Fix crash when trying to constant fold non-existent call. (#3728)

2 files changed, 12 insertions, 0 deletions

diff --git a/source/slang/slang-check-expr.cpp b/source/slang/slang-check-expr.cpp
index 8b6fe76c7..ea6afdc1d 100644
--- a/source/slang/slang-check-expr.cpp
+++ b/source/slang/slang-check-expr.cpp
@@ -1424,6 +1424,8 @@ namespace Slang
         if (!funcDeclRefExpr) return nullptr;
 
         auto funcDeclRef = getDeclRef(m_astBuilder, funcDeclRefExpr);
+        if (!funcDeclRef)
+            return nullptr;
         auto intrinsicMod = funcDeclRef.getDecl()->findModifier<IntrinsicOpModifier>();
         auto implicitCast = funcDeclRef.getDecl()->findModifier<ImplicitConversionModifier>();
         if (!intrinsicMod && !implicitCast)
diff --git a/tests/bugs/gh-3727.slang b/tests/bugs/gh-3727.slang
new file mode 100644
index 000000000..89480d146
--- /dev/null
+++ b/tests/bugs/gh-3727.slang
@@ -0,0 +1,10 @@
+//TEST:SIMPLE(filecheck=CHECK): -target spirv -stage compute -entry main
+
+// CHECK: undefined identifier
+
+[shader("compute")]
+[numthreads(1, 1, 1)]
+void main(uint3 dtid : SV_DispatchThreadID)
+{    
+    const uint index = does_not_exist();
+}
\ No newline at end of file