[PATCH] D98912: Fix -Winteger-overflow to diagnose regardless of the top-level syntactic form.

[Volodymyr Sapsai via Phabricator via cfe-commits]

vsapsai added a comment.

Looks good to me. Have a few clarification questions.



================
Comment at: clang/lib/AST/ExprConstant.cpp:972-973
 
+    // Determine if we might warn that the given expression exhibits undefined
+    // behavior.
+    bool mightWarnOnUndefinedBehavior(const Expr *E) {
----------------
I'm not entirely sure but it can be useful to make it explicit in the comment the method doesn't deal with all the subexpressions recursively. Not convinced it is useful because don't have a good wording and you can get that information from the short method implementation. It is possible my suggestion is caused by checking the patch top-to-bottom without seeing how `mightWarnOnUndefinedBehavior` is used first, but that's not how developers would read the code later.


================
Comment at: clang/lib/AST/ExprConstant.cpp:8398-8399
 bool LValueExprEvaluator::VisitUnaryPreIncDec(const UnaryOperator *UO) {
-  if (!Info.getLangOpts().CPlusPlus14 && !Info.keepEvaluatingAfterFailure())
-    return Error(UO);
 
----------------
Just to confirm my understanding. There is no point in checking `keepEvaluatingAfterFailure` here because we are not short-circuiting anymore but can evaluate the expression in `VisitExpr(UO)`. And we still check `keepEvaluatingAfterFailure` in `SubexpressionVisitor::Run` in `EvaluateForDiagnostics`.


================
Comment at: clang/lib/Sema/SemaExpr.cpp:7125-7126
           << DestTy;
-      return CK_IntegralCast;
+      Src = ExprError();
+      return CK_Dependent;
     case Type::STK_CPointer:
----------------
What is the purpose of these changes to return `CK_Dependent`? Tests are passing without them and it's not obvious to me why do you need to change `CK_IntegralCast` to `CK_Dependent`.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D98912/new/

https://reviews.llvm.org/D98912