cleanup: Declare more padding fields as private Padding's

We have more fields that are padding areas that are currently marked as
public and not marked as Padding, which is causing the generated Hash
and PartialEq implementations to take care of them wrongly.

Author: 3v1n0

libc-test/build.rs

@@ -4597,9 +4597,6 @@ fn test_linux(target: &str) {
     cfg.skip_struct_field(move |struct_, field| {
         let struct_ = struct_.ident();
         let field = field.ident();
-        // this is actually a union on linux, so we can't represent it well and
-        // just insert some padding.
-        (struct_ == "siginfo_t" && field == "_pad") ||
         // musl names this __dummy1 but it's still there
         (musl && struct_ == "glob_t" && field == "gl_flags") ||
         // musl seems to define this as an *anonymous* bitfield
@@ -4630,7 +4627,7 @@ fn test_linux(target: &str) {
             && ((x86_64 || i686 || arm || riscv64) && gnu || x86_64_gnux32)
         ) ||
         // the `u` field is in fact an anonymous union
-        (gnu && struct_ == "ptrace_syscall_info" && (field == "u" || field == "pad")) ||
+        (gnu && struct_ == "ptrace_syscall_info" && (field == "u")) ||
         // the vregs field is a `__uint128_t` C's type.
         (struct_ == "user_fpsimd_struct" && field == "vregs") ||
         // Linux >= 5.11 tweaked the `svm_zero` field of the `sockaddr_vm` struct.

src/fuchsia/mod.rs

@@ -820,7 +820,7 @@ s! {
 
     pub struct cmsghdr {
         pub cmsg_len: crate::socklen_t,
-        pub __pad1: c_int,
+        __pad1: Padding<c_int>,
         pub cmsg_level: c_int,
         pub cmsg_type: c_int,
     }
@@ -833,7 +833,7 @@ s! {
         pub si_signo: c_int,
         pub si_errno: c_int,
         pub si_code: c_int,
-        pub _pad: [c_int; 29],
+        _pad: Padding<[c_int; 29]>,
         _align: [usize; 0],
     }
 
@@ -886,7 +886,7 @@ s! {
         pub totalswap: c_ulong,
         pub freeswap: c_ulong,
         pub procs: c_ushort,
-        pub pad: c_ushort,
+        pad: Padding<c_ushort>,
         pub totalhigh: c_ulong,
         pub freehigh: c_ulong,
         pub mem_unit: c_uint,
@@ -970,7 +970,7 @@ s! {
         pub sigev_notify: c_int,
         pub sigev_notify_function: fn(crate::sigval),
         pub sigev_notify_attributes: *mut pthread_attr_t,
-        pub __pad: [c_char; 56 - 3 * 8],
+        __pad: Padding<[c_char; 56 - 3 * 8]>,
     }
 
     #[cfg_attr(

src/new/apple/xnu/mach/arm/_structs.rs

@@ -2,7 +2,6 @@
 //!
 //! <https://github.com/apple-oss-distributions/xnu/blob/main/osfmk/mach/arm/_structs.h>
 
-#[cfg(target_arch = "arm")]
 use crate::prelude::*;
 
 s! {
@@ -19,7 +18,7 @@ s! {
         pub __sp: u64,
         pub __pc: u64,
         pub __cpsr: u32,
-        pub __pad: u32,
+        __pad: Padding<u32>,
     }
 
     #[cfg(target_arch = "aarch64")]

src/new/glibc/sysdeps/unix/linux/net/route.rs

@@ -7,20 +7,20 @@ use crate::prelude::*;
 
 s! {
     pub struct rtentry {
-        pub rt_pad1: c_ulong,
+        rt_pad1: Padding<c_ulong>,
         pub rt_dst: crate::sockaddr,
         pub rt_gateway: crate::sockaddr,
         pub rt_genmask: crate::sockaddr,
         pub rt_flags: c_ushort,
-        pub rt_pad2: c_short,
-        pub rt_pad3: c_ulong,
+        rt_pad2: Padding<c_short>,
+        rt_pad3: Padding<c_ulong>,
         pub rt_tos: c_uchar,
         pub rt_class: c_uchar,
         // FIXME(1.0): private padding fields
         #[cfg(target_pointer_width = "64")]
-        pub rt_pad4: [c_short; 3usize],
+        rt_pad4: Padding<[c_short; 3usize]>,
         #[cfg(not(target_pointer_width = "64"))]
-        pub rt_pad4: c_short,
+        rt_pad4: Padding<c_short>,
         pub rt_metric: c_short,
         pub rt_dev: *mut c_char,
         pub rt_mtu: c_ulong,

src/new/musl/sys/socket.rs

@@ -25,10 +25,10 @@ s! {
 
     pub struct cmsghdr {
         #[cfg(all(target_pointer_width = "64", target_endian = "big"))]
-        pub __pad1: c_int,
+        __pad1: Padding<c_int>,
         pub cmsg_len: crate::socklen_t,
         #[cfg(all(target_pointer_width = "64", target_endian = "little"))]
-        pub __pad1: c_int,
+        __pad1: Padding<c_int>,
         pub cmsg_level: c_int,
         pub cmsg_type: c_int,
     }

src/unix/aix/mod.rs

@@ -375,7 +375,7 @@ s! {
         pub ss_sp: *mut c_void,
         pub ss_size: size_t,
         pub ss_flags: c_int,
-        pub __pad: [c_int; 4],
+        __pad: Padding<[c_int; 4]>,
     }
 
     pub struct posix_spawnattr_t {
@@ -422,7 +422,7 @@ s! {
         pub ut_time: time64_t,
         pub ut_exit: exit_status,
         pub ut_host: [c_char; 256],
-        pub __dbl_word_pad: c_int,
+        __dbl_word_pad: Padding<c_int>,
         pub __reservedA: [c_int; 2],
         pub __reservedV: [c_int; 6],
     }

src/unix/aix/powerpc64.rs

@@ -127,10 +127,10 @@ s! {
 
     pub struct __vmx_context_t {
         pub __vr: [crate::__vmxreg_t; 32],
-        pub __pad1: [c_uint; 3],
+        __pad1: Padding<[c_uint; 3]>,
         pub __vscr: c_uint,
         pub __vrsave: c_uint,
-        pub __pad2: [c_uint; 3],
+        __pad2: Padding<[c_uint; 3]>,
     }
 
     pub struct __vsx_context_t {
@@ -158,7 +158,7 @@ s! {
         pub tmcontext: c_char,
         pub tmstate: c_char,
         pub prevowner: c_char,
-        pub pad: [c_char; 5],
+        pad: Padding<[c_char; 5]>,
     }
 
     pub struct __context64 {
@@ -176,7 +176,7 @@ s! {
         pub fpeu: c_char,
         pub fpinfo: c_char,
         pub fpscr24_31: c_char,
-        pub pad: [c_char; 1],
+        pad: Padding<[c_char; 1]>,
         pub excp_type: c_int,
     }
 
@@ -204,7 +204,7 @@ s! {
         pub uc_stack: crate::stack_t,
         pub __extctx: *mut crate::__extctx_t,
         pub __extctx_magic: c_int,
-        pub __pad: [c_int; 1],
+        __pad: Padding<[c_int; 1]>,
     }
 
     pub struct utmpx {
@@ -215,7 +215,7 @@ s! {
         pub ut_type: c_short,
         pub ut_tv: crate::timeval,
         pub ut_host: [c_char; 256],
-        pub __dbl_word_pad: c_int,
+        __dbl_word_pad: Padding<c_int>,
         pub __reservedA: [c_int; 2],
         pub __reservedV: [c_int; 6],
     }
@@ -256,7 +256,7 @@ s! {
         pub si_band: c_long,
         pub si_value: crate::sigval,
         pub __si_flags: c_int,
-        pub __pad: [c_int; 3],
+        __pad: Padding<[c_int; 3]>,
     }
 
     pub struct pollfd_ext {

src/unix/bsd/apple/mod.rs

@@ -845,7 +845,7 @@ s! {
     pub struct vnode_info {
         pub vi_stat: vinfo_stat,
         pub vi_type: c_int,
-        pub vi_pad: c_int,
+        vi_pad: Padding<c_int>,
         pub vi_fsid: crate::fsid_t,
     }
 
@@ -1234,10 +1234,10 @@ s! {
         pub sem_base: i32,
         pub sem_nsems: c_ushort,
         pub sem_otime: crate::time_t,
-        pub sem_pad1: i32,
+        sem_pad1: Padding<i32>,
         pub sem_ctime: crate::time_t,
-        pub sem_pad2: i32,
-        pub sem_pad3: [i32; 4],
+        sem_pad2: Padding<i32>,
+        sem_pad3: Padding<[i32; 4]>,
     }
 
     #[repr(packed(4))]

src/unix/bsd/freebsdlike/freebsd/aarch64.rs

@@ -13,22 +13,22 @@ s! {
         pub gp_sp: crate::register_t,
         pub gp_elr: crate::register_t,
         pub gp_spsr: u32,
-        pub gp_pad: c_int,
+        gp_pad: Padding<c_int>,
     }
 
     pub struct fpregs {
         pub fp_q: u128,
         pub fp_sr: u32,
         pub fp_cr: u32,
         pub fp_flags: c_int,
-        pub fp_pad: c_int,
+        fp_pad: Padding<c_int>,
     }
 
     pub struct mcontext_t {
         pub mc_gpregs: gpregs,
         pub mc_fpregs: fpregs,
         pub mc_flags: c_int,
-        pub mc_pad: c_int,
+        mc_pad: Padding<c_int>,
         pub mc_spare: [u64; 8],
     }
 }

src/unix/bsd/freebsdlike/freebsd/mod.rs

@@ -537,7 +537,7 @@ s! {
         pub t_pw: i16,
         pub t_sl: i16,
         pub t_sw: i16,
-        pub t_pad: [u16; 3],
+        t_pad: Padding<[u16; 3]>,
     }
 
     pub struct sockstat {
@@ -1040,11 +1040,11 @@ s! {
         #[cfg(any(freebsd15, freebsd14, freebsd13))]
         pub tcpi_dupacks: u32,
         #[cfg(any(freebsd14, freebsd13))]
-        pub __tcpi_pad: [u32; 10],
+        __tcpi_pad: Padding<[u32; 10]>,
         #[cfg(freebsd15)]
-        pub __tcpi_pad: [u32; 14],
+        __tcpi_pad: Padding<[u32; 14]>,
         #[cfg(not(any(freebsd15, freebsd14, freebsd13)))]
-        pub __tcpi_pad: [u32; 26],
+        __tcpi_pad: Padding<[u32; 26]>,
     }
 
     pub struct _umtx_time {
@@ -1112,7 +1112,7 @@ s! {
         pub sinfo_assoc_id: crate::sctp_assoc_t,
         pub sinfo_keynumber: u16,
         pub sinfo_keynumber_valid: u16,
-        pub __reserve_pad: [u8; SCTP_ALIGN_RESV_PAD],
+        __reserve_pad: Padding<[u8; SCTP_ALIGN_RESV_PAD]>,
     }
 
     pub struct sctp_extrcvinfo {
@@ -1132,7 +1132,7 @@ s! {
         pub serinfo_next_ppid: u32,
         pub sinfo_keynumber: u16,
         pub sinfo_keynumber_valid: u16,
-        pub __reserve_pad: [u8; SCTP_ALIGN_RESV_PAD_SHORT],
+        __reserve_pad: Padding<[u8; SCTP_ALIGN_RESV_PAD_SHORT]>,
     }
 
     pub struct sctp_sndinfo {