Re: [patch/rfa] Allow breakpoing to be added after inferior has started

[Daniel Jacobowitz <drow@false.org>]

On Fri, May 21, 2004 at 07:31:33PM -0700, Randolph Chung wrote:
> The shlib-call.exp test fails on hppa (also ia64) because it tries to 
> add a breakpoint before the inferior is started, so there's no where 
> to put the breakpoint. gdb can handle this case if we allow pending 
> breakpoints in the test.
> 
> this only works on x86 and some other architectures because they put
> instructions into the plt; but some architectures put addresses in the
> plt.

This is a naming issue only.  Some architectures call the table of
addresses the PLT and have another fancy name for the stubs; other
architectures put the table of addresses in .got.plt in the GOT, and
call the stubs "PLT entries".  Your import stub serves the same purpose
as a PLT entry "normally" would.

This is why I was so confused by your explanation - PLT slots are
"normally" code :)

The difference on HPPA is that the undefined symbol for printf has a
value of 0 instead of a value pointing at the beginning of the import
stub.  Some other architectures do this also.  It's a generally
legitimate thing to do; if we worked really hard at it, we could
reconstruct the address of the import stub by grubbing around in the
text section, symbols, and relocations, but it would be quite
complicated.

> 
> ok to commit?
> 
> randolph
> 
> 2004-05-21  Randolph Chung  <tausq@debian.org>
> 
> 	* gdb.base/shlib-call.exp: Allow breakpoint to be added after inferior
> 	has started.

OK.

-- 
Daniel Jacobowitz