From 576ffaa3298b4e99b7e46d4eccad4763b18985f8 Mon Sep 17 00:00:00 2001
From: kcbanner <kcbanner@gmail.com>
Date: Tue, 4 Jul 2023 13:40:50 -0400
Subject: [PATCH] darwin: update mcontext_t definition for aarch64 to add neon
 state

---
 lib/std/c/darwin.zig         |  6 +-----
 lib/std/c/darwin/aarch64.zig | 13 +++++++++++++
 lib/std/c/darwin/x86_64.zig  |  6 ++++++
 lib/std/debug.zig            |  9 ++++++++-
 4 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/lib/std/c/darwin.zig b/lib/std/c/darwin.zig
index 5f281912215bba2cc096087d8b7328ae128aae3a..1901271b83c2463c414c2eb1b20fd2568abcbaa7 100644
--- a/lib/std/c/darwin.zig
+++ b/lib/std/c/darwin.zig
@@ -151,11 +151,7 @@ pub const ucontext_t = extern struct {
     __mcontext_data: mcontext_t,
 };
 
-pub const mcontext_t = extern struct {
-    es: arch_bits.exception_state,
-    ss: arch_bits.thread_state,
-    fs: arch_bits.float_state,
-};
+pub const mcontext_t = arch_bits.mcontext_t;
 
 extern "c" fn __error() *c_int;
 pub extern "c" fn NSVersionOfRunTimeLibrary(library_name: [*:0]const u8) u32;
diff --git a/lib/std/c/darwin/aarch64.zig b/lib/std/c/darwin/aarch64.zig
index 48b03363a165a790c0c5beb0884d30386eb83a88..d00b92af83838978867fa103f3106e9abf13dd58 100644
--- a/lib/std/c/darwin/aarch64.zig
+++ b/lib/std/c/darwin/aarch64.zig
@@ -1,5 +1,12 @@
 // See C headers in
 // lib/libc/include/aarch64-macos.12-gnu/mach/arm/_structs.h
+// lib/libc/include/aarch64-macos.13-none/arm/_mcontext.h
+
+pub const mcontext_t = extern struct {
+    es: exception_state,
+    ss: thread_state,
+    ns: neon_state,
+};
 
 pub const exception_state = extern struct {
     far: u64, // Virtual Fault Address
@@ -17,6 +24,12 @@ pub const thread_state = extern struct {
     __pad: u32,
 };
 
+pub const neon_state = extern struct {
+    q: [32]u128,
+    fpsr: u32,
+    fpcr: u32,
+};
+
 pub const EXC_TYPES_COUNT = 14;
 pub const EXC_MASK_MACHINE = 0;
 
diff --git a/lib/std/c/darwin/x86_64.zig b/lib/std/c/darwin/x86_64.zig
index db94840d9da2f5a5284792e706a06114d7bd704b..7b66fb2e97987da8f29d7825601ed9ac6fada23f 100644
--- a/lib/std/c/darwin/x86_64.zig
+++ b/lib/std/c/darwin/x86_64.zig
@@ -1,5 +1,11 @@
 const c = @import("../darwin.zig");
 
+pub const mcontext_t = extern struct {
+    es: exception_state,
+    ss: thread_state,
+    fs: float_state,
+};
+
 pub const exception_state = extern struct {
     trapno: u16,
     cpu: u16,
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index 249674e0d40d71e7852e97e55f73f6b102f758eb..eef65bd6770eb35f5cd4b415c905602719b50ad0 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -445,7 +445,14 @@ pub inline fn getContext(context: *StackTraceContext) bool {
     }
 
     const result = have_getcontext and os.system.getcontext(context) == 0;
-    if (native_os == .macos) assert(context.mcsize == @sizeOf(std.c.mcontext_t));
+    if (native_os == .macos) {
+        // TODO: Temp, to discover this size via aarch64 CI
+        if (context.mcsize != @sizeOf(std.c.mcontext_t)) {
+            print("context.mcsize does not match! {} vs {}\n", .{ context.mcsize, @sizeOf(std.c.mcontext_t)});
+        }
+
+        assert(context.mcsize == @sizeOf(std.c.mcontext_t));
+    }
 
     return result;
 }
-- 
2.54.0