configure: Use CARGO_CFG_*_{F16,F128} rather than invoking rustc
#1003
+10
−47
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Currently we run the `rustc` from the `RUSTC` environment variable to
figure out whether or not to enable `f16` and `f128`, based on the
`target_has_reliable_{f16,f128}` config. However, this does not know
about the codegen backend used, and the backend isn't trivial to check
in a build script (usually it gets set via `RUSTFLAGS`).
It turns out we don't actually need to run `rustc` here: Cargo
unconditionally emits all config from the relevant compiler as
`CARGO_CFG_*` variables, regardless of whether or not they are known
options. Switch to checking these for setting config rather than
invoking `rustc`.
As an added advantage, this will work with target.json files without any
special handling.
Fixes: ed17b95 ("Use the compiler to determine whether or not to enable `f16` and `f128`")
tgross35
force-pushed
the
cargo-rustc-fix
branch
from
f13f9eb to
87a66ec
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Currently we run
rustcfrom theRUSTCenvironment variable to figure out whether or not to enablef16andf128, based on thetarget_has_reliable_{f16,f128}config. However, this does not know about the codegen backend used, and the backend isn't trivial to check in a build script (usually the backend gets set viaRUSTFLAGS).It turns out we don't actually need to run
rustchere: Cargo unconditionally emits all config from the relevant compiler asCARGO_CFG_*variables, regardless of whether or not they are known options. Switch to checking these to set config rather than invokingrustc.As an added advantage, we don't need any special handling for target.json files.
Fixes: ed17b95 ("Use the compiler to determine whether or not to enable
f16andf128")