Merge pull request #41813 from tshortli/target-min-inlining-version-min

Frontend: Use Swift introduction as the default inlining availability floor instead of ABI stability

Author: tshortli

include/swift/Basic/Platform.h

@@ -55,8 +55,10 @@ namespace swift {
   bool triplesAreValidForZippering(const llvm::Triple &target,
                                    const llvm::Triple &targetVariant);
 
+  /// Returns the VersionTuple at which Swift first became available for the OS
+  /// represented by `triple`.
   const Optional<llvm::VersionTuple>
-  minimumABIStableOSVersionForTriple(const llvm::Triple &triple);
+  minimumAvailableOSVersionForTriple(const llvm::Triple &triple);
 
   /// Returns true if the given triple represents an OS that has all the
   /// "built-in" ABI-stable libraries (stdlib and _Concurrency)

lib/Basic/Platform.cpp

@@ -80,15 +80,20 @@ bool swift::triplesAreValidForZippering(const llvm::Triple &target,
 }
 
 const Optional<llvm::VersionTuple>
-swift::minimumABIStableOSVersionForTriple(const llvm::Triple &triple) {
+swift::minimumAvailableOSVersionForTriple(const llvm::Triple &triple) {
   if (triple.isMacOSX())
-    return llvm::VersionTuple(10, 14, 4);
+    return llvm::VersionTuple(10, 10, 0);
 
-  if (triple.isiOS() /* including tvOS */)
-    return llvm::VersionTuple(12, 2);
+  // Note: this must come before checking iOS since that returns true for
+  // both iOS and tvOS.
+  if (triple.isTvOS())
+    return llvm::VersionTuple(9, 0);
+
+  if (triple.isiOS())
+    return llvm::VersionTuple(8, 0);
 
   if (triple.isWatchOS())
-    return llvm::VersionTuple(5, 2);
+    return llvm::VersionTuple(2, 0);
 
   return None;
 }

lib/Frontend/CompilerInvocation.cpp

@@ -803,15 +803,12 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
   // First, set up default minimum inlining target versions.
   auto getDefaultMinimumInliningTargetVersion =
       [&](const llvm::Triple &triple) -> llvm::VersionTuple {
-#if SWIFT_DEFAULT_TARGET_MIN_INLINING_VERSION_TO_ABI
-    // In ABI-stable modules, default to the version where the target's ABI
-    // was first frozen; older versions will use that one's backwards
-    // compatibility libraries.
+#if SWIFT_DEFAULT_TARGET_MIN_INLINING_VERSION_TO_MIN
+    // In ABI-stable modules, default to the version when Swift first became
+    // available.
     if (FrontendOpts.EnableLibraryEvolution)
-      if (auto abiStability = minimumABIStableOSVersionForTriple(triple))
-        // FIXME: Should we raise it to the minimum supported OS version for
-        //        architectures which were born ABI-stable?
-        return *abiStability;
+      if (auto minTriple = minimumAvailableOSVersionForTriple(triple))
+        return minTriple;
 #endif
 
     // In ABI-unstable modules, we will never have to interoperate with
@@ -834,10 +831,10 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
     if (!A)
       return None;
 
+    if (StringRef(A->getValue()) == "min")
+      return minimumAvailableOSVersionForTriple(Opts.Target);
     if (StringRef(A->getValue()) == "target")
       return Opts.getMinPlatformVersion();
-    if (StringRef(A->getValue()) == "abi")
-      return minimumABIStableOSVersionForTriple(Opts.Target);
 
     if (auto vers = version::Version::parseVersionString(A->getValue(),
                                                          SourceLoc(), &Diags))

test/attr/attr_inlinable_available.swift

@@ -11,10 +11,9 @@
 
 // REQUIRES: swift_stable_abi
 
-
 // Primary execution of this test. Uses the default minimum inlining version,
-// which is the version when the ABI became stable.
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-library-evolution -target %target-next-stable-abi-triple -target-min-inlining-version abi
+// which is the version when Swift was introduced.
+// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-library-evolution -target %target-next-stable-abi-triple -target-min-inlining-version min
 
 
 // Check that these rules are only applied when requested and that at least some
@@ -34,12 +33,12 @@ public struct NoAvailable {
   @usableFromInline internal init() {}
 }
 
-@available(macOS 10.14.3, iOS 12.1, tvOS 12.1, watchOS 5.1, *)
+@available(macOS 10.9, iOS 7.0, tvOS 8.0, watchOS 1.0, *)
 public struct BeforeInliningTarget {
   @usableFromInline internal init() {}
 }
 
-@available(macOS 10.14.4, iOS 12.2, tvOS 12.2, watchOS 5.2, *)
+@available(macOS 10.10, iOS 8.0, tvOS 9.0, watchOS 2.0, *)
 public struct AtInliningTarget {
   @usableFromInline internal init() {}
 }
@@ -90,7 +89,7 @@ public func deployedUseNoAvailable( // expected-note 5 {{add @available attribut
   }
 }
 
-@available(macOS 10.14.3, iOS 12.1, tvOS 12.1, watchOS 5.1, *)
+@available(macOS 10.9, iOS 7.0, tvOS 8.0, watchOS 1.0, *)
 public func deployedUseBeforeInliningTarget(
   _: NoAvailable,
   _: BeforeInliningTarget,
@@ -115,7 +114,7 @@ public func deployedUseBeforeInliningTarget(
   }
 }
 
-@available(macOS 10.14.4, iOS 12.2, tvOS 12.2, watchOS 5.2, *)
+@available(macOS 10.10, iOS 8.0, tvOS 9.0, watchOS 2.0, *)
 public func deployedUseAtInliningTarget(
   _: NoAvailable,
   _: BeforeInliningTarget,
@@ -248,7 +247,7 @@ public func deployedUseAfterDeploymentTarget(
   }
 }
 
-@available(macOS 10.14.3, iOS 12.1, tvOS 12.1, watchOS 5.1, *)
+@available(macOS 10.9, iOS 7.0, tvOS 8.0, watchOS 1.0, *)
 @inlinable public func inlinedUseBeforeInliningTarget(
   _: NoAvailable,
   _: BeforeInliningTarget,
@@ -264,7 +263,7 @@ public func deployedUseAfterDeploymentTarget(
   _ = NoAvailable()
   _ = BeforeInliningTarget()
   _ = AtInliningTarget()
-  _ = BetweenTargets() // expected-error {{'BetweenTargets' is only available in}} {{18-25=10.14.5}} || {{31-35=12.3}} || {{42-46=12.3}} || {{56-59=5.3}}
+  _ = BetweenTargets() // expected-error {{'BetweenTargets' is only available in}} expected-note {{add 'if #available'}}
   _ = AtDeploymentTarget() // expected-error {{'AtDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
   _ = AfterDeploymentTarget() // expected-error {{'AfterDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
 
@@ -279,7 +278,7 @@ public func deployedUseAfterDeploymentTarget(
   }
 }
 
-@available(macOS 10.14.4, iOS 12.2, tvOS 12.2, watchOS 5.2, *)
+@available(macOS 10.10, iOS 8.0, tvOS 9.0, watchOS 2.0, *)
 @inlinable public func inlinedUseAtInliningTarget(
   _: NoAvailable,
   _: BeforeInliningTarget,
@@ -295,7 +294,7 @@ public func deployedUseAfterDeploymentTarget(
   _ = NoAvailable()
   _ = BeforeInliningTarget()
   _ = AtInliningTarget()
-  _ = BetweenTargets() // expected-error {{'BetweenTargets' is only available in}} {{18-25=10.14.5}} || {{31-35=12.3}} || {{42-46=12.3}} || {{56-59=5.3}}
+  _ = BetweenTargets() // expected-error {{'BetweenTargets' is only available in}} expected-note {{add 'if #available'}}
   _ = AtDeploymentTarget() // expected-error {{'AtDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
   _ = AfterDeploymentTarget() // expected-error {{'AfterDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
 
@@ -426,6 +425,40 @@ internal func fn() {
   }
 }
 
+// @_backDeploy acts like @inlinable.
+
+@available(macOS 10.10, iOS 8.0, tvOS 9.0, watchOS 2.0, *)
+@_backDeploy(macOS 999.0, iOS 999.0, tvOS 999.0, watchOS 999.0)
+public func backDeployedToInliningTarget(
+  _: NoAvailable,
+  _: BeforeInliningTarget,
+  _: AtInliningTarget,
+  _: BetweenTargets, // expected-error {{'BetweenTargets' is only available in}}
+  _: AtDeploymentTarget, // expected-error {{'AtDeploymentTarget' is only available in}}
+  _: AfterDeploymentTarget // expected-error {{'AfterDeploymentTarget' is only available in}}
+) {
+  defer {
+    _ = AtDeploymentTarget() // expected-error {{'AtDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
+    _ = AfterDeploymentTarget() // expected-error {{'AfterDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
+  }
+  _ = NoAvailable()
+  _ = BeforeInliningTarget()
+  _ = AtInliningTarget()
+  _ = BetweenTargets() // expected-error {{'BetweenTargets' is only available in}} expected-note {{add 'if #available'}}
+  _ = AtDeploymentTarget() // expected-error {{'AtDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
+  _ = AfterDeploymentTarget() // expected-error {{'AfterDeploymentTarget' is only available in}} expected-note {{add 'if #available'}}
+
+  if #available(macOS 10.14.5, iOS 12.3, tvOS 12.3, watchOS 5.3, *) {
+    _ = BetweenTargets()
+  }
+  if #available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *) {
+    _ = AtDeploymentTarget()
+  }
+  if #available(macOS 11, iOS 14, tvOS 14, watchOS 7, *) {
+    _ = AfterDeploymentTarget()
+  }
+}
+
 // Default arguments act like @inlinable.
 
 public func defaultArgsUseNoAvailable( // expected-note 3 {{add @available attribute}}