| // 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 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("zaamo","zabha","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_pre_llvm_15,portable_atomic_pre_llvm_16,portable_atomic_pre_llvm_18,portable_atomic_pre_llvm_19,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_raw_ptr_deref,portable_atomic_no_const_transmute,portable_atomic_no_core_unwind_safe,portable_atomic_no_diagnostic_namespace,portable_atomic_no_stronger_failure_ordering,portable_atomic_no_track_caller,portable_atomic_no_unsafe_op_in_unsafe_fn,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"); |
| } |
| // #[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"); |
| } |
| |
| // asm 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"); |
| } |
| |
| // 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 < 19 { |
| println!("cargo:rustc-cfg=portable_atomic_pre_llvm_19"); |
| 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). |
| // https://github.com/rust-lang/rust/pull/111331 merged in Rust 1.71 (nightly-2023-05-09). |
| if !no_asm |
| && (target_arch == "powerpc64" && version.probe(60, 2022, 2, 12) |
| || target_arch == "s390x" && version.probe(71, 2023, 5, 8) |
| || target_arch == "arm64ec") |
| && 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" => { |
| // As of rustc 1.80, target_feature "zaamo"/"zabha"/"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 |
| // zabha and zacas imply zaamo in GCC, but do not in LLVM (but enabling them without zaamo is not allowed). |
| // 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 |
| 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 |
| target_feature_fallback("zabha", false); |
| } |
| 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. |
| target_feature_fallback("experimental-zacas", false); |
| } |
| // amo*.{w,d} |
| target_feature_fallback("zaamo", false); |
| } |
| "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 has_pwr8_features = target_endian == "little"; |
| // https://github.com/llvm/llvm-project/commit/549e118e93c666914a1045fde38a2cac33e1e445 |
| 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::<u32>() { |
| has_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 |
| has_pwr8_features = cpu == "ppc64le" || cpu == "future"; |
| } |
| } |
| // lqarx and stqcx. |
| target_feature_fallback("quadword-atomics", has_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 |
| // 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); |
| // 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<u32>) -> 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<String> { |
| 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 |
| } |
| } |
