Re: [PATCH] Recognize branch instruction on MIPS in gdb.trace/entry-values.exp

Yao Qi
2014-12-30T12:34:10Z

"Maciej W. Rozycki" <macro@codesourcery.com> writes:

> What's the semantics of the test case and the changes you're making?
>

dwarf assembler is used to generate debug info with DW_TAG_GNU_call_site
and DW_TAG_GNU_call_site_parameter to exercise GDB. The change I am
making in this patch is to recognize branch instruction on MIPS, so that
we can compute the address returned from foo, and fill it in the
generated debug info.

> I'm asking because the MIPS architecture has several instructions used to
> make procedure calls, depending on the ISA and ABI selected, and also
> compiler options. Besides JAL these instructions include JALS, JALX,
> JALR, JALRC, JALRS, BAL and BALS. It looks to me you need to modify the
> pattern here to take these into account; JALRC does not have a delay slot.
>

I'll update the pattern to {jalrc|(?:jal|bal)[^\r\n]+\r\n}

>> All tests in entry-values.exp are PASS.
>
> Which target and ABI(s) did you ran your testing on? Please try at least
> these: o32/MIPS, o32/MIPS16, o32/microMIPS, n64 on a Linux and a
> bare-metal target each; testing o32/MIPS16 with the `-mflip-mips16' GCC
> option too will be appreciated. These combinations should trigger some
> (although not all) of the other possible instructions.

To avoid of misunderstanding, let me map them to the following concrete gcc
options (I don't find -mabi=o32 nor -mabi=n64 in
https://gcc.gnu.org/onlinedocs/gcc/MIPS-Options.html),

-mabi=32
-mabi=32 -mips16
-mabi=32 -mips16 -mflip-mips16
-mabi=32 -mmicromips
-mabi=64 on both linux and bare-metal target

are they what you want?

--
Yao (齐尧)