What is the “___emutls_get_address” symbol?

Question

Oh, I am a newbie in GCC and MAC and Makefile. Today I intended to build a dynamic lib using MAC OS X and GCC 4.4.2, but when linking the .o files, the compiler complains li

Answer 1

This symbol is part of TLS (thread-local storage) emulation by gcc for Mac Os X. There are some bugs in gcc bugzilla about this, e.g.: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39888

Using thread local storage (e.g. OpenMP ThreadPrivate variables) on Darwin requires manually linking to TLS emutls, via either -lgcc_s.so.1 or -lgcc_eh

See the threads: http://gcc.gnu.org/ml/gcc/2008-12/msg00145.html http://gcc.gnu.org/ml/gcc/2008-12/msg00107.html

From the above threads, this is evidently quite a mess. However, as I was just bit by this I hoped it useful to have a bug tracking the issue.

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TLS works fine if I manually link to gcc_s.so.1 or gcc_eh as mentioned above.

So, one of possible solutions is to add -lgcc_s.so.1 or -lgcc_eh option to linking step. And other is to update your gcc, because this is bug of gcc.