Merge branch 'build/bindgen-cleanup' into 'master'

build: Build and bindings cleanups

See merge request videolan/vlc-rs!17

.cargo/config.toml

@@ -0,0 +1,2 @@
+[alias]
+xtask = "run --manifest-path xtask/Cargo.toml --"

.gitignore

@@ -13,4 +13,5 @@
 # Generated by Cargo
 /target/
 /libvlc-sys/target
+/xtask/target
 Cargo.lock

Cargo.toml

@@ -11,7 +11,8 @@ repository = "https://code.videolan.org/videolan/vlc-rs"
 homepage = "https://code.videolan.org/videolan/vlc-rs"
 license = "MIT"
 readme = "README.md"
-edition = "2018"
+edition = "2021"
+rust-version = "1.82"
 
 [lib]
 name = "vlc"
@@ -21,6 +22,7 @@ crate-type = ["rlib"]
 libc = "0.2"
 libvlc-sys = { path = "libvlc-sys" }
 
-[features]
-default = []
-use-bindgen = ["libvlc-sys/use-bindgen"]
+# `xtask` contains maintenance tools; keep it out of the workspace so normal
+# builds never compile it.
+[workspace]
+exclude = ["xtask"]

libvlc-sys/Cargo.toml

@@ -10,7 +10,8 @@ documentation = "https://docs.rs/vlc-rs"
 repository = "https://code.videolan.org/videolan/vlc-rs"
 homepage = "https://code.videolan.org/videolan/vlc-rs"
 license = "MIT"
-edition = "2018"
+edition = "2021"
+rust-version = "1.82"
 build = "build.rs"
 
 [lib]
@@ -21,12 +22,7 @@ crate-type = ["rlib"]
 libc = "0.2"
 
 [build-dependencies]
-bindgen = {version = "0.59", optional = true }
 pkg-config = "0.3"
 
 [target.'cfg(target_os = "windows")'.build-dependencies]
 vswhom = "0.1.0"
-
-[features]
-default = []
-use-bindgen = ["bindgen"]

libvlc-sys/build.rs

@@ -1,55 +1,12 @@
-use std::env;
-use std::path::PathBuf;
-use pkg_config;
+//! Build script for `libvlc-sys`, locates and links libvlc.
 
-#[cfg(feature = "bindgen")]
-fn generate_bindings() {
-    println!("cargo:rerun-if-changed=wrapper.h");
+/// Minimum supported libvlc version.
+const MIN_LIBVLC_VERSION: &str = "3.0.0";
 
-    let mut bindings = bindgen::Builder::default()
-        .header("wrapper.h")
-        // For no_std
-        .use_core()
-        // Use libc
-        .ctypes_prefix("libc")
-        // Whitelist
-        .whitelist_type(".*vlc.*")
-        .whitelist_function(".*vlc.*")
-        .whitelist_var(".*vlc.*")
-        .whitelist_function("vsnprintf")
-        .parse_callbacks(Box::new(bindgen::CargoCallbacks));
-
-    // Set header include paths
-    let pkg_config_library = pkg_config::Config::new().probe("libvlc").unwrap();
-    for include_path in &pkg_config_library.include_paths {
-        bindings = bindings.clang_arg(format!("-I{}", include_path.display()));
-    }
-
-    let bindings = bindings.generate().expect("Unable to generate bindings");
-
-    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
-    bindings
-        .write_to_file(out_path.join("bindings.rs"))
-        .expect("Couldn't write bindings!");
-}
-
-#[cfg(not(feature = "bindgen"))]
-fn copy_pregenerated_bindings()
-{
-    use std::fs;
-
-    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let crate_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
-    fs::copy(
-        crate_path.join("bindings.rs"),
-        out_path.join("bindings.rs"),
-    )
-    .expect("Couldn't find pregenerated bindings!");
-}
-
-fn link_vlc_with_pkgconfig() -> Result<pkg_config::Library, pkg_config::Error> {
+/// Locate libvlc via pkg-config.
+fn probe_libvlc() -> Result<pkg_config::Library, pkg_config::Error> {
     pkg_config::Config::new()
-        .print_system_libs(false)
+        .atleast_version(MIN_LIBVLC_VERSION)
         .probe("libvlc")
 }
 
@@ -139,8 +96,11 @@ mod windows {
                     }
                 ),
             ])
-            .spawn()
-            .unwrap();
+            .status()
+            .expect("Failed to run lib.exe")
+            .success()
+            .then_some(())
+            .expect("lib.exe failed to generate the vlc import library");
     }
 
     fn vlc_path() -> PathBuf {
@@ -163,21 +123,13 @@ mod windows {
 }
 
 fn main() {
-    // Binding generation
-    #[cfg(feature = "bindgen")]
-    generate_bindings();
-
-    #[cfg(not(feature = "bindgen"))]
-    copy_pregenerated_bindings();
-
-    // Link
-    if let Err(err) = link_vlc_with_pkgconfig() {
+    // On success pkg-config has already emitted the link directives; only the
+    // failure path needs handling.
+    if let Err(err) = probe_libvlc() {
         #[cfg(target_os = "windows")]
         windows::link_vlc();
 
         #[cfg(not(target_os = "windows"))]
-        panic!("libvlc not found: {:?}", err);
+        panic!("libvlc (>= {}) not found: {:?}", MIN_LIBVLC_VERSION, err);
     }
-
-    println!("cargo:rustc-link-lib=vlc");
 }

libvlc-sys/src/lib.rs

@@ -3,4 +3,6 @@
 #![allow(non_snake_case)]
 #![no_std]
 
-include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
+// The bindings are a committed source file, regenerated out of band with
+// `cargo xtask bindgen`.
+include!("../bindings.rs");

xtask/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "xtask"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+bindgen = "0.72"
+pkg-config = "0.3"
+
+# Standalone from the vlc-rs workspace, kept out of the normal build graph.
+[workspace]

xtask/src/main.rs

@@ -0,0 +1,70 @@
+//! Maintenance tasks for vlc-rs, invoked via `cargo xtask <task>`.
+
+use std::path::{Path, PathBuf};
+use std::process::ExitCode;
+
+/// Minimum libvlc version the bindings target. Keep in sync with
+/// `libvlc-sys/build.rs`.
+const MIN_LIBVLC_VERSION: &str = "3.0.0";
+
+fn main() -> ExitCode {
+    match std::env::args().nth(1).as_deref() {
+        Some("bindgen") => {
+            generate_bindings();
+            ExitCode::SUCCESS
+        }
+        _ => {
+            eprintln!("usage: cargo xtask <task>\n");
+            eprintln!("tasks:");
+            eprintln!("    bindgen    regenerate libvlc-sys/bindings.rs from the system libvlc headers");
+            ExitCode::FAILURE
+        }
+    }
+}
+
+fn generate_bindings() {
+    let sys_dir = libvlc_sys_dir();
+    let header = sys_dir.join("wrapper.h");
+    let output = sys_dir.join("bindings.rs");
+
+    // Enforce the same minimum version the build script requires and pick up any
+    // header search paths.
+    let library = pkg_config::Config::new()
+        .atleast_version(MIN_LIBVLC_VERSION)
+        .cargo_metadata(false)
+        .probe("libvlc")
+        .unwrap_or_else(|e| panic!("libvlc >= {MIN_LIBVLC_VERSION} not found via pkg-config: {e}"));
+
+    let mut bindings = bindgen::Builder::default()
+        .header(header.to_str().expect("non-UTF-8 header path"))
+        // For no_std
+        .use_core()
+        // Use libc
+        .ctypes_prefix("libc")
+        // Allowlist every (lib)vlc symbol.
+        .allowlist_item("(lib|LIB)?(vlc|VLC)_.*")
+        // Required by the Windows `legacy_stdio_definitions` link workaround
+        // (see libvlc-sys/build.rs).
+        .allowlist_function("vsnprintf");
+
+    for path in &library.include_paths {
+        bindings = bindings.clang_arg(format!("-I{}", path.display()));
+    }
+
+    let generated = bindings
+        .generate()
+        .expect("unable to generate bindings")
+        .to_string();
+
+    std::fs::write(&output, generated).expect("couldn't write bindings");
+    println!("wrote {}", output.display());
+}
+
+/// Absolute path to the `libvlc-sys` crate directory, derived from this xtask's
+/// location so it works regardless of the current working directory.
+fn libvlc_sys_dir() -> PathBuf {
+    Path::new(env!("CARGO_MANIFEST_DIR"))
+        .parent()
+        .expect("xtask has no parent directory")
+        .join("libvlc-sys")
+}