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| author | Urgau <urgau@numericable.fr> | 2024-09-30 11:15:05 +0200 |
|---|---|---|
| committer | Urgau <urgau@numericable.fr> | 2024-09-30 11:15:05 +0200 |
| commit | 020bd6d323f20fa3c723320ee5b8484a8bcaa6cb (patch) | |
| tree | 9691199352f5206a9148c3910c0a7dcecf6ae294 | |
| parent | 2da3cb9cab706ff029ee5a40c6dee1c1f188e0bb (diff) | |
| download | rust-020bd6d323f20fa3c723320ee5b8484a8bcaa6cb.tar.gz rust-020bd6d323f20fa3c723320ee5b8484a8bcaa6cb.zip | |
Improve `--print=check-cfg` documentation
| -rw-r--r-- | src/doc/unstable-book/src/compiler-flags/print-check-cfg.md | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/src/doc/unstable-book/src/compiler-flags/print-check-cfg.md b/src/doc/unstable-book/src/compiler-flags/print-check-cfg.md index ab63c986e85..8d314aa62d4 100644 --- a/src/doc/unstable-book/src/compiler-flags/print-check-cfg.md +++ b/src/doc/unstable-book/src/compiler-flags/print-check-cfg.md @@ -4,23 +4,28 @@ The tracking issue for this feature is: [#125704](https://github.com/rust-lang/r ------------------------ -This option of the `--print` flag print the list of expected cfgs. +This option of the `--print` flag print the list of all the expected cfgs. -This is related to the `--check-cfg` flag which allows specifying arbitrary expected +This is related to the [`--check-cfg` flag][check-cfg] which allows specifying arbitrary expected names and values. -This print option works similarly to `--print=cfg` (modulo check-cfg specifics): - - *check_cfg syntax*: *output of --print=check-cfg* - - `cfg(windows)`: `windows` - - `cfg(feature, values("foo", "bar"))`: `feature="foo"` and `feature="bar"` - - `cfg(feature, values(none(), ""))`: `feature` and `feature=""` - - `cfg(feature, values(any()))`: `feature=any()` - - `cfg(feature, values())`: `feature=` - - `cfg(any())`: `any()` - - *nothing*: `any()=any()` +This print option works similarly to `--print=cfg` (modulo check-cfg specifics). + +| `--check-cfg` | `--print=check-cfg` | +|-----------------------------------|-----------------------------| +| `cfg(foo)` | `foo` | +| `cfg(foo, values("bar"))` | `foo="bar"` | +| `cfg(foo, values(none(), "bar"))` | `foo` & `foo="bar"` | +| | *check-cfg specific syntax* | +| `cfg(foo, values(any())` | `foo=any()` | +| `cfg(foo, values())` | `foo=` | +| `cfg(any())` | `any()` | +| *none* | `any()=any()` | To be used like this: ```bash rustc --print=check-cfg -Zunstable-options lib.rs ``` + +[check-cfg]: https://doc.rust-lang.org/nightly/rustc/check-cfg.html |