[PATCH] D146408: [clang][Interp] Start supporting complex types

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman accepted this revision.
aaron.ballman added a comment.
This revision is now accepted and ready to land.

LGTM but perhaps we should add an expected-failing test case for the `_BitInt` situation just so we don't forget about it.



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Comment at: clang/lib/AST/Interp/PrimType.h:108
+    switch (Expr) {                                                            \
+      TYPE_SWITCH_CASE(PT_Sint8, B)                                            \
+      TYPE_SWITCH_CASE(PT_Uint8, B)                                            \
----------------
tbaeder wrote:
> aaron.ballman wrote:
> > Oh boy, this is going to be interesting, isn't it?
> > ```
> > consteval _Complex _BitInt(12) UhOh() { return (_Complex _BitInt(12))1; }
> > consteval _Complex _BitInt(18) Why() { return (_Complex _BitInt(18))1; }
> > 
> > static_assert(UhOh() + Why() == 2);
> > ```
> > 
> `_BitInt` isn't supported in the new interpreter at all right now, so this just gets rejected.
> 
> 
> Apart from that... is a complex bitint really something that should be supported? Not just in the new interpreter but generally?
> _BitInt isn't supported in the new interpreter at all right now, so this just gets rejected.

Well, that's sort of good then! :-D We'll have to deal with `_BitInt` at some point, so maybe we can add this as a test case with expected failures and a fixit comment so we don't forget about it?

> Apart from that... is a complex bitint really something that should be supported? Not just in the new interpreter but generally?

I don't see why not; we support complex integer types and `_BitInt` is an integer type. We support `_Complex` from C in C++ and we support `_BitInt` from C in C++, so it seems reasonable to expect `_Complex _BitInt` to work.


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https://reviews.llvm.org/D146408