Finish implementing @abi (SE-0476)

include/swift/AST/DeclAttr.def

@@ -861,7 +861,6 @@ DECL_ATTR(abi, ABI,
   OnConstructor | OnFunc | OnSubscript | OnVar,
   LongAttribute | ABIStableToAdd | ABIStableToRemove | APIStableToAdd | APIStableToRemove | ForbiddenInABIAttr,
   165)
-DECL_ATTR_FEATURE_REQUIREMENT(ABI, ABIAttribute)
 
 // Unused '166': Used to be `@execution(caller | concurrent)` replaced with `@concurrent` and `nonisolated(nonsending)`
 

include/swift/AST/DiagnosticsSema.def

@@ -8468,14 +8468,10 @@ ERROR(attr_abi_mismatched_async,none,
       "cannot give %0 the ABI of %select{a non-async|an async}1 %kindonly0",
       (Decl *, /*abiIsAsync=*/bool))
 
-ERROR(attr_abi_mismatched_pbd_size,none,
-      "cannot give pattern binding the ABI of a binding with "
-      "%select{more|fewer}0 patterns",
-      (/*abiHasExtra=*/bool))
-
-ERROR(attr_abi_mismatched_var,none,
-      "no match for %select{%kind0 in the ABI|ABI %kind0}1",
-      (Decl *, /*isABI=*/bool))
+ERROR(attr_abi_multiple_vars,none,
+      "'abi' attribute can only be applied to a single %0; declare each "
+      "%0 separately",
+      (DescriptiveDeclKind))
 
 ERROR(attr_abi_incompatible_with_silgen_name,none,
       "cannot use '@_silgen_name' and '@abi' on the same %kindonly0 because "

include/swift/Basic/Features.def

@@ -257,6 +257,7 @@ LANGUAGE_FEATURE(SendableCompletionHandlers, 463, "Objective-C completion handle
 LANGUAGE_FEATURE(AsyncExecutionBehaviorAttributes, 0, "@concurrent and nonisolated(nonsending)")
 LANGUAGE_FEATURE(IsolatedConformances, 407, "Global-actor isolated conformances")
 LANGUAGE_FEATURE(ValueGenericsNameLookup, 452, "Value generics appearing as static members for namelookup")
+SUPPRESSIBLE_LANGUAGE_FEATURE(ABIAttributeSE0479, 479, "@abi attribute on functions, initializers, properties, and subscripts")
 
 // Swift 6
 UPCOMING_FEATURE(ConciseMagicFile, 274, 6)
@@ -487,9 +488,6 @@ EXPERIMENTAL_FEATURE(CoroutineAccessorsUnwindOnCallerError, false)
 EXPERIMENTAL_FEATURE(AddressableParameters, true)
 SUPPRESSIBLE_EXPERIMENTAL_FEATURE(AddressableTypes, true)
 
-/// Allow the @abi attribute.
-SUPPRESSIBLE_EXPERIMENTAL_FEATURE(ABIAttribute, true)
-
 /// Allow custom availability domains to be defined and referenced.
 EXPERIMENTAL_FEATURE(CustomAvailability, true)
 

lib/AST/ASTPrinter.cpp

@@ -3289,8 +3289,8 @@ suppressingFeatureCoroutineAccessors(PrintOptions &options,
 }
 
 static void
-suppressingFeatureABIAttribute(PrintOptions &options,
-                               llvm::function_ref<void()> action) {
+suppressingFeatureABIAttributeSE0479(PrintOptions &options,
+                                     llvm::function_ref<void()> action) {
   llvm::SaveAndRestore<bool> scope1(options.PrintSyntheticSILGenName, true);
   ExcludeAttrRAII scope2(options.ExcludeAttrList, DeclAttrKind::ABI);
   action();

lib/AST/FeatureSet.cpp

@@ -388,7 +388,7 @@ static ABIAttr *getABIAttr(Decl *decl) {
   return decl->getAttrs().getAttribute<ABIAttr>();
 }
 
-static bool usesFeatureABIAttribute(Decl *decl) {
+static bool usesFeatureABIAttributeSE0479(Decl *decl) {
   return getABIAttr(decl) != nullptr;
 }
 

lib/ASTGen/Sources/ASTGen/SourceFile.swift

@@ -75,7 +75,6 @@ extension Parser.ExperimentalFeatures {
     mapFeature(.NonescapableTypes, to: .nonescapableTypes)
     mapFeature(.TrailingComma, to: .trailingComma)
     mapFeature(.CoroutineAccessors, to: .coroutineAccessors)
-    mapFeature(.ABIAttribute, to: .abiAttribute)
     mapFeature(.OldOwnershipOperatorSpellings, to: .oldOwnershipOperatorSpellings)
     mapFeature(.KeyPathWithMethodMembers, to: .keypathWithMethodMembers)
     mapFeature(.InlineArrayTypeSugar, to: .inlineArrayTypeSugar)

lib/Sema/TypeCheckAttrABI.cpp

@@ -1102,60 +1102,29 @@ class ABIDeclChecker : public ASTComparisonVisitor<ABIDeclChecker> {
 };
 
 void checkABIAttrPBD(PatternBindingDecl *APBD, VarDecl *VD) {
-  auto &diags = VD->getASTContext().Diags;
   auto PBD = VD->getParentPatternBinding();
 
-  // To make sure we only diagnose this stuff once, check that VD is the first
-  // anchoring variable in the PBD.
-  bool isFirstAnchor = false;
+  Decl *anchorVD = nullptr;
   for (auto i : range(PBD->getNumPatternEntries())) {
-    auto anchorVD = PBD->getAnchoringVarDecl(i);
-    if (anchorVD) {
-      isFirstAnchor = (anchorVD == VD);
+    anchorVD = PBD->getAnchoringVarDecl(i);
+    if (anchorVD)
       break;
-    }
   }
 
-  if (!isFirstAnchor)
+  // To make sure we only diagnose this stuff once, check that VD is the
+  // first anchoring variable in the PBD.
+  if (anchorVD != VD)
     return;
 
-  // Check that the PBDs have the same number of patterns.
-  if (PBD->getNumPatternEntries() < APBD->getNumPatternEntries()) {
-    diags.diagnose(APBD->getPattern(PBD->getNumPatternEntries())->getLoc(),
-                   diag::attr_abi_mismatched_pbd_size, /*abiHasExtra=*/false);
-    return;
-  }
-  if (PBD->getNumPatternEntries() > APBD->getNumPatternEntries()) {
-    diags.diagnose(PBD->getPattern(APBD->getNumPatternEntries())->getLoc(),
-                   diag::attr_abi_mismatched_pbd_size, /*abiHasExtra=*/true);
+  // In the final approved feature, we only permit single-variable patterns.
+  // (However, the rest of the compiler tolerates them.)
+  if (!PBD->getSingleVar() || !APBD->getSingleVar()) {
+    PBD->diagnose(diag::attr_abi_multiple_vars,
+                  anchorVD ? anchorVD->getDescriptiveKind()
+                           : PBD->getDescriptiveKind());
     return;
   }
 
-  // Check that each pattern has the same number of variables.
-  bool didDiagnose = false;
-  for (auto i : range(PBD->getNumPatternEntries())) {
-    SmallVector<VarDecl *, 8> VDs;
-    SmallVector<VarDecl *, 8> AVDs;
-
-    PBD->getPattern(i)->collectVariables(VDs);
-    APBD->getPattern(i)->collectVariables(AVDs);
-
-    if (VDs.size() < AVDs.size()) {
-      for (auto AVD : drop_begin(AVDs, VDs.size())) {
-        AVD->diagnose(diag::attr_abi_mismatched_var, AVD, /*isABI=*/true);
-        didDiagnose = true;
-      }
-    }
-    else if (VDs.size() > AVDs.size()) {
-      for (auto VD : drop_begin(VDs, AVDs.size())) {
-        VD->diagnose(diag::attr_abi_mismatched_var, VD, /*isABI=*/false);
-        didDiagnose = true;
-      }
-    }
-  }
-  if (didDiagnose)
-    return;
-
   // Check the ABI PBD--this is what checks the underlying vars.
   TypeChecker::typeCheckDecl(APBD);
 }

test/ASTGen/attrs.swift

@@ -1,7 +1,6 @@
 // RUN: %empty-directory(%t)
 
 // RUN: %target-swift-frontend-dump-parse \
-// RUN:   -enable-experimental-feature ABIAttribute \
 // RUN:   -enable-experimental-feature Extern \
 // RUN:   -enable-experimental-feature LifetimeDependence \
 // RUN:   -enable-experimental-feature RawLayout \
@@ -12,7 +11,6 @@
 // RUN:   | %sanitize-address > %t/astgen.ast
 
 // RUN: %target-swift-frontend-dump-parse \
-// RUN:   -enable-experimental-feature ABIAttribute \
 // RUN:   -enable-experimental-feature Extern \
 // RUN:   -enable-experimental-feature LifetimeDependence \
 // RUN:   -enable-experimental-feature RawLayout \
@@ -26,7 +24,6 @@
 // RUN: %target-typecheck-verify-swift \
 // RUN:   -module-abi-name ASTGen \
 // RUN:   -enable-experimental-feature ParserASTGen \
-// RUN:   -enable-experimental-feature ABIAttribute \
 // RUN:   -enable-experimental-feature Extern \
 // RUN:   -enable-experimental-feature LifetimeDependence \
 // RUN:   -enable-experimental-feature RawLayout \
@@ -38,7 +35,6 @@
 // REQUIRES: executable_test
 // REQUIRES: swift_swift_parser
 // REQUIRES: swift_feature_ParserASTGen
-// REQUIRES: swift_feature_ABIAttribute
 // REQUIRES: swift_feature_Extern
 // REQUIRES: swift_feature_LifetimeDependence
 // REQUIRES: swift_feature_RawLayout

test/IDE/complete_decl_attribute.swift

@@ -19,6 +19,11 @@
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=KEYWORD_INDEPENDENT_2 | %FileCheck %s -check-prefix=KEYWORD_LAST
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=KEYWORD_LAST | %FileCheck %s -check-prefix=KEYWORD_LAST
 
+// NOTE: If you want to test code completion for an experimental feature, please
+// put your tests in complete_decl_attribute_feature_requirement.swift, not
+// here. That file has the infrastructure to test that completions are not
+// offered when the feature is disabled.
+
 struct MyStruct {}
 
 @propertyWrapper
@@ -112,6 +117,7 @@ actor MyGenericGlobalActor<T> {
 // KEYWORD2-NEXT:             Keyword/None:                       preconcurrency[#Func Attribute#]; name=preconcurrency
 // KEYWORD2-NEXT:             Keyword/None:                       backDeployed[#Func Attribute#]; name=backDeployed
 // KEYWORD2-NEXT:             Keyword/None:                       lifetime[#Func Attribute#]; name=lifetime
+// KEYWORD2-NEXT:             Keyword/None:                       abi[#Func Attribute#]; name=abi{{$}}
 // KEYWORD2-NEXT:             Keyword/None:                       concurrent[#Func Attribute#]; name=concurrent
 // KEYWORD2-NOT:              Keyword
 // KEYWORD2-DAG:              Decl[Struct]/CurrModule:            MyStruct[#MyStruct#]; name=MyStruct
@@ -169,6 +175,7 @@ actor MyGenericGlobalActor<T> {
 // KEYWORD5-NEXT:             Keyword/None:                       preconcurrency[#Struct Attribute#]; name=preconcurrency
 
 @#^ON_GLOBALVAR^# var globalVar
+// ON_GLOBALVAR-DAG: Keyword/None:                       abi[#Var Attribute#]; name=abi
 // ON_GLOBALVAR-DAG: Keyword/None:                       available[#Var Attribute#]; name=available
 // ON_GLOBALVAR-DAG: Keyword/None:                       objc[#Var Attribute#]; name=objc
 // ON_GLOBALVAR-DAG: Keyword/None:                       NSCopying[#Var Attribute#]; name=NSCopying
@@ -197,6 +204,7 @@ actor MyGenericGlobalActor<T> {
 
 struct _S {
   @#^ON_INIT^# init()
+// ON_INIT-DAG: Keyword/None:                       abi[#Constructor Attribute#]; name=abi
 // ON_INIT-DAG: Keyword/None:                       available[#Constructor Attribute#]; name=available
 // ON_INIT-DAG: Keyword/None:                       objc[#Constructor Attribute#]; name=objc
 // ON_INIT-DAG: Keyword/None:                       inline[#Constructor Attribute#]; name=inline
@@ -207,6 +215,7 @@ struct _S {
 // ON_INIT-DAG: Keyword/None:                       preconcurrency[#Constructor Attribute#]; name=preconcurrency
 
   @#^ON_PROPERTY^# var foo
+// ON_PROPERTY-DAG: Keyword/None:                       abi[#Var Attribute#]; name=abi
 // ON_PROPERTY-DAG: Keyword/None:                       available[#Var Attribute#]; name=available
 // ON_PROPERTY-DAG: Keyword/None:                       objc[#Var Attribute#]; name=objc
 // ON_PROPERTY-DAG: Keyword/None:                       NSCopying[#Var Attribute#]; name=NSCopying
@@ -234,8 +243,12 @@ struct _S {
 // ON_PROPERTY-DAG: Decl[Actor]/CurrModule/TypeRelation[Convertible]: MyGenericGlobalActor[#Global Actor#]; name=MyGenericGlobalActor
 // ON_PROPERTY-NOT: Decl[PrecedenceGroup]
 
+  @#^ON_SUBSCR^# subscript
+// ON_SUBSCR-DAG:  Keyword/None:                        abi[#Declaration Attribute#]; name=abi
+
   @#^ON_METHOD^# private
   func foo()
+// ON_METHOD-DAG: Keyword/None:                       abi[#Func Attribute#]; name=abi
 // ON_METHOD-DAG: Keyword/None:                       available[#Func Attribute#]; name=available
 // ON_METHOD-DAG: Keyword/None:                       objc[#Func Attribute#]; name=objc
 // ON_METHOD-DAG: Keyword/None:                       IBAction[#Func Attribute#]; name=IBAction
@@ -293,6 +306,7 @@ struct _S {
 
 
   @#^ON_MEMBER_LAST^#
+// ON_MEMBER_LAST-DAG: Keyword/None:                       abi[#Declaration Attribute#]; name=abi
 // ON_MEMBER_LAST-DAG: Keyword/None:                       available[#Declaration Attribute#]; name=available
 // ON_MEMBER_LAST-DAG: Keyword/None:                       objc[#Declaration Attribute#]; name=objc
 // ON_MEMBER_LAST-DAG: Keyword/None:                       dynamicCallable[#Declaration Attribute#]; name=dynamicCallable
@@ -347,6 +361,8 @@ func takeClosure(_: () -> Void) {
     print("x")
   }
 }
+// FIXME: Not valid in this position (but CompletionLookup can't tell that)
+// IN_CLOSURE-DAG:  Keyword/None:              abi[#Declaration Attribute#]; name=abi
 // FIXME: We should mark MyPropertyWrapper and MyResultBuilder as Unrelated
 // IN_CLOSURE-DAG: Decl[Struct]/CurrModule: MyStruct[#MyStruct#]; name=MyStruct
 // IN_CLOSURE-DAG: Decl[Struct]/CurrModule/TypeRelation[Convertible]: MyPropertyWrapper[#Property Wrapper#]; name=MyPropertyWrapper
@@ -365,6 +381,7 @@ func dummy2() {}
 
 @#^KEYWORD_LAST^#
 
+// KEYWORD_LAST-DAG: Keyword/None:                       abi[#Declaration Attribute#]; name=abi
 // KEYWORD_LAST-DAG: Keyword/None:                       available[#Declaration Attribute#]; name=available{{$}}
 // KEYWORD_LAST-DAG: Keyword/None:                       freestanding[#Declaration Attribute#]; name=freestanding{{$}}
 // KEYWORD_LAST-DAG: Keyword/None:                       objc[#Declaration Attribute#]; name=objc{{$}}

test/IDE/complete_decl_attribute_feature_requirement.swift

@@ -3,6 +3,11 @@
 // it's enabled. When a feature becomes non-experimental, move its test cases
 // into the normal complete_decl_attribute.swift test file.
 
+// NOTE: There are currently no experimental features that need code completion
+// testing, but this test file is being left in place for when it's needed
+// again. At that time, please remove the ABIAttribute tests.
+// REQUIRES: new_use_case
+
 // REQUIRES: asserts
 
 // RUN: %batch-code-completion -filecheck-additional-suffix _DISABLED

test/IRGen/asmname.swift

@@ -1,9 +1,8 @@
-// RUN: %target-swift-frontend -enable-experimental-feature ABIAttribute %s -emit-ir > %t.ir
+// RUN: %target-swift-frontend %s -emit-ir > %t.ir
 // RUN: %FileCheck --input-file %t.ir %s
 // RUN: %FileCheck --check-prefix NEGATIVE --input-file %t.ir %s
 
 // REQUIRES: CPU=i386 || CPU=x86_64 || CPU=arm64
-// REQUIRES: swift_feature_ABIAttribute
 
 // Non-Swift _silgen_name definitions
 

test/Macros/macro_expand.swift

@@ -719,6 +719,29 @@ func testPropertyWrapperMacro() {
   #hasPropertyWrapperParam($x: .init(wrappedValue: 0))
 }
 
+#if swift(>=1.0) && TEST_DIAGNOSTICS
+// Test that macros can't be used in @abi
+
+struct ABIAttrWithFreestandingMacro1 {
+  // expected-error@+1 {{cannot use pound literal in '@abi'}}
+  @abi(#varValue)
+  #varValue
+  // expected-note@-1 {{in expansion of macro 'varValue' here}}
+}
+
+struct ABIAttrWithFreestandingMacro2 {
+  // expected-error@+1 {{cannot use pound literal in '@abi'}}
+  @abi(#varValue)
+  var value: Int { 0 }
+}
+
+struct ABIAttrWithFreestandingMacro3 {
+  @abi(var value: Int)
+  #varValue
+}
+
+#endif
+
 #if TEST_DIAGNOSTICS
 @freestanding(expression)
 macro missingMacro() = #externalMacro(module: "MacroDefinition", type: "BluhBlah")

test/Macros/macro_expand_peers.swift

@@ -309,3 +309,26 @@ func closuresInPeerMacroCrash() {}
 @trait(Trait {})
 @trait(Trait {})
 var closuresInPeerMacroOnVariableCrash: Int = 0
+
+// Test that macros can't be used in @abi
+
+#if swift(>=5.3) && TEST_DIAGNOSTICS
+struct ABIAttrWithAttachedMacro {
+  // expected-error@+1 {{macro 'addCompletionHandler()' cannot be expanded in '@abi' attribute}}
+  @abi(@addCompletionHandler func fn1() async)
+  @addCompletionHandler func fn1() async {}
+  // From diagnostics in the expansion:
+  // expected-note@-2 3{{in expansion of macro 'addCompletionHandler' on instance method 'fn1()' here}}
+  // expected-note@-4 {{'fn1()' previously declared here}}
+
+  // expected-error@+1 {{macro 'addCompletionHandler()' cannot be expanded in '@abi' attribute}}
+  @abi(@addCompletionHandler func fn2() async)
+  func fn2() async {}
+
+  @abi(func fn3() async)
+  @addCompletionHandler func fn3() async {}
+  // From diagnostics in the expansion:
+  // expected-note@-2 2{{in expansion of macro 'addCompletionHandler' on instance method 'fn3()' here}}
+  // expected-note@-4 {{'fn3()' previously declared here}}
+}
+#endif