Re: mips-tdep.c: Adjust breakpoints in branch delay slots

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> Date: Thu, 24 May 2007 19:07:46 +0100 (BST)
> From: "Maciej W. Rozycki" <macro@mips.com>
> 
> Hello,
> 
>  This is a change that makes breakpoints requested in a branch or jump 
> delay slot be moved to the preceding instruction.  This removes a 
> confusion that arises when such a breakpoint is hit and the resulting 
> message like this:
> 
> (gdb) break *0x00400670
> Breakpoint 1 at 0x400670: file foo.c, line 12.
> (gdb) run
> Starting program: .../foo
> 
> Program received signal SIGTRAP, Trace/breakpoint trap.
> main (argc=1, argv=0x7fd7c874) at foo.c:12
> 12      }
> (gdb) x /2i $pc
> 0x40066c <main+12>:     jr      ra
> 0x400670 <main+16>:     move    v0,zero
> 
>  This change has been tested natively for mips-unknown-linux-gnu and 
> remotely for mipsisa32-sde-elf, using mips-sim-sde32/-EB, 
> mips-sim-sde32/-mips16/-EB, mips-sim-sde32/-EL and 
> mips-sim-sde32/-mips16/-EL as the targets, with no regressions.
> 
> 2007-05-24  Chris Dearman  <chris@mips.com>
>             Maciej W. Rozycki  <macro@mips.com>
> 
> 	* mips-tdep.c (mips32_instruction_has_delay_slot): New function.
> 	(mips16_instruction_has_delay_slot): Likewise.
> 	(mips_segment_boundary): Likewise.
> 	(mips_adjust_breakpoint_address): Likewise.
> 	(mips_gdbarch_init): Use mips_adjust_breakpoint_address.
> 
>  OK to apply?

Do we have a testcase for this?  I also would like to test this on
OpenBSD/mips64.  Unfortunately I won't be able to test this in the
next three weeks.  Can this wait until then?