Refactor: Use links, Error types and group code

Cargo.toml

@@ -10,6 +10,7 @@ exclude = ["/.github"]
 keywords = ["ffi", "cd", "cdio", "iso9660", "udf"]
 categories = ["external-ffi-bindings", "hardware-support", "multimedia", "multimedia::audio"]
 license = "GPL-3.0+"
+links = "cdio"
 
 [build-dependencies]
 bindgen = "0.72"

build.rs

@@ -1,60 +1,50 @@
 use std::env;
+use std::error::Error;
 use std::path::PathBuf;
 
-// libcdio uses a homegrown boolean type for versions < 2.1.1.
-// The homegrown boolean type is not recognized by bindgen.
-// This would result in different code gen for versions < 2.1.1 and versions >= 2.1.1.
-// To prevent this, we include stdbool.h ourselves, which suppresses the homegrown boolean type.
-const CDIO_HEADER: &str = "#include <stdbool.h>
-#include <cdio/cdio.h>
-#include <cdio/cd_types.h>
-#include <cdio/logging.h>
-#include <cdio/mmc_cmds.h>
-#include <cdio/utf8.h>\n";
+fn main() -> Result<(), Box<dyn Error>> {
+    system_deps::Config::new().probe()?;
+    make_bindings()?;
 
-#[cfg(feature = "iso9660")]
-const ISO9660_HEADER: &str = "#include <cdio/iso9660.h>\n";
-
-#[cfg(feature = "udf")]
-const UDF_HEADER: &str = "#include <cdio/udf.h>\n";
-
-#[cfg(feature = "cdda")]
-const CDDA_HEADER: &str = "#include <cdio/paranoia/cdda.h>\n";
-
-#[cfg(feature = "paranoia")]
-const PARANOIA_HEADER: &str = "#include <cdio/paranoia/paranoia.h>\n";
-
-const HEADERS: &[&str] = &[
-    CDIO_HEADER,
-    #[cfg(feature = "iso9660")]
-    ISO9660_HEADER,
-    #[cfg(feature = "udf")]
-    UDF_HEADER,
-    #[cfg(feature = "cdda")]
-    CDDA_HEADER,
-    #[cfg(feature = "paranoia")]
-    PARANOIA_HEADER,
-];
-
-fn main() {
-    if let Err(s) = system_deps::Config::new().probe() {
-        println!("cargo:warning={s}");
-        std::process::exit(1);
-    }
+    Ok(())
+}
 
-    let headers = HEADERS.join("");
+fn make_bindings() -> Result<(), Box<dyn Error>> {
+    // libcdio uses a homegrown boolean type for versions < 2.1.1.
+    // The homegrown boolean type is not recognized by bindgen.
+    // This would result in different code gen for versions < 2.1.1 and versions >= 2.1.1.
+    // To prevent this, we include stdbool.h ourselves, which suppresses the homegrown boolean type.
+    static CDIO_HEADERS: &str = r"
+        #include <stdbool.h>
+        #include <cdio/cdio.h>
+        #include <cdio/cd_types.h>
+        #include <cdio/logging.h>
+        #include <cdio/mmc_cmds.h>
+        #include <cdio/utf8.h>
+";
+    static HEADERS: &[&str] = &[
+        CDIO_HEADERS,
+        #[cfg(feature = "iso9660")]
+        "#include <cdio/iso9660.h>",
+        #[cfg(feature = "udf")]
+        "#include <cdio/udf.h>",
+        #[cfg(feature = "cdda")]
+        "#include <cdio/paranoia/cdda.h>",
+        #[cfg(feature = "paranoia")]
+        "#include <cdio/paranoia/paranoia.h>",
+    ];
+    let headers = HEADERS.join("\n");
     let bindings = bindgen::Builder::default()
         .header_contents("wrapper.h", &headers)
         .allowlist_file(r".*[/\\]cdio[/\\][^/\\]*\.h")
         .allowlist_file(r".*[/\\]cdio[/\\]paranoia[/\\][^/\\]*\.h")
         .wrap_unsafe_ops(true)
         .parse_callbacks(Box::new(bindgen::CargoCallbacks::new()))
-        .generate()
-        .expect("Unable to generate bindings");
+        .generate()?;
 
-    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    let out_path =
+        PathBuf::from(env::var("OUT_DIR").expect("OUT_DIR should have been set by Cargo"));
+    bindings.write_to_file(out_path.join("bindings.rs"))?;
 
-    bindings
-        .write_to_file(out_path.join("bindings.rs"))
-        .expect("Couldn't write bindings!");
+    Ok(())
 }