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Re: Fall back to a link test for TLS in target libraries
Daniel Jacobowitz wrote:
> On Wed, Nov 08, 2006 at 04:28:25PM -0500, Jakub Jelinek wrote:
>> This isn't sufficient, I'm afraid you need to link a shared library
>> rather than an executable. Because, at least for most targets __thread
>> uses in the executable will be local-exec (no matter what you declared
>> them as because of linker TLS optimizations), which doesn't need any
>> function calls. If you link a shared library and make sure it doesn't have
>> undefined symbols, then you should be safe. An extra complication is that
>> older glibcs didn't have ld.so in libc.so linker script and __tls_get_addr
>> is in glibc exported from ld.so.
> This test gets run on plenty of targets that don't even _have_ shared
> libraries. I'm trying to make a modest improvement in it, not a
> complete overhaul - so while I agree with all of this, I think that
> if the patch is appropriate, it's appropriate even without these
I agree. Since it doesn't look like anyone thinks the test makes
TLS-detection less accurate, and since it does certainly make it
somewhat more accurate on some targets, please go ahead.
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