On Tue, 3 Sep 2019, Martin Storsjö wrote:
On Tue, 3 Sep 2019, Liu Hao wrote:
在 2019/9/3 14:39, Martin Storsjö 写道:
In C++ mode, __mingw_ovr is a plain "inline" without "static".
Clang emits a standalone copy of functions in C++ for the combination
of non-static inline and __gnu_inline__, leading to multiple definitions
of symbols.
Signed-off-by: Martin Storsjö <mar...@martin.st>
---
mingw-w64-headers/crt/_mingw_mac.h | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
I understand what happened with clang but... isn't this clang's bug? It
is as expected that a out-of-line definition is emitted because inline
functions have external linkage in C++, which however should be
specified as `.weak` (on Linux etc.) and `.linkonce discard` on Windows.
So I am a bit curious how the multiple definition error could happen.
In this case, it doesn't get emitted as .linkonce discard - I'm not sure
exactly what's going on in this combination, whether it's contradicting
itself in C++ mode, or if it's just a bug.
I could take it up to try to fix it in clang, but so far, we've managed to
avoid inline + gnu_inline in C++ in our headers, so I would appreciate if
we could avoid this here as well, to work with contemporary clang versions
as well.
For the record, clang has had this behaviour wrt C++ since it got support
for gnu_inline in 2009, but it doesn't necessarily seem to be intentional.
I sent a patch for it at https://reviews.llvm.org/D67414, let's see how it
fares.
Regardless, as long as we want to support contempory versions of clang, we
need to avoid gnu_inline used without extern.
// Martin
_______________________________________________
Mingw-w64-public mailing list
Mingw-w64-public@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
