Add no_std support (#664)

Co-authored-by: Marijn Suijten <marijn@traverseresearch.nl>

.github/workflows/ci.yml

@@ -16,7 +16,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@1.69.0
-      - run: cargo check -p ash -p ash-rewrite -p ash-window --all-features
+      - name: Check ash, ash-window and ash-rewrite
+        run: cargo check -p ash -p ash-rewrite -p ash-window --all-features
+      - name: Check ash with no_std
+        run: cargo check -p ash --no-default-features
 
   # TODO: add a similar job for the rewrite once that generates code
   generated:

Changelog.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `std` feature. Disabling this feature makes ash `no_std` (#664)
 - Added `Handle::is_null()` to allow checking if a handle is a `NULL` value (#694)
 - Allow building `Entry`/`Instance`/`Device` from handle+fns (see their `from_parts_1_x()` associated functions) (#748)
 - Update Vulkan-Headers to 1.3.281 (#760, #763, #783, #816, #840)

README.md

@@ -19,6 +19,7 @@ A very lightweight wrapper around Vulkan
 - [x] No validation, everything is **unsafe**
 - [x] Generated from `vk.xml`
 - [x] Support for Vulkan `1.1`, `1.2`, `1.3`
+- [x] `no_std` support
 
 ## ⚠️ Semver compatibility warning
 
@@ -193,6 +194,10 @@ The default `loaded` cargo feature will dynamically load the default Vulkan libr
 
 If, on the other hand, your application cannot handle Vulkan being missing at runtime, you can instead enable the `linked` feature, which will link your binary with the Vulkan loader directly and expose the infallible `Entry::linked`.
 
+### Use in `no_std` environments
+
+Ash can be used in `no_std` environments (with `alloc`) by disabling the `std` feature.
+
 ## Example
 
 You can find the examples [here](https://github.com/ash-rs/ash/tree/master/ash-examples).

ash-examples/Cargo.toml

@@ -11,5 +11,5 @@ winit = { version = "0.29", features = ["rwh_06"] }
 # The examples require the validation layers, which means the SDK or
 # equivalent development packages should be present, so we can link
 # directly and benefit from the infallible `Entry` constructor.
-ash = { path = "../ash", default-features = false, features = ["linked", "debug"] }
+ash = { path = "../ash", default-features = false, features = ["linked", "debug", "std"] }
 ash-window = { path = "../ash-window" }

ash-examples/src/bin/texture.rs

@@ -2,7 +2,7 @@
 
 use std::default::Default;
 use std::error::Error;
-use std::ffi::CStr;
+use std::ffi;
 use std::io::Cursor;
 use std::mem;
 use std::os::raw::c_void;
@@ -567,7 +567,7 @@ fn main() -> Result<(), Box<dyn Error>> {
             .create_pipeline_layout(&layout_create_info, None)
             .unwrap();
 
-        let shader_entry_name = CStr::from_bytes_with_nul_unchecked(b"main\0");
+        let shader_entry_name = ffi::CStr::from_bytes_with_nul_unchecked(b"main\0");
         let shader_stage_create_infos = [
             vk::PipelineShaderStageCreateInfo {
                 module: vertex_shader_module,

ash-examples/src/bin/triangle.rs

@@ -2,7 +2,7 @@
 
 use std::default::Default;
 use std::error::Error;
-use std::ffi::CStr;
+use std::ffi;
 use std::io::Cursor;
 use std::mem;
 
@@ -229,7 +229,7 @@ fn main() -> Result<(), Box<dyn Error>> {
             .create_pipeline_layout(&layout_create_info, None)
             .unwrap();
 
-        let shader_entry_name = CStr::from_bytes_with_nul_unchecked(b"main\0");
+        let shader_entry_name = ffi::CStr::from_bytes_with_nul_unchecked(b"main\0");
         let shader_stage_create_infos = [
             vk::PipelineShaderStageCreateInfo {
                 module: vertex_shader_module,

ash-examples/src/lib.rs

@@ -8,16 +8,13 @@
 )]
 
 use std::{
-    borrow::Cow, cell::RefCell, default::Default, error::Error, ffi::CStr, ops::Drop,
-    os::raw::c_char,
+    borrow::Cow, cell::RefCell, default::Default, error::Error, ffi, ops::Drop, os::raw::c_char,
 };
 
 use ash::extensions::{
     ext::debug_utils,
     khr::{surface, swapchain},
 };
-#[cfg(any(target_os = "macos", target_os = "ios"))]
-use ash::vk::khr;
 use ash::{vk, Device, Entry, Instance};
 use winit::{
     event::{ElementState, Event, KeyEvent, WindowEvent},
@@ -106,13 +103,13 @@ unsafe extern "system" fn vulkan_debug_callback(
     let message_id_name = if callback_data.p_message_id_name.is_null() {
         Cow::from("")
     } else {
-        CStr::from_ptr(callback_data.p_message_id_name).to_string_lossy()
+        ffi::CStr::from_ptr(callback_data.p_message_id_name).to_string_lossy()
     };
 
     let message = if callback_data.p_message.is_null() {
         Cow::from("")
     } else {
-        CStr::from_ptr(callback_data.p_message).to_string_lossy()
+        ffi::CStr::from_ptr(callback_data.p_message).to_string_lossy()
     };
 
     println!(
@@ -215,9 +212,9 @@ impl ExampleBase {
                 .build(&event_loop)
                 .unwrap();
             let entry = Entry::linked();
-            let app_name = CStr::from_bytes_with_nul_unchecked(b"VulkanTriangle\0");
+            let app_name = ffi::CStr::from_bytes_with_nul_unchecked(b"VulkanTriangle\0");
 
-            let layer_names = [CStr::from_bytes_with_nul_unchecked(
+            let layer_names = [ffi::CStr::from_bytes_with_nul_unchecked(
                 b"VK_LAYER_KHRONOS_validation\0",
             )];
             let layers_names_raw: Vec<*const c_char> = layer_names
@@ -233,9 +230,9 @@ impl ExampleBase {
 
             #[cfg(any(target_os = "macos", target_os = "ios"))]
             {
-                extension_names.push(khr::portability_enumeration::NAME.as_ptr());
+                extension_names.push(vk::khr::portability_enumeration::NAME.as_ptr());
                 // Enabling this extension is a requirement when using `VK_KHR_portability_subset`
-                extension_names.push(khr::get_physical_device_properties2::NAME.as_ptr());
+                extension_names.push(vk::khr::get_physical_device_properties2::NAME.as_ptr());
             }
 
             let appinfo = vk::ApplicationInfo::default()
@@ -319,7 +316,7 @@ impl ExampleBase {
             let device_extension_names_raw = [
                 swapchain::NAME.as_ptr(),
                 #[cfg(any(target_os = "macos", target_os = "ios"))]
-                khr::portability_subset::NAME.as_ptr(),
+                vk::khr::portability_subset::NAME.as_ptr(),
             ];
             let features = vk::PhysicalDeviceFeatures {
                 shader_clip_distance: 1,

ash-window/Cargo.toml

@@ -19,7 +19,7 @@ edition = "2021"
 rust-version = "1.69.0"
 
 [dependencies]
-ash = { path = "../ash", version = "0.37", default-features = false }
+ash = { path = "../ash", version = "0.37", default-features = false, features = ["std"] }
 raw-window-handle = "0.6"
 
 [target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]

ash/Cargo.toml

@@ -25,13 +25,15 @@ rust-version = "1.69.0"
 libloading = { version = "0.8", optional = true }
 
 [features]
-default = ["loaded", "debug"]
+default = ["loaded", "debug", "std"]
 # Link the Vulkan loader at compile time.
 linked = []
 # Support searching for the Vulkan loader manually at runtime.
-loaded = ["libloading"]
+loaded = ["libloading", "std"]
 # Whether Vulkan structs should implement Debug.
 debug = []
+# Whether the standard library should be required
+std = []
 
 [package.metadata.release]
 no-dev-version = true

ash/src/device.rs

@@ -2,9 +2,10 @@
 use crate::prelude::*;
 use crate::vk;
 use crate::RawPtr;
+use alloc::vec::Vec;
 use core::ffi;
-use std::mem;
-use std::ptr;
+use core::mem;
+use core::ptr;
 
 /// <https://registry.khronos.org/vulkan/specs/1.3-extensions/man/html/VkDevice.html>
 #[derive(Clone)]
@@ -20,9 +21,7 @@ pub struct Device {
 impl Device {
     pub unsafe fn load(instance_fn: &vk::InstanceFnV1_0, device: vk::Device) -> Self {
         Self::load_with(
-            |name: &std::ffi::CStr| {
-                mem::transmute((instance_fn.get_device_proc_addr)(device, name.as_ptr()))
-            },
+            |name| mem::transmute((instance_fn.get_device_proc_addr)(device, name.as_ptr())),
             device,
         )
     }

ash/src/entry.rs

@@ -2,17 +2,11 @@ use crate::instance::Instance;
 use crate::prelude::*;
 use crate::vk;
 use crate::RawPtr;
-use std::error::Error;
-use std::ffi::CStr;
-#[cfg(feature = "loaded")]
-use std::ffi::OsStr;
-use std::fmt;
-use std::mem;
-use std::os::raw::c_char;
-use std::os::raw::c_void;
-use std::ptr;
-#[cfg(feature = "loaded")]
-use std::sync::Arc;
+use alloc::vec::Vec;
+use core::ffi;
+use core::fmt;
+use core::mem;
+use core::ptr;
 
 #[cfg(feature = "loaded")]
 use libloading::Library;
@@ -24,7 +18,7 @@ pub struct Entry {
     entry_fn_1_0: vk::EntryFnV1_0,
     entry_fn_1_1: vk::EntryFnV1_1,
     #[cfg(feature = "loaded")]
-    _lib_guard: Option<Arc<Library>>,
+    _lib_guard: Option<alloc::sync::Arc<Library>>,
 }
 
 /// Vulkan core 1.0
@@ -134,10 +128,10 @@ impl Entry {
     /// may be called after it is [dropped][drop()].
     #[cfg(feature = "loaded")]
     #[cfg_attr(docsrs, doc(cfg(feature = "loaded")))]
-    pub unsafe fn load_from(path: impl AsRef<OsStr>) -> Result<Self, LoadingError> {
+    pub unsafe fn load_from(path: impl AsRef<std::ffi::OsStr>) -> Result<Self, LoadingError> {
         let lib = Library::new(path)
             .map_err(LoadingError::LibraryLoadFailure)
-            .map(Arc::new)?;
+            .map(alloc::sync::Arc::new)?;
 
         let static_fn = vk::StaticFn::load_checked(|name| {
             lib.get(name.to_bytes_with_nul())
@@ -158,7 +152,7 @@ impl Entry {
     /// `static_fn` must contain valid function pointers that comply with the semantics specified
     /// by Vulkan 1.0, which must remain valid for at least the lifetime of the returned [`Entry`].
     pub unsafe fn from_static_fn(static_fn: vk::StaticFn) -> Self {
-        let load_fn = move |name: &CStr| {
+        let load_fn = move |name: &ffi::CStr| {
             mem::transmute((static_fn.get_instance_proc_addr)(
                 vk::Instance::null(),
                 name.as_ptr(),
@@ -220,7 +214,7 @@ impl Entry {
     #[inline]
     pub unsafe fn try_enumerate_instance_version(&self) -> VkResult<Option<u32>> {
         let enumerate_instance_version: Option<vk::PFN_vkEnumerateInstanceVersion> = {
-            let name = CStr::from_bytes_with_nul_unchecked(b"vkEnumerateInstanceVersion\0");
+            let name = ffi::CStr::from_bytes_with_nul_unchecked(b"vkEnumerateInstanceVersion\0");
             mem::transmute((self.static_fn.get_instance_proc_addr)(
                 vk::Instance::null(),
                 name.as_ptr(),
@@ -275,7 +269,7 @@ impl Entry {
     #[inline]
     pub unsafe fn enumerate_instance_extension_properties(
         &self,
-        layer_name: Option<&CStr>,
+        layer_name: Option<&ffi::CStr>,
     ) -> VkResult<Vec<vk::ExtensionProperties>> {
         read_into_uninitialized_vector(|count, data| {
             (self.entry_fn_1_0.enumerate_instance_extension_properties)(
@@ -291,7 +285,7 @@ impl Entry {
     pub unsafe fn get_instance_proc_addr(
         &self,
         instance: vk::Instance,
-        p_name: *const c_char,
+        p_name: *const ffi::c_char,
     ) -> vk::PFN_vkVoidFunction {
         (self.static_fn.get_instance_proc_addr)(instance, p_name)
     }
@@ -328,11 +322,11 @@ impl Default for Entry {
 impl vk::StaticFn {
     pub fn load_checked<F>(mut _f: F) -> Result<Self, MissingEntryPoint>
     where
-        F: FnMut(&CStr) -> *const c_void,
+        F: FnMut(&ffi::CStr) -> *const ffi::c_void,
     {
         Ok(Self {
             get_instance_proc_addr: unsafe {
-                let cname = CStr::from_bytes_with_nul_unchecked(b"vkGetInstanceProcAddr\0");
+                let cname = ffi::CStr::from_bytes_with_nul_unchecked(b"vkGetInstanceProcAddr\0");
                 let val = _f(cname);
                 if val.is_null() {
                     return Err(MissingEntryPoint);
@@ -351,12 +345,15 @@ impl fmt::Display for MissingEntryPoint {
         write!(f, "Cannot load `vkGetInstanceProcAddr` symbol from library")
     }
 }
-impl Error for MissingEntryPoint {}
+#[cfg(feature = "std")] // TODO: implement when error_in_core is stabilized
+impl std::error::Error for MissingEntryPoint {}
 
 #[cfg(feature = "linked")]
 extern "system" {
-    fn vkGetInstanceProcAddr(instance: vk::Instance, name: *const c_char)
-        -> vk::PFN_vkVoidFunction;
+    fn vkGetInstanceProcAddr(
+        instance: vk::Instance,
+        name: *const ffi::c_char,
+    ) -> vk::PFN_vkVoidFunction;
 }
 
 #[cfg(feature = "loaded")]
@@ -380,8 +377,9 @@ mod loaded {
         }
     }
 
-    impl Error for LoadingError {
-        fn source(&self) -> Option<&(dyn Error + 'static)> {
+    #[cfg(feature = "std")]
+    impl std::error::Error for LoadingError {
+        fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
             Some(match self {
                 Self::LibraryLoadFailure(err) => err,
                 Self::MissingEntryPoint(err) => err,

ash/src/extensions/amd/buffer_marker.rs

@@ -1,10 +1,10 @@
 //! <https://registry.khronos.org/vulkan/specs/1.3-extensions/man/html/VK_AMD_buffer_marker.html>
 
 use crate::vk;
-use std::ffi::CStr;
-use std::mem;
+use core::ffi;
+use core::mem;
 
-pub const NAME: &CStr = vk::amd::buffer_marker::NAME;
+pub const NAME: &ffi::CStr = vk::amd::buffer_marker::NAME;
 
 #[derive(Clone)]
 pub struct Device {

ash/src/extensions/amd/shader_info.rs

@@ -2,10 +2,11 @@
 
 use crate::prelude::*;
 use crate::vk;
-use std::ffi::CStr;
-use std::mem;
+use alloc::vec::Vec;
+use core::ffi;
+use core::mem;
 
-pub const NAME: &CStr = vk::amd::shader_info::NAME;
+pub const NAME: &ffi::CStr = vk::amd::shader_info::NAME;
 
 #[derive(Clone)]
 pub struct Device {

ash/src/extensions/amdx/shader_enqueue.rs

@@ -3,10 +3,11 @@
 use crate::prelude::*;
 use crate::vk;
 use crate::RawPtr;
-use std::ffi::CStr;
-use std::mem;
+use alloc::vec::Vec;
+use core::ffi;
+use core::mem;
 
-pub const NAME: &CStr = vk::amdx::shader_enqueue::NAME;
+pub const NAME: &ffi::CStr = vk::amdx::shader_enqueue::NAME;
 
 #[derive(Clone)]
 pub struct Device {

ash/src/extensions/android/external_memory_android_hardware_buffer.rs

@@ -2,10 +2,10 @@
 
 use crate::prelude::*;
 use crate::vk;
-use std::ffi::CStr;
-use std::mem;
+use core::ffi;
+use core::mem;
 
-pub const NAME: &CStr = vk::android::external_memory_android_hardware_buffer::NAME;
+pub const NAME: &ffi::CStr = vk::android::external_memory_android_hardware_buffer::NAME;
 
 #[derive(Clone)]
 pub struct Device {

ash/src/extensions/ext/acquire_drm_display.rs

@@ -2,10 +2,10 @@
 
 use crate::prelude::*;
 use crate::vk;
-use std::ffi::CStr;
-use std::mem;
+use core::ffi;
+use core::mem;
 
-pub const NAME: &CStr = vk::ext::acquire_drm_display::NAME;
+pub const NAME: &ffi::CStr = vk::ext::acquire_drm_display::NAME;
 
 #[derive(Clone)]
 pub struct Instance {