added files via upload

Tweaks/FLEX/Utility/Runtime/Objc/Reflection/FLEXIvar.m

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+//
+//  FLEXIvar.m
+//  FLEX
+//
+//  Derived from MirrorKit.
+//  Created by Tanner on 6/30/15.
+//  Copyright (c) 2020 FLEX Team. All rights reserved.
+//
+
+#import "FLEXIvar.h"
+#import "FLEXRuntimeUtility.h"
+#import "FLEXRuntimeSafety.h"
+#import "FLEXTypeEncodingParser.h"
+#import "NSString+FLEX.h"
+#include "FLEXObjcInternal.h"
+#include <dlfcn.h>
+
+@interface FLEXIvar () {
+    NSString *_flex_description;
+}
+@end
+
+@implementation FLEXIvar
+
+#pragma mark Initializers
+
++ (instancetype)ivar:(Ivar)ivar {
+    return [[self alloc] initWithIvar:ivar];
+}
+
++ (instancetype)named:(NSString *)name onClass:(Class)cls {
+    Ivar _Nullable ivar = class_getInstanceVariable(cls, name.UTF8String);
+    NSAssert(ivar, @"Cannot find ivar with name %@ on class %@", name, cls);
+    return [self ivar:ivar];
+}
+
+- (id)initWithIvar:(Ivar)ivar {
+    NSParameterAssert(ivar);
+
+    self = [super init];
+    if (self) {
+        _objc_ivar = ivar;
+        [self examine];
+    }
+
+    return self;
+}
+
+#pragma mark Other
+
+- (NSString *)description {
+    if (!_flex_description) {
+        NSString *readableType = [FLEXRuntimeUtility readableTypeForEncoding:self.typeEncoding];
+        _flex_description = [FLEXRuntimeUtility appendName:self.name toType:readableType];
+    }
+
+    return _flex_description;
+}
+
+- (NSString *)debugDescription {
+    return [NSString stringWithFormat:@"<%@ name=%@, encoding=%@, offset=%ld>",
+            NSStringFromClass(self.class), self.name, self.typeEncoding, (long)self.offset];
+}
+
+- (void)examine {
+    _name         = @(ivar_getName(self.objc_ivar) ?: "(nil)");
+    _offset       = ivar_getOffset(self.objc_ivar);
+    _typeEncoding = @(ivar_getTypeEncoding(self.objc_ivar) ?: "");
+
+    NSString *typeForDetails = _typeEncoding;
+    NSString *sizeForDetails = nil;
+    if (_typeEncoding.length) {
+        _type = (FLEXTypeEncoding)[_typeEncoding characterAtIndex:0];
+        FLEXGetSizeAndAlignment(_typeEncoding.UTF8String, &_size, nil);
+        sizeForDetails = [@(_size).stringValue stringByAppendingString:@" bytes"];
+    } else {
+        _type = FLEXTypeEncodingNull;
+        typeForDetails = @"no type info";
+        sizeForDetails = @"unknown size";
+    }
+
+    Dl_info exeInfo;
+    if (dladdr(_objc_ivar, &exeInfo)) {
+        _imagePath = exeInfo.dli_fname ? @(exeInfo.dli_fname) : nil;
+    }
+
+    _details = [NSString stringWithFormat:
+        @"%@, offset %@  —  %@",
+        sizeForDetails, @(_offset), typeForDetails
+    ];
+}
+
+- (id)getValue:(id)target {
+    id value = nil;
+    if (!FLEXIvarIsSafe(_objc_ivar) ||
+        _type == FLEXTypeEncodingNull ||
+        FLEXPointerIsTaggedPointer(target)) {
+        return nil;
+    }
+
+#ifdef __arm64__
+    // See http://www.sealiesoftware.com/blog/archive/2013/09/24/objc_explain_Non-pointer_isa.html
+    if (self.type == FLEXTypeEncodingObjcClass && [self.name isEqualToString:@"isa"]) {
+        value = object_getClass(target);
+    } else
+#endif
+    if (self.type == FLEXTypeEncodingObjcObject || self.type == FLEXTypeEncodingObjcClass) {
+        value = object_getIvar(target, self.objc_ivar);
+    } else {
+        void *pointer = (__bridge void *)target + self.offset;
+        value = [FLEXRuntimeUtility
+            valueForPrimitivePointer:pointer
+            objCType:self.typeEncoding.UTF8String
+        ];
+    }
+
+    return value;
+}
+
+- (void)setValue:(id)value onObject:(id)target {
+    const char *typeEncodingCString = self.typeEncoding.UTF8String;
+    if (self.type == FLEXTypeEncodingObjcObject) {
+        object_setIvar(target, self.objc_ivar, value);
+    } else if ([value isKindOfClass:[NSValue class]]) {
+        // Primitive - unbox the NSValue.
+        NSValue *valueValue = (NSValue *)value;
+
+        // Make sure that the box contained the correct type.
+        NSAssert(
+            strcmp(valueValue.objCType, typeEncodingCString) == 0,
+            @"Type encoding mismatch (value: %s; ivar: %s) in setting ivar named: %@ on object: %@",
+            valueValue.objCType, typeEncodingCString, self.name, target
+        );
+
+        NSUInteger bufferSize = 0;
+        if (FLEXGetSizeAndAlignment(typeEncodingCString, &bufferSize, NULL)) {
+            void *buffer = calloc(bufferSize, 1);
+            [valueValue getValue:buffer];
+            void *pointer = (__bridge void *)target + self.offset;
+            memcpy(pointer, buffer, bufferSize);
+            free(buffer);
+        }
+    }
+}
+
+- (id)getPotentiallyUnboxedValue:(id)target {
+    NSString *type = self.typeEncoding;
+    if (type.flex_typeIsNonObjcPointer && type.flex_pointeeType != FLEXTypeEncodingVoid) {
+        return [self getValue:target];
+    }
+
+    return [FLEXRuntimeUtility
+        potentiallyUnwrapBoxedPointer:[self getValue:target]
+        type:type.UTF8String
+    ];
+}
+
+@end