From 200754223188db30c4134012c1cbc6ee39916925 Mon Sep 17 00:00:00 2001
From: Stephen Gutekanst <stephen@hexops.com>
Date: Tue, 16 Aug 2022 21:29:06 -0700
Subject: [PATCH] gpu: correctly allow unsetting
 Device.setUncapturedErrorCallback

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
---
 gpu/src/dawn_impl.zig |  2 +-
 gpu/src/device.zig    | 21 ++++++++++++---------
 gpu/src/interface.zig |  7 ++++---
 gpu/src/queue.zig     |  2 +-
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/gpu/src/dawn_impl.zig b/gpu/src/dawn_impl.zig
index 8a9d603b..75653bc5 100644
--- a/gpu/src/dawn_impl.zig
+++ b/gpu/src/dawn_impl.zig
@@ -619,7 +619,7 @@ pub const Interface = struct {
         );
     }
 
-    pub inline fn deviceSetUncapturedErrorCallback(device: *gpu.Device, callback: gpu.ErrorCallback, userdata: ?*anyopaque) void {
+    pub inline fn deviceSetUncapturedErrorCallback(device: *gpu.Device, callback: ?gpu.ErrorCallback, userdata: ?*anyopaque) void {
         procs.deviceSetUncapturedErrorCallback.?(
             @ptrCast(c.WGPUDevice, device),
             @ptrCast(c.WGPUErrorCallback, callback),
diff --git a/gpu/src/device.zig b/gpu/src/device.zig
index 13513736..b2a1a243 100644
--- a/gpu/src/device.zig
+++ b/gpu/src/device.zig
@@ -297,19 +297,22 @@ pub const Device = opaque {
         Impl.deviceSetLoggingCallback(device, Helper.callback, if (Context == void) null else context);
     }
 
-    // TODO: presumably callback should be nullable for unsetting
     pub inline fn setUncapturedErrorCallback(
         device: *Device,
         context: anytype,
-        comptime callback: fn (ctx: @TypeOf(context), typ: ErrorType, message: [*:0]const u8) callconv(.Inline) void,
+        comptime callback: ?fn (ctx: @TypeOf(context), typ: ErrorType, message: [*:0]const u8) callconv(.Inline) void,
     ) void {
-        const Context = @TypeOf(context);
-        const Helper = struct {
-            pub fn callback(typ: ErrorType, message: [*:0]const u8, userdata: ?*anyopaque) callconv(.C) void {
-                callback(if (Context == void) {} else @ptrCast(Context, @alignCast(@alignOf(std.meta.Child(Context)), userdata)), typ, message);
-            }
-        };
-        Impl.deviceSetUncapturedErrorCallback(device, Helper.callback, if (Context == void) null else context);
+        if (callback) |cb| {
+            const Context = @TypeOf(context);
+            const Helper = struct {
+                pub fn callback(typ: ErrorType, message: [*:0]const u8, userdata: ?*anyopaque) callconv(.C) void {
+                    cb(if (Context == void) {} else @ptrCast(Context, @alignCast(@alignOf(std.meta.Child(Context)), userdata)), typ, message);
+                }
+            };
+            Impl.deviceSetUncapturedErrorCallback(device, Helper.callback, if (Context == void) null else context);
+        } else {
+            Impl.deviceSetUncapturedErrorCallback(device, null, null);
+        }
     }
 
     pub inline fn tick(device: *Device) void {
diff --git a/gpu/src/interface.zig b/gpu/src/interface.zig
index adac06d9..d278db2a 100644
--- a/gpu/src/interface.zig
+++ b/gpu/src/interface.zig
@@ -112,7 +112,7 @@ pub fn Interface(comptime T: type) type {
     assertDecl(T, "deviceSetDeviceLostCallback", fn (device: *gpu.Device, callback: ?gpu.Device.LostCallback, userdata: ?*anyopaque) callconv(.Inline) void);
     assertDecl(T, "deviceSetLabel", fn (device: *gpu.Device, label: [*:0]const u8) callconv(.Inline) void);
     assertDecl(T, "deviceSetLoggingCallback", fn (device: *gpu.Device, callback: gpu.LoggingCallback, userdata: ?*anyopaque) callconv(.Inline) void);
-    assertDecl(T, "deviceSetUncapturedErrorCallback", fn (device: *gpu.Device, callback: gpu.ErrorCallback, userdata: ?*anyopaque) callconv(.Inline) void);
+    assertDecl(T, "deviceSetUncapturedErrorCallback", fn (device: *gpu.Device, callback: ?gpu.ErrorCallback, userdata: ?*anyopaque) callconv(.Inline) void);
     assertDecl(T, "deviceTick", fn (device: *gpu.Device) callconv(.Inline) void);
     assertDecl(T, "deviceReference", fn (device: *gpu.Device) callconv(.Inline) void);
     assertDecl(T, "deviceRelease", fn (device: *gpu.Device) callconv(.Inline) void);
@@ -704,8 +704,9 @@ pub fn Export(comptime T: type) type {
             T.deviceSetLoggingCallback(device, callback, userdata);
         }
 
+        // TODO: dawn: callback not marked as nullable in dawn.json but in fact is.
         // WGPU_EXPORT void wgpuDeviceSetUncapturedErrorCallback(WGPUDevice device, WGPUErrorCallback callback, void * userdata);
-        export fn wgpuDeviceSetUncapturedErrorCallback(device: *gpu.Device, callback: gpu.ErrorCallback, userdata: ?*anyopaque) void {
+        export fn wgpuDeviceSetUncapturedErrorCallback(device: *gpu.Device, callback: ?gpu.ErrorCallback, userdata: ?*anyopaque) void {
             T.deviceSetUncapturedErrorCallback(device, callback, userdata);
         }
 
@@ -1812,7 +1813,7 @@ pub const StubInterface = Interface(struct {
         unreachable;
     }
 
-    pub inline fn deviceSetUncapturedErrorCallback(device: *gpu.Device, callback: gpu.ErrorCallback, userdata: ?*anyopaque) void {
+    pub inline fn deviceSetUncapturedErrorCallback(device: *gpu.Device, callback: ?gpu.ErrorCallback, userdata: ?*anyopaque) void {
         _ = device;
         _ = callback;
         _ = userdata;
diff --git a/gpu/src/queue.zig b/gpu/src/queue.zig
index 7017fbe8..3aee0502 100644
--- a/gpu/src/queue.zig
+++ b/gpu/src/queue.zig
@@ -30,7 +30,7 @@ pub const Queue = opaque {
         Impl.queueCopyTextureForBrowser(queue, source, destination, copy_size, options);
     }
 
-    // TODO: presumably callback should be nullable for unsetting
+    // TODO: dawn: does not allow unsetting this callback to null
     pub inline fn onSubmittedWorkDone(
         queue: *Queue,
         signal_value: u64,