Merge pull request swiftlang#14809 from jckarter/keypath-resilience

External key path components and key path descriptors

Author: jckarter

docs/ABI/KeyPaths.md

@@ -25,7 +25,7 @@ by previous ABI-stable versions of the Swift compiler.
 ### Buffer Header
 
 Key path objects begin with the standard Swift heap object header, followed by a
-key path object header. Relative to the start of the heap object header:
+key path object header. Relative to the end of the heap object header:
 
 Offset  | Description
 ------- | ----------------------------------------------
@@ -40,7 +40,7 @@ following bit fields:
 Bits (LSB zero) | Description
 --------------- | -----------
 0...23          | **Buffer size** in bytes
-24...29         | Reserved. Must be zero in Swift 4 runtime
+24...29         | Reserved. Must be zero in Swift 4...5 runtime
 30              | 1 = Has **reference prefix**, 0 = No reference prefix
 31              | 1 = Is **trivial**, 0 = Has destructor
 
@@ -63,8 +63,8 @@ describing the following component.
 
 Bits (LSB zero) | Description
 --------------- | -----------
-0...28          | **Payload** (meaning is dependent on component kind)
-29...30         | **Component kind**
+0...23          | **Payload** (meaning is dependent on component kind)
+24...30         | **Component kind**
 31              | 1 = **End of reference prefix**, 0 = Not end of reference prefix
 
 If the key path has a *reference prefix*, then exactly one component must have
@@ -73,27 +73,27 @@ that the component after the end of the reference prefix will initiate mutation.
 
 The following *component kinds* are recognized:
 
-Value in bit 30&29 | Description
------------------- | -----------
-0                  | Struct/tuple/self stored property
-1                  | Computed
-2                  | Class stored property
-3                  | Optional chaining/forcing/wrapping
+Value in bits 24...30 | Description
+--------------------- | -----------
+0                     | Struct/tuple/self stored property
+1                     | Computed
+2                     | Class stored property
+3                     | Optional chaining/forcing/wrapping
 
 - A **struct stored property** component, when given
   a value of the base type in memory, can project the component value in-place
   at a fixed offset within the base value. This applies for struct stored
   properties, tuple fields, and the `.self` identity component (which trivially
   projects at offset zero). The
   *payload* contains the offset in bytes of the projected field in the
-  aggregate, or the special value `0x1FFF_FFFF`, which indicates that the
+  aggregate, or the special value `0xFF_FFFF`, which indicates that the
   offset is too large to pack into the payload and is stored in the next 32 bits
   after the header.
 - A **class stored property** component, when given a reference to a class
   instance, can project the component value inside the class instance at
   a fixed offset. The *payload*
   *payload* contains the offset in bytes of the projected field from the
-  address point of the object, or the special value `0x1FFF_FFFF`, which
+  address point of the object, or the special value `0xFF_FFFF`, which
   indicates that the offset is too large to pack into the payload and is stored
   in the next 32 bits after the header.
 - An **optional** component performs an operation involving `Optional` values.

include/swift/ABI/KeyPath.h

@@ -204,6 +204,13 @@ class KeyPathComponentHeader {
                     : getResolutionStrategy(idKind)));
   }
 
+  constexpr static KeyPathComponentHeader
+  forExternalComponent() {
+    return KeyPathComponentHeader(
+      _SwiftKeyPathComponentHeader_ExternalTag
+      << _SwiftKeyPathComponentHeader_DiscriminatorShift);
+  }
+  
   constexpr uint32_t getData() const { return Data; }
 };
 

include/swift/AST/DiagnosticsParse.def

@@ -528,6 +528,8 @@ ERROR(expected_sil_instr_opcode,none,
       "expected SIL instruction opcode", ())
 ERROR(expected_tok_in_sil_instr,none,
       "expected '%0' in SIL instruction", (StringRef))
+ERROR(sil_property_generic_signature_mismatch,none,
+      "sil_property generic signature must match original declaration", ())
 ERROR(sil_string_no_encoding,none,
       "string_literal instruction requires an encoding", ())
 ERROR(sil_string_invalid_encoding,none,

include/swift/AST/GenericEnvironment.h

@@ -29,12 +29,25 @@
 
 namespace swift {
 
+class ArchetypeType;
 class GenericSignatureBuilder;
 class ASTContext;
 class GenericTypeParamType;
 class SILModule;
 class SILType;
 
+/// Query function suitable for use as a \c TypeSubstitutionFn that queries
+/// the mapping of interface types to archetypes.
+class QueryInterfaceTypeSubstitutions {
+  const GenericEnvironment *self;
+  
+public:
+  QueryInterfaceTypeSubstitutions(const GenericEnvironment *self)
+  : self(self) { }
+  
+  Type operator()(SubstitutableType *type) const;
+};
+
 /// Describes the mapping between archetypes and interface types for the
 /// generic parameters of a DeclContext.
 ///
@@ -66,23 +79,12 @@ class alignas(1 << DeclAlignInBits) GenericEnvironment final
   GenericEnvironment(GenericSignature *signature,
                      GenericSignatureBuilder *builder);
 
-  friend class ArchetypeType;
-  friend class GenericSignatureBuilder;
+  friend ArchetypeType;
+  friend GenericSignatureBuilder;
 
   GenericSignatureBuilder *getGenericSignatureBuilder() const { return Builder; }
 
-  /// Query function suitable for use as a \c TypeSubstitutionFn that queries
-  /// the mapping of interface types to archetypes.
-  class QueryInterfaceTypeSubstitutions {
-    const GenericEnvironment *self;
-
-  public:
-    QueryInterfaceTypeSubstitutions(const GenericEnvironment *self)
-      : self(self) { }
-
-    Type operator()(SubstitutableType *type) const;
-  };
-  friend class QueryInterfaceTypeSubstitutions;
+  friend QueryInterfaceTypeSubstitutions;
 
 public:
   GenericSignature *getGenericSignature() const {

include/swift/AST/GenericSignature.h

@@ -17,6 +17,7 @@
 #ifndef SWIFT_AST_GENERIC_SIGNATURE_H
 #define SWIFT_AST_GENERIC_SIGNATURE_H
 
+#include "swift/AST/PrintOptions.h"
 #include "swift/AST/Requirement.h"
 #include "swift/AST/SubstitutionList.h"
 #include "swift/AST/Types.h"
@@ -338,7 +339,7 @@ class alignas(1 << TypeAlignInBits) GenericSignature final
                       TypeArrayView<GenericTypeParamType> genericParams,
                       ArrayRef<Requirement> requirements);
 
-  void print(raw_ostream &OS) const;
+  void print(raw_ostream &OS, PrintOptions Options = PrintOptions()) const;
   void dump() const;
   std::string getAsString() const;
 };

include/swift/AST/PrintOptions.h

@@ -18,6 +18,7 @@
 #include "swift/AST/Identifier.h"
 #include "swift/AST/TypeOrExtensionDecl.h"
 #include "llvm/ADT/Optional.h"
+#include "llvm/ADT/DenseMap.h"
 #include <limits.h>
 #include <vector>
 

include/swift/Basic/LangOptions.h

@@ -219,6 +219,9 @@ namespace swift {
     /// This is for bootstrapping. It can't be in SILOptions because the
     /// TypeChecker uses it to set resolve the ParameterConvention.
     bool EnableSILOpaqueValues = false;
+    
+    /// Enables key path resilience.
+    bool EnableKeyPathResilience = false;
 
     /// If set to true, the diagnosis engine can assume the emitted diagnostics
     /// will be used in editor. This usually leads to more aggressive fixit.

include/swift/Demangling/DemangleNodes.def

@@ -132,6 +132,7 @@ NODE(PartialApplyObjCForwarder)
 NODE(PostfixOperator)
 NODE(PrefixOperator)
 NODE(PrivateDeclName)
+NODE(PropertyDescriptor)
 CONTEXT_NODE(Protocol)
 NODE(ProtocolConformance)
 NODE(ProtocolDescriptor)

include/swift/IRGen/Linking.h

@@ -140,6 +140,10 @@ class LinkEntity {
     /// The pointer is a ClassDecl*.
     ClassMetadataBaseOffset,
 
+    /// The property descriptor for a public property or subscript.
+    /// The pointer is an AbstractStorageDecl*.
+    PropertyDescriptor,
+
     /// The nominal type descriptor for a nominal type.
     /// The pointer is a NominalTypeDecl*.
     NominalTypeDescriptor,
@@ -481,6 +485,12 @@ class LinkEntity {
     return entity;
   }
 
+  static LinkEntity forPropertyDescriptor(AbstractStorageDecl *decl) {
+    LinkEntity entity;
+    entity.setForDecl(Kind::PropertyDescriptor, decl);
+    return entity;
+  }
+
   static LinkEntity forModuleDescriptor(ModuleDecl *decl) {
     LinkEntity entity;
     entity.setForDecl(Kind::ModuleDescriptor, decl);

include/swift/Option/FrontendOptions.td

@@ -463,4 +463,7 @@ def enable_verify_exclusivity : Flag<["-"], "enable-verify-exclusivity">,
 def disable_verify_exclusivity : Flag<["-"], "disable-verify-exclusivity">,
   HelpText<"Diable verification of access markers used to enforce exclusivity.">;
 
+def enable_key_path_resilience : Flag<["-"], "enable-key-path-resilience">,
+  HelpText<"Enable key path resilience.">;
+
 } // end let Flags = [FrontendOption, NoDriverOption, HelpHidden]