aaron.ballman added a comment. In D31413#2277985 <https://reviews.llvm.org/D31413#2277985>, @ldionne wrote:
> In D31413#2277630 <https://reviews.llvm.org/D31413#2277630>, @smeenai wrote: > >> What was the conclusion for the comments about the priority level (100 vs. >> 101)? > > My understanding is that values below `101` are literally not allowed: > > <...>/llvm/libcxx/src/iostream.cpp:80:66: error: 'init_priority' attribute > requires integer constant between 101 and 65535 inclusive > _LIBCPP_HIDDEN ios_base::Init __start_std_streams > __attribute__((init_priority(100))); > ^ > ~~~ > 1 error generated. > > If there's a way around that, and if values below 101 are reserved for the > implementation, then I agree `100` is what we should use. @aaron.ballman > where did you read that values below 101 were reserved for the implementation? From GCC itself: https://godbolt.org/z/zajPsj but also from libstdc++ maintainers https://gcc.gnu.org/legacy-ml/gcc-help/2014-08/msg00117.html > The GCC docs at > https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Attributes.html don't imply > that -- they say the attribute starts at 101. I agree it's a fairly logical > thing to think values before that would be reserved, but it doesn't say > explicitly. > > Is it possible that GCC reserves values before 101 for the implementation, > but Clang implemented the attribute "naively" and just errors out? Yes, and the way I would handle this is to change the `init_priority` value checking to allow values <= 100 if the attribute location is within a system header. This would allow libc++ to use the reserved priority but would still give errors when attempted from user code. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D31413/new/ https://reviews.llvm.org/D31413 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
