build.zig
1 const std = @import("std"); 2 3 // Although this function looks imperative, it does not perform the build 4 // directly and instead it mutates the build graph (`b`) that will be then 5 // executed by an external runner. The functions in `std.Build` implement a DSL 6 // for defining build steps and express dependencies between them, allowing the 7 // build runner to parallelize the build automatically (and the cache system to 8 // know when a step doesn't need to be re-run). 9 pub fn build(b: *std.Build) void { 10 // Standard target options allow the person running `zig build` to choose 11 // what target to build for. Here we do not override the defaults, which 12 // means any target is allowed, and the default is native. Other options 13 // for restricting supported target set are available. 14 const target = b.standardTargetOptions(.{}); 15 16 // Standard optimization options allow the person running `zig build` to select 17 // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not 18 // set a preferred release mode, allowing the user to decide how to optimize. 19 const optimize = b.standardOptimizeOption(.{}); 20 21 // This creates a module, which represents a collection of source files alongside 22 // some compilation options, such as optimization mode and linked system libraries. 23 // Zig modules are the preferred way of making Zig code available to consumers. 24 // addModule defines a module that we intend to make available for importing 25 // to our consumers. We must give it a name because a Zig package can expose 26 // multiple modules and consumers will need to be able to specify which 27 // module they want to access. 28 const mod = b.addModule("zitadel", .{ 29 // The root source file is the "entry point" of this module. Users of 30 // this module will only be able to access public declarations contained 31 // in this file, which means that if you have declarations that you 32 // intend to expose to consumers that were defined in other files part 33 // of this module, you will have to make sure to re-export them from 34 // the root file. 35 .root_source_file = b.path("src/root.zig"), 36 37 // Having a target here is useful because we will also use this module for tests. 38 .target = target, 39 .optimize = optimize, 40 }); 41 42 mod.addIncludePath(b.path("include")); 43 mod.link_libc = true; 44 45 // Here we define an executable. An executable needs to have a root module 46 // which needs to expose a `main` function. While we could add a main function 47 // to the module defined above, it's sometimes preferable to split business 48 // logic and the CLI into two separate modules. 49 // 50 // If your goal is to create a Zig library for others to use, consider if 51 // it might benefit from also exposing a CLI tool. A parser library for a 52 // data serialization format could also bundle a CLI syntax checker, for example. 53 // 54 // If instead your goal is to create an executable, consider if users might 55 // be interested in also being able to embed the core functionality of your 56 // program in their own executable in order to avoid the overhead involved in 57 // subprocessing your CLI tool. 58 // 59 // If neither case applies to you, feel free to delete the declaration you 60 // don't need and to put everything under a single module. 61 const exe_root = b.createModule(.{ 62 // b.createModule defines a new module just like b.addModule but, 63 // unlike b.addModule, it does not expose the module to consumers of 64 // this package, which is why in this case we don't have to give it a name. 65 .root_source_file = b.path("src/main.zig"), 66 67 // Target and optimization levels must be explicitly wired in when 68 // defining an executable or library (in the root module), and you 69 // can also hardcode a specific target for an executable or library 70 // definition if desireable (e.g. firmware for embedded devices). 71 .target = target, 72 .optimize = optimize, 73 74 // List of modules available for import in source files part of the 75 // root module. 76 .imports = &.{ 77 // Here "zitadel" is the name you will use in your source code to 78 // import this module (e.g. `@import("zitadel")`). The name is 79 // repeated because you are allowed to rename your imports, which 80 // can be extremely useful in case of collisions (which can happen 81 // importing modules from different packages). 82 .{ .name = "zitadel", .module = mod }, 83 }, 84 }); 85 86 const exe = b.addExecutable(.{ 87 .name = "zitadel", 88 .root_module = exe_root, 89 }); 90 91 // Zig 0.16: include paths are configured on modules, not on the compile step. 92 // Use include/ if you have C-style headers there; use src/ only if you truly include from src/. 93 exe.root_module.addIncludePath(b.path("include")); 94 exe_root.addCSourceFiles(.{ 95 .files = &.{"modules/arithmetic/arithmetic.c"}, 96 .flags = &.{ "-Wall", "-Wextra" }, 97 }); 98 exe.root_module.link_libc = true; 99 100 // This declares intent for the executable to be installed into the 101 // install prefix when running `zig build` (i.e. when executing the default 102 // step). By default the install prefix is `zig-out/` but can be overridden 103 // by passing `--prefix` or `-p`. 104 b.installArtifact(exe); 105 106 // This creates a top level step. Top level steps have a name and can be 107 // invoked by name when running `zig build` (e.g. `zig build run`). 108 // This will evaluate the `run` step rather than the default step. 109 // For a top level step to actually do something, it must depend on other 110 // steps (e.g. a Run step, as we will see in a moment). 111 const run_step = b.step("run", "Run the app"); 112 113 // This creates a RunArtifact step in the build graph. A RunArtifact step 114 // invokes an executable compiled by Zig. Steps will only be executed by the 115 // runner if invoked directly by the user (in the case of top level steps) 116 // or if another step depends on it, so it's up to you to define when and 117 // how this Run step will be executed. In our case we want to run it when 118 // the user runs `zig build run`, so we create a dependency link. 119 const run_cmd = b.addRunArtifact(exe); 120 run_step.dependOn(&run_cmd.step); 121 122 // By making the run step depend on the default step, it will be run from the 123 // installation directory rather than directly from within the cache directory. 124 run_cmd.step.dependOn(b.getInstallStep()); 125 126 // This allows the user to pass arguments to the application in the build 127 // command itself, like this: `zig build run -- arg1 arg2 etc` 128 if (b.args) |args| { 129 run_cmd.addArgs(args); 130 } 131 132 // Creates an executable that will run `test` blocks from the provided module. 133 const mod_tests = b.addTest(.{ 134 .root_module = mod, 135 }); 136 137 // A run step that will run the test executable. 138 const run_mod_tests = b.addRunArtifact(mod_tests); 139 140 // Creates an executable that will run `test` blocks from the executable's 141 // root module. Note that test executables only test one module at a time, 142 // hence why we have to create two separate ones. 143 const exe_tests = b.addTest(.{ 144 .root_module = exe.root_module, 145 }); 146 147 // exe_tests.root_module.addIncludePath(b.path("include")); 148 // exe_tests.root_module.addCSourceFiles(.{ 149 // .files = &.{"modules/arithmetic/arithmetic.c"}, 150 // .flags = &.{}, 151 // }); 152 153 // A run step that will run the second test executable. 154 const run_exe_tests = b.addRunArtifact(exe_tests); 155 156 // A top level step for running all tests. dependOn can be called multiple 157 // times and since the two run steps do not depend on one another, this will 158 // make the two of them run in parallel. 159 const test_step = b.step("test", "Run tests"); 160 test_step.dependOn(&run_mod_tests.step); 161 test_step.dependOn(&run_exe_tests.step); 162 163 // Just like flags, top level steps are also listed in the `--help` menu. 164 // 165 // The Zig build system is entirely implemented in userland, which means 166 // that it cannot hook into private compiler APIs. All compilation work 167 // orchestrated by the build system will result in other Zig compiler 168 // subcommands being invoked with the right flags defined. You can observe 169 // these invocations when one fails (or you pass a flag to increase 170 // verbosity) to validate assumptions and diagnose problems. 171 // 172 // Lastly, the Zig build system is relatively simple and self-contained, 173 // and reading its source code will allow you to master it. 174 }