Added optional semver matching for libcamera bindings

Author: dbartussek

libcamera/Cargo.toml

@@ -11,7 +11,10 @@ categories = ["api-bindings", "computer-vision", "multimedia"]
 readme = "../README.md"
 
 [features]
-default = ["vendor_draft"]
+default = ["vendor_draft", "libcamera_semver_versioning"]
+
+libcamera_semver_versioning = []
+
 vendor_draft = []
 vendor_rpi = []
 
@@ -26,3 +29,4 @@ thiserror = "1.0"
 
 [build-dependencies]
 libcamera-sys = { path = "../libcamera-sys", version = "0.2.3" }
+semver = "1.0.22"

libcamera/build.rs

@@ -3,23 +3,62 @@ use std::{
     path::{Path, PathBuf},
 };
 
+use semver::{Comparator, Op, Version};
+
 fn main() {
-    let version = format!(
-        "{}.{}.{}",
-        libcamera_sys::LIBCAMERA_VERSION_MAJOR,
-        libcamera_sys::LIBCAMERA_VERSION_MINOR,
-        libcamera_sys::LIBCAMERA_VERSION_PATCH
+    let libcamera_version = Version::new(
+        libcamera_sys::LIBCAMERA_VERSION_MAJOR as _,
+        libcamera_sys::LIBCAMERA_VERSION_MINOR as _,
+        libcamera_sys::LIBCAMERA_VERSION_PATCH as _,
     );
 
-    let versioned_files = Path::new("versioned_files").join(&version);
+    let versioned_files = Path::new("versioned_files");
+    let mut candidates = std::fs::read_dir(versioned_files)
+        .unwrap()
+        .filter_map(|entry| entry.ok())
+        .filter_map(|entry| {
+            let path = entry.path();
+            let version = Version::parse(path.file_name()?.to_str()?).ok()?;
 
-    if std::fs::metadata(&versioned_files).is_err() {
-        panic!("Unsupported version of libcamera detected: {version}");
-    }
+            Some((version, path))
+        })
+        .collect::<Vec<_>>();
+    candidates.sort_unstable_by_key(|(version, _)| version.clone());
+
+    // Filter to only compatible versions
+    let matching = candidates.iter().filter(|(candidate, _)| {
+        #[cfg(feature = "libcamera_semver_versioning")]
+        let op = Op::Caret;
+        #[cfg(not(feature = "libcamera_semver_versioning"))]
+        let op = Op::Exact;
+
+        let comparator = Comparator {
+            op,
+            major: candidate.major,
+            minor: Some(candidate.minor),
+            patch: Some(candidate.patch),
+            pre: Default::default(),
+        };
+
+        comparator.matches(&libcamera_version)
+    });
+
+    // And take the most recent compatible version
+    let (_, selected_version) = match matching.max_by_key(|(version, _)| version.clone()) {
+        Some(v) => v,
+        None => panic!(
+            "Unsupported version of libcamera detected: {libcamera_version}\nsupported versions are: \n{}",
+            candidates
+                .iter()
+                .map(|(v, _)| format!("\t{v}"))
+                .collect::<Vec<_>>()
+                .join("\n")
+        ),
+    };
 
     let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
 
     for file in ["controls.rs", "properties.rs"] {
-        std::fs::copy(versioned_files.join(file), out_path.join(file)).unwrap();
+        std::fs::copy(selected_version.join(file), out_path.join(file)).unwrap();
     }
 }