add spirv-unknown-wgsl target via naga

.github/workflows/ci.yaml

@@ -119,9 +119,17 @@ jobs:
   compiletest:
     name: Compiletest
     strategy:
+      fail-fast: false
       matrix:
         os: [ ubuntu-24.04, windows-2022, macOS-latest ]
+        target_env: [ "vulkan1.1,vulkan1.2,vulkan1.3,vulkan1.4" ]
+        experimental: [ false ]
+        include:
+          - os: ubuntu-24.04
+            target_env: wgsl
+            experimental: true
     runs-on: ${{ matrix.os }}
+    continue-on-error: ${{ matrix.experimental }}
     steps:
       - uses: actions/checkout@v4
       - name: Install Vulkan SDK
@@ -134,7 +142,7 @@ jobs:
       - name: cargo fetch --locked
         run: cargo fetch --locked --target $TARGET
       - name: compiletest
-        run: cargo run -p compiletests --release --no-default-features --features "use-installed-tools" -- --target-env vulkan1.1,vulkan1.2,vulkan1.3,vulkan1.4,spv1.3
+        run: cargo run -p compiletests --release --no-default-features --features "use-installed-tools" -- --target-env ${{ matrix.target_env }}
 
   difftest:
     name: Difftest

crates/rustc_codegen_spirv-target-specs/src/include_str.rs

@@ -59,6 +59,9 @@ impl SpirvTargetEnv {
             SpirvTargetEnv::Vulkan_1_4 => {
                 include_str!("../target-specs/spirv-unknown-vulkan1.4.json")
             }
+            SpirvTargetEnv::Wgsl => {
+                include_str!("../target-specs/spirv-unknown-wgsl.json")
+            }
         }
     }
 }

crates/rustc_codegen_spirv-target-specs/src/lib.rs

@@ -60,6 +60,8 @@ pub enum SpirvTargetEnv {
     Vulkan_1_3,
     #[strum(to_string = "vulkan1.4")]
     Vulkan_1_4,
+    #[strum(to_string = "wgsl")]
+    Wgsl,
 }
 
 #[derive(Clone, Error, Eq, PartialEq)]

crates/rustc_codegen_spirv-target-specs/target-specs/spirv-unknown-wgsl.json

@@ -0,0 +1,26 @@
+{
+  "allows-weak-linkage": false,
+  "arch": "spirv",
+  "crt-objects-fallback": "false",
+  "crt-static-allows-dylibs": true,
+  "data-layout": "e-m:e-p:32:32:32-i64:64-n8:16:32:64",
+  "dll-prefix": "",
+  "dll-suffix": ".spv.json",
+  "dynamic-linking": true,
+  "emit-debug-gdb-scripts": false,
+  "env": "wgsl",
+  "linker-flavor": "unix",
+  "linker-is-gnu": false,
+  "llvm-target": "spirv-unknown-wgsl",
+  "main-needs-argc-argv": false,
+  "metadata": {
+    "description": null,
+    "host_tools": null,
+    "std": null,
+    "tier": null
+  },
+  "os": "unknown",
+  "panic-strategy": "abort",
+  "simd-types-indirect": false,
+  "target-pointer-width": "32"
+}

crates/rustc_codegen_spirv/Cargo.toml

@@ -20,15 +20,16 @@ crate-type = ["dylib"]
 default = ["use-compiled-tools"]
 # If enabled, uses spirv-tools binaries installed in PATH, instead of
 # compiling and linking the spirv-tools C++ code
-use-installed-tools = ["spirv-tools/use-installed-tools"]
+use-installed-tools = ["spirv-tools/use-installed-tools", "naga"]
 # If enabled will compile and link the C++ code for the spirv tools, the compiled
 # version is preferred if both this and `use-installed-tools` are enabled
-use-compiled-tools = ["spirv-tools/use-compiled-tools"]
+use-compiled-tools = ["spirv-tools/use-compiled-tools", "naga"]
 # If enabled, this will not check whether the current rustc version is set to the
 # appropriate channel. rustc_cogeden_spirv requires a specific nightly version,
 # and will likely produce compile errors when built against a different toolchain.
 # Enable this feature to be able to experiment with other versions.
 skip-toolchain-check = []
+naga = ["dep:naga"]
 
 [dependencies]
 # HACK(eddyb) these only exist to unify features across dependency trees,
@@ -60,6 +61,7 @@ itertools = "0.10.5"
 tracing.workspace = true
 tracing-subscriber.workspace = true
 tracing-tree = "0.3.0"
+naga = { version = "25.0.1", features = ["spv-in", "wgsl-out"], optional = true }
 
 # required for cargo gpu to resolve the needed target specs
 rustc_codegen_spirv-target-specs.workspace = true

crates/rustc_codegen_spirv/src/lib.rs

@@ -129,6 +129,7 @@ mod custom_decorations;
 mod custom_insts;
 mod link;
 mod linker;
+mod naga_transpile;
 mod spirv_type;
 mod spirv_type_constraints;
 mod symbols;

crates/rustc_codegen_spirv/src/link.rs

@@ -2,6 +2,7 @@
 use crate::maybe_pqp_cg_ssa as rustc_codegen_ssa;
 
 use crate::codegen_cx::{CodegenArgs, SpirvMetadata};
+use crate::naga_transpile::should_transpile;
 use crate::{SpirvCodegenBackend, SpirvModuleBuffer, SpirvThinBuffer, linker};
 use ar::{Archive, GnuBuilder, Header};
 use rspirv::binary::Assemble;
@@ -311,6 +312,10 @@ fn post_link_single_module(
 
         drop(save_modules_timer);
     }
+
+    if let Ok(Some(transpile)) = should_transpile(sess) {
+        transpile(sess, cg_args, &spv_binary, out_filename).ok();
+    }
 }
 
 fn do_spirv_opt(

crates/rustc_codegen_spirv/src/naga_transpile.rs

@@ -0,0 +1,85 @@
+use crate::codegen_cx::CodegenArgs;
+use rustc_codegen_spirv_target_specs::SpirvTargetEnv;
+use rustc_session::Session;
+use rustc_span::ErrorGuaranteed;
+use std::path::Path;
+
+pub type NagaTranspile = fn(
+    sess: &Session,
+    cg_args: &CodegenArgs,
+    spv_binary: &[u32],
+    out_filename: &Path,
+) -> Result<(), ErrorGuaranteed>;
+
+pub fn should_transpile(sess: &Session) -> Result<Option<NagaTranspile>, ErrorGuaranteed> {
+    let target = SpirvTargetEnv::parse_triple(sess.opts.target_triple.tuple())
+        .expect("parsing should fail earlier");
+    let result: Result<Option<NagaTranspile>, ()> = match target {
+        #[cfg(feature = "naga")]
+        SpirvTargetEnv::Wgsl => Ok(Some(transpile::wgsl_transpile)),
+        #[cfg(not(feature = "naga"))]
+        SpirvTargetEnv::Wgsl => Err(()),
+        _ => Ok(None),
+    };
+    result.map_err(|_e| {
+        sess.dcx().err(format!(
+            "Target {} requires feature \"naga\" on rustc_codegen_spirv",
+            target.target_triple()
+        ))
+    })
+}
+
+#[cfg(feature = "naga")]
+mod transpile {
+    use crate::codegen_cx::CodegenArgs;
+    use naga::error::ShaderError;
+    use naga::valid::Capabilities;
+    use rustc_session::Session;
+    use rustc_span::ErrorGuaranteed;
+    use std::path::Path;
+
+    pub fn wgsl_transpile(
+        sess: &Session,
+        _cg_args: &CodegenArgs,
+        spv_binary: &[u32],
+        out_filename: &Path,
+    ) -> Result<(), ErrorGuaranteed> {
+        // these should be params via spirv-builder
+        let opts = naga::front::spv::Options::default();
+        let capabilities = Capabilities::default();
+        let writer_flags = naga::back::wgsl::WriterFlags::empty();
+
+        let module = naga::front::spv::parse_u8_slice(bytemuck::cast_slice(spv_binary), &opts)
+            .map_err(|err| {
+                sess.dcx()
+                    .err(format!("Naga failed to parse spv: \n{}", ShaderError {
+                        source: String::new(),
+                        label: None,
+                        inner: Box::new(err),
+                    }))
+            })?;
+        let mut validator =
+            naga::valid::Validator::new(naga::valid::ValidationFlags::default(), capabilities);
+        let info = validator.validate(&module).map_err(|err| {
+            sess.dcx()
+                .err(format!("Naga validation failed: \n{}", ShaderError {
+                    source: String::new(),
+                    label: None,
+                    inner: Box::new(err),
+                }))
+        })?;
+
+        let wgsl_dst = out_filename.with_extension("wgsl");
+        let wgsl = naga::back::wgsl::write_string(&module, &info, writer_flags).map_err(|err| {
+            sess.dcx()
+                .err(format!("Naga failed to write wgsl : \n{}", err))
+        })?;
+
+        std::fs::write(&wgsl_dst, wgsl).map_err(|err| {
+            sess.dcx()
+                .err(format!("failed to write wgsl to file: {}", err))
+        })?;
+
+        Ok(())
+    }
+}

crates/rustc_codegen_spirv/src/target.rs

@@ -33,6 +33,8 @@ impl TargetsExt for SpirvTargetEnv {
             | SpirvTargetEnv::Vulkan_1_2
             | SpirvTargetEnv::Vulkan_1_3
             | SpirvTargetEnv::Vulkan_1_4 => MemoryModel::Vulkan,
+
+            SpirvTargetEnv::Wgsl => MemoryModel::Vulkan,
         }
     }
 
@@ -57,6 +59,8 @@ impl TargetsExt for SpirvTargetEnv {
             SpirvTargetEnv::Vulkan_1_2 => spirv_tools::TargetEnv::Vulkan_1_2,
             SpirvTargetEnv::Vulkan_1_3 => spirv_tools::TargetEnv::Vulkan_1_3,
             SpirvTargetEnv::Vulkan_1_4 => spirv_tools::TargetEnv::Vulkan_1_4,
+
+            SpirvTargetEnv::Wgsl => spirv_tools::TargetEnv::Vulkan_1_2,
         }
     }
 

tests/compiletests/Cargo.toml

@@ -15,7 +15,7 @@ use-compiled-tools = ["rustc_codegen_spirv/use-compiled-tools"]
 
 [dependencies]
 compiletest = { version = "0.11.2", package = "compiletest_rs" }
-rustc_codegen_spirv = { workspace = true }
+rustc_codegen_spirv = { workspace = true, features = ["naga"] }
 rustc_codegen_spirv-target-specs = { workspace = true, features = ["dir_path"] }
 clap = { version = "4", features = ["derive"] }
 itertools = "0.10.5"

tests/compiletests/ui/arch/all_memory_barrier.rs

@@ -1,6 +1,7 @@
 // build-pass
 // compile-flags: -C target-feature=+VulkanMemoryModelDeviceScopeKHR,+ext:SPV_KHR_vulkan_memory_model
 // compile-flags: -C llvm-args=--disassemble-fn=all_memory_barrier::all_memory_barrier
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/convert_u_to_acceleration_structure_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayTracingKHR,+ext:SPV_KHR_ray_tracing
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/debug_printf.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+ext:SPV_KHR_non_semantic_info
+// ignore-wgsl
 
 use spirv_std::spirv;
 use spirv_std::{

tests/compiletests/ui/arch/demote_to_helper_invocation.rs

@@ -1,6 +1,7 @@
 // build-pass
 //
 // compile-flags: -C target-feature=+DemoteToHelperInvocationEXT,+ext:SPV_EXT_demote_to_helper_invocation
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/emit_stream_vertex.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -C target-feature=+GeometryStreams
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/emit_vertex.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+Geometry
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/end_primitive.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+Geometry
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/end_stream_primitive.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -C target-feature=+GeometryStreams
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/execute_callable.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayTracingKHR,+ext:SPV_KHR_ray_tracing
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/ignore_intersection_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayTracingKHR,+ext:SPV_KHR_ray_tracing
+// ignore-wgsl
 
 use spirv_std::spirv;
 

tests/compiletests/ui/arch/memory_barrier.rs

@@ -1,4 +1,5 @@
 // build-pass
+// ignore-wgsl
 
 #![feature(adt_const_params)]
 #![allow(incomplete_features)]

tests/compiletests/ui/arch/ray_query_confirm_intersection_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_barycentrics_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_candidate_aabb_opaque_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_front_face_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_geometry_index_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_instance_custom_index_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_instance_id_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_object_ray_direction_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_object_ray_origin_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};

tests/compiletests/ui/arch/ray_query_get_intersection_object_to_world_khr.rs

@@ -1,5 +1,6 @@
 // build-pass
 // compile-flags: -Ctarget-feature=+RayQueryKHR,+ext:SPV_KHR_ray_query
+// ignore-wgsl
 
 use glam::Vec3;
 use spirv_std::ray_tracing::{AccelerationStructure, RayFlags, RayQuery};