Add and document many synchronous error statuses

Fixes #255
Fixes (again?) #291
Issue #225
Fixes #64

doc/articles/Errors.md

@@ -0,0 +1,42 @@
+# Errors {#Errors}
+
+Errors are surfaced in several ways.
+
+Most errors only result from incorrect use of the API and should not need to be handled at runtime.
+However, a few (@ref WGPUErrorType_OutOfMemory, @ref WGPUErrorType_Internal) are potentially useful to handle.
+
+## Device Error {#DeviceError}
+
+These behave the same way as [in the WebGPU JavaScript API specification](https://www.w3.org/TR/webgpu/#errors-and-debugging).
+They are receivable via @ref wgpuDevicePopErrorScope() and @ref WGPUDeviceDescriptor::uncapturedErrorCallbackInfo.
+
+These errors include:
+
+- All device-timeline errors in the WebGPU specification.
+- Enum values which are numerically invalid (this is not possible in JavaScript).
+- Enum values which are require features not enabled on the device (a [content-timeline](https://www.w3.org/TR/webgpu/#content-timeline) error in JavaScript), for example compressed texture formats.
+- Other content-timeline errors where specified.
+
+## Callback Errors {#CallbackErrors}
+
+These behave similarly to the Promise-returning JavaScript APIs. Instead of there being two callbacks like in JavaScript (one for resolve and one for reject), there is a single callback which receives a status code, and depending on the status, _either_ a valid result with an empty message string (`{NULL, 0}`), _or_ an invalid result with a non-empty message string.
+
+## Synchronous Errors {#SynchronousErrors}
+
+These errors include:
+
+- @ref StructChainingError cases.
+- [Content-timeline](https://www.w3.org/TR/webgpu/#content-timeline) errors other than those which are surfaced as @ref DeviceError in `webgpu.h`. See specific documentation to determine how each error is exposed.
+
+Generally these will return some kind of failure status (like \ref WGPUStatus_Error), or `NULL`.
+
+### Struct-Chaining Error {#StructChainingError}
+
+A struct-chaining error happens when the `SType` of a struct in a struct chain is not valid for that chain.
+The API returns a failure status or `NULL` and produces an @ref ImplementationDefinedLogging message.
+
+### Implementation-Defined Logging {#ImplementationDefinedLogging}
+
+Entry points may also specify that they produce "implementation-defined logging".
+These messages are logged in an implementation defined way (e.g. to an implementation-specific callback, or to a logging runtime).
+They are intended to be intended to be read by humans, useful primarily for development and crash reporting.

doc/articles/index.md

@@ -1,6 +1,7 @@
 \page articles Articles
 
 - \subpage Asynchronous-Operations
+- \subpage Errors
 - \subpage Ownership
 - \subpage Surfaces
 - \subpage SentinelValues

webgpu.h

@@ -737,8 +737,8 @@ typedef enum WGPUSamplerBindingType {
 
 /**
  * Status code returned (synchronously) from many operations. Generally
- * indicates an invalid input like an unknown enum value or struct chaining
- * error. Read the function's documentation for specific error conditions.
+ * indicates an invalid input like an unknown enum value or @ref StructChainingError.
+ * Read the function's documentation for specific error conditions.
  */
 typedef enum WGPUStatus {
  WGPUStatus_Success = 0x00000001,
@@ -832,6 +832,11 @@ typedef enum WGPUSurfaceGetCurrentTextureStatus {
  * The @ref WGPUDevice configured on the @ref WGPUSurface was lost.
  */
  WGPUSurfaceGetCurrentTextureStatus_DeviceLost = 0x00000007,
+ /**
+ * `0x00000008`.
+ * The surface is not configured, or there was a @ref StructChainingError.
+ */
+ WGPUSurfaceGetCurrentTextureStatus_Error = 0x00000008,
  WGPUSurfaceGetCurrentTextureStatus_Force32 = 0x7FFFFFFF
 } WGPUSurfaceGetCurrentTextureStatus WGPU_ENUM_ATTRIBUTE;
 
@@ -2137,7 +2142,7 @@ typedef WGPUInstance (*WGPUProcCreateInstance)(WGPU_NULLABLE WGPUInstanceDescrip
  * Proc pointer type for @ref wgpuGetInstanceFeatures:
  * > @copydoc wgpuGetInstanceFeatures
  */
-typedef void (*WGPUProcGetInstanceFeatures)(WGPUInstanceFeatures * features) WGPU_FUNCTION_ATTRIBUTE;
+typedef WGPUStatus (*WGPUProcGetInstanceFeatures)(WGPUInstanceFeatures * features) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Proc pointer type for @ref wgpuGetProcAddress:
  * > @copydoc wgpuGetProcAddress
@@ -2154,12 +2159,12 @@ typedef WGPUStatus (*WGPUProcAdapterGetFeatures)(WGPUAdapter adapter, WGPUSuppor
  * Proc pointer type for @ref wgpuAdapterGetInfo:
  * > @copydoc wgpuAdapterGetInfo
  */
-typedef void (*WGPUProcAdapterGetInfo)(WGPUAdapter adapter, WGPUAdapterInfo * info) WGPU_FUNCTION_ATTRIBUTE;
+typedef WGPUStatus (*WGPUProcAdapterGetInfo)(WGPUAdapter adapter, WGPUAdapterInfo * info) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Proc pointer type for @ref wgpuAdapterGetLimits:
  * > @copydoc wgpuAdapterGetLimits
  */
-typedef WGPUBool (*WGPUProcAdapterGetLimits)(WGPUAdapter adapter, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
+typedef WGPUStatus (*WGPUProcAdapterGetLimits)(WGPUAdapter adapter, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Proc pointer type for @ref wgpuAdapterHasFeature:
  * > @copydoc wgpuAdapterHasFeature
@@ -2542,7 +2547,7 @@ typedef WGPUStatus (*WGPUProcDeviceGetFeatures)(WGPUDevice device, WGPUSupported
  * Proc pointer type for @ref wgpuDeviceGetLimits:
  * > @copydoc wgpuDeviceGetLimits
  */
-typedef WGPUBool (*WGPUProcDeviceGetLimits)(WGPUDevice device, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
+typedef WGPUStatus (*WGPUProcDeviceGetLimits)(WGPUDevice device, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Proc pointer type for @ref wgpuDeviceGetQueue:
  * > @copydoc wgpuDeviceGetQueue
@@ -2981,12 +2986,12 @@ typedef void (*WGPUProcSupportedFeaturesFreeMembers)(WGPUSupportedFeatures suppo
  * Proc pointer type for @ref wgpuSurfaceConfigure:
  * > @copydoc wgpuSurfaceConfigure
  */
-typedef void (*WGPUProcSurfaceConfigure)(WGPUSurface surface, WGPUSurfaceConfiguration const * config) WGPU_FUNCTION_ATTRIBUTE;
+typedef WGPUStatus (*WGPUProcSurfaceConfigure)(WGPUSurface surface, WGPUSurfaceConfiguration const * config) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Proc pointer type for @ref wgpuSurfaceGetCapabilities:
  * > @copydoc wgpuSurfaceGetCapabilities
  */
-typedef WGPUBool (*WGPUProcSurfaceGetCapabilities)(WGPUSurface surface, WGPUAdapter adapter, WGPUSurfaceCapabilities * capabilities) WGPU_FUNCTION_ATTRIBUTE;
+typedef WGPUStatus (*WGPUProcSurfaceGetCapabilities)(WGPUSurface surface, WGPUAdapter adapter, WGPUSurfaceCapabilities * capabilities) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Proc pointer type for @ref wgpuSurfaceGetCurrentTexture:
  * > @copydoc wgpuSurfaceGetCurrentTexture
@@ -2996,7 +3001,7 @@ typedef void (*WGPUProcSurfaceGetCurrentTexture)(WGPUSurface surface, WGPUSurfac
  * Proc pointer type for @ref wgpuSurfacePresent:
  * > @copydoc wgpuSurfacePresent
  */
-typedef void (*WGPUProcSurfacePresent)(WGPUSurface surface) WGPU_FUNCTION_ATTRIBUTE;
+typedef WGPUStatus (*WGPUProcSurfacePresent)(WGPUSurface surface) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Proc pointer type for @ref wgpuSurfaceSetLabel:
  * > @copydoc wgpuSurfaceSetLabel
@@ -3127,8 +3132,11 @@ WGPU_EXPORT WGPUInstance wgpuCreateInstance(WGPU_NULLABLE WGPUInstanceDescriptor
  *
  * @param features
  * The supported instance features
+ *
+ * @returns
+ * Returns @ref WGPUStatus_Error (and leaves `features` unchanged) if there was a @ref StructChainingError.
  */
-WGPU_EXPORT void wgpuGetInstanceFeatures(WGPUInstanceFeatures * features) WGPU_FUNCTION_ATTRIBUTE;
+WGPU_EXPORT WGPUStatus wgpuGetInstanceFeatures(WGPUInstanceFeatures * features) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Returns the "procedure address" (function pointer) of the named function.
  * The result must be cast to the appropriate proc pointer type.
@@ -3158,17 +3166,22 @@ WGPU_EXPORT WGPUProc wgpuGetProcAddress(WGPUStringView procName) WGPU_FUNCTION_A
  * This parameter is @ref ReturnedWithOwnership.
  *
  * @returns
- * Return @ref WGPUStatus_Error (and leaves `features` uninitialized) if:
- *
- * - `features` has an invalid struct chain.
+ * Returns @ref WGPUStatus_Error (and leaves `features` unchanged) if there was a @ref StructChainingError.
  */
 WGPU_EXPORT WGPUStatus wgpuAdapterGetFeatures(WGPUAdapter adapter, WGPUSupportedFeatures * features) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * @param info
  * This parameter is @ref ReturnedWithOwnership.
+ *
+ * @returns
+ * Returns @ref WGPUStatus_Error (and leaves `info` unchanged) if there was a @ref StructChainingError.
  */
-WGPU_EXPORT void wgpuAdapterGetInfo(WGPUAdapter adapter, WGPUAdapterInfo * info) WGPU_FUNCTION_ATTRIBUTE;
-WGPU_EXPORT WGPUBool wgpuAdapterGetLimits(WGPUAdapter adapter, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
+WGPU_EXPORT WGPUStatus wgpuAdapterGetInfo(WGPUAdapter adapter, WGPUAdapterInfo * info) WGPU_FUNCTION_ATTRIBUTE;
+/**
+ * @returns
+ * Returns @ref WGPUStatus_Error (and leaves `limits` unchanged) if there was a @ref StructChainingError.
+ */
+WGPU_EXPORT WGPUStatus wgpuAdapterGetLimits(WGPUAdapter adapter, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT WGPUBool wgpuAdapterHasFeature(WGPUAdapter adapter, WGPUFeatureName feature) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT WGPUFuture wgpuAdapterRequestDevice(WGPUAdapter adapter, WGPU_NULLABLE WGPUDeviceDescriptor const * descriptor, WGPURequestDeviceCallbackInfo callbackInfo) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT void wgpuAdapterAddRef(WGPUAdapter adapter) WGPU_FUNCTION_ATTRIBUTE;
@@ -3224,8 +3237,37 @@ WGPU_EXPORT void wgpuBindGroupLayoutRelease(WGPUBindGroupLayout bindGroupLayout)
  * @{
  */
 WGPU_EXPORT void wgpuBufferDestroy(WGPUBuffer buffer) WGPU_FUNCTION_ATTRIBUTE;
+/**
+ * @param offset
+ * Byte offset relative to the beginning of the buffer.
+ *
+ * @param size
+ * Byte size of the range to get. The returned pointer is valid for exactly this many bytes.
+ *
+ * @returns
+ * Returns a const pointer to beginning of the mapped range.
+ * It must not be written; writing to this range causes undefined behavior.
+ * Returns `NULL` with @ref ImplementationDefinedLogging if:
+ *
+ * - There is any content-timeline error as defined in the WebGPU specification for `getMappedRange()` (alignments, overlaps, etc.)
+ */
 WGPU_EXPORT void const * wgpuBufferGetConstMappedRange(WGPUBuffer buffer, size_t offset, size_t size) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT WGPUBufferMapState wgpuBufferGetMapState(WGPUBuffer buffer) WGPU_FUNCTION_ATTRIBUTE;
+/**
+ * @param offset
+ * Byte offset relative to the beginning of the buffer.
+ *
+ * @param size
+ * Byte size of the range to get. The returned pointer is valid for exactly this many bytes.
+ *
+ * @returns
+ * Returns a mutable pointer to beginning of the mapped range.
+ * It may be written, but reading is undefined behavior unless the buffer was also mapped with @ref WGPUMapMode_Read.
+ * Returns `NULL` with @ref ImplementationDefinedLogging if:
+ *
+ * - There is any content-timeline error as defined in the WebGPU specification for `getMappedRange()` (alignments, overlaps, etc.)
+ * - The buffer is not mapped with @ref WGPUMapMode_Write.
+ */
 WGPU_EXPORT void * wgpuBufferGetMappedRange(WGPUBuffer buffer, size_t offset, size_t size) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT uint64_t wgpuBufferGetSize(WGPUBuffer buffer) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT WGPUBufferUsage wgpuBufferGetUsage(WGPUBuffer buffer) WGPU_FUNCTION_ATTRIBUTE;
@@ -3340,12 +3382,14 @@ WGPU_EXPORT void wgpuDeviceDestroy(WGPUDevice device) WGPU_FUNCTION_ATTRIBUTE;
  * This parameter is @ref ReturnedWithOwnership.
  *
  * @returns
- * Return @ref WGPUStatus_Error (and leaves `features` uninitialized) if:
- *
- * - `features` has an invalid struct chain.
+ * Returns @ref WGPUStatus_Error (and leaves `features` unchanged) if there was a @ref StructChainingError.
  */
 WGPU_EXPORT WGPUStatus wgpuDeviceGetFeatures(WGPUDevice device, WGPUSupportedFeatures * features) WGPU_FUNCTION_ATTRIBUTE;
-WGPU_EXPORT WGPUBool wgpuDeviceGetLimits(WGPUDevice device, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
+/**
+ * @returns
+ * Returns @ref WGPUStatus_Error (and leaves `limits` unchanged) if there was a @ref StructChainingError.
+ */
+WGPU_EXPORT WGPUStatus wgpuDeviceGetLimits(WGPUDevice device, WGPULimits * limits) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT WGPUQueue wgpuDeviceGetQueue(WGPUDevice device) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT WGPUBool wgpuDeviceHasFeature(WGPUDevice device, WGPUFeatureName feature) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT WGPUFuture wgpuDevicePopErrorScope(WGPUDevice device, WGPUPopErrorScopeCallbackInfo callbackInfo) WGPU_FUNCTION_ATTRIBUTE;
@@ -3431,6 +3475,10 @@ WGPU_EXPORT void wgpuQuerySetRelease(WGPUQuerySet querySet) WGPU_FUNCTION_ATTRIB
 WGPU_EXPORT WGPUFuture wgpuQueueOnSubmittedWorkDone(WGPUQueue queue, WGPUQueueWorkDoneCallbackInfo callbackInfo) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT void wgpuQueueSetLabel(WGPUQueue queue, WGPUStringView label) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT void wgpuQueueSubmit(WGPUQueue queue, size_t commandCount, WGPUCommandBuffer const * commands) WGPU_FUNCTION_ATTRIBUTE;
+/**
+ * Produces a @ref DeviceError if `size` is not a multiple of 4
+ * (in addition to device-timeline errors defined by the WebGPU specification).
+ */
 WGPU_EXPORT void wgpuQueueWriteBuffer(WGPUQueue queue, WGPUBuffer buffer, uint64_t bufferOffset, void const * data, size_t size) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT void wgpuQueueWriteTexture(WGPUQueue queue, WGPUImageCopyTexture const * destination, void const * data, size_t dataSize, WGPUTextureDataLayout const * dataLayout, WGPUExtent3D const * writeSize) WGPU_FUNCTION_ATTRIBUTE;
 WGPU_EXPORT void wgpuQueueAddRef(WGPUQueue queue) WGPU_FUNCTION_ATTRIBUTE;
@@ -3572,12 +3620,18 @@ WGPU_EXPORT void wgpuSupportedFeaturesFreeMembers(WGPUSupportedFeatures supporte
  */
 /**
  * Configures parameters for rendering to `surface`.
+ * Produces a @ref DeviceError for all content-timeline errors defined by the WebGPU specification
+ * (formats that are not supported by the surface or not enabled on the device).
+ *
  * See @ref Surface-Configuration for more details.
  *
  * @param config
  * The new configuration to use.
+ *
+ * @returns
+ * Returns @ref WGPUStatus_Error if there was a @ref StructChainingError.
  */
-WGPU_EXPORT void wgpuSurfaceConfigure(WGPUSurface surface, WGPUSurfaceConfiguration const * config) WGPU_FUNCTION_ATTRIBUTE;
+WGPU_EXPORT WGPUStatus wgpuSurfaceConfigure(WGPUSurface surface, WGPUSurfaceConfiguration const * config) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Provides information on how `adapter` is able to use `surface`.
  * See @ref Surface-Capabilities for more details.
@@ -3591,11 +3645,13 @@ WGPU_EXPORT void wgpuSurfaceConfigure(WGPUSurface surface, WGPUSurfaceConfigurat
  * This parameter is @ref ReturnedWithOwnership.
  *
  * @returns
- * TODO make this WGPUStatus instead of a boolean.
+ * Returns @ref WGPUStatus_Error (and leaves `capabilities` unchanged) if there was a @ref StructChainingError.
  */
-WGPU_EXPORT WGPUBool wgpuSurfaceGetCapabilities(WGPUSurface surface, WGPUAdapter adapter, WGPUSurfaceCapabilities * capabilities) WGPU_FUNCTION_ATTRIBUTE;
+WGPU_EXPORT WGPUStatus wgpuSurfaceGetCapabilities(WGPUSurface surface, WGPUAdapter adapter, WGPUSurfaceCapabilities * capabilities) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Returns the @ref WGPUTexture to render to `surface` this frame along with metadata on the frame.
+ * Returns `NULL` and @ref WGPUSurfaceGetCurrentTextureStatus_Error if the surface is not configured.
+ *
  * See @ref Surface-Presenting for more details.
  *
  * @param surfaceTexture
@@ -3605,8 +3661,11 @@ WGPU_EXPORT void wgpuSurfaceGetCurrentTexture(WGPUSurface surface, WGPUSurfaceTe
 /**
  * Shows `surface`'s current texture to the user.
  * See @ref Surface-Presenting for more details.
+ *
+ * @returns
+ * Returns @ref WGPUStatus_Error if the surface doesn't have a current texture.
  */
-WGPU_EXPORT void wgpuSurfacePresent(WGPUSurface surface) WGPU_FUNCTION_ATTRIBUTE;
+WGPU_EXPORT WGPUStatus wgpuSurfacePresent(WGPUSurface surface) WGPU_FUNCTION_ATTRIBUTE;
 /**
  * Modifies the label used to refer to `surface`.
  *