diff options
Diffstat (limited to 'library/stdarch/crates/std_detect/src')
| -rw-r--r-- | library/stdarch/crates/std_detect/src/detect/os/linux/auxvec.rs | 129 |
1 files changed, 35 insertions, 94 deletions
diff --git a/library/stdarch/crates/std_detect/src/detect/os/linux/auxvec.rs b/library/stdarch/crates/std_detect/src/detect/os/linux/auxvec.rs index e4ffffd7b21..8c911fd8d96 100644 --- a/library/stdarch/crates/std_detect/src/detect/os/linux/auxvec.rs +++ b/library/stdarch/crates/std_detect/src/detect/os/linux/auxvec.rs @@ -74,68 +74,8 @@ pub(crate) struct AuxVec { /// [auxvec_h]: https://github.com/torvalds/linux/blob/master/include/uapi/linux/auxvec.h /// [auxv_docs]: https://docs.rs/auxv/0.3.3/auxv/ pub(crate) fn auxv() -> Result<AuxVec, ()> { - #[cfg(all( - feature = "std_detect_dlsym_getauxval", - not(all( - target_os = "linux", - any(target_env = "gnu", target_env = "musl", target_env = "ohos"), - )), - // TODO: libc crate currently doesn't provide getauxval on 32-bit Android. - not(all(target_os = "android", target_pointer_width = "64")), - ))] - { - // Try to call a dynamically-linked getauxval function. - if let Ok(hwcap) = getauxval(AT_HWCAP) { - // Targets with only AT_HWCAP: - #[cfg(any( - target_arch = "riscv32", - target_arch = "riscv64", - target_arch = "mips", - target_arch = "mips64" - ))] - { - // Zero could indicate that no features were detected, but it's also used to - // indicate an error. In either case, try the fallback. - if hwcap != 0 { - return Ok(AuxVec { hwcap }); - } - } - - // Targets with AT_HWCAP and AT_HWCAP2: - #[cfg(any( - target_arch = "aarch64", - target_arch = "arm", - target_arch = "powerpc", - target_arch = "powerpc64", - target_arch = "s390x", - ))] - { - if let Ok(hwcap2) = getauxval(AT_HWCAP2) { - // Zero could indicate that no features were detected, but it's also used to - // indicate an error. In particular, on many platforms AT_HWCAP2 will be - // legitimately zero, since it contains the most recent feature flags. Use the - // fallback only if no features were detected at all. - if hwcap != 0 || hwcap2 != 0 { - return Ok(AuxVec { hwcap, hwcap2 }); - } - } - } - - // Intentionnaly not used - let _ = hwcap; - } - } - - #[cfg(not(all( - feature = "std_detect_dlsym_getauxval", - not(all( - target_os = "linux", - any(target_env = "gnu", target_env = "musl", target_env = "ohos"), - )), - // TODO: libc crate currently doesn't provide getauxval on 32-bit Android. - not(all(target_os = "android", target_pointer_width = "64")), - )))] - { + // Try to call a getauxval function. + if let Ok(hwcap) = getauxval(AT_HWCAP) { // Targets with only AT_HWCAP: #[cfg(any( target_arch = "riscv32", @@ -145,7 +85,6 @@ pub(crate) fn auxv() -> Result<AuxVec, ()> { target_arch = "loongarch64", ))] { - let hwcap = unsafe { libc::getauxval(AT_HWCAP as libc::c_ulong) as usize }; // Zero could indicate that no features were detected, but it's also used to indicate // an error. In either case, try the fallback. if hwcap != 0 { @@ -162,16 +101,19 @@ pub(crate) fn auxv() -> Result<AuxVec, ()> { target_arch = "s390x", ))] { - let hwcap = unsafe { libc::getauxval(AT_HWCAP as libc::c_ulong) as usize }; - let hwcap2 = unsafe { libc::getauxval(AT_HWCAP2 as libc::c_ulong) as usize }; - // Zero could indicate that no features were detected, but it's also used to indicate - // an error. In particular, on many platforms AT_HWCAP2 will be legitimately zero, - // since it contains the most recent feature flags. Use the fallback only if no - // features were detected at all. - if hwcap != 0 || hwcap2 != 0 { - return Ok(AuxVec { hwcap, hwcap2 }); + if let Ok(hwcap2) = getauxval(AT_HWCAP2) { + // Zero could indicate that no features were detected, but it's also used to indicate + // an error. In particular, on many platforms AT_HWCAP2 will be legitimately zero, + // since it contains the most recent feature flags. Use the fallback only if no + // features were detected at all. + if hwcap != 0 || hwcap2 != 0 { + return Ok(AuxVec { hwcap, hwcap2 }); + } } } + + // Intentionnaly not used + let _ = hwcap; } #[cfg(feature = "std_detect_file_io")] @@ -187,32 +129,31 @@ pub(crate) fn auxv() -> Result<AuxVec, ()> { } /// Tries to read the `key` from the auxiliary vector by calling the -/// dynamically-linked `getauxval` function. If the function is not linked, -/// this function return `Err`. -#[cfg(any( - test, - all( - feature = "std_detect_dlsym_getauxval", - not(all( - target_os = "linux", - any(target_env = "gnu", target_env = "musl", target_env = "ohos"), - )), - // TODO: libc crate currently doesn't provide getauxval on 32-bit Android. - not(all(target_os = "android", target_pointer_width = "64")), - ) -))] +/// `getauxval` function. If the function is not linked, this function return `Err`. fn getauxval(key: usize) -> Result<usize, ()> { - use libc; - pub type F = unsafe extern "C" fn(usize) -> usize; - unsafe { - let ptr = libc::dlsym(libc::RTLD_DEFAULT, c"getauxval".as_ptr()); - if ptr.is_null() { - return Err(()); + type F = unsafe extern "C" fn(libc::c_ulong) -> libc::c_ulong; + cfg_if::cfg_if! { + if #[cfg(all( + feature = "std_detect_dlsym_getauxval", + not(all( + target_os = "linux", + any(target_env = "gnu", target_env = "musl", target_env = "ohos"), + )), + // TODO: libc crate currently doesn't provide getauxval on 32-bit Android. + not(all(target_os = "android", target_pointer_width = "64")), + ))] { + let ffi_getauxval: F = unsafe { + let ptr = libc::dlsym(libc::RTLD_DEFAULT, c"getauxval".as_ptr()); + if ptr.is_null() { + return Err(()); + } + core::mem::transmute(ptr) + }; + } else { + let ffi_getauxval: F = libc::getauxval; } - - let ffi_getauxval: F = core::mem::transmute(ptr); - Ok(ffi_getauxval(key)) } + Ok(unsafe { ffi_getauxval(key as libc::c_ulong) as usize }) } /// Tries to read the auxiliary vector from the `file`. If this fails, this |