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Fix NSArray description (#478)
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* Run tests on different OS versions

* Fix compilation for older macOS/Xcode

* Use macOS 11 for old builds

* Fix lint for visionOS

* Fix Xcode and macOS versions in unit-tests

* Use Xcode 11 and macOS 11 for watchOS tests

* Use watchOS 7.4.0

* Fix `nsarrayCount`

* Enamble `testCopyArrayContentsMutable`

* make `nsarrayCount` nicer. Fix casting warning

* Move KSObjCApple.h to private headers

* Fix `non-void function does not return a value in all control paths`

* Fix count in array desciption

* Support `__NSSingleObjectArrayI`

* Refactor code

* Fix addresses and refactor

* Add description

* Follow the codestyle

---------

Co-authored-by: Nikolay Volosatov <code@bamx23.com>
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@GLinnik21 @bamx23
GLinnik21 and bamx23 authored May 18, 2024
1 parent c7218ad commit 1821e05
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Showing 4 changed files with 135 additions and 33 deletions.
7 changes: 5 additions & 2 deletions .swiftpm/xcode/xcshareddata/xcschemes/KSCrash-Package.xcscheme
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Original file line number Diff line number Diff line change
Expand Up @@ -135,10 +135,13 @@
Identifier = "KSDebug_Tests">
</Test>
<Test
Identifier = "KSObjC_Tests/testArrayDescription">
Identifier = "KSObjC_Tests/testDateDescription">
</Test>
<Test
Identifier = "KSObjC_Tests/testCopyArrayContentsMutable">
Identifier = "KSObjC_Tests/testDateIsValid">
</Test>
<Test
Identifier = "KSObjC_Tests/testGetDateContents">
</Test>
<Test
Identifier = "KSObjC_Tests/testDateDescription">
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138 changes: 110 additions & 28 deletions Sources/KSCrashRecordingCore/KSObjC.c
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Original file line number Diff line number Diff line change
Expand Up @@ -118,22 +118,23 @@ static int taggedStringDescription(const void* object, char* buffer, int bufferL

static ClassData g_classData[] =
{
{"__NSCFString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"NSCFString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"__NSCFConstantString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"NSCFConstantString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"__NSArray0", KSObjCClassTypeArray, ClassSubtypeNSArrayImmutable, false, arrayIsValid, arrayDescription},
{"__NSArrayI", KSObjCClassTypeArray, ClassSubtypeNSArrayImmutable, false, arrayIsValid, arrayDescription},
{"__NSArrayM", KSObjCClassTypeArray, ClassSubtypeNSArrayMutable, true, arrayIsValid, arrayDescription},
{"__NSCFArray", KSObjCClassTypeArray, ClassSubtypeCFArray, false, arrayIsValid, arrayDescription},
{"NSCFArray", KSObjCClassTypeArray, ClassSubtypeCFArray, false, arrayIsValid, arrayDescription},
{"__NSDate", KSObjCClassTypeDate, ClassSubtypeNone, false, dateIsValid, dateDescription},
{"NSDate", KSObjCClassTypeDate, ClassSubtypeNone, false, dateIsValid, dateDescription},
{"__NSCFNumber", KSObjCClassTypeNumber, ClassSubtypeNone, false, numberIsValid, numberDescription},
{"NSCFNumber", KSObjCClassTypeNumber, ClassSubtypeNone, false, numberIsValid, numberDescription},
{"NSNumber", KSObjCClassTypeNumber, ClassSubtypeNone, false, numberIsValid, numberDescription},
{"NSURL", KSObjCClassTypeURL, ClassSubtypeNone, false, urlIsValid, urlDescription},
{NULL, KSObjCClassTypeUnknown, ClassSubtypeNone, false, objectIsValid, objectDescription},
{"__NSCFString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"NSCFString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"__NSCFConstantString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"NSCFConstantString", KSObjCClassTypeString, ClassSubtypeNone, true, stringIsValid, stringDescription},
{"__NSArray0", KSObjCClassTypeArray, ClassSubtypeNSArrayImmutable, false, arrayIsValid, arrayDescription},
{"__NSArrayI", KSObjCClassTypeArray, ClassSubtypeNSArrayImmutable, false, arrayIsValid, arrayDescription},
{"__NSArrayM", KSObjCClassTypeArray, ClassSubtypeNSArrayMutable, true, arrayIsValid, arrayDescription},
{"__NSCFArray", KSObjCClassTypeArray, ClassSubtypeCFArray, false, arrayIsValid, arrayDescription},
{"__NSSingleObjectArrayI", KSObjCClassTypeArray, ClassSubtypeNSArrayImmutable, false, arrayIsValid, arrayDescription},
{"NSCFArray", KSObjCClassTypeArray, ClassSubtypeCFArray, false, arrayIsValid, arrayDescription},
{"__NSDate", KSObjCClassTypeDate, ClassSubtypeNone, false, dateIsValid, dateDescription},
{"NSDate", KSObjCClassTypeDate, ClassSubtypeNone, false, dateIsValid, dateDescription},
{"__NSCFNumber", KSObjCClassTypeNumber, ClassSubtypeNone, false, numberIsValid, numberDescription},
{"NSCFNumber", KSObjCClassTypeNumber, ClassSubtypeNone, false, numberIsValid, numberDescription},
{"NSNumber", KSObjCClassTypeNumber, ClassSubtypeNone, false, numberIsValid, numberDescription},
{"NSURL", KSObjCClassTypeURL, ClassSubtypeNone, false, urlIsValid, urlDescription},
{NULL, KSObjCClassTypeUnknown, ClassSubtypeNone, false, objectIsValid, objectDescription},
};

static ClassData g_taggedClassData[] =
Expand Down Expand Up @@ -1500,6 +1501,9 @@ static int taggedNumberDescription(const void* object, char* buffer, int bufferL
#pragma mark - NSArray -
//======================================================================

/**
* For old types
*/
struct NSArray
{
struct
Expand All @@ -1510,6 +1514,37 @@ struct NSArray
} basic;
};


/**
* @struct NSArrayDescriptor
* @brief Descriptor for new types like `__NSSingleObjectArrayI`, `__NSArrayM`, `__NSFrozenArrayM`.
*
* This structure is used to describe the internal representation of various mutable and single-object NSArray types.
* It is adapted from the LLVM `NSArrayM` descriptor to provide compatibility with different types of arrays,
* such as `__NSSingleObjectArrayI`, `__NSArrayM`, and `__NSFrozenArrayM`.
*
* @details This structure was inspired by the LLVM code found in the NSArray.cpp file:
* https://github.com/apple/llvm-project/blob/29180d27e709b76965cc02c338188e37f2df9e7f/lldb/source/Plugins/Language/ObjC/NSArray.cpp#L148-L156
* The first two fields, `_cow` (which often represents ISA) and `_data`, are also applicable for cases with
* `__NSSingleObjectArrayI`.
*
* Many older versions of Foundation have different layouts and logic for different array types. Therefore, it is
* crucial not to use these fields directly without inspecting Apple's code and making additional checks. This structure
* is used here because it fits the current needs, but if something else is required (such as implementing mutable array
* contents), it may require a different struct.
*
* @note The `packed` attribute ensures that there is no padding between the fields of the structure.
*/
typedef struct __attribute__((packed))
{
uintptr_t _cow;
uintptr_t _data;
uint32_t _offset;
uint32_t _size;
uint32_t _muts;
uint32_t _used;
} NSArrayDescriptor;

static inline bool nsarrayIsMutable(const void* const arrayPtr)
{
return getClassDataFromObject(arrayPtr)->isMutable;
Expand All @@ -1521,38 +1556,85 @@ static inline bool nsarrayIsValid(const void* const arrayPtr)
return ksmem_copySafely(arrayPtr, &temp, sizeof(temp.basic));
}

/**
* Get the count of elements in an NSArray.
*
* @note This function is based on the LLVM code in the NSArray.cpp file:
* https://github.com/apple/llvm-project/blob/29180d27e709b76965cc02c338188e37f2df9e7f/lldb/source/Plugins/Language/ObjC/NSArray.cpp#L396-L412
*/
static inline int nsarrayCount(const void* const arrayPtr)
{
const struct NSArray* array = arrayPtr;
return array->basic.count < 0 ? 0 : (int)array->basic.count;
const char* const className = ksobjc_objectClassName(arrayPtr);
bool isMutable = kCFCoreFoundationVersionNumber > 1437 && strcmp(className, "__NSArrayM") == 0;
bool isFrozen = kCFCoreFoundationVersionNumber > 1436 && strcmp(className, "__NSFrozenArrayM") == 0;

if (isMutable || isFrozen)
{
NSArrayDescriptor descriptor = { 0 };
if (ksmem_copySafely((const void*)((uintptr_t)arrayPtr + sizeof(uintptr_t)), &descriptor,
sizeof(NSArrayDescriptor)))
{
return descriptor._used;
}
}
else if (strcmp(className, "__NSSingleObjectArrayI") == 0)
{
return 1;
}
else if (strcmp(className, "__NSArray0") == 0)
{
return 0;
}
else
{
const struct NSArray* array = arrayPtr;
return (array->basic.count >= 0) ? (int)array->basic.count : 0;
}
return 0;
}

static int nsarrayContents(const void* const arrayPtr, uintptr_t* contents, int count)
{
const struct NSArray* array = arrayPtr;

if(array->basic.count < (CFIndex)count)
int actualCount = nsarrayCount(arrayPtr);
const char* const className = ksobjc_objectClassName(arrayPtr);

if (actualCount < count)
{
if(array->basic.count <= 0)
if (actualCount <= 0)
{
return 0;
}
count = (int)array->basic.count;
count = actualCount;
}
// TODO: implement this (requires bit-field unpacking) in ksobj_ivarValue
if(nsarrayIsMutable(arrayPtr))

if (nsarrayIsMutable(arrayPtr))
{
return 0;
}

if(!ksmem_copySafely(&array->basic.firstEntry, contents, (int)sizeof(*contents) * count))

const uintptr_t* entry = NULL;

if (strcmp(className, "__NSSingleObjectArrayI") == 0)
{
const NSArrayDescriptor* arrayI = (const NSArrayDescriptor*)arrayPtr;
// Using a temp variable to handle aligment of NSArrayDescriptor
uintptr_t temp_data = arrayI->_data;
entry = &temp_data;
}
else
{
const struct NSArray* array = (const struct NSArray*)arrayPtr;
entry = (const uintptr_t*)&array->basic.firstEntry;
}

if (!ksmem_copySafely(entry, contents, sizeof(*contents) * count))
{
return 0;
}

return count;
}


static inline bool cfarrayIsValid(const void* const arrayPtr)
{
struct __CFArray temp;
Expand Down
0 ...SCrashRecordingCore/include/KSObjCApple.h → Sources/KSCrashRecordingCore/KSObjCApple.h
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File renamed without changes.
23 changes: 20 additions & 3 deletions Tests/KSCrashRecordingCoreTests/KSObjC_Tests.m
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Original file line number Diff line number Diff line change
Expand Up @@ -735,7 +735,7 @@ - (void) testArrayDescriptionEmpty

- (void) testArrayDescription
{
NSArray* array = [NSArray arrayWithObjects:@"test", nil];
NSArray* array = [NSArray arrayWithObjects:@"test", nil]; // __NSSingleObjectArrayI
void* arrayPtr = (__bridge void*)array;
NSString* expectedClassName = [NSString stringWithCString:class_getName([array class]) encoding:NSUTF8StringEncoding];
NSString* expectedTheRest = @"\"test\"";
Expand All @@ -761,7 +761,7 @@ - (void) testArrayDescription

- (void) testCopyArrayContentsImmutable
{
NSArray* array = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", nil];
NSArray* array = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", nil]; // __NSArrayI
void* arrayPtr = (__bridge void*)array;
int expectedCount = (int)array.count;
int count = ksobjc_arrayCount(arrayPtr);
Expand Down Expand Up @@ -792,7 +792,7 @@ - (void) testCopyArrayContentsImmutableEmpty

- (void) testCopyArrayContentsMutable
{
NSMutableArray* array = [NSMutableArray arrayWithObjects:@"1", @"2", @"3", @"4", nil];
NSMutableArray* array = [NSMutableArray arrayWithObjects:@"1", @"2", @"3", @"4", nil]; // __NSArrayM
void* arrayPtr = (__bridge void*)array;
int expectedCount = (int)array.count;
int count = ksobjc_arrayCount(arrayPtr);
Expand All @@ -803,6 +803,23 @@ - (void) testCopyArrayContentsMutable
XCTAssertEqual(copied, expectedCopied, @"");
}

- (void) testCopyArrayContentsCopyOfMutable
{
NSMutableArray *array = [NSMutableArray array];
int size = 100;
for (NSUInteger i = 0; i < size; i++) { [array addObject:@(i)]; }

NSArray *copy = array.copy; // __NSFrozenArrayM
void* arrayPtr = (__bridge void*)copy;
int expectedCount = (int)array.count;
int count = ksobjc_arrayCount(arrayPtr);
XCTAssertEqual(count, expectedCount, @"");
uintptr_t contents[size + 10];
int copied = ksobjc_arrayContents(arrayPtr, contents, (int)sizeof(contents));
int expectedCopied = size;
XCTAssertEqual(copied, expectedCopied, @"");
}

- (void) testCopyArrayContentsMutableEmpty
{
NSMutableArray* array = [NSMutableArray array];
Expand Down

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