Merge pull request #3972 from swiftwasm/main

[pull] swiftwasm from main

Author: pull[bot]

docs/DifferentiableProgramming.md

@@ -698,7 +698,7 @@ differentiation: given an "original function" to differentiate, a derivative
 function is generated by replacing function applications in the original
 function with corresponding derivative function applications. The algorithm is
 described in detail in the
-[Swift Differentiable Programming Implementation Overview document](http://bit.ly/swift-autodiff-internals).
+[Swift Differentiable Programming Implementation Overview](DifferentiableProgrammingImplementation.md).
 
 Some languages provide the ability to define custom code transformations:
 

docs/DifferentiableProgrammingImplementation.md

@@ -1231,6 +1231,11 @@ class ASTContext final {
   bool isRecursivelyConstructingRequirementMachine(
       CanGenericSignature sig);
 
+  /// This is a hack to break cycles. Don't introduce new callers of this
+  /// method.
+  bool isRecursivelyConstructingRequirementMachine(
+      const ProtocolDecl *proto);
+
   /// Retrieve a generic signature with a single unconstrained type parameter,
   /// like `<T>`.
   CanGenericSignature getSingleGenericParameterSignature() const;

docs/assets/DifferentiableProgrammingImplementation/differentiation-control-flow.png

@@ -699,7 +699,7 @@ CONTEXTUAL_SIMPLE_DECL_ATTR(_const, CompileTimeConst,
   ABIStableToAdd | ABIStableToRemove | APIBreakingToAdd | APIStableToRemove,
   126)
 
-SIMPLE_DECL_ATTR(_unavailableFromAsync, UnavailableFromAsync,
+DECL_ATTR(_unavailableFromAsync, UnavailableFromAsync,
   OnFunc | OnConstructor | UserInaccessible |
   ABIStableToAdd | ABIStableToRemove |
   APIBreakingToAdd | APIStableToRemove,

docs/assets/DifferentiableProgrammingImplementation/swift-compilation-pipeline.png

@@ -2085,6 +2085,26 @@ class TypeSequenceAttr : public DeclAttribute {
   }
 };
 
+/// The @_unavailableFromAsync attribute, used to make function declarations
+/// unavailable from async contexts.
+class UnavailableFromAsyncAttr : public DeclAttribute {
+public:
+  UnavailableFromAsyncAttr(StringRef Message, SourceLoc AtLoc,
+                           SourceRange Range, bool Implicit)
+      : DeclAttribute(DAK_UnavailableFromAsync, AtLoc, Range, Implicit),
+        Message(Message) {}
+  UnavailableFromAsyncAttr(StringRef Message, bool Implicit)
+      : UnavailableFromAsyncAttr(Message, SourceLoc(), SourceRange(),
+                                 Implicit) {}
+  const StringRef Message;
+
+  bool hasMessage() const { return !Message.empty(); }
+
+  static bool classof(const DeclAttribute *DA) {
+    return DA->getKind() == DAK_UnavailableFromAsync;
+  }
+};
+
 /// Attributes that may be applied to declarations.
 class DeclAttributes {
   /// Linked list of declaration attributes.

include/swift/AST/ASTContext.h

@@ -1435,6 +1435,8 @@ ERROR(attr_missing_label,PointsToFirstBadToken,
       "missing label '%0:' in '@%1' attribute", (StringRef, StringRef))
 ERROR(attr_expected_label,none,
       "expected label '%0:' in '@%1' attribute", (StringRef, StringRef))
+ERROR(attr_expected_colon_after_label,none,
+      "expected ':' after label '%0'", (StringRef))
 
 ERROR(alignment_must_be_positive_integer,none,
       "alignment value must be a positive integer literal", ())

include/swift/AST/Attr.def

@@ -4719,7 +4719,8 @@ ERROR(async_named_decl_must_be_available_from_async,none,
         "asynchronous %0 %1 must be available from asynchronous contexts",
         (DescriptiveDeclKind, DeclName))
 ERROR(async_unavailable_decl,none,
-      "%0 %1 is unavailable from asynchronous contexts", (DescriptiveDeclKind, DeclBaseName))
+      "%0 %1 is unavailable from asynchronous contexts%select{|; %3}2",
+      (DescriptiveDeclKind, DeclBaseName, bool, StringRef))
 
 //------------------------------------------------------------------------------
 // MARK: Type Check Types

include/swift/AST/Attr.h

@@ -2017,6 +2017,11 @@ bool ASTContext::isRecursivelyConstructingRequirementMachine(
   return getRewriteContext().isRecursivelyConstructingRequirementMachine(sig);
 }
 
+bool ASTContext::isRecursivelyConstructingRequirementMachine(
+      const ProtocolDecl *proto) {
+  return getRewriteContext().isRecursivelyConstructingRequirementMachine(proto);
+}
+
 Optional<llvm::TinyPtrVector<ValueDecl *>>
 OverriddenDeclsRequest::getCachedResult() const {
   auto decl = std::get<0>(getStorage());