[PATCH] D23820: Do not warn about format strings that are indexed string literals.

[Meike Baumgärtner via cfe-commits]

meikeb added inline comments.

================
Comment at: lib/Sema/SemaChecking.cpp:4089-4090
@@ +4088,4 @@
+    if (BinOp->isAdditiveOp()) {
+      bool LIsInt = BinOp->getLHS()->EvaluateAsInt(LResult, S.Context);
+      bool RIsInt = BinOp->getRHS()->EvaluateAsInt(RResult, S.Context);
+
----------------
rsmith wrote:
> What happens if one of these expressions is value-dependent? The evaluator can crash or assert if given a value-dependent expression. If we don't defer these checks in dependent contexts, you'll need to handle that possibility somehow.
> 
> Example:
> 
>   template<int N> void f(const char *p) {
>     printf("blah blah %s" + N, p);
>   }
I think I don't understand what you are trying to tell me. Especially the example you provided does just fine and behaves as I expected. As far as I followed EvaluateAsInt it does not assert but returns false if we don't get a constexpr here. We warn under -Wformat-nonliteral for value-dependent string literals.

Could you explain this more or provide an example that triggers an assert or explain what behavior is wrong regarding the provided example? Thanks! 


https://reviews.llvm.org/D23820