build(go): cross compile

This doesn't work, because there is a bug in Zig 0.15 that produces truncated or malformed archives (fixed in Zig 0.16). There also is an error when setting -target for zig cc and zig c++.

2 files changed, 27 insertions, 14 deletions

diff --git a/build.zig b/build.zig
index a934bbc..5c08440 100644
--- a/build.zig
+++ b/build.zig
@@ -109,7 +109,7 @@ pub fn build(b: *std.Build) void {
     const example_run = b.addRunArtifact(example);
     examples_step.dependOn(&example_run.step);
 
-    const check = b.step("check", "Check if foo compiles");
+    const check = b.step("check", "Check if it compiles");
     check.dependOn(&lib.step);
 }
 
diff --git a/go/build.zig b/go/build.zig
index 6399042..4babb18 100644
--- a/go/build.zig
+++ b/go/build.zig
@@ -1,4 +1,5 @@
 const std = @import("std");
+const builtin = @import("builtin");
 
 pub fn build(b: *std.Build) !void {
     const target = b.standardTargetOptions(.{});
@@ -18,27 +19,39 @@ pub fn build(b: *std.Build) !void {
     //lib.pie = true;
     const install_lib = b.addInstallArtifact(lib, .{});
 
-    var flags = try std.ArrayList(u8).initCapacity(b.allocator, 2);
-    try flags.appendSlice(b.allocator, "-linkmode external -extldflags -static");
-    if (optimize != .Debug) try flags.appendSlice(b.allocator, " -s");
-    const go_build = b.addSystemCommand(&[_][]const u8{
-        "go",       "build",
-        "-ldflags", flags.items,
-        ".",
-    });
+    const go_build = buildGo(b, target, optimize, "build");
     go_build.step.dependOn(&install_lib.step);
     install_step.dependOn(&go_build.step);
 
     const test_step = b.step("test", "Run tests");
     test_step.dependOn(b.getInstallStep());
     const race = b.option(bool, "race", "Run tests with -race") orelse false;
-    const go_test = b.addSystemCommand(&[_][]const u8{
-        "go",       "test",
-        "-ldflags", flags.items,
-        "-v",
-    });
+    const go_test = buildGo(b, target, optimize, "test");
     if (race) go_test.addArg("-race");
     go_test.addArg("./...");
 
     test_step.dependOn(install_step);
 }
+
+fn buildGo(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, command: []const u8) *std.Build.Step.Run {
+    var flags = std.ArrayList(u8).initCapacity(b.allocator, 2) catch unreachable;
+    flags.appendSlice(b.allocator, "-linkmode external -extldflags -static") catch unreachable;
+    if (optimize != .Debug) flags.appendSlice(b.allocator, " -s") catch unreachable;
+    //const targetStr = std.fmt.allocPrint(b.allocator, "{s}-{s}-{s}", .{
+    //    @tagName(target.result.cpu.arch),
+    //    @tagName(target.result.os.tag),
+    //    @tagName(target.result.abi),
+    //}) catch unreachable;
+    //const cc = std.fmt.allocPrint(b.allocator, "zig cc -target {s}", .{targetStr}) catch unreachable;
+    //const cpp = std.fmt.allocPrint(b.allocator, "zig c++ -target {s}", .{targetStr}) catch unreachable;
+    const run = b.addSystemCommand(&[_][]const u8{
+        "go",       command,
+        "-ldflags", flags.items,
+        ".",
+    });
+    run.setEnvironmentVariable("CC", "zig cc");
+    run.setEnvironmentVariable("C++", "zig c++");
+    run.setEnvironmentVariable("CGO_ENABLED", "1");
+    run.setEnvironmentVariable("GOOS", @tagName(target.result.os.tag));
+    return run;
+}