Releases · gnustep/libobjc2

22 Mar 08:47

v2.2.1

dd9128a

GNUstep Objective-C Runtime 2.2.1 Latest

Latest

This a bugfix release for the second update to the second major release of
the GNUstep Objective-C runtime (a.k.a. libobjc2). This runtime was designed
to support the features of modern dialects of Objective-C for use with GNUstep and
other Objective-C programs.

Highlights of this release include:

Various improvements for building and using libobjc2 on MinGW.
Improved support for the PowerPC architecture.
A fix for the detection of the tls-robin-map dependency.

You may obtain the code for this release from git and use the 2.2.1 branch:

https://github.com/gnustep/libobjc2.git

Alternatively, a tarball is available from:

https://github.com/gnustep/libobjc2/archive/v2.2.1.zip
https://github.com/gnustep/libobjc2/archive/v2.2.1.tar.gz

The runtime library is responsible for implementing the core features of the
object model, as well as exposing introspection features to the user. The
GNUstep runtime implements a superset of Apple's Objective-C Runtime APIs.

If you come across any problems, please file them in the issue tracker:

https://github.com/gnustep/libobjc2/issues

Assets 2

04 Feb 08:52

davidchisnall

v2.2

7c2ecce

GNUstep Objective-C Runtime 2.2

This is the second update to the second major release of the GNUstep Objective-C
runtime (a.k.a. libobjc2). This runtime was designed to support the features
of modern dialects of Objective-C for use with GNUstep and other Objective-C
programs.

Highlights of this release include:

Initial support for RISC-V 64-bit (rv64) including an architecture-specific
objc_msgSend, and block trampoline implementation. Please note that
double-precision floating-point support (rv64d) is required for the
objc_msgSend implementation.
Initial support for Windows on ARM64 with fast-path objc_msgSend.
Numerous improvements to the Objective-C++ exception interoperation code.
The runtime now dynamically detects whether the libcxxrt, libsupc++, or
libc++abi variant of the Itanium C++ Exception ABI is being used. This is
the first version to support exception interoperability with libc++abi.
Because we no longer need to identify the specific C++ runtime, we can link
to it indirectly via the C++ standard library, which enables more C++ to be
used in the Objective-C runtime.
The minimum CMake version has been bumped to 3.16, which supports
Objective-C. This support is now used, simplifying the build.
Support for GC mode is gone. Apple dropped support for this a long time ago.
objc_setUncaughtExceptionHandler is added, which avoids consuming code
needing to access a library-owned global.
The selector-table code has been rewritten in C++, improving performance of
adding selectors. This is unlikely to have a measurable impact on
performance outside of contrived test cases, but the new code is more
maintainable.
Several bug fixes in the ARC code, especially in corner cases surrounding
weak references.
Support for fast-path allocation / initialisation functions. Root classes
that opt into this should implement +_TrivialAllocInit (this can be an
empty method, it is not called). Clang 18 or later will emit calls to the
fast-path functions for +alloc, +allocWithZone: and +alloc + -init
calls. This should improve code density as well as performance.

You may obtain the code for this release from git and use the 2.2 branch:

https://github.com/gnustep/libobjc2.git

Alternatively, a tarball is available from:

https://github.com/gnustep/libobjc2/archive/v2.2.zip
https://github.com/gnustep/libobjc2/archive/v2.2.tar.gz

If you come across any problems, please file them in the issue tracker:

https://github.com/gnustep/libobjc2/issues

Assets 2

23 Aug 15:15

davidchisnall

v2.1

282486d

GNUstep Objective-C Runtime 2.1

This is the first update to the second major release of the GNUstep Objective-C
runtime (a.k.a. libobjc2). This runtime was designed to support the features
of modern dialects of Objective-C for use with GNUstep and other Objective-C
programs.

NOTE: This is the first release to use submodules. If you are downloading
the sources from git, please make sure that you do a recursive clone. If you
forget, the build system will give you instructions to correct this.
Tarballs from GitHub do not include submodules, so if you are downloading the
tarball then you will need to download the submodule separately.

Highlights of this release include:

Numerous improvements to the Objective-C++ exception interoperation code.
The runtime now dynamically detects whether the libcxxrt or libsupc++ variant
of the Itanium C++ Exception ABI is being used
Sending a message to super where the corresponding method did not exist was
silently ignored in previous versions of the runtime. This now correctly
invokes the forwarding hooks and so (with an implementation of the Foundation
framework, such as GNUstep Base or WinObjC) will trigger an exception or
invoke forwardInvocation:.
The checks for overloaded memory management methods were incorrect, causing
some classes to be incorrectly opted into ARC fast paths. These checks are
now correct.
Several memory management bugs in corner cases of weak reference management
were fixed.
The ARM assembly implementation of objc_msgSend now correctly restores the
stack after calling a forwarding implementation. This bug caused stack
corruption and usually crashing on ARM.
The ARC code has been rewritten as C++, using a well-tested third-party
Robin-Hood hash table to store weak references, replacing the home-grown
version. This improves performance and reduces the likelihood of bugs
arising from the hash table implementation.
Control Flow Guard (CGF) checks were added on Windows on x86 (32- and
64-bit). If Objective-C code is compiled with CFG enabled then
objc_msgSend will crash if it attempts to jump to an address that is not a
valid function entry point.
The function signatures in the blocks headers were updated for compatibility
with recent macOS releases.
Support for the C11 _Atomic type qualifier in property metadata was added.

You may obtain the code for this release from git and use the 2.1 branch:

https://github.com/gnustep/libobjc2.git

Alternatively, a tarball is available from:

https://github.com/gnustep/libobjc2/archive/v2.1.zip
https://github.com/gnustep/libobjc2/archive/v2.1.tar.gz

The submodule is available from:

https://github.com/Tessil/robin-map/archive/757de82.zip
https://github.com/Tessil/robin-map/archive/757de82.tar.gz

This will extract as robin-map-757de829927489bee55ab02147484850c687b620.
You must move the contents of that directory into third_party/robin_map in the
libobjc2 tree.

If you come across any problems, please file them in the issue tracker:

https://github.com/gnustep/libobjc2/issues

Assets 4

26 Apr 08:32

davidchisnall

v2.0

9d790b4

GNUstep Objective-C Runtime 2.0

This the second major release of the GNUstep Objective-C runtime (a.k.a.
libobjc2). This runtime was designed to support the features of modern
dialects of Objective-C for use with GNUstep and other Objective-C programs.

This release introduces a new Objective-C ABI, which is designed to be forward
compatible with future changes and removes a large number of hacks that were
required for compatibility with the prior ABI that included features introduced
in the 1980s. Highlights include:

The linker now removes duplicate selectors within a library.
The linker will remove duplicate protocol definitions within a library.
Protocols and classes are now always accessed via an indirection layer, so
they can be extended by future versions of the ABI without breaking
compatibility.
Categories can include property metadata and both categories.
Constant strings are now emitted with a richer structure, which provides
faster hashing and better unicode support.
Instance variable metadata includes size and alignment, allowing better object
layout and more accurate introspection. Instance variable metadata now
includes more accurate information about ARC ownership semantics.
Method metadata now includes extended type information, allowing bridged
languages to understand the class that methods expect and not just the fact
that they take an object. This was previously an obstacle to supporting
JavaScriptCore's Objective-C bridge with GNUstep.

In addition to the new ABI, there are several improvements on Windows:

The runtime now uses SEH-based exception handling on Windows. This
interoperates with C++ exceptions in libraries compiled with MSVC or
MSVC-compatible compilers.
All of the assembly code paths now fully support i386 and x64 Windows.
Object allocations on 32-bit Windows now use _aligned_malloc to guarantee
sufficient alignment for AVX vectors in instance variables.
The runtime now uses fibre-local storage and critical sections on Windows,
improving performance in multithreaded workloads on Windows.
Public runtime functions are now marked dllexport, so the runtime can be built
as objc.dll on Windows.

WARNING: The new ABI is currently incompatible with incremental linking on
Windows, so projects built with Microsoft's linker must disable incremental
linking.

Note: Microsoft's WinObjC project contains a friendly fork of this library that
includes a work around for the incremental linking issue. If you wish to use
incremental linking on Windows, please use that version. A subsequent version
of clang and link.exe should include a fix that will make it possible to use
this version with incremental linking.

The runtime will now use the new ABI's data structures internally and will
automatically upgrade on-disk structures from old ABIs when used with the old
ABI. As a result, memory usage will be higher when using the old ABI and users
who are unable to recompile their code may prefer to stick with the 1.9.x
release series. Mixing libraries compiled with the old and new ABIs is not
supported and will abort at run time.

The new ABI provides better run-time introspection metadata and smaller
binaries. When used with the new ABI, this version of the runtime will consume
less memory than the previous release.

You may obtain the code for this release from git and use the 2.0 branch:

https://github.com/gnustep/libobjc2.git

Alternatively, a tarball is available from:

https://github.com/gnustep/libobjc2/archive/v2.0.zip
https://github.com/gnustep/libobjc2/archive/v2.0.tar.gz

If you come across any problems, please file them in the issue tracker:

https://github.com/gnustep/libobjc2/issues

Assets 4

26 Apr 08:18

davidchisnall

v1.9

32a7f60

GNUstep Objective-C Runtime 1.9

This the ninth official release of the GNUstep Objective-C runtime (a.k.a.
libobjc2). This runtime was designed to support the features of modern
dialects of Objective-C for use with GNUstep and other Objective-C programs.
Highlights of this release include:

Support for 64-bit ARM (AArch64) processors, including assembly fast paths
for message sending.
Improved the dispatch table representation to improve performance and cache
usage on the fast path.
The implementation of imp_implementationWithBlock, the function that allows
blocks to be used as methods, no longer requires physical pages to be mapped
both writeable and executable.
Numerous improvements to the interaction between runtime functions and ARC.
Support for Thumb-2 interworking on ARM. Note that the library must be
compiled for ARMv7 or ARMv6T2 for this code to be enabled. Once it has been,
other Objective-C binaries linked with the library can be compiled as ARM or
Thumb-2 code. This will also generate Thumb-2 message send functions,
improving instruction cache usage.
Significant improvements to ARC, including
- The runtime no longer acquires a global lock on every object deallocation (a
  global lock is still used for objects that have weak references). NOTE:
  This is incompatible with other code directly inspecting the reference
  count and will break with older versions of GNUstep Base!
- Weak references use a scheme closer to C++ std::weak_pointer and are
  lazily zeroed on access. This reduces the space overheads for weak
  references.
- Some additional helper functions are added for use in NSObject and other
  root classes, which simplifies the layering between the runtime and the
  Foundation (or equivalent) implementation.
Improvements to how the runtime handles layout of ivars with strong alignment
requirements, which should fix issues relating to using vector types in
Objective-C objects.
The option to build a separate libobjcxx has been removed. The runtime will
now depend on the C++ standard library implementation if no useable C++
runtime is available. Note that C++ exception interworking does not work
because LLVM's libc++abi (shipped by Apple) does not provide GNU-compatible
hooks and so Objective-C++ exception support will be automatically disabled
on this platform. Any other platforms shipping libc++abi should consider
either GNU libsupc++ or libcxxrt as an alternative.

You may obtain the code for this release from git and use the 1.9 branch:

https://github.com/gnustep/libobjc2.git

Alternatively, a tarball is available from:

https://github.com/gnustep/libobjc2/archive/v1.9.zip
https://github.com/gnustep/libobjc2/archive/v1.9.tar.gz

If you come across any problems, please file them in the issue tracker:

https://github.com/gnustep/libobjc2/issues

Assets 2

07 Aug 11:34

davidchisnall

v1.8.1

5a21dd1

GNUstep Objective-C Runtime 1.8.1

This a bugfix release for the ninth official release of the GNUstep Objective-C
runtime (a.k.a. libobjc2). This runtime was designed to support the features
of modern dialects of Objective-C for use with GNUstep and other Objective-C
programs. Highlights of this release include:

Better build system detection of LLVM not being present
Fix for a bug causing corruption of runtime state when hidden classes are
deallocated.

You may obtain the code for this release from git and use the 1.8 branch:

https://github.com/gnustep/libobjc2.git

Alternatively, a tarball is available from:

https://github.com/gnustep/libobjc2/archive/v1.8.zip
https://github.com/gnustep/libobjc2/archive/v1.8.tar.gz

This library is based on the Étoilé Objective-C Runtime, an earlier research
prototype, and includes support for non-fragile instance variables,
type-dependent dispatch, and object planes. It is fully backwards compatible
with the FSF's GCC 4.2.1 Objective-C ABI and also implements a new ABI that is
supported by Clang and Étoilé's LanguageKit and is required for some of the
newer features.

If you come across any problems, please file them in the issue tracker:

https://github.com/gnustep/libobjc2/issues

Assets 2