Merge pull request swiftlang#78554 from DougGregor/unsafe-effect

Author: DougGregor

include/swift/AST/ASTBridging.h

@@ -1505,6 +1505,11 @@ BridgedUnresolvedSpecializeExpr BridgedUnresolvedSpecializeExpr_createParsed(
     BridgedSourceLoc cLAngleLoc, BridgedArrayRef cArguments,
     BridgedSourceLoc cRAngleLoc);
 
+SWIFT_NAME("BridgedUnsafeExpr.createParsed(_:unsafeLoc:subExpr:)")
+BridgedUnsafeExpr BridgedUnsafeExpr_createParsed(BridgedASTContext cContext,
+                                                 BridgedSourceLoc cUnsafeLoc,
+                                                 BridgedExpr cSubExpr);
+
 SWIFT_NAME("BridgedInOutExpr.createParsed(_:loc:subExpr:)")
 BridgedInOutExpr BridgedInOutExpr_createParsed(BridgedASTContext cContext,
                                                BridgedSourceLoc cLoc,

include/swift/AST/Attr.h

@@ -2830,26 +2830,6 @@ class RawLayoutAttr final : public DeclAttribute {
   UNIMPLEMENTED_CLONE(RawLayoutAttr)
 };
 
-class SafeAttr final : public DeclAttribute {
-public:
-  /// The optional message.
-  const StringRef message;
-
-  SafeAttr(SourceLoc atLoc, SourceRange range, StringRef message,
-           bool isImplicit = false)
-      : DeclAttribute(DeclAttrKind::Safe, atLoc, range, isImplicit),
-        message(message) { }
-
-  static bool classof(const DeclAttribute *DA) {
-    return DA->getKind() == DeclAttrKind::Safe;
-  }
-
-  /// Create a copy of this attribute.
-  SafeAttr *clone(ASTContext &ctx) const {
-    return new (ctx) SafeAttr(AtLoc, Range, message, isImplicit());
-  }
-};
-
 class LifetimeAttr final : public DeclAttribute {
   LifetimeEntry *entry;
 

include/swift/AST/AvailabilityContext.h

@@ -87,10 +87,6 @@ class AvailabilityContext {
   /// Returns true if this context is `@_unavailableInEmbedded`.
   bool isUnavailableInEmbedded() const;
 
-  /// Returns true if this context allows the use of unsafe constructs inside
-  /// it.
-  bool allowsUnsafe() const;
-
   /// Constrain with another `AvailabilityContext`.
   void constrainWithContext(const AvailabilityContext &other, ASTContext &ctx);
 
@@ -107,9 +103,6 @@ class AvailabilityContext {
   constrainWithDeclAndPlatformRange(const Decl *decl,
                                     const AvailabilityRange &platformRange);
 
-  /// Constrain to allow unsafe code.
-  void constrainWithAllowsUnsafe(ASTContext &ctx);
-
   /// Returns true if `other` is as available or is more available.
   bool isContainedIn(const AvailabilityContext other) const;
 

include/swift/AST/AvailabilityContextStorage.h

@@ -43,10 +43,6 @@ struct AvailabilityContext::PlatformInfo {
   /// platform.
   unsigned IsDeprecated : 1;
 
-  /// Whether or not the context allows unsafe code within it, e.g., via the
-  /// `@unsafe` attribute.
-  unsigned AllowsUnsafe: 1;
-
   /// Sets each field to the value of the corresponding field in `other` if the
   /// other is more restrictive. Returns true if any field changed as a result
   /// of adding this constraint.
@@ -67,7 +63,6 @@ struct AvailabilityContext::PlatformInfo {
     ID.AddBoolean(IsUnavailableInEmbedded);
     ID.AddInteger(static_cast<uint8_t>(UnavailablePlatform));
     ID.AddBoolean(IsDeprecated);
-    ID.AddBoolean(AllowsUnsafe);
   }
 };
 

include/swift/AST/Decl.h

@@ -1207,10 +1207,6 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl>, public Swi
   /// used in a "safe" dialect.
   bool isUnsafe() const;
 
-  /// Whether this declaration explicitly states that it is allowed to contain
-  /// unsafe code.
-  bool allowsUnsafe() const;
-
 private:
   bool isUnsafeComputed() const {
     return Bits.Decl.IsUnsafeComputed;
@@ -1824,10 +1820,6 @@ struct InheritedEntry : public TypeLoc {
     return getOptions().contains(ProtocolConformanceFlags::Unsafe);
   }
 
-  bool isSafe() const {
-    return getOptions().contains(ProtocolConformanceFlags::Safe);
-  }
-
   bool isSuppressed() const { return IsSuppressed; }
 
   void setOption(ProtocolConformanceFlags flag) {
@@ -1957,7 +1949,6 @@ class ExtensionDecl final : public GenericContext, public Decl,
   friend class Decl;
 public:
   using Decl::getASTContext;
-  using Decl::allowsUnsafe;
 
   /// Create a new extension declaration.
   static ExtensionDecl *create(ASTContext &ctx, SourceLoc extensionLoc,
@@ -3435,7 +3426,6 @@ class GenericTypeDecl : public GenericContext, public TypeDecl {
   using DeclContext::operator new;
   using DeclContext::operator delete;
   using TypeDecl::getDeclaredInterfaceType;
-  using Decl::allowsUnsafe;
 
   static bool classof(const DeclContext *C) {
     if (auto D = C->getAsDecl())

include/swift/AST/DeclAttr.def

@@ -531,11 +531,7 @@ SIMPLE_DECL_ATTR(_addressableForDependencies, AddressableForDependencies,
   OnNominalType | ABIBreakingToAdd | ABIBreakingToRemove | APIBreakingToAdd | APIBreakingToRemove | UserInaccessible,
   163)
 
-DECL_ATTR(safe, Safe,
-  OnAbstractFunction | OnSubscript | OnVar | OnMacro | OnNominalType |
-  OnExtension | OnTypeAlias | OnImport | UserInaccessible |
-  ABIStableToAdd | ABIStableToRemove | APIBreakingToAdd | APIStableToRemove,
-  164)
+// 164 was the never-shipped @safe attribute and can be reused
 
 DECL_ATTR(abi, ABI,
   OnAbstractFunction | OnVar /* will eventually add types */ | LongAttribute | ABIStableToAdd | ABIStableToRemove | APIStableToAdd | APIStableToRemove,

include/swift/AST/DeclContext.h

@@ -718,10 +718,6 @@ class alignas(1 << DeclContextAlignInBits) DeclContext
   /// target. Used for conformance lookup disambiguation.
   bool isAlwaysAvailableConformanceContext() const;
 
-  /// Determines whether this context is explicitly allowed to use unsafe
-  /// constructs.
-  bool allowsUnsafe() const;
-
   /// \returns true if traversal was aborted, false otherwise.
   bool walkContext(ASTWalker &Walker);
 

include/swift/AST/DiagnosticsParse.def

@@ -1371,6 +1371,8 @@ ERROR(expected_expr_after_ternary_colon,none,
       "expected expression after '? ... :' in ternary expression", ())
 ERROR(expected_expr_after_await, none,
       "expected expression after 'await'", ())
+ERROR(expected_expr_after_unsafe, none,
+      "expected expression after 'unsafe'", ())
 ERROR(expected_expr_after_move, none,
       "expected expression after 'consume'", ())
 ERROR(expected_expr_after_copy, none,
@@ -2109,9 +2111,6 @@ ERROR(parser_new_parser_errors,none,
       "new Swift parser generated errors for code that C++ parser accepted",
        ())
 
-ERROR(safe_attr_unchecked,none,
-      "'@safe' attribute must be written as '@safe(unchecked)'", ())
-
 // MARK: Reference Binding Diagnostics
 ERROR(sil_markuncheckedreferencebinding_requires_attribute,none,
       "mark_unchecked_reference_binding requires an attribute like [inout]", ())

include/swift/AST/DiagnosticsSema.def

@@ -4523,7 +4523,7 @@ WARNING(nan_comparison_both_nan, none,
        (StringRef, bool))
 
 // If you change this, also change enum TryKindForDiagnostics.
-#define TRY_KIND_SELECT(SUB) "%select{try|try!|try?|await}" #SUB
+#define TRY_KIND_SELECT(SUB) "%select{try|try!|try?|await|unsafe}" #SUB
 
 ERROR(try_rhs,none,
       "'" TRY_KIND_SELECT(0) "' cannot appear to the right of a "
@@ -8079,11 +8079,6 @@ NOTE(sending_function_result_with_sending_param_note, none,
 ERROR(unsafe_attr_disabled,none,
       "attribute requires '-enable-experimental-feature AllowUnsafeAttribute'", ())
 
-GROUPED_WARNING(decl_involves_unsafe,Unsafe,none,
-      "%kindbase0 involves unsafe code; "
-      "use %select{'@unsafe' to indicate that its use is not memory-safe|"
-      "'@safe(unchecked)' to assert that the code is memory-safe}1",
-      (const Decl *, bool))
 NOTE(note_reference_to_unsafe_decl,none,
       "%select{reference|call}0 to unsafe %kind1",
       (bool, const ValueDecl *))
@@ -8103,6 +8098,12 @@ NOTE(note_reference_exclusivity_unchecked,none,
 NOTE(note_use_of_unsafe_conformance_is_unsafe,none,
      "@unsafe conformance of %0 to %kind1 involves unsafe code",
      (Type, const ValueDecl *))
+
+GROUPED_WARNING(decl_signature_involves_unsafe,Unsafe,none,
+      "%kindbase0 has an interface that is not memory-safe; "
+      "use '@unsafe' to indicate that its use is unsafe",
+      (const Decl *))
+
 GROUPED_WARNING(conformance_involves_unsafe,Unsafe,none,
      "conformance of %0 to %kind1 involves unsafe code; use '@unsafe' to "
      "indicate that the conformance is not memory-safe",
@@ -8114,44 +8115,19 @@ NOTE(note_type_witness_unsafe,none,
       "unsafe type %0 cannot satisfy safe associated type %1",
       (Type, DeclName))
 
-GROUPED_WARNING(override_safe_withunsafe,Unsafe,none,
+GROUPED_WARNING(override_safe_with_unsafe,Unsafe,none,
       "override of safe %0 with unsafe %0", (DescriptiveDeclKind))
-GROUPED_WARNING(use_of_unsafe_conformance_is_unsafe,Unsafe,none,
-      "@unsafe conformance of %0 to %kind1 involves unsafe code",
-       (Type, const ValueDecl *))
-GROUPED_WARNING(reference_unowned_unsafe,Unsafe,none,
-      "reference to unowned(unsafe) %kind0 is unsafe", (const ValueDecl *))
-GROUPED_WARNING(reference_exclusivity_unchecked,Unsafe,none,
-      "reference to @exclusivity(unchecked) %kind0 is unsafe", (const ValueDecl *))
-
-GROUPED_WARNING(reference_to_nonisolated_unsafe,Unsafe,none,
-      "reference to nonisolated(unsafe) %kind0 is unsafe in concurrently-executing code",
-       (const ValueDecl *))
-GROUPED_WARNING(reference_to_unsafe_decl,Unsafe,none,
-      "%select{reference|call}0 to unsafe %kindbase1",
-      (bool, const ValueDecl *))
-GROUPED_WARNING(reference_to_unsafe_typed_decl,Unsafe,none,
-      "%select{reference|call}0 to %kindbase1 involves unsafe type %2",
-      (bool, const ValueDecl *, Type))
-GROUPED_WARNING(reference_to_unsafe_through_typealias,Unsafe,none,
-     "reference to %kind0 whose underlying type involves unsafe type %1",
-     (const ValueDecl *, Type))
+
 GROUPED_WARNING(preconcurrency_import_unsafe,Unsafe,none,
       "@preconcurrency import is not memory-safe because it can silently "
-      "introduce data races; use '@safe(unchecked)' to assert that the "
-      "code is memory-safe", ())
-NOTE(encapsulate_unsafe_in_enclosing_context,none,
-     "make %kindbase0 @safe(unchecked) to allow it to use unsafe constructs in its definition",
-     (const Decl *))
-NOTE(make_enclosing_context_unsafe,none,
-     "make %kindbase0 @unsafe to indicate that its use is not memory-safe",
-     (const Decl *))
+      "introduce data races", ())
+GROUPED_WARNING(unsafe_without_unsafe,Unsafe,none,
+      "expression uses unsafe constructs but is not marked with 'unsafe'", ())
+WARNING(no_unsafe_in_unsafe,none,
+        "no unsafe operations occur within 'unsafe' expression", ())
 NOTE(make_subclass_unsafe,none,
      "make class %0 @unsafe to allow unsafe overrides of safe superclass methods",
      (DeclName))
-NOTE(make_conforming_context_unsafe,none,
-     "make the enclosing %0 @unsafe to allow unsafe conformance to protocol %1",
-     (DescriptiveDeclKind, DeclName))
 
 //===----------------------------------------------------------------------===//
 // MARK: Value Generics

include/swift/AST/Effects.h

@@ -40,7 +40,8 @@ class ProtocolDecl;
 
 enum class EffectKind : uint8_t {
   Throws = 1 << 0,
-  Async  = 1 << 1
+  Async  = 1 << 1,
+  Unsafe = 1 << 2,
 };
 using PossibleEffects = OptionSet<EffectKind>;