Function linking_with_pkg_config

build.rs:301–327

Returns error when some library are missing. Otherwise, returns the paths of the libraries. Note: no side effect if this function errors.

(
        library_names: &[&str],
    )

    ///
    /// Note: no side effect if this function errors.
    pub fn linking_with_pkg_config(
        library_names: &[&str],
    ) -> Result<Vec<PathBuf>, pkg_config::Error> {
        // dry run for library linking
        for libname in library_names {
            pkg_config::Config::new()
                .cargo_metadata(false)
                .env_metadata(false)
                .print_system_libs(false)
                .print_system_cflags(false)
                .probe(&format!("lib{}", libname))?;
        }

        // real linking
        let mut paths = HashSet::new();
        for libname in library_names {
            let new_paths = pkg_config::Config::new()
                .probe(&format!("lib{}", libname))
                .unwrap_or_else(|_| panic!("{} not found!", libname))
                .include_paths;
            for new_path in new_paths {
                let new_path = new_path.to_str().unwrap().to_string();
                paths.insert(new_path);
            }
        }
        Ok(paths.into_iter().map(PathBuf::from).collect())
    }
}

#[cfg(feature = "link_vcpkg_ffmpeg")]