1 use std::env;
2 use std::env::VarError;
3 use std::fs::File;
4 use std::io::Read;
5 use std::io::Write;
6 use std::path::Path;
7 use std::path::PathBuf;
8 use std::process;
9
10 // % rustc +stable --version
11 // rustc 1.26.0 (a77568041 2018-05-07)
12 // % rustc +beta --version
13 // rustc 1.27.0-beta.1 (03fb2f447 2018-05-09)
14 // % rustc +nightly --version
15 // rustc 1.27.0-nightly (acd3871ba 2018-05-10)
version_is_nightly(version: &str) -> bool16 fn version_is_nightly(version: &str) -> bool {
17 version.contains("nightly")
18 }
19
cfg_rust_version()20 fn cfg_rust_version() {
21 let rustc = env::var("RUSTC").expect("RUSTC unset");
22
23 let mut child = process::Command::new(rustc)
24 .args(&["--version"])
25 .stdin(process::Stdio::null())
26 .stdout(process::Stdio::piped())
27 .spawn()
28 .expect("spawn rustc");
29
30 let mut rustc_version = String::new();
31
32 child
33 .stdout
34 .as_mut()
35 .expect("stdout")
36 .read_to_string(&mut rustc_version)
37 .expect("read_to_string");
38 assert!(child.wait().expect("wait").success());
39
40 if version_is_nightly(&rustc_version) {
41 println!("cargo:rustc-cfg=rustc_nightly");
42 }
43 }
44
cfg_serde()45 fn cfg_serde() {
46 match env::var("CARGO_FEATURE_WITH_SERDE") {
47 Ok(_) => {
48 println!("cargo:rustc-cfg=serde");
49 }
50 Err(VarError::NotUnicode(..)) => panic!(),
51 Err(VarError::NotPresent) => {}
52 }
53 }
54
out_dir() -> PathBuf55 fn out_dir() -> PathBuf {
56 PathBuf::from(env::var("OUT_DIR").expect("OUT_DIR"))
57 }
58
version() -> String59 fn version() -> String {
60 env::var("CARGO_PKG_VERSION").expect("CARGO_PKG_VERSION")
61 }
62
write_version()63 fn write_version() {
64 let version = version();
65 let version_ident = format!(
66 "VERSION_{}",
67 version.replace(".", "_").replace("-", "_").to_uppercase()
68 );
69 let mut file = File::create(Path::join(&out_dir(), "version.rs")).expect("open");
70 writeln!(file, "/// protobuf crate version").unwrap();
71 writeln!(file, "pub const VERSION: &'static str = \"{}\";", version).unwrap();
72 writeln!(file, "/// This symbol is used by codegen").unwrap();
73 writeln!(file, "#[doc(hidden)]").unwrap();
74 writeln!(
75 file,
76 "pub const VERSION_IDENT: &'static str = \"{}\";",
77 version_ident
78 )
79 .unwrap();
80 writeln!(
81 file,
82 "/// This symbol can be referenced to assert that proper version of crate is used"
83 )
84 .unwrap();
85 writeln!(file, "pub const {}: () = ();", version_ident).unwrap();
86 file.flush().unwrap();
87 }
88
main()89 fn main() {
90 cfg_rust_version();
91 cfg_serde();
92 write_version();
93 }
94