[clang] [clang][CodeComplete] Recurse into the subexpression of deref operator in getApproximateType (PR #93404)

[Nathan Ridge via cfe-commits]

================
@@ -5680,8 +5680,16 @@ QualType getApproximateType(const Expr *E) {
     }
   }
   if (const auto *UO = llvm::dyn_cast<UnaryOperator>(E)) {
-    if (UO->getOpcode() == UnaryOperatorKind::UO_Deref)
-      return UO->getSubExpr()->getType()->getPointeeType();
+    if (UO->getOpcode() == UnaryOperatorKind::UO_Deref) {
+      // We recurse into the subexpression because it could be of dependent
+      // type.
+      QualType SubType = getApproximateType(UO->getSubExpr());
+      if (auto Pointee = SubType->getPointeeType(); !Pointee.isNull())
+        return Pointee;
+      // Our caller expects a non-null result, even though the SubType is
+      // supposed to have a pointee.
+      return SubType;
----------------
HighCommander4 wrote:

Perhaps falling through to the `return Unresolved` would be better? That's a dependent representation of the pointee type, so it seems less misleading than returning the pointer type. (And it's also what other branches in this function do.)

https://github.com/llvm/llvm-project/pull/93404