Re: find_pc_partial_function may produce the wrong answer

[Paul Koning <pkoning@equallogic.com>]

>>>>> "Daniel" == Daniel Jacobowitz <drow@false.org> writes:

 Daniel> On Wed, Jul 20, 2005 at 10:28:14AM -0400, Paul Koning wrote:
 >> I was tracking down a problem in my (modified) gdb, which showed
 >> up when doing callstack tracing by reading the prologue.
 >> (mips-tdep can do that, and in my version it does it most of the
 >> time.)
 >> 
 >> The problem is that find_pc_partial_function is used to find the
 >> start of the function, and it was producing the wrong answer.
 >> Specifically, it produces the wrong answer when the function is in
 >> a shared library.
 >> 
 >> The cause of the problem is that find_pc_partial_function looks up
 >> the symbol in the msymtab, and that contains only external
 >> symbols, not static symbols.  The comments in the source code
 >> explicitly claim that it DOES contain static symbols, but "maint
 >> print msymtab" clearly shows that it doesn't.  At least not for
 >> MIPS shared libraries...

 Daniel> Is the shared library stripped?  I am absolutely positive
 Daniel> that the minimal symbol table will include the static symtab
 Daniel> - as long as there is one.

 Daniel> If for some reason in your modified GDB this is not the case,
 Daniel> figure out why not.

It isn't related to the modified gdb; the stock gdb from CVS sources
does the same.

It looks instead like there is something bizarre going on in the
compile.  I looked in the build directory and found that the offending
file (malloc.o) has no static syms in its symbol table according to
readelf.  But when I repeat the compile by hand I get a rather
different looking symbol table that does have them.  Need to track
this down.

Thanks.

	paul