diff --git a/.gitignore b/.gitignore index e73c965..3389c86 100644 --- a/.gitignore +++ b/.gitignore @@ -1,2 +1,2 @@ -zig-cache/ +.zig-cache/ zig-out/ diff --git a/build.zig b/build.zig index 8000fc3..8898f49 100644 --- a/build.zig +++ b/build.zig @@ -1,35 +1,68 @@ const std = @import("std"); -// Although this function looks imperative, note that its job is to -// declaratively construct a build graph that will be executed by an external -// runner. +// 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 allows the person running `zig build` to choose + // 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. - _ = b.addModule("zba-util", .{ .root_source_file = .{ .path = "src/lib.zig" } }); - - // Creates a step for unit testing. This only builds the test executable - // but does not run it. - const main_tests = b.addTest(.{ - .root_source_file = .{ .path = "src/lib.zig" }, + // 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("zba_util", .{ + // 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/lib.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, - .optimize = optimize, }); - const run_main_tests = b.addRunArtifact(main_tests); + // 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, + }); - // This creates a build step. It will be visible in the `zig build --help` menu, - // and can be selected like this: `zig build test` - // This will evaluate the `test` step rather than the default, which is "install". - const test_step = b.step("test", "Run library tests"); - test_step.dependOn(&run_main_tests.step); + // A run step that will run the test executable. + const run_mod_tests = b.addRunArtifact(mod_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); + + // 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. } diff --git a/build.zig.zon b/build.zig.zon new file mode 100644 index 0000000..743f03d --- /dev/null +++ b/build.zig.zon @@ -0,0 +1,81 @@ +.{ + // This is the default name used by packages depending on this one. For + // example, when a user runs `zig fetch --save `, this field is used + // as the key in the `dependencies` table. Although the user can choose a + // different name, most users will stick with this provided value. + // + // It is redundant to include "zig" in this name because it is already + // within the Zig package namespace. + .name = .zba_util, + // This is a [Semantic Version](https://semver.org/). + // In a future version of Zig it will be used for package deduplication. + .version = "0.0.0", + // Together with name, this represents a globally unique package + // identifier. This field is generated by the Zig toolchain when the + // package is first created, and then *never changes*. This allows + // unambiguous detection of one package being an updated version of + // another. + // + // When forking a Zig project, this id should be regenerated (delete the + // field and run `zig build`) if the upstream project is still maintained. + // Otherwise, the fork is *hostile*, attempting to take control over the + // original project's identity. Thus it is recommended to leave the comment + // on the following line intact, so that it shows up in code reviews that + // modify the field. + .fingerprint = 0xc252e6a789d0ad48, // Changing this has security and trust implications. + // Tracks the earliest Zig version that the package considers to be a + // supported use case. + .minimum_zig_version = "0.15.1", + // This field is optional. + // Each dependency must either provide a `url` and `hash`, or a `path`. + // `zig build --fetch` can be used to fetch all dependencies of a package, recursively. + // Once all dependencies are fetched, `zig build` no longer requires + // internet connectivity. + .dependencies = .{ + // See `zig fetch --save ` for a command-line interface for adding dependencies. + //.example = .{ + // // When updating this field to a new URL, be sure to delete the corresponding + // // `hash`, otherwise you are communicating that you expect to find the old hash at + // // the new URL. If the contents of a URL change this will result in a hash mismatch + // // which will prevent zig from using it. + // .url = "https://example.com/foo.tar.gz", + // + // // This is computed from the file contents of the directory of files that is + // // obtained after fetching `url` and applying the inclusion rules given by + // // `paths`. + // // + // // This field is the source of truth; packages do not come from a `url`; they + // // come from a `hash`. `url` is just one of many possible mirrors for how to + // // obtain a package matching this `hash`. + // // + // // Uses the [multihash](https://multiformats.io/multihash/) format. + // .hash = "...", + // + // // When this is provided, the package is found in a directory relative to the + // // build root. In this case the package's hash is irrelevant and therefore not + // // computed. This field and `url` are mutually exclusive. + // .path = "foo", + // + // // When this is set to `true`, a package is declared to be lazily + // // fetched. This makes the dependency only get fetched if it is + // // actually used. + // .lazy = false, + //}, + }, + // Specifies the set of files and directories that are included in this package. + // Only files and directories listed here are included in the `hash` that + // is computed for this package. Only files listed here will remain on disk + // when using the zig package manager. As a rule of thumb, one should list + // files required for compilation plus any license(s). + // Paths are relative to the build root. Use the empty string (`""`) to refer to + // the build root itself. + // A directory listed here means that all files within, recursively, are included. + .paths = .{ + "build.zig", + "build.zig.zon", + "src", + // For example... + //"LICENSE", + //"README.md", + }, +} diff --git a/src/lib.zig b/src/lib.zig index 686543a..6e98d83 100644 --- a/src/lib.zig +++ b/src/lib.zig @@ -6,7 +6,7 @@ pub fn RingBuffer(comptime T: type) type { return struct { const Self = @This(); const Index = usize; - const max_capacity = (@as(Index, 1) << @typeInfo(Index).Int.bits - 1) - 1; // half the range of index type + const max_capacity = (@as(Index, 1) << @typeInfo(Index).int.bits - 1) - 1; // half the range of index type const log = std.log.scoped(.RingBuffer); @@ -73,20 +73,20 @@ pub fn RingBuffer(comptime T: type) type { // Sign-Extend value of type `T` to type `U` pub fn sext(comptime T: type, comptime U: type, value: T) T { // U must have less bits than T - comptime std.debug.assert(@typeInfo(U).Int.bits <= @typeInfo(T).Int.bits); + comptime std.debug.assert(@typeInfo(U).int.bits <= @typeInfo(T).int.bits); - const iT = std.meta.Int(.signed, @typeInfo(T).Int.bits); - const ExtU = if (@typeInfo(U).Int.signedness == .unsigned) T else iT; - const shift_amt: Log2Int(T) = @intCast(@typeInfo(T).Int.bits - @typeInfo(U).Int.bits); + const iT = std.meta.Int(.signed, @typeInfo(T).int.bits); + const ExtU = if (@typeInfo(U).int.signedness == .unsigned) T else iT; + const shift_amt: Log2Int(T) = @intCast(@typeInfo(T).int.bits - @typeInfo(U).int.bits); return @bitCast(@as(iT, @bitCast(@as(ExtU, @as(U, @truncate(value))) << shift_amt)) >> shift_amt); } /// See https://godbolt.org/z/W3en9Eche pub inline fn rotr(comptime T: type, x: T, r: anytype) T { - if (@typeInfo(T).Int.signedness == .signed) + if (@typeInfo(T).int.signedness == .signed) @compileError("cannot rotate signed integer"); - const ar: Log2Int(T) = @intCast(@mod(r, @typeInfo(T).Int.bits)); + const ar: Log2Int(T) = @intCast(@mod(r, @typeInfo(T).int.bits)); return x >> ar | x << (1 +% ~ar); }