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@ -2,40 +2,27 @@
# Bazel zig cc toolchain for Go
This is a prototype zig-cc toolchain that can compile cgo programs with these c
libraries:
This is a prototype zig-cc toolchain that can cross-compile cgo programs to these os/archs:
- glibc 2.19
- musl
- x86_64-linux-musl
- x86_64-linux-gnu.2.19
- aarch-linux-musl
- aarch-linux-gnu.2.19
- x86_64-macos
- aarch64-macos
glibc 2.19 is the default. That means, glibc 2.19 toolchain is registered with
these basic constraints:
```
[
"@platforms//os:linux",
"@platforms//cpu:x86_64",
]
```
Convenient way is still being researched (see Known Issues below).
# Testing
## linux cgo + glibc 2.19
Using the default toolchain:
Glibc toolchain is suffixed with `-gnu`:
```
$ bazel build --toolchain_resolution_debug=true //test:gognu
...
$ ../bazel-bin/test/gognu_/gognu
hello, world
$ file ../bazel-bin/test/gognu_/gognu
../bazel-bin/test/gognu_/gognu: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.0.0, Go BuildID=redacted, with debug_info, not stripped
```
Explicitly the toolchain explicitly `-gnu`:
```
$ bazel run --platforms @zig_sdk//:x86_64-linux-gnu //test:gognu
$ file bazel-bin/test/gognu_/gognu
bazel-bin/test/gognu_/gognu: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.0.0, Go BuildID=redacted, with debug_info, not stripped
```
## linux cgo + musl
@ -49,13 +36,13 @@ $ ../bazel-out/k8-fastbuild-ST-d17813c235ce/bin/test/gomusl_/gomusl
hello, world
```
## macos cgo + gnu
Does not work?
## macos cgo
```
$ bazel build --platforms @zig_sdk//:x86_64-macos-musl //test:gognu
$ bazel build --platforms @zig_sdk//:x86_64-macos-gnu //test:gognu
...
$ file bazel-bin/test/gognu_/gognu
bazel-bin/test/gognu_/gognu: Mach-O 64-bit x86_64 executable, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL|PIE>
```
## Transient docker environment
@ -69,20 +56,12 @@ $ docker run -ti --rm -v $(pwd):/x -w /x debian:buster-slim
And run the `bazel build` commands above. Take a look at `.build.yml` and see
how CI does it.
# Appendix: compiling manually
zcc
```
#!/bin/bash
exec zig cc -target x86_64-macos-gnu "$@"
```
Build:
```
GOOS=darwin GOARCH=amd64 CC=zcc go build -ldflags "-linkmode external -extldflags -static" hello.go
```
# Known Issues
- [ziglang/zig #9139 zig c++ hanging when compiling golang for macos](https://github.com/ziglang/zig/issues/9139).
- [rules/go #2894 Per-arch_target linker flags #2894 ](https://github.com/bazelbuild/rules_go/issues/2894).
Closed issues:
- [golang/go #46644: cmd/link: with CC=zig: SIGSERV when cross-compiling to darwin/amd64](https://github.com/golang/go/issues/46644) (CLOSED)
- [ziglang/zig #9050 golang linker segfault](https://github.com/ziglang/zig/issues/9050)
- [ziglang/zig #9050 golang linker segfault](https://github.com/ziglang/zig/issues/9050) (CLOSED)