.eh_frame section on alpha

[Richard Henderson]

On Wed, Jan 05, 2005 at 01:17:13PM +1100, Simon Burge wrote:
> Back to part of my original question - why did the .eh_frame section
> become mandatory on alpha when it doesn't appear to be on any other
> architecture?

Oh, but it does appear with other architectures.  x86-64, s390, and
ia64, at least.

> I'm not a C++ person, but I understood that this section was used
> with the exception handling mechanism.

Yes, but exceptions are the only reasonable way to implement POSIX
thread cancellation.  So we need to be able to handle exceptions
propagating through C and assembly code as well.

Alpha is (nearly) unique in that the original assembly language
specified directives from which unwind information can be derived.
Which meant that we don't have to go back and modify the assembly
specifically to add dwarf2 annotations to get things to work.


r~