Merge pull request #13935 from ziglang/mach-tasks

darwin: expose more Mach primitives, expose wrapped ptrace, and allow starting suspended for posix_spawn

7 files changed, 690 insertions, 6 deletions

diff --git a/lib/std/c/darwin.zig b/lib/std/c/darwin.zig
index 5c0338af80..b68f04379f 100644
--- a/lib/std/c/darwin.zig
+++ b/lib/std/c/darwin.zig
@@ -15,6 +15,131 @@ const arch_bits = switch (native_arch) {
     else => struct {},
 };
 
+pub const EXC_TYPES_COUNT = arch_bits.EXC_TYPES_COUNT;
+pub const THREAD_STATE_NONE = arch_bits.THREAD_STATE_NONE;
+
+pub const EXC = enum(exception_type_t) {
+    NULL = 0,
+    /// Could not access memory
+    BAD_ACCESS = 1,
+    /// Instruction failed
+    BAD_INSTRUCTION = 2,
+    /// Arithmetic exception
+    ARITHMETIC = 3,
+    /// Emulation instruction
+    EMULATION = 4,
+    /// Software generated exception
+    SOFTWARE = 5,
+    /// Trace, breakpoint, etc.
+    BREAKPOINT = 6,
+    /// System calls.
+    SYSCALL = 7,
+    /// Mach system calls.
+    MACH_SYSCALL = 8,
+    /// RPC alert
+    RPC_ALERT = 9,
+    /// Abnormal process exit
+    CRASH = 10,
+    /// Hit resource consumption limit
+    RESOURCE = 11,
+    /// Violated guarded resource protections
+    GUARD = 12,
+    /// Abnormal process exited to corpse state
+    CORPSE_NOTIFY = 13,
+};
+
+pub const EXC_SOFT_SIGNAL = 0x10003;
+
+pub const EXC_MASK_BAD_ACCESS = 1 << @enumToInt(EXC.BAD_ACCESS);
+pub const EXC_MASK_BAD_INSTRUCTION = 1 << @enumToInt(EXC.BAD_INSTRUCTION);
+pub const EXC_MASK_ARITHMETIC = 1 << @enumToInt(EXC.ARITHMETIC);
+pub const EXC_MASK_EMULATION = 1 << @enumToInt(EXC.EMULATION);
+pub const EXC_MASK_SOFTWARE = 1 << @enumToInt(EXC.SOFTWARE);
+pub const EXC_MASK_BREAKPOINT = 1 << @enumToInt(EXC.BREAKPOINT);
+pub const EXC_MASK_SYSCALL = 1 << @enumToInt(EXC.SYSCALL);
+pub const EXC_MASK_MACH_SYSCALL = 1 << @enumToInt(EXC.MACH_SYSCALL);
+pub const EXC_MASK_RPC_ALERT = 1 << @enumToInt(EXC.RPC_ALERT);
+pub const EXC_MASK_CRASH = 1 << @enumToInt(EXC.CRASH);
+pub const EXC_MASK_RESOURCE = 1 << @enumToInt(EXC.RESOURCE);
+pub const EXC_MASK_GUARD = 1 << @enumToInt(EXC.GUARD);
+pub const EXC_MASK_CORPSE_NOTIFY = 1 << @enumToInt(EXC.CORPSE_NOTIFY);
+pub const EXC_MASK_MACHINE = arch_bits.EXC_MASK_MACHINE;
+
+pub const EXC_MASK_ALL = EXC_MASK_BAD_ACCESS |
+    EXC_MASK_BAD_INSTRUCTION |
+    EXC_MASK_ARITHMETIC |
+    EXC_MASK_EMULATION |
+    EXC_MASK_SOFTWARE |
+    EXC_MASK_BREAKPOINT |
+    EXC_MASK_SYSCALL |
+    EXC_MASK_MACH_SYSCALL |
+    EXC_MASK_RPC_ALERT |
+    EXC_MASK_RESOURCE |
+    EXC_MASK_GUARD |
+    EXC_MASK_MACHINE;
+
+/// Send a catch_exception_raise message including the identity.
+pub const EXCEPTION_DEFAULT = 1;
+/// Send a catch_exception_raise_state message including the
+/// thread state.
+pub const EXCEPTION_STATE = 2;
+/// Send a catch_exception_raise_state_identity message including
+/// the thread identity and state.
+pub const EXCEPTION_STATE_IDENTITY = 3;
+/// Send a catch_exception_raise_identity_protected message including protected task
+/// and thread identity.
+pub const EXCEPTION_IDENTITY_PROTECTED = 4;
+/// Prefer sending a catch_exception_raice_backtrace message, if applicable.
+pub const MACH_EXCEPTION_BACKTRACE_PREFERRED = 0x20000000;
+/// include additional exception specific errors, not used yet.
+pub const MACH_EXCEPTION_ERRORS = 0x40000000;
+/// Send 64-bit code and subcode in the exception header */
+pub const MACH_EXCEPTION_CODES = 0x80000000;
+
+pub const MACH_EXCEPTION_MASK = MACH_EXCEPTION_CODES |
+    MACH_EXCEPTION_ERRORS |
+    MACH_EXCEPTION_BACKTRACE_PREFERRED;
+
+pub const TASK_NULL: task_t = 0;
+pub const THREAD_NULL: thread_t = 0;
+pub const MACH_PORT_NULL: mach_port_t = 0;
+pub const MACH_MSG_TIMEOUT_NONE: mach_msg_timeout_t = 0;
+
+pub const MACH_MSG_OPTION_NONE = 0x00000000;
+
+pub const MACH_SEND_MSG = 0x00000001;
+pub const MACH_RCV_MSG = 0x00000002;
+
+pub const MACH_RCV_LARGE = 0x00000004;
+pub const MACH_RCV_LARGE_IDENTITY = 0x00000008;
+
+pub const MACH_SEND_TIMEOUT = 0x00000010;
+pub const MACH_SEND_OVERRIDE = 0x00000020;
+pub const MACH_SEND_INTERRUPT = 0x00000040;
+pub const MACH_SEND_NOTIFY = 0x00000080;
+pub const MACH_SEND_ALWAYS = 0x00010000;
+pub const MACH_SEND_FILTER_NONFATAL = 0x00010000;
+pub const MACH_SEND_TRAILER = 0x00020000;
+pub const MACH_SEND_NOIMPORTANCE = 0x00040000;
+pub const MACH_SEND_NODENAP = MACH_SEND_NOIMPORTANCE;
+pub const MACH_SEND_IMPORTANCE = 0x00080000;
+pub const MACH_SEND_SYNC_OVERRIDE = 0x00100000;
+pub const MACH_SEND_PROPAGATE_QOS = 0x00200000;
+pub const MACH_SEND_SYNC_USE_THRPRI = MACH_SEND_PROPAGATE_QOS;
+pub const MACH_SEND_KERNEL = 0x00400000;
+pub const MACH_SEND_SYNC_BOOTSTRAP_CHECKIN = 0x00800000;
+
+pub const MACH_RCV_TIMEOUT = 0x00000100;
+pub const MACH_RCV_NOTIFY = 0x00000000;
+pub const MACH_RCV_INTERRUPT = 0x00000400;
+pub const MACH_RCV_VOUCHER = 0x00000800;
+pub const MACH_RCV_OVERWRITE = 0x00000000;
+pub const MACH_RCV_GUARDED_DESC = 0x00001000;
+pub const MACH_RCV_SYNC_WAIT = 0x00004000;
+pub const MACH_RCV_SYNC_PEEK = 0x00008000;
+
+pub const MACH_MSG_STRICT_REPLY = 0x00000200;
+
 pub const ucontext_t = extern struct {
     onstack: c_int,
     sigmask: sigset_t,
@@ -155,6 +280,11 @@ pub extern "c" fn @"close$NOCANCEL"(fd: fd_t) c_int;
 pub extern "c" fn mach_host_self() mach_port_t;
 pub extern "c" fn clock_get_time(clock_serv: clock_serv_t, cur_time: *mach_timespec_t) kern_return_t;
 
+pub const exception_type_t = c_int;
+pub const exception_data_type_t = integer_t;
+pub const exception_data_t = ?*mach_exception_data_type_t;
+pub const mach_exception_data_type_t = i64;
+pub const mach_exception_data_t = ?*mach_exception_data_type_t;
 pub const vm_map_t = mach_port_t;
 pub const vm_map_read_t = mach_port_t;
 pub const vm_region_flavor_t = c_int;
@@ -163,19 +293,122 @@ pub const vm_region_recurse_info_t = *c_int;
 pub const mach_vm_address_t = usize;
 pub const vm_offset_t = usize;
 pub const mach_vm_size_t = u64;
+pub const mach_msg_bits_t = c_uint;
+pub const mach_msg_id_t = integer_t;
 pub const mach_msg_type_number_t = natural_t;
+pub const mach_msg_type_name_t = c_uint;
+pub const mach_msg_option_t = integer_t;
+pub const mach_msg_size_t = natural_t;
+pub const mach_msg_timeout_t = natural_t;
+pub const mach_port_right_t = natural_t;
+pub const task_t = mach_port_t;
+pub const thread_port_t = task_t;
+pub const thread_t = thread_port_t;
+pub const exception_mask_t = c_uint;
+pub const exception_mask_array_t = [*]exception_mask_t;
+pub const exception_handler_t = mach_port_t;
+pub const exception_handler_array_t = [*]exception_handler_t;
+pub const exception_port_t = exception_handler_t;
+pub const exception_port_array_t = exception_handler_array_t;
+pub const exception_flavor_array_t = [*]thread_state_flavor_t;
+pub const exception_behavior_t = c_uint;
+pub const exception_behavior_array_t = [*]exception_behavior_t;
+pub const thread_state_flavor_t = c_int;
+pub const ipc_space_t = mach_port_t;
+pub const ipc_space_port_t = ipc_space_t;
+
+pub const MACH_PORT_RIGHT = enum(mach_port_right_t) {
+    SEND = 0,
+    RECEIVE = 1,
+    SEND_ONCE = 2,
+    PORT_SET = 3,
+    DEAD_NAME = 4,
+    /// Obsolete right
+    LABELH = 5,
+    /// Right not implemented
+    NUMBER = 6,
+};
+
+pub const MACH_MSG_TYPE = enum(mach_msg_type_name_t) {
+    /// Must hold receive right
+    MOVE_RECEIVE = 16,
+
+    /// Must hold send right(s)
+    MOVE_SEND = 17,
+
+    /// Must hold sendonce right
+    MOVE_SEND_ONCE = 18,
+
+    /// Must hold send right(s)
+    COPY_SEND = 19,
+
+    /// Must hold receive right
+    MAKE_SEND = 20,
+
+    /// Must hold receive right
+    MAKE_SEND_ONCE = 21,
+
+    /// NOT VALID
+    COPY_RECEIVE = 22,
+
+    /// Must hold receive right
+    DISPOSE_RECEIVE = 24,
+
+    /// Must hold send right(s)
+    DISPOSE_SEND = 25,
+
+    /// Must hold sendonce right
+    DISPOSE_SEND_ONCE = 26,
+};
 
 extern "c" var mach_task_self_: mach_port_t;
 pub fn mach_task_self() callconv(.C) mach_port_t {
     return mach_task_self_;
 }
 
+pub extern "c" fn mach_msg(
+    msg: ?*mach_msg_header_t,
+    option: mach_msg_option_t,
+    send_size: mach_msg_size_t,
+    rcv_size: mach_msg_size_t,
+    rcv_name: mach_port_name_t,
+    timeout: mach_msg_timeout_t,
+    notify: mach_port_name_t,
+) kern_return_t;
+
+pub const mach_msg_header_t = extern struct {
+    msgh_bits: mach_msg_bits_t,
+    msgh_size: mach_msg_size_t,
+    msgh_remote_port: mach_port_t,
+    msgh_local_port: mach_port_t,
+    msgh_voucher_port: mach_port_name_t,
+    msgh_id: mach_msg_id_t,
+};
+
+pub extern "c" fn task_get_exception_ports(
+    task: task_t,
+    exception_mask: exception_mask_t,
+    masks: exception_mask_array_t,
+    masks_cnt: *mach_msg_type_number_t,
+    old_handlers: exception_handler_array_t,
+    old_behaviors: exception_behavior_array_t,
+    old_flavors: exception_flavor_array_t,
+) kern_return_t;
+pub extern "c" fn task_set_exception_ports(
+    task: task_t,
+    exception_mask: exception_mask_t,
+    new_port: mach_port_t,
+    behavior: exception_behavior_t,
+    new_flavor: thread_state_flavor_t,
+) kern_return_t;
+
 pub const task_read_t = mach_port_t;
 
 pub extern "c" fn task_resume(target_task: task_read_t) kern_return_t;
 pub extern "c" fn task_suspend(target_task: task_read_t) kern_return_t;
 
 pub extern "c" fn task_for_pid(target_tport: mach_port_name_t, pid: pid_t, t: *mach_port_name_t) kern_return_t;
+pub extern "c" fn pid_for_task(target_tport: mach_port_name_t, pid: *pid_t) kern_return_t;
 pub extern "c" fn mach_vm_read(
     target_task: vm_map_read_t,
     address: mach_vm_address_t,
@@ -343,7 +576,7 @@ pub const vm_region_submap_short_info_64 = extern struct {
 
 pub const thread_act_t = mach_port_t;
 pub const thread_state_t = *natural_t;
-pub const mach_port_array_t = *mach_port_t;
+pub const mach_port_array_t = [*]mach_port_t;
 
 pub extern "c" fn task_threads(
     target_task: mach_port_t,
@@ -373,6 +606,9 @@ pub extern "c" fn thread_resume(thread: thread_act_t) kern_return_t;
 pub const THREAD_BASIC_INFO = 3;
 pub const THREAD_BASIC_INFO_COUNT: mach_msg_type_number_t = @sizeOf(thread_basic_info) / @sizeOf(natural_t);
 
+pub const THREAD_IDENTIFIER_INFO = 4;
+pub const THREAD_IDENTIFIER_INFO_COUNT: mach_msg_type_number_t = @sizeOf(thread_identifier_info) / @sizeOf(natural_t);
+
 pub const thread_flavor_t = natural_t;
 pub const thread_info_t = *integer_t;
 pub const time_value_t = time_value;
@@ -404,6 +640,17 @@ pub const thread_basic_info = extern struct {
     sleep_time: integer_t,
 };
 
+pub const thread_identifier_info = extern struct {
+    /// System-wide unique 64-bit thread id
+    thread_id: u64,
+
+    /// Handle to be used by libproc
+    thread_handle: u64,
+
+    /// libdispatch queue address
+    dispatch_qaddr: u64,
+};
+
 /// Cachability
 pub const MATTR_CACHE = 1;
 /// Migrability
@@ -506,7 +753,18 @@ pub extern "c" fn mach_vm_protect(
     new_protection: vm_prot_t,
 ) kern_return_t;
 
-pub extern "c" fn mach_port_deallocate(target_tport: mach_port_name_t, task: mach_port_name_t) kern_return_t;
+pub extern "c" fn mach_port_allocate(
+    task: ipc_space_t,
+    right: mach_port_right_t,
+    name: *mach_port_name_t,
+) kern_return_t;
+pub extern "c" fn mach_port_deallocate(task: ipc_space_t, name: mach_port_name_t) kern_return_t;
+pub extern "c" fn mach_port_insert_right(
+    task: ipc_space_t,
+    name: mach_port_name_t,
+    poly: mach_port_t,
+    poly_poly: mach_msg_type_name_t,
+) kern_return_t;
 
 pub extern "c" fn task_info(
     target_task: task_name_t,
@@ -514,6 +772,30 @@ pub extern "c" fn task_info(
     task_info_out: task_info_t,
     task_info_outCnt: *mach_msg_type_number_t,
 ) kern_return_t;
+
+pub const mach_task_basic_info = extern struct {
+    /// Virtual memory size (bytes)
+    virtual_size: mach_vm_size_t,
+
+    /// Resident memory size (bytes)
+    resident_size: mach_vm_size_t,
+
+    /// Total user run time for terminated threads
+    user_time: time_value_t,
+
+    /// Total system run time for terminated threads
+    system_time: time_value_t,
+
+    /// Default policy for new threads
+    policy: policy_t,
+
+    /// Suspend count for task
+    suspend_count: mach_vm_size_t,
+};
+
+pub const MACH_TASK_BASIC_INFO = 20;
+pub const MACH_TASK_BASIC_INFO_COUNT: mach_msg_type_number_t = @sizeOf(mach_task_basic_info) / @sizeOf(natural_t);
+
 pub extern "c" fn _host_page_size(task: mach_port_t, size: *vm_size_t) kern_return_t;
 pub extern "c" fn vm_deallocate(target_task: vm_map_t, address: vm_address_t, size: vm_size_t) kern_return_t;
 pub extern "c" fn vm_machine_attribute(
@@ -1885,11 +2167,11 @@ pub const E = enum(u16) {
 };
 
 pub fn getKernError(err: kern_return_t) KernE {
-    return @intToEnum(KernE, @truncate(u8, @intCast(usize, err)));
+    return @intToEnum(KernE, @truncate(u32, @intCast(usize, err)));
 }
 
 /// Kernel return values
-pub const KernE = enum(u8) {
+pub const KernE = enum(u32) {
     SUCCESS = 0,
 
     /// Specified address is not currently valid
@@ -2108,6 +2390,104 @@ pub const KernE = enum(u8) {
     _,
 };
 
+pub const mach_msg_return_t = kern_return_t;
+
+pub fn getMachMsgError(err: mach_msg_return_t) MachMsgE {
+    return @intToEnum(MachMsgE, @truncate(u32, @intCast(usize, err)));
+}
+
+/// All special error code bits defined below.
+pub const MACH_MSG_MASK: u32 = 0x3e00;
+/// No room in IPC name space for another capability name.
+pub const MACH_MSG_IPC_SPACE: u32 = 0x2000;
+/// No room in VM address space for out-of-line memory.
+pub const MACH_MSG_VM_SPACE: u32 = 0x1000;
+/// Kernel resource shortage handling out-of-line memory.
+pub const MACH_MSG_IPC_KERNEL: u32 = 0x800;
+/// Kernel resource shortage handling an IPC capability.
+pub const MACH_MSG_VM_KERNEL: u32 = 0x400;
+
+/// Mach msg return values
+pub const MachMsgE = enum(u32) {
+    SUCCESS = 0x00000000,
+
+    /// Thread is waiting to send.  (Internal use only.)
+    SEND_IN_PROGRESS = 0x10000001,
+    /// Bogus in-line data.
+    SEND_INVALID_DATA = 0x10000002,
+    /// Bogus destination port.
+    SEND_INVALID_DEST = 0x10000003,
+    ///  Message not sent before timeout expired.
+    SEND_TIMED_OUT = 0x10000004,
+    ///  Bogus voucher port.
+    SEND_INVALID_VOUCHER = 0x10000005,
+    ///  Software interrupt.
+    SEND_INTERRUPTED = 0x10000007,
+    ///  Data doesn't contain a complete message.
+    SEND_MSG_TOO_SMALL = 0x10000008,
+    ///  Bogus reply port.
+    SEND_INVALID_REPLY = 0x10000009,
+    ///  Bogus port rights in the message body.
+    SEND_INVALID_RIGHT = 0x1000000a,
+    ///  Bogus notify port argument.
+    SEND_INVALID_NOTIFY = 0x1000000b,
+    ///  Invalid out-of-line memory pointer.
+    SEND_INVALID_MEMORY = 0x1000000c,
+    ///  No message buffer is available.
+    SEND_NO_BUFFER = 0x1000000d,
+    ///  Send is too large for port
+    SEND_TOO_LARGE = 0x1000000e,
+    ///  Invalid msg-type specification.
+    SEND_INVALID_TYPE = 0x1000000f,
+    ///  A field in the header had a bad value.
+    SEND_INVALID_HEADER = 0x10000010,
+    ///  The trailer to be sent does not match kernel format.
+    SEND_INVALID_TRAILER = 0x10000011,
+    ///  The sending thread context did not match the context on the dest port
+    SEND_INVALID_CONTEXT = 0x10000012,
+    ///  compatibility: no longer a returned error
+    SEND_INVALID_RT_OOL_SIZE = 0x10000015,
+    ///  The destination port doesn't accept ports in body
+    SEND_NO_GRANT_DEST = 0x10000016,
+    ///  Message send was rejected by message filter
+    SEND_MSG_FILTERED = 0x10000017,
+
+    ///  Thread is waiting for receive.  (Internal use only.)
+    RCV_IN_PROGRESS = 0x10004001,
+    ///  Bogus name for receive port/port-set.
+    RCV_INVALID_NAME = 0x10004002,
+    ///  Didn't get a message within the timeout value.
+    RCV_TIMED_OUT = 0x10004003,
+    ///  Message buffer is not large enough for inline data.
+    RCV_TOO_LARGE = 0x10004004,
+    ///  Software interrupt.
+    RCV_INTERRUPTED = 0x10004005,
+    ///  compatibility: no longer a returned error
+    RCV_PORT_CHANGED = 0x10004006,
+    ///  Bogus notify port argument.
+    RCV_INVALID_NOTIFY = 0x10004007,
+    ///  Bogus message buffer for inline data.
+    RCV_INVALID_DATA = 0x10004008,
+    ///  Port/set was sent away/died during receive.
+    RCV_PORT_DIED = 0x10004009,
+    ///  compatibility: no longer a returned error
+    RCV_IN_SET = 0x1000400a,
+    ///  Error receiving message header.  See special bits.
+    RCV_HEADER_ERROR = 0x1000400b,
+    ///  Error receiving message body.  See special bits.
+    RCV_BODY_ERROR = 0x1000400c,
+    ///  Invalid msg-type specification in scatter list.
+    RCV_INVALID_TYPE = 0x1000400d,
+    ///  Out-of-line overwrite region is not large enough
+    RCV_SCATTER_SMALL = 0x1000400e,
+    ///  trailer type or number of trailer elements not supported
+    RCV_INVALID_TRAILER = 0x1000400f,
+    ///  Waiting for receive with timeout. (Internal use only.)
+    RCV_IN_PROGRESS_TIMED = 0x10004011,
+    ///  invalid reply port used in a STRICT_REPLY message
+    RCV_INVALID_REPLY = 0x10004012,
+};
+
 pub const SIGSTKSZ = 131072;
 pub const MINSIGSTKSZ = 32768;
 
@@ -2677,11 +3057,20 @@ pub const _POSIX_SPAWN_RESLIDE = 0x0800;
 pub const POSIX_SPAWN_CLOEXEC_DEFAULT = 0x4000;
 
 pub const PT_TRACE_ME = 0;
+pub const PT_READ_I = 1;
+pub const PT_READ_D = 2;
+pub const PT_READ_U = 3;
+pub const PT_WRITE_I = 4;
+pub const PT_WRITE_D = 5;
+pub const PT_WRITE_U = 6;
 pub const PT_CONTINUE = 7;
 pub const PT_KILL = 8;
 pub const PT_STEP = 9;
 pub const PT_DETACH = 11;
+pub const PT_SIGEXC = 12;
+pub const PT_THUPDATE = 13;
 pub const PT_ATTACHEXC = 14;
+pub const PT_FORCEQUOTA = 30;
 pub const PT_DENY_ATTACH = 31;
 
 pub const caddr_t = ?[*]u8;
diff --git a/lib/std/c/darwin/aarch64.zig b/lib/std/c/darwin/aarch64.zig
index 70153b5dfb..48b03363a1 100644
--- a/lib/std/c/darwin/aarch64.zig
+++ b/lib/std/c/darwin/aarch64.zig
@@ -16,3 +16,23 @@ pub const thread_state = extern struct {
     cpsr: u32, // Current program status register
     __pad: u32,
 };
+
+pub const EXC_TYPES_COUNT = 14;
+pub const EXC_MASK_MACHINE = 0;
+
+pub const ARM_THREAD_STATE = 1;
+pub const ARM_UNIFIED_THREAD_STATE = ARM_THREAD_STATE;
+pub const ARM_VFP_STATE = 2;
+pub const ARM_EXCEPTION_STATE = 3;
+pub const ARM_DEBUG_STATE = 4;
+pub const THREAD_STATE_NONE = 5;
+pub const ARM_THREAD_STATE64 = 6;
+pub const ARM_EXCEPTION_STATE64 = 7;
+pub const ARM_THREAD_STATE_LAST = 8;
+pub const ARM_THREAD_STATE32 = 9;
+pub const ARM_DEBUG_STATE32 = 14;
+pub const ARM_DEBUG_STATE64 = 15;
+pub const ARM_NEON_STATE = 16;
+pub const ARM_NEON_STATE64 = 17;
+pub const ARM_CPMU_STATE64 = 18;
+pub const ARM_PAGEIN_STATE = 27;
diff --git a/lib/std/c/darwin/x86_64.zig b/lib/std/c/darwin/x86_64.zig
index 3d38d34d36..c7671bc23a 100644
--- a/lib/std/c/darwin/x86_64.zig
+++ b/lib/std/c/darwin/x86_64.zig
@@ -33,3 +33,30 @@ pub const thread_state = extern struct {
 
 pub const THREAD_STATE = 4;
 pub const THREAD_STATE_COUNT: c.mach_msg_type_number_t = @sizeOf(thread_state) / @sizeOf(c_int);
+
+pub const EXC_TYPES_COUNT = 14;
+pub const EXC_MASK_MACHINE = 0;
+
+pub const x86_THREAD_STATE32 = 1;
+pub const x86_FLOAT_STATE32 = 2;
+pub const x86_EXCEPTION_STATE32 = 3;
+pub const x86_THREAD_STATE64 = 4;
+pub const x86_FLOAT_STATE64 = 5;
+pub const x86_EXCEPTION_STATE64 = 6;
+pub const x86_THREAD_STATE = 7;
+pub const x86_FLOAT_STATE = 8;
+pub const x86_EXCEPTION_STATE = 9;
+pub const x86_DEBUG_STATE32 = 10;
+pub const x86_DEBUG_STATE64 = 11;
+pub const x86_DEBUG_STATE = 12;
+pub const THREAD_STATE_NONE = 13;
+pub const x86_AVX_STATE32 = 16;
+pub const x86_AVX_STATE64 = (x86_AVX_STATE32 + 1);
+pub const x86_AVX_STATE = (x86_AVX_STATE32 + 2);
+pub const x86_AVX512_STATE32 = 19;
+pub const x86_AVX512_STATE64 = (x86_AVX512_STATE32 + 1);
+pub const x86_AVX512_STATE = (x86_AVX512_STATE32 + 2);
+pub const x86_PAGEIN_STATE = 22;
+pub const x86_THREAD_FULL_STATE64 = 23;
+pub const x86_INSTRUCTION_STATE = 24;
+pub const x86_LAST_BRANCH_STATE = 25;
diff --git a/lib/std/child_process.zig b/lib/std/child_process.zig
index 7d7bea323b..b706f0aecb 100644
--- a/lib/std/child_process.zig
+++ b/lib/std/child_process.zig
@@ -60,6 +60,9 @@ pub const ChildProcess = struct {
     /// Darwin-only. Disable ASLR for the child process.
     disable_aslr: bool = false,
 
+    /// Darwin-only. Start child process in suspended state as if SIGSTOP was sent.
+    start_suspended: bool = false,
+
     pub const Arg0Expand = os.Arg0Expand;
 
     pub const SpawnError = error{
@@ -578,6 +581,9 @@ pub const ChildProcess = struct {
         if (self.disable_aslr) {
             flags |= os.darwin._POSIX_SPAWN_DISABLE_ASLR;
         }
+        if (self.start_suspended) {
+            flags |= os.darwin.POSIX_SPAWN_START_SUSPENDED;
+        }
         try attr.set(flags);
 
         var actions = try os.posix_spawn.Actions.init();
diff --git a/lib/std/os.zig b/lib/std/os.zig
index 4abaccb68d..3d0c7a6351 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -42,6 +42,7 @@ pub const uefi = @import("os/uefi.zig");
 pub const wasi = @import("os/wasi.zig");
 pub const windows = @import("os/windows.zig");
 pub const posix_spawn = @import("os/posix_spawn.zig");
+pub const ptrace = @import("os/ptrace.zig");
 
 comptime {
     assert(@import("std") == std); // std lib tests require --zig-lib-dir
diff --git a/lib/std/os/darwin.zig b/lib/std/os/darwin.zig
index 96d43e4f8e..b3fb681d5a 100644
--- a/lib/std/os/darwin.zig
+++ b/lib/std/os/darwin.zig
@@ -17,11 +17,120 @@ const mach_task = if (builtin.target.isDarwin()) struct {
         Unexpected,
     };
 
-    pub const MachTask = struct {
+    pub const MachTask = extern struct {
         port: std.c.mach_port_name_t,
 
         pub fn isValid(self: MachTask) bool {
-            return self.port != 0;
+            return self.port != std.c.TASK_NULL;
+        }
+
+        pub fn pidForTask(self: MachTask) MachError!std.os.pid_t {
+            var pid: std.os.pid_t = undefined;
+            switch (std.c.getKernError(std.c.pid_for_task(self.port, &pid))) {
+                .SUCCESS => return pid,
+                .FAILURE => return error.PermissionDenied,
+                else => |err| {
+                    log.err("pid_for_task kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub fn allocatePort(self: MachTask, right: std.c.MACH_PORT_RIGHT) MachError!MachTask {
+            var out_port: std.c.mach_port_name_t = undefined;
+            switch (std.c.getKernError(std.c.mach_port_allocate(
+                self.port,
+                @enumToInt(right),
+                &out_port,
+            ))) {
+                .SUCCESS => return .{ .port = out_port },
+                .FAILURE => return error.PermissionDenied,
+                else => |err| {
+                    log.err("mach_task_allocate kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub fn deallocatePort(self: MachTask, port: MachTask) void {
+            _ = std.c.getKernError(std.c.mach_port_deallocate(self.port, port.port));
+        }
+
+        pub fn insertRight(self: MachTask, port: MachTask, msg: std.c.MACH_MSG_TYPE) !void {
+            switch (std.c.getKernError(std.c.mach_port_insert_right(
+                self.port,
+                port.port,
+                port.port,
+                @enumToInt(msg),
+            ))) {
+                .SUCCESS => return,
+                .FAILURE => return error.PermissionDenied,
+                else => |err| {
+                    log.err("mach_port_insert_right kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub const PortInfo = struct {
+            mask: std.c.exception_mask_t,
+            masks: [std.c.EXC_TYPES_COUNT]std.c.exception_mask_t,
+            ports: [std.c.EXC_TYPES_COUNT]std.c.mach_port_t,
+            behaviors: [std.c.EXC_TYPES_COUNT]std.c.exception_behavior_t,
+            flavors: [std.c.EXC_TYPES_COUNT]std.c.thread_state_flavor_t,
+            count: std.c.mach_msg_type_number_t,
+        };
+
+        pub fn getExceptionPorts(self: MachTask, mask: std.c.exception_mask_t) !PortInfo {
+            var info = PortInfo{
+                .mask = mask,
+                .masks = undefined,
+                .ports = undefined,
+                .behaviors = undefined,
+                .flavors = undefined,
+                .count = 0,
+            };
+            info.count = info.ports.len / @sizeOf(std.c.mach_port_t);
+
+            switch (std.c.getKernError(std.c.task_get_exception_ports(
+                self.port,
+                info.mask,
+                &info.masks,
+                &info.count,
+                &info.ports,
+                &info.behaviors,
+                &info.flavors,
+            ))) {
+                .SUCCESS => return info,
+                .FAILURE => return error.PermissionDenied,
+                else => |err| {
+                    log.err("task_get_exception_ports kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub fn setExceptionPorts(
+            self: MachTask,
+            mask: std.c.exception_mask_t,
+            new_port: MachTask,
+            behavior: std.c.exception_behavior_t,
+            new_flavor: std.c.thread_state_flavor_t,
+        ) !void {
+            switch (std.c.getKernError(std.c.task_set_exception_ports(
+                self.port,
+                mask,
+                new_port.port,
+                behavior,
+                new_flavor,
+            ))) {
+                .SUCCESS => return,
+                .FAILURE => return error.PermissionDenied,
+                else => |err| {
+                    log.err("task_set_exception_ports kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
         }
 
         pub const RegionInfo = struct {
@@ -304,6 +413,110 @@ const mach_task = if (builtin.target.isDarwin()) struct {
                 },
             }
         }
+
+        pub fn basicTaskInfo(task: MachTask) MachError!std.c.mach_task_basic_info {
+            var info: std.c.mach_task_basic_info = undefined;
+            var count = std.c.MACH_TASK_BASIC_INFO_COUNT;
+            switch (std.c.getKernError(std.c.task_info(
+                task.port,
+                std.c.MACH_TASK_BASIC_INFO,
+                @ptrCast(std.c.task_info_t, &info),
+                &count,
+            ))) {
+                .SUCCESS => return info,
+                else => |err| {
+                    log.err("task_info kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub fn @"resume"(task: MachTask) MachError!void {
+            switch (std.c.getKernError(std.c.task_resume(task.port))) {
+                .SUCCESS => {},
+                else => |err| {
+                    log.err("task_resume kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub fn @"suspend"(task: MachTask) MachError!void {
+            switch (std.c.getKernError(std.c.task_suspend(task.port))) {
+                .SUCCESS => {},
+                else => |err| {
+                    log.err("task_suspend kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        const ThreadList = struct {
+            buf: []MachThread,
+
+            pub fn deinit(list: ThreadList) void {
+                const self_task = machTaskForSelf();
+                _ = std.c.vm_deallocate(
+                    self_task.port,
+                    @ptrToInt(list.buf.ptr),
+                    @intCast(std.c.vm_size_t, list.buf.len * @sizeOf(std.c.mach_port_t)),
+                );
+            }
+        };
+
+        pub fn getThreads(task: MachTask) MachError!ThreadList {
+            var thread_list: std.c.mach_port_array_t = undefined;
+            var thread_count: std.c.mach_msg_type_number_t = undefined;
+            switch (std.c.getKernError(std.c.task_threads(task.port, &thread_list, &thread_count))) {
+                .SUCCESS => return ThreadList{ .buf = @ptrCast([*]MachThread, thread_list)[0..thread_count] },
+                else => |err| {
+                    log.err("task_threads kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+    };
+
+    pub const MachThread = extern struct {
+        port: std.c.mach_port_t,
+
+        pub fn isValid(thread: MachThread) bool {
+            return thread.port != std.c.THREAD_NULL;
+        }
+
+        pub fn getBasicInfo(thread: MachThread) MachError!std.c.thread_basic_info {
+            var info: std.c.thread_basic_info = undefined;
+            var count = std.c.THREAD_BASIC_INFO_COUNT;
+            switch (std.c.getKernError(std.c.thread_info(
+                thread.port,
+                std.c.THREAD_BASIC_INFO,
+                @ptrCast(std.c.thread_info_t, &info),
+                &count,
+            ))) {
+                .SUCCESS => return info,
+                else => |err| {
+                    log.err("thread_info kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
+
+        pub fn getIdentifierInfo(thread: MachThread) MachError!std.c.thread_identifier_info {
+            var info: std.c.thread_identifier_info = undefined;
+            var count = std.c.THREAD_IDENTIFIER_INFO_COUNT;
+            switch (std.c.getKernError(std.c.thread_info(
+                thread.port,
+                std.c.THREAD_IDENTIFIER_INFO,
+                @ptrCast(std.c.thread_info_t, &info),
+                &count,
+            ))) {
+                .SUCCESS => return info,
+                else => |err| {
+                    log.err("thread_info kernel call failed with error code: {s}", .{@tagName(err)});
+                    return error.Unexpected;
+                },
+            }
+        }
     };
 
     pub fn machTaskForPid(pid: std.os.pid_t) MachError!MachTask {
diff --git a/lib/std/os/ptrace.zig b/lib/std/os/ptrace.zig
new file mode 100644
index 0000000000..afe0b51e2e
--- /dev/null
+++ b/lib/std/os/ptrace.zig
@@ -0,0 +1,28 @@
+const std = @import("std");
+const builtin = @import("builtin");
+
+const os = @import("../os.zig");
+const system = os.system;
+const errno = system.getErrno;
+const pid_t = system.pid_t;
+const unexpectedErrno = os.unexpectedErrno;
+const UnexpectedError = os.UnexpectedError;
+
+pub usingnamespace ptrace;
+
+const ptrace = if (builtin.target.isDarwin()) struct {
+    pub const PtraceError = error{
+        ProcessNotFound,
+        PermissionDenied,
+    } || UnexpectedError;
+
+    pub fn ptrace(request: i32, pid: pid_t, addr: ?[*]u8, signal: i32) PtraceError!void {
+        switch (errno(system.ptrace(request, pid, addr, signal))) {
+            .SUCCESS => return,
+            .SRCH => return error.ProcessNotFound,
+            .INVAL => unreachable,
+            .BUSY, .PERM => return error.PermissionDenied,
+            else => |err| return unexpectedErrno(err),
+        }
+    }
+} else struct {};