Make SlangSession an alias for slang::IGlobalSession (#1011)

* Make SlangSession an alias for slang::IGlobalSession.
Use asInternal/asExternal for casting in slang.cpp
Special case handling of asInternal which argument dependent lookup doesn't find.

* To improve implementation asInternal/asExternal in slang.cpp - tried making the internal impls forward to the Slang:: implementations. This caused ambiguities (for example when a function has using namespace Slang in it). To avoid these problems and make it clear where implementation is coming from use Slang::asInternal and removed the forwarding functions.
Made the impls SLANG_FORCE_INLINE instead of inline.

* Made asInternal/asExternal use SLANG_FORCE_INLINE uniformly.

3 files changed, 76 insertions, 74 deletions

diff --git a/slang.h b/slang.h
index 583072686..281aeba6a 100644
--- a/slang.h
+++ b/slang.h
@@ -1055,10 +1055,14 @@ extern "C"
     
     #define SLANG_UUID_ISlangWriter { 0xec457f0e, 0x9add, 0x4e6b,{ 0x85, 0x1c, 0xd7, 0xfa, 0x71, 0x6d, 0x15, 0xfd } };
 
+    namespace slang {
+    struct IGlobalSession;
+    } // namespace slang
+
     /*!
     @brief An instance of the Slang library.
     */
-    typedef struct SlangSession SlangSession;
+    typedef slang::IGlobalSession SlangSession;
 
     typedef struct SlangProgramLayout SlangProgramLayout;
 
diff --git a/source/slang/slang-compiler.h b/source/slang/slang-compiler.h
index 46b257fe3..8f9c20044 100644
--- a/source/slang/slang-compiler.h
+++ b/source/slang/slang-compiler.h
@@ -1943,66 +1943,76 @@ namespace Slang
 // abstract over the conversion required for each pair of types.
 //
 
-inline slang::IGlobalSession* asExternal(Session* session)
+SLANG_FORCE_INLINE slang::IGlobalSession* asExternal(Session* session)
 {
     return static_cast<slang::IGlobalSession*>(session);
 }
 
-inline slang::ISession* asExternal(Linkage* linkage)
+SLANG_FORCE_INLINE Session* asInternal(slang::IGlobalSession* session)
+{
+    return static_cast<Session*>(session);
+}
+
+SLANG_FORCE_INLINE slang::ISession* asExternal(Linkage* linkage)
 {
     return static_cast<slang::ISession*>(linkage);
 }
 
-inline Module* asInternal(slang::IModule* module)
+SLANG_FORCE_INLINE Module* asInternal(slang::IModule* module)
 {
     return static_cast<Module*>(module);
 }
 
-inline slang::IModule* asExternal(Module* module)
+SLANG_FORCE_INLINE slang::IModule* asExternal(Module* module)
 {
     return static_cast<slang::IModule*>(module);
 }
 
-inline ComponentType* asInternal(slang::IComponentType* componentType)
+SLANG_FORCE_INLINE ComponentType* asInternal(slang::IComponentType* componentType)
 {
     return static_cast<ComponentType*>(componentType);
 }
 
-inline slang::IComponentType* asExternal(ComponentType* componentType)
+SLANG_FORCE_INLINE slang::IComponentType* asExternal(ComponentType* componentType)
 {
     return static_cast<slang::IComponentType*>(componentType);
 }
 
-static inline slang::ProgramLayout* asExternal(ProgramLayout* programLayout)
+SLANG_FORCE_INLINE slang::ProgramLayout* asExternal(ProgramLayout* programLayout)
 {
     return (slang::ProgramLayout*) programLayout;
 }
 
-inline Type* asInternal(slang::TypeReflection* type)
+SLANG_FORCE_INLINE Type* asInternal(slang::TypeReflection* type)
 {
     return reinterpret_cast<Type*>(type);
 }
 
-inline slang::TypeReflection* asExternal(Type* type)
+SLANG_FORCE_INLINE slang::TypeReflection* asExternal(Type* type)
 {
     return reinterpret_cast<slang::TypeReflection*>(type);
 }
 
-inline TypeLayout* asInternal(slang::TypeLayoutReflection* type)
+SLANG_FORCE_INLINE TypeLayout* asInternal(slang::TypeLayoutReflection* type)
 {
     return reinterpret_cast<TypeLayout*>(type);
 }
 
-inline slang::TypeLayoutReflection* asExternal(TypeLayout* type)
+SLANG_FORCE_INLINE slang::TypeLayoutReflection* asExternal(TypeLayout* type)
 {
     return reinterpret_cast<slang::TypeLayoutReflection*>(type);
 }
 
-inline SlangCompileRequest* asExternal(EndToEndCompileRequest* request)
+SLANG_FORCE_INLINE SlangCompileRequest* asExternal(EndToEndCompileRequest* request)
 {
     return reinterpret_cast<SlangCompileRequest*>(request);
 }
 
+SLANG_FORCE_INLINE EndToEndCompileRequest* asInternal(SlangCompileRequest* request)
+{
+    return reinterpret_cast<EndToEndCompileRequest*>(request);
+}
+
 }
 
 #endif
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index b030e5cf9..cae9855e0 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -2442,21 +2442,9 @@ Session::~Session()
 
 // implementation of C interface
 
-static SlangSession* convert(Slang::Session* session)
-{ return reinterpret_cast<SlangSession*>(session); }
-
-static Slang::Session* convert(SlangSession* session)
-{ return reinterpret_cast<Slang::Session*>(session); }
-
-static SlangCompileRequest* convert(Slang::EndToEndCompileRequest* request)
-{ return reinterpret_cast<SlangCompileRequest*>(request); }
-
-static Slang::EndToEndCompileRequest* convert(SlangCompileRequest* request)
-{ return reinterpret_cast<Slang::EndToEndCompileRequest*>(request); }
-
 SLANG_API SlangSession* spCreateSession(const char*)
 {
-    return convert(new Slang::Session());
+    return asExternal(new Slang::Session());
 }
 
 SLANG_API SlangResult slang_createGlobalSession(
@@ -2476,7 +2464,7 @@ SLANG_API void spDestroySession(
     SlangSession*   session)
 {
     if(!session) return;
-    delete convert(session);
+    delete Slang::asInternal(session);
 }
 
 SLANG_API void spAddBuiltins(
@@ -2484,7 +2472,7 @@ SLANG_API void spAddBuiltins(
     char const*     sourcePath,
     char const*     sourceString)
 {
-    auto s = convert(session);
+    auto s = Slang::asInternal(session);
     s->addBuiltinSource(
 
         // TODO(tfoley): Add ability to directly new builtins to the approriate scope
@@ -2498,7 +2486,7 @@ SLANG_API void spSessionSetSharedLibraryLoader(
     SlangSession*               session,
     ISlangSharedLibraryLoader* loader)
 {
-    auto s = convert(session);
+    auto s = Slang::asInternal(session);
 
     if (!loader)
     {
@@ -2525,7 +2513,7 @@ SLANG_API void spSessionSetSharedLibraryLoader(
 SLANG_API ISlangSharedLibraryLoader* spSessionGetSharedLibraryLoader(
     SlangSession*               session)
 {
-    auto s = convert(session);
+    auto s = Slang::asInternal(session);
     return (s->sharedLibraryLoader == Slang::DefaultSharedLibraryLoader::getSingleton()) ? nullptr : s->sharedLibraryLoader.get();
 }
 
@@ -2533,7 +2521,7 @@ SLANG_API SlangResult spSessionCheckCompileTargetSupport(
     SlangSession*                session,
     SlangCompileTarget           target)
 {
-    auto s = convert(session);
+    auto s = Slang::asInternal(session);
     return Slang::checkCompileTargetSupport(s, Slang::CodeGenTarget(target));
 }
 
@@ -2541,16 +2529,16 @@ SLANG_API SlangResult spSessionCheckPassThroughSupport(
     SlangSession*       session,
     SlangPassThrough    passThrough)
 {
-    auto s = convert(session);
+    auto s = Slang::asInternal(session);
     return Slang::checkExternalCompilerSupport(s, Slang::PassThroughMode(passThrough));
 }
 
 SLANG_API SlangCompileRequest* spCreateCompileRequest(
     SlangSession* session)
 {
-    auto s = convert(session);
+    auto s = Slang::asInternal(session);
     auto req = new Slang::EndToEndCompileRequest(s);
-    return convert(req);
+    return asExternal(req);
 }
 
 /*!
@@ -2560,7 +2548,7 @@ SLANG_API void spDestroyCompileRequest(
     SlangCompileRequest*    request)
 {
     if(!request) return;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     delete req;
 }
 
@@ -2569,21 +2557,21 @@ SLANG_API void spSetFileSystem(
     ISlangFileSystem*       fileSystem)
 {
     if(!request) return;
-    convert(request)->getLinkage()->setFileSystem(fileSystem);
+    Slang::asInternal(request)->getLinkage()->setFileSystem(fileSystem);
 }
 
 SLANG_API void spSetCompileFlags(
     SlangCompileRequest*    request,
     SlangCompileFlags       flags)
 {
-    convert(request)->getFrontEndReq()->compileFlags = flags;
+    Slang::asInternal(request)->getFrontEndReq()->compileFlags = flags;
 }
 
 SLANG_API void spSetDumpIntermediates(
     SlangCompileRequest*    request,
     int                     enable)
 {
-    convert(request)->getBackEndReq()->shouldDumpIntermediates = enable != 0;
+    Slang::asInternal(request)->getBackEndReq()->shouldDumpIntermediates = enable != 0;
 }
 
 SLANG_API void spSetLineDirectiveMode(
@@ -2592,13 +2580,13 @@ SLANG_API void spSetLineDirectiveMode(
 {
     // TODO: validation
 
-    convert(request)->getBackEndReq()->lineDirectiveMode = Slang::LineDirectiveMode(mode);
+    Slang::asInternal(request)->getBackEndReq()->lineDirectiveMode = Slang::LineDirectiveMode(mode);
 }
 
 SLANG_API void spSetCommandLineCompilerMode(
     SlangCompileRequest* request)
 {
-    convert(request)->isCommandLineCompile = true;
+    Slang::asInternal(request)->isCommandLineCompile = true;
 
 }
 
@@ -2606,7 +2594,7 @@ SLANG_API void spSetCodeGenTarget(
         SlangCompileRequest*    request,
         SlangCompileTarget target)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->targets.clear();
     linkage->addTarget(Slang::CodeGenTarget(target));
@@ -2616,7 +2604,7 @@ SLANG_API int spAddCodeGenTarget(
     SlangCompileRequest*    request,
     SlangCompileTarget      target)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     return (int) linkage->addTarget(Slang::CodeGenTarget(target));
 }
@@ -2626,7 +2614,7 @@ SLANG_API void spSetTargetProfile(
     int                     targetIndex,
     SlangProfileID          profile)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->targets[targetIndex]->targetProfile = Slang::Profile(profile);
 }
@@ -2636,7 +2624,7 @@ SLANG_API void spSetTargetFlags(
     int                     targetIndex,
     SlangTargetFlags        flags)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->targets[targetIndex]->targetFlags = flags;
 }
@@ -2646,7 +2634,7 @@ SLANG_API void spSetTargetFloatingPointMode(
     int                     targetIndex,
     SlangFloatingPointMode  mode)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->targets[targetIndex]->floatingPointMode = Slang::FloatingPointMode(mode);
 }
@@ -2655,7 +2643,7 @@ SLANG_API void spSetMatrixLayoutMode(
     SlangCompileRequest*    request,
     SlangMatrixLayoutMode   mode)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->setMatrixLayoutMode(mode);
 }
@@ -2676,7 +2664,7 @@ SLANG_API void spSetDebugInfoLevel(
     SlangCompileRequest*    request,
     SlangDebugInfoLevel     level)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->debugInfoLevel = Slang::DebugInfoLevel(level);
 }
@@ -2688,7 +2676,7 @@ SLANG_API void spSetOptimizationLevel(
     SlangCompileRequest*    request,
     SlangOptimizationLevel  level)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->optimizationLevel = Slang::OptimizationLevel(level);
 }
@@ -2698,7 +2686,7 @@ SLANG_API void spSetOutputContainerFormat(
     SlangCompileRequest*    request,
     SlangContainerFormat    format)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     req->containerFormat = Slang::ContainerFormat(format);
 }
 
@@ -2707,7 +2695,7 @@ SLANG_API void spSetPassThrough(
     SlangCompileRequest*    request,
     SlangPassThrough        passThrough)
 {
-    convert(request)->passThrough = Slang::PassThroughMode(passThrough);
+    Slang::asInternal(request)->passThrough = Slang::PassThroughMode(passThrough);
 }
 
 SLANG_API void spSetDiagnosticCallback(
@@ -2718,7 +2706,7 @@ SLANG_API void spSetDiagnosticCallback(
     using namespace Slang;
 
     if(!request) return;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
 
     ComPtr<ISlangWriter> writer(new CallbackWriter(callback, userData, WriterFlag::IsConsole));
     req->setWriter(WriterChannel::Diagnostic, writer);
@@ -2730,7 +2718,7 @@ SLANG_API void spSetWriter(
     ISlangWriter*           writer)
 {
     if (!request) return;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
 
     req->setWriter(Slang::WriterChannel(chan), writer);
 }
@@ -2740,7 +2728,7 @@ SLANG_API ISlangWriter* spGetWriter(
     SlangWriterChannel      chan)
 {
     if (!request) return nullptr;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     return req->getWriter(Slang::WriterChannel(chan));
 }
 
@@ -2748,7 +2736,7 @@ SLANG_API void spAddSearchPath(
     SlangCompileRequest*    request,
     const char*             path)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->addSearchPath(path);
 }
@@ -2758,7 +2746,7 @@ SLANG_API void spAddPreprocessorDefine(
     const char*             key,
     const char*             value)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     linkage->addPreprocessorDefine(key, value);
 }
@@ -2767,7 +2755,7 @@ SLANG_API char const* spGetDiagnosticOutput(
     SlangCompileRequest*    request)
 {
     if(!request) return 0;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     return req->mDiagnosticOutput.begin();
 }
 
@@ -2778,7 +2766,7 @@ SLANG_API SlangResult spGetDiagnosticOutputBlob(
     if(!request) return SLANG_ERROR_INVALID_PARAMETER;
     if(!outBlob) return SLANG_ERROR_INVALID_PARAMETER;
 
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
 
     if(!req->diagnosticOutputBlob)
     {
@@ -2799,7 +2787,7 @@ SLANG_API int spAddTranslationUnit(
 {
     SLANG_UNUSED(name);
 
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
 
     return frontEndReq->addTranslationUnit(
@@ -2812,7 +2800,7 @@ SLANG_API void spTranslationUnit_addPreprocessorDefine(
     const char*             key,
     const char*             value)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
 
     frontEndReq->translationUnits[translationUnitIndex]->preprocessorDefinitions[key] = value;
@@ -2824,7 +2812,7 @@ SLANG_API void spAddTranslationUnitSourceFile(
     char const*             path)
 {
     if(!request) return;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
     if(!path) return;
     if(translationUnitIndex < 0) return;
@@ -2859,7 +2847,7 @@ SLANG_API void spAddTranslationUnitSourceStringSpan(
 {
     using namespace Slang;
     if(!request) return;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
     if(!sourceBegin) return;
     if(translationUnitIndex < 0) return;
@@ -2880,7 +2868,7 @@ SLANG_API void spAddTranslationUnitSourceBlob(
     ISlangBlob*             sourceBlob)
 {
     if(!request) return;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
     if(!sourceBlob) return;
     if(translationUnitIndex < 0) return;
@@ -2931,7 +2919,7 @@ SLANG_API int spAddEntryPointEx(
 {
     using namespace Slang;
     if (!request) return -1;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
     if (!name) return -1;
     if (translationUnitIndex < 0) return -1;
@@ -2952,7 +2940,7 @@ SLANG_API SlangResult spSetGlobalGenericArgs(
     char const**            genericArgs)
 {
     if (!request) return SLANG_FAIL;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
 
     auto& argStrings = req->globalSpecializationArgStrings;
     argStrings.clear();
@@ -2972,7 +2960,7 @@ SLANG_API SlangResult spSetTypeNameForGlobalExistentialTypeParam(
     if(slotIndex < 0)   return SLANG_FAIL;
     if(!typeName)       return SLANG_FAIL;
 
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto& typeArgStrings = req->globalSpecializationArgStrings;
     if(Index(slotIndex) >= typeArgStrings.getCount())
         typeArgStrings.setCount(slotIndex+1);
@@ -2992,7 +2980,7 @@ SLANG_API SlangResult spSetTypeNameForEntryPointExistentialTypeParam(
     if(slotIndex < 0)       return SLANG_FAIL;
     if(!typeName)           return SLANG_FAIL;
 
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     if(Index(entryPointIndex) >= req->entryPoints.getCount())
         return SLANG_FAIL;
 
@@ -3008,7 +2996,7 @@ SLANG_API SlangResult spSetTypeNameForEntryPointExistentialTypeParam(
 SLANG_API SlangResult spCompile(
     SlangCompileRequest*    request)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
 
 #if !defined(SLANG_DEBUG_INTERNAL_ERROR)
     // By default we'd like to catch as many internal errors as possible,
@@ -3063,7 +3051,7 @@ spGetDependencyFileCount(
     SlangCompileRequest*    request)
 {
     if(!request) return 0;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
     auto program = frontEndReq->getGlobalAndEntryPointsComponentType();
     return (int) program->getFilePathDependencies().getCount();
@@ -3077,7 +3065,7 @@ spGetDependencyFilePath(
     int                     index)
 {
     if(!request) return 0;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
     auto program = frontEndReq->getGlobalAndEntryPointsComponentType();
     return program->getFilePathDependencies()[index].begin();
@@ -3087,7 +3075,7 @@ SLANG_API int
 spGetTranslationUnitCount(
     SlangCompileRequest*    request)
 {
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto frontEndReq = req->getFrontEndReq();
     return (int) frontEndReq->translationUnits.getCount();
 }
@@ -3107,7 +3095,7 @@ SLANG_API void const* spGetEntryPointCode(
     size_t*                 outSize)
 {
     using namespace Slang;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     auto program = req->getSpecializedGlobalAndEntryPointsComponentType();
 
@@ -3162,7 +3150,7 @@ SLANG_API SlangResult spGetEntryPointCodeBlob(
     if(!request) return SLANG_ERROR_INVALID_PARAMETER;
     if(!outBlob) return SLANG_ERROR_INVALID_PARAMETER;
 
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     auto program = req->getSpecializedGlobalAndEntryPointsComponentType();
 
@@ -3214,7 +3202,7 @@ SLANG_API SlangResult spCompileRequest_getProgram(
     slang::IComponentType** outProgram)
 {
     if( !request ) return SLANG_ERROR_INVALID_PARAMETER;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto program = req->getSpecializedGlobalAndEntryPointsComponentType();
 
     *outProgram = Slang::ComPtr<slang::IComponentType>(program).detach();
@@ -3225,7 +3213,7 @@ SLANG_API SlangReflection* spGetReflection(
     SlangCompileRequest*    request)
 {
     if( !request ) return 0;
-    auto req = convert(request);
+    auto req = Slang::asInternal(request);
     auto linkage = req->getLinkage();
     auto program = req->getSpecializedGlobalAndEntryPointsComponentType();