Update README

Author: jurvis

README.md

@@ -6,7 +6,7 @@ Automatic Swift bindings generation for [`rust-lightning`](https://github.com/li
 
 In order to use the automatically generated bindings, simply drag `*.xcframework` file into an Xcode project.
 
-The `*.xcframework` files are either available on 
+The `*.xcframework` files are either available on
 the [Releases](https://github.com/lightningdevkit/ldk-swift/releases) page, or can be [compiled](#Compilation)
 from scratch.
 
@@ -15,54 +15,60 @@ from scratch.
 
 ### Prerequisites
 
-- A Mac with Xcode
+- A Mac with Xcode 13.2.1 or lower (this is because there is a bug with `cc` that prevents it from compiling for Mac Catalyst targets with clang 13)
 - Python3
 - Rust
+- `gnu-sed` (optional; but will cut your compile times significantly!)
 
 For Rust specifically, there are a couple additional requirements that can be installed once the Rust toolchain
 is set up:
 
 ```shell
+rustup toolchain install nightly
 rustup target add aarch64-apple-darwin aarch64-apple-ios x86_64-apple-ios
-cargo install cargo-lipo
 cargo install cbindgen
 ```
 
 ### Cloning Dependencies
 
+Before you get started, make sure you `cd` to the `ldk-swift` directory.
+
 In order to generate these bindings from scratch, you will need to clone two dependency repositories:
 
-**rust-lightning**, (a specific branch built for bindings compatibility) 
+**rust-lightning**, (a specific branch built for bindings compatibility)
 ```shell
-git clone --branch 2021-03-java-bindings-base git@github.com:TheBlueMatt/rust-lightning.git
+git clone --branch 2021-03-java-bindings-base https://github.com/TheBlueMatt/rust-lightning bindings/artifacts/rust-lightning
 ```
 
 **ldk-c-bindings**
 ```shell
-git clone git@github.com:lightningdevkit/ldk-c-bindings.git
+git clone https://github.com/lightningdevkit/ldk-c-bindings bindings/artifacts/ldk-c-bindings
 ```
 
+For compilation to work properly, make sure that both `rust-lightning` and `ldk-c-bindings` are present in `ldk-swift/bindings/artifacts`.
+
 ### Generating Rust-to-C-bindings
 
 Now, navigate to the `ldk-c-bindings` directory and run the `genbindings.sh` script:
 
 ```shell
-cd /path/to/ldk-c-bindings
+pushd bindings/artifacts/ldk-c-bindings
 ./genbindings.sh /path/to/rust-lightning true
+popd
 ```
 
 ### Generating C-to-Swift-bindings
 
 <details>
 <summary>If using Docker</summary>
 
-If you're using Docker to generate the Swift bindings, navigate (if you're not already there from the 
+If you're using Docker to generate the Swift bindings, navigate (if you're not already there from the
 previous step) to the `ldk-c-bindings` directory and open the file located here:
 
 `/path/to/ldk-c-bindings/lightning-c-bindings/Cargo.toml`
 
-In that file, you will see four lines specifying the `lightning`, `lightning-persister`, `lightning-invoice`, and 
-`lightning-background-processor` dependencies. They will most likely show local paths to the `rust-lightning` 
+In that file, you will see four lines specifying the `lightning`, `lightning-persister`, `lightning-invoice`, and
+`lightning-background-processor` dependencies. They will most likely show local paths to the `rust-lightning`
 folder due to the previous `genbindings.sh` step. As Docker won't have access to local paths,
 replace those lines with the following:
 
@@ -73,48 +79,35 @@ lightning-invoice = { git = "https://github.com/thebluematt/rust-lightning", bra
 lightning-background-processor = { git = "https://github.com/thebluematt/rust-lightning", branch = "2021-03-java-bindings-base", default-features = false }
 ```
 
-You will note that the revision is unspecified and is currently just placeholder `xxx`s. To obtain the revision, 
+You will note that the revision is unspecified and is currently just placeholder `xxx`s. To obtain the revision,
 just navigate to the just clone custom `rust-lightning` directory and run:
 
 ```shell
 cd /path/to/rust-lightning
 git rev-parse HEAD
 ```
 
-Take that commit hash and replace the `xxx` instances with it. 
+Take that commit hash and replace the `xxx` instances with it.
 </details>
 
 #### Generating the Swift files
 
 To generate the Swift files, navigate to the `ldk-swift` repository and run the following:
 
 ```shell
-EXPORT LDK_SWIFT_GENERATOR_INPUT_HEADER_PATH="/path/to/ldk-c-bindings/lightning-c-bindings/include/lightning.h"
+export LDK_SWIFT_GENERATOR_INPUT_HEADER_PATH="$(pwd)/bindings/artifacts/ldk-c-bindings/lightning-c-bindings/include/lightning.h"
 python3 ./
 ```
 
 Now, the contents of the `bindings/LDK` folder will have been completely regenerated.
 
 #### Generating the *.xcframework files
 
-With the Swift files completely regenerated, you will need to make sure the Xcode projects that serve as bases
-for the `*.xcframework`s reference them correctly. So navigate here:
-
-`path/to/ldk-swift/xcode`
-
-and open the respective `*.xcodeproj` files located in the `LDKFramework` and `LDKFramework_Mac` directories. 
-Do the following steps for _both_ projects:
-
-1. Remove the `LDK` references in the Xcode file tree
-2. Drag the `path/to/ldk-swift/bindings/LDK` folder to that same location in the file tree
-3. Check `Copy items if needed` and pick `Create groups` in the dialog box
-
-Next, navigate back to the `xcode` directory, and run the following scripts:
+With all the bindings generated, you will just have to run two commands to generate the xcframework:
 
 ```shell
-./compile_dependency_binaries.sh /path/to/ldk-c-bindings
-./build_framework.sh 
+cd xcode
+./build_framework.sh
 ```
 
-Finally, navigate to `path/to/ldk-swift/bindings/bin`, and you should find multiple `*.xcframework` files
-waiting for you there.
+Once the script finishes running, you should see `LDKFramework.xcframework` in the `xcode/build` folder. Drag that into your project, and you're done!