diff --git a/lib/std/Thread.zig b/lib/std/Thread.zig
index 99e2feb4cf43..5036012fccad 100644
--- a/lib/std/Thread.zig
+++ b/lib/std/Thread.zig
@@ -695,7 +695,7 @@ const PosixThreadImpl = struct {
         defer assert(c.pthread_attr_destroy(&attr) == .SUCCESS);
 
         // Use the same set of parameters used by the libc-less impl.
-        const stack_size = @max(config.stack_size, c.PTHREAD_STACK_MIN);
+        const stack_size = @max(config.stack_size, 16 * 1024);
         assert(c.pthread_attr_setstacksize(&attr, stack_size) == .SUCCESS);
         assert(c.pthread_attr_setguardsize(&attr, std.mem.page_size) == .SUCCESS);
 
diff --git a/lib/std/c.zig b/lib/std/c.zig
index 149f3ab7e199..41075607c394 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -408,11 +408,6 @@ pub extern "c" fn setlogmask(maskpri: c_int) c_int;
 
 pub extern "c" fn if_nametoindex([*:0]const u8) c_int;
 
-pub extern "c" fn timer_create(clockid: c.clockid_t, sevp: *c.sigevent, timerid: *c.timer_t) c_int;
-pub extern "c" fn timer_delete(timerid: c.timer_t) c_int;
-pub extern "c" fn timer_settime(timerid: c.timer_t, flags: c_int, new_value: *const c.itimerspec, old_value: *c.itimerspec) c_int;
-pub extern "c" fn timer_gettime(timerid: c.timer_t, flags: c_int, curr_value: *c.itimerspec) c_int;
-
 pub const max_align_t = if (builtin.abi == .msvc)
     f64
 else if (builtin.target.isDarwin())
diff --git a/lib/std/c/darwin.zig b/lib/std/c/darwin.zig
index 0f60c2f841d4..9c1e1b1a2ffe 100644
--- a/lib/std/c/darwin.zig
+++ b/lib/std/c/darwin.zig
@@ -163,67 +163,13 @@ pub extern "c" fn _dyld_get_image_header(image_index: u32) ?*mach_header;
 pub extern "c" fn _dyld_get_image_vmaddr_slide(image_index: u32) usize;
 pub extern "c" fn _dyld_get_image_name(image_index: u32) [*:0]const u8;
 
-pub const COPYFILE = struct {
-    pub const ACL = 1 << 0;
-    pub const STAT = 1 << 1;
-    pub const XATTR = 1 << 2;
-    pub const DATA = 1 << 3;
-    pub const SECURITY = COPYFILE.STAT | COPYFILE.ACL;
-    pub const METADATA = COPYFILE.SECURITY | COPYFILE.XATTR;
-    pub const ALL = COPYFILE.METADATA | COPYFILE.DATA;
-    pub const RECURSIVE = 1 << 15;
-    pub const CHECK = 1 << 16;
-    pub const EXCL = 1 << 17;
-    pub const NOFOLLOW_SRC = 1 << 18;
-    pub const NOFOLLOW_DST = 1 << 19;
-    pub const MOVE = 1 << 20;
-    pub const UNLINK = 1 << 21;
-    pub const NOFOLLOW = COPYFILE.NOFOLLOW_SRC | NOFOLLOW_DST;
-    pub const PACK = 1 << 22;
-    pub const UNPACK = 1 << 23;
-    pub const CLONE = 1 << 24;
-    pub const CLONE_FORCE = 1 << 25;
-    pub const RUN_IN_PLACE = 1 << 26;
-    pub const DATA_SPARSE = 1 << 27;
-    pub const PRESERVE_DST_TRACKED = 1 << 28;
-    pub const VERBOSE = 1 << 30;
-    pub const RECURSE_ERROR = 0;
-    pub const RECURSE_FILE = 1;
-    pub const RECURSE_DIR = 2;
-    pub const RECURSE_DIR_CLEANUP = 3;
-    pub const COPY_DATA = 4;
-    pub const COPY_XATTR = 5;
-    pub const START = 1;
-    pub const FINISH = 2;
-    pub const ERR = 3;
-    pub const PROGRESS = 4;
-    pub const CONTINUE = 0;
-    pub const SKIP = 1;
-    pub const QUIT = 2;
-    pub const STATE_SRC_FD = 1;
-    pub const STATE_SRC_FILENAME = 2;
-    pub const STATE_DST_FD = 3;
-    pub const STATE_DST_FILENAME = 4;
-    pub const STATE_QUARANTINE = 5;
-    pub const STATE_STATUS_CB = 6;
-    pub const STATE_STATUS_CTX = 7;
-    pub const STATE_COPIED = 8;
-    pub const STATE_XATTRNAME = 9;
-    pub const STATE_WAS_CLONED = 10;
-    pub const STATE_SRC_BSIZE = 11;
-    pub const STATE_DST_BSIZE = 12;
-    pub const STATE_BSIZE = 13;
-    pub const DISABLE_VAR: [*]u8 = "COPYFILE_DISABLE";
-};
+pub const COPYFILE_ACL = 1 << 0;
+pub const COPYFILE_STAT = 1 << 1;
+pub const COPYFILE_XATTR = 1 << 2;
+pub const COPYFILE_DATA = 1 << 3;
 
 pub const copyfile_state_t = *opaque {};
-pub const copyfile_flags_t = u32;
-pub extern "c" fn fcopyfile(from: fd_t, to: fd_t, state: ?copyfile_state_t, flags: copyfile_flags_t) c_int;
-pub extern "c" fn copyfile(from: [*:0]u8, to: [*:0]u8, state: ?copyfile_state_t, flags: copyfile_flags_t) c_int;
-pub extern "c" fn copyfile_state_alloc() copyfile_state_t;
-pub extern "c" fn copyfile_state_free(state: copyfile_state_t) void;
-pub extern "c" fn copyfile_state_get(s: copyfile_state_t, flag: u32, dst: ?*anyopaque) c_int;
-pub extern "c" fn copyfile_state_set(s: copyfile_state_t, flag: u32, dst: ?*const anyopaque) c_int;
+pub extern "c" fn fcopyfile(from: fd_t, to: fd_t, state: ?copyfile_state_t, flags: u32) c_int;
 
 pub extern "c" fn @"realpath$DARWIN_EXTSN"(noalias file_name: [*:0]const u8, noalias resolved_name: [*]u8) ?[*:0]u8;
 pub const realpath = @"realpath$DARWIN_EXTSN";
@@ -489,10 +435,6 @@ pub const VM_REGION_BASIC_INFO_COUNT: mach_msg_type_number_t = @sizeOf(vm_region
 pub const VM_REGION_EXTENDED_INFO_COUNT: mach_msg_type_number_t = @sizeOf(vm_region_extended_info) / @sizeOf(natural_t);
 pub const VM_REGION_TOP_INFO_COUNT: mach_msg_type_number_t = @sizeOf(vm_region_top_info) / @sizeOf(natural_t);
 
-pub fn VM_MAKE_TAG(tag: u8) u32 {
-    return @as(u32, tag) << 24;
-}
-
 pub const vm_region_basic_info_64 = extern struct {
     protection: vm_prot_t,
     max_protection: vm_prot_t,
@@ -907,21 +849,6 @@ pub const EAI = enum(c_int) {
 
 pub const EAI_MAX = 15;
 
-pub const qos_class_t = enum(c_uint) {
-    /// highest priority QOS class for critical tasks
-    QOS_CLASS_USER_INTERACTIVE = 0x21,
-    /// slightly more moderate priority QOS class
-    QOS_CLASS_USER_INITIATED = 0x19,
-    /// default QOS class when none is set
-    QOS_CLASS_DEFAULT = 0x15,
-    /// more energy efficient QOS class than default
-    QOS_CLASS_UTILITY = 0x11,
-    /// QOS class more appropriate for background tasks
-    QOS_CLASS_BACKGROUND = 0x09,
-    /// QOS class as a return value
-    QOS_CLASS_UNSPECIFIED = 0x00,
-};
-
 pub const pthread_mutex_t = extern struct {
     __sig: c_long = 0x32AAABA7,
     __opaque: [__PTHREAD_MUTEX_SIZE__]u8 = [_]u8{0} ** __PTHREAD_MUTEX_SIZE__,
@@ -946,40 +873,8 @@ pub const pthread_attr_t = extern struct {
 pub extern "c" fn pthread_threadid_np(thread: ?std.c.pthread_t, thread_id: *u64) c_int;
 pub extern "c" fn pthread_setname_np(name: [*:0]const u8) E;
 pub extern "c" fn pthread_getname_np(thread: std.c.pthread_t, name: [*:0]u8, len: usize) E;
-pub extern "c" fn pthread_attr_set_qos_class_np(attr: *pthread_attr_t, qos_class: qos_class_t, relative_priority: c_int) c_int;
-pub extern "c" fn pthread_attr_get_qos_class_np(attr: *pthread_attr_t, qos_class: *qos_class_t, relative_priority: *c_int) c_int;
-pub extern "c" fn pthread_set_qos_class_self_np(qos_class: qos_class_t, relative_priority: c_int) c_int;
-pub extern "c" fn pthread_get_qos_class_np(pthread: std.c.pthread_t, qos_class: *qos_class_t, relative_priority: *c_int) c_int;
-
-pub const CCryptorStatus = enum(i32) {
-    /// Operation completed
-    kCCSuccess = 0,
-    /// Illegal parameter
-    kCCParamError = -4300,
-    /// Provided buffer too small
-    kCCBufferTooSmall = -4301,
-    /// Failed memory allocation
-    kCCMemoryFailure = -4302,
-    /// Size alignment issue
-    kCCAlignmentError = -4303,
-    /// Decoding issue
-    kCCDecodeError = -4304,
-    /// Call not implemented
-    kCCUnimplemented = -4305,
-    kCCOverflow = -4306,
-    kCCRNGFailure = -4307,
-    /// Unspecified error
-    kCCUnspecifiedError = -4308,
-    kCCCallSequenceError = -4309,
-    kCCKeySizeError = -4310,
-    /// Invalid key
-    kCCInvalidKey = -4311,
-};
-
-pub const CCRNGStatus = CCryptorStatus;
 
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
-pub extern "c" fn CCRandomGenerateBytes(bytes: ?*anyopaque, count: usize) CCRNGStatus;
 
 // Grand Central Dispatch is exposed by libSystem.
 pub extern "c" fn dispatch_release(object: *anyopaque) void;
@@ -3896,280 +3791,3 @@ pub fn machTaskForPid(pid: std.os.pid_t) MachError!MachTask {
 pub fn machTaskForSelf() MachTask {
     return .{ .port = mach_task_self() };
 }
-
-pub const os_signpost_id_t = u64;
-
-pub const OS_SIGNPOST_ID_NULL: os_signpost_id_t = 0;
-pub const OS_SIGNPOST_ID_INVALID: os_signpost_id_t = !0;
-pub const OS_SIGNPOST_ID_EXCLUSIVE: os_signpost_id_t = 0xeeeeb0b5b2b2eeee;
-
-pub const os_log_t = opaque {};
-pub const os_log_type_t = enum(u8) {
-    /// default messages always captures
-    OS_LOG_TYPE_DEFAULT = 0x00,
-    /// messages with additional infos
-    OS_LOG_TYPE_INFO = 0x01,
-    /// debug messages
-    OS_LOG_TYPE_DEBUG = 0x02,
-    /// error messages
-    OS_LOG_TYPE_ERROR = 0x10,
-    /// unexpected conditions messages
-    OS_LOG_TYPE_FAULT = 0x11,
-};
-
-pub const OS_LOG_CATEGORY_POINTS_OF_INTEREST: *const u8 = "PointsOfInterest";
-pub const OS_LOG_CATEGORY_DYNAMIC_TRACING: *const u8 = "DynamicTracing";
-pub const OS_LOG_CATEGORY_DYNAMIC_STACK_TRACING: *const u8 = "DynamicStackTracing";
-
-pub extern "c" fn os_log_create(subsystem: [*]const u8, category: [*]const u8) os_log_t;
-pub extern "c" fn os_log_type_enabled(log: os_log_t, tpe: os_log_type_t) bool;
-pub extern "c" fn os_signpost_id_generate(log: os_log_t) os_signpost_id_t;
-pub extern "c" fn os_signpost_interval_begin(log: os_log_t, signpos: os_signpost_id_t, func: [*]const u8, ...) void;
-pub extern "c" fn os_signpost_interval_end(log: os_log_t, signpos: os_signpost_id_t, func: [*]const u8, ...) void;
-pub extern "c" fn os_signpost_id_make_with_pointer(log: os_log_t, ptr: ?*anyopaque) os_signpost_id_t;
-pub extern "c" fn os_signpost_enabled(log: os_log_t) bool;
-
-pub extern "c" fn proc_listpids(tpe: u32, tinfo: u32, buffer: ?*anyopaque, buffersize: c_int) c_int;
-pub extern "c" fn proc_listallpids(buffer: ?*anyopaque, buffersize: c_int) c_int;
-pub extern "c" fn proc_listpgrppids(pgrpid: pid_t, buffer: ?*anyopaque, buffersize: c_int) c_int;
-pub extern "c" fn proc_listchildpids(ppid: pid_t, buffer: ?*anyopaque, buffersize: c_int) c_int;
-pub extern "c" fn proc_pidinfo(pid: c_int, flavor: c_int, arg: u64, buffer: ?*anyopaque, buffersize: c_int) c_int;
-pub extern "c" fn proc_name(pid: c_int, buffer: ?*anyopaque, buffersize: u32) c_int;
-pub extern "c" fn proc_pidpath(pid: c_int, buffer: ?*anyopaque, buffersize: u32) c_int;
-
-pub const MIN = struct {
-    pub const INCORE = 0x1;
-    pub const REFERENCED = 0x2;
-    pub const MODIFIED = 0x4;
-    pub const REFERENCED_OTHER = 0x8;
-    pub const MODIFIED_OTHER = 0x10;
-    pub const PAGED_OUT = 0x20;
-    pub const COPIED = 0x40;
-    pub const ANONYMOUS = 0x80;
-};
-
-pub extern "c" fn mincore(addr: *align(std.mem.page_size) const anyopaque, length: usize, vec: [*]u8) c_int;
-pub extern "c" fn os_proc_available_memory() usize;
-
-pub const thread_affinity_policy = extern struct {
-    tag: integer_t,
-};
-
-pub const thread_policy_flavor_t = natural_t;
-pub const thread_policy_t = [*]integer_t;
-pub const thread_affinity_policy_data_t = thread_affinity_policy;
-pub const thread_affinity_policy_t = [*]thread_affinity_policy;
-
-pub const THREAD_AFFINITY = struct {
-    pub const POLICY = 0;
-    pub const POLICY_COUNT = @as(mach_msg_type_number_t, @intCast(@sizeOf(thread_affinity_policy_data_t) / @sizeOf(integer_t)));
-};
-
-/// cpu affinity api
-/// albeit it is also available on arm64, it always fails as in this architecture there is no sense of
-/// individual cpus (high performance cpus group and low consumption one), thus the pthread QOS api is more appropriate in this case.
-pub extern "c" fn thread_affinity_get(thread: thread_act_t, flavor: thread_policy_flavor_t, info: thread_policy_t, infocnt: [*]mach_msg_type_number_t, default: *boolean_t) kern_return_t;
-pub extern "c" fn thread_affinity_set(thread: thread_act_t, flavor: thread_policy_flavor_t, info: thread_policy_t, infocnt: mach_msg_type_number_t) kern_return_t;
-
-pub const cpu_type_t = integer_t;
-pub const cpu_subtype_t = integer_t;
-pub const cpu_threadtype_t = integer_t;
-pub const host_flavor_t = integer_t;
-pub const host_info_t = *integer_t;
-pub const host_info64_t = *integer_t;
-pub const host_can_has_debugger_info = extern struct {
-    can_has_debugger: boolean_t,
-};
-pub const host_can_has_debugger_info_data_t = host_can_has_debugger_info;
-pub const host_can_has_debugger_info_t = *host_can_has_debugger_info;
-
-pub const host_sched_info = extern struct {
-    min_timeout: integer_t,
-    min_quantum: integer_t,
-};
-pub const host_sched_info_data_t = host_sched_info;
-pub const host_sched_info_t = *host_sched_info;
-
-pub const kernel_resource_sizes = extern struct {
-    task: natural_t,
-    thread: natural_t,
-    port: natural_t,
-    memory_region: natural_t,
-    memory_object: natural_t,
-};
-
-pub const kernel_resource_sizes_data_t = kernel_resource_sizes;
-pub const kernel_resource_sizes_t = *kernel_resource_sizes;
-
-pub const host_priority_info = extern struct {
-    kernel_priority: integer_t,
-    system_priority: integer_t,
-    server_priority: integer_t,
-    user_priority: integer_t,
-    depress_priority: integer_t,
-    idle_priority: integer_t,
-    minimum_priority: integer_t,
-    maximum_priority: integer_t,
-};
-
-pub const host_priority_info_data_t = host_priority_info;
-pub const host_priority_info_t = *host_priority_info;
-
-pub const CPU_STATE_MAX = 4;
-
-pub const host_cpu_load_info = extern struct {
-    cpu_ticks: [CPU_STATE_MAX]natural_t,
-};
-
-pub const host_cpu_load_info_data_t = host_cpu_load_info;
-pub const host_cpu_load_info_t = *host_cpu_load_info;
-
-pub const host_load_info = extern struct {
-    avenrun: [3]integer_t,
-    mach_factor: [3]integer_t,
-};
-
-pub const host_load_info_data_t = host_load_info;
-pub const host_load_info_t = *host_load_info;
-
-pub const host_preferred_user_arch = extern struct {
-    cpu_type: cpu_type_t,
-    cpu_subtype: cpu_subtype_t,
-};
-
-pub const host_preferred_user_arch_data_t = host_preferred_user_arch;
-pub const host_preferred_user_arch_t = *host_preferred_user_arch;
-
-fn HostCount(comptime HT: type) mach_msg_type_number_t {
-    return @as(mach_msg_type_number_t, @intCast(@sizeOf(HT) / @sizeOf(integer_t)));
-}
-
-pub const HOST = struct {
-    pub const BASIC_INFO = 1;
-    pub const SCHED_INFO = 3;
-    pub const RESOURCE_SIZES = 4;
-    pub const PRIORITY_INFO = 5;
-    pub const SEMAPHORE_TRAPS = 7;
-    pub const MACH_MSG_TRAPS = 8;
-    pub const VM_PURGEABLE = 9;
-    pub const DEBUG_INFO_INTERNAL = 10;
-    pub const CAN_HAS_DEBUGGER = 11;
-    pub const PREFERRED_USER_ARCH = 12;
-    pub const LOAD_INFO = 1;
-    pub const VM_INFO = 2;
-    pub const CPU_LOAD_INFO = 3;
-    pub const VM_INFO64 = 4;
-    pub const EXTMOD_INFO64 = 5;
-    pub const EXPIRED_TASK_INFO = 6;
-    pub const CAN_HAS_DEBUGGER_COUNT = HostCount(host_can_has_debugger_info_data_t);
-    pub const SCHED_INFO_COUNT = HostCount(host_sched_info_data_t);
-    pub const RESOURCES_SIZES_COUNT = HostCount(kernel_resource_sizes_data_t);
-    pub const PRIORITY_INFO_COUNT = HostCount(host_priority_info_data_t);
-    pub const CPU_LOAD_INFO_COUNT = HostCount(host_cpu_load_info_data_t);
-    pub const LOAD_INFO_COUNT = HostCount(host_load_info_data_t);
-    pub const PREFERRED_USER_ARCH_COUNT = HostCount(host_preferred_user_arch_data_t);
-    pub const VM_INFO_COUNT = HostCount(vm_statistics_data_t);
-    pub const VM_INFO64_COUNT = HostCount(vm_statistics64_data_t);
-    pub const EXTMOD_INFO64_COUNT = HostCount(vm_extmod_statistics_data_t);
-};
-
-pub const host_basic_info = extern struct {
-    max_cpus: integer_t,
-    avail_cpus: integer_t,
-    memory_size: natural_t,
-    cpu_type: cpu_type_t,
-    cpu_subtype: cpu_subtype_t,
-    cpu_threadtype: cpu_threadtype_t,
-    physical_cpu: integer_t,
-    physical_cpu_max: integer_t,
-    logical_cpu: integer_t,
-    logical_cpu_max: integer_t,
-    max_mem: u64,
-};
-
-pub extern "c" fn host_info(host: host_t, flavor: host_flavor_t, info_out: host_info_t, info_outCnt: [*]mach_msg_type_number_t) kern_return_t;
-pub extern "c" fn host_statistics(priv: host_t, flavor: host_flavor_t, info_out: host_info_t, info_outCnt: [*]mach_msg_type_number_t) kern_return_t;
-pub extern "c" fn host_statistics64(priv: host_t, flavor: host_flavor_t, info_out: host_info64_t, info64_outCnt: [*]mach_msg_type_number_t) kern_return_t;
-
-pub const vm_statistics = extern struct {
-    free_count: natural_t,
-    active_count: natural_t,
-    inactive_count: natural_t,
-    wire_count: natural_t,
-    zero_fill_count: natural_t,
-    reactivations: natural_t,
-    pageins: natural_t,
-    pageouts: natural_t,
-    faults: natural_t,
-    cow_faults: natural_t,
-    lookups: natural_t,
-    hits: natural_t,
-    purgeable_count: natural_t,
-    purges: natural_t,
-    speculative_count: natural_t,
-};
-
-pub const vm_statistics_t = *vm_statistics;
-pub const vm_statistics_data_t = vm_statistics;
-
-pub const vm_statistics64 align(8) = extern struct {
-    free_count: natural_t,
-    active_count: natural_t,
-    inactive_count: natural_t,
-    wire_count: natural_t,
-    zero_fill_count: u64,
-    reactivations: u64,
-    pageins: u64,
-    pageouts: u64,
-    faults: u64,
-    cow_faults: u64,
-    lookups: u64,
-    hits: u64,
-    purges: u64,
-    purgeable_count: natural_t,
-    speculative_count: natural_t,
-    decompressions: u64,
-    compressions: u64,
-    swapins: u64,
-    swapouts: u64,
-    compressor_page_count: natural_t,
-    throttled_count: natural_t,
-    external_page_count: natural_t,
-    internal_page_count: natural_t,
-    total_uncompressed_pages_in_compressor: u64,
-};
-
-pub const vm_statistics64_t = *vm_statistics64;
-pub const vm_statistics64_data_t = vm_statistics64;
-
-pub const vm_extmod_statistics align(8) = extern struct {
-    task_for_pid_count: i64,
-    task_for_pid_caller_count: i64,
-    thread_creation_count: i64,
-    thread_creation_caller_count: i64,
-    thread_set_state_count: i64,
-    thread_set_state_caller_count: i64,
-};
-
-pub const vm_extmod_statistics_t = *vm_extmod_statistics;
-pub const vm_extmod_statistics_data_t = vm_extmod_statistics;
-
-pub extern "c" fn vm_stats(info: ?*anyopaque, count: *c_uint) kern_return_t;
-
-/// TODO refines if necessary
-pub const PTHREAD_STACK_MIN = switch (builtin.cpu.arch) {
-    .arm, .aarch64 => 16 * 1024,
-    else => 8 * 1024,
-};
-
-pub const _SYS_NAMELEN = 256;
-
-pub const utsname = extern struct {
-    sysname: [255:0]u8,
-    nodename: [255:0]u8,
-    release: [255:0]u8,
-    version: [255:0]u8,
-    machine: [255:0]u8,
-};
-
-pub extern "c" fn uname(u: *utsname) c_int;
diff --git a/lib/std/c/dragonfly.zig b/lib/std/c/dragonfly.zig
index f18e1932257b..d4f2867fda3a 100644
--- a/lib/std/c/dragonfly.zig
+++ b/lib/std/c/dragonfly.zig
@@ -21,7 +21,6 @@ pub extern "c" fn dl_iterate_phdr(callback: dl_iterate_phdr_callback, data: ?*an
 pub extern "c" fn lwp_gettid() c_int;
 
 pub extern "c" fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: usize) c_int;
-pub extern "c" fn malloc_usable_size(?*const anyopaque) usize;
 
 pub const pthread_mutex_t = extern struct {
     inner: ?*anyopaque = null,
@@ -889,13 +888,13 @@ pub const cmsghdr = extern struct {
     cmsg_type: c_int,
 };
 pub const msghdr = extern struct {
-    name: ?*anyopaque,
-    namelen: socklen_t,
-    iov: [*]iovec,
-    iovlen: c_int,
-    control: ?*anyopaque,
-    controllen: socklen_t,
-    flags: c_int,
+    msg_name: ?*anyopaque,
+    msg_namelen: socklen_t,
+    msg_iov: [*]iovec,
+    msg_iovlen: c_int,
+    msg_control: ?*anyopaque,
+    msg_controllen: socklen_t,
+    msg_flags: c_int,
 };
 pub const cmsgcred = extern struct {
     cmcred_pid: pid_t,
@@ -1144,24 +1143,3 @@ pub const POLL = struct {
     pub const HUP = 0x0010;
     pub const NVAL = 0x0020;
 };
-
-pub const SIGEV = struct {
-    pub const NONE = 0;
-    pub const SIGNAL = 1;
-    pub const THREAD = 2;
-};
-
-pub const sigevent = extern struct {
-    sigev_notify: c_int,
-    __sigev_u: extern union {
-        __sigev_signo: c_int,
-        __sigev_notify_kqueue: c_int,
-        __sigev_notify_attributes: ?*pthread_attr_t,
-    },
-    sigev_value: sigval,
-    sigev_notify_function: ?*const fn (sigval) callconv(.C) void,
-};
-
-pub const PTHREAD_STACK_MIN = 16 * 1024;
-
-pub const timer_t = *opaque {};
diff --git a/lib/std/c/emscripten.zig b/lib/std/c/emscripten.zig
index 8b9fd8c2a27d..0d78d4d73f27 100644
--- a/lib/std/c/emscripten.zig
+++ b/lib/std/c/emscripten.zig
@@ -9,5 +9,3 @@ pub const pthread_rwlock_t = extern struct {
 };
 const __SIZEOF_PTHREAD_COND_T = 48;
 const __SIZEOF_PTHREAD_MUTEX_T = 28;
-
-pub const PTHREAD_STACK_MIN = 2048;
diff --git a/lib/std/c/freebsd.zig b/lib/std/c/freebsd.zig
index 16b404fbdaa0..84891be74cfc 100644
--- a/lib/std/c/freebsd.zig
+++ b/lib/std/c/freebsd.zig
@@ -5,80 +5,12 @@ const maxInt = std.math.maxInt;
 const iovec = std.os.iovec;
 const iovec_const = std.os.iovec_const;
 
-pub const CPU_SETSIZE = 256;
-pub const cpuset_t = extern struct {
-    __bits: [(CPU_SETSIZE + (@bitSizeOf(c_long) - 1)) / @bitSizeOf(c_long)]c_long,
-};
-
-fn __BIT_COUNT(bits: []const c_long) c_long {
-    var count: c_long = 0;
-    for (bits) |b| {
-        count += @popCount(b);
-    }
-    return count;
-}
-
-fn __BIT_MASK(s: usize) c_long {
-    var x = s % CPU_SETSIZE;
-    return @as(c_long, @bitCast(@as(c_ulong, @intCast(1)) << @as(u6, @intCast(x))));
-}
-
-pub fn CPU_COUNT(set: cpuset_t) c_int {
-    return @as(c_int, @intCast(__BIT_COUNT(set.__bits[0..])));
-}
-
-pub fn CPU_ZERO(set: *cpuset_t) void {
-    @memset((set.*).__bits[0..], 0);
-}
-
-pub fn CPU_SET(cpu: usize, set: *cpuset_t) void {
-    const x = cpu / @sizeOf(c_long);
-    if (x < @sizeOf(cpuset_t)) {
-        (set.*).__bits[x] |= __BIT_MASK(x);
-    }
-}
-
-pub fn CPU_ISSET(cpu: usize, set: cpuset_t) bool {
-    const x = cpu / @sizeOf(c_long);
-    if (x < @sizeOf(cpuset_t)) {
-        return set.__bits[x] & __BIT_MASK(x) != 0;
-    }
-    return false;
-}
-
-pub fn CPU_CLR(cpu: usize, set: *cpuset_t) void {
-    const x = cpu / @sizeOf(c_long);
-    if (x < @sizeOf(cpuset_t)) {
-        (set.*).__bits[x] &= !__BIT_MASK(x);
-    }
-}
-
-pub const cpulevel_t = c_int;
-pub const cpuwhich_t = c_int;
-pub const id_t = i64;
-
-pub const CPU_LEVEL_ROOT: cpulevel_t = 1;
-pub const CPU_LEVEL_CPUSET: cpulevel_t = 2;
-pub const CPU_LEVEL_WHICH: cpulevel_t = 3;
-pub const CPU_WHICH_TID: cpuwhich_t = 1;
-pub const CPU_WHICH_PID: cpuwhich_t = 2;
-pub const CPU_WHICH_CPUSET: cpuwhich_t = 3;
-pub const CPU_WHICH_IRQ: cpuwhich_t = 4;
-pub const CPU_WHICH_JAIL: cpuwhich_t = 5;
-pub const CPU_WHICH_DOMAIN: cpuwhich_t = 6;
-pub const CPU_WHICH_INTRHANDLER: cpuwhich_t = 7;
-pub const CPU_WHICH_ITHREAD: cpuwhich_t = 8;
-pub const CPU_WHICH_TIDPID: cpuwhich_t = 8;
-
 extern "c" fn __error() *c_int;
 pub const _errno = __error;
 
-pub extern "c" var malloc_options: [*:0]const u8;
-
-pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) isize;
+pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) usize;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
 pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize;
-pub extern "c" fn getentropy(buf_ptr: [*]u8, buf_len: usize) c_int;
 
 pub extern "c" fn pthread_getthreadid_np() c_int;
 pub extern "c" fn pthread_set_name_np(thread: std.c.pthread_t, name: [*:0]const u8) void;
@@ -88,21 +20,10 @@ pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
 
 pub extern "c" fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: usize) c_int;
 pub extern "c" fn malloc_usable_size(?*const anyopaque) usize;
-pub extern "c" fn reallocf(?*anyopaque, usize) ?*anyopaque;
 
 pub extern "c" fn getpid() pid_t;
 
 pub extern "c" fn kinfo_getfile(pid: pid_t, cntp: *c_int) ?[*]kinfo_file;
-pub extern "c" fn kinfo_getvmmap(pid: pid_t, cntp: *c_int) ?[*]kinfo_vmentry;
-pub extern "c" fn kinfo_getproc(pid: pid_t) ?*kinfo_proc;
-pub extern "c" fn kinfo_getvmobject(cntp: *c_int) ?[*]kinfo_vmobject;
-pub extern "c" fn kinfo_getswapvmobject(cntp: *c_int) ?[*]kinfo_vmobject;
-
-pub extern "c" fn cpuset_getaffinity(level: cpulevel_t, which: cpuwhich_t, id: id_t, setsize: usize, mask: *cpuset_t) c_int;
-pub extern "c" fn cpuset_setaffinity(level: cpulevel_t, which: cpuwhich_t, id: id_t, setsize: usize, mask: *const cpuset_t) c_int;
-pub extern "c" fn sched_getaffinity(pid: pid_t, cpusetsz: usize, cpuset: *cpuset_t) c_int;
-pub extern "c" fn sched_setaffinity(pid: pid_t, cpusetsz: usize, cpuset: *const cpuset_t) c_int;
-pub extern "c" fn sched_getcpu() c_int;
 
 pub const sf_hdtr = extern struct {
     headers: [*]const iovec_const,
@@ -355,36 +276,36 @@ pub const Flock = extern struct {
 
 pub const msghdr = extern struct {
     /// Optional address.
-    name: ?*sockaddr,
+    msg_name: ?*sockaddr,
     /// Size of address.
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
     /// Scatter/gather array.
-    iov: [*]iovec,
+    msg_iov: [*]iovec,
     /// Number of elements in msg_iov.
-    iovlen: i32,
+    msg_iovlen: i32,
     /// Ancillary data.
-    control: ?*anyopaque,
+    msg_control: ?*anyopaque,
     /// Ancillary data buffer length.
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
     /// Flags on received message.
-    flags: i32,
+    msg_flags: i32,
 };
 
 pub const msghdr_const = extern struct {
     /// Optional address.
-    name: ?*const sockaddr,
+    msg_name: ?*const sockaddr,
     /// Size of address.
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
     /// Scatter/gather array.
-    iov: [*]iovec_const,
+    msg_iov: [*]iovec_const,
     /// Number of elements in msg_iov.
-    iovlen: i32,
+    msg_iovlen: i32,
     /// Ancillary data.
-    control: ?*anyopaque,
+    msg_control: ?*anyopaque,
     /// Ancillary data buffer length.
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
     /// Flags on received message.
-    flags: i32,
+    msg_flags: i32,
 };
 
 pub const Stat = extern struct {
@@ -523,43 +444,10 @@ pub const sockaddr = extern struct {
 
 pub const CAP_RIGHTS_VERSION = 0;
 
-pub const cap_rights_t = extern struct {
-    cr_rights: [CAP_RIGHTS_VERSION + 2]u64,
+pub const cap_rights = extern struct {
+    rights: [CAP_RIGHTS_VERSION + 2]u64,
 };
 
-pub const CAP = struct {
-    pub fn RIGHT(idx: u6, bit: u64) u64 {
-        return (@as(u64, @intCast(1)) << (57 + idx)) | bit;
-    }
-    pub const READ = CAP.RIGHT(0, 0x0000000000000001);
-    pub const WRITE = CAP.RIGHT(0, 0x0000000000000002);
-    pub const SEEK_TELL = CAP.RIGHT(0, 0x0000000000000004);
-    pub const SEEK = CAP.SEEK_TELL | 0x0000000000000008;
-    pub const PREAD = CAP.SEEK | CAP.READ;
-    pub const PWRITE = CAP.SEEK | CAP.WRITE;
-    pub const MMAP = CAP.RIGHT(0, 0x0000000000000010);
-    pub const MMAP_R = CAP.MMAP | CAP.SEEK | CAP.READ;
-    pub const MMAP_W = CAP.MMAP | CAP.SEEK | CAP.WRITE;
-    pub const MMAP_X = CAP.MMAP | CAP.SEEK | 0x0000000000000020;
-    pub const MMAP_RW = CAP.MMAP_R | CAP.MMAP_W;
-    pub const MMAP_RX = CAP.MMAP_R | CAP.MMAP_X;
-    pub const MMAP_WX = CAP.MMAP_W | CAP.MMAP_X;
-    pub const MMAP_RWX = CAP.MMAP_R | CAP.MMAP_W | CAP.MMAP_X;
-    pub const CREATE = CAP.RIGHT(0, 0x0000000000000040);
-    pub const FEXECVE = CAP.RIGHT(0, 0x0000000000000080);
-    pub const FSYNC = CAP.RIGHT(0, 0x0000000000000100);
-    pub const FTRUNCATE = CAP.RIGHT(0, 0x0000000000000200);
-};
-
-pub extern "c" fn __cap_rights_init(version: c_int, rights: ?*cap_rights_t, ...) ?*cap_rights_t;
-pub extern "c" fn __cap_rights_set(rights: ?*cap_rights_t, ...) ?*cap_rights_t;
-pub extern "c" fn __cap_rights_clear(rights: ?*cap_rights_t, ...) ?*cap_rights_t;
-pub extern "c" fn __cap_rights_is_set(rights: ?*const cap_rights_t, ...) bool;
-pub extern "c" fn cap_rights_merge(dst: ?*cap_rights_t, src: ?*const cap_rights_t) ?*cap_rights_t;
-pub extern "c" fn cap_rights_remove(dst: ?*cap_rights_t, src: ?*const cap_rights_t) ?*cap_rights_t;
-pub extern "c" fn cap_rights_contains(dst: ?*const cap_rights_t, src: ?*const cap_rights_t) bool;
-pub extern "c" fn cap_rights_is_valid(rights: ?*const cap_rights_t) bool;
-
 pub const kinfo_file = extern struct {
     /// Size of this record.
     /// A zero value is for the sentinel record at the end of an array.
@@ -661,7 +549,7 @@ pub const kinfo_file = extern struct {
     // Reserved for future use.
     _spare: c_int,
     /// Capability rights.
-    cap_rights: cap_rights_t,
+    cap_rights: cap_rights,
     /// Reserved for future cap_rights
     _cap_spare: u64,
     /// Path to file, if any.
@@ -675,248 +563,6 @@ comptime {
     std.debug.assert(@alignOf(kinfo_file) == @sizeOf(u64));
 }
 
-pub const kinfo_vmentry = extern struct {
-    structsize: c_int,
-    type: c_int,
-    start: u64,
-    end: u64,
-    offset: u64,
-    vn_fileid: u64,
-    vn_fsid_freebsd11: u32,
-    flags: c_int,
-    resident: c_int,
-    private_resident: c_int,
-    protection: c_int,
-    ref_count: c_int,
-    shadow_count: c_int,
-    vn_type: c_int,
-    vn_size: u64,
-    vn_rdev_freebsd11: u32,
-    vn_mode: u16,
-    status: u16,
-    type_spec: extern union {
-        _vn_fsid: u64,
-        _obj: u64,
-    },
-    vn_rdev: u64,
-    _ispare: [8]c_int,
-    rpath: [PATH_MAX]u8,
-};
-
-pub const KINFO_VMENTRY_SIZE = 1160;
-
-comptime {
-    std.debug.assert(@sizeOf(kinfo_vmentry) == KINFO_VMENTRY_SIZE);
-}
-
-pub const WMESGLEN = 8;
-pub const LOCKNAMELEN = 8;
-pub const TDNAMLEN = 16;
-pub const COMMLEN = 19;
-pub const MAXCOMLEN = 19;
-pub const KI_EMULNAMELEN = 16;
-pub const KI_NGROUPS = 16;
-pub const LOGNAMELEN = 17;
-pub const LOGINCLASSLEN = 17;
-
-pub const KI_NSPARE_INT = 2;
-pub const KI_NSPARE_LONG = 12;
-pub const KI_NSPARE_PTR = 5;
-
-pub const RUSAGE_SELF = 0;
-pub const RUSAGE_CHILDREN = -1;
-pub const RUSAGE_THREAD = 1;
-
-pub const proc = opaque {};
-pub const thread = opaque {};
-pub const vnode = opaque {};
-pub const filedesc = opaque {};
-pub const pwddesc = opaque {};
-pub const vmspace = opaque {};
-pub const pcb = opaque {};
-pub const lwpid_t = i32;
-pub const fixpt_t = u32;
-pub const vm_size_t = usize;
-pub const segsz_t = isize;
-
-pub const itimerval = extern struct {
-    interval: timeval,
-    value: timeval,
-};
-
-pub const pstats = extern struct {
-    cru: rusage,
-    timer: [3]itimerval,
-    prof: extern struct {
-        base: u8,
-        size: c_ulong,
-        off: c_ulong,
-        scale: c_ulong,
-    },
-    start: timeval,
-};
-
-pub const user = extern struct {
-    stats: pstats,
-    kproc: kinfo_proc,
-};
-
-pub const pargs = extern struct {
-    ref: c_uint,
-    length: c_uint,
-    args: [1]u8,
-};
-
-pub const priority = extern struct {
-    class: u8,
-    level: u8,
-    native: u8,
-    user: u8,
-};
-
-pub const rusage = extern struct {
-    utime: timeval,
-    stime: timeval,
-    maxrss: c_long,
-    ixrss: c_long,
-    idrss: c_long,
-    isrss: c_long,
-    minflt: c_long,
-    majflt: c_long,
-    nswap: c_long,
-    inblock: c_long,
-    oublock: c_long,
-    msgsnd: c_long,
-    msgrcv: c_long,
-    nsignals: c_long,
-    nvcsw: c_long,
-    nivcsw: c_long,
-};
-
-pub const kinfo_proc = extern struct {
-    structsize: c_int,
-    layout: c_int,
-    args: *pargs,
-    paddr: *proc,
-    addr: *user,
-    tracep: *vnode,
-    textvp: *vnode,
-    fd: *filedesc,
-    vmspace: *vmspace,
-    wchan: ?*const anyopaque,
-    pid: pid_t,
-    ppid: pid_t,
-    pgid: pid_t,
-    tpgid: pid_t,
-    sid: pid_t,
-    tsid: pid_t,
-    jobc: c_short,
-    spare_short1: c_short,
-    tdev_freebsd11: u32,
-    siglist: sigset_t,
-    sigmask: sigset_t,
-    sigignore: sigset_t,
-    sigcatch: sigset_t,
-    uid: uid_t,
-    ruid: uid_t,
-    svuid: uid_t,
-    rgid: gid_t,
-    svgid: gid_t,
-    ngroups: c_short,
-    spare_short2: c_short,
-    groups: [KI_NGROUPS]gid_t,
-    size: vm_size_t,
-    rssize: segsz_t,
-    swrss: segsz_t,
-    tsize: segsz_t,
-    dsize: segsz_t,
-    ssize: segsz_t,
-    xstat: c_ushort,
-    acflag: c_ushort,
-    pctcpu: fixpt_t,
-    estcpu: c_uint,
-    slptime: c_uint,
-    swtime: c_uint,
-    cow: c_uint,
-    runtime: u64,
-    start: timeval,
-    childtime: timeval,
-    flag: c_long,
-    kiflag: c_long,
-    traceflag: c_int,
-    stat: u8,
-    nice: i8,
-    lock: u8,
-    rqindex: u8,
-    oncpu_old: u8,
-    lastcpu_old: u8,
-    tdname: [TDNAMLEN + 1]u8,
-    wmesg: [WMESGLEN + 1]u8,
-    login: [LOGNAMELEN + 1]u8,
-    lockname: [LOCKNAMELEN + 1]u8,
-    comm: [COMMLEN + 1]u8,
-    emul: [KI_EMULNAMELEN + 1]u8,
-    loginclass: [LOGINCLASSLEN + 1]u8,
-    moretdname: [MAXCOMLEN - TDNAMLEN + 1]u8,
-    sparestrings: [46]u8,
-    spareints: [KI_NSPARE_INT]c_int,
-    tdev: u64,
-    oncpu: c_int,
-    lastcpu: c_int,
-    tracer: c_int,
-    flag2: c_int,
-    fibnum: c_int,
-    cr_flags: c_uint,
-    jid: c_int,
-    numthreads: c_int,
-    tid: lwpid_t,
-    pri: priority,
-    rusage: rusage,
-    rusage_ch: rusage,
-    pcb: *pcb,
-    stack: ?*anyopaque,
-    udata: ?*anyopaque,
-    tdaddr: *thread,
-    pd: *pwddesc,
-    spareptrs: [KI_NSPARE_PTR]?*anyopaque,
-    sparelongs: [KI_NSPARE_LONG]c_long,
-    sflag: c_long,
-    tdflag: c_long,
-};
-
-pub const KINFO_PROC_SIZE = switch (builtin.cpu.arch) {
-    .x86 => 768,
-    .arm => 816,
-    else => 1088,
-};
-
-comptime {
-    assert(@sizeOf(kinfo_proc) == KINFO_PROC_SIZE);
-}
-
-pub const kinfo_vmobject = extern struct {
-    structsize: c_int,
-    tpe: c_int,
-    size: u64,
-    vn_fileid: u64,
-    vn_fsid_freebsd11: u32,
-    ref_count: c_int,
-    shadow_count: c_int,
-    memattr: c_int,
-    resident: u64,
-    active: u64,
-    inactive: u64,
-    type_spec: extern union {
-        _vn_fsid: u64,
-        _backing_obj: u64,
-    },
-    me: u64,
-    _qspare: [6]u64,
-    swapped: u32,
-    _ispare: [7]u32,
-    path: [PATH_MAX]u8,
-};
-
 pub const CTL = struct {
     pub const KERN = 1;
     pub const DEBUG = 5;
@@ -976,25 +622,6 @@ pub const MAP = struct {
     pub const NOCORE = 0x00020000;
     pub const PREFAULT_READ = 0x00040000;
     pub const @"32BIT" = 0x00080000;
-
-    pub fn ALIGNED(alignment: u32) u32 {
-        return alignment << 24;
-    }
-    pub const ALIGNED_SUPER = ALIGNED(1);
-};
-
-pub const MADV = struct {
-    pub const NORMAL = 0;
-    pub const RANDOM = 1;
-    pub const SEQUENTIAL = 2;
-    pub const WILLNEED = 3;
-    pub const DONTNEED = 4;
-    pub const FREE = 5;
-    pub const NOSYNC = 6;
-    pub const AUTOSYNC = 7;
-    pub const NOCORE = 8;
-    pub const CORE = 9;
-    pub const PROTECT = 10;
 };
 
 pub const MSF = struct {
@@ -1396,11 +1023,6 @@ pub const DT = struct {
     pub const WHT = 14;
 };
 
-pub const accept_filter = extern struct {
-    af_name: [16]u8,
-    af_args: [240]u8,
-};
-
 /// add event to kq (implies enable)
 pub const EV_ADD = 0x0001;
 
@@ -1682,47 +1304,15 @@ pub const mcontext_t = switch (builtin.cpu.arch) {
         rflags: u64,
         rsp: u64,
         ss: u64,
-        len: c_long,
-        fpformat: c_long,
-        ownedfp: c_long,
-        fpstate: [64]c_long align(16),
+        len: u64,
+        fpformat: u64,
+        ownedfp: u64,
+        fpstate: [64]u64 align(16),
         fsbase: u64,
         gsbase: u64,
         xfpustate: u64,
         xfpustate_len: u64,
-        spare: [4]c_long,
-    },
-    .x86 => extern struct {
-        onstack: u32,
-        gs: u32,
-        fs: u32,
-        es: u32,
-        ds: u32,
-        edi: u32,
-        esi: u32,
-        ebp: u32,
-        isp: u32,
-        ebx: u32,
-        edx: u32,
-        ecx: u32,
-        eax: u32,
-        trapno: u32,
-        err: u32,
-        eip: u32,
-        cs: u32,
-        eflags: u32,
-        esp: u32,
-        ss: u32,
-        len: c_int,
-        fpformat: c_int,
-        ownedfp: c_int,
-        flags: u32,
-        fpstate: [128]c_int align(16),
-        fsbase: u32,
-        gsbase: u32,
-        xpustate: u32,
-        xpustate_len: u32,
-        spare2: [4]c_int,
+        spare: [4]u64,
     },
     .aarch64 => extern struct {
         gpregs: extern struct {
@@ -2002,45 +1592,6 @@ pub const AT = struct {
     pub const REMOVEDIR = 0x0800;
     /// Fail if not under dirfd
     pub const BENEATH = 0x1000;
-    /// elf_common constants
-    pub const NULL = 0;
-    pub const IGNORE = 1;
-    pub const EXECFD = 2;
-    pub const PHDR = 3;
-    pub const PHENT = 4;
-    pub const PHNUM = 5;
-    pub const PAGESZ = 6;
-    pub const BASE = 7;
-    pub const FLAGS = 8;
-    pub const ENTRY = 9;
-    pub const NOTELF = 10;
-    pub const UID = 11;
-    pub const EUID = 12;
-    pub const GID = 13;
-    pub const EGID = 14;
-    pub const EXECPATH = 15;
-    pub const CANARY = 16;
-    pub const CANARYLEN = 17;
-    pub const OSRELDATE = 18;
-    pub const NCPUS = 19;
-    pub const PAGESIZES = 20;
-    pub const PAGESIZESLEN = 21;
-    pub const TIMEKEEP = 22;
-    pub const STACKPROT = 23;
-    pub const EHDRFLAGS = 24;
-    pub const HWCAP = 25;
-    pub const HWCAP2 = 26;
-    pub const BSDFLAGS = 27;
-    pub const ARGC = 28;
-    pub const ARGV = 29;
-    pub const ENVC = 30;
-    pub const ENVV = 31;
-    pub const PS_STRINGS = 32;
-    pub const FXRNG = 33;
-    pub const KPRLOAD = 34;
-    pub const USRSTACKBASE = 35;
-    pub const USRSTACKLIM = 36;
-    pub const COUNT = 37;
 };
 
 pub const addrinfo = extern struct {
@@ -2373,468 +1924,7 @@ pub const NAME_MAX = 255;
 pub const MFD = struct {
     pub const CLOEXEC = 0x0001;
     pub const ALLOW_SEALING = 0x0002;
-    pub const HUGETLB = 0x00000004;
-    pub const HUGE_MASK = 0xFC000000;
-    pub const HUGE_SHIFT = 26;
-    pub const HUGE_64KB = 16 << HUGE_SHIFT;
-    pub const HUGE_512KB = 19 << HUGE_SHIFT;
-    pub const HUGE_1MB = 20 << HUGE_SHIFT;
-    pub const HUGE_2MB = 21 << HUGE_SHIFT;
-    pub const HUGE_8MB = 23 << HUGE_SHIFT;
-    pub const HUGE_16MB = 24 << HUGE_SHIFT;
-    pub const HUGE_32MB = 25 << HUGE_SHIFT;
-    pub const HUGE_256MB = 28 << HUGE_SHIFT;
-    pub const HUGE_512MB = 29 << HUGE_SHIFT;
-    pub const HUGE_1GB = 30 << HUGE_SHIFT;
-    pub const HUGE_2GB = 31 << HUGE_SHIFT;
-    pub const HUGE_16GB = 34 << HUGE_SHIFT;
 };
 
 pub extern "c" fn memfd_create(name: [*:0]const u8, flags: c_uint) c_int;
 pub extern "c" fn copy_file_range(fd_in: fd_t, off_in: ?*off_t, fd_out: fd_t, off_out: ?*off_t, len: usize, flags: u32) usize;
-
-pub const idtype_t = enum(c_int) {
-    P_PID = 0,
-    P_PPID = 1,
-    P_PGID = 2,
-    P_SID = 3,
-    P_CID = 4,
-    P_UID = 5,
-    P_GID = 6,
-    P_ALL = 7,
-    P_LWPID = 8,
-    P_TASKID = 9,
-    P_PROJID = 10,
-    P_POOLID = 11,
-    P_JAILID = 12,
-    P_CTID = 13,
-    P_CPUID = 14,
-    P_PSETID = 15,
-};
-
-pub const PROC = struct {
-    // constants for the id_t argument
-    pub const SPROTECT: id_t = 1;
-    pub const REAP_ACQUIRE: id_t = 2;
-    pub const REAP_RELEASE: id_t = 3;
-    pub const REAP_STATUS: id_t = 4;
-    pub const REAP_GETPIDS: id_t = 5;
-    pub const REAP_KILL: id_t = 6;
-    pub const TRACE_CTL: id_t = 7;
-    pub const TRACE_STATUS: id_t = 8;
-    pub const TRACECAP_CTL = 9;
-    pub const TRACECAP_STATUS: id_t = 10;
-    pub const PDEATHSIG_CTL: id_t = 11;
-    pub const PDEATHSIG_STATUS: id_t = 12;
-    pub const ASLR_CTL: id_t = 13;
-    pub const ASLR_STATUS: id_t = 14;
-    pub const PROTMAX_CTL: id_t = 15;
-    pub const PROTMAX_STATUS: id_t = 16;
-    pub const STACKGAP_CTL: id_t = 17;
-    pub const STACKGAP_STATUS: id_t = 18;
-    pub const NO_NEW_PRIVS_CTL: id_t = 19;
-    pub const NO_NEW_PRIVS_STATUS: id_t = 20;
-    pub const WXMAP_CTL: id_t = 21;
-    pub const WXMAP_STATUS: id_t = 22;
-
-    // constants for the operations
-    pub const TRACE_CTL_ENABLE = 1;
-    pub const TRACE_CTL_DISABLE = 2;
-    pub const TRACE_CTL_DISABLE_EXEC = 3;
-    pub const TRAPCAP_CTL_ENABLE = 1;
-    pub const TRAPCAP_CTL_DISABLE = 2;
-    pub const ASLR_FORCE_ENABLE = 1;
-    pub const ASLR_FORCE_DISABLE = 2;
-    pub const ASLR_FORCE_NOFORCE = 3;
-    pub const ASLR_FORCE_ACTIVE = 0x80000000;
-    pub const PROTMAX_FORCE_ENABLE = 1;
-    pub const PROTMAX_FORCE_DISABLE = 2;
-    pub const PROTMAX_FORCE_NOFORCE = 3;
-    pub const PROTMAX_FORCE_ACTIVE = 0x80000000;
-    pub const STACKGAP_ENABLE = 0x0001;
-    pub const STACKGAP_DISABLE = 0x0002;
-    pub const STACKGAP_ENABLE_EXEC = 0x0004;
-    pub const STACKGAP_DISABLE_EXEC = 0x0008;
-    pub const NO_NEW_PRIVS_ENABLE = 1;
-    pub const NO_NEW_PRIVS_DISABLE = 2;
-    pub const WX_MAPPINGS_PERMIT = 0x0001;
-    pub const WX_MAPPINGS_DISALLOW_EXEC = 0x0002;
-    pub const WX_MAPPINGS_ENFORCE = 0x80000000;
-    pub const PROCCTL_MD_MIN = 0x10000000;
-    // x86_64-only constants
-    pub const KPTI = switch (builtin.cpu.arch) {
-        .x86_64 => struct {
-            pub const CTL = PROC.PROCCTL_MD_MIN;
-            pub const STATUS = PROC.PROCCTL_MD_MIN + 1;
-            pub const CTL_ENABLE_ON_EXEC = 1;
-            pub const CTL_DISABLE_ON_EXEC = 2;
-            pub const STATUS_ACTIVE = 0x80000000;
-        },
-        else => void,
-    };
-    pub const LA = switch (builtin.cpu.arch) {
-        .x86_64 => struct {
-            pub const CTL = PROC.PROCCTL_MD_MIN + 2;
-            pub const STATUS = PROC.PROCCTL_MD_MIN + 3;
-            pub const CTL_LA48_ON_EXEC = 1;
-            pub const CTL_LA57_ON_EXEC = 2;
-            pub const CTL_DEFAULT_ON_EXEC = 3;
-            pub const STATUS_LA48 = 0x01000000;
-            pub const STATUS_LA57 = 0x02000000;
-        },
-        else => void,
-    };
-};
-
-pub const PPROT = struct {
-    pub fn OP(x: i32) i32 {
-        return x & 0xf;
-    }
-    pub const SET = 1;
-    pub const CLEAR = 2;
-    pub fn FLAGS(x: i32) i32 {
-        return x & !0xf;
-    }
-    pub const DESCEND = 0x10;
-    pub const INHERIT = 0x20;
-};
-
-pub const REAPER = struct {
-    pub const STATUS_OWNED = 0x00000001;
-    pub const STATUS_REALINIT = 0x00000002;
-    pub const PIDINFO_VALID = 0x00000001;
-    pub const PIDINFO_CHILD = 0x00000002;
-    pub const PIDINFO_REAPER = 0x00000004;
-    pub const KILL_CHILDREN = 0x00000001;
-    pub const KILL_SUBTREE = 0x00000002;
-};
-
-pub const procctl_reaper_status = extern struct {
-    rs_flags: u32,
-    rs_children: u32,
-    rs_descendants: u32,
-    rs_reaper: pid_t,
-    rs_pid: pid_t,
-    rs_pad0: [15]u32,
-};
-
-pub const procctl_reaper_pidinfo = extern struct {
-    pi_pid: pid_t,
-    pi_subtree: pid_t,
-    pi_flags: u32,
-    pi_pad0: [15]u32,
-};
-
-pub const procctl_reaper_pids = extern struct {
-    rp_count: u32,
-    rp_pad0: [15]u32,
-    rp_pids: [*]procctl_reaper_pidinfo,
-};
-
-pub const procctl_reaper_kill = extern struct {
-    rk_sig: c_int,
-    rk_flags: u32,
-    rk_subtree: pid_t,
-    rk_killed: u32,
-    rk_fpid: pid_t,
-    rk_pad0: [15]u32,
-};
-
-pub extern "c" fn procctl(idtype: idtype_t, id: id_t, cmd: c_int, data: ?*anyopaque) c_int;
-
-pub const SHM = struct {
-    pub const ALLOW_SEALING = 0x00000001;
-    pub const GROW_ON_WRWITE = 0x00000002;
-    pub const LARGEPAGE = 0x00000004;
-    pub const LARGEPAGE_ALLOC_DEFAULT = 0;
-    pub const LARGEPAGE_ALLOC_NOWAIT = 1;
-    pub const LARGEPAGE_ALLOC_HARD = 2;
-};
-
-pub const shm_largeconf = extern struct {
-    psind: c_int,
-    alloc_policy: c_int,
-    pad: [10]c_int,
-};
-
-pub extern "c" fn shm_create_largepage(path: [*:0]const u8, flags: c_int, psind: c_int, alloc_policy: c_int, mode: mode_t) c_int;
-
-pub extern "c" fn elf_aux_info(aux: c_int, buf: ?*anyopaque, buflen: c_int) c_int;
-
-pub const lwpid = i32;
-
-pub const SIGEV = struct {
-    pub const NONE = 0;
-    pub const SIGNAL = 1;
-    pub const THREAD = 2;
-    pub const KEVENT = 3;
-    pub const THREAD_ID = 4;
-};
-
-pub const sigevent = extern struct {
-    sigev_notify: c_int,
-    sigev_signo: c_int,
-    sigev_value: sigval,
-    _sigev_un: extern union {
-        _threadid: lwpid,
-        _sigev_thread: extern struct {
-            _function: ?*const fn (sigval) callconv(.C) void,
-            _attribute: ?**pthread_attr_t,
-        },
-        _kevent_flags: c_ushort,
-        __spare__: [8]c_long,
-    },
-};
-
-pub const timer_t = *opaque {};
-
-pub const MIN = struct {
-    pub const INCORE = 0x1;
-    pub const REFERENCED = 0x2;
-    pub const MODIFIED = 0x4;
-    pub const REFERENCED_OTHER = 0x8;
-    pub const MODIFIED_OTHER = 0x10;
-    pub const SUPER = 0x60;
-    pub fn PSIND(i: u32) u32 {
-        return (i << 5) & SUPER;
-    }
-};
-
-pub extern "c" fn mincore(
-    addr: *align(std.mem.page_size) const anyopaque,
-    length: usize,
-    vec: [*]u8,
-) c_int;
-
-pub const MAXMEMDOM = 8;
-pub const domainid_t = u8;
-
-pub const LIST_ENTRY = opaque {};
-
-pub const DOMAINSET = struct {
-    pub const POLICY_INVALID = 0;
-    pub const POLICY_ROUNDROBIN = 1;
-    pub const POLICY_FIRSTOUCH = 2;
-    pub const POLICY_PREFER = 3;
-    pub const POLICY_INTERLEAVE = 4;
-    pub const POLICY_MAX = DOMAINSET.POLICY_INTERLEAVE;
-};
-
-pub const DOMAINSET_SIZE = 256;
-pub const domainset_t = extern struct {
-    __bits: [(DOMAINSET_SIZE + (@sizeOf(domainset) - 1)) / @bitSizeOf(domainset)]domainset,
-};
-
-pub fn DOMAINSET_COUNT(set: domainset_t) c_int {
-    return @as(c_int, @intCast(__BIT_COUNT(set.__bits[0..])));
-}
-
-pub const domainset = extern struct {
-    link: LIST_ENTRY,
-    mask: domainset_t,
-    policy: u16,
-    prefer: domainid_t,
-    cnt: domainid_t,
-    order: [MAXMEMDOM]domainid_t,
-};
-
-pub extern "c" fn cpuset_getdomain(level: cpulevel_t, which: cpuwhich_t, id: id_t, len: usize, domain: *domainset_t, r: *c_int) c_int;
-pub extern "c" fn cpuset_setdomain(level: cpulevel_t, which: cpuwhich_t, id: id_t, len: usize, domain: *const domainset_t, r: c_int) c_int;
-
-const ioctl_cmd = enum(u32) {
-    VOID = 0x20000000,
-    OUT = 0x40000000,
-    IN = 0x80000000,
-    INOUT = ioctl_cmd.IN | ioctl_cmd.OUT,
-    DIRMASK = ioctl_cmd.VOID | ioctl_cmd.IN | ioctl_cmd.OUT,
-};
-
-fn ioImpl(cmd: ioctl_cmd, op: u8, nr: u8, comptime IT: type) u32 {
-    return @as(u32, @bitCast(@intFromEnum(cmd) | @as(u32, @intCast(@as(u8, @truncate(@sizeOf(IT))))) << 16 | @as(u32, @intCast(op)) << 8 | nr));
-}
-
-pub fn IO(op: u8, nr: u8) u32 {
-    return ioImpl(ioctl_cmd.VOID, op, nr, 0);
-}
-
-pub fn IOR(op: u8, nr: u8, comptime IT: type) u32 {
-    return ioImpl(ioctl_cmd.OUT, op, nr, @sizeOf(IT));
-}
-
-pub fn IOW(op: u8, nr: u8, comptime IT: type) u32 {
-    return ioImpl(ioctl_cmd.IN, op, nr, @sizeOf(IT));
-}
-
-pub fn IOWR(op: u8, nr: u8, comptime IT: type) u32 {
-    return ioImpl(ioctl_cmd.INOUT, op, nr, @sizeOf(IT));
-}
-
-pub const RF = struct {
-    pub const NAMEG = 1 << 0;
-    pub const ENVG = 1 << 1;
-    /// copy file descriptors table
-    pub const FDG = 1 << 2;
-    pub const NOTEG = 1 << 3;
-    /// creates a new process
-    pub const PROC = 1 << 4;
-    /// shares address space
-    pub const MEM = 1 << 5;
-    /// detaches the child
-    pub const NOWAIT = 1 << 6;
-    pub const CNAMEG = 1 << 10;
-    pub const CENVG = 1 << 11;
-    /// distinct file descriptor table
-    pub const CFDG = 1 << 12;
-    /// thread support
-    pub const THREAD = 1 << 13;
-    /// shares signal handlers
-    pub const SIGSHARE = 1 << 14;
-    /// emits SIGUSR1 on exit
-    pub const LINUXTHPN = 1 << 16;
-    /// child in stopped state
-    pub const STOPPED = 1 << 17;
-    /// use high pid id
-    pub const HIGHPID = 1 << 18;
-    /// selects signal flag for parent notification
-    pub const SIGSZMB = 1 << 19;
-    pub fn SIGNUM(f: u32) u32 {
-        return f >> 20;
-    }
-    pub fn SIGFLAGS(f: u32) u32 {
-        return f << 20;
-    }
-};
-
-pub extern "c" fn rfork(flags: c_int) c_int;
-
-pub const PTRACE = struct {
-    pub const EXC = 0x0001;
-    pub const SCE = 0x0002;
-    pub const SCX = 0x0004;
-    pub const SYSCALL = (PTRACE.SCE | PTRACE.SCX);
-    pub const FORK = 0x0008;
-    pub const LWP = 0x0010;
-    pub const VFORK = 0x0020;
-    pub const DEFAULT = PTRACE.EXEC;
-};
-
-pub const PT = struct {
-    pub const TRACE_ME = 0;
-    pub const READ_I = 1;
-    pub const READ_D = 2;
-    pub const WRITE_I = 4;
-    pub const WRITE_D = 5;
-    pub const CONTINUE = 7;
-    pub const KILL = 8;
-    pub const STEP = 9;
-    pub const ATTACH = 10;
-    pub const DETACH = 11;
-    pub const IO = 12;
-    pub const LWPINFO = 13;
-    pub const GETNUMLWPS = 14;
-    pub const GETLWPLIST = 15;
-    pub const CLEARSTEP = 16;
-    pub const SETSTEP = 17;
-    pub const SUSPEND = 18;
-    pub const RESUME = 19;
-    pub const TO_SCE = 20;
-    pub const TO_SCX = 21;
-    pub const SYSCALL = 22;
-    pub const FOLLOW_FORK = 23;
-    pub const LWP_EVENTS = 24;
-    pub const GET_EVENT_MASK = 25;
-    pub const SET_EVENT_MASK = 26;
-    pub const GET_SC_ARGS = 27;
-    pub const GET_SC_RET = 28;
-    pub const COREDUMP = 29;
-    pub const GETREGS = 33;
-    pub const SETREGS = 34;
-    pub const GETFPREGS = 35;
-    pub const SETFPREGS = 36;
-    pub const GETDBREGS = 37;
-    pub const SETDBREGS = 38;
-    pub const VM_TIMESTAMP = 40;
-    pub const VM_ENTRY = 41;
-    pub const GETREGSET = 42;
-    pub const SETREGSET = 43;
-    pub const SC_REMOTE = 44;
-    pub const FIRSTMACH = 64;
-};
-
-pub const ptrace_io_desc = extern struct {
-    op: c_int,
-    offs: ?*anyopaque,
-    addr: ?*anyopaque,
-    len: usize,
-};
-
-pub const PIOD = struct {
-    pub const READ_D = 1;
-    pub const WRITE_D = 2;
-    pub const READ_I = 3;
-    pub const WRITE_I = 4;
-};
-
-pub const ptrace_lwpinfo = extern struct {
-    lwpid: lwpid_t,
-    event: c_int,
-    flags: c_int,
-    sigmask: sigset_t,
-    siglist: sigset_t,
-    siginfo: siginfo_t,
-    tdname: [MAXCOMLEN + 1]u8,
-    child_pid: pid_t,
-    syscall_code: c_uint,
-    syscall_narg: c_uint,
-};
-
-pub const ptrace_sc_ret = extern struct {
-    retval: [2]isize,
-    err: c_int,
-};
-
-pub const ptrace_vm_entry = extern struct {
-    entry: c_int,
-    timestamp: c_int,
-    start: c_ulong,
-    end: c_ulong,
-    offset: c_ulong,
-    prot: c_uint,
-    pathlen: c_uint,
-    fileid: c_long,
-    fsid: u32,
-    pve_path: ?[*:0]u8,
-};
-
-pub const ptrace_coredump = extern struct {
-    fd: c_int,
-    flags: u32,
-    limit: isize,
-};
-
-pub const ptrace_cs_remote = extern struct {
-    ret: ptrace_sc_ret,
-    syscall: c_uint,
-    nargs: c_uint,
-    args: *isize,
-};
-
-pub extern "c" fn ptrace(request: c_int, pid: pid_t, addr: [*:0]u8, data: c_int) c_int;
-
-/// TODO refines if necessary
-pub const PTHREAD_STACK_MIN = switch (builtin.cpu.arch) {
-    .x86, .powerpc => 4 * 512,
-    else => 4 * 1024,
-};
-
-pub const SYS_NMLN = 256;
-
-pub const utsname = extern struct {
-    sysname: [255:0]u8,
-    nodename: [255:0]u8,
-    release: [255:0]u8,
-    version: [255:0]u8,
-    machine: [255:0]u8,
-};
-
-pub extern "c" fn uname(u: *utsname) c_int;
diff --git a/lib/std/c/haiku.zig b/lib/std/c/haiku.zig
index d75bcbdc33a4..a64eb03b419f 100644
--- a/lib/std/c/haiku.zig
+++ b/lib/std/c/haiku.zig
@@ -5,15 +5,11 @@ const maxInt = std.math.maxInt;
 const iovec = std.os.iovec;
 const iovec_const = std.os.iovec_const;
 
-const status_t = i32;
-
 extern "c" fn _errnop() *c_int;
 
 pub const _errno = _errnop;
 
-pub extern "c" fn find_directory(which: directory_which, volume: i32, createIt: bool, path_ptr: [*]u8, length: i32) status_t;
-
-pub extern "c" fn find_path(codePointer: ?*const u8, baseDirectory: path_base_directory, subPath: ?[*:0]const u8, pathBuffer: [*:0]u8, bufferSize: usize) status_t;
+pub extern "c" fn find_directory(which: c_int, volume: i32, createIt: bool, path_ptr: [*]u8, length: i32) u64;
 
 pub extern "c" fn find_thread(thread_name: ?*anyopaque) i32;
 
@@ -173,25 +169,25 @@ pub const Flock = extern struct {
 
 pub const msghdr = extern struct {
     /// optional address
-    name: ?*sockaddr,
+    msg_name: ?*sockaddr,
 
     /// size of address
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
 
     /// scatter/gather array
-    iov: [*]iovec,
+    msg_iov: [*]iovec,
 
     /// # elements in msg_iov
-    iovlen: i32,
+    msg_iovlen: i32,
 
     /// ancillary data
-    control: ?*anyopaque,
+    msg_control: ?*anyopaque,
 
     /// ancillary data buffer len
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
 
     /// flags on received message
-    flags: i32,
+    msg_flags: i32,
 };
 
 pub const off_t = i64;
@@ -1024,13 +1020,6 @@ pub const directory_which = enum(c_int) {
     _,
 };
 
-// TODO fill out if needed
-pub const path_base_directory = enum(c_int) {
-    B_FIND_PATH_IMAGE_PATH = 1000,
-};
-
-pub const B_APP_IMAGE_SYMBOL = null;
-
 pub const cc_t = u8;
 pub const speed_t = u8;
 pub const tcflag_t = u32;
@@ -1049,27 +1038,3 @@ pub const termios = extern struct {
 };
 
 pub const MSG_NOSIGNAL = 0x0800;
-
-pub const SIGEV = struct {
-    pub const NONE = 0;
-    pub const SIGNAL = 1;
-    pub const THREAD = 2;
-};
-
-pub const sigval = extern union {
-    int: c_int,
-    ptr: ?*anyopaque,
-};
-
-pub const sigevent = extern struct {
-    sigev_notify: c_int,
-    sigev_signo: c_int,
-    sigev_value: sigval,
-    sigev_notify_function: ?*const fn (sigval) callconv(.C) void,
-    sigev_notify_attributes: ?*pthread_attr_t,
-};
-
-/// TODO refines if necessary
-pub const PTHREAD_STACK_MIN = 2 * 4096;
-
-pub extern "c" fn malloc_usable_size(?*anyopaque) usize;
diff --git a/lib/std/c/linux.zig b/lib/std/c/linux.zig
index ddc488e11521..c4986101dfad 100644
--- a/lib/std/c/linux.zig
+++ b/lib/std/c/linux.zig
@@ -13,10 +13,6 @@ pub const ARCH = linux.ARCH;
 pub const AT = linux.AT;
 pub const CLOCK = linux.CLOCK;
 pub const CPU_COUNT = linux.CPU_COUNT;
-pub const CPU_SET = linux.CPU_SET;
-pub const CPU_ISSET = linux.CPU_ISSET;
-pub const CPU_CLR = linux.CPU_CLR;
-pub const CPU_ZERO = linux.CPU_ZERO;
 pub const E = linux.E;
 pub const Elf_Symndx = linux.Elf_Symndx;
 pub const F = linux.F;
@@ -100,7 +96,6 @@ pub const stack_t = linux.stack_t;
 pub const tcflag_t = linux.tcflag_t;
 pub const termios = linux.termios;
 pub const time_t = linux.time_t;
-pub const timer_t = linux.timer_t;
 pub const timespec = linux.timespec;
 pub const timeval = linux.timeval;
 pub const timezone = linux.timezone;
@@ -250,7 +245,6 @@ pub extern "c" fn setrlimit64(resource: rlimit_resource, rlim: *const rlimit) c_
 
 pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize;
 pub extern "c" fn sched_getaffinity(pid: c_int, size: usize, set: *cpu_set_t) c_int;
-pub extern "c" fn sched_setaffinity(pid: c_int, size: usize, set: *const cpu_set_t) c_int;
 pub extern "c" fn eventfd(initval: c_uint, flags: c_uint) c_int;
 pub extern "c" fn epoll_ctl(epfd: fd_t, op: c_uint, fd: fd_t, event: ?*epoll_event) c_int;
 pub extern "c" fn epoll_create1(flags: c_uint) c_int;
@@ -351,18 +345,6 @@ const __SIZEOF_PTHREAD_MUTEX_T = switch (native_abi) {
 };
 const __SIZEOF_SEM_T = 4 * @sizeOf(usize);
 
-/// TODO refines if necessary
-pub const PTHREAD_STACK_MIN = switch (native_abi) {
-    .musl, .musleabi, .musleabihf => 2048,
-    .gnu, .gnuabin32, .gnuabi64, .gnueabi, .gnueabihf, .gnux32 => switch (native_arch) {
-        .aarch64, .arm, .armeb, .powerpc, .powerpc64, .powerpc64le, .loongarch32, .loongarch64 => 131072,
-        .sparc64 => 24576,
-        else => 16 * 1024,
-    },
-    .android => if (@sizeOf(usize) == 8) 16 * 1024 else 8 * 1024,
-    else => 16 * 1024,
-};
-
 pub extern "c" fn pthread_setname_np(thread: std.c.pthread_t, name: [*:0]const u8) E;
 pub extern "c" fn pthread_getname_np(thread: std.c.pthread_t, name: [*:0]u8, len: usize) E;
 
@@ -389,19 +371,3 @@ pub const dirent64 = struct {
     d_type: u8,
     d_name: [256]u8,
 };
-
-pub const MPOL = struct {
-    pub const F_NODE = 1 << 0;
-    pub const F_ADDR = 1 << 1;
-    pub const F_MEMS_ALLOWED = 1 << 2;
-    /// flags for SYS_mbind
-    pub const MF_STRICT = 1 << 0;
-    pub const MF_MOVE = 1 << 1;
-    pub const MF_MOVE_ALL = 1 << 2;
-    pub const MF_LAZY = 1 << 3;
-    pub const MF_INTERNAL = 1 << 4;
-    pub const MF_VALID = MPOL.MF_STRICT | MPOL.MF_MOVE | MPOL.MOVE_ALL;
-};
-
-pub extern "c" fn getcpu(cpu: *c_uint, node: *c_uint) c_int;
-pub extern "c" fn sched_getcpu() c_int;
diff --git a/lib/std/c/minix.zig b/lib/std/c/minix.zig
index 672f36ca86f1..62cefc14fb57 100644
--- a/lib/std/c/minix.zig
+++ b/lib/std/c/minix.zig
@@ -16,5 +16,3 @@ const __SIZEOF_PTHREAD_MUTEX_T = switch (builtin.abi) {
     },
     else => unreachable,
 };
-
-pub const PTHREAD_STACK_MIN = 16 * 1024;
diff --git a/lib/std/c/netbsd.zig b/lib/std/c/netbsd.zig
index 3ab33cf9d528..4b627ed083b7 100644
--- a/lib/std/c/netbsd.zig
+++ b/lib/std/c/netbsd.zig
@@ -121,21 +121,9 @@ pub const pthread_attr_t = extern struct {
 };
 
 pub const sem_t = ?*opaque {};
-pub const cpuset_t = opaque {};
-pub const cpuid_t = c_ulong;
 
 pub extern "c" fn pthread_setname_np(thread: std.c.pthread_t, name: [*:0]const u8, arg: ?*anyopaque) E;
 pub extern "c" fn pthread_getname_np(thread: std.c.pthread_t, name: [*:0]u8, len: usize) E;
-pub extern "c" fn pthread_setaffinity_np(thread: std.c.pthread_t, size: usize, set: ?*cpuset_t) c_int;
-pub extern "c" fn pthread_getaffinity_np(thread: std.c.pthread_t, size: usize, set: ?*cpuset_t) c_int;
-
-pub extern "c" fn cpuset_create() ?*cpuset_t;
-pub extern "c" fn cpuset_destroy(set: ?*cpuset_t) void;
-pub extern "c" fn cpuset_zero(set: ?*cpuset_t) void;
-pub extern "c" fn cpuset_set(cpu: cpuid_t, set: ?*cpuset_t) c_int;
-pub extern "c" fn cpuset_clr(cpu: cpuid_t, set: ?*cpuset_t) c_int;
-pub extern "c" fn cpuset_isset(cpu: cpuid_t, set: ?*const cpuset_t) c_int;
-pub extern "c" fn cpuset_size(set: ?*cpuset_t) usize;
 
 pub const blkcnt_t = i64;
 pub const blksize_t = i32;
@@ -253,48 +241,48 @@ pub const EAI_MAX = 15;
 
 pub const msghdr = extern struct {
     /// optional address
-    name: ?*sockaddr,
+    msg_name: ?*sockaddr,
 
     /// size of address
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
 
     /// scatter/gather array
-    iov: [*]iovec,
+    msg_iov: [*]iovec,
 
     /// # elements in msg_iov
-    iovlen: i32,
+    msg_iovlen: i32,
 
     /// ancillary data
-    control: ?*anyopaque,
+    msg_control: ?*anyopaque,
 
     /// ancillary data buffer len
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
 
     /// flags on received message
-    flags: i32,
+    msg_flags: i32,
 };
 
 pub const msghdr_const = extern struct {
     /// optional address
-    name: ?*const sockaddr,
+    msg_name: ?*const sockaddr,
 
     /// size of address
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
 
     /// scatter/gather array
-    iov: [*]const iovec_const,
+    msg_iov: [*]const iovec_const,
 
     /// # elements in msg_iov
-    iovlen: i32,
+    msg_iovlen: i32,
 
     /// ancillary data
-    control: ?*const anyopaque,
+    msg_control: ?*const anyopaque,
 
     /// ancillary data buffer len
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
 
     /// flags on received message
-    flags: i32,
+    msg_flags: i32,
 };
 
 /// The stat structure used by libc.
@@ -485,11 +473,6 @@ pub const AF = struct {
     pub const MAX = 37;
 };
 
-pub const accept_filter_arg = extern struct {
-    af_name: [16]u8,
-    af_args: [240]u8,
-};
-
 pub const in_port_t = u16;
 pub const sa_family_t = u8;
 
@@ -579,12 +562,6 @@ pub const PROT = struct {
     pub const READ = 1;
     pub const WRITE = 2;
     pub const EXEC = 4;
-    pub fn MPROTECT(flag: u32) u32 {
-        return flag << 3;
-    }
-    pub fn MPROTECT_EXTRACT(flag: u32) u32 {
-        return (flag >> 3) & 0x7;
-    }
 };
 
 pub const CLOCK = struct {
@@ -614,27 +591,6 @@ pub const MAP = struct {
     pub const ANON = 0x1000;
     pub const ANONYMOUS = ANON;
     pub const STACK = 0x2000;
-
-    pub const ALIGNMENT_SHIFT = 24;
-    pub fn ALIGNED(n: u32) u32 {
-        return n << ALIGNMENT_SHIFT;
-    }
-    pub const ALIGNMENT_64KB = MAP.ALIGNED(0xff);
-    pub const ALIGNMENT_16MB = MAP.ALIGNED(16);
-    pub const ALIGNMENT_4GB = MAP.ALIGNED(32);
-    pub const ALIGNMENT_1TB = MAP.ALIGNED(40);
-    pub const ALIGNMENT_256TB = MAP.ALIGNED(48);
-    pub const ALIGNMENT_64PB = MAP.ALIGNED(56);
-};
-
-pub const MADV = struct {
-    pub const NORMAL = 0;
-    pub const RANDOM = 1;
-    pub const SEQUENTIAL = 2;
-    pub const WILLNEED = 3;
-    pub const DONTNEED = 4;
-    pub const SPACEAVAIL = 5;
-    pub const FREE = 6;
 };
 
 pub const MSF = struct {
@@ -1665,79 +1621,3 @@ pub const POLL = struct {
     pub const HUP = 0x0010;
     pub const NVAL = 0x0020;
 };
-
-pub const SIGEV = struct {
-    pub const NONE = 0;
-    pub const SIGNAL = 1;
-    pub const THREAD = 2;
-};
-
-pub const sigval = extern union {
-    int: c_int,
-    ptr: ?*anyopaque,
-};
-
-pub const sigevent = extern struct {
-    sigev_notify: c_int,
-    sigev_signo: c_int,
-    sigev_value: sigval,
-    sigev_notify_function: ?*const fn (sigval) callconv(.C) void,
-    sigev_notify_attributes: ?*pthread_attr_t,
-};
-
-pub const PTRACE = struct {
-    pub const FORK = 0x0001;
-    pub const VFORK = 0x0002;
-    pub const VFORK_DONE = 0x0004;
-    pub const LWP_CREATE = 0x0008;
-    pub const LWP_EXIT = 0x0010;
-    pub const POSIX_SPAWN = 0x0020;
-};
-
-pub const PT = struct {
-    pub const TRACE_ME = 0;
-    pub const READ_I = 1;
-    pub const READ_D = 2;
-    pub const WRITE_I = 4;
-    pub const WRITE_D = 5;
-    pub const CONTINUE = 7;
-    pub const KILL = 8;
-    pub const ATTACH = 9;
-    pub const DETACH = 10;
-    pub const IO = 11;
-    pub const DUMPCORE = 11;
-    pub const LWPINFO = 12;
-};
-
-pub const ptrace_event = extern struct {
-    set_event: c_int,
-};
-
-pub const ptrace_state = extern struct {
-    report_event: c_int,
-    _option: extern union {
-        other_pid: pid_t,
-        lwp: lwpid_t,
-    },
-};
-
-pub const ptrace_io_desc = extern struct {
-    op: c_int,
-    offs: ?*anyopaque,
-    addr: ?*anyopaque,
-    len: usize,
-};
-
-pub const PIOD = struct {
-    pub const READ_D = 1;
-    pub const WRITE_D = 2;
-    pub const READ_I = 3;
-    pub const WRITE_I = 4;
-};
-
-pub extern "c" fn ptrace(request: c_int, pid: pid_t, addr: ?*anyopaque, data: c_int) c_int;
-
-/// TODO refines if necessary
-pub const PTHREAD_STACK_MIN = 16 * 1024;
-
-pub const timer_t = *opaque {};
diff --git a/lib/std/c/openbsd.zig b/lib/std/c/openbsd.zig
index b18978dfbb58..23478a42b450 100644
--- a/lib/std/c/openbsd.zig
+++ b/lib/std/c/openbsd.zig
@@ -251,48 +251,48 @@ pub const EAI_MAX = 15;
 
 pub const msghdr = extern struct {
     /// optional address
-    name: ?*sockaddr,
+    msg_name: ?*sockaddr,
 
     /// size of address
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
 
     /// scatter/gather array
-    iov: [*]iovec,
+    msg_iov: [*]iovec,
 
     /// # elements in msg_iov
-    iovlen: c_uint,
+    msg_iovlen: c_uint,
 
     /// ancillary data
-    control: ?*anyopaque,
+    msg_control: ?*anyopaque,
 
     /// ancillary data buffer len
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
 
     /// flags on received message
-    flags: c_int,
+    msg_flags: c_int,
 };
 
 pub const msghdr_const = extern struct {
     /// optional address
-    name: ?*const sockaddr,
+    msg_name: ?*const sockaddr,
 
     /// size of address
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
 
     /// scatter/gather array
-    iov: [*]const iovec_const,
+    msg_iov: [*]const iovec_const,
 
     /// # elements in msg_iov
-    iovlen: c_uint,
+    msg_iovlen: c_uint,
 
     /// ancillary data
-    control: ?*const anyopaque,
+    msg_control: ?*const anyopaque,
 
     /// ancillary data buffer len
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
 
     /// flags on received message
-    flags: c_int,
+    msg_flags: c_int,
 };
 
 pub const Stat = extern struct {
@@ -466,16 +466,6 @@ pub const MAP = struct {
     pub const CONCEAL = 0x8000;
 };
 
-pub const MADV = struct {
-    pub const NORMAL = 0;
-    pub const RANDOM = 1;
-    pub const SEQUENTIAL = 2;
-    pub const WILLNEED = 3;
-    pub const DONTNEED = 4;
-    pub const SPACEAVAIL = 5;
-    pub const FREE = 6;
-};
-
 pub const MSF = struct {
     pub const ASYNC = 1;
     pub const INVALIDATE = 2;
@@ -1137,18 +1127,6 @@ pub usingnamespace switch (builtin.cpu.arch) {
             sc_cookie: c_long,
         };
     },
-    .aarch64 => struct {
-        pub const ucontext_t = extern struct {
-            __sc_unused: c_int,
-            sc_mask: c_int,
-            sc_sp: c_ulong,
-            sc_lr: c_ulong,
-            sc_elr: c_ulong,
-            sc_spsr: c_ulong,
-            sc_x: [30]c_ulong,
-            sc_cookie: c_long,
-        };
-    },
     else => struct {},
 };
 
@@ -1615,39 +1593,3 @@ pub const KERN = struct {
     pub const PROC_ENV = 3;
     pub const PROC_NENV = 4;
 };
-
-pub const HW = struct {
-    pub const MACHINE = 1;
-    pub const MODEL = 2;
-    pub const NCPU = 3;
-    pub const BYTEORDER = 4;
-    pub const PHYSMEM = 5;
-    pub const USERMEM = 6;
-    pub const PAGESIZE = 7;
-    pub const DISKNAMES = 8;
-    pub const DISKSTATS = 9;
-    pub const DISKCOUNT = 10;
-    pub const SENSORS = 11;
-    pub const CPUSPEED = 12;
-    pub const SETPERF = 13;
-    pub const VENDOR = 14;
-    pub const PRODUCT = 15;
-    pub const VERSION = 16;
-    pub const SERIALNO = 17;
-    pub const UUID = 18;
-    pub const PHYSMEM64 = 19;
-    pub const USERMEM64 = 20;
-    pub const NCPUFOUND = 21;
-    pub const ALLOWPOWERDOWN = 22;
-    pub const PERFPOLICY = 23;
-    pub const SMT = 24;
-    pub const NCPUONLINE = 25;
-    pub const POWER = 26;
-};
-
-/// TODO refines if necessary
-pub const PTHREAD_STACK_MIN = switch (builtin.cpu.arch) {
-    .sparc64 => 1 << 13,
-    .mips64 => 1 << 14,
-    else => 1 << 12,
-};
diff --git a/lib/std/c/solaris.zig b/lib/std/c/solaris.zig
index d6014a7a991f..58d02416cbdb 100644
--- a/lib/std/c/solaris.zig
+++ b/lib/std/c/solaris.zig
@@ -16,7 +16,6 @@ pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) usize;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
 pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
 pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
-pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize;
 pub extern "c" fn posix_memalign(memptr: *?*anyopaque, alignment: usize, size: usize) c_int;
 pub extern "c" fn sysconf(sc: c_int) i64;
 pub extern "c" fn signalfd(fd: fd_t, mask: *const sigset_t, flags: u32) c_int;
@@ -183,36 +182,36 @@ pub const EAI_MAX = 14;
 
 pub const msghdr = extern struct {
     /// optional address
-    name: ?*sockaddr,
+    msg_name: ?*sockaddr,
     /// size of address
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
     /// scatter/gather array
-    iov: [*]iovec,
+    msg_iov: [*]iovec,
     /// # elements in msg_iov
-    iovlen: i32,
+    msg_iovlen: i32,
     /// ancillary data
-    control: ?*anyopaque,
+    msg_control: ?*anyopaque,
     /// ancillary data buffer len
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
     /// flags on received message
-    flags: i32,
+    msg_flags: i32,
 };
 
 pub const msghdr_const = extern struct {
     /// optional address
-    name: ?*const sockaddr,
+    msg_name: ?*const sockaddr,
     /// size of address
-    namelen: socklen_t,
+    msg_namelen: socklen_t,
     /// scatter/gather array
-    iov: [*]const iovec_const,
+    msg_iov: [*]const iovec_const,
     /// # elements in msg_iov
-    iovlen: i32,
+    msg_iovlen: i32,
     /// ancillary data
-    control: ?*const anyopaque,
+    msg_control: ?*const anyopaque,
     /// ancillary data buffer len
-    controllen: socklen_t,
+    msg_controllen: socklen_t,
     /// flags on received message
-    flags: i32,
+    msg_flags: i32,
 };
 
 pub const cmsghdr = extern struct {
@@ -1927,26 +1926,3 @@ pub fn IOW(io_type: u8, nr: u8, comptime IOT: type) i32 {
 pub fn IOWR(io_type: u8, nr: u8, comptime IOT: type) i32 {
     return ioImpl(.read_write, io_type, nr, IOT);
 }
-
-pub const SIGEV = struct {
-    pub const NONE = 0;
-    pub const SIGNAL = 1;
-    pub const THREAD = 2;
-};
-
-pub const sigval = extern union {
-    int: c_int,
-    ptr: ?*anyopaque,
-};
-
-pub const sigevent = extern struct {
-    sigev_notify: c_int,
-    sigev_signo: c_int,
-    sigev_value: sigval,
-    sigev_notify_function: ?*const fn (sigval) callconv(.C) void,
-    sigev_notify_attributes: ?*pthread_attr_t,
-};
-
-pub const PTHREAD_STACK_MIN = if (@sizeOf(usize) == 8) 8 * 1024 else 4 * 1024;
-
-pub const timer_t = *opaque {};
diff --git a/lib/std/c/wasi.zig b/lib/std/c/wasi.zig
index 2cb0a32b062f..e1940054b6db 100644
--- a/lib/std/c/wasi.zig
+++ b/lib/std/c/wasi.zig
@@ -119,5 +119,3 @@ pub const POLL = struct {
     pub const HUP = 0x2000;
     pub const NVAL = 0x4000;
 };
-
-pub const PTHREAD_STACK_MIN = 16 * 1024;
diff --git a/lib/std/fs.zig b/lib/std/fs.zig
index cb6ce2032ec7..a76da24713bc 100644
--- a/lib/std/fs.zig
+++ b/lib/std/fs.zig
@@ -2929,7 +2929,6 @@ pub const OpenSelfExeError = error{
     /// On Windows, file paths cannot contain these characters:
     /// '/', '*', '?', '"', '<', '>', '|'
     BadPathName,
-    Overflow,
     Unexpected,
 } || os.OpenError || SelfExePathError || os.FlockError;
 
@@ -3009,14 +3008,7 @@ pub fn selfExePath(out_buffer: []u8) SelfExePathError![]u8 {
             // TODO could this slice from 0 to out_len instead?
             return mem.sliceTo(out_buffer, 0);
         },
-        .haiku => {
-            // The only possible issue when looking for the self image path is
-            // when the buffer is too short.
-            if (os.find_path(os.B_APP_IMAGE_SYMBOL, os.path_base_directory.B_FIND_IMAGE_PATH, null, out_buffer.ptr, out_buffer.len) != 0)
-                return error.Overflow;
-            return mem.sliceTo(out_buffer, 0);
-        },
-        .openbsd => {
+        .openbsd, .haiku => {
             // OpenBSD doesn't support getting the path of a running process, so try to guess it
             if (os.argv.len == 0)
                 return error.FileNotFound;
@@ -3115,7 +3107,7 @@ const CopyFileRawError = error{SystemResources} || os.CopyFileRangeError || os.S
 // No metadata is transferred over.
 fn copy_file(fd_in: os.fd_t, fd_out: os.fd_t, maybe_size: ?u64) CopyFileRawError!void {
     if (comptime builtin.target.isDarwin()) {
-        const rc = os.system.fcopyfile(fd_in, fd_out, null, os.system.COPYFILE.DATA);
+        const rc = os.system.fcopyfile(fd_in, fd_out, null, os.system.COPYFILE_DATA);
         switch (os.errno(rc)) {
             .SUCCESS => return,
             .INVAL => unreachable,
diff --git a/lib/std/os.zig b/lib/std/os.zig
index f170eec3671e..ef167cd24a4a 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -146,12 +146,7 @@ pub const addrinfo = system.addrinfo;
 pub const blkcnt_t = system.blkcnt_t;
 pub const blksize_t = system.blksize_t;
 pub const clock_t = system.clock_t;
-pub const cpu_set_t = if (builtin.os.tag == .linux)
-    system.cpu_set_t
-else if (builtin.os.tag == .freebsd)
-    freebsd.cpuset_t
-else
-    u32;
+pub const cpu_set_t = system.cpu_set_t;
 pub const dev_t = system.dev_t;
 pub const dl_phdr_info = system.dl_phdr_info;
 pub const empty_sigset = system.empty_sigset;
@@ -517,18 +512,7 @@ pub fn getrandom(buffer: []u8) GetRandomError!void {
         return;
     }
     switch (builtin.os.tag) {
-        .macos, .ios => {
-            const rc = darwin.CCRandomGenerateBytes(buffer.ptr, buffer.len);
-            if (rc != darwin.CCRNGStatus.kCCSuccess) {
-                if (rc == darwin.CCRNGStatus.kCCParamError or rc == darwin.CCRNGStatus.kCCBufferTooSmall) {
-                    return error.InvalidHandle;
-                } else {
-                    return error.SystemResources;
-                }
-            }
-            return;
-        },
-        .netbsd, .openbsd, .tvos, .watchos => {
+        .netbsd, .openbsd, .macos, .ios, .tvos, .watchos => {
             system.arc4random_buf(buffer.ptr, buffer.len);
             return;
         },
@@ -1001,7 +985,7 @@ pub fn preadv(fd: fd_t, iov: []const iovec, offset: u64) PReadError!usize {
     if (have_pread_but_not_preadv) {
         // We could loop here; but proper usage of `preadv` must handle partial reads anyway.
         // So we simply read into the first vector only.
-        if (iov.len == 0) return @as(usize, @intCast(0));
+        if (iov.len == 0) return @as(usize, 0);
         const first = iov[0];
         return pread(fd, first.iov_base[0..first.iov_len], offset);
     }
@@ -4710,8 +4694,11 @@ pub fn sysctl(
     newp: ?*anyopaque,
     newlen: usize,
 ) SysCtlError!void {
-    if (builtin.os.tag == .wasi or builtin.os.tag == .haiku) {
-        @compileError("unsupported OS");
+    if (builtin.os.tag == .wasi) {
+        @panic("unsupported"); // TODO should be compile error, not panic
+    }
+    if (builtin.os.tag == .haiku) {
+        @panic("unsupported"); // TODO should be compile error, not panic
     }
 
     const name_len = math.cast(c_uint, name.len) orelse return error.NameTooLong;
@@ -4732,8 +4719,11 @@ pub fn sysctlbynameZ(
     newp: ?*anyopaque,
     newlen: usize,
 ) SysCtlError!void {
-    if (builtin.os.tag == .wasi or builtin.os.tag == .haiku) {
-        @compileError("unsupported OS");
+    if (builtin.os.tag == .wasi) {
+        @panic("unsupported"); // TODO should be compile error, not panic
+    }
+    if (builtin.os.tag == .haiku) {
+        @panic("unsupported"); // TODO should be compile error, not panic
     }
 
     switch (errno(system.sysctlbyname(name, oldp, oldlenp, newp, newlen))) {
@@ -5494,64 +5484,16 @@ pub fn clock_getres(clk_id: i32, res: *timespec) ClockGetTimeError!void {
 }
 
 pub const SchedGetAffinityError = error{PermissionDenied} || UnexpectedError;
-pub const SchedSetAffinityError = error{ InvalidCpu, PermissionDenied } || UnexpectedError;
 
 pub fn sched_getaffinity(pid: pid_t) SchedGetAffinityError!cpu_set_t {
     var set: cpu_set_t = undefined;
-    if (builtin.os.tag == .linux) {
-        switch (errno(system.sched_getaffinity(pid, @sizeOf(cpu_set_t), &set))) {
-            .SUCCESS => return set,
-            .FAULT => unreachable,
-            .INVAL => unreachable,
-            .SRCH => unreachable,
-            .PERM => return error.PermissionDenied,
-            else => |err| return unexpectedErrno(err),
-        }
-    } else if (builtin.os.tag == .freebsd) {
-        switch (errno(freebsd.cpuset_getaffinity(freebsd.CPU_LEVEL_WHICH, freebsd.CPU_WHICH_PID, pid, @sizeOf(cpu_set_t), &set))) {
-            .SUCCESS => return set,
-            .FAULT => unreachable,
-            .INVAL => unreachable,
-            .SRCH => unreachable,
-            .EDEADLK => unreachable,
-            .PERM => return error.PermissionDenied,
-            else => |err| return unexpectedErrno(err),
-        }
-    } else {
-        @compileError("unsupported platform");
-    }
-}
-
-pub fn sched_setaffinity(pid: pid_t, cpus: []usize) SchedSetAffinityError!cpu_set_t {
-    var set: cpu_set_t = undefined;
-    if (builtin.os.tag == .linux) {
-        system.CPU_ZERO(&set);
-        for (cpus) |cpu| {
-            system.CPU_SET(cpu, &set);
-        }
-        switch (errno(system.sched_setaffinity(pid, @sizeOf(cpu_set_t), &set))) {
-            .SUCCESS => return set,
-            .FAULT => unreachable,
-            .SRCH => unreachable,
-            .INVAL => return error.InvalidCpu,
-            .PERM => return error.PermissionDenied,
-            else => |err| return unexpectedErrno(err),
-        }
-    } else if (builtin.os.tag == .freebsd) {
-        freebsd.CPU_ZERO(&set);
-        for (cpus) |cpu| {
-            freebsd.CPU_SET(cpu, &set);
-        }
-        switch (errno(freebsd.cpuset_setaffinity(freebsd.CPU_LEVEL_WHICH, freebsd.CPU_WHICH_PID, pid, @sizeOf(cpu_set_t), &set))) {
-            .SUCCESS => return set,
-            .FAULT => unreachable,
-            .SRCH => unreachable,
-            .INVAL => return error.InvalidCpu,
-            .PERM => return error.PermissionDenied,
-            else => |err| return unexpectedErrno(err),
-        }
-    } else {
-        @compileError("unsupported platform");
+    switch (errno(system.sched_getaffinity(pid, @sizeOf(cpu_set_t), &set))) {
+        .SUCCESS => return set,
+        .FAULT => unreachable,
+        .INVAL => unreachable,
+        .SRCH => unreachable,
+        .PERM => return error.PermissionDenied,
+        else => |err| return unexpectedErrno(err),
     }
 }
 
@@ -5695,7 +5637,7 @@ pub fn gethostname(name_buffer: *[HOST_NAME_MAX]u8) GetHostNameError![]u8 {
             else => |err| return unexpectedErrno(err),
         }
     }
-    if (builtin.os.tag == .linux or builtin.os.tag == .macos or builtin.os.tag == .freebsd) {
+    if (builtin.os.tag == .linux) {
         const uts = uname();
         const hostname = mem.sliceTo(&uts.nodename, 0);
         const result = name_buffer[0..hostname.len];
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 6362e9ece1a4..f116fc0dd8e5 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -1519,28 +1519,6 @@ pub fn sched_getaffinity(pid: pid_t, size: usize, set: *cpu_set_t) usize {
     return 0;
 }
 
-pub fn getcpu(cpu: *u32, node: *u32) usize {
-    return syscall3(.getcpu, @intFromPtr(cpu), @intFromPtr(node), 0);
-}
-
-pub fn sched_getcpu() usize {
-    var cpu: u32 = undefined;
-    const rc = syscall3(.getcpu, @intFromPtr(&cpu), 0, 0);
-    if (@as(isize, @bitCast(rc)) < 0) return rc;
-    return @as(usize, @intCast(cpu));
-}
-
-/// libc has no wrapper for this syscall
-pub fn mbind(addr: ?*anyopaque, len: u32, mode: i32, nodemask: *const u32, maxnode: u32, flags: u32) usize {
-    return syscall6(.mbind, @intFromPtr(addr), len, @as(usize, @bitCast(@as(isize, mode))), @intFromPtr(nodemask), maxnode, flags);
-}
-
-pub fn sched_setaffinity(pid: pid_t, size: usize, set: *const cpu_set_t) usize {
-    const rc = syscall3(.sched_setaffinity, @as(usize, @bitCast(@as(isize, pid))), size, @intFromPtr(set));
-    if (@as(isize, @bitCast(rc)) < 0) return rc;
-    return 0;
-}
-
 pub fn epoll_create() usize {
     return epoll_create1(0);
 }
@@ -3596,11 +3574,6 @@ pub const CPU_SETSIZE = 128;
 pub const cpu_set_t = [CPU_SETSIZE / @sizeOf(usize)]usize;
 pub const cpu_count_t = std.meta.Int(.unsigned, std.math.log2(CPU_SETSIZE * 8));
 
-fn cpu_mask(s: usize) cpu_count_t {
-    var x = s & (CPU_SETSIZE * 8);
-    return @as(cpu_count_t, @intCast(1)) << @as(u4, @intCast(x));
-}
-
 pub fn CPU_COUNT(set: cpu_set_t) cpu_count_t {
     var sum: cpu_count_t = 0;
     for (set) |x| {
@@ -3609,32 +3582,6 @@ pub fn CPU_COUNT(set: cpu_set_t) cpu_count_t {
     return sum;
 }
 
-pub fn CPU_ZERO(set: *cpu_set_t) void {
-    @memset(set, 0);
-}
-
-pub fn CPU_SET(cpu: usize, set: *cpu_set_t) void {
-    const x = cpu / @sizeOf(usize);
-    if (x < @sizeOf(cpu_set_t)) {
-        (set.*)[x] |= cpu_mask(x);
-    }
-}
-
-pub fn CPU_ISSET(cpu: usize, set: cpu_set_t) bool {
-    const x = cpu / @sizeOf(usize);
-    if (x < @sizeOf(cpu_set_t)) {
-        return set[x] & cpu_mask(x) != 0;
-    }
-    return false;
-}
-
-pub fn CPU_CLR(cpu: usize, set: *cpu_set_t) void {
-    const x = cpu / @sizeOf(usize);
-    if (x < @sizeOf(cpu_set_t)) {
-        (set.*)[x] &= !cpu_mask(x);
-    }
-}
-
 pub const MINSIGSTKSZ = switch (native_arch) {
     .x86, .x86_64, .arm, .mipsel => 2048,
     .aarch64 => 5120,
diff --git a/lib/std/process.zig b/lib/std/process.zig
index 28d4bfcb25c0..eef96b46d273 100644
--- a/lib/std/process.zig
+++ b/lib/std/process.zig
@@ -1163,37 +1163,6 @@ pub fn totalSystemMemory() TotalSystemMemoryError!usize {
         .linux => {
             return totalSystemMemoryLinux() catch return error.UnknownTotalSystemMemory;
         },
-        .freebsd, .netbsd, .dragonfly, .macos => {
-            var physmem: c_ulong = undefined;
-            var len: usize = @sizeOf(c_ulong);
-            const name = switch (builtin.os.tag) {
-                .macos => "hw.memsize",
-                .netbsd => "hw.physmem64",
-                else => "hw.physmem",
-            };
-            os.sysctlbynameZ(name, &physmem, &len, null, 0) catch |err| switch (err) {
-                error.NameTooLong, error.UnknownName => unreachable,
-                else => return error.UnknownTotalSystemMemory,
-            };
-            return @as(usize, @intCast(physmem));
-        },
-        .openbsd => {
-            const mib: [2]c_int = [_]c_int{
-                std.os.CTL.HW,
-                std.os.HW.PHYSMEM64,
-            };
-            var physmem: i64 = undefined;
-            var len: usize = @sizeOf(@TypeOf(physmem));
-            std.os.sysctl(&mib, &physmem, &len, null, 0) catch |err| switch (err) {
-                error.NameTooLong => unreachable, // constant, known good value
-                error.PermissionDenied => unreachable, // only when setting values,
-                error.SystemResources => unreachable, // memory already on the stack
-                error.UnknownName => unreachable, // constant, known good value
-                else => return error.UnknownTotalSystemMemory,
-            };
-            assert(physmem >= 0);
-            return @as(usize, @bitCast(physmem));
-        },
         .windows => {
             var sbi: std.os.windows.SYSTEM_BASIC_INFORMATION = undefined;
             const rc = std.os.windows.ntdll.NtQuerySystemInformation(