https://github.com/compnerd/uswift

μSwift[Core]
https://github.com/compnerd/uswift

swift

Last synced: 7 days ago
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μSwift[Core]

• Host: GitHub
• URL: https://github.com/compnerd/uswift
• Owner: compnerd
• License: bsd-3-clause
• Created: 2018-12-16T05:50:32.000Z (about 6 years ago)
• Default Branch: main
• Last Pushed: 2024-07-22T15:08:20.000Z (5 months ago)
• Last Synced: 2024-12-04T01:51:27.324Z (20 days ago)
• Topics: swift
• Language: Swift
• Homepage:
• Size: 78.1 KB
• Stars: 103
• Watchers: 13
• Forks: 9
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
μSwift[Core]

------------

The Swift language is implemented as a small layer of sugar over LLVM IR.  This

includes the core types such as `Bool`.  In order to support even basic

constructs, the language requires the standard library to be available.  The

reference standard library is a large code base and has additional dependencies

such as [libicu](https://icu-project.org).  This makes the library inconvenient

for certain environments.

μSwift is a minimal standard library that provides a few of the core interfaces

required for using basic constructs in Swift.  The long term vision for this

library is to provide conditional control over the features that the

implementation vends.  This enables the use of Swift in embedded systems which

may not be amenable to large libraries and do not need the complete core

functionality from Swift (e.g. Unicode support).

## Components

1. `swiftCore`: the standard library.

2. `swiftOnoneSupport`: the support library for building with `-Onone`

3. `swiftRuntime`: the language runtime support (merged into `swiftCore`)

## Build Requirements

- clang compiler (11.0+)

- Swift compiler (5.4+)

- CMake (3.18+)

- Ninja (1.8+)

## Building

Building a dynamically linked version of the libraries is controlled by the

`BUILD_SHARED_LIBS` standard parameter.

Building with CMake requires the Ninja build tool.

> **NOTE**: There is some support which is required in the Swift compiler itself in

> order to build the Swift stanard library.  This includes support for the

> architecture and the OS spelling.  Without this, the target may not be

> recognised properly and the Standard Library may fail to compile.

The following builds a release (optimized) configuration of the statically

linked variant of the standard library for a freestanding ELF environment:

```

cmake -B out -D BUILD_SHARED_LIBS=NO -D CMAKE_BUILD_TYPE=Release -D CMAKE_Swift_COMPILER_TARGET=aarch64-unknown-none-elf -D CMAKE_Swift_COMPILER_WORKS=YES -G Ninja -S .

ninja -C out

```

> **NOTE**: This support requires patches to the Swift compiler which have not yet

> been merged.  The changes are available at

> [apple/swift#35970](https://github.com/apple/swift/pull/35970).

### Parameters

1. `BUILD_SHARED_LIBS`: Boolean


Indicates if the libraries should be shared (dynamically linked) or not.

1. `CMAKE_Swift_COMPILER_TARGET`: String


Identifiers the target triple of the platform that the standard library should

be built.  Defaults to the build.

1. `CMAKE_Swift_COMPILER_WORKS`: Boolean


Required parameter.  Must always specify a true boolean value.  This is required

to skip the checks that the compiler can build code for the target.  The Swift

compiler cannot build code without the standard library available.  Because we

are building the standard library, we must skip the checks and assume that the

compiler functions properly.

## Artifacts



  
swiftCore.dll/libswiftCore.so/libswiftCore.dylib

  
The runtime component of the standard library.

  
swiftCore.lib/libswiftCore.so/libswiftCore.dylib

  
The build/SDK component of the standard library for linking.

  
Swift.swiftmodule

  
The build/SDK component of the standard library for building.