1 files changed, 195 insertions, 0 deletions
diff --git a/subprojects/thiserror/build.rs b/subprojects/thiserror/build.rs
new file mode 100644
index 0000000..d1558fb
--- /dev/null
+++ b/subprojects/thiserror/build.rs
@@ -0,0 +1,195 @@
+use std::env;
+use std::ffi::OsString;
+use std::fs;
+use std::io::ErrorKind;
+use std::iter;
+use std::path::{Path, PathBuf};
+use std::process::{self, Command, Stdio};
+use std::str;
+
+const PRIVATE: &str = "\
+#[doc(hidden)]
+pub mod __private$$ {
+    #[doc(hidden)]
+    pub use crate::private::*;
+}
+";
+
+fn main() {
+    println!("cargo:rerun-if-changed=build/probe.rs");
+
+    println!("cargo:rustc-check-cfg=cfg(error_generic_member_access)");
+    println!("cargo:rustc-check-cfg=cfg(thiserror_nightly_testing)");
+    println!("cargo:rustc-check-cfg=cfg(thiserror_no_backtrace_type)");
+
+    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    let patch_version = env::var("CARGO_PKG_VERSION_PATCH").unwrap();
+    let module = PRIVATE.replace("$$", &patch_version);
+    fs::write(out_dir.join("private.rs"), module).unwrap();
+
+    let error_generic_member_access;
+    let consider_rustc_bootstrap;
+    if compile_probe(false) {
+        // This is a nightly or dev compiler, so it supports unstable features
+        // regardless of RUSTC_BOOTSTRAP. No need to rerun build script if
+        // RUSTC_BOOTSTRAP is changed.
+        error_generic_member_access = true;
+        consider_rustc_bootstrap = false;
+    } else if let Some(rustc_bootstrap) = env::var_os("RUSTC_BOOTSTRAP") {
+        if compile_probe(true) {
+            // This is a stable or beta compiler for which the user has set
+            // RUSTC_BOOTSTRAP to turn on unstable features. Rerun build script
+            // if they change it.
+            error_generic_member_access = true;
+            consider_rustc_bootstrap = true;
+        } else if rustc_bootstrap == "1" {
+            // This compiler does not support the generic member access API in
+            // the form that thiserror expects. No need to pay attention to
+            // RUSTC_BOOTSTRAP.
+            error_generic_member_access = false;
+            consider_rustc_bootstrap = false;
+        } else {
+            // This is a stable or beta compiler for which RUSTC_BOOTSTRAP is
+            // set to restrict the use of unstable features by this crate.
+            error_generic_member_access = false;
+            consider_rustc_bootstrap = true;
+        }
+    } else {
+        // Without RUSTC_BOOTSTRAP, this compiler does not support the generic
+        // member access API in the form that thiserror expects, but try again
+        // if the user turns on unstable features.
+        error_generic_member_access = false;
+        consider_rustc_bootstrap = true;
+    }
+
+    if error_generic_member_access {
+        println!("cargo:rustc-cfg=error_generic_member_access");
+    }
+
+    if consider_rustc_bootstrap {
+        println!("cargo:rerun-if-env-changed=RUSTC_BOOTSTRAP");
+    }
+
+    // core::error::Error stabilized in Rust 1.81
+    // https://blog.rust-lang.org/2024/09/05/Rust-1.81.0.html#coreerrorerror
+    let rustc = rustc_minor_version();
+    if cfg!(not(feature = "std")) && rustc.map_or(false, |rustc| rustc < 81) {
+        println!("cargo:rustc-cfg=feature=\"std\"");
+    }
+
+    let Some(rustc) = rustc else {
+        return;
+    };
+
+    // std::backtrace::Backtrace stabilized in Rust 1.65
+    // https://blog.rust-lang.org/2022/11/03/Rust-1.65.0.html#stabilized-apis
+    if rustc < 65 {
+        println!("cargo:rustc-cfg=thiserror_no_backtrace_type");
+    }
+}
+
+fn compile_probe(rustc_bootstrap: bool) -> bool {
+    if env::var_os("RUSTC_STAGE").is_some() {
+        // We are running inside rustc bootstrap. This is a highly non-standard
+        // environment with issues such as:
+        //
+        //     https://github.com/rust-lang/cargo/issues/11138
+        //     https://github.com/rust-lang/rust/issues/114839
+        //
+        // Let's just not use nightly features here.
+        return false;
+    }
+
+    let rustc = cargo_env_var("RUSTC");
+    let out_dir = cargo_env_var("OUT_DIR");
+    let out_subdir = Path::new(&out_dir).join("probe");
+    let probefile = Path::new("build").join("probe.rs");
+
+    if let Err(err) = fs::create_dir(&out_subdir) {
+        if err.kind() != ErrorKind::AlreadyExists {
+            eprintln!("Failed to create {}: {}", out_subdir.display(), err);
+            process::exit(1);
+        }
+    }
+
+    let rustc_wrapper = env::var_os("RUSTC_WRAPPER").filter(|wrapper| !wrapper.is_empty());
+    let rustc_workspace_wrapper =
+        env::var_os("RUSTC_WORKSPACE_WRAPPER").filter(|wrapper| !wrapper.is_empty());
+    let mut rustc = rustc_wrapper
+        .into_iter()
+        .chain(rustc_workspace_wrapper)
+        .chain(iter::once(rustc));
+    let mut cmd = Command::new(rustc.next().unwrap());
+    cmd.args(rustc);
+
+    if !rustc_bootstrap {
+        cmd.env_remove("RUSTC_BOOTSTRAP");
+    }
+
+    cmd.stderr(Stdio::null())
+        .arg("--edition=2018")
+        .arg("--crate-name=thiserror")
+        .arg("--crate-type=lib")
+        .arg("--cap-lints=allow")
+        .arg("--emit=dep-info,metadata")
+        .arg("--out-dir")
+        .arg(&out_subdir)
+        .arg(probefile);
+
+    if let Some(target) = env::var_os("TARGET") {
+        cmd.arg("--target").arg(target);
+    }
+
+    // If Cargo wants to set RUSTFLAGS, use that.
+    if let Ok(rustflags) = env::var("CARGO_ENCODED_RUSTFLAGS") {
+        if !rustflags.is_empty() {
+            for arg in rustflags.split('\x1f') {
+                cmd.arg(arg);
+            }
+        }
+    }
+
+    let success = match cmd.status() {
+        Ok(status) => status.success(),
+        Err(_) => false,
+    };
+
+    // Clean up to avoid leaving nondeterministic absolute paths in the dep-info
+    // file in OUT_DIR, which causes nonreproducible builds in build systems
+    // that treat the entire OUT_DIR as an artifact.
+    if let Err(err) = fs::remove_dir_all(&out_subdir) {
+        // libc::ENOTEMPTY
+        // Some filesystems (NFSv3) have timing issues under load where '.nfs*'
+        // dummy files can continue to get created for a short period after the
+        // probe command completes, breaking remove_dir_all.
+        // To be replaced with ErrorKind::DirectoryNotEmpty (Rust 1.83+).
+        const ENOTEMPTY: i32 = 39;
+
+        if !(err.kind() == ErrorKind::NotFound
+            || (cfg!(target_os = "linux") && err.raw_os_error() == Some(ENOTEMPTY)))
+        {
+            eprintln!("Failed to clean up {}: {}", out_subdir.display(), err);
+            process::exit(1);
+        }
+    }
+
+    success
+}
+
+fn rustc_minor_version() -> Option<u32> {
+    let rustc = cargo_env_var("RUSTC");
+    let output = Command::new(rustc).arg("--version").output().ok()?;
+    let version = str::from_utf8(&output.stdout).ok()?;
+    let mut pieces = version.split('.');
+    if pieces.next() != Some("rustc 1") {
+        return None;
+    }
+    pieces.next()?.parse().ok()
+}
+
+fn cargo_env_var(key: &str) -> OsString {
+    env::var_os(key).unwrap_or_else(|| {
+        eprintln!("Environment variable ${key} is not set during execution of build script");
+        process::exit(1);
+    })
+}