[PATCH] D80041: [clang-format] [PR45198] deletes whitespace inside of a noexcept specifier

[Jake Merdich via Phabricator via cfe-commits]

JakeMerdichAMD added a comment.

I mainly have concerns with the search for noexcept being too brittle and not looking far enough back. Implementing that may have performance implications though, so I have no issue ignoring that problem if it's proven sufficiently rare.

Also: should this do the same thing for throw()? It has pretty much the same constraints/context and would be trivial to add, although it's deprecated and/or removed in recent C++ versions. I'm not particularly inclined to implement that, but the question ought to be raised since it theoretically has the same problem.



================
Comment at: clang/lib/Format/TokenAnnotator.cpp:1933
+        if (PrevPrevToken) {
+          const FormatToken *PrevPrevPrevToken =
+              PrevPrevToken->getPreviousNonComment();
----------------
Doesn't this not handle nested templates? For example, `noexcept(Foo<Bar<T>>::value && Baz)` would not work here. Ditto on expressions like `Foo<T1, T2>`.

I'm having trouble thinking of a clean generic solution, but the most robust thing I can think of is to search the current line for the previous opening parens and check if noexcept is before it (if they use multiple sets of parens, the other heuristics seem to cover it). 


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D80041/new/

https://reviews.llvm.org/D80041