From 0aab3bda126b0221f81533b335c7a6a01749344b Mon Sep 17 00:00:00 2001
From: Jakub Konka <kubkon@jakubkonka.com>
Date: Fri, 17 Mar 2023 14:51:08 +0100
Subject: [PATCH] macho: add wrappers for attaching/detaching from HCS process

---
 src/link.zig       | 23 +++++------------------
 src/link/MachO.zig | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/src/link.zig b/src/link.zig
index c87d5b5dd575fe539cefcb3cf09cdb6de947aa10..ae6c02c08bad7f91dea552fde235648b29302603 100644
--- a/src/link.zig
+++ b/src/link.zig
@@ -392,19 +392,8 @@ pub const File = struct {
                         .linux => std.os.ptrace(std.os.linux.PTRACE.ATTACH, pid, 0, 0) catch |err| {
                             log.warn("ptrace failure: {s}", .{@errorName(err)});
                         },
-                        .macos => {
-                            const macho = base.cast(MachO).?;
-                            if (macho.mach_task == null) {
-                                if (std.os.darwin.machTaskForPid(pid)) |task| {
-                                    macho.mach_task = task;
-                                    // TODO enable ones we register for exceptions
-                                    // std.os.ptrace(std.os.darwin.PT.ATTACHEXC, pid, 0, 0) catch |err| {
-                                    //     log.warn("ptrace failure: {s}", .{@errorName(err)});
-                                    // };
-                                } else |err| {
-                                    log.warn("failed to acquire Mach task for child process: {s}", .{@errorName(err)});
-                                }
-                            }
+                        .macos => base.cast(MachO).?.ptraceAttach(pid) catch |err| {
+                            log.warn("attaching failed with error: {s}", .{@errorName(err)});
                         },
                         else => return error.HotSwapUnavailableOnHostOperatingSystem,
                     }
@@ -444,11 +433,9 @@ pub const File = struct {
                         .linux => std.os.ptrace(std.os.linux.PTRACE.DETACH, pid, 0, 0) catch |err| {
                             log.warn("ptrace failure: {s}", .{@errorName(err)});
                         },
-                        .macos => {},
-                        // TODO see comment above in makeWritable
-                        // .macos => std.os.ptrace(std.os.darwin.PT.DETACH, pid, 0, 0) catch |err| {
-                        //     log.warn("ptrace failure: {s}", .{@errorName(err)});
-                        // },
+                        .macos => base.cast(MachO).?.ptraceDetach(pid) catch |err| {
+                            log.warn("detaching failed with error: {s}", .{@errorName(err)});
+                        },
                         else => return error.HotSwapUnavailableOnHostOperatingSystem,
                     }
                 }
diff --git a/src/link/MachO.zig b/src/link/MachO.zig
index 869061be38cf89407acdc02a9be19c20930fa952..3d0b8b2f778574de7df7ac69bcd544fbc60a88a1 100644
--- a/src/link/MachO.zig
+++ b/src/link/MachO.zig
@@ -3811,6 +3811,28 @@ pub fn allocatedVirtualSize(self: *MachO, start: u64) u64 {
     return min_pos - start;
 }
 
+pub fn ptraceAttach(self: *MachO, pid: std.os.pid_t) !void {
+    const mach_task = try std.os.darwin.machTaskForPid(pid);
+    log.debug("Mach task for pid {d}: {any}", .{ pid, mach_task });
+    self.mach_task = mach_task;
+
+    // TODO start exception handler in another thread
+
+    // TODO enable ones we register for exceptions
+    // try std.os.ptrace(std.os.darwin.PT.ATTACHEXC, pid, 0, 0);
+}
+
+pub fn ptraceDetach(self: *MachO, pid: std.os.pid_t) !void {
+    _ = pid;
+
+    // TODO stop exception handler
+
+    // TODO see comment in ptraceAttach
+    // try std.os.ptrace(std.os.darwin.PT.DETACH, pid, 0, 0);
+
+    self.mach_task = null;
+}
+
 pub fn makeStaticString(bytes: []const u8) [16]u8 {
     var buf = [_]u8{0} ** 16;
     assert(bytes.len <= buf.len);
-- 
2.54.0