCESSOR(ID) \
-      case AccessorKind::ID:
-#define OPAQUE_ACCESSOR(ID, KEYWORD)
-#include "swift/AST/AccessorKinds.def"
-        llvm_unreachable("not an opaque accessor");
-      }
-      llvm_unreachable("covered switch");
-    }();
-    if (!shouldEmit) return;
-
+  for (auto *accessor : vd->getAllAccessors())
     emitFunction(accessor);
-  });
 
   tryEmitPropertyDescriptor(vd);
 }
 
+void SILGenModule::visitSubscriptDecl(SubscriptDecl *sd) {
+  for (auto *accessor : sd->getAllAccessors())
+    emitFunction(accessor);
+}
+
 bool
 SILGenModule::canStorageUseStoredKeyPathComponent(AbstractStorageDecl *decl,
                                                   ResilienceExpansion expansion) {

lib/SILGen/SILGen.h

@@ -188,12 +188,14 @@ class LLVM_LIBRARY_VISIBILITY SILGenModule : public ASTVisitor<SILGenModule> {
   void visitTypeAliasDecl(TypeAliasDecl *d) {}
   void visitOpaqueTypeDecl(OpaqueTypeDecl *d) {}
   void visitAbstractTypeParamDecl(AbstractTypeParamDecl *d) {}
-  void visitSubscriptDecl(SubscriptDecl *d) {}
   void visitConstructorDecl(ConstructorDecl *d) {}
   void visitDestructorDecl(DestructorDecl *d) {}
   void visitModuleDecl(ModuleDecl *d) { }
   void visitMissingMemberDecl(MissingMemberDecl *d) {}
 
+  // Emitted as part of its storage.
+  void visitAccessorDecl(AccessorDecl *ad) {}
+
   void visitFuncDecl(FuncDecl *fd);
   void visitPatternBindingDecl(PatternBindingDecl *vd);
   void visitTopLevelCodeDecl(TopLevelCodeDecl *td);
@@ -202,6 +204,7 @@ class LLVM_LIBRARY_VISIBILITY SILGenModule : public ASTVisitor<SILGenModule> {
   void visitNominalTypeDecl(NominalTypeDecl *ntd);
   void visitExtensionDecl(ExtensionDecl *ed);
   void visitVarDecl(VarDecl *vd);
+  void visitSubscriptDecl(SubscriptDecl *sd);
 
   void emitAbstractFuncDecl(AbstractFunctionDecl *AFD);
 

lib/SILGen/SILGenDecl.cpp

@@ -1192,6 +1192,10 @@ void SILGenFunction::visitPatternBindingDecl(PatternBindingDecl *PBD) {
 
 void SILGenFunction::visitVarDecl(VarDecl *D) {
   // We handle emitting the variable storage when we see the pattern binding.
+
+  // Emit the variable's accessors.
+  for (auto *accessor : D->getAllAccessors())
+    SGM.emitFunction(accessor);
 }
 
 /// Emit literals for the major, minor, and subminor components of the version

lib/SILGen/SILGenFunction.h

@@ -1787,6 +1787,9 @@ class LLVM_LIBRARY_VISIBILITY SILGenFunction
     llvm_unreachable("Not yet implemented");
   }
 
+  // Emitted as part of its storage.
+  void visitAccessorDecl(AccessorDecl *D) {}
+
   void visitFuncDecl(FuncDecl *D);
   void visitPatternBindingDecl(PatternBindingDecl *D);
 

lib/Sema/CodeSynthesis.cpp

@@ -72,7 +72,7 @@ static void addMemberToContextIfNeeded(Decl *D, DeclContext *DC,
   } else if (auto *ed = dyn_cast<ExtensionDecl>(DC)) {
     ed->addMember(D, Hint);
   } else {
-    assert((isa<AbstractFunctionDecl>(DC) || isa<FileUnit>(DC)) &&
+    assert((DC->isLocalContext() || isa<FileUnit>(DC)) &&
            "Unknown declcontext");
   }
 }
@@ -2036,8 +2036,8 @@ void swift::maybeAddAccessorsToStorage(AbstractStorageDecl *storage) {
 
   auto *dc = storage->getDeclContext();
 
-  // Local variables don't otherwise get accessors.
-  if (dc->isLocalContext())
+  // Local stored variables don't otherwise get accessors.
+  if (dc->isLocalContext() && storage->getImplInfo().isSimpleStored())
     return;
 
   // Implicit properties don't get accessors.
@@ -2053,7 +2053,7 @@ void swift::maybeAddAccessorsToStorage(AbstractStorageDecl *storage) {
       return;
     }
     // Fixed-layout global variables don't get accessors.
-    if (!storage->isResilient())
+    if (!storage->isResilient() && storage->getImplInfo().isSimpleStored())
       return;
 
   // In a protocol context, variables written as just "var x : Int" or