Fix intellisense and autodiff crashes. (#2879)

* Fix intellisense crash.

* Fix a bug in updateElement simplification.

* cleanup.

---------

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

2 files changed, 3 insertions, 1 deletions

diff --git a/source/slang/slang-ir-peephole.cpp b/source/slang/slang-ir-peephole.cpp
index e07d1f9c4..376795855 100644
--- a/source/slang/slang-ir-peephole.cpp
+++ b/source/slang/slang-ir-peephole.cpp
@@ -50,7 +50,7 @@ struct PeepholeContext : InstPassBase
                 return false;
 
             isAccessChainEqual = true;
-            for (UInt i = 0; i < (UInt)chainKey.getCount(); i++)
+            for (UInt i = 0; i < updateInst->getAccessKeyCount(); i++)
             {
                 if (updateInst->getAccessKey(i) != chainKey[i])
                 {
diff --git a/source/slang/slang-syntax.h b/source/slang/slang-syntax.h
index 3ac258f08..52df3a0e0 100644
--- a/source/slang/slang-syntax.h
+++ b/source/slang/slang-syntax.h
@@ -194,6 +194,8 @@ namespace Slang
 
     inline Type* getType(ASTBuilder* astBuilder, SubstExpr<Expr> expr)
     {
+        if (!expr)
+            return astBuilder->getErrorType();
         return substituteType(expr.getSubsts(), astBuilder, expr.getExpr()->type);
     }