AT_HWCAP2 not always defined

justsmth commented 1 week ago

Issues:

Addresses: https://github.com/aws/aws-lc-rs/issues/427

Description of changes:

Allow fallback when AT_HWCAP2 is not defined (for older glibc).

  AT_HWCAP2 (since glibc 2.18)
         Further machine-dependent hints about processor
         capabilities.

Testing:

I've not yet been able to setup an environment that replicates the failure seen downstream for arm-unknown-linux-gnueabihf:

In file included from /cargo/registry/src/index.crates.io-6f17d22bba15001f/aws-lc-sys-0.18.0/aws-lc/crypto/fipsmodule/bcm.c:81:
/cargo/registry/src/index.crates.io-6f17d22bba15001f/aws-lc-sys-0.18.0/aws-lc/crypto/fipsmodule/cpucap/cpu_arm_linux.c: In function 'aws_lc_0_18_0_OPENSSL_cpuid_setup':
/cargo/registry/src/index.crates.io-6f17d22bba15001f/aws-lc-sys-0.18.0/aws-lc/crypto/fipsmodule/cpucap/cpu_arm_linux.c:121:38: error: 'AT_HWCAP2' undeclared (first use in this function); did you mean 'AT_HWCAP'?
   unsigned long hwcap2 = getauxval(AT_HWCAP2);
                                    ^~~~~~~~~
                                    AT_HWCAP
/cargo/registry/src/index.crates.io-6f17d22bba15001f/aws-lc-sys-0.18.0/aws-lc/crypto/fipsmodule/cpucap/cpu_arm_linux.c:121:38: note: each undeclared identifier is reported only once for each function it appears in
/cargo/registry/src/index.crates.io-6f17d22bba15001f/aws-lc-sys-0.18.0/aws-lc/crypto/fipsmodule/bcm.c: At top level:
cc1: error: unrecognized command line option '-Wno-c11-extensions' [-Werror]
cc1: all warnings being treated as errors
ninja: build stopped: subcommand failed.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.

codecov-commenter commented 1 week ago

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 78.25%. Comparing base (ba94617) to head (abe2889).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1682 +/- ## ========================================== - Coverage 78.28% 78.25% -0.04% ========================================== Files 567 567 Lines 95237 95237 Branches 13671 13671 ========================================== - Hits 74561 74525 -36 - Misses 20082 20115 +33 - Partials 594 597 +3 ```

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justsmth commented 1 week ago

Just to double check, should we handle this case for other platforms as well if applicable?

Good point. I updated the PR to also handle this case for FreeBSD and ppc64le.

aws / aws-lc