Require rust >= 1.40 and drop libc_non_exhaustive conditional

Author: joshtriplett

Cargo.toml

@@ -14,7 +14,7 @@ exclude = ["/ci/*", "/.github/*", "/.cirrus.yml", "/triagebot.toml"]
 description = """
 Raw FFI bindings to platform libraries like libc.
 """
-rust-version = "1.37"
+rust-version = "1.40"
 
 [package.metadata.docs.rs]
 features = ["const-extern-fn", "extra_traits"]

build.rs

@@ -42,11 +42,6 @@ fn main() {
         println!("cargo:rustc-cfg=libc_deny_warnings");
     }
 
-    // Rust >= 1.40 supports #[non_exhaustive].
-    if rustc_minor_ver >= 40 || rustc_dep_of_std {
-        println!("cargo:rustc-cfg=libc_non_exhaustive");
-    }
-
     if rustc_minor_ver >= 51 || rustc_dep_of_std {
         println!("cargo:rustc-cfg=libc_ptr_addr_of");
     }

src/unix/linux_like/linux/mod.rs

@@ -650,6 +650,14 @@ s! {
         pub fd: ::c_int,
         pub pid: ::c_int,
     }
+
+    // linux/openat2.h
+    #[non_exhaustive]
+    pub struct open_how {
+        pub flags: ::__u64,
+        pub mode: ::__u64,
+        pub resolve: ::__u64,
+    }
 }
 
 s_no_extra_traits! {
@@ -4245,10 +4253,3 @@ cfg_if! {
 
 mod arch;
 pub use self::arch::*;
-
-cfg_if! {
-    if #[cfg(libc_non_exhaustive)] {
-        mod non_exhaustive;
-        pub use self::non_exhaustive::*;
-    }
-}