C++ Module: zig c++ does not support

[kassane]

Zig toolchain for C & C++ projects is based on presenting pure LLVM build tools (clang/++ + lld + libcxx).
Previously tried some tests of C++ module using zig in addition to switching C++ ABI (LLVM to GNU).

See: https://github.com/kassane/fmt/actions/runs/4773408799

cc: @vitaut @DanielaE

References:

• zig run/cc: recognize "-x language" ziglang/zig#13544 missing -x c++module.
• https://gist.github.com/kassane/7e9a2da137e13eb6e1dbab726693bdb7 (c++ modules tests w/ zig)

[DanielaE]

Correct. Clang doesn't recognize .cc as a valid extension for module TUs and requires help by -x c++-module.

My collective knowledge about modules and {fmt} can be found here on my module testing branch

[kassane]

Nice!

My test on your testing-branch:

$> zig build -DTests

zig build-exe module-test Debug native: error: error(compilation): clang failed with stderr: /home/kassane/fmt_modules/test/module-test.cc:47:8: fatal error: module 'fmt' not found

zig build-exe module-test Debug native: error: the following command failed with 1 compilation errors:
/home/kassane/zig/0.11.0-dev.2868+1a455b2dd/files/zig build-exe -cflags -std=c++2b -- /home/kassane/fmt_modules/test/module-test.cc -cflags -Wall -Wextra -Wno-deprecated-declarations -- /home/kassane/fmt_modules/test/gtest/gmock-gtest-all.cc /home/kassane/fmt_modules/test/gtest-extra.cc /home/kassane/fmt_modules/test/enforce-checks-test.cc /home/kassane/fmt_modules/test/util.cc /home/kassane/fmt_modules/zig-cache/o/16ac77627b4f5a43a413bfb9de2c9425/libfmt.a -lc++ --cache-dir /home/kassane/fmt_modules/zig-cache --global-cache-dir /home/kassane/.cache/zig --name module-test -I /home/kassane/fmt_modules/include -I /home/kassane/fmt_modules/test -I /home/kassane/fmt_modules/test/gtest -I /home/kassane/fmt_modules/zig-out/include -D _SILENCE_TR1_NAMESPACE_DEPRECATION_WARNING=1 -D GTEST_HAS_PTHREAD=0 --listen=-
Build Summary: 39/42 steps succeeded; 1 failed (disable with -fno-summary)
install transitive failure
├─ install include/ cached
├─ install fmt cached
│  └─ zig build-lib fmt Debug native cached 8ms MaxRSS:34M
├─ install args-test cached
│  └─ zig build-exe args-test Debug native cached 10ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install core-test cached
│  └─ zig build-exe core-test Debug native cached 1s MaxRSS:32M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install unicode-test cached
│  └─ zig build-exe unicode-test Debug native cached 11ms MaxRSS:33M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install assert-test cached
│  └─ zig build-exe assert-test Debug native cached 11ms MaxRSS:33M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install std-test cached
│  └─ zig build-exe std-test Debug native cached 12ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install xchar-test cached
│  └─ zig build-exe xchar-test Debug native cached 11ms MaxRSS:33M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install ostream-test cached
│  └─ zig build-exe ostream-test Debug native cached 13ms MaxRSS:33M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install printf-test cached
│  └─ zig build-exe printf-test Debug native cached 16ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install scan-test cached
│  └─ zig build-exe scan-test Debug native cached 12ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install ranges-test cached
│  └─ zig build-exe ranges-test Debug native cached 12ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install color-test cached
│  └─ zig build-exe color-test Debug native cached 12ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install chrono-test cached
│  └─ zig build-exe chrono-test Debug native cached 13ms MaxRSS:33M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install compile-test cached
│  └─ zig build-exe compile-test Debug native cached 13ms MaxRSS:33M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install compile-fp-test cached
│  └─ zig build-exe compile-fp-test Debug native cached 12ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install format-test cached
│  └─ zig build-exe format-test Debug native cached 11ms MaxRSS:32M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install os-test cached
│  └─ zig build-exe os-test Debug native cached 12ms MaxRSS:34M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install noexception-test cached
│  └─ zig build-exe noexception-test Debug native cached 17ms MaxRSS:32M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
├─ install posix-mock-test cached
│  └─ zig build-exe posix-mock-test Debug native cached 1s MaxRSS:33M
│     ├─ zig build-lib fmt Debug native (reused)
│     └─ install include/ (reused)
└─ install module-test transitive failure
   └─ zig build-exe module-test Debug native 1 errors
      ├─ zig build-lib fmt Debug native (reused)
      └─ install include/ (reused)

# zig v0.11.0-dev/master is LLVM 16.0.1

$> zig cc -x c++ -std=c++2b -Iinclude test/module-test.cc -o module -lc++ -Lzig-out/lib -lfmt
test/module-test.cc:47:8: fatal error: module 'fmt' not found
import fmt;
~~~~~~~^~~
1 error generated.

$>  zig cc -x c++-module -std=c++2b -Iinclude test/module-test.cc -o module -lc++ -Lzig-out/lib -lfmt
error: language not recognized: 'c++-module'

Edit: missing --precompile, but still not resolved.

I'll fork zig toolchain to add -x c++-module.
Utilizing your branch as test base!

thank you for the feedback!