Dynamic dispatch for generic interface requirements.

-Lower interfaces into actual `IRInterfaceType` insts.
-Lower `DeclRef<AssocTypeDecl>` into `IRAssociatedType`
-Generate proper IRType for generic functions.
-Add a test case exercising dynamic dispatching a generic static function through an associated type.
-Bug fixes for the test case.

1 files changed, 17 insertions, 4 deletions

diff --git a/source/slang/slang-emit-c-like.cpp b/source/slang/slang-emit-c-like.cpp
index 3438fd3f4..2605723c7 100644
--- a/source/slang/slang-emit-c-like.cpp
+++ b/source/slang/slang-emit-c-like.cpp
@@ -236,9 +236,9 @@ List<IRWitnessTableEntry*> CLikeSourceEmitter::getSortedWitnessTableEntries(IRWi
     // Get a sorted list of entries using RequirementKeys defined in `interfaceType`.
     for (UInt i = 0; i < interfaceType->getOperandCount(); i++)
     {
-        auto reqKey = cast<IRStructKey>(interfaceType->getOperand(i));
+        auto reqEntry = cast<IRInterfaceRequirementEntry>(interfaceType->getOperand(i));
         IRWitnessTableEntry* entry = nullptr;
-        if (witnessTableEntryDictionary.TryGetValue(reqKey, entry))
+        if (witnessTableEntryDictionary.TryGetValue(reqEntry->getRequirementKey(), entry))
         {
             sortedWitnessTableEntries.add(entry);
         }
@@ -1962,6 +1962,10 @@ void CLikeSourceEmitter::defaultEmitInstExpr(IRInst* inst, const EmitOpInfo& inO
         are hashed with 'getStringHash' */
         break;
 
+    case kIROp_undefined:
+        m_writer->emit(getName(inst));
+        break;
+
     case kIROp_IntLit:
     case kIROp_FloatLit:
     case kIROp_BoolLit:
@@ -3554,6 +3558,11 @@ void CLikeSourceEmitter::emitGlobalInst(IRInst* inst)
         are hashed with 'getStringHash' */
         break;
 
+    case kIROp_InterfaceRequirementEntry:
+        // Don't emit anything for interface requirement at global level.
+        // They are handled in `emitInterface`.
+        break;
+
     case kIROp_Func:
         emitFunc((IRFunc*) inst);
         break;
@@ -3610,6 +3619,10 @@ void CLikeSourceEmitter::ensureInstOperandsRec(ComputeEmitActionsContext* ctx, I
     ensureInstOperand(ctx, inst->getFullType());
 
     UInt operandCount = inst->operandCount;
+    auto requiredLevel = EmitAction::Definition;
+    if (inst->op == kIROp_InterfaceType)
+        requiredLevel = EmitAction::ForwardDeclaration;
+
     for(UInt ii = 0; ii < operandCount; ++ii)
     {
         // TODO: there are some special cases we can add here,
@@ -3620,8 +3633,8 @@ void CLikeSourceEmitter::ensureInstOperandsRec(ComputeEmitActionsContext* ctx, I
         // only need the type they point to to be forward-declared.
         // Similarly, a `call` instruction only needs the callee
         // to be forward-declared, etc.
-
-        ensureInstOperand(ctx, inst->getOperand(ii));
+       
+        ensureInstOperand(ctx, inst->getOperand(ii), requiredLevel);
     }
 
     for(auto child : inst->getDecorationsAndChildren())