Add GLSL output to naga snapshots

naga/Cargo.toml

@@ -108,6 +108,7 @@ unicode-ident = { workspace = true, optional = true }
 cfg_aliases.workspace = true
 
 [dev-dependencies]
+bytemuck.workspace = true
 diff.workspace = true
 env_logger.workspace = true
 hashbrown = { workspace = true, features = ["serde"] }

naga/tests/naga/snapshots.rs

@@ -198,6 +198,109 @@ Note: this is an issue with snapshot configuration, not code. If you added a new
     }
 }
 
+fn spirv_cross_stage_name(stage: naga::ShaderStage) -> &'static str {
+    match stage {
+        naga::ShaderStage::Vertex => "vert",
+        naga::ShaderStage::Fragment => "frag",
+        naga::ShaderStage::Compute => "comp",
+        naga::ShaderStage::Task => "task",
+        naga::ShaderStage::Mesh => "mesh",
+        naga::ShaderStage::RayGeneration => "rgen",
+        naga::ShaderStage::Miss => "rmiss",
+        naga::ShaderStage::AnyHit => "rahit",
+        naga::ShaderStage::ClosestHit => "rchit",
+    }
+}
+
+fn run_spirv_cross(
+    spv_binary: &[u32],
+    entry_point: &str,
+    stage: naga::ShaderStage,
+) -> Result<String, String> {
+    use std::io::Write;
+    use std::process::{Command, Stdio};
+
+    let stage_name = spirv_cross_stage_name(stage);
+    let bytes: &[u8] = bytemuck::cast_slice(spv_binary);
+
+    let mut child = Command::new("spirv-cross")
+        .args([
+            "-V",
+            "--version", "460",
+            "--entry", entry_point,
+            "--stage", stage_name,
+            "-",
+        ])
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()
+        .expect(
+            "Failed to execute spirv-cross. Install it via the Vulkan SDK \
+             or from https://github.com/KhronosGroup/SPIRV-Cross",
+        );
+
+    child.stdin.take().unwrap().write_all(bytes).unwrap();
+
+    let output = child.wait_with_output().unwrap();
+    let stderr = String::from_utf8_lossy(&output.stderr).replace("\r\n", "\n");
+    let stdout = String::from_utf8_lossy(&output.stdout).replace("\r\n", "\n");
+
+    if !output.status.success() {
+        let mut commented = String::new();
+        for line in stderr.lines() {
+            commented.push_str(&format!("// {line}\n"));
+        }
+        Err(commented)
+    } else {
+        Ok(stdout)
+    }
+}
+
+/// Writes GLSL output generated by SPIRV-Cross for the given SPIR-V binary.
+///
+/// Behavior:
+/// - For multiple entry points, each GLSL output is prefixed with a comment block
+///   indicating the entry point name and shader stage (e.g., `// Entry point: "main" (frag) //`).
+/// - For a single entry point, no header is added (cleaner output for single-shader files).
+/// - On SPIRV-Cross failure, stderr is captured as commented lines in the output file,
+///   and the function continues to write remaining entry points. This ensures test
+///   snapshots are always generated even when translation fails.
+fn write_spirv_cross_glsl(
+    input: &Input,
+    spv_binary: &[u32],
+    entry_points: &[(String, naga::ShaderStage)],
+    extension: &str,
+) {
+    let multiple = entry_points.len() > 1;
+    let mut output = String::new();
+
+    for (i, (name, stage)) in entry_points.iter().enumerate() {
+        if multiple {
+            if i > 0 {
+                output.push('\n');
+            }
+            let stage_name = spirv_cross_stage_name(*stage);
+            let inner = format!(" Entry point: \"{name}\" ({stage_name}) ");
+            let width = inner.len() + 4; // "// " + inner + " //"
+            let bar: String = "/".repeat(width);
+            output.push_str(&bar);
+            output.push('\n');
+            output.push_str(&format!("//{inner}//"));
+            output.push('\n');
+            output.push_str(&bar);
+            output.push('\n');
+        }
+
+        match run_spirv_cross(spv_binary, name, *stage) {
+            Ok(glsl) => output.push_str(&glsl),
+            Err(err) => output.push_str(&err),
+        }
+    }
+
+    input.write_output_file("spv", extension, output, DIR_OUT);
+}
+
 fn write_output_spv(
     input: &Input,
     module: &naga::Module,
@@ -221,17 +324,29 @@ fn write_output_spv(
                 entry_point: ep.name.clone(),
                 shader_stage: ep.stage,
             };
-            write_output_spv_inner(
+            let spv_binary = write_output_spv_inner(
                 input,
                 &module,
                 &info,
                 &options,
                 Some(&pipeline_options),
                 &format!("{}.spvasm", ep.name),
             );
+            write_spirv_cross_glsl(
+                input,
+                &spv_binary,
+                &[(ep.name.clone(), ep.stage)],
+                &format!("{}.spvasm.glsl", ep.name),
+            );
         }
     } else {
-        write_output_spv_inner(input, &module, &info, &options, None, "spvasm");
+        let spv_binary = write_output_spv_inner(input, &module, &info, &options, None, "spvasm");
+        let entry_points: Vec<(String, naga::ShaderStage)> = module
+            .entry_points
+            .iter()
+            .map(|ep| (ep.name.clone(), ep.stage))
+            .collect();
+        write_spirv_cross_glsl(input, &spv_binary, &entry_points, "spvasm.glsl");
     }
 }
 
@@ -242,12 +357,12 @@ fn write_output_spv_inner(
     options: &naga::back::spv::Options<'_>,
     pipeline_options: Option<&naga::back::spv::PipelineOptions>,
     extension: &str,
-) {
+) -> Vec<u32> {
     use naga::back::spv;
     use rspirv::binary::Disassemble;
     println!("Generating SPIR-V for {:?}", input.file_name);
     let spv = spv::write_vec(module, info, options, pipeline_options).unwrap();
-    let dis = rspirv::dr::load_words(spv)
+    let dis = rspirv::dr::load_words(spv.clone())
         .expect("Produced invalid SPIR-V")
         .disassemble();
     // HACK escape CR/LF if source code is in side.
@@ -258,6 +373,7 @@ fn write_output_spv_inner(
         dis
     };
     input.write_output_file("spv", extension, dis, DIR_OUT);
+    spv
 }
 
 fn write_output_msl(

naga/tests/out/spv/spv-barrier.spvasm.glsl

@@ -0,0 +1,18 @@
+#version 450
+layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
+
+void _4()
+{
+    barrier();
+    memoryBarrierBuffer();
+    memoryBarrierImage();
+    barrier();
+    memoryBarrier();
+    barrier();
+}
+
+void main()
+{
+    _4();
+}
+

naga/tests/out/spv/spv-fetch_depth.spvasm.glsl

@@ -0,0 +1,35 @@
+#version 450
+layout(local_size_x = 32, local_size_y = 1, local_size_z = 1) in;
+
+struct _5
+{
+    float _m0;
+};
+
+struct _8
+{
+    uvec2 _m0;
+};
+
+layout(binding = 0, std430) buffer _12_11
+{
+    _5 _m0;
+} _11;
+
+layout(binding = 1, std430) readonly buffer _15_14
+{
+    _8 _m0;
+} _14;
+
+uniform sampler2D SPIRV_Cross_CombinedSPIRV_Cross_DummySampler;
+
+void _20()
+{
+    _11._m0._m0 = vec4(texelFetch(SPIRV_Cross_CombinedSPIRV_Cross_DummySampler, ivec2(_14._m0._m0), 0).x).x;
+}
+
+void main()
+{
+    _20();
+}
+

naga/tests/out/spv/spv-per-vertex.spvasm.glsl

@@ -0,0 +1,20 @@
+#version 450
+#extension GL_EXT_fragment_shader_barycentric : require
+
+layout(location = 0) pervertexEXT in float _25[3];
+layout(location = 0) out vec4 _28;
+float _9[3] = float[](0.0, 0.0, 0.0);
+vec4 _12 = vec4(0.0);
+
+void _16()
+{
+    _12 = vec4(_9[0], _9[1], _9[2], 1.0);
+}
+
+void main()
+{
+    _9 = _25;
+    _16();
+    _28 = _12;
+}
+

naga/tests/out/spv/spv-subgroup-barrier.spvasm.glsl

@@ -0,0 +1,44 @@
+#version 450
+
+#if defined(GL_KHR_shader_subgroup_basic)
+#extension GL_KHR_shader_subgroup_basic : require
+#elif defined(GL_NV_shader_thread_group)
+#extension GL_NV_shader_thread_group : require
+#elif defined(GL_ARB_shader_ballot) && defined(GL_ARB_shader_int64)
+#extension GL_ARB_shader_int64 : enable
+#extension GL_ARB_shader_ballot : require
+#elif defined(GL_AMD_gcn_shader) && (defined(GL_AMD_gpu_shader_int64) || defined(GL_NV_gpu_shader5))
+#extension GL_AMD_gpu_shader_int64 : enable
+#extension GL_NV_gpu_shader5 : enable
+#extension GL_AMD_gcn_shader : require
+#else
+#error No extensions available to emulate requested subgroup feature.
+#endif
+
+#if defined(GL_KHR_shader_subgroup_basic)
+#extension GL_KHR_shader_subgroup_basic : require
+#endif
+layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
+
+#ifndef GL_KHR_shader_subgroup_basic
+void subgroupBarrier() { memoryBarrierShared(); }
+#endif
+
+#ifndef GL_KHR_shader_subgroup_basic
+void subgroupMemoryBarrier() { groupMemoryBarrier(); }
+void subgroupMemoryBarrierBuffer() { groupMemoryBarrier(); }
+void subgroupMemoryBarrierShared() { memoryBarrierShared(); }
+void subgroupMemoryBarrierImage() { groupMemoryBarrier(); }
+#endif
+
+void _4()
+{
+    subgroupMemoryBarrier();
+    subgroupBarrier();
+}
+
+void main()
+{
+    _4();
+}
+

naga/tests/out/spv/wgsl-6220-break-from-loop.spvasm.glsl

@@ -0,0 +1,27 @@
+#version 460
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+
+void _5()
+{
+    int _10 = 0;
+    uvec2 _27 = uvec2(4294967295u);
+    for (;;)
+    {
+        if (all(equal(uvec2(0u), _27)))
+        {
+            break;
+        }
+        _27 -= uvec2(uint(_27.y == 0u), 1u);
+        if (!(_10 < 4))
+        {
+            break;
+        }
+        break;
+    }
+}
+
+void main()
+{
+    _5();
+}
+

naga/tests/out/spv/wgsl-6438-conflicting-idents.spvasm.glsl

@@ -0,0 +1,41 @@
+//////////////////////////////
+// Entry point: "vs" (vert) //
+//////////////////////////////
+#version 460
+
+struct _6
+{
+    vec4 _m0;
+    vec2 _m1;
+};
+
+layout(location = 0) in vec2 _8;
+layout(location = 0) out vec2 _13;
+
+void main()
+{
+    _6 _19 = _6(vec4(0.0), vec2(0.0));
+    _19._m0 = vec4(_8, 0.0, 1.0);
+    gl_Position = _19._m0;
+    _13 = _19._m1;
+}
+
+
+//////////////////////////////
+// Entry point: "fs" (frag) //
+//////////////////////////////
+#version 460
+
+struct _6
+{
+    vec4 _m0;
+    vec2 _m1;
+};
+
+layout(location = 0) out vec4 _32;
+
+void main()
+{
+    _32 = vec4(1.0, 0.0, 0.0, 1.0);
+}
+

naga/tests/out/spv/wgsl-6772-unpack-expr-accesses.spvasm.glsl

@@ -0,0 +1,9 @@
+#version 460
+#extension GL_EXT_shader_explicit_arithmetic_types_int8 : require
+#extension GL_EXT_shader_8bit_storage : require
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+
+void main()
+{
+}
+

naga/tests/out/spv/wgsl-7048-multiple-dynamic-1.spvasm.glsl

@@ -0,0 +1,13 @@
+#version 460
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+
+const vec3 _13[2] = vec3[](vec3(0.0), vec3(0.0));
+
+void main()
+{
+    vec4 _17 = vec4(0.0);
+    int _19 = 0;
+    int _21 = 0;
+    _17.x += (_13[_21].y * _13[_19].z);
+}
+