From 0dac8402cf77442c7f16fe7a17c7a313e8ca41d9 Mon Sep 17 00:00:00 2001
From: torque <torque@epicyclic.dev>
Date: Thu, 24 Aug 2023 20:11:27 -0700
Subject: [PATCH] thunks: also aligncast userdata

This is probably the sort of thing that I wouldn't actually think of
having explicit test coverage for if I hadn't accidentally ran across
it while fiddling. I will compensate for this easily by not actually
writing tests at all.
---
 src/connection.zig   | 14 +++++++-------
 src/subscription.zig |  2 +-
 src/thunk.zig        |  2 +-
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/connection.zig b/src/connection.zig
index a4cd644..b6db633 100644
--- a/src/connection.zig
+++ b/src/connection.zig
@@ -893,7 +893,7 @@ pub fn makeConnectionCallbackThunk(
     return struct {
         fn thunk(conn: ?*nats_c.natsConnection, userdata: ?*anyopaque) callconv(.C) void {
             const connection: *Connection = if (conn) |c| @ptrCast(c) else unreachable;
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
             callback(connection, data);
         }
     }.thunk;
@@ -916,7 +916,7 @@ pub fn makeReconnectDelayCallbackThunk(
             userdata: ?*anyopaque,
         ) callconv(.C) i64 {
             const connection: *Connection = if (conn) |c| @ptrCast(c) else unreachable;
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
             return callback(connection, attempts, data);
         }
     }.thunk;
@@ -946,7 +946,7 @@ pub fn makeErrorHandlerCallbackThunk(
         ) callconv(.C) void {
             const connection: *Connection = if (conn) |c| @ptrCast(c) else unreachable;
             const subscription: *Subscription = if (sub) |s| @ptrCast(s) else unreachable;
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
 
             callback(connection, subscription, Status.fromInt(status), data);
         }
@@ -1005,7 +1005,7 @@ pub fn makeEventLoopAddRemoveCallbackThunk(
             userdata: ?*anyopaque,
         ) callconv(.C) nats_c.natsStatus {
             const connection: *Connection = if (conn) |c| @ptrCast(c) else unreachable;
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
             callback(connection, attempts, data) catch |err|
                 return Status.fromError(err).toInt();
 
@@ -1028,7 +1028,7 @@ pub fn makeEventLoopDetachCallbackThunk(
         fn thunk(
             userdata: ?*anyopaque,
         ) callconv(.C) nats_c.natsStatus {
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
             callback(data) catch |err| return Status.fromError(err).toInt();
             return nats_c.NATS_OK;
         }
@@ -1058,7 +1058,7 @@ pub fn makeJwtHandlerCallbackThunk(
             err_out: *?[*:0]u8,
             userdata: ?*anyopaque,
         ) callconv(.C) nats_c.natsStatus {
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
 
             switch (callback(data)) {
                 .jwt => |jwt| {
@@ -1099,7 +1099,7 @@ pub fn makeSignatureHandlerCallbackThunk(
             nonce: [*:0]const u8,
             userdata: ?*anyopaque,
         ) callconv(.C) nats_c.natsStatus {
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
 
             switch (callback(std.mem.sliceTo(nonce, 0), data)) {
                 .signature => |sig| {
diff --git a/src/subscription.zig b/src/subscription.zig
index 92c8aae..2d9b415 100644
--- a/src/subscription.zig
+++ b/src/subscription.zig
@@ -197,7 +197,7 @@ pub fn makeSubscriptionCallbackThunk(
             const connection: *Connection = if (conn) |c| @ptrCast(c) else unreachable;
             const subscription: *Subscription = if (sub) |s| @ptrCast(s) else unreachable;
 
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
 
             callback(data, connection, subscription, message);
         }
diff --git a/src/thunk.zig b/src/thunk.zig
index 5d26a26..2ceb0ad 100644
--- a/src/thunk.zig
+++ b/src/thunk.zig
@@ -16,7 +16,7 @@ pub fn makeSimpleCallbackThunk(
 ) *const SimpleCallback {
     return struct {
         fn thunk(userdata: ?*anyopaque) callconv(.C) void {
-            const data: *T = if (userdata) |u| @ptrCast(u) else unreachable;
+            const data: *T = if (userdata) |u| @alignCast(@ptrCast(u)) else unreachable;
             callback(data);
         }
     }.thunk;