1  # MacOS Deployment
  2  
  3  The `macdeployqtplus` script should not be run manually. Instead, after building as usual:
  4  
  5  ```bash
  6  make deploy
  7  ```
  8  
  9  When complete, it will have produced `Bitcoin-Core.zip`.
 10  
 11  ## SDK Extraction
 12  
 13  ### Step 1: Obtaining `Xcode.app`
 14  
 15  A free Apple Developer Account is required to proceed.
 16  
 17  Our macOS SDK can be extracted from
 18  [Xcode_15.xip](https://download.developer.apple.com/Developer_Tools/Xcode_15/Xcode_15.xip).
 19  
 20  Alternatively, after logging in to your account go to 'Downloads', then 'More'
 21  and search for [`Xcode 15`](https://developer.apple.com/download/all/?q=Xcode%2015).
 22  
 23  An Apple ID and cookies enabled for the hostname are needed to download this.
 24  
 25  The `sha256sum` of the downloaded XIP archive should be `4daaed2ef2253c9661779fa40bfff50655dc7ec45801aba5a39653e7bcdde48e`.
 26  
 27  To extract the `.xip` on Linux:
 28  
 29  ```bash
 30  # Install/clone tools needed for extracting Xcode.app
 31  apt install cpio
 32  git clone https://github.com/bitcoin-core/apple-sdk-tools.git
 33  
 34  # Unpack the .xip and place the resulting Xcode.app in your current
 35  # working directory
 36  python3 apple-sdk-tools/extract_xcode.py -f Xcode_15.xip | cpio -d -i
 37  ```
 38  
 39  On macOS:
 40  
 41  ```bash
 42  xip -x Xcode_15.xip
 43  ```
 44  
 45  ### Step 2: Generating the SDK tarball from `Xcode.app`
 46  
 47  To generate the SDK, run the script [`gen-sdk`](./gen-sdk) with the
 48  path to `Xcode.app` (extracted in the previous stage) as the first argument.
 49  
 50  ```bash
 51  ./contrib/macdeploy/gen-sdk '/path/to/Xcode.app'
 52  ```
 53  
 54  The generated archive should be: `Xcode-15.0-15A240d-extracted-SDK-with-libcxx-headers.tar.gz`.
 55  The `sha256sum` should be `c0c2e7bb92c1fee0c4e9f3a485e4530786732d6c6dd9e9f418c282aa6892f55d`.
 56  
 57  ## Deterministic macOS App Notes
 58  
 59  macOS Applications are created in Linux by combining a recent `clang` and the Apple
 60  `binutils` (`ld`, `ar`, etc).
 61  
 62  Apple uses `clang` extensively for development and has upstreamed the necessary
 63  functionality so that a vanilla clang can take advantage. It supports the use of `-F`,
 64  `-target`, `-mmacosx-version-min`, and `-isysroot`, which are all necessary when
 65  building for macOS.
 66  
 67  Apple's version of `binutils` (called `cctools`) contains lots of functionality missing in the
 68  FSF's `binutils`. In addition to extra linker options for frameworks and sysroots, several
 69  other tools are needed as well such as `install_name_tool`, `lipo`, and `nmedit`. These
 70  do not build under Linux, so they have been patched to do so. The work here was used as
 71  a starting point: [mingwandroid/toolchain4](https://github.com/mingwandroid/toolchain4).
 72  
 73  In order to build a working toolchain, the following source packages are needed from
 74  Apple: `cctools`, `dyld`, and `ld64`.
 75  
 76  These tools inject timestamps by default, which produce non-deterministic binaries. The
 77  `ZERO_AR_DATE` environment variable is used to disable that.
 78  
 79  This version of `cctools` has been patched to use the current version of `clang`'s headers
 80  and its `libLTO.so` rather than those from `llvmgcc`, as it was originally done in `toolchain4`.
 81  
 82  To complicate things further, all builds must target an Apple SDK. These SDKs are free to
 83  download, but not redistributable. See the SDK Extraction notes above for how to obtain it.
 84  
 85  The Guix process builds 2 sets of files: Linux tools, then Apple binaries which are
 86  created using these tools. The build process has been designed to avoid including the
 87  SDK's files in Guix's outputs. All interim tarballs are fully deterministic and may be freely
 88  redistributed.
 89  
 90  As of OS X 10.9 Mavericks, using an Apple-blessed key to sign binaries is a requirement in
 91  order to satisfy the new Gatekeeper requirements. Because this private key cannot be
 92  shared, we'll have to be a bit creative in order for the build process to remain somewhat
 93  deterministic. Here's how it works:
 94  
 95  - Builders use Guix to create an unsigned release. This outputs an unsigned ZIP which
 96    users may choose to bless and run. It also outputs an unsigned app structure in the form
 97    of a tarball.
 98  - The Apple keyholder uses this unsigned app to create a detached signature, using the
 99    script that is also included there. Detached signatures are available from this [repository](https://github.com/bitcoin-core/bitcoin-detached-sigs).
100  - Builders feed the unsigned app + detached signature back into Guix. It uses the
101    pre-built tools to recombine the pieces into a deterministic ZIP.