Allow Naga spv-in and spv-out in no_std (#7760)

Co-authored-by: Connor Fitzgerald <connorwadefitzgerald@gmail.com>

.github/workflows/ci.yml

@@ -296,7 +296,7 @@ jobs:
 
           # Check with all compatible features
           cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-types --no-default-features --features strict_asserts,fragile-send-sync-non-atomic-wasm,serde,counters
-          cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p naga --no-default-features --features dot-out
+          cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p naga --no-default-features --features dot-out,spv-in,spv-out
           cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-hal --no-default-features --features fragile-send-sync-non-atomic-wasm
           cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu --no-default-features --features serde
 

naga-cli/Cargo.toml

@@ -38,6 +38,7 @@ naga = { workspace = true, features = [
     "deserialize",
     "termcolor",
     "stderr",
+    "fs",
 ] }
 
 bincode.workspace = true

naga-cli/src/bin/naga.rs

@@ -424,7 +424,7 @@ fn run() -> anyhow::Result<()> {
     params.spv_in = naga::front::spv::Options {
         adjust_coordinate_space: !args.keep_coordinate_space,
         strict_capabilities: false,
-        block_ctx_dump_prefix: args.block_ctx_dir.clone().map(std::path::PathBuf::from),
+        block_ctx_dump_prefix: args.block_ctx_dir.clone().map(Into::into),
     };
 
     params.entry_point.clone_from(&args.entry_point);
@@ -486,7 +486,7 @@ fn run() -> anyhow::Result<()> {
                 .set(naga::back::spv::WriterFlags::DEBUG, true);
             params.spv_out.debug_info = Some(naga::back::spv::DebugInfo {
                 source_code: input_text,
-                file_name: input_path,
+                file_name: input_path.into(),
                 language,
             })
         } else {

naga/Cargo.toml

@@ -23,7 +23,6 @@ default = []
 dot-out = []
 glsl-in = ["dep:pp-rs"]
 glsl-out = []
-std = []
 
 ## Enables outputting to the Metal Shading Language (MSL).
 ##
@@ -79,6 +78,9 @@ termcolor = ["codespan-reporting/termcolor"]
 ## Enables writing output to stderr.
 stderr = ["codespan-reporting/std"]
 
+## Enables integration with the underlying filesystem.
+fs = []
+
 [dependencies]
 arbitrary = { workspace = true, features = ["derive"], optional = true }
 arrayvec.workspace = true

naga/build.rs

@@ -6,7 +6,7 @@ fn main() {
         msl_out: { any(feature = "msl-out", all(target_vendor = "apple", feature = "msl-out-if-target-apple")) },
         spv_out: { feature = "spv-out" },
         wgsl_out: { feature = "wgsl-out" },
-        std: { any(test, spv_out, feature = "spv-in", feature = "wgsl-in", feature = "stderr") },
+        std: { any(test, feature = "wgsl-in", feature = "stderr", feature = "fs") },
         no_std: { not(std) },
     }
 }

naga/src/as_diagnostic_file_path.rs

@@ -1,79 +0,0 @@
-//! [`AsDiagnosticFilePath`] and its supporting items.
-
-use alloc::borrow::Cow;
-
-#[cfg(feature = "std")]
-use std::path::Path;
-
-#[cfg(not(feature = "std"))]
-use alloc::string::String;
-
-mod sealed {
-    pub trait Sealed {}
-}
-
-/// A trait that abstracts over types accepted for conversion to the most
-/// featureful path representation possible; that is:
-///
-/// - When `no_std` is active, this is implemented for [`String`], [`str`], and [`Cow`] (i.e.,
-///   `Cow<'_, str>`).
-/// - Otherwise, types that implement `AsRef<Path>` (to extract a `&Path`).
-///
-/// This type is used as the type bounds for various diagnostic rendering methods, i.e.,
-/// [`WithSpan::emit_to_string_with_path`](crate::span::WithSpan::emit_to_string_with_path).
-///
-/// [`String`]: alloc::string::String
-pub trait AsDiagnosticFilePath: sealed::Sealed {
-    fn to_string_lossy(&self) -> Cow<'_, str>;
-}
-
-#[cfg(feature = "std")]
-impl<T: AsRef<Path> + ?Sized> AsDiagnosticFilePath for T {
-    fn to_string_lossy(&self) -> Cow<'_, str> {
-        self.as_ref().to_string_lossy()
-    }
-}
-
-#[cfg(feature = "std")]
-impl<T: AsRef<Path> + ?Sized> sealed::Sealed for T {}
-
-#[cfg(not(feature = "std"))]
-impl AsDiagnosticFilePath for String {
-    fn to_string_lossy(&self) -> Cow<'_, str> {
-        Cow::Borrowed(self.as_str())
-    }
-}
-
-#[cfg(not(feature = "std"))]
-impl sealed::Sealed for String {}
-
-#[cfg(not(feature = "std"))]
-impl AsDiagnosticFilePath for str {
-    fn to_string_lossy(&self) -> Cow<'_, str> {
-        Cow::Borrowed(self)
-    }
-}
-
-#[cfg(not(feature = "std"))]
-impl sealed::Sealed for str {}
-
-#[cfg(not(feature = "std"))]
-impl AsDiagnosticFilePath for Cow<'_, str> {
-    fn to_string_lossy(&self) -> Cow<'_, str> {
-        use core::borrow::Borrow;
-        Cow::Borrowed(self.borrow())
-    }
-}
-
-#[cfg(not(feature = "std"))]
-impl sealed::Sealed for Cow<'_, str> {}
-
-#[cfg(not(feature = "std"))]
-impl<T: AsDiagnosticFilePath + ?Sized> AsDiagnosticFilePath for &T {
-    fn to_string_lossy(&self) -> Cow<'_, str> {
-        (*self).to_string_lossy()
-    }
-}
-
-#[cfg(not(feature = "std"))]
-impl<T: AsDiagnosticFilePath + ?Sized> sealed::Sealed for &T {}

naga/src/back/spv/mod.rs

@@ -25,6 +25,7 @@ use spirv::Word;
 use thiserror::Error;
 
 use crate::arena::{Handle, HandleVec};
+use crate::path_like::PathLikeRef;
 use crate::proc::{BoundsCheckPolicies, TypeResolution};
 
 #[derive(Clone)]
@@ -92,7 +93,7 @@ impl IdGenerator {
 #[derive(Debug, Clone)]
 pub struct DebugInfo<'a> {
     pub source_code: &'a str,
-    pub file_name: &'a std::path::Path,
+    pub file_name: PathLikeRef<'a>,
     pub language: SourceLanguage,
 }
 

naga/src/back/spv/writer.rs

@@ -1,8 +1,4 @@
-use alloc::{
-    string::{String, ToString},
-    vec,
-    vec::Vec,
-};
+use alloc::{string::String, vec, vec::Vec};
 
 use hashbrown::hash_map::Entry;
 use spirv::Word;
@@ -18,6 +14,7 @@ use super::{
 use crate::{
     arena::{Handle, HandleVec, UniqueArena},
     back::spv::{BindingInfo, WrappedFunction},
+    path_like::PathLike,
     proc::{Alignment, TypeResolution},
     valid::{FunctionInfo, ModuleInfo},
 };
@@ -2415,7 +2412,7 @@ impl Writer {
             if let Some(debug_info) = debug_info.as_ref() {
                 let source_file_id = self.id_gen.next();
                 self.debugs.push(Instruction::string(
-                    &debug_info.file_name.display().to_string(),
+                    &debug_info.file_name.to_string_lossy(),
                     source_file_id,
                 ));
 

naga/src/front/spv/function.rs

@@ -169,10 +169,18 @@ impl<I: Iterator<Item = u32>> super::Frontend<I> {
                 Some(ep) => format!("block_ctx.{:?}-{}.txt", ep.stage, ep.name),
                 None => format!("block_ctx.Fun-{}.txt", function_index),
             };
-            let dest = prefix.join(dump_suffix);
-            let dump = format!("{block_ctx:#?}");
-            if let Err(e) = std::fs::write(&dest, dump) {
-                log::error!("Unable to dump the block context into {:?}: {}", dest, e);
+
+            cfg_if::cfg_if! {
+                if #[cfg(feature = "fs")] {
+                    let prefix: &std::path::Path = prefix.as_ref();
+                    let dest = prefix.join(dump_suffix);
+                    let dump = format!("{block_ctx:#?}");
+                    if let Err(e) = std::fs::write(&dest, dump) {
+                        log::error!("Unable to dump the block context into {:?}: {}", dest, e);
+                    }
+                } else {
+                    log::error!("Unable to dump the block context into {:?}/{}: file system integration was not enabled with the `fs` feature", prefix, dump_suffix);
+                }
             }
         }
 

naga/src/front/spv/mod.rs

@@ -37,7 +37,6 @@ pub use error::Error;
 
 use alloc::{borrow::ToOwned, format, string::String, vec, vec::Vec};
 use core::{convert::TryInto, mem, num::NonZeroU32};
-use std::path::PathBuf;
 
 use half::f16;
 use petgraph::graphmap::GraphMap;
@@ -45,6 +44,7 @@ use petgraph::graphmap::GraphMap;
 use super::atomic_upgrade::Upgrades;
 use crate::{
     arena::{Arena, Handle, UniqueArena},
+    path_like::PathLikeOwned,
     proc::{Alignment, Layouter},
     FastHashMap, FastHashSet, FastIndexMap,
 };
@@ -381,7 +381,7 @@ pub struct Options {
     pub adjust_coordinate_space: bool,
     /// Only allow shaders with the known set of capabilities.
     pub strict_capabilities: bool,
-    pub block_ctx_dump_prefix: Option<PathBuf>,
+    pub block_ctx_dump_prefix: Option<PathLikeOwned>,
 }
 
 impl Default for Options {

naga/src/lib.rs

@@ -106,7 +106,6 @@ extern crate std;
 extern crate alloc;
 
 mod arena;
-mod as_diagnostic_file_path;
 pub mod back;
 pub mod common;
 pub mod compact;
@@ -116,6 +115,7 @@ pub mod front;
 pub mod ir;
 pub mod keywords;
 mod non_max_u32;
+mod path_like;
 pub mod proc;
 mod racy_lock;
 mod span;

naga/src/path_like.rs

@@ -0,0 +1,238 @@
+//! [`PathLike`] and its supporting items, such as [`PathLikeRef`] and [`PathLikeOwned`].
+//! This trait and these types provide a common denominator API for `Path`-like
+//! types and operations in `std` and `no_std` contexts.
+//!
+//! # Usage
+//!
+//! - Store a [`PathLikeRef<'a>`] instead of a `&'a Path` in structs and enums.
+//! - Store a [`PathLikeOwned`] instead of a `PathBuf` in structs and enums.
+//! - Accept `impl PathLike` instead of `impl AsRef<Path>` for methods which directly
+//!   work with `Path`-like values.
+//! - Accept `Into<PathLikeRef<'_>>` and/or `Into<PathLikeOwned>` in methods which
+//!   will store a `Path`-like value.
+
+use alloc::{borrow::Cow, string::String};
+use core::fmt;
+
+mod sealed {
+    /// Seal for [`PathLike`](super::PathLike).
+    pub trait Sealed {}
+}
+
+/// A trait that abstracts over types accepted for conversion to the most
+/// featureful path representation possible; that is:
+///
+/// - When `no_std` is active, this is implemented for:
+///   - [`str`],
+///   - [`String`],
+///   - [`Cow<'_, str>`], and
+///   - [`PathLikeRef`]
+/// - Otherwise, types that implement `AsRef<Path>` (to extract a `&Path`).
+///
+/// This type is used as the type bounds for various diagnostic rendering methods, i.e.,
+/// [`WithSpan::emit_to_string_with_path`](crate::span::WithSpan::emit_to_string_with_path).
+pub trait PathLike: sealed::Sealed {
+    fn to_string_lossy(&self) -> Cow<'_, str>;
+}
+
+/// Abstraction over `Path` which falls back to [`str`] for `no_std` compatibility.
+///
+/// This type should be used for _storing_ a reference to a [`PathLike`].
+/// Functions which accept a `Path` should prefer to use `impl PathLike`
+/// or `impl Into<PathLikeRef<'_>>`.
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct PathLikeRef<'a>(&'a path_like_impls::PathInner);
+
+impl fmt::Debug for PathLikeRef<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self.0, f)
+    }
+}
+
+impl<'a> From<&'a str> for PathLikeRef<'a> {
+    fn from(value: &'a str) -> Self {
+        cfg_if::cfg_if! {
+            if #[cfg(std)] {
+                Self(std::path::Path::new(value))
+            } else {
+                Self(value)
+            }
+        }
+    }
+}
+
+/// Abstraction over `PathBuf` which falls back to [`String`] for `no_std` compatibility.
+///
+/// This type should be used for _storing_ an owned [`PathLike`].
+/// Functions which accept a `PathBuf` should prefer to use `impl PathLike`
+/// or `impl Into<PathLikeOwned>`.
+#[derive(Clone, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct PathLikeOwned(<path_like_impls::PathInner as alloc::borrow::ToOwned>::Owned);
+
+impl fmt::Debug for PathLikeOwned {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.0, f)
+    }
+}
+
+impl From<String> for PathLikeOwned {
+    fn from(value: String) -> Self {
+        cfg_if::cfg_if! {
+            if #[cfg(std)] {
+                Self(value.into())
+            } else {
+                Self(value)
+            }
+        }
+    }
+}
+
+#[cfg(std)]
+mod path_like_impls {
+    //! Implementations of [`PathLike`] within an `std` context.
+    //!
+    //! Since `std` is available, we blanket implement [`PathLike`] for all types
+    //! implementing [`AsRef<Path>`].
+
+    use alloc::borrow::Cow;
+    use std::path::Path;
+
+    use super::{sealed, PathLike};
+
+    pub(super) type PathInner = Path;
+
+    impl<T: AsRef<Path> + ?Sized> PathLike for T {
+        fn to_string_lossy(&self) -> Cow<'_, str> {
+            self.as_ref().to_string_lossy()
+        }
+    }
+
+    impl<T: AsRef<Path> + ?Sized> sealed::Sealed for T {}
+}
+
+#[cfg(no_std)]
+mod path_like_impls {
+    //! Implementations of [`PathLike`] within a `no_std` context.
+    //!
+    //! Without `std`, we cannot blanket implement on [`AsRef<Path>`].
+    //! Instead, we manually implement for a subset of types which are known
+    //! to implement [`AsRef<Path>`] when `std` is available.
+    //!
+    //! Implementing [`PathLike`] for a type which does _not_ implement [`AsRef<Path>`]
+    //! with `std` enabled breaks the additive requirement of Cargo features.
+
+    use alloc::{borrow::Cow, string::String};
+    use core::borrow::Borrow;
+
+    use super::{sealed, PathLike, PathLikeOwned, PathLikeRef};
+
+    pub(super) type PathInner = str;
+
+    impl PathLike for String {
+        fn to_string_lossy(&self) -> Cow<'_, str> {
+            Cow::Borrowed(self.as_str())
+        }
+    }
+
+    impl sealed::Sealed for String {}
+
+    impl PathLike for str {
+        fn to_string_lossy(&self) -> Cow<'_, str> {
+            Cow::Borrowed(self)
+        }
+    }
+
+    impl sealed::Sealed for str {}
+
+    impl PathLike for Cow<'_, str> {
+        fn to_string_lossy(&self) -> Cow<'_, str> {
+            Cow::Borrowed(self.borrow())
+        }
+    }
+
+    impl sealed::Sealed for Cow<'_, str> {}
+
+    impl<T: PathLike + ?Sized> PathLike for &T {
+        fn to_string_lossy(&self) -> Cow<'_, str> {
+            (*self).to_string_lossy()
+        }
+    }
+
+    impl<T: PathLike + ?Sized> sealed::Sealed for &T {}
+
+    impl PathLike for PathLikeRef<'_> {
+        fn to_string_lossy(&self) -> Cow<'_, str> {
+            Cow::Borrowed(self.0)
+        }
+    }
+
+    impl sealed::Sealed for PathLikeRef<'_> {}
+
+    impl PathLike for PathLikeOwned {
+        fn to_string_lossy(&self) -> Cow<'_, str> {
+            Cow::Borrowed(self.0.borrow())
+        }
+    }
+
+    impl sealed::Sealed for PathLikeOwned {}
+}
+
+#[cfg(std)]
+mod path_like_owned_std_impls {
+    //! Traits which can only be implemented for [`PathLikeOwned`] with `std`.
+
+    use std::path::{Path, PathBuf};
+
+    use super::PathLikeOwned;
+
+    impl AsRef<Path> for PathLikeOwned {
+        fn as_ref(&self) -> &Path {
+            self.0.as_ref()
+        }
+    }
+
+    impl From<PathBuf> for PathLikeOwned {
+        fn from(value: PathBuf) -> Self {
+            Self(value)
+        }
+    }
+
+    impl From<PathLikeOwned> for PathBuf {
+        fn from(value: PathLikeOwned) -> Self {
+            value.0
+        }
+    }
+
+    impl AsRef<PathBuf> for PathLikeOwned {
+        fn as_ref(&self) -> &PathBuf {
+            &self.0
+        }
+    }
+}
+
+#[cfg(std)]
+mod path_like_ref_std_impls {
+    //! Traits which can only be implemented for [`PathLikeRef`] with `std`.
+
+    use std::path::Path;
+
+    use super::PathLikeRef;
+
+    impl AsRef<Path> for PathLikeRef<'_> {
+        fn as_ref(&self) -> &Path {
+            self.0
+        }
+    }
+
+    impl<'a> From<&'a Path> for PathLikeRef<'a> {
+        fn from(value: &'a Path) -> Self {
+            Self(value)
+        }
+    }
+
+    impl<'a> From<PathLikeRef<'a>> for &'a Path {
+        fn from(value: PathLikeRef<'a>) -> Self {
+            value.0
+        }
+    }
+}

naga/src/span.rs

@@ -6,7 +6,7 @@ use alloc::{
 };
 use core::{error::Error, fmt, ops::Range};
 
-use crate::{as_diagnostic_file_path::AsDiagnosticFilePath, Arena, Handle, UniqueArena};
+use crate::{path_like::PathLike, Arena, Handle, UniqueArena};
 
 /// A source code span, used for error reporting.
 #[derive(Clone, Copy, Debug, PartialEq, Default)]
@@ -286,7 +286,7 @@ impl<E> WithSpan<E> {
     pub fn emit_to_stderr_with_path<P>(&self, source: &str, path: P)
     where
         E: Error,
-        P: AsDiagnosticFilePath,
+        P: PathLike,
     {
         use codespan_reporting::{files, term};
 
@@ -318,7 +318,7 @@ impl<E> WithSpan<E> {
     pub fn emit_to_string_with_path<P>(&self, source: &str, path: P) -> String
     where
         E: Error,
-        P: AsDiagnosticFilePath,
+        P: PathLike,
     {
         use codespan_reporting::{files, term};
 

naga/tests/naga/snapshots.rs

@@ -476,7 +476,7 @@ fn check_targets(input: &Input, module: &mut naga::Module, source_code: Option<&
             if let Some(source_code) = source_code {
                 debug_info = Some(naga::back::spv::DebugInfo {
                     source_code,
-                    file_name: name,
+                    file_name: name.as_path().into(),
                     // wgpu#6266: we technically know all the information here to
                     // produce the valid language but it's not too important for
                     // validation purposes
@@ -883,7 +883,7 @@ fn convert_snapshots_spv() {
             &naga::front::spv::Options {
                 adjust_coordinate_space,
                 strict_capabilities: true,
-                block_ctx_dump_prefix: None,
+                ..Default::default()
             },
         )
         .unwrap();

wgpu-hal/src/vulkan/device.rs

@@ -885,7 +885,7 @@ impl super::Device {
                     if let Some(ref debug) = naga_shader.debug_source {
                         temp_options.debug_info = Some(naga::back::spv::DebugInfo {
                             source_code: &debug.source_code,
-                            file_name: debug.file_name.as_ref().as_ref(),
+                            file_name: debug.file_name.as_ref().into(),
                             language: naga::back::spv::SourceLanguage::WGSL,
                         })
                     }
@@ -1884,7 +1884,7 @@ impl crate::Device for super::Device {
                         .as_ref()
                         .map(|d| naga::back::spv::DebugInfo {
                             source_code: d.source_code.as_ref(),
-                            file_name: d.file_name.as_ref().as_ref(),
+                            file_name: d.file_name.as_ref().into(),
                             language: naga::back::spv::SourceLanguage::WGSL,
                         });
                 if !desc.runtime_checks.bounds_checks {