Kernel CONFIG cfg

[kloenk]

I tried to find out how to detect thinks like if CONFIG_DEBUG_KERNEL is set. As I did not see a way, I implemented this way, but not sure if its a good way to handle this things. There for I only create the diff here, and no pr yet. This just passes every CONFIG_* to rustc as a cfg.

diff --git a/rust/kernel/build.rs b/rust/kernel/build.rs
index 0897186b3f92..2818bcb1b391 100644
--- a/rust/kernel/build.rs
+++ b/rust/kernel/build.rs
@@ -92,6 +92,26 @@ fn main() {
     println!("cargo:rerun-if-env-changed=RUST_BINDGEN_CFLAGS");

     let kernel_dir = "../../";
+    println!("cargo:rerun-if-changed={}/include/config/auto.conf", kernel_dir);
+    let file = std::fs::File::open(format!("{}/include/config/auto.conf", kernel_dir)).expect("could not open kernel config");
+    let file = std::io::BufReader::new(file);
+    use std::io::BufRead;
+    for line in file.lines() {
+        let line = line.unwrap();
+        if !line.contains("=") {
+            continue;
+        }
+        let line: Vec<&str> = line.split("=").collect();
+        if line.len() != 2 {
+            panic!();
+        };
+        let key = line[0];
+        let value = line[1].trim_matches('"');
+
+        println!("cargo:rustc-cfg={}=\"{}\"", key, value);
+    };
+
+
     let cflags = env::var("RUST_BINDGEN_CFLAGS").expect("Must be invoked from kernel makefile");

     let kernel_args = prepare_cflags(&cflags, &kernel_dir);

[ojeda]

The config is already being passed to rustc via --cfg, although we may want to improve it, of course.