1 // SPDX-License-Identifier: Apache-2.0
2 
3 //! Finds `libclang` static or shared libraries and links to them.
4 //!
5 //! # Environment Variables
6 //!
7 //! This build script can make use of several environment variables to help it
8 //! find the required static or shared libraries.
9 //!
10 //! * `LLVM_CONFIG_PATH` - provides a path to an `llvm-config` executable
11 //! * `LIBCLANG_PATH` - provides a path to a directory containing a `libclang`
12 //!    shared library or a path to a specific `libclang` shared library
13 //! * `LIBCLANG_STATIC_PATH` - provides a path to a directory containing LLVM
14 //!    and Clang static libraries
15 
16 #![allow(unused_attributes)]
17 
18 extern crate glob;
19 
20 use std::path::Path;
21 
22 #[macro_use]
23 #[path = "build/macros.rs"]
24 pub mod macros;
25 
26 #[path = "build/common.rs"]
27 pub mod common;
28 #[path = "build/dynamic.rs"]
29 pub mod dynamic;
30 #[path = "build/static.rs"]
31 pub mod r#static;
32 
33 /// Copies a file.
34 #[cfg(feature = "runtime")]
copy(source: &str, destination: &Path)35 fn copy(source: &str, destination: &Path) {
36     use std::fs::File;
37     use std::io::{Read, Write};
38 
39     let mut string = String::new();
40     File::open(source)
41         .unwrap()
42         .read_to_string(&mut string)
43         .unwrap();
44     File::create(destination)
45         .unwrap()
46         .write_all(string.as_bytes())
47         .unwrap();
48 }
49 
50 /// Copies the code used to find and link to `libclang` shared libraries into
51 /// the build output directory so that it may be used when linking at runtime.
52 #[cfg(feature = "runtime")]
main()53 fn main() {
54     use std::env;
55 
56     if cfg!(feature = "static") {
57         panic!("`runtime` and `static` features can't be combined");
58     }
59 
60     let out = env::var("OUT_DIR").unwrap();
61     copy("build/macros.rs", &Path::new(&out).join("macros.rs"));
62     copy("build/common.rs", &Path::new(&out).join("common.rs"));
63     copy("build/dynamic.rs", &Path::new(&out).join("dynamic.rs"));
64 }
65 
66 /// Finds and links to the required libraries dynamically or statically.
67 #[cfg(not(feature = "runtime"))]
main()68 fn main() {
69     if cfg!(feature = "static") {
70         r#static::link();
71     } else {
72         dynamic::link();
73     }
74 
75     if let Some(output) = common::run_llvm_config(&["--includedir"]) {
76         let directory = Path::new(output.trim_end());
77         println!("cargo:include={}", directory.display());
78     }
79 }
80