Auto merge of #2113 - joshtriplett:ci-kernel, r=JohnTitor

CI: Consolidate and blanket-ignore kernel definitions on non-glibc

Skip definitions from the kernel on non-glibc Linux targets.
They're libc-independent, so we only need to check them on one
libc. We don't want to break CI if musl or another libc doesn't
have the definitions yet. (We do still want to check them on
every glibc target, though, as some of them can vary by
architecture.)

Author: bors

libc-test/build.rs

@@ -2561,6 +2561,39 @@ fn test_linux(target: &str) {
     });
 
     cfg.skip_const(move |name| {
+        if !gnu {
+            // Skip definitions from the kernel on non-glibc Linux targets.
+            // They're libc-independent, so we only need to check them on one
+            // libc. We don't want to break CI if musl or another libc doesn't
+            // have the definitions yet. (We do still want to check them on
+            // every glibc target, though, as some of them can vary by
+            // architecture.)
+            //
+            // This is not an exhaustive list of kernel constants, just a list
+            // of prefixes of all those that have appeared here or that get
+            // updated regularly and seem likely to cause breakage.
+            if name.starts_with("AF_")
+                || name.starts_with("ARPHRD_")
+                || name.starts_with("EPOLL")
+                || name.starts_with("F_")
+                || name.starts_with("FALLOC_FL_")
+                || name.starts_with("IFLA_")
+                || name.starts_with("MS_")
+                || name.starts_with("MSG_")
+                || name.starts_with("P_")
+                || name.starts_with("PF_")
+                || name.starts_with("RLIMIT_")
+                || name.starts_with("SOL_")
+                || name.starts_with("STATX_")
+                || name.starts_with("SW_")
+                || name.starts_with("SYS_")
+                || name.starts_with("TCP_")
+                || name.starts_with("UINPUT_")
+                || name.starts_with("VMADDR_")
+            {
+                return true;
+            }
+        }
         match name {
             // These constants are not available if gnu headers have been included
             // and can therefore not be tested here
@@ -2580,25 +2613,9 @@ fn test_linux(target: &str) {
             | "F_SEAL_GROW"
             | "F_SEAL_WRITE" => true,
 
-            // The musl-sanitized kernel headers used in CI
-            // target the Linux kernel 4.4 and do not contain the
-            // following constants:
-            //
-            // Requires Linux kernel 4.9
-            | "FALLOC_FL_UNSHARE_RANGE"
-            //
-            // Require Linux kernel 5.x:
-            | "MSG_COPY"
-               if musl  => true,
             // Require Linux kernel 5.1:
             "F_SEAL_FUTURE_WRITE" => true,
 
-            // The musl version 1.1.24 used in CI does not
-            // contain these glibc constants yet:
-            | "RLIMIT_RTTIME" // should be in `resource.h`
-            | "TCP_COOKIE_TRANSACTIONS"  // should be in the `netinet/tcp.h` header
-                if musl => true,
-
             // FIXME: deprecated: not available in any header
             // See: https://github.com/rust-lang/libc/issues/1356
             "ENOATTR" => true,
@@ -2629,33 +2646,13 @@ fn test_linux(target: &str) {
             | "IPPROTO_MAX"
             | "IPPROTO_MPTCP" => true,
 
-            // Defined in kernel headers but musl removes it; need musl 1.2 for definition in musl
-            // headers.
-            "P_PIDFD" => true,
-
             // FIXME: Not currently available in headers
+            "P_PIDFD" if mips => true,
             "SYS_pidfd_open" if mips => true,
 
             // FIXME: Not currently available in headers on MIPS
             // Not yet implemented on sparc64
-            // FIXME: available in musl headers since musl 1.2.0 
-            "SYS_clone3" if mips | sparc64 | musl => true,
-
-            // Missing from musl's kernel headers
-            | "IFLA_GSO_MAX_SEGS"
-            | "IFLA_GSO_MAX_SIZE"
-            | "IFLA_PAD"
-            | "IFLA_XDP"
-            | "IFLA_EVENT"
-            | "IFLA_NEW_NETNSID"
-            | "IFLA_IF_NETNSID"
-            | "IFLA_TARGET_NETNSID"
-            | "IFLA_CARRIER_UP_COUNT"
-            | "IFLA_CARRIER_DOWN_COUNT"
-            | "IFLA_NEW_IFINDEX"
-            | "IFLA_MIN_MTU"
-            | "IFLA_MAX_MTU"
-                if musl => true,
+            "SYS_clone3" if mips | sparc64 => true,
 
             // Requires more recent kernel headers:
             | "IFLA_PROP_LIST"
@@ -2668,23 +2665,14 @@ fn test_linux(target: &str) {
             | "CAN_RAW_FILTER_MAX"
             | "CAN_NPROTO" => true,
 
-            "MS_RMT_MASK" if uclibc => true, // updated in glibc 2.22 and musl 1.1.13
-
-            // These are not defined in uclibc but will be passed through to the kernel
-            // so they will be supported if the kernel supports them.  Otherwise the
-            // kernel will return runtime errors.  Since they're required for tokio 
-            // support, we except them from the tests here.
-            // See https://github.com/rust-lang/libc/pull/2019#issuecomment-754351482
-            "EPOLLEXCLUSIVE" | "EPOLLWAKEUP" if uclibc => true,
-
             // FIXME: Requires recent kernel headers (5.8):
             "STATX_MNT_ID" => true,
 
             // FIXME: requires more recent kernel headers on CI
             | "UINPUT_VERSION"
             | "SW_MAX"
             | "SW_CNT"
-                if musl || mips || ppc64 || riscv64 || sparc64 => true,
+                if mips || ppc64 || riscv64 || sparc64 => true,
 
             _ => false,
         }