Feature/early depth stencil (#727)

* First pass support for early depth stencil.

* Add a simple test to check if output has attributes.

* Use cross compilation to test [earlydepthstencil] on glsl.

* If target is dxil, use dxc to test against.
Add hlsl to test earlydepthstencil against.

* * Added spSessionHasCompileTargetSupport
* Made slang-test use spSessionHasCompileTargetSupport to ignore tests that cannot run

23 files changed, 285 insertions, 19 deletions

diff --git a/premake5.lua b/premake5.lua
index 8e02d433f..dcc86913a 100644
--- a/premake5.lua
+++ b/premake5.lua
@@ -435,7 +435,7 @@ tool "slang-generate"
 tool "slang-test"
     uuid "0C768A18-1D25-4000-9F37-DA5FE99E3B64"
     includedirs { "." }
-    links { "core" }
+    links { "core", "slang" }
 
 --
 -- The reflection test harness `slang-reflection-test` is pretty
diff --git a/slang.h b/slang.h
index f7ef2f9ee..1775e0de4 100644
--- a/slang.h
+++ b/slang.h
@@ -1,4 +1,4 @@
-#ifndef SLANG_H
+#ifndef SLANG_H
 #define SLANG_H
 
 /** \file slang.h
@@ -354,7 +354,7 @@ extern "C"
     typedef uint32_t    SlangUInt32;
     typedef intptr_t    SlangInt;
     typedef uintptr_t   SlangUInt;
-
+    
     /*!
     @brief Severity of a diagnostic generated by the compiler.
     Values come from the enum below, with higher values representing more severe
@@ -846,6 +846,15 @@ extern "C"
         SlangSession*   session);
 
     /*!
+    @brief Returns SLANG_OK if a the compilation target is supported for this session
+    @param session Session
+    @param target The compilation target to test
+    @return SLANG_OK if the target is available */
+    SLANG_API SlangResult spSessionHasCompileTargetSupport(
+        SlangSession*       session,
+        SlangCompileTarget  target);
+
+    /*!
     @brief Add new builtin declarations to be used in subsequent compiles.
     */
     SLANG_API void spAddBuiltins(
diff --git a/source/core/platform.cpp b/source/core/platform.cpp
index b96240def..d160fd37c 100644
--- a/source/core/platform.cpp
+++ b/source/core/platform.cpp
@@ -85,10 +85,13 @@ namespace Slang
 	void* h = dlopen(platformFileName, RTLD_NOW | RTLD_LOCAL);
 	if(!h)
 	{
+#if 0
+        // We can't output the error message here, because it will cause output when testing what code gen is available
 		if(auto msg = dlerror())
 		{
 			fprintf(stderr, "error: %s\n", msg);
 		}
+#endif
         return SLANG_FAIL;
 	}
     handleOut = (Handle)h;
@@ -116,4 +119,4 @@ namespace Slang
 
 #endif // _WIN32
 
-}
\ No newline at end of file
+}
diff --git a/source/slang-glslang/slang-glslang.vcxproj b/source/slang-glslang/slang-glslang.vcxproj
index 28e64e8de..eb53fc311 100644
--- a/source/slang-glslang/slang-glslang.vcxproj
+++ b/source/slang-glslang/slang-glslang.vcxproj
@@ -200,6 +200,7 @@
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\iomapper.h" />
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\localintermediate.h" />
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\parseVersions.h" />
+    <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\pch.h" />
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\preprocessor\PpContext.h" />
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\preprocessor\PpTokens.h" />
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\propagateNoContraction.h" />
@@ -242,6 +243,7 @@
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\limits.cpp" />
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\linkValidate.cpp" />
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\parseConst.cpp" />
+    <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\pch.cpp" />
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\preprocessor\Pp.cpp" />
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\preprocessor\PpAtom.cpp" />
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\preprocessor\PpContext.cpp" />
diff --git a/source/slang-glslang/slang-glslang.vcxproj.filters b/source/slang-glslang/slang-glslang.vcxproj.filters
index 2e15ff5bd..482728c71 100644
--- a/source/slang-glslang/slang-glslang.vcxproj.filters
+++ b/source/slang-glslang/slang-glslang.vcxproj.filters
@@ -111,6 +111,9 @@
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\parseVersions.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\pch.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="..\..\external\glslang\glslang\MachineIndependent\preprocessor\PpContext.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -233,6 +236,9 @@
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\parseConst.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\pch.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\external\glslang\glslang\MachineIndependent\preprocessor\Pp.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/source/slang/check.cpp b/source/slang/check.cpp
index 00c6f6dd0..e07bdf156 100644
--- a/source/slang/check.cpp
+++ b/source/slang/check.cpp
@@ -311,7 +311,10 @@ namespace Slang
             const char* libName = DefaultSharedLibraryLoader::getSharedLibraryNameFromType(type);
             if (SLANG_FAILED(sharedLibraryLoader->loadSharedLibrary(libName, sharedLibraries[int(type)].writeRef())))
             {
-                sink->diagnose(SourceLoc(), Diagnostics::failedToLoadDynamicLibrary, libName);
+                if (sink)
+                {
+                    sink->diagnose(SourceLoc(), Diagnostics::failedToLoadDynamicLibrary, libName);
+                }
                 return nullptr;
             }
         }
@@ -2072,6 +2075,11 @@ namespace Slang
                     // Has no args
                     SLANG_ASSERT(attr->args.Count() == 0);
                 }
+                else if (attr.As<EarlyDepthStencilAttribute>())
+                {
+                    // Has no args
+                    SLANG_ASSERT(attr->args.Count() == 0);
+                }
                 else
                 {
                     if(attr->args.Count() == 0)
diff --git a/source/slang/compiler.cpp b/source/slang/compiler.cpp
index cab6355c1..1e514812a 100644
--- a/source/slang/compiler.cpp
+++ b/source/slang/compiler.cpp
@@ -181,6 +181,64 @@ namespace Slang
     }
 
 
+    bool hasCodeGenTarget(Session* session, CodeGenTarget target)
+    {
+        switch (target)
+        {
+            case CodeGenTarget::Unknown:     return false;
+            case CodeGenTarget::None:       return true;
+            case CodeGenTarget::GLSL:
+            case CodeGenTarget::GLSL_Vulkan:
+            case CodeGenTarget::GLSL_Vulkan_OneDesc:
+            {
+                // Can always output GLSL
+                return true;
+            }
+            case CodeGenTarget::HLSL:
+            {
+                // Can always output HLSL
+                return true;
+            }
+            case CodeGenTarget::SPIRVAssembly:
+            case CodeGenTarget::SPIRV:
+            {
+#if SLANG_ENABLE_GLSLANG_SUPPORT
+                return session->getOrLoadSharedLibrary(Slang::SharedLibraryType::Glslang, nullptr) != nullptr;
+#else
+                return false;
+#endif
+            }            
+            case CodeGenTarget::DXBytecode:
+            case CodeGenTarget::DXBytecodeAssembly:
+            {
+#if SLANG_ENABLE_DXBC_SUPPORT
+                // Must have fxc
+                return session->getOrLoadSharedLibrary(SharedLibraryType::Fxc, nullptr) != nullptr;
+#else
+                return false;
+#endif
+            }
+
+            case CodeGenTarget::DXIL:
+            case CodeGenTarget::DXILAssembly:
+            {
+#if SLANG_ENABLE_DXIL_SUPPORT
+                // Must have dxc
+                return session->getOrLoadSharedLibrary(SharedLibraryType::Dxc, nullptr) &&
+                    session->getOrLoadSharedLibrary(SharedLibraryType::Dxil, nullptr);
+#else
+                return false;
+#endif
+            }
+
+            default:
+            {
+                SLANG_ASSERT(!"Unhandled target");
+                return false;
+            }
+        }
+    }
+
     //
 
     String emitHLSLForEntryPoint(
diff --git a/source/slang/compiler.h b/source/slang/compiler.h
index c8c242568..0eaf6e8e9 100644
--- a/source/slang/compiler.h
+++ b/source/slang/compiler.h
@@ -1,4 +1,4 @@
-#ifndef SLANG_COMPILER_H_INCLUDED
+#ifndef SLANG_COMPILER_H_INCLUDED
 #define SLANG_COMPILER_H_INCLUDED
 
 #include "../core/basic.h"
@@ -499,6 +499,9 @@ namespace Slang
         char const*     text,
         CodeGenTarget   target);
 
+    /* Returns true if a codeGen target is available. */
+    bool hasCodeGenTarget(Session* session, CodeGenTarget target);
+
     struct TypeCheckingCache;
     //
 
diff --git a/source/slang/emit.cpp b/source/slang/emit.cpp
index a3b99691d..bf98a1b24 100644
--- a/source/slang/emit.cpp
+++ b/source/slang/emit.cpp
@@ -4702,6 +4702,14 @@ struct EmitVisitor
 
             break;
         }
+        case Stage::Pixel:
+        {
+            if (irFunc->findDecoration<IREarlyDepthStencilDecoration>())
+            {
+                emit("[earlydepthstencil]\n");
+            }
+            break;
+        }
         // TODO: There are other stages that will need this kind of handling.
         default:
             break;
@@ -4709,7 +4717,7 @@ struct EmitVisitor
     }
 
     void emitIREntryPointAttributes_GLSL(
-        IRFunc*             /*irFunc*/,
+        IRFunc*             irFunc,
         EmitContext*        /*ctx*/,
         EntryPointLayout*   entryPointLayout)
     {
@@ -4805,6 +4813,15 @@ struct EmitVisitor
 
         }
         break;
+        case Stage::Pixel:
+        {
+            if (irFunc->findDecoration<IREarlyDepthStencilDecoration>())
+            {
+                // https://www.khronos.org/opengl/wiki/Early_Fragment_Test
+                emit("layout(early_fragment_tests) in;\n");
+            }
+            break;
+        }
         // TODO: There are other stages that will need this kind of handling.
         default:
             break;
diff --git a/source/slang/ir-insts.h b/source/slang/ir-insts.h
index 5cbdf326e..fc0c5f884 100644
--- a/source/slang/ir-insts.h
+++ b/source/slang/ir-insts.h
@@ -160,6 +160,11 @@ struct IRReadNoneDecoration : IRDecoration
     enum { kDecorationOp = kIRDecorationOp_ReadNone };
 };
 
+struct IREarlyDepthStencilDecoration : IRDecoration
+{
+    enum { kDecorationOp = kIRDecorationOp_EarlyDepthStencil };
+};
+
 // An instruction that specializes another IR value
 // (representing a generic) to a particular set of generic arguments 
 // (instructions representing types, witness tables, etc.)
diff --git a/source/slang/ir-serialize.cpp b/source/slang/ir-serialize.cpp
index 7e7c6c8a7..d8a01fb56 100644
--- a/source/slang/ir-serialize.cpp
+++ b/source/slang/ir-serialize.cpp
@@ -706,6 +706,7 @@ Result IRSerialWriter::write(IRModule* module, SourceManager* sourceManager, Opt
                 case kIRDecorationOp_VulkanRayPayload:
                 case kIRDecorationOp_VulkanCallablePayload:
                 case kIRDecorationOp_VulkanHitAttributes:
+                case kIRDecorationOp_EarlyDepthStencil:
                 case kIRDecorationOp_ReadNone:
                 {
                     dstInst.m_payloadType = PayloadType::Empty;
@@ -1567,6 +1568,12 @@ IRDecoration* IRSerialReader::_createDecoration(const Ser::Inst& srcInst)
             SLANG_ASSERT(srcInst.m_payloadType == PayloadType::Empty);
             return decor;
         }
+        case kIRDecorationOp_EarlyDepthStencil:
+        {
+            auto decor = createEmptyDecoration<IREarlyDepthStencilDecoration>(m_module);
+            SLANG_ASSERT(srcInst.m_payloadType == PayloadType::Empty);
+            return decor;
+        }
         case kIRDecorationOp_VulkanHitAttributes:
         {
             auto decor = createEmptyDecoration<IRVulkanHitAttributesDecoration>(m_module);
diff --git a/source/slang/ir.cpp b/source/slang/ir.cpp
index 356648212..664927e8a 100644
--- a/source/slang/ir.cpp
+++ b/source/slang/ir.cpp
@@ -2949,6 +2949,11 @@ namespace Slang
                     dump(context, "\n[__readNone]");
                 }
                 break;
+            case kIRDecorationOp_EarlyDepthStencil:
+                {
+                    dump(context, "\n[earlydepthstencil]");
+                }
+                break;
             }
         }
     }
@@ -5387,7 +5392,11 @@ namespace Slang
                     context->builder->addDecoration<IRVulkanCallablePayloadDecoration>(clonedValue);
                 }
                 break;
-
+            case kIRDecorationOp_EarlyDepthStencil:
+                {
+                    context->builder->addDecoration<IREarlyDepthStencilDecoration>(clonedValue);
+                }
+                break;
             case kIRDecorationOp_VulkanHitAttributes:
                 {
                     context->builder->addDecoration<IRVulkanHitAttributesDecoration>(clonedValue);
diff --git a/source/slang/ir.h b/source/slang/ir.h
index b3c690c26..b8c8e85f2 100644
--- a/source/slang/ir.h
+++ b/source/slang/ir.h
@@ -160,6 +160,8 @@ enum IRDecorationOp : uint16_t
     kIRDecorationOp_ReadNone,
     kIRDecorationOp_VulkanCallablePayload,
 
+    kIRDecorationOp_EarlyDepthStencil,
+
     kIRDecorationOp_CountOf
 };
 
diff --git a/source/slang/lower-to-ir.cpp b/source/slang/lower-to-ir.cpp
index 4f40b4af6..1390cddaf 100644
--- a/source/slang/lower-to-ir.cpp
+++ b/source/slang/lower-to-ir.cpp
@@ -5146,6 +5146,11 @@ struct DeclLoweringVisitor : DeclVisitor<DeclLoweringVisitor, LoweredValInfo>
             getBuilder()->addDecoration<IRReadNoneDecoration>(irFunc);
         }
 
+        if (decl->FindModifier<EarlyDepthStencilAttribute>())
+        {
+            getBuilder()->addDecoration<IREarlyDepthStencilDecoration>(irFunc);
+        }
+
         // For convenience, ensure that any additional global
         // values that were emitted while outputting the function
         // body appear before the function itself in the list
diff --git a/source/slang/modifier-defs.h b/source/slang/modifier-defs.h
index f6f55ecbd..5c86301ad 100644
--- a/source/slang/modifier-defs.h
+++ b/source/slang/modifier-defs.h
@@ -327,6 +327,7 @@ SIMPLE_SYNTAX_CLASS(FlattenAttribute, Attribute)            // `[flatten]`
 SIMPLE_SYNTAX_CLASS(ForceCaseAttribute, Attribute)          // `[forcecase]`
 SIMPLE_SYNTAX_CLASS(CallAttribute, Attribute)               // `[call]`
 
+
 // [[vk_push_constant]] [[push_constant]]
 SIMPLE_SYNTAX_CLASS(PushConstantAttribute, Attribute)
 
@@ -348,7 +349,7 @@ SYNTAX_CLASS(PatchConstantFuncAttribute, Attribute)
 END_SYNTAX_CLASS()
 SIMPLE_SYNTAX_CLASS(DomainAttribute, Attribute)
 
-SIMPLE_SYNTAX_CLASS(EarlyDepthStencilAttribute, Attribute)
+SIMPLE_SYNTAX_CLASS(EarlyDepthStencilAttribute, Attribute)  // `[earlydepthstencil]`
 
 // An HLSL `[numthreads(x,y,z)]` attribute
 SYNTAX_CLASS(NumThreadsAttribute, Attribute)
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index 28b504831..ef71430fc 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -1,4 +1,4 @@
-#include "../../slang.h"
+#include "../../slang.h"
 
 #include "../core/slang-io.h"
 #include "../core/slang-string-util.h"
@@ -1147,6 +1147,14 @@ SLANG_API ISlangSharedLibraryLoader* spSessionGetSharedLibraryLoader(
     return (s->sharedLibraryLoader == Slang::DefaultSharedLibraryLoader::getSingleton()) ? nullptr : s->sharedLibraryLoader.get();
 }
 
+SLANG_API SlangResult spSessionHasCompileTargetSupport(
+    SlangSession*                session,
+    SlangCompileTarget           target)
+{
+    auto s = SESSION(session);
+    return Slang::hasCodeGenTarget(s, Slang::CodeGenTarget(target)) ? SLANG_OK : SLANG_FAIL;
+}
+
 SLANG_API SlangCompileRequest* spCreateCompileRequest(
     SlangSession* session)
 {
diff --git a/tests/cross-compile/early-depth-stencil.hlsl b/tests/cross-compile/early-depth-stencil.hlsl
new file mode 100644
index 000000000..b40a29aba
--- /dev/null
+++ b/tests/cross-compile/early-depth-stencil.hlsl
@@ -0,0 +1,9 @@
+//TEST:CROSS_COMPILE:-target spirv-assembly -entry main -stage fragment
+//TEST:CROSS_COMPILE:-profile ps_6_0 -target dxil-assembly -entry main 
+
+[earlydepthstencil]
+float4 main(): SV_Target
+{
+    return float4(1, 0, 0, 1); 
+}
+
diff --git a/tests/cross-compile/early-depth-stencil.hlsl.glsl b/tests/cross-compile/early-depth-stencil.hlsl.glsl
new file mode 100644
index 000000000..73e258a82
--- /dev/null
+++ b/tests/cross-compile/early-depth-stencil.hlsl.glsl
@@ -0,0 +1,16 @@
+//TEST_IGNORE_FILE:
+#version 450
+layout(row_major) uniform;
+layout(row_major) buffer;
+
+#line 5 0
+layout(location = 0)
+out vec4 _S1;
+
+#line 5
+layout(early_fragment_tests) in;
+void main()
+{
+    _S1 = vec4(float(1), float(0), float(0), float(1));
+    return;
+}
diff --git a/tests/cross-compile/early-depth-stencil.hlsl.hlsl b/tests/cross-compile/early-depth-stencil.hlsl.hlsl
new file mode 100644
index 000000000..378c5c0a1
--- /dev/null
+++ b/tests/cross-compile/early-depth-stencil.hlsl.hlsl
@@ -0,0 +1,8 @@
+//TEST_IGNORE_FILE:
+#pragma pack_matrix(column_major)
+
+[earlydepthstencil]
+vector<float,4> main() : SV_TARGET
+{
+    return vector<float,4>((float) 1, (float) 0, (float) 0, (float) 1);
+}
diff --git a/tools/slang-test/main.cpp b/tools/slang-test/main.cpp
index 30fa709d7..9ce92f5bb 100644
--- a/tools/slang-test/main.cpp
+++ b/tools/slang-test/main.cpp
@@ -1,4 +1,4 @@
-// main.cpp
+// main.cpp
 
 #include "../../source/core/slang-io.h"
 #include "../../source/core/token-reader.h"
@@ -900,6 +900,25 @@ TestResult runEvalTest(TestContext* context, TestInput& input)
     return result;
 }
 
+static SlangCompileTarget _getCompileTarget(const UnownedStringSlice& name)
+{
+#define CASE(NAME, TARGET)  if(name == NAME) return SLANG_##TARGET;
+
+    CASE("hlsl", HLSL)
+    CASE("glsl", GLSL)
+    CASE("dxbc", DXBC)
+    CASE("dxbc-assembly", DXBC_ASM)
+    CASE("dxbc-asm", DXBC_ASM)
+    CASE("spirv", SPIRV)
+    CASE("spirv-assembly", SPIRV_ASM)
+    CASE("spirv-asm", SPIRV_ASM)
+    CASE("dxil", DXIL)
+    CASE("dxil-assembly", DXIL_ASM)
+    CASE("dxil-asm", DXIL_ASM)
+#undef CASE
+
+    return SLANG_TARGET_UNKNOWN;
+}
 
 TestResult runCrossCompilerTest(TestContext* context, TestInput& input)
 {
@@ -916,10 +935,39 @@ TestResult runCrossCompilerTest(TestContext* context, TestInput& input)
     expectedSpawner.pushExecutablePath(String(g_options.binDir) + "slangc" + osGetExecutableSuffix());
 
     actualSpawner.pushArgument(filePath);
-    expectedSpawner.pushArgument(filePath + ".glsl");
-    expectedSpawner.pushArgument("-pass-through");
-    expectedSpawner.pushArgument("glslang");
 
+    const auto& args = input.testOptions->args;
+
+    const UInt targetIndex = args.IndexOf("-target");
+    if (targetIndex != UInt(-1) && targetIndex + 1 < args.Count())
+    {
+        SlangCompileTarget target = _getCompileTarget(args[targetIndex + 1].getUnownedSlice());
+
+        // Check the session supports it. If not we ignore it
+        if (SLANG_FAILED(spSessionHasCompileTargetSupport(context->getSession(), target)))
+        {
+            return TestResult::Ignored;
+        }
+
+        switch (target)
+        {
+            case SLANG_DXIL_ASM:
+            {
+                expectedSpawner.pushArgument(filePath + ".hlsl");
+                expectedSpawner.pushArgument("-pass-through");
+                expectedSpawner.pushArgument("dxc");
+                break;
+            }
+            default:
+            {
+                expectedSpawner.pushArgument(filePath + ".glsl");
+                expectedSpawner.pushArgument("-pass-through");
+                expectedSpawner.pushArgument("glslang");
+                break;
+            }
+        }
+    }
+   
     for( auto arg : input.testOptions->args )
     {
         actualSpawner.pushArgument(arg);
@@ -1960,7 +2008,13 @@ int main(
     }
 
     // Setup the context 
-    TestContext context(g_options.outputMode);
+    TestContext context;
+    if (SLANG_FAILED(context.init(g_options.outputMode)))
+    {
+        // Unable to initialize context
+        return 1;
+    }
+
     context.m_dumpOutputOnFailure = g_options.dumpOutputOnFailure;
     context.m_isVerbose = g_options.shouldBeVerbose;
 
diff --git a/tools/slang-test/slang-test.vcxproj b/tools/slang-test/slang-test.vcxproj
index acaa07d3e..13bf42141 100644
--- a/tools/slang-test/slang-test.vcxproj
+++ b/tools/slang-test/slang-test.vcxproj
@@ -180,6 +180,9 @@
     <ProjectReference Include="..\..\source\core\core.vcxproj">
       <Project>{F9BE7957-8399-899E-0C49-E714FDDD4B65}</Project>
     </ProjectReference>
+    <ProjectReference Include="..\..\source\slang\slang.vcxproj">
+      <Project>{DB00DA62-0533-4AFD-B59F-A67D5B3A0808}</Project>
+    </ProjectReference>
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
diff --git a/tools/slang-test/test-context.cpp b/tools/slang-test/test-context.cpp
index 158258873..b94435a8e 100644
--- a/tools/slang-test/test-context.cpp
+++ b/tools/slang-test/test-context.cpp
@@ -69,8 +69,8 @@ static void appendXmlEncode(const String& in, StringBuilder& out)
     }
 }
 
-TestContext::TestContext(TestOutputMode outputMode) :
-    m_outputMode(outputMode)
+TestContext::TestContext() :
+    m_outputMode(TestOutputMode::Default)
 {
     m_totalTestCount = 0;
     m_passedTestCount = 0;
@@ -82,6 +82,29 @@ TestContext::TestContext(TestOutputMode outputMode) :
     m_inTest = false;
     m_dumpOutputOnFailure = false;
     m_isVerbose = false;
+
+    m_session = nullptr;
+}
+
+Result TestContext::init(TestOutputMode outputMode)
+{
+    m_outputMode = outputMode;
+
+    m_session = spCreateSession(nullptr);
+    if (!m_session)
+    {
+        return SLANG_FAIL;
+    }
+
+    return SLANG_OK;
+}
+
+TestContext::~TestContext()
+{
+    if (m_session)
+    {
+        spDestroySession(m_session);
+    }
 }
 
 bool TestContext::canWriteStdError() const
@@ -601,4 +624,4 @@ void TestContext::endSuite()
     }
     
     m_suiteStack.RemoveLast();
-}
\ No newline at end of file
+}
diff --git a/tools/slang-test/test-context.h b/tools/slang-test/test-context.h
index 94f8c689f..a81473efa 100644
--- a/tools/slang-test/test-context.h
+++ b/tools/slang-test/test-context.h
@@ -124,8 +124,16 @@ class TestContext
         /// Returns true if all run tests succeeded
     bool didAllSucceed() const;
 
+        /// Get the slang session
+    SlangSession* getSession() const { return m_session;  }
+
+    SlangResult init(TestOutputMode outputMode);
+
         /// Ctor
-    TestContext(TestOutputMode outputMode);
+    TestContext();
+        /// Dtor
+    ~TestContext();
+
 
     static TestResult combine(TestResult a, TestResult b) { return (a > b) ? a : b; }
 
@@ -158,6 +166,8 @@ protected:
     int m_numFailResults;
 
     bool m_inTest;
+
+    SlangSession* m_session;
     
     static TestContext* s_context;
 };