[PATCH] D142388: [clang] Add builtin_nondet

[Erich Keane via Phabricator via cfe-commits]

erichkeane added inline comments.


================
Comment at: clang/include/clang/Basic/Builtins.def:658
 BUILTIN(__builtin_call_with_static_chain, "v.", "nt")
+BUILTIN(__builtin_nondet, "v.", "nt")
 
----------------
aaron.ballman wrote:
> aaron.ballman wrote:
> > shafik wrote:
> > > erichkeane wrote:
> > > > Not a fan of the name in general, it doesn't really explain what is happening.  Perhaps `__builtin_nondeterministic_value` or something?  
> > > > 
> > > > I also wonder if others might have a better name :) 
> > > `__builtin_indeterminate_value` wdyt?
> > I think `__builtin_unspecified_value()` makes sense, as that's what you're getting back (there is a valid value, but you may get a different value on every call). I don't think `indeterminate` makes sense because that implies it may return trap values, and I'm guessing that's not behavior we want here (or am I wrong about that)?
> > 
> > Also, should this be usable within a constant expression? I would assume not; we should have a test case showing you can't use it in such a context.
> Why does this require custom typechecking?
Our issue last time with "unspecified" value was that this has a distinct meaning in C/C++, so we don't want to use that word.  


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142388/new/

https://reviews.llvm.org/D142388