// SPDX-License-Identifier: Apache-2.0 OR MIT // The rustc-cfg emitted by the build script are *not* public API. #![allow(clippy::match_same_arms)] // https://github.com/rust-lang/rust-clippy/issues/12044 #[path = "version.rs"] mod version; use self::version::{rustc_version, Version}; use std::{env, str}; include!("no_atomic.rs"); fn main() { println!("cargo:rerun-if-changed=build.rs"); println!("cargo:rerun-if-changed=no_atomic.rs"); println!("cargo:rerun-if-changed=version.rs"); #[cfg(feature = "unsafe-assume-single-core")] println!("cargo:rustc-cfg=portable_atomic_unsafe_assume_single_core"); #[cfg(feature = "s-mode")] println!("cargo:rustc-cfg=portable_atomic_s_mode"); #[cfg(feature = "force-amo")] println!("cargo:rustc-cfg=portable_atomic_force_amo"); #[cfg(feature = "disable-fiq")] println!("cargo:rustc-cfg=portable_atomic_disable_fiq"); let target = &*env::var("TARGET").expect("TARGET not set"); let target_arch = &*env::var("CARGO_CFG_TARGET_ARCH").expect("CARGO_CFG_TARGET_ARCH not set"); let target_os = &*env::var("CARGO_CFG_TARGET_OS").expect("CARGO_CFG_TARGET_OS not set"); let version = match rustc_version() { Some(version) => version, None => { if env::var_os("PORTABLE_ATOMIC_DENY_WARNINGS").is_some() { panic!("unable to determine rustc version") } println!( "cargo:warning={}: unable to determine rustc version; assuming latest stable rustc (1.{})", env!("CARGO_PKG_NAME"), Version::LATEST.minor ); Version::LATEST } }; if version.minor >= 80 { println!( r#"cargo:rustc-check-cfg=cfg(target_feature,values("experimental-zacas","fast-serialization","load-store-on-cond","distinct-ops","miscellaneous-extensions-3"))"# ); // Custom cfgs set by build script. Not public API. // grep -F 'cargo:rustc-cfg=' build.rs | grep -Ev '^ *//' | sed -E 's/^.*cargo:rustc-cfg=//; s/(=\\)?".*$//' | LC_ALL=C sort -u | tr '\n' ',' | sed -E 's/,$/\n/' println!( "cargo:rustc-check-cfg=cfg(portable_atomic_disable_fiq,portable_atomic_force_amo,portable_atomic_ll_sc_rmw,portable_atomic_new_atomic_intrinsics,portable_atomic_no_asm,portable_atomic_no_asm_maybe_uninit,portable_atomic_no_atomic_64,portable_atomic_no_atomic_cas,portable_atomic_no_atomic_load_store,portable_atomic_no_atomic_min_max,portable_atomic_no_cfg_target_has_atomic,portable_atomic_no_cmpxchg16b_intrinsic,portable_atomic_no_cmpxchg16b_target_feature,portable_atomic_no_const_mut_refs,portable_atomic_no_const_raw_ptr_deref,portable_atomic_no_const_transmute,portable_atomic_no_core_unwind_safe,portable_atomic_no_diagnostic_namespace,portable_atomic_no_offset_of,portable_atomic_no_stronger_failure_ordering,portable_atomic_no_track_caller,portable_atomic_no_unsafe_op_in_unsafe_fn,portable_atomic_pre_llvm_15,portable_atomic_pre_llvm_16,portable_atomic_pre_llvm_18,portable_atomic_s_mode,portable_atomic_sanitize_thread,portable_atomic_target_feature,portable_atomic_unsafe_assume_single_core,portable_atomic_unstable_asm,portable_atomic_unstable_asm_experimental_arch,portable_atomic_unstable_cfg_target_has_atomic,portable_atomic_unstable_isa_attribute)" ); // TODO: handle multi-line target_feature_fallback // grep -F 'target_feature_fallback("' build.rs | grep -Ev '^ *//' | sed -E 's/^.*target_feature_fallback\(//; s/",.*$/"/' | LC_ALL=C sort -u | tr '\n' ',' | sed -E 's/,$/\n/' println!( r#"cargo:rustc-check-cfg=cfg(portable_atomic_target_feature,values("cmpxchg16b","distinct-ops","experimental-zacas","fast-serialization","load-store-on-cond","lse","lse128","lse2","mclass","miscellaneous-extensions-3","quadword-atomics","rcpc3","v6","zaamo","zabha"))"# ); } // https://github.com/rust-lang/rust/pull/123745 (includes https://github.com/rust-lang/cargo/pull/13560) merged in Rust 1.79 (nightly-2024-04-11). if !version.probe(79, 2024, 4, 10) { // HACK: If --target is specified, rustflags is not applied to the build // script itself, so the build script will not be recompiled when rustflags // is changed. That in itself is not a problem, but the old Cargo does // not rerun the build script as well, which can be problematic. // https://github.com/rust-lang/cargo/issues/13003 // This problem has been fixed in 1.79 so only older versions need a workaround. println!("cargo:rerun-if-env-changed=CARGO_ENCODED_RUSTFLAGS"); println!("cargo:rerun-if-env-changed=RUSTFLAGS"); println!("cargo:rerun-if-env-changed=CARGO_BUILD_RUSTFLAGS"); let mut target_upper = target.replace(|c: char| c == '-' || c == '.', "_"); target_upper.make_ascii_uppercase(); println!("cargo:rerun-if-env-changed=CARGO_TARGET_{}_RUSTFLAGS", target_upper); } // Note that cfgs are `no_`*, not `has_*`. This allows treating as the latest // stable rustc is used when the build script doesn't run. This is useful // for non-cargo build systems that don't run the build script. // atomic_min_max stabilized in Rust 1.45 (nightly-2020-05-30): https://github.com/rust-lang/rust/pull/72324 if !version.probe(45, 2020, 5, 29) { println!("cargo:rustc-cfg=portable_atomic_no_atomic_min_max"); } // track_caller stabilized in Rust 1.46 (nightly-2020-07-02): https://github.com/rust-lang/rust/pull/72445 if !version.probe(46, 2020, 7, 1) { println!("cargo:rustc-cfg=portable_atomic_no_track_caller"); } // unsafe_op_in_unsafe_fn stabilized in Rust 1.52 (nightly-2021-03-11): https://github.com/rust-lang/rust/pull/79208 if !version.probe(52, 2021, 3, 10) { println!("cargo:rustc-cfg=portable_atomic_no_unsafe_op_in_unsafe_fn"); } // const_transmute stabilized in Rust 1.56 (nightly-2021-07-29): https://github.com/rust-lang/rust/pull/85769 if !version.probe(56, 2021, 7, 28) { println!("cargo:rustc-cfg=portable_atomic_no_const_transmute"); } // https://github.com/rust-lang/rust/pull/84662 merged in Rust 1.56 (nightly-2021-08-02). if !version.probe(56, 2021, 8, 1) { println!("cargo:rustc-cfg=portable_atomic_no_core_unwind_safe"); } // const_raw_ptr_deref stabilized in Rust 1.58 (nightly-2021-11-15): https://github.com/rust-lang/rust/pull/89551 if !version.probe(58, 2021, 11, 14) { println!("cargo:rustc-cfg=portable_atomic_no_const_raw_ptr_deref"); } // https://github.com/rust-lang/rust/pull/98383 merged in Rust 1.64 (nightly-2022-07-19). if !version.probe(64, 2022, 7, 18) { println!("cargo:rustc-cfg=portable_atomic_no_stronger_failure_ordering"); } // https://github.com/rust-lang/rust/pull/114790 merged in nightly-2023-08-24 if !version.probe(74, 2023, 8, 23) { println!("cargo:rustc-cfg=portable_atomic_no_asm_maybe_uninit"); } // For test if version.minor < 77 { println!("cargo:rustc-cfg=portable_atomic_no_offset_of"); } // #[diagnostic] stabilized in Rust 1.78 (nightly-2024-03-09): https://github.com/rust-lang/rust/pull/119888 if !version.probe(78, 2024, 3, 8) { println!("cargo:rustc-cfg=portable_atomic_no_diagnostic_namespace"); } // const_mut_refs/const_refs_to_cell stabilized in Rust 1.83 (nightly-2024-09-16): https://github.com/rust-lang/rust/pull/129195 if !version.probe(83, 2024, 9, 15) { println!("cargo:rustc-cfg=portable_atomic_no_const_mut_refs"); } // asm! on AArch64, Arm, RISC-V, x86, and x86_64 stabilized in Rust 1.59 (nightly-2021-12-16): https://github.com/rust-lang/rust/pull/91728 let no_asm = !version.probe(59, 2021, 12, 15); if no_asm { if version.nightly && version.probe(46, 2020, 6, 20) && ((target_arch != "x86" && target_arch != "x86_64") || version.llvm >= 10) && is_allowed_feature("asm") { // This feature was added in Rust 1.45 (nightly-2020-05-20), but // concat! in asm! requires Rust 1.46 (nightly-2020-06-21). // x86 intel syntax requires LLVM 10 (since Rust 1.53, the minimum // external LLVM version is 10+: https://github.com/rust-lang/rust/pull/83387). // The part of this feature we use has not been changed since nightly-2020-06-21 // until it was stabilized in nightly-2021-12-16, so it can be safely enabled in // nightly, which is older than nightly-2021-12-16. println!("cargo:rustc-cfg=portable_atomic_unstable_asm"); } println!("cargo:rustc-cfg=portable_atomic_no_asm"); } else { match target_arch { "arm64ec" | "s390x" => { // asm! on Arm64EC and s390x stabilized in Rust 1.84 (nightly-2024-11-11): https://github.com/rust-lang/rust/pull/131781, https://github.com/rust-lang/rust/pull/131258 if !version.probe(84, 2024, 11, 10) { if version.nightly && (target_arch != "s390x" || version.probe(71, 2023, 5, 8)) && is_allowed_feature("asm_experimental_arch") { // https://github.com/rust-lang/rust/pull/111331 merged in Rust 1.71 (nightly-2023-05-09). // The part of this feature we use has not been changed since nightly-2023-05-09 // until it was stabilized in nightly-2024-11-11, so it can be safely enabled in // nightly, which is older than nightly-2024-11-11. println!("cargo:rustc-cfg=portable_atomic_unstable_asm_experimental_arch"); } else { println!("cargo:rustc-cfg=portable_atomic_no_asm"); } } } _ => {} } } // feature(cfg_target_has_atomic) stabilized in Rust 1.60 (nightly-2022-02-11): https://github.com/rust-lang/rust/pull/93824 if !version.probe(60, 2022, 2, 10) { if version.nightly && version.probe(40, 2019, 10, 13) && is_allowed_feature("cfg_target_has_atomic") { // This feature has not been changed since the change in Rust 1.40 (nightly-2019-10-14) // until it was stabilized in nightly-2022-02-11, so it can be safely enabled in // nightly, which is older than nightly-2022-02-11. println!("cargo:rustc-cfg=portable_atomic_unstable_cfg_target_has_atomic"); } else { println!("cargo:rustc-cfg=portable_atomic_no_cfg_target_has_atomic"); let target = &*convert_custom_linux_target(target); if NO_ATOMIC_CAS.contains(&target) { println!("cargo:rustc-cfg=portable_atomic_no_atomic_cas"); } if NO_ATOMIC_64.contains(&target) { println!("cargo:rustc-cfg=portable_atomic_no_atomic_64"); } else { // Otherwise, assuming `"max-atomic-width" == 64` or `"max-atomic-width" == 128`. } } } // We don't need to use convert_custom_linux_target here because all linux targets have atomics. if NO_ATOMIC.contains(&target) { println!("cargo:rustc-cfg=portable_atomic_no_atomic_load_store"); } if version.llvm < 18 { println!("cargo:rustc-cfg=portable_atomic_pre_llvm_18"); if version.llvm < 16 { println!("cargo:rustc-cfg=portable_atomic_pre_llvm_16"); if version.llvm < 15 { println!("cargo:rustc-cfg=portable_atomic_pre_llvm_15"); } } } if version.nightly { // `cfg(sanitize = "..")` is not stabilized. let sanitize = env::var("CARGO_CFG_SANITIZE").unwrap_or_default(); if sanitize.contains("thread") { // Most kinds of sanitizers are not compatible with asm // (https://github.com/google/sanitizers/issues/192), // but it seems that ThreadSanitizer is the only one that can cause // false positives in our code. println!("cargo:rustc-cfg=portable_atomic_sanitize_thread"); } // https://github.com/rust-lang/rust/pull/93868 merged in Rust 1.60 (nightly-2022-02-13). if !no_asm && (target_arch == "powerpc64" && version.probe(60, 2022, 2, 12)) && is_allowed_feature("asm_experimental_arch") { println!("cargo:rustc-cfg=portable_atomic_unstable_asm_experimental_arch"); } } match target_arch { "x86_64" => { // cmpxchg16b_target_feature stabilized in Rust 1.69 (nightly-2023-03-01): https://github.com/rust-lang/rust/pull/106774 if !version.probe(69, 2023, 2, 28) { println!("cargo:rustc-cfg=portable_atomic_no_cmpxchg16b_target_feature"); } // For Miri and ThreadSanitizer. // https://github.com/rust-lang/rust/pull/109359 (includes https://github.com/rust-lang/stdarch/pull/1358) merged in Rust 1.70 (nightly-2023-03-24). if version.nightly && !version.probe(70, 2023, 3, 23) { println!("cargo:rustc-cfg=portable_atomic_no_cmpxchg16b_intrinsic"); } // cmpxchg16b_target_feature stabilized in Rust 1.69. if needs_target_feature_fallback(&version, Some(69)) { // x86_64 Apple targets always support CMPXCHG16B: // https://github.com/rust-lang/rust/blob/1.68.0/compiler/rustc_target/src/spec/x86_64_apple_darwin.rs#L8 // https://github.com/rust-lang/rust/blob/1.68.0/compiler/rustc_target/src/spec/apple_base.rs#L69-L70 // (Since Rust 1.78, Windows (except Windows 7) targets also enable CMPXCHG16B, but // this branch is only used on pre-1.69 that cmpxchg16b_target_feature is unstable.) // Script to get builtin targets that support CMPXCHG16B by default: // $ (for target in $(rustc --print target-list | grep -E '^x86_64'); do rustc --print cfg --target "${target}" | grep -Fq '"cmpxchg16b"' && printf '%s\n' "${target}"; done) let is_apple = env::var("CARGO_CFG_TARGET_VENDOR").unwrap_or_default() == "apple"; let has_cmpxchg16b = is_apple; // LLVM recognizes this also as cx16 target feature: https://godbolt.org/z/KM3jz616j // However, it is unlikely that rustc will support that name, so we ignore it. target_feature_fallback("cmpxchg16b", has_cmpxchg16b); } } "aarch64" | "arm64ec" => { // For Miri and ThreadSanitizer. // https://github.com/rust-lang/rust/pull/97423 merged in Rust 1.64 (nightly-2022-06-30). if version.nightly && version.probe(64, 2022, 6, 29) { println!("cargo:rustc-cfg=portable_atomic_new_atomic_intrinsics"); } // target_feature "lse2"/"lse128"/"rcpc3" is unstable and available on rustc side since nightly-2024-08-30: https://github.com/rust-lang/rust/pull/128192 if !version.probe(82, 2024, 8, 29) || needs_target_feature_fallback(&version, None) { // FEAT_LSE2 doesn't imply FEAT_LSE. FEAT_LSE128 implies FEAT_LSE but not FEAT_LSE2. // AArch64 macOS always supports FEAT_LSE and FEAT_LSE2 because M1 is Armv8.4 with all features of Armv8.5 except FEAT_BTI: // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/AArch64/AArch64Processors.td#L1203 // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/AArch64/AArch64Processors.td#L865 // Script to get builtin targets that support FEAT_LSE/FEAT_LSE2 by default: // $ (for target in $(rustc --print target-list | grep -E '^aarch64|^arm64'); do rustc --print cfg --target "${target}" | grep -Fq '"lse"' && printf '%s\n' "${target}"; done) // $ (for target in $(rustc --print target-list | grep -E '^aarch64|^arm64'); do rustc --print cfg --target "${target}" | grep -Fq '"lse2"' && printf '%s\n' "${target}"; done) let is_macos = target_os == "macos"; let mut has_lse = is_macos; target_feature_fallback("lse2", is_macos); has_lse |= target_feature_fallback("lse128", false); target_feature_fallback("rcpc3", false); // aarch64_target_feature stabilized in Rust 1.61. if needs_target_feature_fallback(&version, Some(61)) { target_feature_fallback("lse", has_lse); } } // As of Apple M1/M1 Pro, on Apple hardware, CAS-loop-based RMW is much slower than // LL/SC-loop-based RMW: https://github.com/taiki-e/portable-atomic/pull/89 let is_apple = env::var("CARGO_CFG_TARGET_VENDOR").unwrap_or_default() == "apple"; if is_apple || target_cpu().map_or(false, |cpu| cpu.starts_with("apple-")) { println!("cargo:rustc-cfg=portable_atomic_ll_sc_rmw"); } } "arm" => { // For non-Linux/Android pre-v6 Arm (tier 3) with unsafe_assume_single_core enabled. // feature(isa_attribute) stabilized in Rust 1.67 (nightly-2022-11-06): https://github.com/rust-lang/rust/pull/102458 if version.nightly && !version.probe(67, 2022, 11, 5) { println!("cargo:rustc-cfg=portable_atomic_unstable_isa_attribute"); } if needs_target_feature_fallback(&version, None) { // #[cfg(target_feature = "v7")] and others don't work on stable. // armv7-unknown-linux-gnueabihf // ^^ let mut subarch = strip_prefix(target, "arm").or_else(|| strip_prefix(target, "thumb")).unwrap(); subarch = strip_prefix(subarch, "eb").unwrap_or(subarch); // ignore endianness subarch = subarch.split('-').next().unwrap(); // ignore vender/os/env subarch = subarch.split('.').next().unwrap(); // ignore .base/.main suffix let mut known = true; // See https://github.com/taiki-e/atomic-maybe-uninit/blob/HEAD/build.rs for details let mut mclass = false; match subarch { "v7" | "v7a" | "v7neon" | "v7s" | "v7k" | "v8" | "v8a" | "v9" | "v9a" => {} // aclass "v7r" | "v8r" | "v9r" => {} // rclass "v6m" | "v7em" | "v7m" | "v8m" => mclass = true, // arm-linux-androideabi is v5te // https://github.com/rust-lang/rust/blob/1.80.0/compiler/rustc_target/src/spec/targets/arm_linux_androideabi.rs#L18 _ if target == "arm-linux-androideabi" => subarch = "v5te", // armeb-unknown-linux-gnueabi is v8 & aclass // https://github.com/rust-lang/rust/blob/1.80.0/compiler/rustc_target/src/spec/targets/armeb_unknown_linux_gnueabi.rs#L18 _ if target == "armeb-unknown-linux-gnueabi" => subarch = "v8", // Legacy Arm architectures (pre-v7 except v6m) don't have *class target feature. "" => subarch = "v6", "v4t" | "v5te" | "v6" | "v6k" => {} _ => { known = false; if env::var_os("PORTABLE_ATOMIC_DENY_WARNINGS").is_some() { panic!("unrecognized Arm subarch: {}", target) } println!( "cargo:warning={}: unrecognized Arm subarch: {}", env!("CARGO_PKG_NAME"), target ); } } let v6 = known && (subarch.starts_with("v6") || subarch.starts_with("v7") || subarch.starts_with("v8") || subarch.starts_with("v9")); target_feature_fallback("v6", v6); target_feature_fallback("mclass", mclass); } } "riscv32" | "riscv64" => { // zabha and zacas imply zaamo in GCC and Rust, but do not in LLVM (but enabling them // without zaamo or a is not allowed, so we can assume zaamo is available when zabha is enabled). // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/TargetParser/RISCVISAInfo.cpp#L772-L778 // https://github.com/gcc-mirror/gcc/blob/08693e29ec186fd7941d0b73d4d466388971fe2f/gcc/config/riscv/arch-canonicalize#L45-L46 // https://github.com/rust-lang/rust/pull/130877 let mut has_zaamo = false; // As of rustc 1.80, target_feature "zacas" is not available on rustc side: // https://github.com/rust-lang/rust/blob/1.80.0/compiler/rustc_target/src/target_features.rs#L273 if version.llvm == 19 { // amocas.{w,d,q} (and amocas.{b,h} if zabha is also available) // available as experimental since LLVM 17 https://github.com/llvm/llvm-project/commit/29f630a1ddcbb03caa31b5002f0cbc105ff3a869 // attempted to make non-experimental in LLVM 19 https://github.com/llvm/llvm-project/commit/95aab69c109adf29e183090c25dc95c773215746 // but reverted in https://github.com/llvm/llvm-project/commit/70e7d26e560173c8b9db4c75ab4a3004cd5f021a // check == 19 instead of range 17..=19 because it is more experimental in LLVM 17/18. // check == 19 instead of >= 19 because "experimental-zacas" feature // may no longer exist when it is marked as non-experimental in LLVM 20. // https://github.com/llvm/llvm-project/commit/614aeda93b2225c6eb42b00ba189ba7ca2585c60 has_zaamo |= target_feature_fallback("experimental-zacas", false); } // target_feature "zaamo"/"zabha" is unstable and available on rustc side since nightly-2024-10-02: https://github.com/rust-lang/rust/pull/130877 if !version.probe(83, 2024, 10, 1) || needs_target_feature_fallback(&version, None) { if version.llvm >= 19 { // amo*.{b,h} // available since LLVM 19 https://github.com/llvm/llvm-project/commit/89f87c387627150d342722b79c78cea2311cddf7 / https://github.com/llvm/llvm-project/commit/6b7444964a8d028989beee554a1f5c61d16a1cac has_zaamo |= target_feature_fallback("zabha", false); } // amo*.{w,d} target_feature_fallback("zaamo", has_zaamo); } } "powerpc64" => { // target_feature "quadword-atomics" is unstable and available on rustc side since nightly-2024-09-28: https://github.com/rust-lang/rust/pull/130873 if !version.probe(83, 2024, 9, 27) || needs_target_feature_fallback(&version, None) { let target_endian = env::var("CARGO_CFG_TARGET_ENDIAN").expect("CARGO_CFG_TARGET_ENDIAN not set"); // powerpc64le is pwr8 by default https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/PowerPC/PPC.td#L702 // See also https://github.com/rust-lang/rust/issues/59932 let mut pwr8_features = target_endian == "little"; if let Some(cpu) = &target_cpu() { if let Some(mut cpu_version) = strip_prefix(cpu, "pwr") { cpu_version = strip_suffix(cpu_version, "x").unwrap_or(cpu_version); // for pwr5x and pwr6x if let Ok(cpu_version) = cpu_version.parse::() { pwr8_features = cpu_version >= 8; } } else { // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/PowerPC/PPC.td#L702 // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/PowerPC/PPC.td#L483 // On the minimum external LLVM version of the oldest rustc version which we can use asm_experimental_arch // on this target (see CI config for more), "future" is based on pwr10 features. // https://github.com/llvm/llvm-project/blob/llvmorg-12.0.0/llvm/lib/Target/PowerPC/PPC.td#L370 pwr8_features = cpu == "future" || cpu == "ppc64le"; } } // power8 features: https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/PowerPC/PPC.td#L409 // lqarx and stqcx. target_feature_fallback("quadword-atomics", pwr8_features); } } "s390x" => { // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZFeatures.td let mut arch9_features = false; // z196+ let mut arch13_features = false; // z15+ if let Some(cpu) = target_cpu() { // LLVM and GCC recognize the same names: // https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZProcessors.td // https://github.com/gcc-mirror/gcc/blob/releases/gcc-14.2.0/gcc/config/s390/s390.opt#L58-L125 match &*cpu { "arch9" | "z196" | "arch10" | "zEC12" | "arch11" | "z13" | "arch12" | "z14" => { arch9_features = true; } "arch13" | "z15" | "arch14" | "z16" => { arch9_features = true; arch13_features = true; } _ => {} } } // As of rustc 1.80, target_feature "fast-serialization"/"load-store-on-cond"/"distinct-ops"/"miscellaneous-extensions-3" is not available on rustc side: // https://github.com/rust-lang/rust/blob/1.80.0/compiler/rustc_target/src/target_features.rs // arch9 features: https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZFeatures.td#L103 // bcr 14,0 target_feature_fallback("fast-serialization", arch9_features); // {l,st}oc{,g}{,r} target_feature_fallback("load-store-on-cond", arch9_features); // {al,sl,n,o,x}{,g}rk target_feature_fallback("distinct-ops", arch9_features); // arch13 features: https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZFeatures.td#L301 // nand (nnr{,g}k), select (sel{,g}r), etc. target_feature_fallback("miscellaneous-extensions-3", arch13_features); } _ => {} } } // HACK: Currently, it seems that the only way to handle unstable target // features on the stable is to parse the `-C target-feature` in RUSTFLAGS. // // - #[cfg(target_feature = "unstable_target_feature")] doesn't work on stable. // - CARGO_CFG_TARGET_FEATURE excludes unstable target features on stable. // // As mentioned in the [RFC2045], unstable target features are also passed to LLVM // (e.g., https://godbolt.org/z/4rr7rMcfG), so this hack works properly on stable. // // [RFC2045]: https://rust-lang.github.io/rfcs/2045-target-feature.html#backend-compilation-options fn needs_target_feature_fallback(version: &Version, stable: Option) -> bool { match stable { // In these cases, cfg(target_feature = "...") would work, so skip emitting our own fallback target_feature cfg. _ if version.nightly => false, Some(stabilized) if version.minor >= stabilized => false, _ => true, } } fn target_feature_fallback(name: &str, mut has_target_feature: bool) -> bool { if let Some(rustflags) = env::var_os("CARGO_ENCODED_RUSTFLAGS") { for mut flag in rustflags.to_string_lossy().split('\x1f') { flag = strip_prefix(flag, "-C").unwrap_or(flag); if let Some(flag) = strip_prefix(flag, "target-feature=") { for s in flag.split(',') { // TODO: Handles cases where a specific target feature // implicitly enables another target feature. match (s.as_bytes().first(), s.as_bytes().get(1..)) { (Some(b'+'), Some(f)) if f == name.as_bytes() => has_target_feature = true, (Some(b'-'), Some(f)) if f == name.as_bytes() => has_target_feature = false, _ => {} } } } } } if has_target_feature { println!("cargo:rustc-cfg=portable_atomic_target_feature=\"{}\"", name); } has_target_feature } fn target_cpu() -> Option { let rustflags = env::var_os("CARGO_ENCODED_RUSTFLAGS")?; let rustflags = rustflags.to_string_lossy(); let mut cpu = None; for mut flag in rustflags.split('\x1f') { flag = strip_prefix(flag, "-C").unwrap_or(flag); if let Some(flag) = strip_prefix(flag, "target-cpu=") { cpu = Some(flag); } } cpu.map(str::to_owned) } fn is_allowed_feature(name: &str) -> bool { // https://github.com/dtolnay/thiserror/pull/248 if env::var_os("RUSTC_STAGE").is_some() { return false; } // allowed by default let mut allowed = true; if let Some(rustflags) = env::var_os("CARGO_ENCODED_RUSTFLAGS") { for mut flag in rustflags.to_string_lossy().split('\x1f') { flag = strip_prefix(flag, "-Z").unwrap_or(flag); if let Some(flag) = strip_prefix(flag, "allow-features=") { // If it is specified multiple times, the last value will be preferred. allowed = flag.split(',').any(|allowed| allowed == name); } } } allowed } // Adapted from https://github.com/crossbeam-rs/crossbeam/blob/crossbeam-utils-0.8.14/build-common.rs. // // The target triplets have the form of 'arch-vendor-system'. // // When building for Linux (e.g. the 'system' part is // 'linux-something'), replace the vendor with 'unknown' // so that mapping to rust standard targets happens correctly. fn convert_custom_linux_target(target: &str) -> String { let mut parts: Vec<&str> = target.split('-').collect(); let system = parts.get(2); if system == Some(&"linux") { parts[1] = "unknown"; } parts.join("-") } // str::strip_prefix requires Rust 1.45 #[must_use] fn strip_prefix<'a>(s: &'a str, pat: &str) -> Option<&'a str> { if s.starts_with(pat) { Some(&s[pat.len()..]) } else { None } } // str::strip_suffix requires Rust 1.45 #[must_use] fn strip_suffix<'a>(s: &'a str, pat: &str) -> Option<&'a str> { if s.ends_with(pat) { Some(&s[..s.len() - pat.len()]) } else { None } }