Close https://github.com/llvm/llvm-project/issues/71034
See
https://discourse.llvm.org/t/rfc-c-20-modules-introduce-thin-bmi-and-decls-hash/74755
This patch introduces reduced BMI, which doesn't contain the definitions
of functions and variables if its definitions won't contribute to the
ABI.
Testing is a big part of the patch. We want to make sure the reduced BMI
contains the same behavior with the existing and relatively stable
fatBMI. This is pretty helpful for further reduction.
The user interfaces part it left to following patches to ease the
reviewing.
During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.
This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.
Drive-by fixes c++1z -> c++17 and c++2a -> c++20 when seen.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D149553
constrained friend".
When a friend declaration has a requires-clause, and either it's a
non-template function or it's a function template whose requires-clause
depends on an enclosing template parameter, it is member-like for the
purpose of redeclaration checking. Specifically, the lexically enclosing
class becomes part of its signature, so it can only be redeclared by
another declaration within the same class. In this change, we call such
functions "member-like constrained friends".
No functional change intended.
