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Cater for new Swift reference count representation #1525

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Merged
merged 1 commit into from
Apr 20, 2018
Merged

Cater for new Swift reference count representation #1525

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3 changes: 1 addition & 2 deletions CoreFoundation/Base.subproj/CFBase.h
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Expand Up @@ -683,8 +683,7 @@ CFTypeRef CFMakeCollectable(CFTypeRef cf) CF_AUTOMATED_REFCOUNT_UNAVAILABLE;
#if DEPLOYMENT_RUNTIME_SWIFT

#define _CF_SWIFT_RC_PINNED_FLAG 0x1
#define _CF_SWIFT_RC_FLAGS_COUNT 2
#define _CF_CONSTANT_OBJECT_STRONG_RC ((1 << _CF_SWIFT_RC_FLAGS_COUNT) | _CF_SWIFT_RC_PINNED_FLAG)
#define _CF_CONSTANT_OBJECT_STRONG_RC (_CF_SWIFT_RC_PINNED_FLAG)

#endif

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4 changes: 2 additions & 2 deletions CoreFoundation/Base.subproj/CFInternal.h
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Expand Up @@ -412,11 +412,11 @@ CF_EXPORT void *__CFConstantStringClassReference[];
#endif

#define CONST_STRING_DECL(S, V) \
const struct __CFConstStr __##S CONST_STRING_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0, 0x000007c8U}, (uint8_t *)(V), sizeof(V) - 1}; \
const struct __CFConstStr __##S CONST_STRING_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0x000007c8U}, (uint8_t *)(V), sizeof(V) - 1}; \
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Do you need to change the definition of _CF_CONSTANT_OBJECT_STRONG_RC? My guess is that the bits generated here will be wrong if you do not.

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@johnno1962 johnno1962 Apr 18, 2018 •
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This will work on little-endian only perhaps?

#if DEPLOYMENT_RUNTIME_SWIFT

#define _CF_SWIFT_RC_PINNED_FLAG 0x1
#define _CF_SWIFT_RC_FLAGS_COUNT 2
#define _CF_CONSTANT_OBJECT_STRONG_RC ((1 << _CF_SWIFT_RC_FLAGS_COUNT) | _CF_SWIFT_RC_PINNED_FLAG)

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I think the point of splitting it into strong/weak here was so we could set that pinned flag. There may now be a better way.

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@johnno1962 johnno1962 Apr 18, 2018 •
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The Android tests run through ok. Are you saying separate them again so big-endian 64 bits works?

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I don't think you were setting the pinned flag correctly before. The pinned flag is the LSB of that uintptr_t on all platforms.

I don't think you are setting the refcount correctly now. The strong refcount is stored differently on 32-bit versus 64-bit, but on all platforms it is biased: a strong refcount of 1 is represented as bit value 0.

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#define _CF_CONSTANT_OBJECT_STRONG_RC (_CF_SWIFT_RC_PINNED_FLAG) then?

const CFStringRef S = (CFStringRef)&__##S;

#define PE_CONST_STRING_DECL(S, V) \
const static struct __CFConstStr __##S CONST_STRING_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0, 0x000007c8U}, (uint8_t *)(V), sizeof(V) - 1}; \
const static struct __CFConstStr __##S CONST_STRING_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0x000007c8U}, (uint8_t *)(V), sizeof(V) - 1}; \
CF_PRIVATE const CFStringRef S = (CFStringRef)&__##S;


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2 changes: 1 addition & 1 deletion CoreFoundation/Base.subproj/CFRuntime.c
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Expand Up @@ -387,7 +387,7 @@ CFTypeRef _CFRuntimeCreateInstance(CFAllocatorRef allocator, CFTypeID typeID, CF
CFRuntimeBase *memory = (CFRuntimeBase *)swift_allocObject(isa, size, align - 1);

// Zero the rest of the memory, starting at cfinfo
memset(&memory->_cfinfoa, 0, size - (sizeof(memory->_cfisa) + sizeof(memory->_swift_strong_rc) + sizeof(memory->_swift_weak_rc)));
memset(&memory->_cfinfoa, 0, size - (sizeof(memory->_cfisa) + sizeof(memory->_swift_rc)));

// Set up the cfinfo struct
uint32_t *cfinfop = (uint32_t *)&(memory->_cfinfoa);
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5 changes: 2 additions & 3 deletions CoreFoundation/Base.subproj/CFRuntime.h
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Expand Up @@ -193,13 +193,12 @@ CF_EXPORT void _CFRuntimeUnregisterClassWithTypeID(CFTypeID typeID);
typedef struct __CFRuntimeBase {
// This matches the isa and retain count storage in Swift
uintptr_t _cfisa;
uint32_t _swift_strong_rc;
uint32_t _swift_weak_rc;
uintptr_t _swift_rc;
// This is for CF's use, and must match _NSCFType layout
_Atomic(uint64_t) _cfinfoa;
} CFRuntimeBase;

#define INIT_CFRUNTIME_BASE(...) {0, _CF_CONSTANT_OBJECT_STRONG_RC, 0, 0x0000000000000080ULL}
#define INIT_CFRUNTIME_BASE(...) {0, _CF_CONSTANT_OBJECT_STRONG_RC, 0x0000000000000080ULL}

#else

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2 changes: 1 addition & 1 deletion CoreFoundation/String.subproj/CFString.c
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Expand Up @@ -245,7 +245,7 @@ CF_INLINE void __CFStrClearHasLengthAndNullBytes(CFMutableStringRef str) {

CF_INLINE Boolean __CFStrIsConstant(CFStringRef str) {
#if DEPLOYMENT_RUNTIME_SWIFT
return str->base._swift_strong_rc & _CF_SWIFT_RC_PINNED_FLAG;
return str->base._swift_rc & _CF_SWIFT_RC_PINNED_FLAG;
#else
return __CFRuntimeIsConstant(str);
#endif
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7 changes: 3 additions & 4 deletions CoreFoundation/String.subproj/CFString.h
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Expand Up @@ -155,8 +155,7 @@ since it is the default choice with Mac OS X developer tools.
struct __CFConstStr {
struct {
uintptr_t _cfisa;
uint32_t _swift_strong_rc;
uint32_t _swift_weak_rc;
uintptr_t _swift_rc;
uint64_t _cfinfoa;
} _base;
uint8_t *_ptr;
Expand All @@ -175,12 +174,12 @@ struct __CFConstStr {

#if __BIG_ENDIAN__
#define CFSTR(cStr) ({ \
static struct __CFConstStr str CONST_STRING_LITERAL_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0, 0x00000000C8070000}, (uint8_t *)(cStr), sizeof(cStr) - 1}; \
static struct __CFConstStr str CONST_STRING_LITERAL_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0x00000000C8070000}, (uint8_t *)(cStr), sizeof(cStr) - 1}; \
(CFStringRef)&str; \
})
#else
#define CFSTR(cStr) ({ \
static struct __CFConstStr str CONST_STRING_LITERAL_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0, 0x07C8}, (uint8_t *)(cStr), sizeof(cStr) - 1}; \
static struct __CFConstStr str CONST_STRING_LITERAL_SECTION = {{(uintptr_t)&__CFConstantStringClassReference, _CF_CONSTANT_OBJECT_STRONG_RC, 0x07C8}, (uint8_t *)(cStr), sizeof(cStr) - 1}; \
(CFStringRef)&str; \
})
#endif
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9 changes: 4 additions & 5 deletions Foundation/NSCFString.swift
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Expand Up @@ -61,18 +61,17 @@ internal final class _NSCFConstantString : _NSCFString {
internal var _ptr : UnsafePointer<UInt8> {
// FIXME: Split expression as a work-around for slow type
// checking (tracked by SR-5322).
let offTemp1 = MemoryLayout<OpaquePointer>.size + MemoryLayout<Int32>.size
let offTemp2 = MemoryLayout<Int32>.size + MemoryLayout<_CFInfo>.size
let offset = offTemp1 + offTemp2
let offTemp1 = MemoryLayout<OpaquePointer>.size + MemoryLayout<uintptr_t>.size
let offset = offTemp1 + MemoryLayout<_CFInfo>.size
let ptr = Unmanaged.passUnretained(self).toOpaque()
return ptr.load(fromByteOffset: offset, as: UnsafePointer<UInt8>.self)
}

private var _lenOffset : Int {
// FIXME: Split expression as a work-around for slow type
// checking (tracked by SR-5322).
let offTemp1 = MemoryLayout<OpaquePointer>.size + MemoryLayout<Int32>.size
let offTemp2 = MemoryLayout<Int32>.size + MemoryLayout<_CFInfo>.size
let offTemp1 = MemoryLayout<OpaquePointer>.size + MemoryLayout<uintptr_t>.size
let offTemp2 = MemoryLayout<_CFInfo>.size
return offTemp1 + offTemp2 + MemoryLayout<UnsafePointer<UInt8>>.size
}

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