AST: @inline(__always) no longer implies @inlinable

Fixes <rdar://problem/44657000>.

Author: slavapestov

include/swift/AST/DiagnosticsSema.def

@@ -4097,7 +4097,6 @@ ERROR(usable_from_inline_attr_in_protocol,none,
 
 #define FRAGILE_FUNC_KIND \
   "%select{a '@_transparent' function|" \
-  "an '@inline(__always)' function|" \
   "an '@inlinable' function|" \
   "a default argument value|" \
   "a property initializer in a '@_fixed_layout' type}"
@@ -4126,7 +4125,7 @@ NOTE(resilience_decl_declared_here,
 
 ERROR(class_designated_init_inlinable_resilient,none,
       "initializer for class %0 is "
-      "'%select{@_transparent|@inline(__always)|@inlinable|%error}1' and must "
+      "'%select{@_transparent|@inlinable|%error}1' and must "
       "delegate to another initializer", (Type, unsigned))
 
 ERROR(attribute_invalid_on_stored_property,

lib/AST/DeclContext.cpp

@@ -323,18 +323,13 @@ ResilienceExpansion DeclContext::getResilienceExpansion() const {
       if (!funcAccess.isPublic())
         break;
 
-      // Bodies of public transparent and always-inline functions are
-      // serialized, so use conservative access patterns.
+      // If the function is public, @_transparent implies @inlinable.
       if (AFD->isTransparent())
         return ResilienceExpansion::Minimal;
 
       if (AFD->getAttrs().hasAttribute<InlinableAttr>())
         return ResilienceExpansion::Minimal;
 
-      if (auto attr = AFD->getAttrs().getAttribute<InlineAttr>())
-        if (attr->getKind() == InlineKind::Always)
-          return ResilienceExpansion::Minimal;
-
       // If a property or subscript is @inlinable, the accessors are
       // @inlinable also.
       if (auto accessor = dyn_cast<AccessorDecl>(AFD))

lib/Sema/ResilienceDiagnostics.cpp

@@ -58,11 +58,6 @@ TypeChecker::getFragileFunctionKind(const DeclContext *DC) {
         return std::make_pair(FragileFunctionKind::Inlinable,
                               /*treatUsableFromInlineAsPublic=*/true);
 
-      if (auto attr = AFD->getAttrs().getAttribute<InlineAttr>())
-        if (attr->getKind() == InlineKind::Always)
-          return std::make_pair(FragileFunctionKind::InlineAlways,
-                                /*treatUsableFromInlineAsPublic=*/true);
-
       // If a property or subscript is @inlinable, the accessors are
       // @inlinable also.
       if (auto accessor = dyn_cast<AccessorDecl>(AFD))

lib/Sema/TypeChecker.h

@@ -1955,7 +1955,6 @@ class TypeChecker final : public LazyResolver {
   /// Used in diagnostic %selects.
   enum class FragileFunctionKind : unsigned {
     Transparent,
-    InlineAlways,
     Inlinable,
     DefaultArgument,
     PropertyInitializer

test/ParseableInterface/inlinable-function.swift

@@ -199,14 +199,6 @@ public struct Foo: Hashable {
     inlinableProperty = 4
   }
 
-  // CHECK: @inline(__always) [[ATTRS]] func inlineAlwaysMethod() {
-  // CHECK-NEXT: inlinableProperty = 4
-  // CHECK-NEXT: }
-  @inline(__always)
-  mutating public func inlineAlwaysMethod() {
-    inlinableProperty = 4
-  }
-
   // CHECK: public func nonInlinableMethod(){{$}}
   // CHECK-NOT: print("Not inlinable")
   public func nonInlinableMethod() {

test/SILGen/functions.swift

@@ -426,7 +426,7 @@ func noinline_callee() {}
 @inline(__always)
 func always_inline_callee() {}
 
-// CHECK-LABEL: sil [serialized] [always_inline] @$s9functions27public_always_inline_calleeyyF : $@convention(thin) () -> ()
+// CHECK-LABEL: sil [always_inline] @$s9functions27public_always_inline_calleeyyF : $@convention(thin) () -> ()
 @inline(__always)
 public func public_always_inline_callee() {}
 

test/SILGen/nested-function-fragility.swift

@@ -43,7 +43,7 @@ internal func bar() {
 public func publicFunc() {}
 
 // CHECK-LABEL: sil [serialized] [always_inline] @$s4main3basyyF
-@inline(__always)
+@inlinable @inline(__always)
 public func bas() {
   // CHECK-LABEL: sil shared [serialized] [always_inline] @$s4main3basyyF3zimL_yyF
   @inline(__always)

test/SILGen/struct_resilience.swift

@@ -195,8 +195,8 @@ public func functionWithMyResilientTypes(_ s: MySize, f: (MySize) -> MySize) ->
   return s.w
 }
 
-// CHECK-LABEL: sil [serialized] [always_inline] @$s17struct_resilience26publicInlineAlwaysFunctionySiAA6MySizeVF : $@convention(thin) (@in_guaranteed MySize) -> Int
-@inline(__always) public func publicInlineAlwaysFunction(_ s: MySize) -> Int {
+// CHECK-LABEL: sil [serialized] @$s17struct_resilience23publicInlinableFunctionySiAA6MySizeVF : $@convention(thin) (@in_guaranteed MySize) -> Int
+@inlinable public func publicInlinableFunction(_ s: MySize) -> Int {
 
   // Since the body of a public transparent function might be inlined into
   // other resilience domains, we have to use accessors

test/Serialization/Inputs/def_always_inline.swift

@@ -1,4 +1,4 @@
-@inline(__always) public func testAlwaysInline(x: Bool) -> Bool {
+@inline(__always) @inlinable public func testAlwaysInline(x: Bool) -> Bool {
   return x
 }
 
@@ -7,7 +7,7 @@ public struct AlwaysInlineInitStruct {
   @usableFromInline
   var x: Bool
 
-  @inline(__always)
+  @inline(__always) @inlinable
   public init(x x2: Bool) {
     self.x = x2
   }

test/attr/attr_inlinable.swift

@@ -20,7 +20,7 @@ public func publicFunction() {}
 private struct PrivateStruct {}
 // expected-note@-1 3{{struct 'PrivateStruct' is not '@usableFromInline' or public}}
 struct InternalStruct {}
-// expected-note@-1 4{{struct 'InternalStruct' is not '@usableFromInline' or public}}
+// expected-note@-1 3{{struct 'InternalStruct' is not '@usableFromInline' or public}}
 @usableFromInline struct VersionedStruct {
   @usableFromInline init() {}
 }
@@ -79,18 +79,6 @@ public struct Struct {
     // expected-error@-1 {{struct 'PrivateStruct' is private and cannot be referenced from an '@inlinable' function}}
   }
 
-  @inline(__always)
-  public func publicInlineAlwaysMethod(x: Any) {
-    struct Nested {}
-    // expected-error@-1 {{type 'Nested' cannot be nested inside an '@inline(__always)' function}}
-
-    switch x {
-      case is InternalStruct:
-      // expected-error@-1 {{struct 'InternalStruct' is internal and cannot be referenced from an '@inline(__always)' function}}
-        _ = ()
-    }
-  }
-
   private func privateMethod() {}
   // expected-note@-1 {{instance method 'privateMethod()' is not '@usableFromInline' or public}}
 
@@ -109,13 +97,6 @@ public struct Struct {
     // expected-error@-1 {{type 'Nested' cannot be nested inside an '@inlinable' function}}
   }
 
-  @inline(__always)
-  @usableFromInline
-  func versionedInlineAlwaysMethod() {
-    struct Nested {}
-    // expected-error@-1 {{type 'Nested' cannot be nested inside an '@inline(__always)' function}}
-  }
-
   @_transparent
   func internalTransparentMethod() {
     struct Nested {}