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From: Jan Vrany <>
To: GDB mailing list <>
Subject: Hand-written assembly and Python API
Date: Fri, 29 Apr 2022 12:32:49 +0000	[thread overview]
Message-ID: <> (raw)

Hi folks,

I'm trying to debug a code that uses a handful of
hand-written assembly routines. For example, one of
them looks like (its RISC-V but that does not matter):

    .globl returnFromJIT1
    .type returnFromJIT1,function
    .align 2
    sd a0,248(s10)
    sd s11,32(s10)
    li a0, 17
    li a1, 1
    j cInterpreterFromJIT
    .size   returnFromJIT1, .-returnFromJIT1

   .globl ...

GDB clealy knows "something" about the assembly routines, it shows
the source properly and 'info symbol' works too:

   (gdb) info symbol 0x3ff75eca24
   returnFromJIT1 in section .text of /opt/riscv/sysroot/tmp/jdk/lib/default/

The problem is how to figure out I'm in (say) `returnFromJIT1` routine
using Python API:

   (gdb) py print(gdb.block_for_pc(0x3ff75eca24).function)

The only way I can think of is to parse value of `gdb.format_address()`:

   (gdb) py print(gdb.format_address(0x3ff75eca24))
   0x3ff75eca24 <returnFromJIT1>

which is bit awkward (but doable!).

Question is: is there a better way? I can modify the assembly source
too if there's some directive that may help GDB (.cfi_startproc / .cfi_endproc
is clearly not enough). Or do I have to roll up sleeves and implement python
API for minimal symbols?



             reply	other threads:[~2022-04-29 12:32 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-29 12:32 Jan Vrany [this message]
2022-04-29 12:54 ` Simon Marchi
2022-04-29 13:10   ` Jan Vrany

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