Re: patch: make the size of errbuf configurable

[Rich Felker <dalias@aerifal.cx>]

On Sun, May 19, 2013 at 04:12:58PM -0400, Z. Gilboa wrote:
> Greetings,
> 
> When a shared library that resides in a deeply nested folder
> contains unresolved (long-named, mangled) symbols, the displayed
> name of the library and/or symbol might get truncated.  The attached
> patch makes the size of errbuf (ldso/dynlink.c) configurable
> (--with-ld-errbuf-size), while yet leaving the default size of 128
> unaffected.

If at some point we do have build configurations, I'd want it to be
more structured, and for the user-visible names not to reflect
internal variable names, but something more meaningful to users.

With that said, in this case I think a different solution is called
for, mainly because having configurability for such small details is
setting a precedent that, if followed, could lead to hundreds of
trivial configurable knobs and the same testability nightmare that
plagues uClibc.

My preference is that either long pathnames should be truncated in a
reasonable way (keep in mind that the message is *not* parsable by the
caller; the only way it can be used is presenting it to the user) or
larger buffers should be dynamically allocated. The only reason I did
not go the dynamic-allocation path to begin with was to make it so
non-thread-safe usage of dlerror yields (at worst) corrupted messages
rather than crashes. This can also be achieved with dynamic allocation
(as long as the old too-short buffer is never freed), but it's more
complex.

I'd welcome input on which approach users would prefer.

Rich