[Zig] Rewrite build for Zig 0.11 (#2514)

* zig build fixes

* Disable LTO on Windows.

build.zig

@@ -1,68 +1,87 @@
+// Compatible with Zig Version 0.11.0
 const std = @import("std");
-const commit_hash = @embedFile(".git/refs/heads/master");
+const Compile = std.Build.Step.Compile;
+const ConfigHeader = std.Build.Step.ConfigHeader;
+const Mode = std.builtin.Mode;
+const CrossTarget = std.zig.CrossTarget;
 
-// Zig Version: 0.11.0-dev.3986+e05c242cd
-pub fn build(b: *std.build.Builder) void {
-    const target = b.standardTargetOptions(.{});
-    const optimize = b.standardOptimizeOption(.{});
+const Maker = struct {
+    builder: *std.build.Builder,
+    target: CrossTarget,
+    optimize: Mode,
+    config_header: *ConfigHeader,
+
+    const cflags = .{"-std=c11"};
+    const cxxflags = .{"-std=c++11"};
+
+    fn init(builder: *std.build.Builder) Maker {
+        const commit_hash = @embedFile(".git/refs/heads/master");
+        const config_header = builder.addConfigHeader(
+            .{ .style = .blank, .include_path = "build-info.h" },
+            .{
+                .BUILD_NUMBER = 0,
+                .BUILD_COMMIT = commit_hash[0 .. commit_hash.len - 1], // omit newline
+            },
+        );
+        return Maker{
+            .builder = builder,
+            .target = builder.standardTargetOptions(.{}),
+            .optimize = builder.standardOptimizeOption(.{}),
+            .config_header = config_header,
+        };
+    }
 
-    const config_header = b.addConfigHeader(
-        .{ .style = .blank, .include_path = "build-info.h" },
-        .{
-            .BUILD_NUMBER = 0,
-            .BUILD_COMMIT = commit_hash[0 .. commit_hash.len - 1], // omit newline
-        },
-    );
+    fn obj(m: *const Maker, name: []const u8, src: []const u8) *Compile {
+        const o = m.builder.addObject(.{ .name = name, .target = m.target, .optimize = m.optimize });
+        if (std.mem.endsWith(u8, src, ".c")) {
+            o.addCSourceFiles(&.{src}, &cflags);
+            o.linkLibC();
+        } else {
+            o.addCSourceFiles(&.{src}, &cxxflags);
+            o.linkLibCpp();
+        }
+        o.addIncludePath(.{ .path = "." });
+        o.addIncludePath(.{ .path = "./examples" });
+        return o;
+    }
+
+    fn exe(m: *const Maker, name: []const u8, src: []const u8, deps: []const *Compile) *Compile {
+        const e = m.builder.addExecutable(.{ .name = name, .target = m.target, .optimize = m.optimize });
+        e.addIncludePath(.{ .path = "." });
+        e.addIncludePath(.{ .path = "./examples" });
+        e.addCSourceFiles(&.{src}, &cxxflags);
+        for (deps) |d| e.addObject(d);
+        e.linkLibC();
+        e.linkLibCpp();
+        e.addConfigHeader(m.config_header);
+        m.builder.installArtifact(e);
 
-    const lib = b.addStaticLibrary(.{
-        .name = "llama",
-        .target = target,
-        .optimize = optimize,
-    });
-    lib.linkLibC();
-    lib.linkLibCpp();
-    lib.addIncludePath(".");
-    lib.addIncludePath("./examples");
-    lib.addConfigHeader(config_header);
-    lib.addCSourceFiles(&.{"ggml.c"}, &.{"-std=c11"});
-    lib.addCSourceFiles(&.{"llama.cpp"}, &.{"-std=c++11"});
-    b.installArtifact(lib);
+        // Currently a bug is preventing correct linking for optimized builds for Windows:
+        // https://github.com/ziglang/zig/issues/15958
+        if (e.target.isWindows()) {
+            e.want_lto = false;
+        }
+        return e;
+    }
+};
 
-    const examples = .{
-        "main",
-        "baby-llama",
-        "embedding",
-        "metal",
-        "perplexity",
-        "quantize",
-        "quantize-stats",
-        "save-load-state",
-        "server",
-        "simple",
-        "train-text-from-scratch",
-    };
+pub fn build(b: *std.build.Builder) void {
+    const make = Maker.init(b);
 
-    inline for (examples) |example_name| {
-        const exe = b.addExecutable(.{
-            .name = example_name,
-            .target = target,
-            .optimize = optimize,
-        });
-        exe.addIncludePath(".");
-        exe.addIncludePath("./examples");
-        exe.addConfigHeader(config_header);
-        exe.addCSourceFiles(&.{
-            std.fmt.comptimePrint("examples/{s}/{s}.cpp", .{ example_name, example_name }),
-            "examples/common.cpp",
-        }, &.{"-std=c++11"});
-        exe.linkLibrary(lib);
-        b.installArtifact(exe);
+    const ggml = make.obj("ggml", "ggml.c");
+    const ggml_alloc = make.obj("ggml-alloc", "ggml-alloc.c");
+    const llama = make.obj("llama", "llama.cpp");
+    const common = make.obj("common", "examples/common.cpp");
+    const grammar_parser = make.obj("grammar-parser", "examples/grammar-parser.cpp");
 
-        const run_cmd = b.addRunArtifact(exe);
-        run_cmd.step.dependOn(b.getInstallStep());
-        if (b.args) |args| run_cmd.addArgs(args);
+    _ = make.exe("main", "examples/main/main.cpp", &.{ ggml, ggml_alloc, llama, common, grammar_parser });
+    _ = make.exe("quantize", "examples/quantize/quantize.cpp", &.{ ggml, ggml_alloc, llama });
+    _ = make.exe("perplexity", "examples/perplexity/perplexity.cpp", &.{ ggml, ggml_alloc, llama, common });
+    _ = make.exe("embedding", "examples/embedding/embedding.cpp", &.{ ggml, ggml_alloc, llama, common });
+    _ = make.exe("train-text-from-scratch", "examples/train-text-from-scratch/train-text-from-scratch.cpp", &.{ ggml, ggml_alloc, llama });
 
-        const run_step = b.step("run-" ++ example_name, "Run the app");
-        run_step.dependOn(&run_cmd.step);
+    const server = make.exe("server", "examples/server/server.cpp", &.{ ggml, ggml_alloc, llama, common, grammar_parser });
+    if (server.target.isWindows()) {
+        server.linkSystemLibrary("ws2_32");
     }
 }