[PATCH] D108479: [Clang] Add __builtin_addressof_nocfi

[John McCall via Phabricator via cfe-commits]

rjmccall added a comment.

Your builtin is using custom type-checking (`t`), which suppresses all the normal conversions that happen on expressions.  Specifically, it skips lvalue-to-rvalue conversion, so in this example the argument ends up being an l-value reference to a variable rather than an r-value loaded from that variable.  In addition to confusing constant evaluation, it would also make this look like an ODR-use of the variable, which would be subtly wrong in some C++ cases.  The fix is to explicitly request the standard l-value conversions, which you can do with code like:

  ExprResult Arg = S.DefaultFunctionArrayLvalueConversion(TheCall->getArg(0));
  if (Arg.isInvalid()) return true;
  TheCall->setArg(0, Arg.get());

After that, constant-evaluating the argument expression in your example should give you a `FunctionDecl*` as expected.


Repository:
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  https://reviews.llvm.org/D108479/new/

https://reviews.llvm.org/D108479