Add helper methods to FLEXRuntimeUtility

- Add FLEXTypeEncoding enum
- Can check whether arbitrary poiner is valid object
- Can get return type encoding for method
- Can unbox raw pointers from NSValue into actual objects, or unbox C strings into NSStrings

Code copied from the Objc runtime complies with ASPL

Classes/Utility/APPLE_LICENSE

@@ -0,0 +1,367 @@
+APPLE PUBLIC SOURCE LICENSE
+Version 2.0 - August 6, 2003
+
+Please read this License carefully before downloading this software.
+By downloading or using this software, you are agreeing to be bound by
+the terms of this License. If you do not or cannot agree to the terms
+of this License, please do not download or use the software.
+
+1. General; Definitions. This License applies to any program or other
+work which Apple Computer, Inc. ("Apple") makes publicly available and
+which contains a notice placed by Apple identifying such program or
+work as "Original Code" and stating that it is subject to the terms of
+this Apple Public Source License version 2.0 ("License"). As used in
+this License:
+
+1.1 "Applicable Patent Rights" mean: (a) in the case where Apple is
+the grantor of rights, (i) claims of patents that are now or hereafter
+acquired, owned by or assigned to Apple and (ii) that cover subject
+matter contained in the Original Code, but only to the extent
+necessary to use, reproduce and/or distribute the Original Code
+without infringement; and (b) in the case where You are the grantor of
+rights, (i) claims of patents that are now or hereafter acquired,
+owned by or assigned to You and (ii) that cover subject matter in Your
+Modifications, taken alone or in combination with Original Code.
+
+1.2 "Contributor" means any person or entity that creates or
+contributes to the creation of Modifications.
+
+1.3 "Covered Code" means the Original Code, Modifications, the
+combination of Original Code and any Modifications, and/or any
+respective portions thereof.
+
+1.4 "Externally Deploy" means: (a) to sublicense, distribute or
+otherwise make Covered Code available, directly or indirectly, to
+anyone other than You; and/or (b) to use Covered Code, alone or as
+part of a Larger Work, in any way to provide a service, including but
+not limited to delivery of content, through electronic communication
+with a client other than You.
+
+1.5 "Larger Work" means a work which combines Covered Code or portions
+thereof with code not governed by the terms of this License.
+
+1.6 "Modifications" mean any addition to, deletion from, and/or change
+to, the substance and/or structure of the Original Code, any previous
+Modifications, the combination of Original Code and any previous
+Modifications, and/or any respective portions thereof. When code is
+released as a series of files, a Modification is: (a) any addition to
+or deletion from the contents of a file containing Covered Code;
+and/or (b) any new file or other representation of computer program
+statements that contains any part of Covered Code.
+
+1.7 "Original Code" means (a) the Source Code of a program or other
+work as originally made available by Apple under this License,
+including the Source Code of any updates or upgrades to such programs
+or works made available by Apple under this License, and that has been
+expressly identified by Apple as such in the header file(s) of such
+work; and (b) the object code compiled from such Source Code and
+originally made available by Apple under this License.
+
+1.8 "Source Code" means the human readable form of a program or other
+work that is suitable for making modifications to it, including all
+modules it contains, plus any associated interface definition files,
+scripts used to control compilation and installation of an executable
+(object code).
+
+1.9 "You" or "Your" means an individual or a legal entity exercising
+rights under this License. For legal entities, "You" or "Your"
+includes any entity which controls, is controlled by, or is under
+common control with, You, where "control" means (a) the power, direct
+or indirect, to cause the direction or management of such entity,
+whether by contract or otherwise, or (b) ownership of fifty percent
+(50%) or more of the outstanding shares or beneficial ownership of
+such entity.
+
+2. Permitted Uses; Conditions & Restrictions. Subject to the terms
+and conditions of this License, Apple hereby grants You, effective on
+the date You accept this License and download the Original Code, a
+world-wide, royalty-free, non-exclusive license, to the extent of
+Apple's Applicable Patent Rights and copyrights covering the Original
+Code, to do the following:
+
+2.1 Unmodified Code. You may use, reproduce, display, perform,
+internally distribute within Your organization, and Externally Deploy
+verbatim, unmodified copies of the Original Code, for commercial or
+non-commercial purposes, provided that in each instance:
+
+(a) You must retain and reproduce in all copies of Original Code the
+copyright and other proprietary notices and disclaimers of Apple as
+they appear in the Original Code, and keep intact all notices in the
+Original Code that refer to this License; and
+
+(b) You must include a copy of this License with every copy of Source
+Code of Covered Code and documentation You distribute or Externally
+Deploy, and You may not offer or impose any terms on such Source Code
+that alter or restrict this License or the recipients' rights
+hereunder, except as permitted under Section 6.
+
+2.2 Modified Code. You may modify Covered Code and use, reproduce,
+display, perform, internally distribute within Your organization, and
+Externally Deploy Your Modifications and Covered Code, for commercial
+or non-commercial purposes, provided that in each instance You also
+meet all of these conditions:
+
+(a) You must satisfy all the conditions of Section 2.1 with respect to
+the Source Code of the Covered Code;
+
+(b) You must duplicate, to the extent it does not already exist, the
+notice in Exhibit A in each file of the Source Code of all Your
+Modifications, and cause the modified files to carry prominent notices
+stating that You changed the files and the date of any change; and
+
+(c) If You Externally Deploy Your Modifications, You must make
+Source Code of all Your Externally Deployed Modifications either
+available to those to whom You have Externally Deployed Your
+Modifications, or publicly available. Source Code of Your Externally
+Deployed Modifications must be released under the terms set forth in
+this License, including the license grants set forth in Section 3
+below, for as long as you Externally Deploy the Covered Code or twelve
+(12) months from the date of initial External Deployment, whichever is
+longer. You should preferably distribute the Source Code of Your
+Externally Deployed Modifications electronically (e.g. download from a
+web site).
+
+2.3 Distribution of Executable Versions. In addition, if You
+Externally Deploy Covered Code (Original Code and/or Modifications) in
+object code, executable form only, You must include a prominent
+notice, in the code itself as well as in related documentation,
+stating that Source Code of the Covered Code is available under the
+terms of this License with information on how and where to obtain such
+Source Code.
+
+2.4 Third Party Rights. You expressly acknowledge and agree that
+although Apple and each Contributor grants the licenses to their
+respective portions of the Covered Code set forth herein, no
+assurances are provided by Apple or any Contributor that the Covered
+Code does not infringe the patent or other intellectual property
+rights of any other entity. Apple and each Contributor disclaim any
+liability to You for claims brought by any other entity based on
+infringement of intellectual property rights or otherwise. As a
+condition to exercising the rights and licenses granted hereunder, You
+hereby assume sole responsibility to secure any other intellectual
+property rights needed, if any. For example, if a third party patent
+license is required to allow You to distribute the Covered Code, it is
+Your responsibility to acquire that license before distributing the
+Covered Code.
+
+3. Your Grants. In consideration of, and as a condition to, the
+licenses granted to You under this License, You hereby grant to any
+person or entity receiving or distributing Covered Code under this
+License a non-exclusive, royalty-free, perpetual, irrevocable license,
+under Your Applicable Patent Rights and other intellectual property
+rights (other than patent) owned or controlled by You, to use,
+reproduce, display, perform, modify, sublicense, distribute and
+Externally Deploy Your Modifications of the same scope and extent as
+Apple's licenses under Sections 2.1 and 2.2 above.
+
+4. Larger Works. You may create a Larger Work by combining Covered
+Code with other code not governed by the terms of this License and
+distribute the Larger Work as a single product. In each such instance,
+You must make sure the requirements of this License are fulfilled for
+the Covered Code or any portion thereof.
+
+5. Limitations on Patent License. Except as expressly stated in
+Section 2, no other patent rights, express or implied, are granted by
+Apple herein. Modifications and/or Larger Works may require additional
+patent licenses from Apple which Apple may grant in its sole
+discretion.
+
+6. Additional Terms. You may choose to offer, and to charge a fee for,
+warranty, support, indemnity or liability obligations and/or other
+rights consistent with the scope of the license granted herein
+("Additional Terms") to one or more recipients of Covered Code.
+However, You may do so only on Your own behalf and as Your sole
+responsibility, and not on behalf of Apple or any Contributor. You
+must obtain the recipient's agreement that any such Additional Terms
+are offered by You alone, and You hereby agree to indemnify, defend
+and hold Apple and every Contributor harmless for any liability
+incurred by or claims asserted against Apple or such Contributor by
+reason of any such Additional Terms.
+
+7. Versions of the License. Apple may publish revised and/or new
+versions of this License from time to time. Each version will be given
+a distinguishing version number. Once Original Code has been published
+under a particular version of this License, You may continue to use it
+under the terms of that version. You may also choose to use such
+Original Code under the terms of any subsequent version of this
+License published by Apple. No one other than Apple has the right to
+modify the terms applicable to Covered Code created under this
+License.
+
+8. NO WARRANTY OR SUPPORT. The Covered Code may contain in whole or in
+part pre-release, untested, or not fully tested works. The Covered
+Code may contain errors that could cause failures or loss of data, and
+may be incomplete or contain inaccuracies. You expressly acknowledge
+and agree that use of the Covered Code, or any portion thereof, is at
+Your sole and entire risk. THE COVERED CODE IS PROVIDED "AS IS" AND
+WITHOUT WARRANTY, UPGRADES OR SUPPORT OF ANY KIND AND APPLE AND
+APPLE'S LICENSOR(S) (COLLECTIVELY REFERRED TO AS "APPLE" FOR THE
+PURPOSES OF SECTIONS 8 AND 9) AND ALL CONTRIBUTORS EXPRESSLY DISCLAIM
+ALL WARRANTIES AND/OR CONDITIONS, EXPRESS OR IMPLIED, INCLUDING, BUT
+NOT LIMITED TO, THE IMPLIED WARRANTIES AND/OR CONDITIONS OF
+MERCHANTABILITY, OF SATISFACTORY QUALITY, OF FITNESS FOR A PARTICULAR
+PURPOSE, OF ACCURACY, OF QUIET ENJOYMENT, AND NONINFRINGEMENT OF THIRD
+PARTY RIGHTS. APPLE AND EACH CONTRIBUTOR DOES NOT WARRANT AGAINST
+INTERFERENCE WITH YOUR ENJOYMENT OF THE COVERED CODE, THAT THE
+FUNCTIONS CONTAINED IN THE COVERED CODE WILL MEET YOUR REQUIREMENTS,
+THAT THE OPERATION OF THE COVERED CODE WILL BE UNINTERRUPTED OR
+ERROR-FREE, OR THAT DEFECTS IN THE COVERED CODE WILL BE CORRECTED. NO
+ORAL OR WRITTEN INFORMATION OR ADVICE GIVEN BY APPLE, AN APPLE
+AUTHORIZED REPRESENTATIVE OR ANY CONTRIBUTOR SHALL CREATE A WARRANTY.
+You acknowledge that the Covered Code is not intended for use in the
+operation of nuclear facilities, aircraft navigation, communication
+systems, or air traffic control machines in which case the failure of
+the Covered Code could lead to death, personal injury, or severe
+physical or environmental damage.
+
+9. LIMITATION OF LIABILITY. TO THE EXTENT NOT PROHIBITED BY LAW, IN NO
+EVENT SHALL APPLE OR ANY CONTRIBUTOR BE LIABLE FOR ANY INCIDENTAL,
+SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES ARISING OUT OF OR RELATING
+TO THIS LICENSE OR YOUR USE OR INABILITY TO USE THE COVERED CODE, OR
+ANY PORTION THEREOF, WHETHER UNDER A THEORY OF CONTRACT, WARRANTY,
+TORT (INCLUDING NEGLIGENCE), PRODUCTS LIABILITY OR OTHERWISE, EVEN IF
+APPLE OR SUCH CONTRIBUTOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+DAMAGES AND NOTWITHSTANDING THE FAILURE OF ESSENTIAL PURPOSE OF ANY
+REMEDY. SOME JURISDICTIONS DO NOT ALLOW THE LIMITATION OF LIABILITY OF
+INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THIS LIMITATION MAY NOT APPLY
+TO YOU. In no event shall Apple's total liability to You for all
+damages (other than as may be required by applicable law) under this
+License exceed the amount of fifty dollars ($50.00).
+
+10. Trademarks. This License does not grant any rights to use the
+trademarks or trade names "Apple", "Apple Computer", "Mac", "Mac OS",
+"QuickTime", "QuickTime Streaming Server" or any other trademarks,
+service marks, logos or trade names belonging to Apple (collectively
+"Apple Marks") or to any trademark, service mark, logo or trade name
+belonging to any Contributor. You agree not to use any Apple Marks in
+or as part of the name of products derived from the Original Code or
+to endorse or promote products derived from the Original Code other
+than as expressly permitted by and in strict compliance at all times
+with Apple's third party trademark usage guidelines which are posted
+at http://www.apple.com/legal/guidelinesfor3rdparties.html.
+
+11. Ownership. Subject to the licenses granted under this License,
+each Contributor retains all rights, title and interest in and to any
+Modifications made by such Contributor. Apple retains all rights,
+title and interest in and to the Original Code and any Modifications
+made by or on behalf of Apple ("Apple Modifications"), and such Apple
+Modifications will not be automatically subject to this License. Apple
+may, at its sole discretion, choose to license such Apple
+Modifications under this License, or on different terms from those
+contained in this License or may choose not to license them at all.
+
+12. Termination.
+
+12.1 Termination. This License and the rights granted hereunder will
+terminate:
+
+(a) automatically without notice from Apple if You fail to comply with
+any term(s) of this License and fail to cure such breach within 30
+days of becoming aware of such breach;
+
+(b) immediately in the event of the circumstances described in Section
+13.5(b); or
+
+(c) automatically without notice from Apple if You, at any time during
+the term of this License, commence an action for patent infringement
+against Apple; provided that Apple did not first commence
+an action for patent infringement against You in that instance.
+
+12.2 Effect of Termination. Upon termination, You agree to immediately
+stop any further use, reproduction, modification, sublicensing and
+distribution of the Covered Code. All sublicenses to the Covered Code
+which have been properly granted prior to termination shall survive
+any termination of this License. Provisions which, by their nature,
+should remain in effect beyond the termination of this License shall
+survive, including but not limited to Sections 3, 5, 8, 9, 10, 11,
+12.2 and 13. No party will be liable to any other for compensation,
+indemnity or damages of any sort solely as a result of terminating
+this License in accordance with its terms, and termination of this
+License will be without prejudice to any other right or remedy of
+any party.
+
+13. Miscellaneous.
+
+13.1 Government End Users. The Covered Code is a "commercial item" as
+defined in FAR 2.101. Government software and technical data rights in
+the Covered Code include only those rights customarily provided to the
+public as defined in this License. This customary commercial license
+in technical data and software is provided in accordance with FAR
+12.211 (Technical Data) and 12.212 (Computer Software) and, for
+Department of Defense purchases, DFAR 252.227-7015 (Technical Data --
+Commercial Items) and 227.7202-3 (Rights in Commercial Computer
+Software or Computer Software Documentation). Accordingly, all U.S.
+Government End Users acquire Covered Code with only those rights set
+forth herein.
+
+13.2 Relationship of Parties. This License will not be construed as
+creating an agency, partnership, joint venture or any other form of
+legal association between or among You, Apple or any Contributor, and
+You will not represent to the contrary, whether expressly, by
+implication, appearance or otherwise.
+
+13.3 Independent Development. Nothing in this License will impair
+Apple's right to acquire, license, develop, have others develop for
+it, market and/or distribute technology or products that perform the
+same or similar functions as, or otherwise compete with,
+Modifications, Larger Works, technology or products that You may
+develop, produce, market or distribute.
+
+13.4 Waiver; Construction. Failure by Apple or any Contributor to
+enforce any provision of this License will not be deemed a waiver of
+future enforcement of that or any other provision. Any law or
+regulation which provides that the language of a contract shall be
+construed against the drafter will not apply to this License.
+
+13.5 Severability. (a) If for any reason a court of competent
+jurisdiction finds any provision of this License, or portion thereof,
+to be unenforceable, that provision of the License will be enforced to
+the maximum extent permissible so as to effect the economic benefits
+and intent of the parties, and the remainder of this License will
+continue in full force and effect. (b) Notwithstanding the foregoing,
+if applicable law prohibits or restricts You from fully and/or
+specifically complying with Sections 2 and/or 3 or prevents the
+enforceability of either of those Sections, this License will
+immediately terminate and You must immediately discontinue any use of
+the Covered Code and destroy all copies of it that are in your
+possession or control.
+
+13.6 Dispute Resolution. Any litigation or other dispute resolution
+between You and Apple relating to this License shall take place in the
+Northern District of California, and You and Apple hereby consent to
+the personal jurisdiction of, and venue in, the state and federal
+courts within that District with respect to this License. The
+application of the United Nations Convention on Contracts for the
+International Sale of Goods is expressly excluded.
+
+13.7 Entire Agreement; Governing Law. This License constitutes the
+entire agreement between the parties with respect to the subject
+matter hereof. This License shall be governed by the laws of the
+United States and the State of California, except that body of
+California law concerning conflicts of law.
+
+Where You are located in the province of Quebec, Canada, the following
+clause applies: The parties hereby confirm that they have requested
+that this License and all related documents be drafted in English. Les
+parties ont exige que le present contrat et tous les documents
+connexes soient rediges en anglais.
+
+EXHIBIT A.
+
+"Portions Copyright (c) 1999-2003 Apple Computer, Inc. All Rights
+Reserved.
+
+This file contains Original Code and/or Modifications of Original Code
+as defined in and that are subject to the Apple Public Source License
+Version 2.0 (the 'License'). You may not use this file except in
+compliance with the License. Please obtain a copy of the License at
+http://www.opensource.apple.com/apsl/ and read it before using this
+file.
+
+The Original Code and all software distributed under the License are
+distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+Please see the License for the specific language governing rights and
+limitations under the License."

Classes/Utility/FLEXObjcInternal.h

@@ -0,0 +1,23 @@
+//
+//  FLEXObjcInternal.h
+//  FLEX
+//
+//  Created by Tanner Bennett on 11/1/18.
+//
+
+#import <Foundation/Foundation.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/// @brief Assumes memory is valid and readable.
+/// @discussion objc-internal.h, objc-private.h, and objc-config.h
+/// https://blog.timac.org/2016/1124-testing-if-an-arbitrary-pointer-is-a-valid-objective-c-object/
+/// http://llvm.org/svn/llvm-project/lldb/trunk/examples/summaries/cocoa/objc_runtime.py
+/// https://blog.timac.org/2016/1124-testing-if-an-arbitrary-pointer-is-a-valid-objective-c-object/
+BOOL FLEXPointerIsValidObjcObject(const void * ptr);
+
+#ifdef __cplusplus
+}
+#endif

Classes/Utility/FLEXObjcInternal.mm

@@ -0,0 +1,309 @@
+//
+//  FLEXObjcInternal.mm
+//  FLEX
+//
+//  Created by Tanner Bennett on 11/1/18.
+//
+
+/*
+ * Copyright (c) 2005-2007 Apple Inc.  All Rights Reserved.
+ * 
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#import "FLEXObjcInternal.h"
+#import <objc/runtime.h>
+#import <malloc/malloc.h>
+
+#define ALWAYS_INLINE inline __attribute__((always_inline))
+#define NEVER_INLINE inline __attribute__((noinline))
+
+// The macros below are copied straight from
+// objc-internal.h, objc-private.h, objc-object.h, and objc-config.h with
+// as few modifications as possible. Changes are noted in boxed comments.
+// https://opensource.apple.com/source/objc4/objc4-723/
+// https://opensource.apple.com/source/objc4/objc4-723/runtime/objc-internal.h.auto.html
+// https://opensource.apple.com/source/objc4/objc4-723/runtime/objc-private.h.auto.html
+// https://opensource.apple.com/source/objc4/objc4-723/runtime/objc-config.h.auto.html
+// https://opensource.apple.com/source/objc4/objc4-723/runtime/objc-object.h.auto.html
+
+/////////////////////
+// objc-internal.h //
+/////////////////////
+
+#if TARGET_OS_OSX && __x86_64__
+// 64-bit Mac - tag bit is LSB
+#   define OBJC_MSB_TAGGED_POINTERS 0
+#else
+// Everything else - tag bit is MSB
+#   define OBJC_MSB_TAGGED_POINTERS 1
+#endif
+
+#define _OBJC_TAG_INDEX_MASK 0x7
+// array slot includes the tag bit itself
+#define _OBJC_TAG_SLOT_COUNT 16
+#define _OBJC_TAG_SLOT_MASK 0xf
+
+#define _OBJC_TAG_EXT_INDEX_MASK 0xff
+// array slot has no extra bits
+#define _OBJC_TAG_EXT_SLOT_COUNT 256
+#define _OBJC_TAG_EXT_SLOT_MASK 0xff
+
+#if OBJC_MSB_TAGGED_POINTERS
+#   define _OBJC_TAG_MASK (1UL<<63)
+#   define _OBJC_TAG_INDEX_SHIFT 60
+#   define _OBJC_TAG_SLOT_SHIFT 60
+#   define _OBJC_TAG_PAYLOAD_LSHIFT 4
+#   define _OBJC_TAG_PAYLOAD_RSHIFT 4
+#   define _OBJC_TAG_EXT_MASK (0xfUL<<60)
+#   define _OBJC_TAG_EXT_INDEX_SHIFT 52
+#   define _OBJC_TAG_EXT_SLOT_SHIFT 52
+#   define _OBJC_TAG_EXT_PAYLOAD_LSHIFT 12
+#   define _OBJC_TAG_EXT_PAYLOAD_RSHIFT 12
+#else
+#   define _OBJC_TAG_MASK 1UL
+#   define _OBJC_TAG_INDEX_SHIFT 1
+#   define _OBJC_TAG_SLOT_SHIFT 0
+#   define _OBJC_TAG_PAYLOAD_LSHIFT 0
+#   define _OBJC_TAG_PAYLOAD_RSHIFT 4
+#   define _OBJC_TAG_EXT_MASK 0xfUL
+#   define _OBJC_TAG_EXT_INDEX_SHIFT 4
+#   define _OBJC_TAG_EXT_SLOT_SHIFT 4
+#   define _OBJC_TAG_EXT_PAYLOAD_LSHIFT 0
+#   define _OBJC_TAG_EXT_PAYLOAD_RSHIFT 12
+#endif
+
+//////////////////////////////////////
+// originally _objc_isTaggedPointer //
+//////////////////////////////////////
+static BOOL flex_isTaggedPointer(const void *ptr) 
+{
+    return ((uintptr_t)ptr & _OBJC_TAG_MASK) == _OBJC_TAG_MASK;
+}
+
+///////////////////
+// objc-config.h //
+///////////////////
+
+// Define SUPPORT_INDEXED_ISA=1 on platforms that store the class in the isa 
+// field as an index into a class table.
+#if __ARM_ARCH_7K__ >= 2
+#   define SUPPORT_INDEXED_ISA 1
+#else
+#   define SUPPORT_INDEXED_ISA 0
+#endif
+
+// Define SUPPORT_PACKED_ISA=1 on platforms that store the class in the isa 
+// field as a maskable pointer with other data around it.
+#if (!__LP64__  ||  TARGET_OS_WIN32  ||  TARGET_OS_SIMULATOR)
+#   define SUPPORT_PACKED_ISA 0
+#else
+#   define SUPPORT_PACKED_ISA 1
+#endif
+
+// Define SUPPORT_NONPOINTER_ISA=1 on any platform that may store something
+// in the isa field that is not a raw pointer.
+#if !SUPPORT_INDEXED_ISA  &&  !SUPPORT_PACKED_ISA
+#   define SUPPORT_NONPOINTER_ISA 0
+#else
+#   define SUPPORT_NONPOINTER_ISA 1
+#endif
+
+////////////////////
+// objc-private.h //
+////////////////////
+
+union isa_t 
+{
+    isa_t() { }
+    isa_t(uintptr_t value) : bits(value) { }
+    
+    Class cls;
+    uintptr_t bits;
+    
+#if SUPPORT_PACKED_ISA
+    
+    // extra_rc must be the MSB-most field (so it matches carry/overflow flags)
+    // nonpointer must be the LSB (fixme or get rid of it)
+    // shiftcls must occupy the same bits that a real class pointer would
+    // bits + RC_ONE is equivalent to extra_rc + 1
+    // RC_HALF is the high bit of extra_rc (i.e. half of its range)
+    
+    // future expansion:
+    // uintptr_t fast_rr : 1;     // no r/r overrides
+    // uintptr_t lock : 2;        // lock for atomic property, @synch
+    // uintptr_t extraBytes : 1;  // allocated with extra bytes
+    
+# if __arm64__
+#   define ISA_MASK        0x0000000ffffffff8ULL
+#   define ISA_MAGIC_MASK  0x000003f000000001ULL
+#   define ISA_MAGIC_VALUE 0x000001a000000001ULL
+    struct {
+        uintptr_t nonpointer        : 1;
+        uintptr_t has_assoc         : 1;
+        uintptr_t has_cxx_dtor      : 1;
+        uintptr_t shiftcls          : 33; // MACH_VM_MAX_ADDRESS 0x1000000000
+        uintptr_t magic             : 6;
+        uintptr_t weakly_referenced : 1;
+        uintptr_t deallocating      : 1;
+        uintptr_t has_sidetable_rc  : 1;
+        uintptr_t extra_rc          : 19;
+#       define RC_ONE   (1ULL<<45)
+#       define RC_HALF  (1ULL<<18)
+    };
+    
+# elif __x86_64__
+#   define ISA_MASK        0x00007ffffffffff8ULL
+#   define ISA_MAGIC_MASK  0x001f800000000001ULL
+#   define ISA_MAGIC_VALUE 0x001d800000000001ULL
+    struct {
+        uintptr_t nonpointer        : 1;
+        uintptr_t has_assoc         : 1;
+        uintptr_t has_cxx_dtor      : 1;
+        uintptr_t shiftcls          : 44; // MACH_VM_MAX_ADDRESS 0x7fffffe00000
+        uintptr_t magic             : 6;
+        uintptr_t weakly_referenced : 1;
+        uintptr_t deallocating      : 1;
+        uintptr_t has_sidetable_rc  : 1;
+        uintptr_t extra_rc          : 8;
+#       define RC_ONE   (1ULL<<56)
+#       define RC_HALF  (1ULL<<7)
+    };
+    
+# else
+#   error unknown architecture for packed isa
+# endif
+    
+    // SUPPORT_PACKED_ISA
+#endif
+    
+    
+#if SUPPORT_INDEXED_ISA
+    
+# if  __ARM_ARCH_7K__ >= 2
+    
+#   define ISA_INDEX_IS_NPI      1
+#   define ISA_INDEX_MASK        0x0001FFFC
+#   define ISA_INDEX_SHIFT       2
+#   define ISA_INDEX_BITS        15
+#   define ISA_INDEX_COUNT       (1 << ISA_INDEX_BITS)
+#   define ISA_INDEX_MAGIC_MASK  0x001E0001
+#   define ISA_INDEX_MAGIC_VALUE 0x001C0001
+    struct {
+        uintptr_t nonpointer        : 1;
+        uintptr_t has_assoc         : 1;
+        uintptr_t indexcls          : 15;
+        uintptr_t magic             : 4;
+        uintptr_t has_cxx_dtor      : 1;
+        uintptr_t weakly_referenced : 1;
+        uintptr_t deallocating      : 1;
+        uintptr_t has_sidetable_rc  : 1;
+        uintptr_t extra_rc          : 7;
+#       define RC_ONE   (1ULL<<25)
+#       define RC_HALF  (1ULL<<6)
+    };
+    
+# else
+#   error unknown architecture for indexed isa
+# endif
+    
+    // SUPPORT_INDEXED_ISA
+#endif
+    
+};
+
+///////////////////
+// objc-object.h //
+///////////////////
+
+////////////////////////////////////////////////
+// originally objc_object::isExtTaggedPointer //
+////////////////////////////////////////////////
+static BOOL flex_isExtTaggedPointer(const void *ptr) 
+{
+    return ((uintptr_t)ptr & _OBJC_TAG_EXT_MASK) == _OBJC_TAG_EXT_MASK;
+}
+
+struct flex_objc_object {
+    isa_t isa;
+};
+
+//////////////////////////////////////////////////////////
+// Returns nil on platforms without nonpointer isa.     //
+// Supporting those platforms would be too complicated  //
+// for such a niche feature anyway. - @NSExceptional    //
+//                                                      //
+// Code modified from objc_object::ISA() on 11/04/18    //
+//////////////////////////////////////////////////////////
+static id flex_getIsa(const flex_objc_object *object) {
+#if SUPPORT_NONPOINTER_ISA
+    if (object->isa.nonpointer) {
+        return object_getClass((__bridge id)object);
+    }
+    return (__bridge Class)(void *)object->isa.bits;
+#else
+    return nil;
+#endif
+}
+
+/////////////////////////////////////
+// FLEXObjectInternal              //
+// No Apple code beyond this point //
+/////////////////////////////////////
+
+extern "C" {
+/// Assumes memory is valid and readable.
+/// https://blog.timac.org/2016/1124-testing-if-an-arbitrary-pointer-is-a-valid-objective-c-object/
+BOOL FLEXPointerIsValidObjcObject(const void * ptr)
+{
+    uintptr_t pointer = (uintptr_t)ptr;
+    
+    if (!ptr) {
+        return NO;
+    }
+    
+    // Tagged pointers have 0x1 set, no other valid pointers do
+    // objc-internal.h -> _objc_isTaggedPointer()
+    if (flex_isTaggedPointer(ptr) || flex_isExtTaggedPointer(ptr)) {
+        return YES;
+    }
+    
+    // Check pointer alignment
+    if ((pointer % sizeof(uintptr_t)) != 0) {
+        return NO;
+    }
+    
+    // From LLDB:
+    // Pointers in a class_t will only have bits 0 through 46 set,
+    // so if any pointer has bits 47 through 63 high, we know that this is not a valid isa
+    // http://llvm.org/svn/llvm-project/lldb/trunk/examples/summaries/cocoa/objc_runtime.py
+    if ((pointer & 0xFFFF800000000000) != 0) {
+        return NO;
+    }
+    
+    // http://www.sealiesoftware.com/blog/archive/2013/09/24/objc_explain_Non-pointer_isa.html :
+    if (flex_getIsa((const flex_objc_object *)ptr)) {
+        return YES;
+    }
+    
+    return NO;
+}
+    
+}

Classes/Utility/FLEXRuntimeUtility.h

@@ -25,10 +25,44 @@ extern NSString *const kFLEXUtilityAttributeWeak;
 extern NSString *const kFLEXUtilityAttributeGarbageCollectable;
 extern NSString *const kFLEXUtilityAttributeOldStyleTypeEncoding;
 
+typedef NS_ENUM(char, FLEXTypeEncoding)
+{
+    FLEXTypeEncodingUnknown          = '?',
+    FLEXTypeEncodingChar             = 'c',
+    FLEXTypeEncodingInt              = 'i',
+    FLEXTypeEncodingShort            = 's',
+    FLEXTypeEncodingLong             = 'l',
+    FLEXTypeEncodingLongLong         = 'q',
+    FLEXTypeEncodingUnsignedChar     = 'C',
+    FLEXTypeEncodingUnsignedInt      = 'I',
+    FLEXTypeEncodingUnsignedShort    = 'S',
+    FLEXTypeEncodingUnsignedLong     = 'L',
+    FLEXTypeEncodingUnsignedLongLong = 'Q',
+    FLEXTypeEncodingFloat            = 'f',
+    FLEXTypeEncodingDouble           = 'd',
+    FLEXTypeEncodingCBool            = 'B',
+    FLEXTypeEncodingVoid             = 'v',
+    FLEXTypeEncodingCString          = '*',
+    FLEXTypeEncodingObjcObject       = '@',
+    FLEXTypeEncodingObjcClass        = '#',
+    FLEXTypeEncodingSelector         = ':',
+    FLEXTypeEncodingArray            = '[',
+    FLEXTypeEncodingStruct           = '{',
+    FLEXTypeEncodingUnion            = '(',
+    FLEXTypeEncodingBitField         = 'b',
+    FLEXTypeEncodingPointer          = '^',
+    FLEXTypeEncodingConst            = 'r'
+};
+
 #define FLEXEncodeClass(class) ("@\"" #class "\"")
 
 @interface FLEXRuntimeUtility : NSObject
 
+// General Helpers
++ (BOOL)pointerIsValidObjcObject:(const void *)pointer;
+/// Unwraps raw pointers to objects stored in NSValue, and re-boxes C strings into NSStrings.
++ (id)potentiallyUnwrapBoxedPointer:(id)returnedObjectOrNil type:(const FLEXTypeEncoding *)returnType;
+
 // Property Helpers
 + (NSString *)prettyNameForProperty:(objc_property_t)property;
 + (NSString *)typeEncodingForProperty:(objc_property_t)property;
@@ -47,6 +81,7 @@ extern NSString *const kFLEXUtilityAttributeOldStyleTypeEncoding;
 // Method Helpers
 + (NSString *)prettyNameForMethod:(Method)method isClassMethod:(BOOL)isClassMethod;
 + (NSArray *)prettyArgumentComponentsForMethod:(Method)method;
++ (FLEXTypeEncoding *)returnTypeForMethod:(Method)method;
 
 // Method Calling/Field Editing
 + (id)performSelector:(SEL)selector onObject:(id)object withArguments:(NSArray *)arguments error:(NSError * __autoreleasing *)error;

Classes/Utility/FLEXRuntimeUtility.m

@@ -8,6 +8,7 @@
 
 #import <UIKit/UIKit.h>
 #import "FLEXRuntimeUtility.h"
+#import "FLEXObjcInternal.h"
 
 // See https://developer.apple.com/library/ios/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtPropertyIntrospection.html#//apple_ref/doc/uid/TP40008048-CH101-SW6
 NSString *const kFLEXUtilityAttributeTypeEncoding = @"T";
@@ -36,6 +37,57 @@ const unsigned int kFLEXNumberOfImplicitArgs = 2;
 @implementation FLEXRuntimeUtility
 
 
+#pragma mark - General Helpers (Public)
+
++ (BOOL)pointerIsValidObjcObject:(const void *)pointer
+{
+    return FLEXPointerIsValidObjcObject(pointer);
+}
+
++ (id)potentiallyUnwrapBoxedPointer:(id)returnedObjectOrNil type:(const FLEXTypeEncoding *)returnType
+{
+    if (!returnedObjectOrNil) {
+        return nil;
+    }
+    
+    NSInteger i = 0;
+    if (returnType[i] == FLEXTypeEncodingConst) {
+        i++;
+    }
+    
+    BOOL returnsObjectOrClass = returnType[i] == FLEXTypeEncodingObjcObject ||
+                                returnType[i] == FLEXTypeEncodingObjcClass;
+    BOOL returnsVoidPointer   = returnType[i] == FLEXTypeEncodingPointer &&
+                                returnType[i+1] == FLEXTypeEncodingVoid;
+    BOOL returnsCString       = returnType[i] == FLEXTypeEncodingCString;
+    
+    // If we got back an NSValue and the return type is not an object,
+    // we check to see if the pointer is of a valid object. If not,
+    // we just display the NSValue.
+    if (!returnsObjectOrClass) {
+        // Can only be NSValue since return type is not an object,
+        // so we bail if this doesn't add up
+        if (![returnedObjectOrNil isKindOfClass:[NSValue class]]) {
+            return returnedObjectOrNil;
+        }
+        
+        NSValue *value = (NSValue *)returnedObjectOrNil;
+        
+        if (returnsCString) {
+            // Wrap char * in NSString
+            const char *string = (const char *)value.pointerValue;
+            returnedObjectOrNil = [NSString stringWithCString:string encoding:NSUTF8StringEncoding];
+        } else if (returnsVoidPointer) {
+            // Cast valid objects disguised as void * to id
+            if ([FLEXRuntimeUtility pointerIsValidObjcObject:value.pointerValue]) {
+                returnedObjectOrNil = (__bridge id)value.pointerValue;
+            }
+        }
+    }
+    
+    return returnedObjectOrNil;
+}
+
 #pragma mark - Property Helpers (Public)
 
 + (NSString *)prettyNameForProperty:(objc_property_t)property
@@ -303,6 +355,11 @@ const unsigned int kFLEXNumberOfImplicitArgs = 2;
     return components;
 }
 
++ (FLEXTypeEncoding *)returnTypeForMethod:(Method)method
+{
+    return (FLEXTypeEncoding *)method_copyReturnType(method);
+}
+
 
 #pragma mark - Method Calling/Field Editing (Public)
 

FLEX.xcodeproj/project.pbxproj

@@ -166,6 +166,8 @@
 		94AAF0381BAF2E1F00DE8760 /* FLEXKeyboardHelpViewController.h in Headers */ = {isa = PBXBuildFile; fileRef = 94AAF0361BAF2E1F00DE8760 /* FLEXKeyboardHelpViewController.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		94AAF0391BAF2E1F00DE8760 /* FLEXKeyboardHelpViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = 94AAF0371BAF2E1F00DE8760 /* FLEXKeyboardHelpViewController.m */; };
 		94AAF03A1BAF2F0300DE8760 /* FLEXKeyboardShortcutManager.h in Headers */ = {isa = PBXBuildFile; fileRef = 942DCD821BAE0AD300DB5DC2 /* FLEXKeyboardShortcutManager.h */; settings = {ATTRIBUTES = (Private, ); }; };
+		C37A0C93218BAC9600848CA7 /* FLEXObjcInternal.h in Headers */ = {isa = PBXBuildFile; fileRef = C37A0C91218BAC9600848CA7 /* FLEXObjcInternal.h */; };
+		C37A0C94218BAC9600848CA7 /* FLEXObjcInternal.mm in Sources */ = {isa = PBXBuildFile; fileRef = C37A0C92218BAC9600848CA7 /* FLEXObjcInternal.mm */; };
 		C395D6D921789BD800BEAD4D /* FLEXColorExplorerViewController.h in Headers */ = {isa = PBXBuildFile; fileRef = C395D6D721789BD800BEAD4D /* FLEXColorExplorerViewController.h */; };
 		C395D6DA21789BD800BEAD4D /* FLEXColorExplorerViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = C395D6D821789BD800BEAD4D /* FLEXColorExplorerViewController.m */; };
 		C3DA55FE21A76406005DDA60 /* FLEXMutableFieldEditorViewController.h in Headers */ = {isa = PBXBuildFile; fileRef = C3DA55FC21A76406005DDA60 /* FLEXMutableFieldEditorViewController.h */; };
@@ -348,6 +350,8 @@
 		94A515241C4CA2080063292F /* FLEXToolbarItem.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = FLEXToolbarItem.m; path = Classes/Toolbar/FLEXToolbarItem.m; sourceTree = SOURCE_ROOT; };
 		94AAF0361BAF2E1F00DE8760 /* FLEXKeyboardHelpViewController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = FLEXKeyboardHelpViewController.h; sourceTree = "<group>"; };
 		94AAF0371BAF2E1F00DE8760 /* FLEXKeyboardHelpViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FLEXKeyboardHelpViewController.m; sourceTree = "<group>"; };
+		C37A0C91218BAC9600848CA7 /* FLEXObjcInternal.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FLEXObjcInternal.h; sourceTree = "<group>"; };
+		C37A0C92218BAC9600848CA7 /* FLEXObjcInternal.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = FLEXObjcInternal.mm; sourceTree = "<group>"; };
 		C395D6D721789BD800BEAD4D /* FLEXColorExplorerViewController.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FLEXColorExplorerViewController.h; sourceTree = "<group>"; };
 		C395D6D821789BD800BEAD4D /* FLEXColorExplorerViewController.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = FLEXColorExplorerViewController.m; sourceTree = "<group>"; };
 		C3DA55FC21A76406005DDA60 /* FLEXMutableFieldEditorViewController.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FLEXMutableFieldEditorViewController.h; sourceTree = "<group>"; };
@@ -475,6 +479,8 @@
 				3A4C94581B5B21410088C3F2 /* FLEXMultilineTableViewCell.m */,
 				3A4C94591B5B21410088C3F2 /* FLEXResources.h */,
 				3A4C945A1B5B21410088C3F2 /* FLEXResources.m */,
+				C37A0C91218BAC9600848CA7 /* FLEXObjcInternal.h */,
+				C37A0C92218BAC9600848CA7 /* FLEXObjcInternal.mm */,
 				3A4C945B1B5B21410088C3F2 /* FLEXRuntimeUtility.h */,
 				3A4C945C1B5B21410088C3F2 /* FLEXRuntimeUtility.m */,
 				3A4C945D1B5B21410088C3F2 /* FLEXUtility.h */,
@@ -717,6 +723,7 @@
 				3A4C94FD1B5B21410088C3F2 /* FLEXArgumentInputStructView.h in Headers */,
 				94A515141C4CA1C00063292F /* FLEXManager.h in Headers */,
 				3A4C95201B5B21410088C3F2 /* FLEXFileBrowserFileOperationController.h in Headers */,
+				C37A0C93218BAC9600848CA7 /* FLEXObjcInternal.h in Headers */,
 				3A4C953E1B5B21410088C3F2 /* FLEXNetworkTransactionDetailTableViewController.h in Headers */,
 				3A4C95301B5B21410088C3F2 /* FLEXSystemLogMessage.h in Headers */,
 				3A4C95361B5B21410088C3F2 /* FLEXNetworkHistoryTableViewController.h in Headers */,
@@ -947,6 +954,7 @@
 				3A4C95351B5B21410088C3F2 /* FLEXSystemLogTableViewController.m in Sources */,
 				3A4C95271B5B21410088C3F2 /* FLEXGlobalsTableViewController.m in Sources */,
 				779B1ED31C0C4D7C001F5E49 /* FLEXTableColumnHeader.m in Sources */,
+				C37A0C94218BAC9600848CA7 /* FLEXObjcInternal.mm in Sources */,
 				3A4C94EA1B5B21410088C3F2 /* FLEXHierarchyTableViewController.m in Sources */,
 				3A4C95331B5B21410088C3F2 /* FLEXSystemLogTableViewCell.m in Sources */,
 				C3DB9F652107FC9600B46809 /* FLEXObjectRef.m in Sources */,