Add all `libctru` files to rerun-if-changed

Also simplify version checking logic a bit. It's just a warning, so we
can check for exact version just to be safe and skip the major/minor
comparisons for semver.

Also update the README a bit to explain the versioning scheme.

README.md

@@ -5,8 +5,24 @@ A Rust wrapper library for smealum's [ctrulib](https://github.com/smealum/ctruli
 ## Structure
 
 This repository is organized as follows:
-* `ctru-rs`: Safe, idiomatic wrapper around `ctru-sys`.
-* `ctru-sys`: Low-level, unsafe bindings to ctrulib
+
+* `ctru-rs`: Safe, idiomatic wrapper around `ctru-sys`
+
+* `ctru-sys`: Low-level, unsafe bindings to ctrulib.
+
+  This crate's version changes according to the version of `libctru`
+  used to generate the bindings, with the following convention:
+
+  * `libctru` version `X.Y.Z-W`
+  * `ctru-sys` version `XY.Z.P+X.Y.Z-W`
+
+  where `P` is usually 0 but may be incremented for fixes in e.g.
+  binding generation, `libc` dependency bump, etc.
+
+  It may be possible to build this crate against a different version of `libctru`,
+  but you may encounter linker errors or ABI issues. A build-time Cargo warning
+  (displayed when built with `-vv`) will be issued if the build script detects
+  a mismatch or is unable to check the installed `libctru` version.
 
 ## License
 
@@ -37,3 +53,4 @@ applies to every file in the tree, unless otherwise noted.
 Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
 
 See [LICENSE-APACHE](https://github.com/rust-lang/rust/blob/master/LICENSE-APACHE), [LICENSE-MIT](https://github.com/rust-lang/rust/blob/master/LICENSE-MIT), and [COPYRIGHT](https://github.com/rust-lang/rust/blob/master/COPYRIGHT) for details.
+

ctru-sys/build.rs

@@ -27,9 +27,6 @@ fn main() {
             println!("cargo:rustc-env=LIBCTRU_MAJOR={maj}");
             println!("cargo:rustc-env=LIBCTRU_MINOR={min}");
             println!("cargo:rustc-env=LIBCTRU_PATCH={patch}");
-
-            // It would be nice if we could rerun-if-changed on libctru itself,
-            // maybe we can write a file to OUT_DIR and check that file?
         }
         Err(err) => println!("cargo:warning=failed to check libctru version: {err}"),
     }
@@ -50,7 +47,7 @@ fn parse_version(version: &str) -> Result<(String, String, String), &str> {
 fn check_libctru_version() -> Result<(String, String, String), Box<dyn Error>> {
     let pacman = which::which("dkp-pacman").or_else(|_| which::which("pacman"))?;
 
-    let Output { stdout, .. } = Command::new(pacman)
+    let Output { stdout, .. } = Command::new(&pacman)
         .args(["--query", "libctru"])
         .stderr(Stdio::inherit())
         .output()?;
@@ -59,26 +56,33 @@ fn check_libctru_version() -> Result<(String, String, String), Box<dyn Error>> {
 
     let (_pkg, lib_version) = output_str
         .split_once(char::is_whitespace)
-        .ok_or("unexpected output format")?;
+        .ok_or("unexpected pacman output format")?;
+
+    let lib_version = lib_version.trim();
 
     let cargo_pkg_version = env::var("CARGO_PKG_VERSION").unwrap();
     let (_, crate_built_version) = cargo_pkg_version
         .split_once('+')
         .expect("crate version should have '+' delimeter");
 
-    let (lib_major, lib_minor, lib_patch) = parse_version(lib_version)?;
-    let (crate_supported_major, crate_supported_minor, _crate_supported_patch) =
-        parse_version(crate_built_version)?;
-
-    // TODO: does == comparison make sense, or should we use >= or something?
-    if crate_supported_major != lib_major || crate_supported_minor != lib_minor {
-        // TODO: should this be a panic (i.e. induce build failure)? Maybe only for major version?
-
+    if lib_version != crate_built_version {
         return Err(format!(
-            "libctru version is {lib_major}.{lib_minor}.{lib_patch}, \
-            but this crate only supports {crate_supported_major}.{crate_supported_minor}.x"
+            "libctru version is {lib_version} but this crate was built for {crate_built_version}"
         ))?;
     }
 
+    let Output { stdout, .. } = Command::new(pacman)
+        .args(["--query", "--list", "libctru"])
+        .stderr(Stdio::inherit())
+        .output()?;
+
+    for line in String::from_utf8_lossy(&stdout).split('\n') {
+        let Some((_pkg, file)) = line.split_once(char::is_whitespace)
+        else { continue };
+
+        println!("cargo:rerun-if-changed={file}");
+    }
+
+    let (lib_major, lib_minor, lib_patch) = parse_version(lib_version)?;
     Ok((lib_major, lib_minor, lib_patch))
 }