support prebuilt library binaries

Cargo.toml

@@ -36,13 +36,26 @@ documentation.workspace = true
 readme = "README.md"
 
 [dependencies]
+system-deps-meta = { workspace = true, optional = true }
 pkg-config = "0.3.25"
 toml = { version = "0.8", default-features = false, features = ["parse"] }
 version-compare = "0.2"
 heck = "0.5"
 cfg-expr = { version = "0.17", features = ["targets"] }
 
+[build-dependencies]
+system-deps-meta = { workspace = true, optional = true }
+
 [dev-dependencies]
-lazy_static = "1"
+system-deps-meta = { workspace = true, features = ["test"] }
 itertools = "0.13"
 assert_matches = "1.5"
+tiny_http = "0.12"
+
+[features]
+default = [ ]
+# How to do this using resolver v2? Since features are separated
+binary = [ "system-deps-meta/binary" ]
+gz = [ "system-deps-meta/gz" ]
+xz = [ "system-deps-meta/xz" ]
+zip = [ "system-deps-meta/zip" ]

build.rs

@@ -0,0 +1,32 @@
+pub fn main() {
+    #[cfg(feature = "binary")]
+    binary::build().unwrap_or_else(|e| panic!("{}", e));
+}
+
+#[cfg(feature = "binary")]
+mod binary {
+    use std::{fs, path::Path};
+
+    use system_deps_meta::{
+        binary::{merge_binary, Paths},
+        error::{BinaryError, Error},
+        parse::read_metadata,
+        BUILD_MANIFEST, BUILD_TARGET_DIR,
+    };
+
+    // Add pkg-config paths to the overrides
+    pub fn build() -> Result<(), Error> {
+        // Read metadata from the crate graph
+        let metadata = read_metadata(BUILD_MANIFEST, "system-deps", merge_binary)?;
+
+        // Download the binaries and get their pkg_config paths
+        let paths: Paths = metadata.into_iter().collect();
+
+        // Write the binary paths to a file for later use
+        let dest = Path::new(BUILD_TARGET_DIR).join("paths.toml");
+        fs::write(&dest, paths.to_string()?).map_err(BinaryError::InvalidDirectory)?;
+        println!("cargo:rustc-env=BINARY_PATHS={}", dest.display());
+
+        Ok(())
+    }
+}