Add COM API for querying metadata. (#5168)

* Add COM API for querying metadata.

* Fix tests.

* fix test.

1 files changed, 68 insertions, 0 deletions

diff --git a/tools/slang-unit-test/unit-test-parameter-usage-reflection.cpp b/tools/slang-unit-test/unit-test-parameter-usage-reflection.cpp
new file mode 100644
index 000000000..911bdc5a4
--- /dev/null
+++ b/tools/slang-unit-test/unit-test-parameter-usage-reflection.cpp
@@ -0,0 +1,68 @@
+// unit-test-parameter-usage-reflection.cpp
+
+#include "slang.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "tools/unit-test/slang-unit-test.h"
+#include "slang-com-ptr.h"
+#include "../../source/core/slang-io.h"
+#include "../../source/core/slang-process.h"
+
+using namespace Slang;
+
+// Test that the isParameterLocationUsed API works.
+
+SLANG_UNIT_TEST(isParameterLocationUsedReflection)
+{
+    // Source for a module that contains an undecorated entrypoint.
+    const char* userSourceBody = R"(
+        Texture2D g_tex : register(t0);
+        [shader("fragment")]
+        float4 fragMain(float4 pos:SV_Position) : SV_Target
+        {
+            return g_tex.Load(int3(0, 0, 0));
+        }
+        )";
+
+    auto moduleName = "moduleG" + String(Process::getId());
+    String userSource = "import " + moduleName + ";\n" + userSourceBody;
+    ComPtr<slang::IGlobalSession> globalSession;
+    SLANG_CHECK(slang_createGlobalSession(SLANG_API_VERSION, globalSession.writeRef()) == SLANG_OK);
+    slang::TargetDesc targetDesc = {};
+    targetDesc.format = SLANG_SPIRV;
+    targetDesc.profile = globalSession->findProfile("spirv_1_5");
+    slang::SessionDesc sessionDesc = {};
+    sessionDesc.targetCount = 1;
+    sessionDesc.targets = &targetDesc;
+    ComPtr<slang::ISession> session;
+    SLANG_CHECK(globalSession->createSession(sessionDesc, session.writeRef()) == SLANG_OK);
+
+    ComPtr<slang::IBlob> diagnosticBlob;
+    auto module = session->loadModuleFromSourceString("m", "m.slang", userSourceBody, diagnosticBlob.writeRef());
+    SLANG_CHECK(module != nullptr);
+
+    ComPtr<slang::IEntryPoint> entryPoint;
+    module->findAndCheckEntryPoint("fragMain", SLANG_STAGE_FRAGMENT, entryPoint.writeRef(), diagnosticBlob.writeRef());
+    SLANG_CHECK(entryPoint != nullptr);
+
+    ComPtr<slang::IComponentType> compositeProgram;
+    slang::IComponentType* components[] = { module, entryPoint.get() };
+    session->createCompositeComponentType(components, 2, compositeProgram.writeRef(), diagnosticBlob.writeRef());
+    SLANG_CHECK(compositeProgram != nullptr);
+
+    ComPtr<slang::IComponentType> linkedProgram;
+    compositeProgram->link(linkedProgram.writeRef(), nullptr);
+
+    ComPtr<slang::IMetadata> metadata;
+    linkedProgram->getTargetMetadata(0, metadata.writeRef(), nullptr);
+
+    bool isUsed = false;
+    metadata->isParameterLocationUsed(SLANG_PARAMETER_CATEGORY_DESCRIPTOR_TABLE_SLOT, 0, 0, isUsed);
+    SLANG_CHECK(isUsed);
+
+    metadata->isParameterLocationUsed(SLANG_PARAMETER_CATEGORY_DESCRIPTOR_TABLE_SLOT, 0, 1, isUsed);
+    SLANG_CHECK(!isUsed);
+}
+