detect: Remove last use of is_aarch64_feature_detected

Author: taiki-e

.cirrus.yml

@@ -12,20 +12,18 @@ env:
   RUSTFLAGS: -D warnings
   RUSTUP_MAX_RETRIES: '10'
 
-aarch64_linux_test_task:
+aarch64_linux_gnu_test_task:
+  env:
+    TARGET: aarch64-unknown-linux-gnu
   matrix:
     - name: test ($TARGET)
-      env:
-        TARGET: aarch64-unknown-linux-gnu
       arm_container:
         image: rust:latest
       setup_script:
         - set -ex
         - lscpu
         - rustup toolchain add nightly --no-self-update --component rust-src && rustup default nightly
     - name: test ($TARGET, glibc 2.17)
-      env:
-        TARGET: aarch64-unknown-linux-gnu
       arm_container:
         # glibc 2.17 is the minimum glibc version that aarch64 support is available: https://sourceware.org/legacy-ml/libc-announce/2012/msg00001.html
         image: centos:7
@@ -34,16 +32,6 @@ aarch64_linux_test_task:
         - lscpu
         - yum install -y gcc git
         - curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal --default-toolchain nightly --component rust-src
-    - name: test ($TARGET)
-      env:
-        TARGET: aarch64-unknown-linux-musl
-      arm_container:
-        image: rust:alpine
-      setup_script:
-        - set -ex
-        - apk --no-cache add bash git musl-dev util-linux
-        - lscpu
-        - rustup toolchain add nightly --no-self-update --component rust-src && rustup default nightly
   test_script:
     - |
       [ ! -f $HOME/.cargo/env ] || . $HOME/.cargo/env
@@ -54,6 +42,27 @@ aarch64_linux_test_task:
     # FEAT_LSE2 is tested on aarch64 macOS VM.
     - RUSTFLAGS="$RUSTFLAGS -C target-feature=+lse" RUSTDOCFLAGS="$RUSTDOCFLAGS -C target-feature=+lse" ./tools/test.sh -vv
 
+aarch64_linux_musl_test_task:
+  name: test ($TARGET)
+  env:
+    TARGET: aarch64-unknown-linux-musl
+  arm_container:
+    image: rust:alpine
+  setup_script:
+    - set -ex
+    - apk --no-cache add bash git musl-dev util-linux
+    - lscpu
+    - rustup toolchain add nightly --no-self-update --component rust-src && rustup default nightly
+  test_script:
+    - set -ex
+    - ./tools/test.sh -vv
+    # -crt-static
+    - RUSTFLAGS="$RUSTFLAGS -C target-feature=-crt-static" RUSTDOCFLAGS="$RUSTDOCFLAGS -C target-feature=-crt-static" ./tools/test.sh -vv
+    # +lse
+    # Graviton2 (Neoverse N1) is ARMv8.2-a and doesn't support FEAT_LSE2.
+    # FEAT_LSE2 is tested on aarch64 macOS VM.
+    - RUSTFLAGS="$RUSTFLAGS -C target-feature=+lse" RUSTDOCFLAGS="$RUSTDOCFLAGS -C target-feature=+lse" ./tools/test.sh -vv
+
 armel_linux_test_task:
   name: test ($TARGET)
   env:

.github/.cspell/organization-dictionary.txt

@@ -61,6 +61,7 @@ musleabi
 musleabihf
 newlibeabihf
 nvptx
+ohos
 openwrt
 riscv
 softfloat

.github/workflows/ci.yml

@@ -166,6 +166,12 @@ jobs:
         if: startsWith(matrix.rust, 'nightly') && !startsWith(matrix.os, 'windows')
 
       - run: tools/test.sh -vv $TARGET $DOCTEST_XCOMPILE $BUILD_STD
+      # -crt-static
+      - run: tools/test.sh -vv $TARGET $DOCTEST_XCOMPILE $BUILD_STD
+        env:
+          RUSTDOCFLAGS: ${{ env.RUSTDOCFLAGS }} -C target-feature=-crt-static
+          RUSTFLAGS: ${{ env.RUSTFLAGS }} -C target-feature=-crt-static
+        if: contains(matrix.target, '-musl')
       # +cmpxchg16b
       # macOS is skipped because it is +cmpxchg16b by default
       - run: tools/test.sh -vv $TARGET $DOCTEST_XCOMPILE $BUILD_STD

src/imp/atomic128/README.md

@@ -26,11 +26,12 @@ Here is the table of targets that support run-time feature detection and the ins
 | target_arch | target_os/target_env | instruction/API |
 | ----------- | -------------------- | --------------- |
 | x86_64      | all (except for sgx) | cpuid           |
-| aarch64     | linux-gnu/android    | getauxval       |
-| aarch64     | other linux          | dlsym(getauxval) (via is_aarch64_feature_detected) |
+| aarch64     | linux/android        | getauxval       |
 | aarch64     | freebsd              | elf_aux_info    |
 | aarch64     | macos/openbsd        | sysctl          |
 | aarch64     | windows              | IsProcessorFeaturePresent |
 | aarch64     | fuchsia              | zx_system_get_features |
 
 For targets not included in the above table, run-time detections are disabled and work the same as when `--cfg portable_atomic_no_outline_atomics` is set.
+
+See [detect/aarch64_auxv.rs](detect/aarch64_auxv.rs) module-level comments for more details on Linux/Android/FreeBSD.

src/imp/atomic128/aarch64.rs

@@ -52,9 +52,17 @@
 
 include!("macros.rs");
 
+// On musl with static linking, it seems that getauxval is not always available.
+// See detect/aarch64_auxv.rs for more.
 #[cfg(not(portable_atomic_no_outline_atomics))]
 #[cfg(any(
-    all(target_os = "linux", target_env = "gnu"),
+    all(
+        target_os = "linux",
+        any(
+            target_env = "gnu",
+            all(any(target_env = "musl", target_env = "ohos"), not(target_feature = "crt-static")),
+        ),
+    ),
     target_os = "android",
     target_os = "freebsd",
 ))]
@@ -72,10 +80,6 @@ mod detect;
 #[cfg(target_os = "windows")]
 #[path = "detect/aarch64_windows.rs"]
 mod detect;
-#[cfg(not(portable_atomic_no_outline_atomics))]
-#[cfg(all(target_os = "linux", not(target_env = "gnu")))]
-#[path = "detect/aarch64_std.rs"]
-mod detect;
 
 // test only
 #[cfg(test)]
@@ -310,7 +314,16 @@ unsafe fn atomic_compare_exchange(
         not(portable_atomic_no_aarch64_target_feature),
         not(portable_atomic_no_outline_atomics),
         any(
-            target_os = "linux",
+            all(
+                target_os = "linux",
+                any(
+                    target_env = "gnu",
+                    all(
+                        any(target_env = "musl", target_env = "ohos"),
+                        not(target_feature = "crt-static"),
+                    ),
+                ),
+            ),
             target_os = "android",
             target_os = "freebsd",
             target_os = "openbsd",
@@ -325,7 +338,16 @@ unsafe fn atomic_compare_exchange(
         not(portable_atomic_no_aarch64_target_feature),
         not(portable_atomic_no_outline_atomics),
         any(
-            target_os = "linux",
+            all(
+                target_os = "linux",
+                any(
+                    target_env = "gnu",
+                    all(
+                        any(target_env = "musl", target_env = "ohos"),
+                        not(target_feature = "crt-static"),
+                    ),
+                ),
+            ),
             target_os = "android",
             target_os = "freebsd",
             target_os = "openbsd",

src/imp/atomic128/detect/aarch64_auxv.rs

@@ -8,20 +8,23 @@
 //
 // - On glibc (*-linux-gnu*), [aarch64 support is available on glibc 2.17+](https://sourceware.org/legacy-ml/libc-announce/2012/msg00001.html)
 //   and is newer than [glibc 2.16 that added getauxval](https://sourceware.org/legacy-ml/libc-announce/2012/msg00000.html).
+// - On musl (*-linux-musl*, *-linux-ohos*), [aarch64 support is available on musl 1.1.7+](https://git.musl-libc.org/cgit/musl/tree/WHATSNEW?h=v1.1.7#n1422)
+//   and is newer than [musl 1.1.0 that added getauxval](https://git.musl-libc.org/cgit/musl/tree/WHATSNEW?h=v1.1.0#n1197).
+//   https://github.com/rust-lang/rust/commit/9a04ae4997493e9260352064163285cddc43de3c
 // - On bionic (*-android*), [64-bit architecture support is available on Android 5.0+ (API level 21+)](https://android-developers.googleblog.com/2014/10/whats-new-in-android-50-lollipop.html)
 //   and is newer than [Android 4.3 (API level 18) that added getauxval](https://github.com/aosp-mirror/platform_bionic/blob/d3ebc2f7c49a9893b114124d4a6b315f3a328764/libc/include/sys/auxv.h#L49).
 //
-// On other Linux targets, we cannot assume that getauxval is always available,
-// so we use is_aarch64_feature_detected which uses dlsym (+io fallback) instead
-// of this module.
+// However, on musl with static linking, it seems that getauxval is not always available, independent of version requirements: https://github.com/rust-lang/rust/issues/89626
+// (That problem may have been fixed in https://github.com/rust-lang/rust/commit/9a04ae4997493e9260352064163285cddc43de3c,
+// but even in the version containing that patch, [there is report](https://github.com/rust-lang/rust/issues/89626#issuecomment-1242636038)
+// of the same error.)
 //
-// - On musl (*-linux-musl*), [aarch64 support is available on musl 1.1.7+](https://git.musl-libc.org/cgit/musl/tree/WHATSNEW?h=v1.1.7#n1422)
-//   and is newer than [musl 1.1.0 that added getauxval](https://git.musl-libc.org/cgit/musl/tree/WHATSNEW?h=v1.1.0#n1197).
-//   However, it seems that getauxval is not always available, independent of version requirements: https://github.com/rust-lang/rust/issues/89626
-//   (That problem may have been fixed in https://github.com/rust-lang/rust/commit/9a04ae4997493e9260352064163285cddc43de3c,
-//   but even in the version containing that patch, [there is report](https://github.com/rust-lang/rust/issues/89626#issuecomment-1242636038)
-//   of the same error.)
-// - On uClibc-ng (*-linux-uclibc*), they [recently added getauxval](https://repo.or.cz/uclibc-ng.git/commitdiff/d869bb1600942c01a77539128f9ba5b5b55ad647)
+// On other Linux targets, we cannot assume that getauxval is always available, so we don't support
+// outline-atomics for now.
+//
+// - On musl with static linking. See the above for more.
+//   Also, in this case, dlsym(getauxval) always returns null.
+// - On uClibc-ng (*-linux-uclibc*, *-l4re-uclibc*), they [recently added getauxval](https://repo.or.cz/uclibc-ng.git/commitdiff/d869bb1600942c01a77539128f9ba5b5b55ad647)
 //   but have not released it yet (as of 2023-02-09).
 // - On Picolibc, [Picolibc 1.4.6 added getauxval stub](https://github.com/picolibc/picolibc#picolibc-version-146).
 //