// SPDX-License-Identifier: Apache-2.0 OR MIT

// The rustc-cfg emitted by the build script are *not* public API.

// version.rs is shared with portable-atomic's build script, and portable-atomic-util only uses a part of it.
#[allow(dead_code)]
#[path = "version.rs"]
mod version;
use version::{rustc_version, Version};

use std::env;

fn main() {
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rerun-if-changed=version.rs");

    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 {
        // 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_no_alloc,portable_atomic_no_alloc_layout_extras,portable_atomic_no_core_unwind_safe,portable_atomic_no_error_in_core,portable_atomic_no_futures_api,portable_atomic_no_io_safety,portable_atomic_no_io_vec,portable_atomic_no_maybe_uninit,portable_atomic_no_min_const_generics,portable_atomic_no_track_caller,portable_atomic_no_unsafe_op_in_unsafe_fn,portable_atomic_sanitize_thread)"
        );
    }

    // 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.

    // alloc stabilized in Rust 1.36 (nightly-2019-04-15) https://github.com/rust-lang/rust/pull/59675
    if !version.probe(36, 2019, 4, 14) {
        println!("cargo:rustc-cfg=portable_atomic_no_alloc");
    }
    // std::{future,task} stabilized in Rust 1.36 (nightly-2019-04-25) https://github.com/rust-lang/rust/pull/59739
    if !version.probe(36, 2019, 4, 24) {
        println!("cargo:rustc-cfg=portable_atomic_no_futures_api");
    }
    // {read,write}_vectored stabilized in Rust 1.36 (nightly-2019-04-30) https://github.com/rust-lang/rust/pull/60334
    if !version.probe(36, 2019, 4, 29) {
        println!("cargo:rustc-cfg=portable_atomic_no_io_vec");
    }
    // MaybeUninit stabilized in Rust 1.36 (nightly-2019-05-21) https://github.com/rust-lang/rust/pull/60445
    if !version.probe(36, 2019, 5, 20) {
        println!("cargo:rustc-cfg=portable_atomic_no_maybe_uninit");
    }
    // Layout::{align_to,pad_to_align,extend,array} stabilized in Rust 1.44 (nightly-2020-04-22) https://github.com/rust-lang/rust/pull/69362
    if !version.probe(44, 2020, 4, 21) {
        println!("cargo:rustc-cfg=portable_atomic_no_alloc_layout_extras");
    }
    // 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");
    }
    // min_const_generics stabilized in Rust 1.51 (nightly-2020-12-28): https://github.com/rust-lang/rust/pull/79135
    if !version.probe(51, 2020, 12, 27) {
        println!("cargo:rustc-cfg=portable_atomic_no_min_const_generics");
    }
    // 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");
    }
    // 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");
    }
    // io_safety stabilized in Rust 1.63 (nightly-2022-06-16): https://github.com/rust-lang/rust/pull/95118
    if !version.probe(63, 2022, 6, 15) {
        println!("cargo:rustc-cfg=portable_atomic_no_io_safety");
    }
    // error_in_core stabilized in Rust 1.81 (nightly-2024-06-09): https://github.com/rust-lang/rust/pull/125951
    if !version.probe(81, 2024, 6, 8) {
        println!("cargo:rustc-cfg=portable_atomic_no_error_in_core");
    }

    if version.nightly {
        // `cfg(sanitize = "..")` is not stabilized.
        let sanitize = env::var("CARGO_CFG_SANITIZE").unwrap_or_default();
        if sanitize.contains("thread") {
            println!("cargo:rustc-cfg=portable_atomic_sanitize_thread");
        }
    }
}