Support generic constraints that are dependent on another generic param. (#4091)

2 files changed, 34 insertions, 6 deletions

diff --git a/source/slang/slang-ir-link.cpp b/source/slang/slang-ir-link.cpp
index 4871062d4..e652745e7 100644
--- a/source/slang/slang-ir-link.cpp
+++ b/source/slang/slang-ir-link.cpp
@@ -746,6 +746,12 @@ void cloneGlobalValueWithCodeCommon(
     {
         IRBlock* ob = originalValue->getFirstBlock();
         IRBlock* cb = clonedValue->getFirstBlock();
+        struct ParamCloneInfo
+        {
+            IRParam* originalParam;
+            IRParam* clonedParam;
+        };
+        ShortList<ParamCloneInfo> paramCloneInfos;
         while (ob)
         {
             SLANG_ASSERT(cb);
@@ -753,9 +759,28 @@ void cloneGlobalValueWithCodeCommon(
             builder->setInsertInto(cb);
             for (auto oi = ob->getFirstInst(); oi; oi = oi->getNextInst())
             {
-                cloneInst(context, builder, oi);
+                if (oi->getOp() == kIROp_Param)
+                {
+                    // Params may have forward references in its type and
+                    // decorations, so we just create a placeholder for it
+                    // in this first pass.
+                    IRParam* clonedParam = builder->emitParam(nullptr);
+                    registerClonedValue(context, clonedParam, oi);
+                    paramCloneInfos.add({ (IRParam*)oi, clonedParam });
+                }
+                else
+                {
+                    cloneInst(context, builder, oi);
+                }
+            }
+            // Clone the type and decorations of parameters after all instructs in the block
+            // have been cloned.
+            for (auto param : paramCloneInfos)
+            {
+                builder->setInsertInto(param.clonedParam);
+                param.clonedParam->setFullType((IRType*)cloneValue(context, param.originalParam->getFullType()));
+                cloneDecorations(context, param.clonedParam, param.originalParam);
             }
-
             ob = ob->getNextBlock();
             cb = cb->getNextBlock();
         }
diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index a78110a84..2bf5f1e96 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -8823,7 +8823,7 @@ struct DeclLoweringVisitor : DeclVisitor<DeclLoweringVisitor, LoweredValInfo>
         IRGenContext*               subContext,
         GenericTypeConstraintDecl*  constraintDecl)
     {
-        auto supType = lowerType(context, constraintDecl->sup.type);
+        auto supType = lowerType(subContext, constraintDecl->sup.type);
         auto value = emitGenericConstraintValue(subContext, constraintDecl, supType);
         subContext->setValue(constraintDecl, LoweredValInfo::simple(value));
     }
@@ -8972,9 +8972,11 @@ struct DeclLoweringVisitor : DeclVisitor<DeclLoweringVisitor, LoweredValInfo>
                 auto operand = value->getOperand(i);
                 markInstsToClone(valuesToClone, parentBlock, operand);
             }
+            if (value->getFullType())
+                markInstsToClone(valuesToClone, parentBlock, value->getFullType());
+            for (auto child : value->getDecorationsAndChildren())
+                markInstsToClone(valuesToClone, parentBlock, child);
         }
-        for (auto child : value->getChildren())
-            markInstsToClone(valuesToClone, parentBlock, child);
         auto parent = parentBlock->getParent();
         while (parent && parent != parentBlock)
         {
@@ -9025,7 +9027,8 @@ struct DeclLoweringVisitor : DeclVisitor<DeclLoweringVisitor, LoweredValInfo>
                 markInstsToClone(valuesToClone, parentGeneric->getFirstBlock(), returnType);
                 // For Function Types, we always clone all generic parameters regardless of whether
                 // the generic parameter appears in the function signature or not.
-                if (returnType->getOp() == kIROp_FuncType)
+                if (returnType->getOp() == kIROp_FuncType ||
+                    returnType->getOp() == kIROp_Generic)
                 {
                     for (auto genericParam : parentGeneric->getParams())
                     {