1 use std::env; 2 use std::process::Command; 3 use std::str; 4 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 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 } 120 121 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