> To Szabolcs Nagy: that's not how abi works...
1. I know, what i meant, is that: these symbols seems only called by stdc++ themselves, i havnt seen any program invoke these symbols directly, they use std::locale() or something else. At least in my system, schroot does not need to recompile, neither chromium, they worked well just after i patched the toolchain. It's worth to checking if these symbols is used by other binaries out of stdc++, if just 1 or 2, or even no, it's not a big deal to apply this patch.

But now i change my mind, as you said, this not a perfect solution, indeed there's a risk of breaking binaries. If it is on the way of upstreaming the patch, i wont do like this.

> To Rich: So would this work?...
2. let me try it. :)

2017-01-30 0:40 GMT+08:00 Szabolcs Nagy <nsz@port70.net>:
* He X <xw897002528@gmail.com> [2017-01-29 22:48:34 +0800]:
> 2. no other ways, musl will use generic config 100%, and then the
> exception, the run time error is hardcoded there; but i doubt if this
> really breaks binaries, the function is only called by libstdc++ itself.
> you cant only update the config, but does not update libstdc++. libstdc++
> exported the same abi for common binaries, wont break most dynamic-loaded
> binary in my view.

that's not how abi works.. you change the __c_locale typedef
of the generic config from int* to locale_t, such change
breaks abi and cannot be upstreamed to gcc. (it's unfortunate
that the c++ locale handling default for non-gnu systems
does not use posix locales correctly, but breaking abi
for all non-gnu systems is not an acceptable fix.)

with your change the abi of libstdc++ would look like
the current gnu abi:

$ grep __locale_struct libstdc++-v3/config/abi/post/x86_64-linux-gnu/baseline_symbols.txt |wc -l
72

the abi on a musl based system is like

$ nm -D /usr/lib/libstdc++.so.6 |grep __locale_struct |wc -l
0

so with your patch if a compiled binary refers to any one
of those 72 symbols then the dynamic linker will fail to
load it on a musl based system.