Add COM API for querying metadata. (#5168)

* Add COM API for querying metadata.

* Fix tests.

* fix test.

3 files changed, 29 insertions, 1 deletions

diff --git a/source/compiler-core/slang-artifact-associated-impl.cpp b/source/compiler-core/slang-artifact-associated-impl.cpp
index f29c0f596..07d69bf8e 100644
--- a/source/compiler-core/slang-artifact-associated-impl.cpp
+++ b/source/compiler-core/slang-artifact-associated-impl.cpp
@@ -313,4 +313,24 @@ Slice<String> ArtifactPostEmitMetadata::getExportedFunctionMangledNames()
     return Slice<String>(m_exportedFunctionMangledNames.getBuffer(), m_exportedFunctionMangledNames.getCount());
 }
 
+SlangResult ArtifactPostEmitMetadata::isParameterLocationUsed(
+    SlangParameterCategory category,
+    SlangUInt spaceIndex,
+    SlangUInt registerIndex,
+    bool& outUsed)
+{
+    for (const auto& range : getUsedBindingRanges())
+    {
+        if (range.containsBinding((slang::ParameterCategory)category, spaceIndex, registerIndex))
+        {
+            outUsed = true;
+            return SLANG_OK;
+        }
+    }
+
+    outUsed = false;
+    return SLANG_OK;
+}
+
+
 } // namespace Slang
diff --git a/source/compiler-core/slang-artifact-associated-impl.h b/source/compiler-core/slang-artifact-associated-impl.h
index a6e323b0a..d11498604 100644
--- a/source/compiler-core/slang-artifact-associated-impl.h
+++ b/source/compiler-core/slang-artifact-associated-impl.h
@@ -134,6 +134,7 @@ struct ShaderBindingRange
         case slang::ShaderResource:
         case slang::UnorderedAccess:
         case slang::SamplerState:
+        case slang::DescriptorTableSlot:
             return true;
         default:
             return false;
@@ -157,6 +158,13 @@ public:
     SLANG_NO_THROW virtual Slice<ShaderBindingRange> SLANG_MCALL getUsedBindingRanges() SLANG_OVERRIDE;
     SLANG_NO_THROW virtual Slice<String> SLANG_MCALL getExportedFunctionMangledNames() SLANG_OVERRIDE;
 
+    // IMetadata
+    SLANG_NO_THROW virtual SlangResult SLANG_MCALL isParameterLocationUsed(
+        SlangParameterCategory category, // is this a `t` register? `s` register?
+        SlangUInt spaceIndex,      // `space` for D3D12, `set` for Vulkan
+        SlangUInt registerIndex,   // `register` for D3D12, `binding` for Vulkan
+        bool& outUsed) SLANG_OVERRIDE;
+
     void* getInterface(const Guid& uuid);
     void* getObject(const Guid& uuid);
 
diff --git a/source/compiler-core/slang-artifact-associated.h b/source/compiler-core/slang-artifact-associated.h
index 766494271..91ae09aab 100644
--- a/source/compiler-core/slang-artifact-associated.h
+++ b/source/compiler-core/slang-artifact-associated.h
@@ -117,7 +117,7 @@ public:
 
 struct ShaderBindingRange;
 
-class IArtifactPostEmitMetadata : public ICastable
+class IArtifactPostEmitMetadata : public slang::IMetadata
 {
 public:
     SLANG_COM_INTERFACE(0x5d03bce9, 0xafb1, 0x4fc8, { 0xa4, 0x6f, 0x3c, 0xe0, 0x7b, 0x6, 0x1b, 0x1b });