build.rs was using cfg(target) but it has to evaluate this from env TARGET
as build.rs cfg(target) in build context is the builder host and not the target.
This change fixes curve25519_dalek_bits lottery to determine the correct
automatic curve25119_dalek_bits with the help of platforms crate.
As discussed in #456 this also prepares for well known defaults for wasm and
arm serial backend via cfg(curve25519_dalek_bits = "64")
If the wasm32 or armv7 are going to be u64 serial by default these will be
followed up on later.
Crate features are intended to be additive, whereas only 1-of-N possible
backends can be selected.
Features can also be activated by transitive dependencies, which leads
to a problem of different dependences selecting conflicting backends.
Using `--cfg` instead moves all backend selection control to the
toplevel executable.
This commit switches to the following RUSTFLAGS to enable backends:
- `--cfg curve25519_dalek_backend="fiat"`: uses `fiat-crypto`
- `--cfg curve25519_dalek_backend="simd"`: uses nightly-only SIMD
* Restructure README and CHANGELOG
* Explain semver policy
* Specify feature flags and backends more explicitly
* Remove nightly from the CI bc that didn't belong there
* Add @pinkforest to thankyou list
Co-authored-by: pinkforest <36498018+pinkforest@users.noreply.github.com>
Previously `cargo test --no-default-features` would succeed but with
warnings. This commit fixes all of those warnings and tests
`--no-default-features` in CI to ensure that in perpetuity.
As suggested in #453 it is sometimes feasible to
select the backend bits via an override.
This change provides `cfg(curve25519_dalek_bits)`
to override the bits used in serial or fiat target backend.
The `RUSTFLAGS` were getting applied to build scripts, which caused them
to crash with SIGILL.
According to this issue, RUSTFLAGS won't be applied to build scripts
when cross-compiling by passing the `--target` attribute:
https://github.com/rust-lang/cargo/issues/4423
This attempts to work around the problem by explicitly passing:
--target x86_64-unknown-linux-gnu
As proposed in #414, this commit changes the backend selection approach,
introspecting `target_pointer_width` to select `u32_backend` vs
`u64_backend` (or `fiat_u32_backend`/`fiat_u64_backend` if the
`fiat_backend` feature is enabled).
This helps eliminate the use of non-additive features, and also the
rather confusing errors that happen if multiple backends are selected
(i.e. thousands of lines of rustc errors).
The selection logic checks if `target_pointer_width = "64"` and uses the
64-bit backend, or falls back to the 32-bit backend otherwise. This
means the crate will always have a valid backend regardless of the
pointer width, although there may be odd edge cases for exotic platforms
which would optimally use the 64-bit backend but have a non-"64" target
pointer width for whatever reason. We can handle those cases as they
come up.
This replaces the Travis CI workflows.
(cherry picked from commit d66a5a81f87dae29d0bb1a41bec26c57e6909c28)
Signed-off-by: Isis Lovecruft <isis@patternsinthevoid.net>
I discarded the portion of the original commit which removed TravisCI.
