runtime: Move String implementation stubs that want need the auto-rel…

stdlib/public/stubs/CMakeLists.txt

@@ -11,6 +11,7 @@ set(swift_stubs_objc_sources
     FoundationHelpers.mm
     OptionalBridgingHelper.mm
     Reflection.mm
+    SwiftNativeNSXXXBaseARC.m
     SwiftNativeNSXXXBase.mm.gyb)
 set(swift_stubs_unicode_normalization_sources
     UnicodeNormalization.cpp)
@@ -41,3 +42,7 @@ add_swift_library(swiftStdlibStubs OBJECT_LIBRARY TARGET_LIBRARY
   LINK_FLAGS ${SWIFT_RUNTIME_CORE_LINK_FLAGS}
   INSTALL_IN_COMPONENT stdlib)
 
+if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
+  set_property(SOURCE SwiftNativeNSXXXBaseARC.m APPEND_STRING PROPERTY COMPILE_FLAGS
+    "-fobjc-arc")
+endif()

stdlib/public/stubs/SwiftNativeNSXXXBase.mm.gyb

@@ -143,25 +143,6 @@ swift_stdlib_CFStringHashCString(const uint8_t *bytes, CFIndex len) {
   return Result;
 }
 
-SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
-size_t
-swift_stdlib_NSStringHashValue(NSString *NS_RELEASES_ARGUMENT str,
-                               bool isASCII) {
-  size_t Result =
-      isASCII ? str.hash : str.decomposedStringWithCanonicalMapping.hash;
-
-  swift_unknownRelease(str);
-  return Result;
-}
-
-SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
-size_t
-swift_stdlib_NSStringHashValuePointer(void *opaque, bool isASCII) {
-  NSString *str = (NSString *)opaque;
-  return isASCII ? str.hash : str.decomposedStringWithCanonicalMapping.hash;
-}
-
-
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 bool swift_stdlib_NSStringHasPrefixNFD(NSString *theString,
                                        NSString *prefix) {
@@ -211,22 +192,6 @@ bool swift_stdlib_NSStringHasSuffixNFDPointer(void *theString,
   return Result;
 }
 
-SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
-NS_RETURNS_RETAINED NSString *
-swift_stdlib_NSStringLowercaseString(NSString *NS_RELEASES_ARGUMENT str) {
-  NSString *Result = objc_retain(str.lowercaseString);
-  swift_unknownRelease(str);
-  return Result;
-}
-
-SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
-NS_RETURNS_RETAINED NSString *
-swift_stdlib_NSStringUppercaseString(NSString *NS_RELEASES_ARGUMENT str) {
-  NSString *Result = objc_retain(str.uppercaseString);
-  swift_unknownRelease(str);
-  return Result;
-}
-
 SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
 void swift_stdlib_CFSetGetValues(NSSet *NS_RELEASES_ARGUMENT set,
                                             const void **values) {

stdlib/public/stubs/SwiftNativeNSXXXBaseARC.m

@@ -0,0 +1,75 @@
+//===--- SwiftNativeNSXXXBaseARC.mm - Runtime stubs that require ARC ------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 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
+//
+//===----------------------------------------------------------------------===//
+#include "swift/Runtime/Config.h"
+
+#if SWIFT_OBJC_INTEROP
+
+#import <Foundation/Foundation.h>
+#import <CoreFoundation/CoreFoundation.h>
+#include <objc/NSObject.h>
+#include <objc/runtime.h>
+#include <objc/objc.h>
+
+// The following two routines need to be implemented in ARC because
+// decomposedStringWithCanonicalMapping returns its result autoreleased. And we
+// want ARC to insert 'objc_retainAutoreleasedReturnValue' and the necessary
+// markers for the hand-off to facilitate the remove from autorelease pool
+// optimization such that the object is not handed into the current autorelease
+// pool which might be scoped such that repeatedly placing objects into it
+// results in unbounded memory growth.
+
+// On i386 the remove from autorelease pool optimization is foiled by the
+// decomposedStringWithCanonicalMapping implementation. Instead, we use a local
+// autorelease pool to prevent leaking of the temporary object into the callers
+// autorelease pool.
+#if defined(__i386__)
+#define AUTORELEASEPOOL @autoreleasepool
+#else
+// On other platforms we rely on the remove from autorelease pool optimization.
+#define AUTORELEASEPOOL
+#endif
+
+SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
+size_t swift_stdlib_NSStringHashValue(NSString *NS_RELEASES_ARGUMENT str,
+                                      bool isASCII) {
+  AUTORELEASEPOOL {
+    return isASCII ? str.hash : str.decomposedStringWithCanonicalMapping.hash;
+  }
+}
+
+SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
+size_t
+swift_stdlib_NSStringHashValuePointer(void *opaque, bool isASCII) {
+  NSString __unsafe_unretained *str =
+      (__bridge NSString __unsafe_unretained *)opaque;
+  AUTORELEASEPOOL {
+    return isASCII ? str.hash : str.decomposedStringWithCanonicalMapping.hash;
+  }
+}
+
+SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
+NS_RETURNS_RETAINED NSString *
+swift_stdlib_NSStringLowercaseString(NSString *NS_RELEASES_ARGUMENT str) {
+  AUTORELEASEPOOL {
+    return str.lowercaseString;
+  }
+}
+
+SWIFT_CC(swift) SWIFT_RUNTIME_STDLIB_INTERFACE
+NS_RETURNS_RETAINED NSString *
+swift_stdlib_NSStringUppercaseString(NSString *NS_RELEASES_ARGUMENT str) {
+  AUTORELEASEPOOL {
+    return str.uppercaseString;
+  }
+}
+
+#endif

test/stdlib/StringMemoryTest.swift

@@ -0,0 +1,63 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift -O %s -o %t/StringMemoryTest
+// RUN: %target-run %t/StringMemoryTest | %FileCheck %s
+
+// REQUIRES: optimized_stdlib
+// REQUIRES: executable_test
+// REQUIRES: objc_interop
+
+import Foundation
+
+let str = "abcdefg\u{A758}hijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz\u{A759}"
+let str2 = "abcdefg\u{A759}hijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz\u{A758}"
+
+@inline(never)
+func lookup(_ str: String, _ dict: [String: Int]) -> Bool {
+  if let _ = dict[str] {
+    return true
+  }
+  return false
+}
+
+@inline(never)
+func uppercase(_ str: String) -> String {
+      return str.uppercased()
+}
+
+@inline(never)
+func lowercase(_ str: String) -> String {
+      return str.lowercased()
+}
+
+/// Make sure the hash function does not leak.
+
+let dict = [ "foo" : 1]
+for _ in 0 ..< 10_000_000 {
+  if lookup("\u{1F1E7}\u{1F1E7}", dict) {
+    print("Found?!")
+  }
+  if uppercase(str) == "A" {
+    print("Found?!")
+  }
+  if lowercase(str2) == "A" {
+    print("Found?!")
+  }
+}
+
+// CHECK-NOT: Found?!
+// CHECK: Not found
+
+print("Not found")
+
+var usage = rusage()
+getrusage(RUSAGE_SELF, &usage)
+
+// CHECK: success
+// CHECK-NOT: failure
+
+// We should not need 50MB for this.
+if usage.ru_maxrss > 50 * 1024 * 1024 {
+  print("failure - should not need 50MB!")
+} else {
+  print("success")
+}

test/stdlib/runtime_autorelease_optimization.txt

@@ -0,0 +1,101 @@
+// REQUIRES: objc_interop
+// RUN: otool -tvV %platform-module-dir/libswiftCore.dylib | %FileCheck %s --check-prefix=CHECK-%target-cpu
+
+// Verify the autorelease return optimization sequence.
+
+/// Test x86-64:
+
+// CHECK-x86_64-LABEL: _swift_stdlib_NSStringHashValue:
+// CHECK-x86_64-NOT: ret
+// CHECK-x86_64: movq    {{.*}}(%rip), %rsi ## Objc selector ref: decomposedStringWithCanonicalMapping
+// CHECK-x86_64: movq    {{.*}}(%rip), [[MSG:%.*]] ## Objc message: -[%rdi decomposedStringWithCanonicalMapping]
+// CHECK-x86_64: callq   *[[MSG]]
+// CHECK-x86_64: movq    %rax, %rdi
+// CHECK-x86_64: callq   {{.*}} ## symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-x86_64: ret
+
+
+// CHECK-x86_64-LABEL: _swift_stdlib_NSStringHashValuePointer:
+// CHECK-x86_64-NOT: ret
+// CHECK-x86_64: movq    {{.*}}(%rip), %rsi ## Objc selector ref: decomposedStringWithCanonicalMapping
+// CHECK-x86_64: movq    {{.*}}(%rip), [[MSG:%.*]] ## Objc message: -[%rdi decomposedStringWithCanonicalMapping]
+// CHECK-x86_64: callq   *[[MSG]]
+// CHECK-x86_64: movq    %rax, %rdi
+// CHECK-x86_64: callq   {{.*}} ## symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-x86_64: ret
+
+/// Test i386:
+
+// CHECK-i386-LABEL: _swift_stdlib_NSStringHashValue:
+// CHECK-i386-NOT: ret
+// CHECK-i386: calll   {{.*}} ## symbol stub for: _objc_msgSend
+// CHECK-i386: movl    %ebp, %ebp
+// CHECK-i386: calll   {{.*}} ## symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-i386: ret
+// CHECK-i386-LABEL: _swift_stdlib_NSStringHashValuePointer:
+// CHECK-i386-NOT: ret
+// CHECK-i386: calll   {{.*}} ## symbol stub for: _objc_msgSend
+// CHECK-i386: movl    %ebp, %ebp
+// CHECK-i386: calll   {{.*}} ## symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-i386: ret
+
+/// Test armv7:
+
+// CHECK-armv7-LABEL: _swift_stdlib_NSStringHashValue:
+// CHECK-armv7-NOT: pop {{.*}}pc{{.*}}
+// CHECK-armv7: blx     {{.*}} @ symbol stub for: _objc_msgSend
+// CHECK-armv7: mov     r7, r7
+// CHECK-armv7: blx     {{.*}} @ symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-armv7: pop {{.*}}pc{{.*}}
+// CHECK-armv7-LABEL: _swift_stdlib_NSStringHashValuePointer:
+// CHECK-armv7-NOT: pop {{.*}}pc{{.*}}
+// CHECK-armv7: blx     {{.*}} @ symbol stub for: _objc_msgSend
+// CHECK-armv7: mov     r7, r7
+// CHECK-armv7: blx     {{.*}} @ symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-armv7: pop {{.*}}pc{{.*}}
+
+/// Test armv7s:
+
+// CHECK-armv7s-LABEL: _swift_stdlib_NSStringHashValue:
+// CHECK-armv7s-NOT: pop {{.*}}pc{{.*}}
+// CHECK-armv7s: blx     {{.*}} @ symbol stub for: _objc_msgSend
+// CHECK-armv7s: mov     r7, r7
+// CHECK-armv7s: blx     {{.*}} @ symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-armv7s: pop {{.*}}pc{{.*}}
+// CHECK-armv7s-LABEL: _swift_stdlib_NSStringHashValuePointer:
+// CHECK-armv7s-NOT: pop {{.*}}pc{{.*}}
+// CHECK-armv7s: blx     {{.*}} @ symbol stub for: _objc_msgSend
+// CHECK-armv7s: mov     r7, r7
+// CHECK-armv7s: blx     {{.*}} @ symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-armv7s: pop {{.*}}pc{{.*}}
+
+
+/// Test armv7k:
+
+// CHECK-armv7k-LABEL: _swift_stdlib_NSStringHashValue:
+// CHECK-armv7k-NOT: pop {{.*}}pc{{.*}}
+// CHECK-armv7k: blx     {{.*}} @ symbol stub for: _objc_msgSend
+// CHECK-armv7k: mov     r7, r7
+// CHECK-armv7k: blx     {{.*}} @ symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-armv7k: pop {{.*}}pc{{.*}}
+// CHECK-armv7k-LABEL: _swift_stdlib_NSStringHashValuePointer:
+// CHECK-armv7k-NOT: pop {{.*}}pc{{.*}}
+// CHECK-armv7k: blx     {{.*}} @ symbol stub for: _objc_msgSend
+// CHECK-armv7k: mov     r7, r7
+// CHECK-armv7k: blx     {{.*}} @ symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-armv7k: pop {{.*}}pc{{.*}}
+
+/// Test arm64:
+
+// CHECK-arm64-LABEL: _swift_stdlib_NSStringHashValue:
+// CHECK-arm64-NOT: ret
+// CHECK-arm64: bl      {{.*}} ; Objc message: -[x0 decomposedStringWithCanonicalMapping]
+// CHECK-arm64: mov      x29, x29
+// CHECK-arm64: bl      {{.*}} ; symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-arm64: ret
+// CHECK-arm64-LABEL: _swift_stdlib_NSStringHashValuePointer:
+// CHECK-arm64-NOT: ret
+// CHECK-arm64: bl      {{.*}} ; Objc message: -[x0 decomposedStringWithCanonicalMapping]
+// CHECK-arm64: mov      x29, x29
+// CHECK-arm64: bl      {{.*}} ; symbol stub for: _objc_retainAutoreleasedReturnValue
+// CHECK-arm64: ret