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Diffstat (limited to 'src/doc/rustc')
| -rw-r--r-- | src/doc/rustc/src/targets/custom.md | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/doc/rustc/src/targets/custom.md b/src/doc/rustc/src/targets/custom.md index 6c1494186a4..e1750e27f0b 100644 --- a/src/doc/rustc/src/targets/custom.md +++ b/src/doc/rustc/src/targets/custom.md @@ -16,6 +16,21 @@ rustc +nightly -Z unstable-options --target=wasm32-unknown-unknown --print targe To use a custom target, see the (unstable) [`build-std` feature](../../cargo/reference/unstable.html#build-std) of `cargo`. +<div class="warning"> + +The target JSON properties are not stable and subject to change. +Always pin your compiler version when using custom targets! + +</div> + +## JSON Schema + +`rustc` provides a JSON schema for the custom target JSON specification. +Because the schema is subject to change, you should always use the schema from the version of rustc which you are passing the target to. + +It can be found in `etc/target-spec-json-schema.json` in the sysroot (`rustc --print sysroot`) or printed with `rustc +nightly -Zunstable-options --print target-spec-json-schema`. +The existence and name of this schema is, just like the properties of the JSON specification, not stable and subject to change. + ## Custom Target Lookup Path When `rustc` is given an option `--target=TARGET` (where `TARGET` is any string), it uses the following logic: |