On Sat, Jun 29, 2019 at 2:04 PM Christos Zoulas <chris...@astron.com> wrote:
> In article <CAJeAr6vOWxv4ZxspYNMDeuP0U= > zccfacpsbmoz-4xguf54n...@mail.gmail.com>, > Andrew Cagney <andrew.cag...@gmail.com> wrote: > > > >Having 32-bit and 64-bit debuggers isn't sufficient. Specifically, it > >can't handle an exec() call where the new executable has a different > >ISA; and this imnsho is a must have. > > It is really hard to make a 32 bit debugger work on a 64 bit system > because of the tricks we play with the location of the shared > libraries in rtld and the debugger needs to be aware of them. > In retrospect it would have been simpler (and uglier) to have > /32 and /64 in all the shared library paths so that they would > not occupy the filesystem space, but even then things could break > for raw dlopen() calls, or opening other data files that are not > size neutral. HP/UX with Context Dependent Files and IBM/AIX with > Hidden Directories were attempts to a solution, but they created > a new dimension of problems. > I came to a similar conclusion when I hacked FreeBSD rtld to grok the difference between hard and soft float on the same system at the same time. Warner
