Merge pull request #66117 from DougGregor/se-0397-enable-by-default-5.9

DougGregor · web-flow · commit a63c8d550e95 · 2023-05-25T10:39:21.000-07:00
[SE-0397] Enable freestanding declaration macros by default.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,6 +4,69 @@ _**Note:** This is in reverse chronological order, so newer entries are added to
 
 ## Swift 5.9
 
+* [SE-0382][], [SE-0389][], [SE-0394][], [SE-0397][]:
+
+  Swift 5.9 includes a new macro system that can be used to eliminate boilerplate and provide new forms of expressive APIs. Macros are declared with the new `macro` introducer:
+
+  ```swift
+  @freestanding(expression)
+  macro assert(_ condition: Bool) = #externalMacro(module: "PowerAssertMacros", type: "AssertMacro")
+  ```
+
+  Macros have parameter and result types, like functions, but are defined as separate programs that operate on syntax trees (using [swift-syntax][]) and produce new syntax trees that are incorporated into the program. Freestanding macros, indicated with the `@freestanding` attribute, are expanded in source code with a leading `#`:
+
+  ```swift
+  #assert(x + y == z) // expands to check the result of x + y == z and report failure if it's false
+  ```
+
+  Macros can also be marked as `@attached`, in which case they will be meaning that they will be expanded using custom attribute syntax. For example:
+
+  ```swift
+  @attached(peer, names: overloaded)
+  macro AddCompletionHandler() = #externalMacro(
+    module: "ConcurrencyHelperMacros",
+    type: "AddCompletionHandlerMacro"
+  )
+  
+  @AddCompletionHandler
+  func fetchAvatar(from url: URL) throws -> Image { ... }
+  
+  // expands to...
+  func fetchAvatar(from url: URL, completionHandler: @escaping (Result<Image, Error>) -> Void) {
+    Task.detached {
+      do {
+        let result = try await fetchAvatar(from: url)
+        completionHandler(.success(result))
+      } catch {
+        completionHandler(.failure(error))
+      }
+    }
+  }
+  ```
+
+  Macros are implemented in separate programs, which are executed by the Swift compiler. The Swift Package Manager's manifest provides a new `macro` target type to describe macros:
+
+  ```swift
+  import PackageDescription
+  import CompilerPluginSupport
+  
+  let package = Package(
+      name: "ConcurrencyHelpers",
+      dependencies: [
+          .package(url: "https://github.com/apple/swift-syntax", from: "509.0.0"),
+      ],
+      targets: [
+          .macro(name: "ConcurrencyHelperMacros",
+                 dependencies: [
+                     .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
+                     .product(name: "SwiftCompilerPlugin", package: "swift-syntax")
+                 ]),
+          .target(name: "ConcurrencyHelpers", dependencies: ["ConcurrencyHelperMacros"]),
+          .testTarget(name: "ConcurrencyHelperMacroTests", dependencies: ["ConcurrencyHelperMacros"]),
+      ]
+  )
+  ```
+
 * [SE-0380][]:
 
   `if` and `switch` statements may now be used as expressions to:
@@ -9763,7 +9826,10 @@ using the `.dynamicType` member to retrieve the type of an expression should mig
 [SE-0376]: <https://github.com/apple/swift-evolution/blob/main/proposals/0376-function-back-deployment.md>
 [SE-0377]: <https://github.com/apple/swift-evolution/blob/main/proposals/0377-parameter-ownership-modifiers.md>
 [SE-0380]: <https://github.com/apple/swift-evolution/blob/main/proposals/0380-if-switch-expressions.md>
-
+[SE-0382]: https://github.com/apple/swift-evolution/blob/main/proposals/0382-expression-macros.md
+[SE-0389]: https://github.com/apple/swift-evolution/blob/main/proposals/0389-attached-macros.md
+[SE-0394]: https://github.com/apple/swift-evolution/blob/main/proposals/0394-swiftpm-expression-macros.md
+[SE-0397]: https://github.com/apple/swift-evolution/blob/main/proposals/0397-freestanding-declaration-macros.md
 [#64927]: <https://github.com/apple/swift/issues/64927>
 [#42697]: <https://github.com/apple/swift/issues/42697>
 [#42728]: <https://github.com/apple/swift/issues/42728>
@@ -9805,3 +9871,4 @@ using the `.dynamicType` member to retrieve the type of an expression should mig
 [#57081]: <https://github.com/apple/swift/issues/57081>
 [#57225]: <https://github.com/apple/swift/issues/57225>
 [#56139]: <https://github.com/apple/swift/issues/56139>
+[swift-syntax]: https://github.com/apple/swift-syntax
diff --git a/include/swift/Basic/Features.def b/include/swift/Basic/Features.def
@@ -106,6 +106,7 @@ LANGUAGE_FEATURE(
 LANGUAGE_FEATURE(AttachedMacros, 389, "Attached macros", hasSwiftSwiftParser)
 LANGUAGE_FEATURE(MoveOnly, 390, "noncopyable types", true)
 LANGUAGE_FEATURE(ParameterPacks, 393, "Value and type parameter packs", true)
+LANGUAGE_FEATURE(FreestandingMacros, 397, "freestanding declaration macros", true)
 
 UPCOMING_FEATURE(ConciseMagicFile, 274, 6)
 UPCOMING_FEATURE(ForwardTrailingClosures, 286, 6)
@@ -117,7 +118,6 @@ EXPERIMENTAL_FEATURE(StaticAssert, false)
 EXPERIMENTAL_FEATURE(VariadicGenerics, false)
 EXPERIMENTAL_FEATURE(NamedOpaqueTypes, false)
 EXPERIMENTAL_FEATURE(FlowSensitiveConcurrencyCaptures, false)
-EXPERIMENTAL_FEATURE(FreestandingMacros, true)
 EXPERIMENTAL_FEATURE(CodeItemMacros, true)
 EXPERIMENTAL_FEATURE(TupleConformances, false)
 
diff --git a/lib/Sema/TypeCheckMacros.cpp b/lib/Sema/TypeCheckMacros.cpp
@@ -963,11 +963,6 @@ swift::expandFreestandingMacro(MacroExpansionDecl *med) {
     // macros need the `FreestandingMacros` feature flag, and code item macros
     // need both `FreestandingMacros` and `CodeItemMacros`.
     if (!macroRoles.contains(MacroRole::Expression)) {
-      if (!ctx.LangOpts.hasFeature(Feature::FreestandingMacros)) {
-        med->diagnose(diag::macro_experimental, "freestanding",
-                      "FreestandingMacros");
-        return None;
-      }
       if (!macroRoles.contains(MacroRole::Declaration) &&
           !ctx.LangOpts.hasFeature(Feature::CodeItemMacros)) {
         med->diagnose(diag::macro_experimental, "code item", "CodeItemMacros");
diff --git a/test/Macros/macro_expand.swift b/test/Macros/macro_expand.swift
@@ -4,32 +4,32 @@
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath -swift-version 5
 
 // Diagnostics testing
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS
 
 // Diagnostics testing by importing macros from a module
 // RUN: %target-swift-frontend -swift-version 5 -emit-module -o %t/freestanding_macro_library.swiftmodule %S/Inputs/freestanding_macro_library.swift -module-name freestanding_macro_library -load-plugin-library %t/%target-library-name(MacroDefinition)
 // RUN: %target-swift-frontend -swift-version 5 -emit-module -o %t/freestanding_macro_library_2.swiftmodule %S/Inputs/freestanding_macro_library_2.swift -module-name freestanding_macro_library_2 -load-plugin-library %t/%target-library-name(MacroDefinition) -I %t
 
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -I %t -DIMPORT_MACRO_LIBRARY
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -I %t -DIMPORT_MACRO_LIBRARY
 
-// RUN: not %target-swift-frontend -swift-version 5 -typecheck -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -serialize-diagnostics-path %t/macro_expand.dia %s -emit-macro-expansion-files no-diagnostics > %t/macro-printing.txt
+// RUN: not %target-swift-frontend -swift-version 5 -typecheck -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -serialize-diagnostics-path %t/macro_expand.dia %s -emit-macro-expansion-files no-diagnostics > %t/macro-printing.txt
 // RUN: c-index-test -read-diagnostics %t/macro_expand.dia 2>&1 | %FileCheck -check-prefix CHECK-DIAGS %s
 
 // RUN: %FileCheck %s  --check-prefix CHECK-MACRO-PRINTED < %t/macro-printing.txt
 
 // Debug info SIL testing
-// RUN: %target-swift-frontend -swift-version 5 -emit-sil -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-SIL %s
+// RUN: %target-swift-frontend -swift-version 5 -emit-sil -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-SIL %s
 
 // Debug info IR testing
-// RUN: %target-swift-frontend -swift-version 5 -emit-ir -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-IR %s
+// RUN: %target-swift-frontend -swift-version 5 -emit-ir -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-IR %s
 
 // Execution testing
-// RUN: %target-build-swift -swift-version 5 -g -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser
+// RUN: %target-build-swift -swift-version 5 -g -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser
 // RUN: %target-codesign %t/main
 // RUN: %target-run %t/main | %FileCheck %s
 
 // Plugin search path and loaded module trace testing
-// RUN: %target-swift-frontend -swift-version 5 -emit-sil -enable-experimental-feature FreestandingMacros -plugin-path %t %s -module-name MacroUser -emit-loaded-module-trace -o %t/loaded_module_trace
+// RUN: %target-swift-frontend -swift-version 5 -emit-sil -plugin-path %t %s -module-name MacroUser -emit-loaded-module-trace -o %t/loaded_module_trace
 // RUN: %FileCheck -check-prefix=CHECK-MODULE-TRACE %s < %t/loaded_module_trace.trace.json
 
 // CHECK-MODULE-TRACE: {{libMacroDefinition.dylib|libMacroDefinition.so|MacroDefinition.dll}}
diff --git a/test/Macros/macro_expand_closure.swift b/test/Macros/macro_expand_closure.swift
@@ -8,7 +8,7 @@
 
 
 // Debug info SIL testing
-// RUN: %target-swift-frontend -swift-version 5 -emit-sil -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-SIL %s
+// RUN: %target-swift-frontend -swift-version 5 -emit-sil -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser -o - -g | %FileCheck --check-prefix CHECK-SIL %s
 
 
 @freestanding(expression) public macro multiStatement() -> Int = #externalMacro(module: "MacroDefinition", type: "MultiStatementClosure")
diff --git a/test/Macros/macro_expand_codeitems.swift b/test/Macros/macro_expand_codeitems.swift
@@ -3,12 +3,12 @@
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath -swift-version 5
 
 // Diagnostics testing
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -enable-experimental-feature CodeItemMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS
-// RUN: %target-swift-frontend -swift-version 5 -emit-sil -enable-experimental-feature FreestandingMacros -enable-experimental-feature CodeItemMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -serialize-diagnostics-path %t/macro_expand_codeitems.dia %s -emit-macro-expansion-files no-diagnostics
+// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature CodeItemMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS
+// RUN: %target-swift-frontend -swift-version 5 -emit-sil -enable-experimental-feature CodeItemMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -serialize-diagnostics-path %t/macro_expand_codeitems.dia %s -emit-macro-expansion-files no-diagnostics
 // RUN: c-index-test -read-diagnostics %t/macro_expand_codeitems.dia 2>&1 | %FileCheck -check-prefix CHECK-DIAGS %s
 
 // Execution testing
-// RUN: %target-build-swift -swift-version 5 -g -enable-experimental-feature FreestandingMacros -enable-experimental-feature CodeItemMacros -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser
+// RUN: %target-build-swift -swift-version 5 -g -enable-experimental-feature CodeItemMacros -load-plugin-library %t/%target-library-name(MacroDefinition) %s -o %t/main -module-name MacroUser
 // RUN: %target-codesign %t/main
 // RUN: %target-run %t/main | %FileCheck %s
 
diff --git a/test/Macros/macro_expand_other.swift b/test/Macros/macro_expand_other.swift
@@ -4,10 +4,10 @@
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -parse-as-library -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
 
 // Diagnostics testing
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -module-name MacroUser -DTEST_DIAGNOSTICS
+// RUN: %target-typecheck-verify-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -module-name MacroUser -DTEST_DIAGNOSTICS
 
 // Execution testing
-// RUN: %target-build-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -L %swift-host-lib-dir %s -o %t/main -module-name MacroUser
+// RUN: %target-build-swift -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir -L %swift-host-lib-dir %s -o %t/main -module-name MacroUser
 // RUN: %target-codesign %t/main
 // RUN: %target-run %t/main | %FileCheck %s
 // REQUIRES: swift_swift_parser, executable_test
diff --git a/test/Macros/macros_diagnostics.swift b/test/Macros/macros_diagnostics.swift
@@ -1,6 +1,6 @@
 // REQUIRES: swift_swift_parser
 
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -enable-experimental-feature CodeItemMacros -module-name MacrosTest
+// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature CodeItemMacros -module-name MacrosTest
 
 @expression macro stringify<T>(_ value: T) -> (T, String) = #externalMacro(module: "MacroDefinition", type: "StringifyMacro")
 // expected-note@-1 2{{'stringify' declared here}}
diff --git a/test/Macros/macros_library_mode_diagnostics.swift b/test/Macros/macros_library_mode_diagnostics.swift
@@ -1,6 +1,6 @@
 // REQUIRES: swift_swift_parser
 
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -parse-as-library -module-name MacrosTest
+// RUN: %target-typecheck-verify-swift -swift-version 5 -parse-as-library -module-name MacrosTest
 
 // We need this test because top-level freestanding macro expansions are parsed
 // differently in library mode.
diff --git a/test/Macros/parsing.swift b/test/Macros/parsing.swift
@@ -1,6 +1,6 @@
 // REQUIRES: swift_swift_parser
 
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros
+// RUN: %target-typecheck-verify-swift -swift-version 5
 
 protocol P { }
 protocol Q { associatedtype Assoc }
diff --git a/test/Macros/top_level_freestanding.swift b/test/Macros/top_level_freestanding.swift
@@ -1,23 +1,23 @@
 // REQUIRES: swift_swift_parser, executable_test
 //
 // RUN: %empty-directory(%t)
-// RUN: %host-build-swift -swift-version 5 -parse-as-library -enable-experimental-feature FreestandingMacros -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
-// RUN: %target-swift-frontend -enable-experimental-feature FreestandingMacros -parse-as-library -emit-sil -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser 2>&1 | %FileCheck --check-prefix CHECK-SIL %s
+// RUN: %host-build-swift -swift-version 5 -parse-as-library -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
+// RUN: %target-swift-frontend -parse-as-library -emit-sil -load-plugin-library %t/%target-library-name(MacroDefinition) %s -module-name MacroUser 2>&1 | %FileCheck --check-prefix CHECK-SIL %s
 
 // Type check testing
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5  %S/Inputs/top_level_freestanding_other.swift
+// RUN: %target-typecheck-verify-swift -swift-version 5 -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5  %S/Inputs/top_level_freestanding_other.swift
 
 // Type check testing with imported macro declarations
 // RUN: %target-swift-frontend -swift-version 5 -emit-module -o %t/freestanding_macro_library.swiftmodule %S/Inputs/freestanding_macro_library.swift -module-name freestanding_macro_library -load-plugin-library %t/%target-library-name(MacroDefinition)
 
-// RUN: %target-typecheck-verify-swift -swift-version 5 -enable-experimental-feature FreestandingMacros -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -DIMPORT_MACRO_LIBRARY -swift-version 5  %S/Inputs/top_level_freestanding_other.swift -I %t
+// RUN: %target-typecheck-verify-swift -swift-version 5 -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -DIMPORT_MACRO_LIBRARY -swift-version 5  %S/Inputs/top_level_freestanding_other.swift -I %t
 
 // Check diagnostic buffer names
-// RUN: %target-swift-frontend -typecheck -swift-version 5 -enable-experimental-feature FreestandingMacros -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5 %s %S/Inputs/top_level_freestanding_other.swift 2> %t.diags
+// RUN: %target-swift-frontend -typecheck -swift-version 5 -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5 %s %S/Inputs/top_level_freestanding_other.swift 2> %t.diags
 // RUN: %FileCheck -check-prefix DIAG_BUFFERS %s < %t.diags
 
 // Execution testing
-// RUN: %target-build-swift -g -swift-version 5 -enable-experimental-feature FreestandingMacros -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) %s %S/Inputs/top_level_freestanding_other.swift -o %t/main -module-name MacroUser -swift-version 5
+// RUN: %target-build-swift -g -swift-version 5 -parse-as-library -load-plugin-library %t/%target-library-name(MacroDefinition) %s %S/Inputs/top_level_freestanding_other.swift -o %t/main -module-name MacroUser -swift-version 5
 // RUN: %target-codesign %t/main
 // RUN: %target-run %t/main | %FileCheck %s
 
diff --git a/test/SourceKit/Macros/macro_basic.swift b/test/SourceKit/Macros/macro_basic.swift
diff --git a/test/SymbolGraph/Symbols/Mixins/DeclarationFragments/Full/Macros.swift b/test/SymbolGraph/Symbols/Mixins/DeclarationFragments/Full/Macros.swift
