[AST] Introduce Decl::addAttribute

Introduce a convenience entrypoint that also calls `attachToDecl` on
the attribute, and migrate all existing uses of `getAttrs().add` onto
it.

Author: hamishknight

include/swift/AST/Decl.h

@@ -1039,6 +1039,13 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl>, public Swi
     return Attrs;
   }
 
+  /// Adds a given attribute to the Decl. This should be preferred over
+  /// \c getAttrs().add(...) since it also attaches the attribute if necessary.
+  void addAttribute(DeclAttribute *attr) {
+    attr->attachToDecl(this);
+    getAttrs().add(attr);
+  }
+
   /// Returns the attributes that were directly attached to this declaration
   /// as written in source, ie. does not include semantic attributes or ones
   /// generated by macro expansions.

lib/AST/ASTContext.cpp

@@ -1416,7 +1416,7 @@ ASTContext::synthesizeInvertibleProtocolDecl(InvertibleProtocolKind ip) const {
   protocol->setImplicit(true);
 
   // @_marker
-  protocol->getAttrs().add(new (*this) MarkerAttr(/*implicit=*/true));
+  protocol->addAttribute(new (*this) MarkerAttr(/*implicit=*/true));
 
   // public
   protocol->setAccess(AccessLevel::Public);

lib/AST/Availability.cpp

@@ -201,13 +201,11 @@ void AvailabilityInference::applyInferredAvailableAttrs(
     } while (D);
   }
 
-  DeclAttributes &Attrs = ToDecl->getAttrs();
-
   // Create an availability attribute for each observed platform and add
   // to ToDecl.
   for (auto &Pair : Inferred) {
     if (auto Attr = createAvailableAttr(Pair.first, Pair.second, Context))
-      Attrs.add(Attr);
+      ToDecl->addAttribute(Attr);
   }
 }
 

lib/AST/Builtins.cpp

@@ -511,7 +511,7 @@ static FuncDecl *getBuiltinGenericFunction(
   func->setAccess(AccessLevel::Public);
   func->setGenericSignature(Sig);
   if (Throws == BuiltinThrowsKind::Rethrows)
-    func->getAttrs().add(new (Context) RethrowsAttr(/*ThrowsLoc*/ SourceLoc()));
+    func->addAttribute(new (Context) RethrowsAttr(/*ThrowsLoc*/ SourceLoc()));
 
   return func;
 }
@@ -1010,7 +1010,7 @@ static ValueDecl *getBindMemoryOperation(ASTContext &ctx, Identifier id) {
                                                 _word,
                                                 _metatype(_typeparam(0))),
                                     _word);
-  fd->getAttrs().add(new (ctx) DiscardableResultAttr(/*implicit*/true));
+  fd->addAttribute(new (ctx) DiscardableResultAttr(/*implicit*/ true));
   return fd;
 }
 
@@ -1019,7 +1019,7 @@ static ValueDecl *getRebindMemoryOperation(ASTContext &ctx, Identifier id) {
                                     _parameters(_rawPointer,
                                                 _word),
                                     _word);
-  fd->getAttrs().add(new (ctx) DiscardableResultAttr(/*implicit*/true));
+  fd->addAttribute(new (ctx) DiscardableResultAttr(/*implicit*/ true));
   return fd;
 }
 

lib/AST/Decl.cpp

@@ -5579,7 +5579,7 @@ void ValueDecl::copyFormalAccessFrom(const ValueDecl *source,
                                               this)) {
     auto &ctx = getASTContext();
     auto *clonedAttr = new (ctx) UsableFromInlineAttr(/*implicit=*/true);
-    getAttrs().add(clonedAttr);
+    addAttribute(clonedAttr);
   }
 }
 
@@ -9264,7 +9264,7 @@ void ParamDecl::setNonEphemeralIfPossible() {
 
   if (!getAttrs().hasAttribute<NonEphemeralAttr>()) {
     auto &ctx = getASTContext();
-    getAttrs().add(new (ctx) NonEphemeralAttr(/*IsImplicit*/ true));
+    addAttribute(new (ctx) NonEphemeralAttr(/*IsImplicit*/ true));
   }
 }
 

lib/AST/Expr.cpp

@@ -1377,8 +1377,8 @@ CaptureListEntry CaptureListEntry::createParsed(
       new (Ctx) VarDecl(/*isStatic==*/false, introducer, nameLoc, name, DC);
 
   if (ownershipKind != ReferenceOwnership::Strong)
-    VD->getAttrs().add(
-        new (Ctx) ReferenceOwnershipAttr(ownershipRange, ownershipKind));
+    VD->addAttribute(new (Ctx)
+                         ReferenceOwnershipAttr(ownershipRange, ownershipKind));
 
   auto *pattern = NamedPattern::createImplicit(Ctx, VD);
 

lib/AST/TypeCheckRequests.cpp

@@ -331,7 +331,8 @@ void IsFinalRequest::cacheResult(bool value) const {
 
   // Add an attribute for printing
   if (value && !decl->getAttrs().hasAttribute<FinalAttr>())
-    decl->getAttrs().add(new (decl->getASTContext()) FinalAttr(/*Implicit=*/true));
+    decl->addAttribute(new (decl->getASTContext())
+                           FinalAttr(/*Implicit=*/true));
 }
 
 //----------------------------------------------------------------------------//
@@ -353,7 +354,8 @@ void IsDynamicRequest::cacheResult(bool value) const {
   // Add an attribute for printing
   if (value && !decl->getAttrs().hasAttribute<DynamicAttr>() &&
         ABIRoleInfo(decl).providesAPI())
-    decl->getAttrs().add(new (decl->getASTContext()) DynamicAttr(/*Implicit=*/true));
+    decl->addAttribute(new (decl->getASTContext())
+                           DynamicAttr(/*Implicit=*/true));
 }
 
 //----------------------------------------------------------------------------//
@@ -867,10 +869,9 @@ void IsAccessorTransparentRequest::cacheResult(bool value) const {
 
   // For interface printing, API diff, etc.
   if (value) {
-    auto &attrs = accessor->getAttrs();
-    if (!attrs.hasAttribute<TransparentAttr>()) {
+    if (!accessor->getAttrs().hasAttribute<TransparentAttr>()) {
       auto &ctx = accessor->getASTContext();
-      attrs.add(new (ctx) TransparentAttr(/*IsImplicit=*/true));
+      accessor->addAttribute(new (ctx) TransparentAttr(/*IsImplicit=*/true));
     }
   }
 }

lib/ClangImporter/ClangDerivedConformances.cpp

@@ -1348,7 +1348,7 @@ void swift::conformToCxxSpanIfNeeded(ClangImporter::Implementation &impl,
 
   auto attr = AvailableAttr::createUniversallyDeprecated(
       importedConstructor->getASTContext(), "use 'init(_:)' instead.", "");
-  importedConstructor->getAttrs().add(attr);
+  importedConstructor->addAttribute(attr);
 
   decl->addMember(importedConstructor);
 

lib/ClangImporter/ClangImporter.cpp

@@ -3839,11 +3839,10 @@ ImportDecl *swift::createImportDecl(ASTContext &Ctx,
                                 ImportKind::Module, SourceLoc(),
                                 importPath.get(), ClangN);
   if (Ctx.ClangImporterOpts.BridgingHeaderIsInternal) {
-    ID->getAttrs().add(
-        new (Ctx) AccessControlAttr(SourceLoc(), SourceRange(),
-                                    AccessLevel::Internal, /*implicit=*/true));
+    ID->addAttribute(new (Ctx) AccessControlAttr(
+        SourceLoc(), SourceRange(), AccessLevel::Internal, /*implicit=*/true));
   } else if (IsExported) {
-    ID->getAttrs().add(new (Ctx) ExportedAttr(/*IsImplicit=*/false));
+    ID->addAttribute(new (Ctx) ExportedAttr(/*IsImplicit=*/false));
   }
   return ID;
 }
@@ -6263,39 +6262,39 @@ makeBaseClassMemberAccessors(DeclContext *declContext,
 
 // Clone attributes that have been imported from Clang.
 void cloneImportedAttributes(ValueDecl *fromDecl, ValueDecl* toDecl) {
-  ASTContext& context = fromDecl->getASTContext();
-  DeclAttributes& attrs = toDecl->getAttrs();
+  ASTContext &context = fromDecl->getASTContext();
   for (auto attr : fromDecl->getAttrs()) {
     switch (attr->getKind()) {
     case DeclAttrKind::Available: {
-      attrs.add(cast<AvailableAttr>(attr)->clone(context, true));
+      toDecl->addAttribute(cast<AvailableAttr>(attr)->clone(context, true));
       break;
     }
     case DeclAttrKind::Custom: {
       CustomAttr *cAttr = cast<CustomAttr>(attr);
-      attrs.add(CustomAttr::create(context, SourceLoc(), cAttr->getTypeExpr(),
-                                   /*owner*/ toDecl, cAttr->getInitContext(),
-                                   cAttr->getArgs(), /*implicit*/ true));
+      toDecl->addAttribute(
+          CustomAttr::create(context, SourceLoc(), cAttr->getTypeExpr(),
+                             /*owner*/ toDecl, cAttr->getInitContext(),
+                             cAttr->getArgs(), /*implicit*/ true));
       break;
     }
     case DeclAttrKind::DiscardableResult: {
-      attrs.add(new (context) DiscardableResultAttr(true));
+      toDecl->addAttribute(new (context) DiscardableResultAttr(true));
       break;
     }
     case DeclAttrKind::Effects: {
-      attrs.add(cast<EffectsAttr>(attr)->clone(context));
+      toDecl->addAttribute(cast<EffectsAttr>(attr)->clone(context));
       break;
     }
     case DeclAttrKind::Final: {
-      attrs.add(new (context) FinalAttr(true));
+      toDecl->addAttribute(new (context) FinalAttr(true));
       break;
     }
     case DeclAttrKind::Transparent: {
-      attrs.add(new (context) TransparentAttr(true));
+      toDecl->addAttribute(new (context) TransparentAttr(true));
       break;
     }
     case DeclAttrKind::WarnUnqualifiedAccess: {
-      attrs.add(new (context) WarnUnqualifiedAccessAttr(true));
+      toDecl->addAttribute(new (context) WarnUnqualifiedAccessAttr(true));
       break;
     }
     default:
@@ -7598,8 +7597,8 @@ static ValueDecl *addThunkForDependentTypes(FuncDecl *oldDecl,
   newFnDecl->setBodySynthesizer(synthesizeDependentTypeThunkParamForwarding, newDecl);
   newFnDecl->setSelfAccessKind(newDecl->getSelfAccessKind());
   if (newDecl->isStatic()) newFnDecl->setStatic();
-  newFnDecl->getAttrs().add(
-      new (newDecl->getASTContext()) TransparentAttr(/*IsImplicit=*/true));
+  newFnDecl->addAttribute(new (newDecl->getASTContext())
+                              TransparentAttr(/*IsImplicit=*/true));
   return newFnDecl;
 }
 
@@ -7725,8 +7724,8 @@ static ValueDecl *generateThunkForExtraMetatypes(SubstitutionMap subst,
   thunk->setBodySynthesizer(synthesizeForwardingThunkBody, newDecl);
   thunk->setSelfAccessKind(newDecl->getSelfAccessKind());
   if (newDecl->isStatic()) thunk->setStatic();
-  thunk->getAttrs().add(
-      new (newDecl->getASTContext()) TransparentAttr(/*IsImplicit=*/true));
+  thunk->addAttribute(new (newDecl->getASTContext())
+                          TransparentAttr(/*IsImplicit=*/true));
 
   return thunk;
 }
@@ -8998,7 +8997,7 @@ void ClangInheritanceInfo::setUnavailableIfNecessary(
     msg = "this base member is not accessible because of private inheritance";
 
   if (msg)
-    clonedDecl->getAttrs().add(AvailableAttr::createUniversallyUnavailable(
+    clonedDecl->addAttribute(AvailableAttr::createUniversallyUnavailable(
         clonedDecl->getASTContext(), msg));
 }