[test] Improve testing of Swift features

docs/Testing.md

@@ -549,6 +549,27 @@ FIXME: full list.
 * ``XFAIL: linux``: tests that need to be adapted for Linux, for example parts
   that depend on Objective-C interop need to be split out.
 
+#### Features ``REQUIRES: swift_feature_...``
+
+Each of the Swift compiler features defined in `include/swift/Basic/Features.def`
+will get a LLVM Lit feature prefixing `swift_feature_` to the feature name
+automatically. The LLVM Lit features will be available only in those
+configurations where the compiler supports the given feature, and will not be
+available when the compiler does not support the feature. This means that
+standard language features and upcoming features will always be available,
+while experimental features will only be available when the compiler supports
+them.
+
+For every test that uses `--enable-experimental-feature` or
+`--enable-upcoming-feature` add a `REQUIRES: swift_feature_...` for each of the
+used features. The `Misc/verify-swift-feature-testing.test-sh` will check that
+every test with those command line arguments have the necessary `REQUIRES:` and
+fail otherwise.
+
+Do NOT add `REQUIRES: asserts` for experimental features anymore. The correct
+usage of `REQUIRES: swift_feature_...` will take care of testing the feature as
+it evolves from experimental, to upcoming, to language feature.
+
 #### Feature ``REQUIRES: executable_test``
 
 This feature marks an executable test. The test harness makes this feature

test/ASTGen/attrs.swift

@@ -12,9 +12,8 @@
 
 // REQUIRES: executable_test
 // REQUIRES: swift_swift_parser
+// REQUIRES: swift_feature_ParserASTGen
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/decls.swift

@@ -13,9 +13,10 @@
 
 // REQUIRES: executable_test
 // REQUIRES: swift_swift_parser
+// REQUIRES: swift_feature_ParserASTGen
+// REQUIRES: swift_feature_SwiftParser
+// REQUIRES: swift_feature_ValueGenerics
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/diagnostics.swift

@@ -12,8 +12,7 @@
 // RUN: %target-typecheck-verify-swift -disable-availability-checking -enable-bare-slash-regex -enable-experimental-feature ParserASTGen
 
 // REQUIRES: swift_swift_parser
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
+// REQUIRES: swift_feature_ParserASTGen
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/do_expr.swift

@@ -12,8 +12,8 @@
 // RUN: %target-typecheck-verify-swift -disable-availability-checking -enable-experimental-feature DoExpressions -enable-experimental-feature ParserASTGen
 
 // REQUIRES: swift_swift_parser
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
+// REQUIRES: swift_feature_DoExpressions
+// REQUIRES: swift_feature_ParserASTGen
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/exprs.swift

@@ -13,9 +13,9 @@
 
 // REQUIRES: executable_test
 // REQUIRES: swift_swift_parser
+// REQUIRES: swift_feature_ParserASTGen
+// REQUIRES: swift_feature_SwiftParser
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/if_config.swift

@@ -1,6 +1,6 @@
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature ParserASTGen -DDISCARDABLE -DNONSENDABLE -swift-version 6
-/// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
+
+// REQUIRES: swift_feature_ParserASTGen
 
 #if NOT_SET
 func f { } // expected-error{{expected parameter clause in function signature}}

test/ASTGen/if_config_expr.swift

@@ -1,8 +1,7 @@
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature ParserASTGen -D CONDITION_1
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
 // REQUIRES: swift_swift_parser
+// REQUIRES: swift_feature_ParserASTGen
 
 postfix operator ++
 postfix func ++ (_: Int) -> Int { 0 }

test/ASTGen/macros.swift

@@ -1,4 +1,5 @@
 // REQUIRES: swift_swift_parser, asserts
+// REQUIRES: swift_feature_ParserASTGen
 
 // RUN: %empty-directory(%t)
 

test/ASTGen/regex.swift

@@ -11,9 +11,8 @@
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature ParserASTGen -enable-bare-slash-regex -disable-availability-checking
 
 // REQUIRES: swift_swift_parser
+// REQUIRES: swift_feature_ParserASTGen
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/stmts.swift

@@ -12,9 +12,10 @@
 
 // REQUIRES: executable_test
 // REQUIRES: swift_swift_parser
+// REQUIRES: swift_feature_ParserASTGen
+// REQUIRES: swift_feature_SwiftParser
+// REQUIRES: swift_feature_ThenStatements
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/top_level.swift

@@ -8,8 +8,8 @@
 
 // RUN: %diff -u %t/astgen.ast %t/cpp-parser.ast
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
+// REQUIRES: swift_feature_ParserASTGen
+
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/ASTGen/types.swift

@@ -1,7 +1,7 @@
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature ParserASTGen
 
-// -enable-experimental-feature requires an asserts build
-// REQUIRES: asserts
+// REQUIRES: swift_feature_ParserASTGen
+
 // rdar://116686158
 // UNSUPPORTED: asan
 

test/AssociatedTypeInference/associated_type_tuple.swift

@@ -1,6 +1,6 @@
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature TupleConformances
 
-// REQUIRES: asserts
+// REQUIRES: swift_feature_TupleConformances
 
 typealias Tuple<each T> = (repeat each T)
 

test/CAS/block-list.swift

@@ -40,6 +40,9 @@
 // RUN:   -cache-replay-prefix-map /^tmp=%t \
 // RUN:   /^tmp/main.swift @%t/MyApp.cmd 2>&1 | %FileCheck %s --check-prefix CHECK-BLOCKED
 
+// REQUIRES: swift_feature_LayoutStringValueWitnesses
+// REQUIRES: swift_feature_LayoutStringValueWitnessesInstantiation
+
 // CHECK-BLOCKED: note: Layout string value witnesses have been disabled for module 'Test' through block list entry
 // CHECK-BLOCKED-NOT: type_layout_string
 

test/CMakeLists.txt

@@ -253,6 +253,16 @@ if(NOT "${COVERAGE_DB}" STREQUAL "")
       COMMENT "Touching covering tests")
 endif()
 
+if(SWIFT_COMPILER_IS_MSVC_LIKE)
+  set(C_PREPROCESSOR_COMMAND
+    "${CMAKE_C_COMPILER}" "/P" "/EP" "/I" "${SWIFT_MAIN_INCLUDE_DIR}" "/TC"
+    "/Fi<<<OUTPUT_FILE>>>")
+else()
+  set(C_PREPROCESSOR_COMMAND
+    "${CMAKE_C_COMPILER}" "-E" "-P" "-I${SWIFT_MAIN_INCLUDE_DIR}" "-x" "c" "-o"
+    "<<<OUTPUT_FILE>>>")
+endif()
+
 foreach(SDK ${SWIFT_SDKS})
   foreach(ARCH ${SWIFT_SDK_${SDK}_ARCHITECTURES})
     # macCatalyst needs to run two sets of tests: one with the normal macosx target triple
@@ -304,6 +314,38 @@ foreach(SDK ${SWIFT_SDKS})
           "${validation_test_bin_dir}/lit.site.cfg"
           "validation-test${VARIANT_SUFFIX}.lit.site.cfg")
 
+      set(test_lit_swift_features_cmd ${C_PREPROCESSOR_COMMAND})
+      list(
+        TRANSFORM test_lit_swift_features_cmd
+        REPLACE "<<<OUTPUT_FILE>>>" "${test_bin_dir}/lit.swift-features.cfg")
+      add_custom_command(
+        OUTPUT "${test_bin_dir}/lit.swift-features.cfg"
+        COMMAND
+          ${test_lit_swift_features_cmd}
+          "${CMAKE_CURRENT_SOURCE_DIR}/lit.swift-features.cfg.inc"
+        DEPENDS
+          "lit.swift-features.cfg.inc"
+          "${SWIFT_MAIN_INCLUDE_DIR}/swift/Basic/Features.def"
+      )
+
+      set(validation_test_lit_swift_features_cmd ${C_PREPROCESSOR_COMMAND})
+      list(
+        TRANSFORM validation_test_lit_swift_features_cmd
+        REPLACE "<<<OUTPUT_FILE>>>" "${validation_test_bin_dir}/lit.swift-features.cfg")
+      add_custom_command(
+        OUTPUT "${validation_test_bin_dir}/lit.swift-features.cfg"
+        COMMAND
+          ${validation_test_lit_swift_features_cmd}
+          "${CMAKE_CURRENT_SOURCE_DIR}/lit.swift-features.cfg.inc"
+        DEPENDS
+          "lit.swift-features.cfg.inc"
+          "${SWIFT_MAIN_INCLUDE_DIR}/swift/Basic/Features.def"
+      )
+      add_custom_target(lit_swift_features_cfg_${VARIANT_SUFFIX}
+        DEPENDS
+          "${test_bin_dir}/lit.swift-features.cfg"
+          "${validation_test_bin_dir}/lit.swift-features.cfg")
+
       set(test_dependencies)
       get_test_dependencies("${SDK}" test_dependencies)
 
@@ -341,6 +383,9 @@ foreach(SDK ${SWIFT_SDKS})
 
       set(validation_test_dependencies)
 
+      list(APPEND test_dependencies lit_swift_features_cfg_${VARIANT_SUFFIX})
+      list(APPEND validation_test_dependencies lit_swift_features_cfg_${VARIANT_SUFFIX})
+
       set(command_upload_stdlib)
       set(command_upload_swift_reflection_test)
       if("${SDK}" STREQUAL "IOS" OR "${SDK}" STREQUAL "TVOS" OR "${SDK}" STREQUAL "WATCHOS" OR "${SDK}" STREQUAL "XROS")

test/ClangImporter/dynamic_actor_isolation_checks.swift

@@ -4,9 +4,9 @@
 // RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -disable-availability-checking -enable-upcoming-feature DynamicActorIsolation -emit-silgen -module-name preconcurrency_conformances %t/src/checks.swift | %FileCheck %t/src/checks.swift
 // RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -disable-availability-checking -swift-version 6 -disable-dynamic-actor-isolation -emit-silgen -module-name preconcurrency_conformances %t/src/checks_disabled.swift | %FileCheck %t/src/checks_disabled.swift
 
-// REQUIRES: asserts
 // REQUIRES: concurrency
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_DynamicActorIsolation
 
 //--- checks.swift
 import Foundation

test/ClangImporter/incomplete_objc_types_availability.swift

@@ -10,6 +10,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 // Verify that Clang declarations referencing either of the forward declares types "ForwardDeclaredInterface" or
 // "ForwardDeclaredProtocol" are usable from Swift.

test/ClangImporter/incomplete_objc_types_base_interface.swift

@@ -8,6 +8,7 @@
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
 // REQUIRES: OS=macosx
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 import Foundation
 import IncompleteTypeLibrary1

test/ClangImporter/incomplete_objc_types_bridging_header.swift

@@ -1,6 +1,7 @@
 // RUN: %target-swift-frontend -import-objc-header %S/Inputs/incomplete_objc_types_bridging_header.h -enable-upcoming-feature ImportObjcForwardDeclarations -enable-objc-interop -typecheck %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 let foo = CFunctionReturningAForwardDeclaredInterface()
 CFunctionTakingAForwardDeclaredInterface(foo)

test/ClangImporter/incomplete_objc_types_compatibility_complete_incomplete.swift

@@ -11,6 +11,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 // "ForwardDeclaredInterface" and "ForwardDeclaredProtocol" are forward declared in IncompleteTypeLibrary1/2, and
 // completely declared in CompleteTypes. This test verifies that instances of the complete types can be passed

test/ClangImporter/incomplete_objc_types_compatibility_complete_incomplete_inter_file_clang_definition.swift

@@ -9,6 +9,7 @@
 
 // REQUIRES: executable_test
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 //--- full_definition.swift
 

test/ClangImporter/incomplete_objc_types_compatibility_complete_incomplete_inter_file_swift_definition.swift

@@ -5,6 +5,7 @@
 // RUN: not %target-swift-frontend -enable-upcoming-feature ImportObjcForwardDeclarations -enable-objc-interop -typecheck -I %S/Inputs/custom-modules/IncompleteTypes -I %t %t/incomplete_definition.swift %t/full_definition.swift -diagnostic-style llvm 2>&1 | %FileCheck %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 //--- full_definition.swift
 

test/ClangImporter/incomplete_objc_types_compatibility_incomplete_incomplete.swift

@@ -11,6 +11,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 // Both libraries "IncompleteTypeConsumer1" and "IncompleteTypeConsumer2" forward declare an interface "ForwardDeclaredInterface"
 // and a protocol "ForwardDeclaredProtocol". This test verifies that the synthesized Swift declaration created to represent

test/ClangImporter/incomplete_objc_types_full_availability.swift

@@ -7,6 +7,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
+// REQUIRES: swift_feature_ImportObjCForwardDeclarations
 
 import IncompleteTypeLibrary1
 import CompleteTypes

test/ClangImporter/incomplete_objc_types_importing_limitations_diagnostics.swift

@@ -2,6 +2,7 @@
 // RUN: not %target-swift-frontend -swift-version 6 -enable-objc-interop -typecheck -I %S/Inputs/custom-modules/IncompleteTypes %s -diagnostic-style llvm 2>&1 | %FileCheck  %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 import IncompleteTypeLibrary1
 import IncompleteNoRootTypeProtocolLibrary

test/ClangImporter/incomplete_objc_types_no_reference.swift

@@ -2,6 +2,7 @@
 // RUN: not %target-swift-frontend -swift-version 6 -enable-objc-interop -typecheck -I %S/Inputs/custom-modules/IncompleteTypes %s 2>&1 | %FileCheck %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 import IncompleteTypeLibrary1
 

test/ClangImporter/incomplete_objc_types_no_root_protocol.swift

@@ -9,6 +9,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 // Verify that a forward declared protocol not inheriting from NSObject is usable
 // from Swift, if cumbersome

test/ClangImporter/incomplete_objc_types_nsproxy.swift

@@ -9,6 +9,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 // Verify that a forward declared interface for a type inheriting from NSProxy instead
 // of NSObject is still usable from Swift.

test/ClangImporter/incomplete_objc_types_swift_definition_imported.swift

@@ -4,6 +4,7 @@
 // RUN: not %target-swift-frontend -swift-version 6 -enable-objc-interop -typecheck -I %S/Inputs/custom-modules/IncompleteTypes -I %t %s -diagnostic-style llvm 2>&1 | %FileCheck  %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 import CompleteSwiftTypes
 import ObjCLibraryForwardDeclaringCompleteSwiftTypes

test/ClangImporter/incomplete_objc_types_swift_definition_imported_implementationOnly.swift

@@ -4,6 +4,7 @@
 // RUN: not %target-swift-frontend -swift-version 6 -enable-objc-interop -typecheck -I %S/Inputs/custom-modules/IncompleteTypes -I %t %s -diagnostic-style llvm 2>&1 | %FileCheck  %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 @_implementationOnly import CompleteSwiftTypes
 import ObjCLibraryForwardDeclaringCompleteSwiftTypes

test/ClangImporter/incomplete_objc_types_swift_definition_imported_name_conflict.swift

@@ -4,6 +4,7 @@
 // RUN: not %target-swift-frontend -swift-version 6 -enable-objc-interop -typecheck -I %S/Inputs/custom-modules/IncompleteTypes -I %t %s -diagnostic-style llvm 2>&1 | %FileCheck  %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 import CompleteSwiftTypes
 import ObjCLibraryForwardDeclaringCompleteSwiftTypes

test/ClangImporter/incomplete_objc_types_swift_definition_imported_shadow_type_mismatch.swift

@@ -6,6 +6,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: executable_test
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 import CompleteSwiftTypes
 import ObjCLibraryForwardDeclaringCompleteSwiftTypes

test/ClangImporter/incomplete_objc_types_swift_ide_test.swift

@@ -11,6 +11,7 @@
 // RUN:     -enable-objc-interop -swift-version 6 -source-filename x | %FileCheck %s
 
 // REQUIRES: objc_interop
+// REQUIRES: swift_feature_ImportObjcForwardDeclarations
 
 // CHECK: import Foundation
 // CHECK: @available(*, unavailable, message: "This Objective-C class has only been forward-declared; import its owning module to use it")

test/ClangImporter/objc_async.swift

@@ -2,7 +2,7 @@
 
 // REQUIRES: objc_interop
 // REQUIRES: concurrency
-// REQUIRES: asserts
+// REQUIRES: swift_feature_SendableCompletionHandlers
 
 import Foundation
 import ObjCConcurrency