fix: #217

Author: jinzhongjia

course/code/12/import_dependency_build/build.zig

@@ -0,0 +1,63 @@
+const std = @import("std");
+const ChildProcess = std.process.Child;
+
+const args = [_][]const u8{ "zig", "build" };
+
+pub fn build(b: *std.Build) !void {
+    const full_path = try std.process.getCwdAlloc(b.allocator);
+
+    var dir = std.fs.openDirAbsolute(full_path, .{ .iterate = true }) catch |err| {
+        std.log.err("open path failed {s}, err is {}", .{ full_path, err });
+        std.process.exit(1);
+    };
+    defer dir.close();
+
+    var iterate = dir.iterate();
+
+    while (iterate.next()) |val| {
+        if (val) |entry| {
+            // get the entry name, entry can be file or directory
+            const name = entry.name;
+            if (entry.kind == .directory) {
+                if (eqlu8(name, ".zig-cache") or eqlu8(name, "zig-out") or eqlu8(name, "zig-cache"))
+                    continue;
+
+                // build child process
+                var child = ChildProcess.init(&args, b.allocator);
+
+                // build cwd
+                const cwd = std.fs.path.join(b.allocator, &[_][]const u8{
+                    full_path,
+                    name,
+                }) catch |err| {
+                    std.log.err("fmt path failed, err is {}", .{err});
+                    std.process.exit(1);
+                };
+
+                // open entry dir
+                const entry_dir = std.fs.openDirAbsolute(cwd, .{}) catch unreachable;
+                entry_dir.access("build.zig", .{}) catch {
+                    std.log.err("not found build.zig in path {s}", .{cwd});
+                    std.process.exit(1);
+                };
+
+                // set child cwd
+                // this api maybe changed in the future
+                child.cwd = cwd;
+
+                // spawn and wait child process
+                _ = child.spawnAndWait() catch unreachable;
+            }
+        } else {
+            // Stop endless loop
+            break;
+        }
+    } else |err| {
+        std.log.err("iterate examples_path failed, err is {}", .{err});
+        std.process.exit(1);
+    }
+}
+
+fn eqlu8(a: []const u8, b: []const u8) bool {
+    return std.mem.eql(u8, a, b);
+}

course/code/12/import_dependency_build/pkg1/build.zig

@@ -0,0 +1,5 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    @import("pkg2").helperFunction(b);
+}

course/code/12/import_dependency_build/pkg1/build.zig.zon

@@ -0,0 +1,14 @@
+.{
+    .name = "pkg1",
+    .version = "0.0.0",
+    .dependencies = .{
+        .pkg2 = .{
+            // path 为本地包的路径
+            .path = "../pkg2",
+        },
+    },
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+    },
+}

course/code/12/import_dependency_build/pkg2/build.zig

@@ -0,0 +1,9 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    _ = b;
+}
+
+pub fn helperFunction(artifact: *std.Build) void {
+    _ = artifact;
+}

course/code/12/import_dependency_build/pkg2/build.zig.zon

@@ -0,0 +1,9 @@
+.{
+    .name = "pkg2",
+    .version = "0.0.0",
+    .dependencies = .{},
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+    },
+}

course/code/14/import_dependency_build/build.zig

@@ -0,0 +1,63 @@
+const std = @import("std");
+const ChildProcess = std.process.Child;
+
+const args = [_][]const u8{ "zig", "build" };
+
+pub fn build(b: *std.Build) !void {
+    const full_path = try std.process.getCwdAlloc(b.allocator);
+
+    var dir = std.fs.openDirAbsolute(full_path, .{ .iterate = true }) catch |err| {
+        std.log.err("open path failed {s}, err is {}", .{ full_path, err });
+        std.process.exit(1);
+    };
+    defer dir.close();
+
+    var iterate = dir.iterate();
+
+    while (iterate.next()) |val| {
+        if (val) |entry| {
+            // get the entry name, entry can be file or directory
+            const name = entry.name;
+            if (entry.kind == .directory) {
+                if (eqlu8(name, ".zig-cache") or eqlu8(name, "zig-out") or eqlu8(name, "zig-cache"))
+                    continue;
+
+                // build child process
+                var child = ChildProcess.init(&args, b.allocator);
+
+                // build cwd
+                const cwd = std.fs.path.join(b.allocator, &[_][]const u8{
+                    full_path,
+                    name,
+                }) catch |err| {
+                    std.log.err("fmt path failed, err is {}", .{err});
+                    std.process.exit(1);
+                };
+
+                // open entry dir
+                const entry_dir = std.fs.openDirAbsolute(cwd, .{}) catch unreachable;
+                entry_dir.access("build.zig", .{}) catch {
+                    std.log.err("not found build.zig in path {s}", .{cwd});
+                    std.process.exit(1);
+                };
+
+                // set child cwd
+                // this api maybe changed in the future
+                child.cwd = cwd;
+
+                // spawn and wait child process
+                _ = child.spawnAndWait() catch unreachable;
+            }
+        } else {
+            // Stop endless loop
+            break;
+        }
+    } else |err| {
+        std.log.err("iterate examples_path failed, err is {}", .{err});
+        std.process.exit(1);
+    }
+}
+
+fn eqlu8(a: []const u8, b: []const u8) bool {
+    return std.mem.eql(u8, a, b);
+}

course/code/14/import_dependency_build/pkg1/build.zig

@@ -0,0 +1,5 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    @import("pkg2").helperFunction(b);
+}

course/code/14/import_dependency_build/pkg1/build.zig.zon

@@ -0,0 +1,14 @@
+.{
+    .name = "pkg1",
+    .version = "0.0.0",
+    .dependencies = .{
+        .pkg2 = .{
+            // path 为本地包的路径
+            .path = "../pkg2",
+        },
+    },
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+    },
+}

course/code/14/import_dependency_build/pkg2/build.zig

@@ -0,0 +1,9 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    _ = b;
+}
+
+pub fn helperFunction(artifact: *std.Build) void {
+    _ = artifact;
+}

course/code/14/import_dependency_build/pkg2/build.zig.zon

@@ -0,0 +1,9 @@
+.{
+    .name = "pkg2",
+    .version = "0.0.0",
+    .dependencies = .{},
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+    },
+}

course/engineering/build-system.md

@@ -180,6 +180,24 @@ zig 本身提供了一个实验性的文档生成器，它支持搜索查询，
 
 ## 高级功能
 
+### 引用依赖中的 `build.zig`
+
+该特性自 `0.11` 引入，允许包引用依赖的 `build.zig` 中提供的一些函数，示例如下：
+
+`pkg1` 的源代码部分：
+
+::: code-group
+<<<@/code/release/import_dependency_build/pkg1/build.zig
+<<<@/code/release/import_dependency_build/pkg1/build.zig.zon{zig}
+:::
+
+`pkg2` 的源代码部分：
+
+::: code-group
+<<<@/code/release/import_dependency_build/pkg2/build.zig
+<<<@/code/release/import_dependency_build/pkg2/build.zig.zon{zig}
+:::
+
 ### 交叉编译
 
 得益于 LLVM 的存在，zig 支持交叉编译到任何 LLVM 的目标代码，zig 可以很方便的处理交叉编译，只需要指定好恰当的 target 即可。