[stdlib] Avoid malloc_size on OpenBSD.

stdlib/public/SwiftShims/LibcShims.h

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2019 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
@@ -19,6 +19,7 @@
 #ifndef SWIFT_STDLIB_SHIMS_LIBCSHIMS_H
 #define SWIFT_STDLIB_SHIMS_LIBCSHIMS_H
 
+#include "SwiftStdbool.h"
 #include "SwiftStdint.h"
 #include "SwiftStddef.h"
 #include "Visibility.h"
@@ -104,12 +105,14 @@ static inline int _swift_stdlib_memcmp(const void *s1, const void *s2,
 
 // Non-standard extensions
 #if defined(__APPLE__)
+#define HAS_MALLOC_SIZE 1
 static inline __swift_size_t _swift_stdlib_malloc_size(const void *ptr) {
   extern __swift_size_t malloc_size(const void *);
   return malloc_size(ptr);
 }
 #elif defined(__linux__) || defined(__CYGWIN__) || defined(__ANDROID__) \
    || defined(__HAIKU__) || defined(__FreeBSD__) || defined(__wasi__)
+#define HAS_MALLOC_SIZE 1
 static inline __swift_size_t _swift_stdlib_malloc_size(const void *ptr) {
 #if defined(__ANDROID__)
 #if !defined(__ANDROID_API__) || __ANDROID_API__ >= 17
@@ -121,14 +124,23 @@ static inline __swift_size_t _swift_stdlib_malloc_size(const void *ptr) {
   return malloc_usable_size(CONST_CAST(void *, ptr));
 }
 #elif defined(_WIN32)
+#define HAS_MALLOC_SIZE 1
 static inline __swift_size_t _swift_stdlib_malloc_size(const void *ptr) {
   extern __swift_size_t _msize(void *ptr);
   return _msize(CONST_CAST(void *, ptr));
 }
 #else
-#error No malloc_size analog known for this platform/libc.
+#define HAS_MALLOC_SIZE 0
+
+static inline __swift_size_t _swift_stdlib_malloc_size(const void *ptr) {
+  return 0;
+}
 #endif
 
+static inline __swift_bool _swift_stdlib_has_malloc_size() {
+  return HAS_MALLOC_SIZE != 0;
+}
+
 // Math library functions
 static inline SWIFT_ALWAYS_INLINE
 float _stdlib_remainderf(float _self, float _other) {

stdlib/public/core/ContiguousArrayBuffer.swift

@@ -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
@@ -268,11 +268,15 @@ internal struct _ContiguousArrayBuffer<Element>: _ArrayBufferProtocol {
          realMinimumCapacity._builtinWordValue, Element.self)
 
       let storageAddr = UnsafeMutableRawPointer(Builtin.bridgeToRawPointer(_storage))
-      let endAddr = storageAddr + _swift_stdlib_malloc_size(storageAddr)
-      let realCapacity = endAddr.assumingMemoryBound(to: Element.self) - firstElementAddress
-
-      _initStorageHeader(
-        count: uninitializedCount, capacity: realCapacity)
+      if let allocSize = _mallocSize(ofAllocation: storageAddr) {
+        let endAddr = storageAddr + allocSize
+        let realCapacity = endAddr.assumingMemoryBound(to: Element.self) - firstElementAddress
+        _initStorageHeader(
+          count: uninitializedCount, capacity: realCapacity)
+      } else {
+        _initStorageHeader(
+          count: uninitializedCount, capacity: realMinimumCapacity)
+      }
     }
   }
 

stdlib/public/core/Shims.swift

@@ -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
@@ -14,9 +14,9 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#if _runtime(_ObjC)
 import SwiftShims
 
+#if _runtime(_ObjC)
 @inlinable
 internal func _makeSwiftNSFastEnumerationState()
    -> _SwiftNSFastEnumerationState {
@@ -36,3 +36,8 @@ internal var _fastEnumerationStorageMutationsTarget: CUnsignedLong = 0
 internal let _fastEnumerationStorageMutationsPtr =
   UnsafeMutablePointer<CUnsignedLong>(Builtin.addressof(&_fastEnumerationStorageMutationsTarget))
 #endif
+
+@usableFromInline @_alwaysEmitIntoClient
+internal func _mallocSize(ofAllocation ptr: UnsafeRawPointer) -> Int? {
+  return _swift_stdlib_has_malloc_size() ? _swift_stdlib_malloc_size(ptr) : nil
+}

stdlib/public/core/StringStorage.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2018 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
@@ -206,13 +206,17 @@ fileprivate func _allocate<T: AnyObject>(
   let totalTailBytes = total - numHeaderBytes
 
   let object = tailAllocator(totalTailBytes)
-  let mallocSize = _swift_stdlib_malloc_size(
-    UnsafeRawPointer(Builtin.bridgeToRawPointer(object)))
-  _internalInvariant(mallocSize % MemoryLayout<Int>.stride == 0)
+  if let allocSize = _mallocSize(ofAllocation:
+    UnsafeRawPointer(Builtin.bridgeToRawPointer(object))) {
+    _internalInvariant(allocSize % MemoryLayout<Int>.stride == 0)
 
-  let realNumTailBytes = mallocSize - numHeaderBytes
-  _internalInvariant(realNumTailBytes >= numTailBytes)
-  return (object, realNumTailBytes)
+    let realNumTailBytes = allocSize - numHeaderBytes
+    _internalInvariant(realNumTailBytes >= numTailBytes)
+
+    return (object, realNumTailBytes)
+  } else {
+    return (object, totalTailBytes)
+  }
 }
 
 fileprivate func _allocateStringStorage(