ManualOwnership: provide ability to apply to entire compilation unit

With this radar, we're flipping the polarity of things.

The flag `-enable-experimental-feature ManualOwnership` now turns on the diagnostics,
but they're all silenced by default. So, you need to add -Wwarning or -Werror to
your build settings to turn on the specific diagnostics you care about.

These are the diagnostic groups relevant to the feature:

- SemanticCopies aka "explicit copies mode"
- DynamicExclusivity

For example, the build setting `-Werror SemanticCopies` now gives you errors about
explicit copies, just as before, but now you can make them just warnings with -Wwarning.

To opt-out a declaration from everything when using the feature, use @_noManualOwnership.

@_manualOwnership is no longer an attribute as a result.

resolves rdar://163372569

Author: kavon

include/swift/AST/DeclAttr.def

@@ -815,7 +815,7 @@ SIMPLE_DECL_ATTR(_noObjCBridging, NoObjCBridging,
   UserInaccessible | ABIStableToAdd | ABIStableToRemove | APIStableToAdd | APIStableToRemove | ForbiddenInABIAttr,
   155)
 
-SIMPLE_DECL_ATTR(_manualOwnership, ManualOwnership,
+SIMPLE_DECL_ATTR(_noManualOwnership, NoManualOwnership,
   OnAbstractFunction | OnSubscript,
   UserInaccessible | ABIStableToAdd | ABIStableToRemove | APIStableToAdd | APIStableToRemove | ForbiddenInABIAttr,
   156)

include/swift/AST/DiagnosticsSema.def

@@ -2140,9 +2140,7 @@ ERROR(attr_static_exclusive_only_mutating,none,
 ERROR(attr_static_exclusive_no_setters,none,
       "variable of type %0 must not have a setter", (Type))
 
-// @_manualOwnership
-ERROR(attr_manual_ownership_experimental,none,
-      "'@_manualOwnership' requires '-enable-experimental-feature ManualOwnership'", ())
+// ManualOwnership
 ERROR(attr_manual_ownership_noimplicitcopy,none,
       "'@_noImplicitCopy' cannot be used with ManualOwnership", ())
 

include/swift/Basic/Features.def

@@ -452,7 +452,9 @@ EXPERIMENTAL_FEATURE(LifetimeDependence, true)
 /// Enable the `@_staticExclusiveOnly` attribute.
 EXPERIMENTAL_FEATURE(StaticExclusiveOnly, true)
 
-/// Enable the `@_manualOwnership` attribute.
+/// Enable the ManualOwnership diagnostic groups:
+///   * -Wwarning SemanticCopies
+///   * -Wwarning DynamicExclusivity
 EXPERIMENTAL_FEATURE(ManualOwnership, false)
 
 /// Enable the @extractConstantsFromMembers attribute.

lib/AST/ASTDumper.cpp

@@ -5024,7 +5024,7 @@ class PrintAttribute : public AttributeVisitor<PrintAttribute, void, Label>,
   TRIVIAL_ATTR_PRINTER(NoLocks, no_locks)
   TRIVIAL_ATTR_PRINTER(NoMetadata, no_metadata)
   TRIVIAL_ATTR_PRINTER(NoObjCBridging, no_objc_bridging)
-  TRIVIAL_ATTR_PRINTER(ManualOwnership, manual_ownership)
+  TRIVIAL_ATTR_PRINTER(NoManualOwnership, no_manual_ownership)
   TRIVIAL_ATTR_PRINTER(NoRuntime, no_runtime)
   TRIVIAL_ATTR_PRINTER(NonEphemeral, non_ephemeral)
   TRIVIAL_ATTR_PRINTER(NonEscapable, non_escapable)

lib/ASTGen/Sources/ASTGen/DeclAttrs.swift

@@ -265,7 +265,6 @@ extension ASTGenVisitor {
         .LexicalLifetimes,
         .LLDBDebuggerFunction,
         .MainType,
-        .ManualOwnership,
         .Marker,
         .MoveOnly,
         .NeverEmitIntoClient,
@@ -276,6 +275,7 @@ extension ASTGenVisitor {
         .NoRuntime,
         .NoImplicitCopy,
         .NoLocks,
+        .NoManualOwnership,
         .NoMetadata,
         .NoObjCBridging,
         .NonEphemeral,

lib/SIL/IR/SILFunctionBuilder.cpp

@@ -204,7 +204,8 @@ void SILFunctionBuilder::addFunctionAttributes(
     F->setPerfConstraints(PerformanceConstraints::NoExistentials);
   } else if (Attrs.hasAttribute<NoObjCBridgingAttr>()) {
     F->setPerfConstraints(PerformanceConstraints::NoObjCBridging);
-  } else if (Attrs.hasAttribute<ManualOwnershipAttr>()) {
+  } else if (constant && constant.hasDecl() && !constant.isImplicit() &&
+             !Attrs.hasAttribute<NoManualOwnershipAttr>()) {
     F->setPerfConstraints(PerformanceConstraints::ManualOwnership);
   }
 

lib/SILGen/SILGen.cpp

@@ -1368,15 +1368,15 @@ void SILGenModule::preEmitFunction(SILDeclRef constant, SILFunction *F,
   //
   // If ManualOwnership ends up subsuming those prior mechanisms for an
   // explicit-copy mode, we can move this somewhere else, like postEmitFunction.
-  if (auto *ace = constant.getAbstractClosureExpr()) {
-    if (auto *dc = ace->getOutermostFunctionContext()) {
-      if (auto *decl = dc->getAsDecl()) {
-        if (decl->getAttrs().hasAttribute<ManualOwnershipAttr>()) {
-          F->setPerfConstraints(PerformanceConstraints::ManualOwnership);
-        }
-      }
-    }
-  }
+  //
+  // FIXME: maybe this should happen in SILFunctionBuilder::getOrCreateFunction
+  if (getASTContext().LangOpts.hasFeature(Feature::ManualOwnership))
+    if (auto *ace = constant.getAbstractClosureExpr())
+      if (auto *dc = ace->getOutermostFunctionContext())
+        if (auto *decl = dc->getAsDecl())
+          if (!decl->isImplicit() &&
+              !decl->getAttrs().hasAttribute<NoManualOwnershipAttr>())
+            F->setPerfConstraints(PerformanceConstraints::ManualOwnership);
 
   LLVM_DEBUG(llvm::dbgs() << "lowering ";
              F->printName(llvm::dbgs());

lib/Sema/TypeCheckAttr.cpp

@@ -183,6 +183,7 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
   IGNORED_ATTR(NoAllocation)
   IGNORED_ATTR(NoRuntime)
   IGNORED_ATTR(NoExistentials)
+  IGNORED_ATTR(NoManualOwnership)
   IGNORED_ATTR(NoObjCBridging)
   IGNORED_ATTR(EmitAssemblyVisionRemarks)
   IGNORED_ATTR(ShowInInterface)
@@ -476,7 +477,6 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
   void visitUnsafeNonEscapableResultAttr(UnsafeNonEscapableResultAttr *attr);
 
   void visitStaticExclusiveOnlyAttr(StaticExclusiveOnlyAttr *attr);
-  void visitManualOwnershipAttr(ManualOwnershipAttr *attr);
   void visitWeakLinkedAttr(WeakLinkedAttr *attr);
   void visitSILGenNameAttr(SILGenNameAttr *attr);
   void visitLifetimeAttr(LifetimeAttr *attr);
@@ -8424,13 +8424,6 @@ void AttributeChecker::visitStaticExclusiveOnlyAttr(
   }
 }
 
-void AttributeChecker::visitManualOwnershipAttr(ManualOwnershipAttr *attr) {
-  if (Ctx.LangOpts.hasFeature(Feature::ManualOwnership))
-    return;
-
-  diagnoseAndRemoveAttr(attr, diag::attr_manual_ownership_experimental);
-}
-
 void AttributeChecker::visitWeakLinkedAttr(WeakLinkedAttr *attr) {
   if (!Ctx.LangOpts.Target.isOSBinFormatCOFF())
     return;

lib/Sema/TypeCheckDeclOverride.cpp

@@ -1620,8 +1620,8 @@ namespace  {
     UNINTERESTING_ATTR(NoAllocation)
     UNINTERESTING_ATTR(NoRuntime)
     UNINTERESTING_ATTR(NoExistentials)
+    UNINTERESTING_ATTR(NoManualOwnership)
     UNINTERESTING_ATTR(NoObjCBridging)
-    UNINTERESTING_ATTR(ManualOwnership)
     UNINTERESTING_ATTR(Inlinable)
     UNINTERESTING_ATTR(Effects)
     UNINTERESTING_ATTR(Expose)