Start a Compatibility51 library for backporting fixes to Swift 5.1 runtimes

Author: jckarter

lib/Basic/Platform.cpp

@@ -406,22 +406,34 @@ swift::getSwiftRuntimeCompatibilityVersionForTarget(
       if (Minor <= 14) {
         return llvm::VersionTuple(5, 0);
       } else if (Minor <= 15) {
-        return llvm::VersionTuple(5, 1);
+        if (Micro <= 3) {
+          return llvm::VersionTuple(5, 1);
+        } else {
+          return llvm::VersionTuple(5, 2);
+        }
       }
     }
   } else if (Triple.isiOS()) { // includes tvOS
     Triple.getiOSVersion(Major, Minor, Micro);
     if (Major <= 12) {
       return llvm::VersionTuple(5, 0);
     } else if (Major <= 13) {
-      return llvm::VersionTuple(5, 1);
+      if (Minor <= 3) {
+        return llvm::VersionTuple(5, 1);
+      } else {
+        return llvm::VersionTuple(5, 2);
+      }
     }
   } else if (Triple.isWatchOS()) {
     Triple.getWatchOSVersion(Major, Minor, Micro);
     if (Major <= 5) {
       return llvm::VersionTuple(5, 0);
     } else if (Major <= 6) {
-      return llvm::VersionTuple(5, 1);
+      if (Minor <= 1) {
+        return llvm::VersionTuple(5, 1);
+      } else {
+        return llvm::VersionTuple(5, 2);
+      }
     }
   }
 

lib/Driver/DarwinToolChains.cpp

@@ -345,6 +345,8 @@ toolchains::Darwin::addArgsToLinkStdlib(ArgStringList &Arguments,
                                     options::OPT_runtime_compatibility_version);
     if (value.equals("5.0")) {
       runtimeCompatibilityVersion = llvm::VersionTuple(5, 0);
+    } else if (value.equals("5.1")) {
+      runtimeCompatibilityVersion = llvm::VersionTuple(5, 1);
     } else if (value.equals("none")) {
       runtimeCompatibilityVersion = None;
     } else {
@@ -367,6 +369,18 @@ toolchains::Darwin::addArgsToLinkStdlib(ArgStringList &Arguments,
         Arguments.push_back(context.Args.MakeArgString(BackDeployLib));
       }
     }
+
+    if (*runtimeCompatibilityVersion <= llvm::VersionTuple(5, 1)) {
+      // Swift 5.1 compatibility library
+      SmallString<128> BackDeployLib;
+      BackDeployLib.append(SharedResourceDirPath);
+      llvm::sys::path::append(BackDeployLib, "libswiftCompatibility51.a");
+      
+      if (llvm::sys::fs::exists(BackDeployLib)) {
+        Arguments.push_back("-force_load");
+        Arguments.push_back(context.Args.MakeArgString(BackDeployLib));
+      }
+    }
   }
 
   if (job.getKind() == LinkKind::Executable) {

lib/Frontend/CompilerInvocation.cpp

@@ -1413,6 +1413,8 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
         runtimeCompatibilityVersion = None;
       } else if (version.equals("5.0")) {
         runtimeCompatibilityVersion = llvm::VersionTuple(5, 0);
+      } else if (version.equals("5.1")) {
+        runtimeCompatibilityVersion = llvm::VersionTuple(5, 1);
       } else {
         Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
                        versionArg->getAsString(Args), version);

lib/IRGen/GenDecl.cpp

@@ -476,6 +476,11 @@ void IRGenModule::emitSourceFile(SourceFile &SF) {
                                          LibraryKind::Library,
                                          /*forceLoad*/ true));
       }
+      if (*compatibilityVersion <= llvm::VersionTuple(5, 1)) {
+        this->addLinkLibrary(LinkLibrary("swiftCompatibility51",
+                                         LibraryKind::Library,
+                                         /*forceLoad*/ true));
+      }
     }
 
     if (auto compatibilityVersion =

stdlib/toolchain/CMakeLists.txt

@@ -59,4 +59,5 @@ endif()
 
 add_subdirectory(legacy_layouts)
 add_subdirectory(Compatibility50)
+add_subdirectory(Compatibility51)
 add_subdirectory(CompatibilityDynamicReplacements)

stdlib/toolchain/Compatibility50/Overrides.cpp

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -30,7 +30,7 @@ struct OverrideSection {
 #include "../../public/runtime/CompatibilityOverride.def"
 };
 
-OverrideSection Overrides
+OverrideSection Swift50Overrides
 __attribute__((used, section("__DATA,__swift_hooks"))) = {
   .version = 0,
   .conformsToProtocol = swift50override_conformsToProtocol,

stdlib/toolchain/Compatibility51/CMakeLists.txt

@@ -0,0 +1,29 @@
+
+set(library_name "swiftCompatibility51")
+
+add_swift_target_library("${library_name}" STATIC
+  Overrides.cpp
+
+  TARGET_SDKS ${SWIFT_APPLE_PLATFORMS}
+
+  C_COMPILE_FLAGS ${CXX_COMPILE_FLAGS}
+  LINK_FLAGS ${CXX_LINK_FLAGS}
+  SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
+
+  INSTALL_IN_COMPONENT compiler
+  INSTALL_WITH_SHARED)
+
+
+# FIXME: We need a more flexible mechanism to add lipo targets generated by
+# add_swift_target_library to the ALL target. Until then this hack is necessary
+# to ensure these libraries build.
+foreach(sdk ${SWIFT_SDKS})
+  set(target_name "${library_name}-${SWIFT_SDK_${sdk}_LIB_SUBDIR}")
+  if(NOT TARGET "${target_name}")
+    continue()
+  endif()
+
+  set_target_properties("${target_name}"
+    PROPERTIES
+      EXCLUDE_FROM_ALL FALSE)
+endforeach()

stdlib/toolchain/Compatibility51/Overrides.cpp

@@ -0,0 +1,40 @@
+//===--- Overrides.cpp - Compat override table for Swift 5.1 runtime ------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file provides compatibility override hooks for Swift 5.1 runtimes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "../../public/runtime/CompatibilityOverride.h"
+
+#include <dlfcn.h>
+#include <mach-o/dyld.h>
+#include <mach-o/getsect.h>
+
+using namespace swift;
+
+struct OverrideSection {
+  uintptr_t version;
+#define OVERRIDE(name, ret, attrs, ccAttrs, namespace, typedArgs, namedArgs) \
+  Override_ ## name name;
+#include "../../public/runtime/CompatibilityOverride.def"
+};
+  
+OverrideSection Swift51Overrides
+__attribute__((used, section("__DATA,__swift51_hooks"))) = {
+  .version = 0,
+};
+
+// Allow this library to get force-loaded by autolinking
+__attribute__((weak, visibility("hidden")))
+extern "C"
+char _swift_FORCE_LOAD_$_swiftCompatibility51 = 0;

test/IRGen/autolink-runtime-compatibility.swift

@@ -10,19 +10,35 @@
 // Doesn't autolink compatibility library because target OS doesn't need it
 // RUN: %target-swift-frontend -target x86_64-apple-macosx10.24 -emit-ir -parse-stdlib %s | %FileCheck -check-prefix=NO-FORCE-LOAD %s
 
+// Only autolinks 5.1 compatibility library because target OS has 5.1
+// RUN: %target-swift-frontend -target x86_64-apple-macosx10.15 -emit-ir -parse-stdlib %s | %FileCheck -check-prefix=FORCE-LOAD-51 %s
+
 // Autolinks because compatibility library was explicitly asked for
 // RUN: %target-swift-frontend -runtime-compatibility-version 5.0 -emit-ir -parse-stdlib %s | %FileCheck -check-prefix=FORCE-LOAD %s
+// RUN: %target-swift-frontend -runtime-compatibility-version 5.1 -emit-ir -parse-stdlib %s | %FileCheck -check-prefix=FORCE-LOAD-51 %s
 // RUN: %target-swift-frontend -target x86_64-apple-macosx10.24 -runtime-compatibility-version 5.0 -emit-ir -parse-stdlib %s | %FileCheck -check-prefix=FORCE-LOAD %s
+// RUN: %target-swift-frontend -target x86_64-apple-macosx10.24 -runtime-compatibility-version 5.1 -emit-ir -parse-stdlib %s | %FileCheck -check-prefix=FORCE-LOAD-51 %s
 
 public func foo() {}
 
 // NO-FORCE-LOAD-NOT: FORCE_LOAD
 // NO-FORCE-LOAD-NOT: !{!"-lswiftCompatibility50"}
+// NO-FORCE-LOAD-NOT: !{!"-lswiftCompatibility51"}
 // NO-FORCE-LOAD-NOT: !{!"-lswiftCompatibilityDynamicReplacements"}
 
 // FORCE-LOAD: declare {{.*}} @"_swift_FORCE_LOAD_$_swiftCompatibility50"
 // FORCE-LOAD: declare {{.*}} @"_swift_FORCE_LOAD_$_swiftCompatibilityDynamicReplacements"
-
 // FORCE-LOAD-DAG: [[AUTOLINK_SWIFT_COMPAT:![0-9]+]] = !{!"-lswiftCompatibility50"}
+// FORCE-LOAD-DAG: !{!"-lswiftCompatibility51"}
 // FORCE-LOAD-DAG: !{!"-lswiftCompatibilityDynamicReplacements"}
 // FORCE-LOAD-DAG: !llvm.linker.options = !{{{.*}}[[AUTOLINK_SWIFT_COMPAT]]{{[,}]}}
+
+// FORCE-LOAD-51-NOT: @"_swift_FORCE_LOAD_$_swiftCompatibility50"
+// FORCE-LOAD-51-NOT: @"_swift_FORCE_LOAD_$_swiftCompatibilityDynamicReplacements"
+// FORCE-LOAD-51: declare {{.*}} @"_swift_FORCE_LOAD_$_swiftCompatibility51"
+// FORCE-LOAD-51-NOT: @"_swift_FORCE_LOAD_$_swiftCompatibility50"
+// FORCE-LOAD-51-NOT: @"_swift_FORCE_LOAD_$_swiftCompatibilityDynamicReplacements"
+// FORCE-LOAD-51-DAG: [[AUTOLINK_SWIFT_COMPAT:![0-9]+]] = !{!"-lswiftCompatibility51"}
+// FORCE-LOAD-51-DAG: !llvm.linker.options = !{{{.*}}[[AUTOLINK_SWIFT_COMPAT]]{{[,}]}}
+// FORCE-LOAD-51-NOT: @"_swift_FORCE_LOAD_$_swiftCompatibility50"
+// FORCE-LOAD-51-NOT: @"_swift_FORCE_LOAD_$_swiftCompatibilityDynamicReplacements"

test/stdlib/Compatibility50Linking.c

@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-clang %s -all_load %test-resource-dir/%target-sdk-name/libswiftCompatibility50.a -lobjc -o %t/main
+// RUN: %target-clang %s -all_load %test-resource-dir/%target-sdk-name/libswiftCompatibility50.a %test-resource-dir/%target-sdk-name/libswiftCompatibility51.a -lobjc -o %t/main
 // RUN: %target-run %t/main
 // REQUIRES: objc_interop
 // REQUIRES: executable_test