From 66bae403827a37bdc587f3356cc58fde166d04a1 Mon Sep 17 00:00:00 2001
From: Tim Foley <tfoley@nvidia.com>
Date: Fri, 14 Jul 2017 14:38:13 -0700
Subject: Add reflection support for GLSL thread-group-size modifier

Fixes #15

These are the modifiers like:

    layout(local_size_x = 16) in;

Unlike the HLSL case, these don't get attache to the entry point function itself, so there is a bit more work involed in looking them up.

Just to make sure I didn't mess up the HLSL case, I went ahead and added two tests for this capability: one for GLSL and one for HLSL.
---
 source/slang/reflection.cpp | 55 ++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 50 insertions(+), 5 deletions(-)

(limited to 'source/slang/reflection.cpp')

diff --git a/source/slang/reflection.cpp b/source/slang/reflection.cpp
index 3c89194c8..aaeae5595 100644
--- a/source/slang/reflection.cpp
+++ b/source/slang/reflection.cpp
@@ -204,7 +204,7 @@ SLANG_API size_t spReflectionType_GetElementCount(SlangReflectionType* inType)
 
     if(auto arrayType = dynamic_cast<ArrayExpressionType*>(type))
     {
-        return (size_t) GetIntVal(arrayType->ArrayLength);
+        return arrayType->ArrayLength ? (size_t) GetIntVal(arrayType->ArrayLength) : 0;
     }
     else if( auto vectorType = dynamic_cast<VectorExpressionType*>(type))
     {
@@ -751,12 +751,43 @@ SLANG_API void spReflectionEntryPoint_getComputeThreadGroupSize(
     auto entryPointFunc = entryPointLayout->entryPoint;
     if(!entryPointFunc) return;
 
+    SlangUInt sizeAlongAxis[3] = { 1, 1, 1 };
+
+    // First look for the HLSL case, where we have an attribute attached to the entry point function
     auto numThreadsAttribute = entryPointFunc->FindModifier<HLSLNumThreadsAttribute>();
-    if(!numThreadsAttribute) return;
+    if (numThreadsAttribute)
+    {
+        sizeAlongAxis[0] = numThreadsAttribute->x;
+        sizeAlongAxis[1] = numThreadsAttribute->y;
+        sizeAlongAxis[2] = numThreadsAttribute->z;
+    }
+    else
+    {
+        // Fall back to the GLSL case, which requires a search over global-scope declarations
+        // to look for anything with the `local_size_*` qualifier
+        auto module = dynamic_cast<ProgramSyntaxNode*>(entryPointFunc->ParentDecl);
+        if (module)
+        {
+            for (auto dd : module->Members)
+            {
+                for (auto mod : dd->GetModifiersOfType<GLSLLocalSizeLayoutModifier>())
+                {
+                    if (auto xMod = dynamic_cast<GLSLLocalSizeXLayoutModifier*>(mod))
+                        sizeAlongAxis[0] = (SlangUInt) getIntegerLiteralValue(xMod->valToken);
+                    else if (auto yMod = dynamic_cast<GLSLLocalSizeYLayoutModifier*>(mod))
+                        sizeAlongAxis[1] = (SlangUInt) getIntegerLiteralValue(yMod->valToken);
+                    else if (auto zMod = dynamic_cast<GLSLLocalSizeZLayoutModifier*>(mod))
+                        sizeAlongAxis[2] = (SlangUInt) getIntegerLiteralValue(zMod->valToken);
+                }
+            }
+        }
+    }
+
+    //
 
-    if(axisCount > 0) outSizeAlongAxis[0] = numThreadsAttribute->x;
-    if(axisCount > 1) outSizeAlongAxis[1] = numThreadsAttribute->y;
-    if(axisCount > 2) outSizeAlongAxis[2] = numThreadsAttribute->z;
+    if(axisCount > 0) outSizeAlongAxis[0] = sizeAlongAxis[0];
+    if(axisCount > 1) outSizeAlongAxis[1] = sizeAlongAxis[1];
+    if(axisCount > 2) outSizeAlongAxis[2] = sizeAlongAxis[2];
     for( SlangUInt aa = 3; aa < axisCount; ++aa )
     {
         outSizeAlongAxis[aa] = 1;
@@ -1526,6 +1557,20 @@ static void emitReflectionEntryPointJSON(
         write(writer, ",\n\"usesAnySampleRateInput\": true");
     }
 
+    if (entryPoint->getStage() == SLANG_STAGE_COMPUTE)
+    {
+        SlangUInt threadGroupSize[3];
+        entryPoint->getComputeThreadGroupSize(3, threadGroupSize);
+
+        write(writer, ",\n\"threadGroupSize\": [");
+        for (int ii = 0; ii < 3; ++ii)
+        {
+            if (ii != 0) write(writer, ", ");
+            write(writer, threadGroupSize[ii]);
+        }
+        write(writer, "]");
+    }
+
     dedent(writer);
     write(writer, "\n}");
 }
-- 
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