From fc627faf5eb7971d90449eb094f280e3410b250a Mon Sep 17 00:00:00 2001
From: Zach Vorhies <zachvorhies@protonmail.com>
Date: Sun, 13 Sep 2026 03:19:01 -0700
Subject: [PATCH] feat: expose binary compile-target identity (refs #190)

---
 src/platform/host.rs    | 25 +++++++++++++++++++++++++
 tests/process_target.rs | 18 ++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 tests/process_target.rs

diff --git a/src/platform/host.rs b/src/platform/host.rs
index b53b4450..8b8b3c3d 100644
--- a/src/platform/host.rs
+++ b/src/platform/host.rs
@@ -20,6 +20,31 @@ pub use crate::{
 
 pub use crate::host_login_environment_block as login_environment_block;
 
+/// Compile target of this executing binary, not the physical host hardware.
+///
+/// Names follow Rust's target vocabulary (for example `windows`, `macos`,
+/// `linux`, `x86_64`, and `aarch64`). Package registry aliases and supported
+/// artifact selection are caller policy.
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub struct ProcessTarget {
+    /// Operating system the binary was compiled for.
+    pub os: &'static str,
+    /// Architecture the binary was compiled for.
+    pub architecture: &'static str,
+}
+
+/// Report the executing binary's compile target without probing the host.
+///
+/// An x86-64 binary running under emulation on ARM64 still reports `x86_64`.
+/// This does not detect Rosetta, CPU features, the host's native architecture,
+/// or ABI details such as libc. No subprocess or environment lookup is used.
+pub const fn process_target() -> ProcessTarget {
+    ProcessTarget {
+        os: std::env::consts::OS,
+        architecture: std::env::consts::ARCH,
+    }
+}
+
 /// Logical concurrency this host exposes to this process.
 ///
 /// A thin, host-neutral restatement of [`std::thread::available_parallelism`]
diff --git a/tests/process_target.rs b/tests/process_target.rs
new file mode 100644
index 00000000..e38cd4c9
--- /dev/null
+++ b/tests/process_target.rs
@@ -0,0 +1,18 @@
+use kernal_api::platform::host::{process_target, ProcessTarget};
+
+#[test]
+fn process_target_reports_binary_target_without_host_probing() {
+    const TARGET: ProcessTarget = process_target();
+    assert_eq!(TARGET.os, std::env::consts::OS);
+    assert_eq!(TARGET.architecture, std::env::consts::ARCH);
+    #[cfg(target_os = "windows")]
+    assert_eq!(TARGET.os, "windows");
+    #[cfg(target_os = "macos")]
+    assert_eq!(TARGET.os, "macos");
+    #[cfg(target_os = "linux")]
+    assert_eq!(TARGET.os, "linux");
+    #[cfg(target_arch = "x86_64")]
+    assert_eq!(TARGET.architecture, "x86_64");
+    #[cfg(target_arch = "aarch64")]
+    assert_eq!(TARGET.architecture, "aarch64");
+}