Merge pull request swiftlang#80540 from swiftlang/revert-80452-lifetimeinout

Revert "Add support for inout lifetime dependence"

Author: artemcm

include/swift/AST/ASTBridging.h

@@ -1086,9 +1086,8 @@ BridgedInlineAttr BridgedInlineAttr_createParsed(BridgedASTContext cContext,
 
 enum ENUM_EXTENSIBILITY_ATTR(closed) BridgedParsedLifetimeDependenceKind {
   BridgedParsedLifetimeDependenceKindDefault,
-  BridgedParsedLifetimeDependenceKindBorrow,
+  BridgedParsedLifetimeDependenceKindScope,
   BridgedParsedLifetimeDependenceKindInherit,
-  BridgedParsedLifetimeDependenceKindInout
 };
 
 class BridgedLifetimeDescriptor {

include/swift/AST/DiagnosticsSema.def

@@ -8169,11 +8169,8 @@ ERROR(lifetime_dependence_invalid_inherit_escapable_type, none,
       "'@lifetime(borrow %0)' instead",
       (StringRef))
 ERROR(lifetime_dependence_cannot_use_parsed_borrow_consuming, none,
-      "invalid use of %0 dependence with %1 ownership",
-      (StringRef, StringRef))
-ERROR(lifetime_dependence_cannot_use_default_escapable_consuming, none,
-      "invalid lifetime dependence on an Escapable value with %0 ownership",
-      (StringRef))
+      "invalid use of borrow dependence with consuming ownership",
+      ())
 ERROR(lifetime_dependence_cannot_use_parsed_borrow_inout, none,
       "invalid use of borrow dependence on the same inout parameter",
       ())

include/swift/AST/LifetimeDependence.h

@@ -38,9 +38,8 @@ class SILResultInfo;
 
 enum class ParsedLifetimeDependenceKind : uint8_t {
   Default = 0,
-  Borrow,
-  Inherit, // Only used with deserialized decls
-  Inout
+  Scope,
+  Inherit // Only used with deserialized decls
 };
 
 enum class LifetimeDependenceKind : uint8_t { Inherit = 0, Scope };
@@ -183,7 +182,6 @@ class LifetimeEntry final
          ArrayRef<LifetimeDescriptor> sources,
          std::optional<LifetimeDescriptor> targetDescriptor = std::nullopt);
 
-  std::string getString() const;
   SourceLoc getLoc() const { return startLoc; }
   SourceLoc getStartLoc() const { return startLoc; }
   SourceLoc getEndLoc() const { return endLoc; }
@@ -195,6 +193,35 @@ class LifetimeEntry final
   std::optional<LifetimeDescriptor> getTargetDescriptor() const {
     return targetDescriptor;
   }
+
+  std::string getString() const {
+    std::string result = "@lifetime(";
+    if (targetDescriptor.has_value()) {
+      result += targetDescriptor->getString();
+      result += ": ";
+    }
+
+    bool firstElem = true;
+    for (auto source : getSources()) {
+      if (!firstElem) {
+        result += ", ";
+      }
+      switch (source.getParsedLifetimeDependenceKind()) {
+      case ParsedLifetimeDependenceKind::Scope:
+        result += "borrow ";
+        break;
+      case ParsedLifetimeDependenceKind::Inherit:
+        result += "copy ";
+        break;
+      default:
+        break;
+      }
+      result += source.getString();
+      firstElem = false;
+    }
+    result += ")";
+    return result;
+  }
 };
 
 class LifetimeDependenceInfo {
@@ -339,9 +366,6 @@ filterEscapableLifetimeDependencies(GenericSignature sig,
         SmallVectorImpl<LifetimeDependenceInfo> &outputs,
         llvm::function_ref<Type (unsigned targetIndex)> getSubstTargetType);
 
-StringRef
-getNameForParsedLifetimeDependenceKind(ParsedLifetimeDependenceKind kind);
-
 } // namespace swift
 
 #endif

include/swift/Basic/Features.def

@@ -416,9 +416,6 @@ EXPERIMENTAL_FEATURE(StructLetDestructuring, true)
 /// Enable returning non-escapable types from functions.
 EXPERIMENTAL_FEATURE(LifetimeDependence, true)
 
-/// Enable inout lifetime dependence - @lifetime(&arg)
-EXPERIMENTAL_FEATURE(InoutLifetimeDependence, true)
-
 /// Enable the `@_staticExclusiveOnly` attribute.
 EXPERIMENTAL_FEATURE(StaticExclusiveOnly, true)
 

lib/AST/Bridging/DeclAttributeBridging.cpp

@@ -470,12 +470,10 @@ unbridged(BridgedParsedLifetimeDependenceKind kind) {
   switch (kind) {
   case BridgedParsedLifetimeDependenceKindDefault:
     return swift::ParsedLifetimeDependenceKind::Default;
-  case BridgedParsedLifetimeDependenceKindBorrow:
-    return swift::ParsedLifetimeDependenceKind::Borrow;
+  case BridgedParsedLifetimeDependenceKindScope:
+    return swift::ParsedLifetimeDependenceKind::Scope;
   case BridgedParsedLifetimeDependenceKindInherit:
     return swift::ParsedLifetimeDependenceKind::Inherit;
-  case BridgedParsedLifetimeDependenceKindInout:
-    return swift::ParsedLifetimeDependenceKind::Inout;
   }
   llvm_unreachable("unhandled enum value");
 }

lib/AST/FeatureSet.cpp

@@ -270,18 +270,6 @@ static bool usesFeatureLifetimeDependence(Decl *decl) {
   return false;
 }
 
-static bool usesFeatureInoutLifetimeDependence(Decl *decl) {
-  for (auto attr : decl->getAttrs().getAttributes<LifetimeAttr>()) {
-    for (auto source : attr->getLifetimeEntry()->getSources()) {
-      if (source.getParsedLifetimeDependenceKind() ==
-          ParsedLifetimeDependenceKind::Inout) {
-        return true;
-      }
-    }
-  }
-  return false;
-}
-
 UNINTERESTING_FEATURE(DynamicActorIsolation)
 UNINTERESTING_FEATURE(NonfrozenEnumExhaustivity)
 UNINTERESTING_FEATURE(ClosureIsolation)