[PATCH] D155545: [clang][Interp] Pass CallExpr to builtin functions

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added inline comments.


================
Comment at: clang/lib/AST/Interp/InterpBuiltin.cpp:78-79
+
+  if (!isa<StringLiteral>(Call->getArg(0)->IgnoreParenCasts()))
+    return false;
+
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Hmmm, I think I missed a situation when we were talking about this. Consider: https://godbolt.org/z/14dz5MMPj

I think the current interpreter is wrong to reject that code (I think the GCC behavior is correct). If you remove the `constexpr` from the declaration of `Nan2`, it compiles fine.

WDYT?


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Comment at: clang/test/AST/Interp/builtin-functions.cpp:44
 
-  constexpr float Nan2 = __builtin_nans([](){return "0xAE98";}()); // ref-error {{must be initialized by a constant expression}}
+  constexpr float Nan2 = __builtin_nans([](){return "0xAE98";}()); // ref-error {{must be initialized by a constant expression}} \
+                                                                   // expected-error {{must be initialized by a constant expression}}
----------------
I mentioned this on another review, but I think the current interpreter is wrong to reject this because that lambda is constexpr-suitable.

http://eel.is/c++draft/expr.prim.lambda#closure-5
http://eel.is/c++draft/dcl.constexpr#3


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  https://reviews.llvm.org/D155545/new/

https://reviews.llvm.org/D155545