Clean up type checking of higher order expressions. (#2519)

* Clean up type checking of higher order expressions.

* Replace `goto` with `break` to pacify clang.

* Fix.

* Fixes.

* Fix more tests.

* Fix lowerWitnessTable parameter error.

* Exclude attributes from ast printing.

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

1 files changed, 11 insertions, 0 deletions

diff --git a/source/slang/slang-ir-dce.cpp b/source/slang/slang-ir-dce.cpp
index d58e307da..14edf21d7 100644
--- a/source/slang/slang-ir-dce.cpp
+++ b/source/slang/slang-ir-dce.cpp
@@ -305,6 +305,17 @@ bool shouldInstBeLiveIfParentIsLive(IRInst* inst, IRDeadCodeEliminationOptions o
         {
             return true;
         }
+        if (inst->findDecoration<IRImportDecoration>())
+        {
+            if (inst->findDecoration<IRForwardDerivativeDecoration>())
+                return true;
+            if (auto genInst = as<IRGeneric>(inst))
+            {
+                auto inner = findInnerMostGenericReturnVal(genInst);
+                if (inner->findDecoration<IRForwardDerivativeDecoration>())
+                    return true;
+            }
+        }
     }
 
     if (options.keepLayoutsAlive && inst->findDecoration<IRLayoutDecoration>())