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Re: [ppc64 help] Convert breakpoint's into addresses


On Sep 19,  3:40pm, Andrew Cagney wrote:

> I think the ppc64 ELF ABI is officially wierd.
> 
> For "main" the minimal symbol table contains two symbols vis:
> 
> 	main: points at descriptor in .opd sectoin
> 	.main: points at main's code entry point
> 
> Consequently, given only a minimal symbol table, GDB, when given:
> 
> 	(gdb) break main
> 
> will try to insert the breakpoint in the descriptor, and not the 
> function.  Trying to enter:
> 
> 	(gdb) break .main
> 
> gets you no where (syntax error :-/)
> 
> Adding to the fun, GCC's debug info contains the symbol "main" which 
> points at the code address (and not the descriptor) and consequently 
> debugging with symbols works.  Yes, this means that "main" has two 
> different values, arrrghghgh!!

Yuck.  Is gcc simply broken or is there a good reason to do things this
way?

> Attatched is a hack to breakpoint.c that applies "convert from func ptr 
> addr" to any address.  This causing the breakpoint code to convert 
> "main" into ".main" and hence work.
> 
> I don't know if its a right fix, good fix, or of any other alternative 
> fix.  However it does work ...

> help!
> 
> 2003-09-17  Andrew Cagney  <cagney@redhat.com>
> 
> 	* breakpoint.c (set_raw_breakpoint): Apply
> 	CONVERT_FROM_FUNC_PTR_ADDR to the breakpoint address.
> 	(breakpoint_re_set_one): Ditto.

I can't think of anything better.  If this goes in, I suggest adding
a nice fat comment explaining what's going on...

Kevin


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