register only gnu toolchain by default

musl can be specified with --extra_toolchains.

.bazelversion

@@ -0,0 +1 @@
+4.1.0

.build.yml

@@ -12,36 +12,36 @@ tasks:
       curl -L https://github.com/bazelbuild/bazelisk/releases/download/v1.9.0/bazelisk-linux-amd64 \
         -o bazel
       chmod +x bazel
-  #- test_default: |
-  #    cd bazel-zig-cc; ../bazel run \
-  #      //test:gognu
+  - test_default: |
+      cd bazel-zig-cc; ../bazel run \
+        //test:hello
   - test_x86_64-linux-gnu: |
       cd bazel-zig-cc; ../bazel run \
-           --platforms @zig_sdk//:x86_64-linux-gnu //test:gognu
-      file $(./getpath @zig_sdk//:x86_64-linux-gnu //test:gognu) | \
+           --platforms @zig_sdk//:x86_64-linux-gnu //test:hello
+      file $(./getpath @zig_sdk//:x86_64-linux-gnu //test:hello) | \
         tee /dev/stderr | grep -q "ELF 64-bit.* x86-64.* dynamically linked"
   - test_x86_64-linux-musl: |
       cd bazel-zig-cc; ../bazel run \
-           --platforms @zig_sdk//:x86_64-linux-musl //test:gomusl
-      file $(./getpath @zig_sdk//:x86_64-linux-musl //test:gomusl) | \
+           --platforms @zig_sdk//:x86_64-linux-musl //test:hello
+      file $(./getpath @zig_sdk//:x86_64-linux-musl //test:hello) | \
         tee /dev/stderr | grep -q "ELF 64-bit.* x86-64.* statically linked"
   - test_aarch64-linux-gnu: |
       cd bazel-zig-cc; ../bazel build \
-           --platforms @zig_sdk//:aarch64-linux-gnu //test:gognu
-      file $(./getpath @zig_sdk//:aarch64-linux-gnu //test:gognu) | \
+           --platforms @zig_sdk//:aarch64-linux-gnu //test:hello
+      file $(./getpath @zig_sdk//:aarch64-linux-gnu //test:hello) | \
         tee /dev/stderr | grep -q "ELF 64-bit.* ARM aarch64.* dynamically linked"
   - test_aarch64-linux-musl: |
       cd bazel-zig-cc; ../bazel build \
-           --platforms @zig_sdk//:aarch64-linux-musl //test:gomusl
-      file $(./getpath @zig_sdk//:aarch64-linux-musl //test:gomusl) | \
+           --platforms @zig_sdk//:aarch64-linux-musl //test:hello
+      file $(./getpath @zig_sdk//:aarch64-linux-musl //test:hello) | \
         tee /dev/stderr | grep -q "ELF 64-bit.* ARM aarch64.* statically linked"
   - test_x86_64-macos-gnu: |
       cd bazel-zig-cc; ../bazel build \
-        --platforms @zig_sdk//:x86_64-macos-gnu //test:gognu
-      file $(./getpath @zig_sdk//:x86_64-macos-gnu //test:gognu) | \
+        --platforms @zig_sdk//:x86_64-macos-gnu //test:hello
+      file $(./getpath @zig_sdk//:x86_64-macos-gnu //test:hello) | \
         tee /dev/stderr | grep -q "Mach-O 64-bit x86_64 executable"
   - test_aarch64-macos-gnu: |
       cd bazel-zig-cc; ../bazel build \
-        --platforms @zig_sdk//:aarch64-macos-gnu //test:gognu
-      file $(./getpath @zig_sdk//:aarch64-macos-gnu //test:gognu) | \
+        --platforms @zig_sdk//:aarch64-macos-gnu //test:hello
+      file $(./getpath @zig_sdk//:aarch64-macos-gnu //test:hello) | \
         tee /dev/stderr | grep -q "Mach-O 64-bit arm64 executable"

.gitignore

@@ -2,7 +2,8 @@
 *.sw[op]
 
 /bazel
-/bazel-bin
 /bazel-bazel-zig-cc
+/bazel-bin
 /bazel-out
 /bazel-testlogs
+/bazel-x

README.md

@@ -28,11 +28,11 @@ bazel-bin/test/gognu_/gognu: ELF 64-bit LSB executable, x86-64, version 1 (SYSV)
 ## linux cgo + musl
 
 ```
-$ bazel build --platforms @zig_sdk//:x86_64-linux-musl //test:gomusl
+$ bazel build --extra_toolchains @zig_sdk//:x86_64-linux-musl_toolchain //test:hello
 ...
-$ file ../bazel-out/k8-fastbuild-ST-d17813c235ce/bin/test/gomusl_/gomusl
-../bazel-out/k8-fastbuild-ST-d17813c235ce/bin/test/gomusl_/gomusl: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, Go BuildID=redacted, with debug_info, not stripped
-$ ../bazel-out/k8-fastbuild-ST-d17813c235ce/bin/test/gomusl_/gomusl
+$ file ../bazel-out/k8-fastbuild-ST-d17813c235ce/bin/test/hello_/hello
+../bazel-out/k8-fastbuild-ST-d17813c235ce/bin/test/hello_/hello: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, Go BuildID=redacted, with debug_info, not stripped
+$ ../bazel-out/k8-fastbuild-ST-d17813c235ce/bin/test/hello_/hello
 hello, world
 ```
 

test/BUILD

@@ -1,7 +1,7 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 
 go_library(
-    name = "go_lib",
+    name = "hello_lib",
     srcs = ["hello.go"],
     cgo = True,
     importpath = "github.com/motiejus/bazel-zig-cc/test",
@@ -9,22 +9,16 @@ go_library(
 )
 
 go_binary(
-    name = "gognu",
-    embed = [":go_lib"],
+    name = "hello",
+    embed = [":hello_lib"],
     gc_linkopts = select({
-        "@platforms//os:macos": ["-s", "-w", "-buildmode=pie"],
+        "@platforms//os:macos": [
+            "-s",
+            "-w",
+            "-buildmode=pie",
+        ],
         "//conditions:default": [],
     }),
-    visibility = ["//visibility:public"],
-)
-
-go_binary(
-    name = "gomusl",
-    embed = [":go_lib"],
     static = "on",
-    target_compatible_with = select({
-        "@platforms//os:linux": ["@zig_sdk//:libc_musl"],
-        "//conditions:default": [],
-    }),
     visibility = ["//visibility:public"],
 )

toolchain/defs.bzl

@@ -53,7 +53,6 @@ TARGET_CONFIGS_LISTOFLISTS = [[
         constraint_values = [
             "@platforms//os:linux",
             "@platforms//cpu:{}".format(cpu),
-            ":libc_gnu",
         ],
         tool_paths = {"ld": "ld.lld"},
     ),
@@ -71,9 +70,9 @@ TARGET_CONFIGS_LISTOFLISTS = [[
         constraint_values = [
             "@platforms//os:linux",
             "@platforms//cpu:{}".format(cpu),
-            ":libc_musl",
         ],
         tool_paths = {"ld": "ld.lld"},
+        skip_register = True,
     ),
 ] for cpu in ("x86_64", "aarch64")]
 
@@ -101,9 +100,10 @@ def toolchain_repositories():
 
 def register_all_toolchains():
     for target_config in TARGET_CONFIGS:
-        native.register_toolchains(
-            "@zig_sdk//:%s_toolchain" % target_config.target,
-        )
+        if not getattr(target_config, "skip_register", False):
+            native.register_toolchains(
+                "@zig_sdk//:%s_toolchain" % target_config.target,
+            )
 
 ZIG_TOOL_PATH = "tools/{zig_tool}"
 ZIG_TOOL_WRAPPER = """#!/bin/bash
@@ -188,18 +188,6 @@ def zig_build_macro(absolute_path, zig_include_root):
     filegroup(name = "zig_compiler", srcs = ["zig"])
     filegroup(name = "lib/std", srcs = native.glob(["lib/std/**"]))
 
-    native.constraint_setting(name = "libc")
-
-    native.constraint_value(
-        name = "libc_musl",
-        constraint_setting = ":libc",
-    )
-
-    native.constraint_value(
-        name = "libc_gnu",
-        constraint_setting = ":libc",
-    )
-
     lazy_filegroups = {}
 
     for target_config in TARGET_CONFIGS: