On Mon, 14 Nov 2022 12:20:54 GMT, Julian Waters <jwat...@openjdk.org> wrote:
>> Sorry my eyes must be playing tricks on me. ?? >> >> Why did you need to add this here? > > It's to avoid redefining the linkage as static in os_windows.cpp (where it's > implemented) after an extern declaration (inside the class), which is > forbidden by C++11: > >> The linkages implied by successive declarations for a given entity shall >> agree. That is, within a given scope, each declaration declaring the same >> variable name or the same overloading of a function name shall imply the >> same linkage. > > While 2019 by default seems to ignore this rule and accepts the conflicting > linkage as a language extension, this can cause issues with newer and > stricter versions of the Visual C++ compiler (especially with -permissive- > passed during compilation, which Magnus and Daniel have pointed out in > another discussion will become the default mode of compilation in the > future). It's not possible to declare a static friend inside a class, so the > addition above takes advantage of another C++ feature instead: > >> ยง11.3/4 [class.friend] > A function first declared in a friend declaration has external linkage (3.5). > Otherwise, the function retains its previous linkage (7.1.1). I think the problem here is the friend declaration, which doesn't look like it's needed and could be deleted. ------------- PR: https://git.openjdk.org/jdk/pull/11081