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diff --git a/md/writeup/hello_world_swift.md b/md/writeup/hello_world_swift.md deleted file mode 100644 index 5e39407..0000000 --- a/md/writeup/hello_world_swift.md +++ /dev/null @@ -1,386 +0,0 @@ -title:Linux Hello world in Swift -keywords:linux,swift - -# Linux Hello world in Swift -## Intro - -Swift is one of cool modern languages, that appeared recently on the scene. -Purpose of Swift is replace C/ObjectC/C++ on MacOS. In same time its works on Linux. -Support of Swift for Linux is not that great there is lack of many libraries and all -Siwft power opens on Macos, but its still some fun language to play. Main swift page -provides only Macos and Ubuntu as main supported platforms. Anything else you may have -troubles to get working. Currently supported architectures are intel64 and arm64. -Lets get into this journey of running Swift on Linux. - -## Installing Swift -### Ubuntu - -Installing on Ubuntu is most easiest part, download from main page and done. -[https://swift.org/download/](https://swift.org/download/) - -```bash -wget -c https://swift.org/builds/swift-5.1.4-release/ubuntu1804/swift-5.1.4-RELEASE/swift-5.1.4-RELEASE-ubuntu18.04.tar.gz -tar -xvf swift-5.1.4-RELEASE-ubuntu18.04.tar.gz -``` - -### Archlinux - -Installing from main swift page, not able to compile because of missing GCC flags. -So easiest way to install is from AUR -[https://aur.archlinux.org/packages/swift-bin/](https://aur.archlinux.org/packages/swift-bin/) -Compiling other swift package from AUR have same issues, related to not able to compile source. - -```bash -wget -c https://aur.archlinux.org/cgit/aur.git/snapshot/swift-bin.tar.gz -tar -xvf swift-bin.tar.gz -cd siwft-bin -makepkg -sudo pacman -U -``` - -## Compile Swift - -All this examples given for Swift version 5.1 - -```bash -mkdir HelloWorld -cd ./HelloWorld/ -swift package init --type executable -swift run -``` - -Compiled file is located in -```bash -./.build/debug/HelloWorld -``` - - -## Static Swift Compilation - -Swift static compilation compiles in all Swift runtime and uses default Linux libraries. - -```bash -swift build -c release -Xswiftc -static-stdlib -``` - -File is located in ./.build/x86_64-unknown-linux/release/HelloWorld -```bash -ls -lah ./.build/x86_64-unknown-linux/release/HelloWorld --rwxr-xr-x 1 fam fam 34M Mar 1 18:29 ./.build/x86_64-unknown-linux/release/HelloWorld - -ldd ./.build/x86_64-unknown-linux/release/HelloWorld - linux-vdso.so.1 (0x00007ffebcd17000) - libdl.so.2 => /usr/lib/libdl.so.2 (0x00007efc5a6d4000) - libpthread.so.0 => /usr/lib/libpthread.so.0 (0x00007efc5a6b2000) - libatomic.so.1 => /usr/lib/libatomic.so.1 (0x00007efc5a6a8000) - libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00007efc5a4bf000) - libm.so.6 => /usr/lib/libm.so.6 (0x00007efc5a379000) - libgcc_s.so.1 => /usr/lib/libgcc_s.so.1 (0x00007efc5a35f000) - libc.so.6 => /usr/lib/libc.so.6 (0x00007efc5a197000) - /lib64/ld-linux-x86-64.so.2 => /usr/lib64/ld-linux-x86-64.so.2 (0x00007efc5c624000) -``` - -## Swift on ARM64 - -Swift installation manual for RasPi4 - -[https://swift-arm.com/install-swift/](https://swift-arm.com/install-swift/) - -```bash -curl -s https://packagecloud.io/install/repositories/swift-arm/release/script.deb.sh | sudo bash -sudo apt-get install swift5 -``` - -Now steps from beginning could be followed. And result will be same. - - -## Interfacing to C - -Swift is based on clang/llvm and able to parse C language and create interface to Swift. -Its eliminates need to write glue/binding library for Swift and simplifies C integration. - - -```bash -mkdir Cint0 -cd Cint0 -swift package init --type executable -``` - - -Define C header with functions to be binded -_code.h_ -```c -#ifndef __CCODE_H -#define __CCODE_H - -#include <stdlib.h> -#include <stdio.h> - -int one(); -int two(); -int calc(int a, int b); - -#endif -``` - -Function implementation - -_code.c_ -```c -#include "include/code.h" - -int one() -{ - printf("First\n"); - return 1; -} - -int two() -{ - printf("Second\n"); - return 2; -} - -int calc(int a, int b) -{ - return a+b; -} -``` - -_main.swift_ -```swift -import ccode; - -print("Start program") - -print(one()); -print(ccode.two()); -print(calc(12,12)) - -print("End program") -``` - -C source and header files are ready. Swift code that using C code is written. -So its time to define package and build everything. Package.swift defines -what is included in source and dependencies. So add target "Cint0" with -dependencies on "ccode" that is our C code. -And then add extra target that will compile code "ccode" and doesn't depend on -anything. ... and build. - -_Package.swift_ -```swift -// swift-tools-version:5.1 -// The swift-tools-version declares the minimum version of Swift required to build this package. - -import PackageDescription - -let package = Package( - name: "Cint0", - dependencies: [ - // Dependencies declare other packages that this package depends on. - // .package(url: /* package url */, from: "1.0.0"), - ], - - targets: [ - // Targets are the basic building blocks of a package. A target can define a module or a test suite. - // Targets can depend on other targets in this package, and on products in packages which this package depends on. - .target( - name:"Cint0", - dependencies: ["ccode"]), - .testTarget( - name: "Cint0Tests", - dependencies: ["Cint0"]), - .target( - name:"ccode", - dependencies: []), - - ] -) -``` - - - -## SDL2 example - -### Binding SDL2 library - -To use C SDL2 headers from Swift we need to create bindings. This also shows how to bind C code to Swift - -```bash -mkdir CSDL2 -cd CSDL2 -swift package init --type system-module -``` - - -Resulting files are -``` -$ swift package init --type system-module -Creating system-module package: CSDL2 -Creating Package.swift -Creating README.md -Creating .gitignore -Creating module.modulemap -``` - -Create __Headers__ directory and add there file -_CSDL2-Header.h_ -```c -#include <SDL2/SDL.h> -``` - -_Package.swift_ -```swift -// swift-tools-version:5.1 -// The swift-tools-version declares the minimum version of Swift required to build this package. - -import PackageDescription - -let package = Package( - name: "CSDL2", - products: [ - // Products define the executables and libraries produced by a package, and make them visible to other packages. - .library( - name: "CSDL2", - targets: ["CSDL2"]), - ], - dependencies: [ - // Dependencies declare other packages that this package depends on. - // .package(url: /* package url */, from: "1.0.0"), - ], - targets: [ - // Targets are the basic building blocks of a package. A target can define a module or a test suite. - // Targets can depend on other targets in this package, and on products in packages which this package depends on. - .target( - name: "CSDL2", - dependencies: []), - .testTarget( - name: "CSDL2Tests", - dependencies: ["CSDL2"]), - ] -) -``` - - -Here is main thing, to tell Swift with headers to make accessible -_module.modulemap_ -``` -module CSDL2 { - header "Headers/CSDL2-Header.h" - link "SDL2" - export * -} -``` - -Now its time to test CSDL2 package - -### SDL2 test with bindings - -SDL2 test -```bash -mkdir SDLtest -cd ./SDLtest -swift package init --type executable -``` - -Small SDL2 example in C -```c -#include <SDL2/SDL.h> - -#define SCREEN_WIDTH 200 -#define SCREEN_HEIGHT 200 - -char quit = 0; -SDL_Window *window = NULL; -SDL_Renderer *renderer = NULL; - -int main() -{ - SDL_Init(SDL_INIT_VIDEO); - window = SDL_CreateWindow( - "WEBASM", - SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, - SCREEN_WIDTH, SCREEN_HEIGHT, - SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL); - renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED); - SDL_SetRenderDrawColor(renderer, 0xff, 0xff, 0xff, 0xff); - int quit=0; - while(0 == quit) - { - SDL_Event event; - while (SDL_PollEvent(&event)) - { - switch (event.type) - { - case SDL_QUIT: - { - quit = 1; - break; - } - } - } - } - SDL_DestroyRenderer(renderer); - SDL_DestroyWindow(window); - SDL_Quit(); -} -``` - -Lets convert C example to working with Swift code - -Pointers can be defined as OpaquePointer without type so far. -All functions are called same as in C. -Enum types if they are passed then can be accessed as NAME.rawValue . - - -```swift -import CSDL2 - -var windowPtr: OpaquePointer! = nil -var renderPtr: OpaquePointer! = nil - -SDL_Init(0) -SDL_CreateWindowAndRenderer(200,200,0,&windowPtr,&renderPtr) -SDL_SetRenderDrawColor(renderPtr,0xff,0xff,0xff,0xff) -var quit = 0; -var e = SDL_Event(); -while quit == 0 { - while SDL_PollEvent(&e) != 0 - { - switch e.type { - case case SDL_QUIT.rawValue:: - quit = 1 - default: - print("Unknown event") - } - } -} - -print("Hello, world!") - -SDL_DestroyRenderer(renderPtr) -SDL_DestroyWindow(windowPtr) -SDL_Quit() -``` - -So far all Swift features looks like they are working out of the box, without -deep Swift knowledge was able to bind library, and used. Also this is largest code base -Swift code that I ever wrote in my life. So far it looks like easy language to learn. - -## Sources - - -## Links - -[01] [https://www.programiz.com/swift-programming](https://www.programiz.com/swift-programming) -[02] [https://swift.org/download/](https://swift.org/download/) -[03] [https://aur.archlinux.org/packages/swift-bin/](https://aur.archlinux.org/packages/swift-bin/) -[04] [https://swift-arm.com/install-swift/](https://swift-arm.com/install-swift/) -[05] [https://github.com/apple/swift-package-manager/blob/master/Documentation/Usage.md](https://github.com/apple/swift-package-manager/blob/master/Documentation/Usage.md) -[06] [https://theswiftdev.com/how-to-call-c-code-from-swift/](https://theswiftdev.com/how-to-call-c-code-from-swift/) -[07] [https://github.com/KevinVitale/SwiftSDL/blob/master/Package.swift](https://github.com/KevinVitale/SwiftSDL/blob/master/Package.swift) -[08] [https://rderik.com/blog/making-a-c-library-available-in-swift-using-the-swift-package/](https://rderik.com/blog/making-a-c-library-available-in-swift-using-the-swift-package/) -[09] [https://github.com/KevinVitale/SwiftSDL/tree/master/Sources](https://github.com/KevinVitale/SwiftSDL/tree/master/Sources) -[10] [https://www.uraimo.com/2016/04/07/swift-and-c-everything-you-need-to-know/#working-with-pointers](https://www.uraimo.com/2016/04/07/swift-and-c-everything-you-need-to-know/#working-with-pointers) -[11] [https://www.objc.io/blog/2018/01/30/opaque-vs-unsafe-pointers/](https://www.objc.io/blog/2018/01/30/opaque-vs-unsafe-pointers/) - |