From a433bcee1300bf3f68e56a6f85bd813006071724 Mon Sep 17 00:00:00 2001
From: kellda <59569234+kellda@users.noreply.github.com>
Date: Wed, 3 Feb 2021 22:16:47 +0000
Subject: [PATCH 1/4] Make `sigval` an union

---
 libc-test/build.rs | 82 ++--------------------------------------------
 src/fuchsia/mod.rs | 40 ++++++++++------------
 src/unix/mod.rs    | 28 +++++++++++++---
 3 files changed, 42 insertions(+), 108 deletions(-)

diff --git a/libc-test/build.rs b/libc-test/build.rs
index eb2a5dfe72c46..4622798104465 100644
--- a/libc-test/build.rs
+++ b/libc-test/build.rs
@@ -325,9 +325,6 @@ fn test_apple(target: &str) {
             return true;
         }
         match ty {
-            // FIXME: actually a union
-            "sigval" => true,
-
             // FIXME: The size is changed in recent macOSes.
             "malloc_zone_t" => true,
             // it is a moving target, changing through versions
@@ -423,14 +420,6 @@ fn test_apple(target: &str) {
         }
     });
 
-    cfg.skip_field_type(move |struct_, field| {
-        match (struct_, field) {
-            // FIXME: actually a union
-            ("sigevent", "sigev_value") => true,
-            _ => false,
-        }
-    });
-
     cfg.volatile_item(|i| {
         use ctest::VolatileItemKind::*;
         match i {
@@ -570,27 +559,6 @@ fn test_openbsd(target: &str) {
         "sys/param.h",
     }
 
-    cfg.skip_struct(move |ty| {
-        if ty.starts_with("__c_anonymous_") {
-            return true;
-        }
-        match ty {
-            // FIXME: actually a union
-            "sigval" => true,
-
-            _ => false,
-        }
-    });
-
-    cfg.skip_const(move |name| {
-        match name {
-            // Removed in OpenBSD 7.7 (unused since 1991)
-            "ATF_COM" | "ATF_PERM" | "ATF_PUBL" | "ATF_USETRAILERS" => true,
-
-            _ => false,
-        }
-    });
-
     cfg.skip_fn(move |name| {
         match name {
             // futex() has volatile arguments, but that doesn't exist in Rust.
@@ -985,8 +953,6 @@ fn test_solarish(target: &str) {
             return true;
         }
         match ty {
-            // union, not a struct
-            "sigval" => true,
             // a bunch of solaris-only fields
             "utmpx" if is_illumos => true,
             _ => false,
@@ -1006,8 +972,6 @@ fn test_solarish(target: &str) {
             "sigaction" if field == "sa_sigaction" => true,
             // Missing in illumos
             "sigevent" if field == "ss_sp" => true,
-            // Avoid sigval union issues
-            "sigevent" if field == "sigev_value" => true,
             // const issues
             "sigevent" if field == "sigev_notify_attributes" => true,
 
@@ -1230,8 +1194,6 @@ fn test_netbsd(target: &str) {
 
     cfg.skip_struct(move |ty| {
         match ty {
-            // This is actually a union, not a struct
-            "sigval" => true,
             // These are tested as part of the linux_fcntl tests since there are
             // header conflicts when including them with all the other structs.
             "termios2" => true,
@@ -1282,8 +1244,6 @@ fn test_netbsd(target: &str) {
         (struct_ == "ifaddrs" && field == "ifa_ifu") ||
         // sighandler_t type is super weird
         (struct_ == "sigaction" && field == "sa_sigaction") ||
-        // sigval is actually a union, but we pretend it's a struct
-        (struct_ == "sigevent" && field == "sigev_value") ||
         // aio_buf is "volatile void*" and Rust doesn't understand volatile
         (struct_ == "aiocb" && field == "aio_buf")
     });
@@ -1412,9 +1372,6 @@ fn test_dragonflybsd(target: &str) {
 
             t if t.ends_with("_t") => t.to_string(),
 
-            // sigval is a struct in Rust, but a union in C:
-            "sigval" => format!("union sigval"),
-
             // put `struct` in front of all structs:.
             t if is_struct => format!("struct {}", t),
 
@@ -1507,8 +1464,6 @@ fn test_dragonflybsd(target: &str) {
         (struct_ == "ifaddrs" && field == "ifa_ifu") ||
         // sighandler_t type is super weird
         (struct_ == "sigaction" && field == "sa_sigaction") ||
-        // sigval is actually a union, but we pretend it's a struct
-        (struct_ == "sigevent" && field == "sigev_value") ||
         // aio_buf is "volatile void*" and Rust doesn't understand volatile
         (struct_ == "aiocb" && field == "aio_buf")
     });
@@ -1799,9 +1754,6 @@ fn test_android(target: &str) {
 
             t if t.ends_with("_t") => t.to_string(),
 
-            // sigval is a struct in Rust, but a union in C:
-            "sigval" => format!("union sigval"),
-
             // put `struct` in front of all structs:.
             t if is_struct => format!("struct {}", t),
 
@@ -2096,8 +2048,6 @@ fn test_android(target: &str) {
     cfg.skip_field_type(move |struct_, field| {
         // This is a weird union, don't check the type.
         (struct_ == "ifaddrs" && field == "ifa_ifu") ||
-        // sigval is actually a union, but we pretend it's a struct
-        (struct_ == "sigevent" && field == "sigev_value") ||
         // this one is an anonymous union
         (struct_ == "ff_effect" && field == "u") ||
         // FIXME: `sa_sigaction` has type `sighandler_t` but that type is
@@ -2306,9 +2256,6 @@ fn test_freebsd(target: &str) {
 
             t if t.ends_with("_t") => t.to_string(),
 
-            // sigval is a struct in Rust, but a union in C:
-            "sigval" => format!("union sigval"),
-
             // put `struct` in front of all structs:.
             t if is_struct => format!("struct {}", t),
 
@@ -2928,9 +2875,6 @@ fn test_emscripten(target: &str) {
             return true;
         }
         match ty {
-            // This is actually a union, not a struct
-            "sigval" => true,
-
             // FIXME: Investigate why the test fails.
             // Skip for now to unblock CI.
             "pthread_condattr_t" => true,
@@ -3006,9 +2950,7 @@ fn test_emscripten(target: &str) {
         // This is a weird union, don't check the type.
         (struct_ == "ifaddrs" && field == "ifa_ifu") ||
         // sighandler_t type is super weird
-        (struct_ == "sigaction" && field == "sa_sigaction") ||
-        // sigval is actually a union, but we pretend it's a struct
-        (struct_ == "sigevent" && field == "sigev_value")
+        (struct_ == "sigaction" && field == "sa_sigaction")
     });
 
     cfg.skip_field(move |struct_, field| {
@@ -3204,9 +3146,6 @@ fn test_neutrino(target: &str) {
         match ty {
             "Elf64_Phdr" | "Elf32_Phdr" => true,
 
-            // FIXME(union): This is actually a union, not a struct
-            "sigval" => true,
-
             // union
             "_channel_connect_attr" => true,
 
@@ -3258,8 +3197,6 @@ fn test_neutrino(target: &str) {
     });
 
     cfg.skip_field_type(move |struct_, field| {
-        // sigval is actually a union, but we pretend it's a struct
-        struct_ == "sigevent" && field == "sigev_value" ||
         // Anonymous structures
         struct_ == "_idle_hook" && field == "time"
     });
@@ -3268,8 +3205,6 @@ fn test_neutrino(target: &str) {
         (struct_ == "__sched_param" && field == "reserved") ||
         (struct_ == "sched_param" && field == "reserved") ||
         (struct_ == "sigevent" && field == "__padding1") || // ensure alignment
-        (struct_ == "sigevent" && field == "__padding2") || // union
-        (struct_ == "sigevent" && field == "__sigev_un2") || // union
         // sighandler_t type is super weird
         (struct_ == "sigaction" && field == "sa_sigaction") ||
         // does not exist
@@ -3378,10 +3313,8 @@ fn test_vxworks(target: &str) {
 
     // FIXME(vxworks)
     cfg.skip_fn(move |name| match name {
-        // sigval
-        "sigqueue" | "_sigqueue"
         // sighandler_t
-        | "signal"
+        "signal"
         // not used in static linking by default
         | "dlerror" => true,
         _ => false,
@@ -3770,9 +3703,6 @@ fn test_linux(target: &str) {
             // which is absent in glibc, has to be defined.
             "__timeval" => true,
 
-            // FIXME(union): This is actually a union, not a struct
-            "sigval" => true,
-
             // This type is tested in the `linux_termios.rs` file since there
             // are header conflicts when including them with all the other
             // structs.
@@ -4374,8 +4304,6 @@ fn test_linux(target: &str) {
         (struct_ == "sigaction" && field == "sa_sigaction") ||
         // __timeval type is a patch which doesn't exist in glibc
         (struct_ == "utmpx" && field == "ut_tv") ||
-        // sigval is actually a union, but we pretend it's a struct
-        (struct_ == "sigevent" && field == "sigev_value") ||
         // this one is an anonymous union
         (struct_ == "ff_effect" && field == "u") ||
         // `__exit_status` type is a patch which is absent in musl
@@ -4847,8 +4775,6 @@ fn test_haiku(target: &str) {
             return true;
         }
         match ty {
-            // FIXME: actually a union
-            "sigval" => true,
             // FIXME: locale_t does not exist on Haiku
             "locale_t" => true,
             // FIXME: rusage has a different layout on Haiku
@@ -4955,10 +4881,8 @@ fn test_haiku(target: &str) {
             ("stat", "st_crtime_nsec") => true,
 
             // these are actually unions, but we cannot represent it well
-            ("siginfo_t", "sigval") => true,
             ("sem_t", "named_sem_id") => true,
             ("sigaction", "sa_sigaction") => true,
-            ("sigevent", "sigev_value") => true,
             ("fpu_state", "_fpreg") => true,
             ("cpu_topology_node_info", "data") => true,
             // these fields have a simplified data definition in libc
@@ -5009,8 +4933,6 @@ fn test_haiku(target: &str) {
                 ty.to_string()
             }
 
-            // is actually a union
-            "sigval" => format!("union sigval"),
             t if is_union => format!("union {}", t),
             t if t.ends_with("_t") => t.to_string(),
             t if is_struct => format!("struct {}", t),
diff --git a/src/fuchsia/mod.rs b/src/fuchsia/mod.rs
index f9a7ed929eaaf..441ba6e75419c 100644
--- a/src/fuchsia/mod.rs
+++ b/src/fuchsia/mod.rs
@@ -253,11 +253,6 @@ s! {
         pub l_linger: c_int,
     }
 
-    pub struct sigval {
-        // Actually a union of an int and a void*
-        pub sival_ptr: *mut c_void,
-    }
-
     // <sys/time.h>
     pub struct itimerval {
         pub it_interval: crate::timeval,
@@ -1054,6 +1049,11 @@ s_no_extra_traits! {
     pub struct pthread_cond_t {
         size: [u8; crate::__SIZEOF_PTHREAD_COND_T],
     }
+
+    pub union sigval {
+        pub sival_int: c_int,
+        pub sival_ptr: *mut c_void,
+    }
 }
 
 cfg_if! {
@@ -1360,17 +1360,6 @@ cfg_if! {
             }
         }
         impl Eq for sigevent {}
-        impl fmt::Debug for sigevent {
-            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-                f.debug_struct("sigevent")
-                    .field("sigev_value", &self.sigev_value)
-                    .field("sigev_signo", &self.sigev_signo)
-                    .field("sigev_notify", &self.sigev_notify)
-                    .field("sigev_notify_function", &self.sigev_notify_function)
-                    .field("sigev_notify_attributes", &self.sigev_notify_attributes)
-                    .finish()
-            }
-        }
         impl hash::Hash for sigevent {
             fn hash<H: hash::Hasher>(&self, state: &mut H) {
                 self.sigev_value.hash(state);
@@ -1425,18 +1414,23 @@ cfg_if! {
             }
         }
         impl Eq for pthread_rwlock_t {}
-        impl fmt::Debug for pthread_rwlock_t {
-            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-                f.debug_struct("pthread_rwlock_t")
-                    // FIXME: .field("size", &self.size)
-                    .finish()
-            }
-        }
         impl hash::Hash for pthread_rwlock_t {
             fn hash<H: hash::Hasher>(&self, state: &mut H) {
                 self.size.hash(state);
             }
         }
+
+        impl PartialEq for sigval {
+            fn eq(&self, other: &sigval) -> bool {
+                unimplemented!("traits")
+            }
+        }
+        impl Eq for sigval {}
+        impl hash::Hash for sigval {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                unimplemented!("traits")
+            }
+        }
     }
 }
 
diff --git a/src/unix/mod.rs b/src/unix/mod.rs
index 84298804c594f..0c069165da8ec 100644
--- a/src/unix/mod.rs
+++ b/src/unix/mod.rs
@@ -176,11 +176,6 @@ s! {
         pub l_linger: c_int,
     }
 
-    pub struct sigval {
-        // Actually a union of an int and a void*
-        pub sival_ptr: *mut c_void,
-    }
-
     // <sys/time.h>
     pub struct itimerval {
         pub it_interval: crate::timeval,
@@ -214,6 +209,29 @@ s! {
     }
 }
 
+s_no_extra_traits! {
+    pub union sigval {
+        pub sival_int: c_int,
+        pub sival_ptr: *mut c_void,
+    }
+}
+
+cfg_if! {
+    if #[cfg(feature = "extra_traits")] {
+        impl PartialEq for sigval {
+            fn eq(&self, other: &sigval) -> bool {
+                unimplemented!("traits")
+            }
+        }
+        impl Eq for sigval {}
+        impl hash::Hash for sigval {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                unimplemented!("traits")
+            }
+        }
+    }
+}
+
 pub const INT_MIN: c_int = -2147483648;
 pub const INT_MAX: c_int = 2147483647;
 

From 10ff5d453c9ffb8387566b0248c101fcabadda82 Mon Sep 17 00:00:00 2001
From: kellda <59569234+kellda@users.noreply.github.com>
Date: Thu, 4 Feb 2021 12:40:05 +0000
Subject: [PATCH 2/4] Make `ifaddrs.ifa_ifu` an union

---
 src/fuchsia/mod.rs         | 19 ++++++++++++++++++-
 src/unix/linux_like/mod.rs | 28 +++++++++++++++++++++++++++-
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/fuchsia/mod.rs b/src/fuchsia/mod.rs
index 441ba6e75419c..27ec248483d27 100644
--- a/src/fuchsia/mod.rs
+++ b/src/fuchsia/mod.rs
@@ -473,7 +473,7 @@ s! {
         pub ifa_flags: c_uint,
         pub ifa_addr: *mut crate::sockaddr,
         pub ifa_netmask: *mut crate::sockaddr,
-        pub ifa_ifu: *mut crate::sockaddr, // FIXME This should be a union
+        pub ifa_ifu: __c_anonymous_ifa_ifu,
         pub ifa_data: *mut c_void,
     }
 
@@ -1054,6 +1054,11 @@ s_no_extra_traits! {
         pub sival_int: c_int,
         pub sival_ptr: *mut c_void,
     }
+
+    pub union __c_anonymous_ifa_ifu {
+        ifu_broadaddr: *mut sockaddr,
+        ifu_dstaddr: *mut sockaddr,
+    }
 }
 
 cfg_if! {
@@ -1431,6 +1436,18 @@ cfg_if! {
                 unimplemented!("traits")
             }
         }
+
+        impl PartialEq for __c_anonymous_ifa_ifu {
+            fn eq(&self, other: &__c_anonymous_ifa_ifu) -> bool {
+                unimplemented!("traits")
+            }
+        }
+        impl Eq for __c_anonymous_ifa_ifu {}
+        impl hash::Hash for __c_anonymous_ifa_ifu {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                unimplemented!("traits")
+            }
+        }
     }
 }
 
diff --git a/src/unix/linux_like/mod.rs b/src/unix/linux_like/mod.rs
index 6678cb6d74870..c5c7c256a5dd9 100644
--- a/src/unix/linux_like/mod.rs
+++ b/src/unix/linux_like/mod.rs
@@ -166,7 +166,7 @@ s! {
         pub ifa_flags: c_uint,
         pub ifa_addr: *mut crate::sockaddr,
         pub ifa_netmask: *mut crate::sockaddr,
-        pub ifa_ifu: *mut crate::sockaddr, // FIXME(union) This should be a union
+        pub ifa_ifu: __c_anonymous_ifa_ifu,
         pub ifa_data: *mut c_void,
     }
 
@@ -303,6 +303,11 @@ s_no_extra_traits! {
         pub sigev_notify: c_int,
         pub _sigev_un: __c_anonymous_sigev_un,
     }
+
+    pub union __c_anonymous_ifa_ifu {
+        ifu_broadaddr: *mut sockaddr,
+        ifu_dstaddr: *mut sockaddr,
+    }
 }
 
 cfg_if! {
@@ -459,6 +464,27 @@ cfg_if! {
                     .finish()
             }
         }
+
+        impl hash::Hash for sigevent {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                self.sigev_value.hash(state);
+                self.sigev_signo.hash(state);
+                self.sigev_notify.hash(state);
+                self.sigev_notify_thread_id.hash(state);
+            }
+        }
+
+        impl PartialEq for __c_anonymous_ifa_ifu {
+            fn eq(&self, other: &__c_anonymous_ifa_ifu) -> bool {
+                unimplemented!("traits")
+            }
+        }
+        impl Eq for __c_anonymous_ifa_ifu {}
+        impl hash::Hash for __c_anonymous_ifa_ifu {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                unimplemented!("traits")
+            }
+        }
     }
 }
 

From 81e2b6c48e65ab842ce50bc4f6df0d29a3c09aa6 Mon Sep 17 00:00:00 2001
From: kellda <59569234+kellda@users.noreply.github.com>
Date: Thu, 4 Feb 2021 13:56:20 +0000
Subject: [PATCH 3/4] Implement `epoll_data` union

---
 libc-test/build.rs         | 12 ------------
 src/fuchsia/mod.rs         |  7 +++++++
 src/unix/linux_like/mod.rs | 35 ++++++++++++++++++++-------------
 src/unix/solarish/mod.rs   | 40 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 69 insertions(+), 25 deletions(-)

diff --git a/libc-test/build.rs b/libc-test/build.rs
index 4622798104465..96087fe1a082a 100644
--- a/libc-test/build.rs
+++ b/libc-test/build.rs
@@ -906,8 +906,6 @@ fn test_solarish(target: &str) {
 
     cfg.field_name(move |struct_, field| {
         match struct_ {
-            // rust struct uses raw u64, rather than union
-            "epoll_event" if field == "u64" => "data.u64".to_string(),
             // rust struct was committed with typo for Solaris
             "door_arg_t" if field == "dec_num" => "desc_num".to_string(),
             "stat" if field.ends_with("_nsec") => {
@@ -1176,7 +1174,6 @@ fn test_netbsd(target: &str) {
             s if s.ends_with("_nsec") && struct_.starts_with("stat") => {
                 s.replace("e_nsec", ".tv_nsec")
             }
-            "u64" if struct_ == "epoll_event" => "data.u64".to_string(),
             s => s.to_string(),
         }
     });
@@ -1386,7 +1383,6 @@ fn test_dragonflybsd(target: &str) {
             s if s.ends_with("_nsec") && struct_.starts_with("stat") => {
                 s.replace("e_nsec", ".tv_nsec")
             }
-            "u64" if struct_ == "epoll_event" => "data.u64".to_string(),
             // Field is named `type` in C but that is a Rust keyword,
             // so these fields are translated to `type_` in the bindings.
             "type_" if struct_ == "rtprio" => "type".to_string(),
@@ -1766,8 +1762,6 @@ fn test_android(target: &str) {
             // Our stat *_nsec fields normally don't actually exist but are part
             // of a timeval struct
             s if s.ends_with("_nsec") && struct_.starts_with("stat") => s.to_string(),
-            // FIXME: appears that `epoll_event.data` is an union
-            "u64" if struct_ == "epoll_event" => "data.u64".to_string(),
             // The following structs have a field called `type` in C,
             // but `type` is a Rust keyword, so these fields are translated
             // to `type_` in Rust.
@@ -2848,8 +2842,6 @@ fn test_emscripten(target: &str) {
             s if s.ends_with("_nsec") && struct_.starts_with("stat") => {
                 s.replace("e_nsec", ".tv_nsec")
             }
-            // Rust struct uses raw u64, rather than union
-            "u64" if struct_ == "epoll_event" => "data.u64".to_string(),
             s => s.to_string(),
         }
     });
@@ -3585,10 +3577,6 @@ fn test_linux(target: &str) {
             s if s.ends_with("_nsec") && struct_.starts_with("stat") => {
                 s.replace("e_nsec", ".tv_nsec")
             }
-            // FIXME(linux): epoll_event.data is actually a union in C, but in Rust
-            // it is only a u64 because we only expose one field
-            // http://man7.org/linux/man-pages/man2/epoll_wait.2.html
-            "u64" if struct_ == "epoll_event" => "data.u64".to_string(),
             // The following structs have a field called `type` in C,
             // but `type` is a Rust keyword, so these fields are translated
             // to `type_` in Rust.
diff --git a/src/fuchsia/mod.rs b/src/fuchsia/mod.rs
index 27ec248483d27..a87ae57dcb645 100644
--- a/src/fuchsia/mod.rs
+++ b/src/fuchsia/mod.rs
@@ -419,6 +419,13 @@ s! {
 
     pub struct epoll_event {
         pub events: u32,
+        pub data: epoll_data,
+    }
+
+    pub union epoll_data {
+        pub ptr: *mut c_void,
+        pub fd: c_int,
+        pub u32: u32,
         pub u64: u64,
     }
 
diff --git a/src/unix/linux_like/mod.rs b/src/unix/linux_like/mod.rs
index c5c7c256a5dd9..6f89f2c596f49 100644
--- a/src/unix/linux_like/mod.rs
+++ b/src/unix/linux_like/mod.rs
@@ -265,6 +265,13 @@ s_no_extra_traits! {
     )]
     pub struct epoll_event {
         pub events: u32,
+        pub data: epoll_data,
+    }
+
+    pub union epoll_data {
+        pub ptr: *mut c_void,
+        pub fd: c_int,
+        pub u32: u32,
         pub u64: u64,
     }
 
@@ -314,26 +321,28 @@ cfg_if! {
     if #[cfg(feature = "extra_traits")] {
         impl PartialEq for epoll_event {
             fn eq(&self, other: &epoll_event) -> bool {
-                self.events == other.events && self.u64 == other.u64
+                unimplemented!("traits")
             }
         }
         impl Eq for epoll_event {}
-        impl fmt::Debug for epoll_event {
-            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-                let events = self.events;
-                let u64 = self.u64;
-                f.debug_struct("epoll_event")
-                    .field("events", &events)
-                    .field("u64", &u64)
-                    .finish()
-            }
-        }
         impl hash::Hash for epoll_event {
             fn hash<H: hash::Hasher>(&self, state: &mut H) {
                 let events = self.events;
-                let u64 = self.u64;
+                let data = self.data;
                 events.hash(state);
-                u64.hash(state);
+                data.hash(state);
+            }
+        }
+
+        impl PartialEq for epoll_data {
+            fn eq(&self, other: &epoll_data) -> bool {
+                unimplemented!("traits")
+            }
+        }
+        impl Eq for epoll_data {}
+        impl hash::Hash for epoll_data {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                unimplemented!("traits")
             }
         }
 
diff --git a/src/unix/solarish/mod.rs b/src/unix/solarish/mod.rs
index 228ba04b84455..9a209363805cb 100644
--- a/src/unix/solarish/mod.rs
+++ b/src/unix/solarish/mod.rs
@@ -501,6 +501,22 @@ s! {
 }
 
 s_no_extra_traits! {
+    #[cfg_attr(any(
+        target_arch = "x86", target_arch = "x86_64"),
+        repr(packed(4))
+    )]
+    pub struct epoll_event {
+        pub events: u32,
+        pub data: epoll_data,
+    }
+
+    pub union epoll_data {
+        pub ptr: *mut c_void,
+        pub fd: c_int,
+        pub u32: u32,
+        pub u64: u64,
+    }
+
     pub struct sockaddr_un {
         pub sun_family: sa_family_t,
         pub sun_path: [c_char; 108],
@@ -573,6 +589,30 @@ s_no_extra_traits! {
 
 cfg_if! {
     if #[cfg(feature = "extra_traits")] {
+        impl PartialEq for epoll_event {
+            fn eq(&self, other: &epoll_event) -> bool {
+                unimplemented!("traits")
+            }
+        }
+        impl Eq for epoll_event {}
+        impl hash::Hash for epoll_event {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                unimplemented!("traits")
+            }
+        }
+
+        impl PartialEq for epoll_data {
+            fn eq(&self, other: &epoll_data) -> bool {
+                unimplemented!("traits")
+            }
+        }
+        impl Eq for epoll_data {}
+        impl hash::Hash for epoll_data {
+            fn hash<H: hash::Hasher>(&self, state: &mut H) {
+                unimplemented!("traits")
+            }
+        }
+
         impl PartialEq for sockaddr_un {
             fn eq(&self, other: &sockaddr_un) -> bool {
                 self.sun_family == other.sun_family

From 5ea0e7056557e364a2c4ad433aed17c906021cfc Mon Sep 17 00:00:00 2001
From: kellda <59569234+kellda@users.noreply.github.com>
Date: Thu, 4 Feb 2021 14:50:57 +0000
Subject: [PATCH 4/4] Make `fpreg_t` an union

---
 libc-test/build.rs                         |  2 --
 src/unix/linux_like/linux/gnu/b64/s390x.rs | 16 ++++------------
 2 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/libc-test/build.rs b/libc-test/build.rs
index 96087fe1a082a..56f5591ac5e56 100644
--- a/libc-test/build.rs
+++ b/libc-test/build.rs
@@ -4398,8 +4398,6 @@ fn test_linux(target: &str) {
     cfg.skip_roundtrip(move |s| match s {
         // FIXME:
         "mcontext_t" if s390x => true,
-        // FIXME: This is actually a union.
-        "fpreg_t" if s390x => true,
 
         // The test doesn't work on some env:
         "ipv6_mreq"
diff --git a/src/unix/linux_like/linux/gnu/b64/s390x.rs b/src/unix/linux_like/linux/gnu/b64/s390x.rs
index 7a48de58c967b..d8850e88b892f 100644
--- a/src/unix/linux_like/linux/gnu/b64/s390x.rs
+++ b/src/unix/linux_like/linux/gnu/b64/s390x.rs
@@ -212,10 +212,9 @@ s! {
 }
 
 s_no_extra_traits! {
-    // FIXME(union): This is actually a union.
-    pub struct fpreg_t {
+    pub union fpreg_t {
         pub d: c_double,
-        // f: c_float,
+        pub f: c_float,
     }
 }
 
@@ -223,22 +222,15 @@ cfg_if! {
     if #[cfg(feature = "extra_traits")] {
         impl PartialEq for fpreg_t {
             fn eq(&self, other: &fpreg_t) -> bool {
-                self.d == other.d
+                unimplemented!("traits")
             }
         }
 
         impl Eq for fpreg_t {}
 
-        impl fmt::Debug for fpreg_t {
-            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-                f.debug_struct("fpreg_t").field("d", &self.d).finish()
-            }
-        }
-
         impl hash::Hash for fpreg_t {
             fn hash<H: hash::Hasher>(&self, state: &mut H) {
-                let d: u64 = unsafe { mem::transmute(self.d) };
-                d.hash(state);
+                unimplemented!("traits")
             }
         }
     }