RFC: Access TLS symbols without DWARF debuginfo

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

Hi,

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=185337

currently if you have threaded (-lpthread) program compiled without debuginfo
"-g" and you try to access TLS symbol you will get:
	(gdb) print thread_local
	Cannot access memory at address 0x0

as gdb tries to resolve TLS-offset as absolute memory reference.

In fact it occurs if you try to access "errno" on -lpthread program with
debuginfo lower than -ggdb3.

Attached patch implements accessing them without the debuginfo suggestions as
not always such associatet debuginfo is available.  It checks for
	SYMBOL_BFD_SECTION (msymbol)->flags & SEC_THREAD_LOCAL
symbols, implements for them new `UNOP_MEMVAL_TLS' and reuses for them former
`dwarf_expr_tls_address'.



Regards,
Jan.

Attachment: gdb-6.5-bz185337-resolve-tls-without-debuginfo.patch
Description: Text document