Re: RFA: don't use minsym name when searching block

Daniel Jacobowitz
2002-08-29T21:50:51Z

On Thu, Aug 29, 2002 at 04:24:16PM -0500, Jim Blandy wrote:
> Daniel Jacobowitz <drow@mvista.com> writes:
>
> > On Thu, Aug 22, 2002 at 12:26:51AM -0500, Jim Blandy wrote:
> > >
> > > I'd appreciate it if the C++ folks could check this out. I don't have
> > > a test case yet, but I'll try to put one together tomorrow.
> >
> > Could you describe the problem? Also... "the minsym's name might be
> > mangled" definitely seems like a problem; they should either be
> > consistently mangled or demangled...
>
> Minimal symbol names are consistently mangled, which makes sense:
> they're linker symbols, after all. You have to use
> SYMBOL_DEMANGLED_NAME to get a minsym's demangled name. But the names
> of real symbols (struct symbol) are always demangled. So when we pass
> SYMBOL_NAME (msymbol) to lookup_block_symbol, we're passing a name
> guaranteed to be mangled to a function that expects a demangled name.
>
> I'm working on a test case for this. The symptom is that, when you
> try to set a breakpoint on a method, say foo::bar, you get an error
> message, but if you then repeat the exact same command, it works the
> second time.

Oh! In that case, I think I have a test case for it tucked away in a
bug report; I'll look for it. That makes much more sense now.

> What's going on is that, the first time we call lookup_symbol_aux,
> which is passed both the mangled name and the demangled name, we hit
> the case being patched: we find a minsym, and read the symtab whose
> address range contains the minsym's value. However, since we then
> search the global and static blocks using the mangled name, we fail.
>
> The second time we try to lookup foo::bar, the symtab has been read,
> and the ALL_SYMTABS loop finds the symbol.

Thanks for the explanation. Shouldn't the code that does the same
thing in the (#&@ HPUXHPPA block further down have the same fix
applied? Other than that, it looks good to me.

--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer