Move protocol scanning to build.zig

1 files changed, 67 insertions, 4 deletions

diff --git a/build.zig b/build.zig
index a1f7c78..4330349 100644
--- a/build.zig
+++ b/build.zig
@@ -1,6 +1,6 @@
-const Builder = @import("std").build.Builder;
+const std = @import("std");
 
-pub fn build(b: *Builder) void {
+pub fn build(b: *std.build.Builder) !void {
     // Standard target options allows 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
@@ -11,13 +11,17 @@ pub fn build(b: *Builder) void {
     // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
     const mode = b.standardReleaseOptions();
 
+    const scan_protocols = ScanProtocolsStep.create(b);
+
     const exe = b.addExecutable("river", "src/main.zig");
     exe.setTarget(target);
     exe.setBuildMode(mode);
 
-    exe.addIncludeDir(".");
+    exe.step.dependOn(&scan_protocols.step);
     exe.addIncludeDir("protocol");
+
     exe.addCSourceFile("include/render.c", &[_][]const u8{"-std=c99"});
+    exe.addIncludeDir(".");
 
     exe.linkLibC();
     exe.linkSystemLibrary("wayland-server");
@@ -36,9 +40,11 @@ pub fn build(b: *Builder) void {
     test_exe.setTarget(target);
     test_exe.setBuildMode(mode);
 
-    test_exe.addIncludeDir(".");
+    test_exe.step.dependOn(&scan_protocols.step);
     test_exe.addIncludeDir("protocol");
+
     test_exe.addCSourceFile("include/render.c", &[_][]const u8{"-std=c99"});
+    test_exe.addIncludeDir(".");
 
     test_exe.linkLibC();
     test_exe.linkSystemLibrary("wayland-server");
@@ -48,3 +54,60 @@ pub fn build(b: *Builder) void {
     const test_step = b.step("test", "Run the tests");
     test_step.dependOn(&test_exe.step);
 }
+
+const ScanProtocolsStep = struct {
+    builder: *std.build.Builder,
+    step: std.build.Step,
+
+    fn create(builder: *std.build.Builder) *ScanProtocolsStep {
+        const self = builder.allocator.create(ScanProtocolsStep) catch unreachable;
+        self.* = init(builder);
+        return self;
+    }
+
+    fn init(builder: *std.build.Builder) ScanProtocolsStep {
+        return ScanProtocolsStep{
+            .builder = builder,
+            .step = std.build.Step.init("Scan Protocols", builder.allocator, make),
+        };
+    }
+
+    fn make(step: *std.build.Step) !void {
+        const self = @fieldParentPtr(ScanProtocolsStep, "step", step);
+
+        const protocol_dir = std.fmt.trim(try self.builder.exec(
+            &[_][]const u8{ "pkg-config", "--variable=pkgdatadir", "wayland-protocols" },
+        ));
+
+        const protocol_dir_paths = [_][]const []const u8{
+            &[_][]const u8{ protocol_dir, "stable/xdg-shell/xdg-shell.xml" },
+            &[_][]const u8{ "protocol", "wlr-layer-shell-unstable-v1.xml" },
+        };
+
+        for (protocol_dir_paths) |dir_path| {
+            const xml_in_path = try std.fs.path.join(self.builder.allocator, dir_path);
+
+            // Extension is .xml, so slice off the last 4 characters
+            const basename = std.fs.path.basename(xml_in_path);
+            const basename_no_ext = basename[0..(basename.len - 4)];
+
+            const header_out_path = try std.mem.concat(
+                self.builder.allocator,
+                u8,
+                &[_][]const u8{ "protocol/", basename_no_ext, "-protocol.h" },
+            );
+            const code_out_path = try std.mem.concat(
+                self.builder.allocator,
+                u8,
+                &[_][]const u8{ "protocol/", basename_no_ext, "-protocol.c" },
+            );
+
+            _ = try self.builder.exec(
+                &[_][]const u8{ "wayland-scanner", "server-header", xml_in_path, header_out_path },
+            );
+            _ = try self.builder.exec(
+                &[_][]const u8{ "wayland-scanner", "private-code", xml_in_path, code_out_path },
+            );
+        }
+    }
+};