rust: move import of PathBuf

By moving it to the single function that uses it, we eliminate a
#cfg.

Differential Revision: https://phab.mercurial-scm.org/D1845

rust/hgcli/build.rs

@@ -1,128 +1,127 b''
 // build.rs -- Configure build environment for `hgcli` Rust package.
 //
 // Copyright 2017 Gregory Szorc <[e-mail]>
 //
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
 
 use std::collections::HashMap;
 use std::env;
 use std::path::Path;
-#[cfg(target_os = "windows")]
-use std::path::PathBuf;
-
 use std::process::Command;
 
 struct PythonConfig {
     python: String,
     config: HashMap<String, String>,
 }
 
 fn get_python_config() -> PythonConfig {
     // The python27-sys crate exports a Cargo variable defining the full
     // path to the interpreter being used.
     let python = env::var("DEP_PYTHON27_PYTHON_INTERPRETER").expect(
         "Missing DEP_PYTHON27_PYTHON_INTERPRETER; bad python27-sys crate?",
     );
 
     if !Path::new(&python).exists() {
         panic!(
             "Python interpreter {} does not exist; this should never happen",
             python
         );
     }
 
     // This is a bit hacky but it gets the job done.
     let separator = "SEPARATOR STRING";
 
     let script = "import sysconfig; \
 c = sysconfig.get_config_vars(); \
 print('SEPARATOR STRING'.join('%s=%s' % i for i in c.items()))";
 
     let mut command = Command::new(&python);
     command.arg("-c").arg(script);
 
     let out = command.output().unwrap();
 
     if !out.status.success() {
         panic!(
             "python script failed: {}",
             String::from_utf8_lossy(&out.stderr)
         );
     }
 
     let stdout = String::from_utf8_lossy(&out.stdout);
     let mut m = HashMap::new();
 
     for entry in stdout.split(separator) {
         let mut parts = entry.splitn(2, "=");
         let key = parts.next().unwrap();
         let value = parts.next().unwrap();
         m.insert(String::from(key), String::from(value));
     }
 
     PythonConfig {
         python: python,
         config: m,
     }
 }
 
 #[cfg(not(target_os = "windows"))]
 fn have_shared(config: &PythonConfig) -> bool {
     match config.config.get("Py_ENABLE_SHARED") {
         Some(value) => value == "1",
         None => false,
     }
 }
 
 #[cfg(target_os = "windows")]
 fn have_shared(config: &PythonConfig) -> bool {
+    use std::path::PathBuf;
+
     // python27.dll should exist next to python2.7.exe.
     let mut dll = PathBuf::from(&config.python);
     dll.pop();
     dll.push("python27.dll");
 
     return dll.exists();
 }
 
 const REQUIRED_CONFIG_FLAGS: [&'static str; 2] = ["Py_USING_UNICODE", "WITH_THREAD"];
 
 fn main() {
     let config = get_python_config();
 
     println!("Using Python: {}", config.python);
     println!("cargo:rustc-env=PYTHON_INTERPRETER={}", config.python);
 
     let prefix = config.config.get("prefix").unwrap();
 
     println!("Prefix: {}", prefix);
 
     // TODO Windows builds don't expose these config flags. Figure out another
     // way.
     #[cfg(not(target_os = "windows"))]
     for key in REQUIRED_CONFIG_FLAGS.iter() {
         let result = match config.config.get(*key) {
             Some(value) => value == "1",
             None => false,
         };
 
         if !result {
             panic!("Detected Python requires feature {}", key);
         }
     }
 
     // We need a Python shared library.
     if !have_shared(&config) {
         panic!("Detected Python lacks a shared library, which is required");
     }
 
     let ucs4 = match config.config.get("Py_UNICODE_SIZE") {
         Some(value) => value == "4",
         None => false,
     };
 
     if !ucs4 {
         #[cfg(not(target_os = "windows"))]
         panic!("Detected Python doesn't support UCS-4 code points");
     }
 }