1 use std::env;
2 use std::process::Command;
3 use std::str;
4
main()5 fn main() {
6 let (rustc_minor_ver, is_nightly) =
7 rustc_minor_nightly().expect("Failed to get rustc version");
8 let rustc_dep_of_std = env::var("CARGO_FEATURE_RUSTC_DEP_OF_STD").is_ok();
9 let align_cargo_feature = env::var("CARGO_FEATURE_ALIGN").is_ok();
10 let const_extern_fn_cargo_feature =
11 env::var("CARGO_FEATURE_CONST_EXTERN_FN").is_ok();
12 let libc_ci = env::var("LIBC_CI").is_ok();
13
14 if env::var("CARGO_FEATURE_USE_STD").is_ok() {
15 println!(
16 "cargo:warning=\"libc's use_std cargo feature is deprecated since libc 0.2.55; \
17 please consider using the `std` cargo feature instead\""
18 );
19 }
20
21 // The ABI of libc used by libstd is backward compatible with FreeBSD 10.
22 // The ABI of libc from crates.io is backward compatible with FreeBSD 11.
23 //
24 // On CI, we detect the actual FreeBSD version and match its ABI exactly,
25 // running tests to ensure that the ABI is correct.
26 match which_freebsd() {
27 Some(10) if libc_ci || rustc_dep_of_std => {
28 println!("cargo:rustc-cfg=freebsd10")
29 }
30 Some(11) if libc_ci => println!("cargo:rustc-cfg=freebsd11"),
31 Some(12) if libc_ci => println!("cargo:rustc-cfg=freebsd12"),
32 Some(13) if libc_ci => println!("cargo:rustc-cfg=freebsd13"),
33 Some(_) | None => println!("cargo:rustc-cfg=freebsd11"),
34 }
35
36 // On CI: deny all warnings
37 if libc_ci {
38 println!("cargo:rustc-cfg=libc_deny_warnings");
39 }
40
41 // Rust >= 1.15 supports private module use:
42 if rustc_minor_ver >= 15 || rustc_dep_of_std {
43 println!("cargo:rustc-cfg=libc_priv_mod_use");
44 }
45
46 // Rust >= 1.19 supports unions:
47 if rustc_minor_ver >= 19 || rustc_dep_of_std {
48 println!("cargo:rustc-cfg=libc_union");
49 }
50
51 // Rust >= 1.24 supports const mem::size_of:
52 if rustc_minor_ver >= 24 || rustc_dep_of_std {
53 println!("cargo:rustc-cfg=libc_const_size_of");
54 }
55
56 // Rust >= 1.25 supports repr(align):
57 if rustc_minor_ver >= 25 || rustc_dep_of_std || align_cargo_feature {
58 println!("cargo:rustc-cfg=libc_align");
59 }
60
61 // Rust >= 1.30 supports `core::ffi::c_void`, so libc can just re-export it.
62 // Otherwise, it defines an incompatible type to retaining
63 // backwards-compatibility.
64 if rustc_minor_ver >= 30 || rustc_dep_of_std {
65 println!("cargo:rustc-cfg=libc_core_cvoid");
66 }
67
68 // Rust >= 1.33 supports repr(packed(N))
69 if rustc_minor_ver >= 33 || rustc_dep_of_std {
70 println!("cargo:rustc-cfg=libc_packedN");
71 }
72
73 // #[thread_local] is currently unstable
74 if rustc_dep_of_std {
75 println!("cargo:rustc-cfg=libc_thread_local");
76 }
77
78 if const_extern_fn_cargo_feature {
79 if !is_nightly || rustc_minor_ver < 40 {
80 panic!("const-extern-fn requires a nightly compiler >= 1.40")
81 }
82 println!("cargo:rustc-cfg=libc_const_extern_fn");
83 }
84 }
85
rustc_minor_nightly() -> Option<(u32, bool)>86 fn rustc_minor_nightly() -> Option<(u32, bool)> {
87 macro_rules! otry {
88 ($e:expr) => {
89 match $e {
90 Some(e) => e,
91 None => return None,
92 }
93 };
94 }
95
96 let rustc = otry!(env::var_os("RUSTC"));
97 let output = otry!(Command::new(rustc).arg("--version").output().ok());
98 let version = otry!(str::from_utf8(&output.stdout).ok());
99 let mut pieces = version.split('.');
100
101 if pieces.next() != Some("rustc 1") {
102 return None;
103 }
104
105 let minor = pieces.next();
106
107 // If `rustc` was built from a tarball, its version string
108 // will have neither a git hash nor a commit date
109 // (e.g. "rustc 1.39.0"). Treat this case as non-nightly,
110 // since a nightly build should either come from CI
111 // or a git checkout
112 let nightly_raw = otry!(pieces.next()).split('-').nth(1);
113 let nightly = nightly_raw
114 .map(|raw| raw.starts_with("dev") || raw.starts_with("nightly"))
115 .unwrap_or(false);
116 let minor = otry!(otry!(minor).parse().ok());
117
118 Some((minor, nightly))
119 }
120
which_freebsd() -> Option<i32>121 fn which_freebsd() -> Option<i32> {
122 let output = std::process::Command::new("freebsd-version").output().ok();
123 if output.is_none() {
124 return None;
125 }
126 let output = output.unwrap();
127 if !output.status.success() {
128 return None;
129 }
130
131 let stdout = String::from_utf8(output.stdout).ok();
132 if stdout.is_none() {
133 return None;
134 }
135 let stdout = stdout.unwrap();
136
137 match &stdout {
138 s if s.starts_with("10") => Some(10),
139 s if s.starts_with("11") => Some(11),
140 s if s.starts_with("12") => Some(12),
141 s if s.starts_with("13") => Some(13),
142 _ => None,
143 }
144 }
145