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[Runtime] Add a disabled workaround for protocol conformance checking to check conformances in reverse order.
rdar://problem/72049977
1 parent af8cf15 commit 9ac3b0e

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6 files changed

+186
-3
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6 files changed

+186
-3
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‎include/swift/Runtime/Bincompat.h‎

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//===--- Bincompat.h - Binary compatibility checks. -------------*- C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// Checks for enabling binary compatibility workarounds.
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//
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//===----------------------------------------------------------------------===//
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namespace swift {
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namespace runtime {
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namespace bincompat {
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/// Whether protocol conformance iteration should be reversed, to prefer
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/// conformances from images that are later in the list over earlier ones.
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bool workaroundProtocolConformanceReverseIteration();
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} // namespace bincompat
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} // namespace runtime
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} // namespace swift

‎stdlib/public/runtime/Bincompat.cpp‎

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//===--- Bincompat.cpp - Binary compatibility checks. -----------*- C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// Checks for enabling binary compatibility workarounds.
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//
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//===----------------------------------------------------------------------===//
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#include "swift/Runtime/Bincompat.h"
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namespace swift {
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namespace runtime {
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namespace bincompat {
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bool workaroundProtocolConformanceReverseIteration() { return false; }
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} // namespace bincompat
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} // namespace runtime
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} // namespace swift

‎stdlib/public/runtime/CMakeLists.txt‎

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@@ -30,6 +30,7 @@ set(swift_runtime_sources
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Array.cpp
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AutoDiffSupport.cpp
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BackDeployment.cpp
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Bincompat.cpp
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Casting.cpp
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CompatibilityOverride.cpp
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CygwinPort.cpp

‎stdlib/public/runtime/ProtocolConformance.cpp‎

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@@ -16,6 +16,7 @@
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#include "swift/Basic/Lazy.h"
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#include "swift/Demangling/Demangle.h"
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#include "swift/Runtime/Bincompat.h"
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#include "swift/Runtime/Casting.h"
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#include "swift/Runtime/Concurrent.h"
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#include "swift/Runtime/HeapObject.h"
@@ -238,8 +239,11 @@ namespace {
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struct ConformanceState {
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ConcurrentReadableHashMap<ConformanceCacheEntry> Cache;
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ConcurrentReadableArray<ConformanceSection> SectionsToScan;
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bool scanSectionsBackwards;
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ConformanceState() {
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scanSectionsBackwards =
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runtime::bincompat::workaroundProtocolConformanceReverseIteration();
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initializeProtocolConformanceLookup();
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}
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@@ -466,8 +470,7 @@ swift_conformsToProtocolImpl(const Metadata *const type,
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return found.second;
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// Scan conformance records.
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auto snapshot = C.SectionsToScan.snapshot();
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for (auto &section : snapshot) {
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auto processSection = [&](const ConformanceSection &section) {
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// Eagerly pull records for nondependent witnesses into our cache.
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for (const auto &record : section) {
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auto &descriptor = *record.get();
@@ -485,6 +488,15 @@ swift_conformsToProtocolImpl(const Metadata *const type,
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C.cacheResult(matchingType, protocol, witness, /*always cache*/ 0);
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}
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}
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};
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auto snapshot = C.SectionsToScan.snapshot();
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if (C.scanSectionsBackwards) {
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for (auto &section : llvm::reverse(snapshot))
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processSection(section);
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} else {
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for (auto &section : snapshot)
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processSection(section);
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}
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// Try the search again to look for the most specific cached conformance.

‎test/Runtime/protocol_conformance_collision.swift‎

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// RUN: %empty-directory(%t)
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// RUN: %target-build-swift %s -o %t/newSDK %target-link-sdk-future-version
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// RUN: %target-codesign %t/newSDK
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// RUN: %target-run %t/newSDK newSDK
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// RUN: %target-build-swift %s -o %t/oldSDK %target-link-sdk-2020-version
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// RUN: %target-codesign %t/oldSDK
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// RUN: %target-run %t/oldSDK oldSDK
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// REQUIRES: VENDOR=apple
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// Simulators refuse to run binaries built with an SDK newer than the simulator.
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// UNSUPPORTED: DARWIN_SIMULATOR=ios
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// UNSUPPORTED: DARWIN_SIMULATOR=tvos
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// UNSUPPORTED: DARWIN_SIMULATOR=watchos
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import Accelerate
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import Foundation
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import StdlibUnittest
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import SwiftShims
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extension CFString: Hashable {
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static var localHashableCallCount = 0
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public var hashValue: Int {
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Self.localHashableCallCount += 1
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return (self as String).hashValue
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}
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}
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protocol P {
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func firstHashValue() -> Int
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}
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extension Set: P {
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func firstHashValue() -> Int {
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return first!.hashValue
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}
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}
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@_optimize(none)
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func firstHashValue(_ x: P) -> Int {
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x.firstHashValue()
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}
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let osHasWorkaround: Bool
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// These are deliberately NOT version 9999, as we don't want to hit the special
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// case where development runtimes always return true for 9999. This check needs
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// to be false until real version numbers are put in.
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if #available(macOS 99990, iOS 99990, tvOS 99990, watchOS 99990, *) {
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osHasWorkaround = true
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} else {
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osHasWorkaround = false
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}
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let testingOldSDK = CommandLine.arguments.last == "oldSDK"
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var tests: TestSuite
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if testingOldSDK {
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tests = TestSuite("old SDK protocol conformance collision")
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tests.test("CFString: Hashable conformance") {
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_ = firstHashValue(NSSet(object: "Whatever") as! Set<CFString>)
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let expectedCallCount = osHasWorkaround ? 1 : 0
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expectEqual(expectedCallCount, CFString.localHashableCallCount)
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}
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} else {
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tests = TestSuite("new SDK protocol conformance collision")
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tests.test("CFString: Hashable conformance") {
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_ = firstHashValue(NSSet(object: "Whatever") as! Set<CFString>)
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expectEqual(0, CFString.localHashableCallCount)
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}
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}
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runAllTests()

‎test/lit.cfg‎

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@@ -1107,6 +1107,31 @@ if run_vendor == 'apple':
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config.otool_classic = ("%s otool-classic" % (xcrun_prefix))
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SDK_2020_VERSION = {
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'macosx': '11.0',
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'ios': '14.0',
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'maccatalyst': '14.0',
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'tvos': '14.0',
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'watchos': '7.0'
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}
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sdk_2020_version = SDK_2020_VERSION.get(run_os, '')
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linker_os = {
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'iphoneos': 'ios',
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'appletvos': 'tvos',
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'watchos': 'watchos',
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'iphonesimulator': 'ios-simulator',
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'watchsimulator': 'watchos-simulator',
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'appletvsimulator': 'tvos-simulator',
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'macosx': 'macos'
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}.get(config.target_sdk_name, run_os)
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config.target_link_sdk_2020_version = (
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"-Xlinker -platform_version -Xlinker %s -Xlinker %s -Xlinker %s" %
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(linker_os, sdk_2020_version, sdk_2020_version))
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config.target_link_sdk_future_version = (
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"-Xlinker -platform_version -Xlinker %s -Xlinker %s -Xlinker %s" %
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(linker_os, target_future_version, target_future_version))
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elif run_os in ['windows-msvc']:
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lit_config.note('Testing Windows ' + config.variant_triple)
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config.environment['NUMBER_OF_PROCESSORS'] = os.environ['NUMBER_OF_PROCESSORS']
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if hasattr(config, 'otool_classic'):
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config.substitutions.append(('%otool-classic', config.otool_classic))
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if hasattr(config, 'target_link_sdk_2020_version'):
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config.substitutions.append(('%target-link-sdk-2020-version',
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config.target_link_sdk_2020_version))
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if hasattr(config, 'target_link_sdk_future_version'):
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config.substitutions.append(('%target-link-sdk-future-version',
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config.target_link_sdk_future_version))
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run_filecheck = '%s %s --sanitize BUILD_DIR=%s --sanitize SOURCE_DIR=%s --use-filecheck %s %s' % (
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shell_quote(sys.executable),
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shell_quote(config.PathSanitizingFileCheck),

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