Fix GLSL output for `gl_ClipDistance` input builtin. (#3193)

* Fix GLSL output for `gl_ClipDistance` input builtin.

* Fix.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

5 files changed, 90 insertions, 60 deletions

diff --git a/source/core/slang-signal.cpp b/source/core/slang-signal.cpp
index cdf2a1179..d8218b379 100644
--- a/source/core/slang-signal.cpp
+++ b/source/core/slang-signal.cpp
@@ -52,7 +52,7 @@ SLANG_RETURN_NEVER void handleSignal(SignalType type, char const* message)
     switch (type)
     {
         case SignalType::InvalidOperation:  throw InvalidOperationException(_getMessage(type, message));
-        case SignalType::AbortCompilation:  throw AbortCompilationException();
+        case SignalType::AbortCompilation:  throw AbortCompilationException(_getMessage(type, message));
         default:    throw InternalError(_getMessage(type, message));
     }
 #else
diff --git a/source/slang/slang-container-pool.h b/source/slang/slang-container-pool.h
index addeb1607..0b7a56694 100644
--- a/source/slang/slang-container-pool.h
+++ b/source/slang/slang-container-pool.h
@@ -25,7 +25,7 @@ struct ObjectPool
     {
         auto id = m_pool.alloc(1);
         if (id == -1)
-            SLANG_ABORT_COMPILATION("container pool allocation failure.");
+            SLANG_UNEXPECTED("container pool allocation failure.");
         return &m_objects[id];
     }
 
diff --git a/source/slang/slang-emit-glsl.cpp b/source/slang/slang-emit-glsl.cpp
index 94c85409f..c097de5b9 100644
--- a/source/slang/slang-emit-glsl.cpp
+++ b/source/slang/slang-emit-glsl.cpp
@@ -874,15 +874,15 @@ void GLSLSourceEmitter::_maybeEmitGLSLBuiltin(IRGlobalParam* var, UnownedStringS
     }
     else if (name == "gl_ClipDistance")
     {
+        // Is this an output? We do not need to define input.
         auto varType = var->getDataType();
         if (auto outType = as<IROutType>(varType))
         {
             varType = outType->getValueType();
+            m_writer->emit("out ");
+            emitType(varType, getName(var));
+            m_writer->emit(";\n\n");
         }
-
-        m_writer->emit("out ");
-        emitType(varType, getName(var));
-        m_writer->emit(";\n\n");
     }
 }
 
diff --git a/source/slang/slang-ir-glsl-legalize.cpp b/source/slang/slang-ir-glsl-legalize.cpp
index 4c5b58882..23ddfc50f 100644
--- a/source/slang/slang-ir-glsl-legalize.cpp
+++ b/source/slang/slang-ir-glsl-legalize.cpp
@@ -934,6 +934,65 @@ GLSLSystemValueInfo* getGLSLSystemValueInfo(
     return nullptr;
 }
 
+void createVarLayoutForLegalizedGlobalParam(
+    IRInst* globalParam,
+    IRBuilder* builder,
+    IRVarLayout* inVarLayout,
+    IRTypeLayout* typeLayout,
+    LayoutResourceKind kind,
+    UInt bindingIndex,
+    UInt bindingSpace,
+    GlobalVaryingDeclarator* declarator,
+    IRInst* leafVar,
+    GLSLSystemValueInfo* systemValueInfo)
+{
+    // We need to construct a fresh layout for the variable, even
+    // if the original had its own layout, because it might be
+    // an `inout` parameter, and we only want to deal with the case
+    // described by our `kind` parameter.
+    //
+    IRVarLayout::Builder varLayoutBuilder(builder, typeLayout);
+    varLayoutBuilder.cloneEverythingButOffsetsFrom(inVarLayout);
+    auto varOffsetInfo = varLayoutBuilder.findOrAddResourceInfo(kind);
+    varOffsetInfo->offset = bindingIndex;
+    varOffsetInfo->space = bindingSpace;
+    IRVarLayout* varLayout = varLayoutBuilder.build();
+    builder->addLayoutDecoration(globalParam, varLayout);
+
+    if (leafVar)
+    {
+        if (auto interpolationModeDecor = leafVar->findDecoration<IRInterpolationModeDecoration>())
+        {
+            builder->addInterpolationModeDecoration(globalParam, interpolationModeDecor->getMode());
+        }
+
+    }
+
+    if (declarator && declarator->flavor == GlobalVaryingDeclarator::Flavor::meshOutputPrimitives)
+    {
+        builder->addDecoration(globalParam, kIROp_GLSLPrimitivesRateDecoration);
+    }
+
+    if (systemValueInfo)
+    {
+        builder->addImportDecoration(globalParam, UnownedTerminatedStringSlice(systemValueInfo->name));
+
+        if (auto outerArrayName = systemValueInfo->outerArrayName)
+        {
+            builder->addGLSLOuterArrayDecoration(globalParam, UnownedTerminatedStringSlice(outerArrayName));
+        }
+
+        switch (systemValueInfo->kind)
+        {
+        case GLSLSystemValueKind::PositionOutput:
+            builder->addGLPositionOutputDecoration(globalParam);
+            break;
+        default:
+            break;
+        }
+    }
+}
+
 ScalarizedVal createSimpleGLSLGlobalVarying(
     GLSLLegalizationContext*    context,
     CodeGenContext*             codeGenContext,
@@ -975,9 +1034,9 @@ ScalarizedVal createSimpleGLSLGlobalVarying(
     {
         // If declarator is set we have a problem, because we can't have an array of arrays
         // so for now that's just an error
-        if (kind != LayoutResourceKind::VaryingOutput)
+        if (kind != LayoutResourceKind::VaryingOutput && kind != LayoutResourceKind::VaryingInput)
         {
-            SLANG_ABORT_COMPILATION("Can't handle anything but VaryingOutput.");
+            SLANG_UNIMPLEMENTED_X("Can't handle anything but VaryingOutput and VaryingInput.");
         }
 
         // Let's see if it has been already created
@@ -1005,17 +1064,18 @@ ScalarizedVal createSimpleGLSLGlobalVarying(
                 type,
                 0);
 
-            IRType* paramType = builder->getOutType(arrayType);
+            IRType* paramType = kind == LayoutResourceKind::VaryingOutput
+                ? (IRType*)builder->getOutType(arrayType)
+                : arrayType;
 
             auto globalParam = addGlobalParam(builder->getModule(), paramType);
             moveValueBefore(globalParam, builder->getFunc());
-
+            
             builder->addImportDecoration(globalParam, systemValueName);
 
-            // We can't run layout here, because we don't actually no the size yet
-            // We could run at the end though
+            createVarLayoutForLegalizedGlobalParam(
+                globalParam, builder, inVarLayout, inTypeLayout, kind, bindingIndex, bindingSpace, declarator, leafVar, systemValueInfo);
 
-            //
             semanticGlobalTmp.globalParam = globalParam;
 
             semanticGlobal = &context->systemNameToGlobalMap.getOrAddValue(systemValueName, semanticGlobalTmp); 
@@ -1107,18 +1167,6 @@ ScalarizedVal createSimpleGLSLGlobalVarying(
         }
     }
 
-    // We need to construct a fresh layout for the variable, even
-    // if the original had its own layout, because it might be
-    // an `inout` parameter, and we only want to deal with the case
-    // described by our `kind` parameter.
-    //
-    IRVarLayout::Builder varLayoutBuilder(builder, typeLayout);
-    varLayoutBuilder.cloneEverythingButOffsetsFrom(inVarLayout);
-    auto varOffsetInfo = varLayoutBuilder.findOrAddResourceInfo(kind);
-    varOffsetInfo->offset = bindingIndex;
-    varOffsetInfo->space = bindingSpace;
-    IRVarLayout* varLayout = varLayoutBuilder.build();
-
     // We are going to be creating a global parameter to replace
     // the function parameter, but we need to handle the case
     // where the parameter represents a varying *output* and not
@@ -1134,27 +1182,17 @@ ScalarizedVal createSimpleGLSLGlobalVarying(
     auto globalParam = addGlobalParam(builder->getModule(), paramType);
     moveValueBefore(globalParam, builder->getFunc());
 
-    if( leafVar )
-    {
-        if( auto interpolationModeDecor = leafVar->findDecoration<IRInterpolationModeDecoration>() )
-        {
-            builder->addInterpolationModeDecoration(globalParam, interpolationModeDecor->getMode());
-        }
-    }
-
     ScalarizedVal val = isOutput ? ScalarizedVal::address(globalParam) : ScalarizedVal::value(globalParam);
 
-    if( systemValueInfo )
+    if (systemValueInfo)
     {
-        builder->addImportDecoration(globalParam, UnownedTerminatedStringSlice(systemValueInfo->name));
-
-        if( auto fromType = systemValueInfo->requiredType )
+        if (auto fromType = systemValueInfo->requiredType)
         {
             // We may need to adapt from the declared type to/from
             // the actual type of the GLSL global.
             auto toType = inType;
 
-            if( !isTypeEqual(fromType, toType ))
+            if (!isTypeEqual(fromType, toType))
             {
                 RefPtr<ScalarizedTypeAdapterValImpl> typeAdapter = new ScalarizedTypeAdapterValImpl;
                 typeAdapter->actualType = systemValueInfo->requiredType;
@@ -1164,29 +1202,10 @@ ScalarizedVal createSimpleGLSLGlobalVarying(
                 val = ScalarizedVal::typeAdapter(typeAdapter);
             }
         }
-
-        if(auto outerArrayName = systemValueInfo->outerArrayName)
-        {
-            builder->addGLSLOuterArrayDecoration(globalParam, UnownedTerminatedStringSlice(outerArrayName));
-        }
-
-        switch (systemValueInfo->kind)
-        {
-        case GLSLSystemValueKind::PositionOutput:
-            builder->addGLPositionOutputDecoration(globalParam);
-            break;
-        default:
-            break;
-        }
     }
 
-    if(declarator && declarator->flavor == GlobalVaryingDeclarator::Flavor::meshOutputPrimitives)
-    {
-        builder->addDecoration(globalParam, kIROp_GLSLPrimitivesRateDecoration);
-    }
-
-    builder->addLayoutDecoration(globalParam, varLayout);
-
+    createVarLayoutForLegalizedGlobalParam(
+        globalParam, builder, inVarLayout, typeLayout, kind, bindingIndex, bindingSpace, declarator, leafVar, systemValueInfo);
     return val;
 }
 
@@ -1828,6 +1847,11 @@ IRInst* materializeValue(
         }
         break;
 
+    case ScalarizedVal::Flavor::arrayIndex:
+        {
+            auto element = builder->emitElementExtract(val.irValue, as<ScalarizedArrayIndexValImpl>(val.impl)->index);
+            return element;
+        }
     case ScalarizedVal::Flavor::tuple:
         {
             //auto tupleVal = as<ScalarizedTupleValImpl>(val.impl);
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index ae008cebb..38ebcccd6 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -5287,11 +5287,17 @@ SlangResult EndToEndCompileRequest::EndToEndCompileRequest::compile()
     {
         res = executeActions();
     }
-    catch (const AbortCompilationException&)
+    catch (const AbortCompilationException& e)
     {
         // This situation indicates a fatal (but not necessarily internal) error
         // that forced compilation to terminate. There should already have been
         // a diagnostic produced, so we don't need to add one here.
+        if (getSink()->getErrorCount() == 0)
+        {
+            // If for some reason we didn't output any diagnostic, something is
+            // going wrong, but we want to make sure we at least output something.
+            getSink()->diagnose(SourceLoc(), Diagnostics::compilationAbortedDueToException, typeid(e).name(), e.Message);
+        }
     }
     catch (const Exception& e)
     {