zig

build.zig (8477B) - Raw

---

 const std = @import("std");
 
 // Although this function looks imperative, it does not perform the build
 // directly and instead it mutates the build graph (`b`) that will be then
 // executed by an external runner. The functions in `std.Build` implement a DSL
 // for defining build steps and express dependencies between them, allowing the
 // build runner to parallelize the build automatically (and the cache system to
 // know when a step doesn't need to be re-run).
 pub fn build(b: *std.Build) void {
     // Standard target options allow the person running `zig build` to choose
     // what target to build for. Here we do not override the defaults, which
     // means any target is allowed, and the default is native. Other options
     // for restricting supported target set are available.
     const target = b.standardTargetOptions(.{});
     // Standard optimization options allow the person running `zig build` to select
     // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
     // set a preferred release mode, allowing the user to decide how to optimize.
     const optimize = b.standardOptimizeOption(.{});
     // It's also possible to define more custom flags to toggle optional features
     // of this build script using `b.option()`. All defined flags (including
     // target and optimize options) will be listed when running `zig build --help`
     // in this directory.
 
     // This creates a module, which represents a collection of source files alongside
     // some compilation options, such as optimization mode and linked system libraries.
     // Zig modules are the preferred way of making Zig code available to consumers.
     // addModule defines a module that we intend to make available for importing
     // to our consumers. We must give it a name because a Zig package can expose
     // multiple modules and consumers will need to be able to specify which
     // module they want to access.
     const mod = b.addModule("_NAME", .{
         // The root source file is the "entry point" of this module. Users of
         // this module will only be able to access public declarations contained
         // in this file, which means that if you have declarations that you
         // intend to expose to consumers that were defined in other files part
         // of this module, you will have to make sure to re-export them from
         // the root file.
         .root_source_file = b.path("src/root.zig"),
         // Later on we'll use this module as the root module of a test executable
         // which requires us to specify a target.
         .target = target,
     });
 
     // Here we define an executable. An executable needs to have a root module
     // which needs to expose a `main` function. While we could add a main function
     // to the module defined above, it's sometimes preferable to split business
     // logic and the CLI into two separate modules.
     //
     // If your goal is to create a Zig library for others to use, consider if
     // it might benefit from also exposing a CLI tool. A parser library for a
     // data serialization format could also bundle a CLI syntax checker, for example.
     //
     // If instead your goal is to create an executable, consider if users might
     // be interested in also being able to embed the core functionality of your
     // program in their own executable in order to avoid the overhead involved in
     // subprocessing your CLI tool.
     //
     // If neither case applies to you, feel free to delete the declaration you
     // don't need and to put everything under a single module.
     const exe = b.addExecutable(.{
         .name = "_NAME",
         .root_module = b.createModule(.{
             // b.createModule defines a new module just like b.addModule but,
             // unlike b.addModule, it does not expose the module to consumers of
             // this package, which is why in this case we don't have to give it a name.
             .root_source_file = b.path("src/main.zig"),
             // Target and optimization levels must be explicitly wired in when
             // defining an executable or library (in the root module), and you
             // can also hardcode a specific target for an executable or library
             // definition if desireable (e.g. firmware for embedded devices).
             .target = target,
             .optimize = optimize,
             // List of modules available for import in source files part of the
             // root module.
             .imports = &.{
                 // Here "_NAME" is the name you will use in your source code to
                 // import this module (e.g. `@import("_NAME")`). The name is
                 // repeated because you are allowed to rename your imports, which
                 // can be extremely useful in case of collisions (which can happen
                 // importing modules from different packages).
                 .{ .name = "_NAME", .module = mod },
             },
         }),
     });
 
     // This declares intent for the executable to be installed into the
     // install prefix when running `zig build` (i.e. when executing the default
     // step). By default the install prefix is `zig-out/` but can be overridden
     // by passing `--prefix` or `-p`.
     b.installArtifact(exe);
 
     // This creates a top level step. Top level steps have a name and can be
     // invoked by name when running `zig build` (e.g. `zig build run`).
     // This will evaluate the `run` step rather than the default step.
     // For a top level step to actually do something, it must depend on other
     // steps (e.g. a Run step, as we will see in a moment).
     const run_step = b.step("run", "Run the app");
 
     // This creates a RunArtifact step in the build graph. A RunArtifact step
     // invokes an executable compiled by Zig. Steps will only be executed by the
     // runner if invoked directly by the user (in the case of top level steps)
     // or if another step depends on it, so it's up to you to define when and
     // how this Run step will be executed. In our case we want to run it when
     // the user runs `zig build run`, so we create a dependency link.
     const run_cmd = b.addRunArtifact(exe);
     run_step.dependOn(&run_cmd.step);
 
     // By making the run step depend on the default step, it will be run from the
     // installation directory rather than directly from within the cache directory.
     run_cmd.step.dependOn(b.getInstallStep());
 
     // This allows the user to pass arguments to the application in the build
     // command itself, like this: `zig build run -- arg1 arg2 etc`
     if (b.args) |args| {
         run_cmd.addArgs(args);
     }
 
     // Creates an executable that will run `test` blocks from the provided module.
     // Here `mod` needs to define a target, which is why earlier we made sure to
     // set the releative field.
     const mod_tests = b.addTest(.{
         .root_module = mod,
     });
 
     // A run step that will run the test executable.
     const run_mod_tests = b.addRunArtifact(mod_tests);
 
     // Creates an executable that will run `test` blocks from the executable's
     // root module. Note that test executables only test one module at a time,
     // hence why we have to create two separate ones.
     const exe_tests = b.addTest(.{
         .root_module = exe.root_module,
     });
 
     // A run step that will run the second test executable.
     const run_exe_tests = b.addRunArtifact(exe_tests);
 
     // A top level step for running all tests. dependOn can be called multiple
     // times and since the two run steps do not depend on one another, this will
     // make the two of them run in parallel.
     const test_step = b.step("test", "Run tests");
     test_step.dependOn(&run_mod_tests.step);
     test_step.dependOn(&run_exe_tests.step);
 
     // Just like flags, top level steps are also listed in the `--help` menu.
     //
     // The Zig build system is entirely implemented in userland, which means
     // that it cannot hook into private compiler APIs. All compilation work
     // orchestrated by the build system will result in other Zig compiler
     // subcommands being invoked with the right flags defined. You can observe
     // these invocations when one fails (or you pass a flag to increase
     // verbosity) to validate assumptions and diagnose problems.
     //
     // Lastly, the Zig build system is relatively simple and self-contained,
     // and reading its source code will allow you to master it.
 }