Re: [PATCH v2] gdb: CTF support

[Simon Marchi <simark@simark.ca>]

Hi Weimin,

I'd like to give this a try and review this, but I hit a wall.  I compiled
gcc with this patch series (v5) applied:

  https://gcc.gnu.org/ml/gcc-patches/2019-09/msg00457.html

I am able to compile a simple .c file with -gt, and the resulting
binary contains a .ctf section.  But when loading the file in GDB,
I get this:

  (gdb) file a.out
  Reading symbols from a.out...
  ctf_bfdopen failed on /home/simark/build/binutils-gdb/gdb/a.out - File data structure corruption detected

The error occurs in ctf_bufopen, at line 1294:

  1294	  if (hp.cth_lbloff > hp.cth_objtoff
  1295	      || hp.cth_objtoff > hp.cth_funcoff
  1296	      || hp.cth_funcoff > hp.cth_typeoff
  1297	      || hp.cth_funcoff > hp.cth_varoff
  1298	      || hp.cth_varoff > hp.cth_typeoff || hp.cth_typeoff > hp.cth_stroff)
  1299	    return (ctf_set_open_errno (errp, ECTF_CORRUPT));

`hp` is:

  $10 = {
    cth_preamble = {
      ctp_magic = 57330,
      ctp_version = 4 '\004',
      ctp_flags = 0 '\000'
    },
    cth_parlabel = 0,
    cth_parname = 0,
    cth_lbloff = 10,
    cth_objtoff = 0,
    cth_funcoff = 0,
    cth_varoff = 0,
    cth_typeoff = 12,
    cth_stroff = 12,
    cth_strlen = 16
  }

The program I compiled is:

  int main() {
      return 2;
 }

compiled with:

  /data/scratch/gcc-install/bin/gcc test.c -gt -O0


On 2019-07-30 7:43 p.m., Weimin Pan wrote:
> [Changes from v1:
>  - Add libctf dependencies in Makefile.def and Makefile.in.
>  - Use type-safe registry API for per-objfile data ctf_tid_key.
>  - Replace buildsym-legacy.h with buildsym.h.
>  - Use xcalloc/xfree to allocate hash tables.
>  - Use get_global_symbols() instead of get_file_symbols() to add symbols.
>  - Rename gdb/ctf.h to /gdb/tracectf.h.]

Could you please rename ctf.c to tracectf.c as well?  It's much easier when the
corresponding .c and .h are named the same way.  I'd also like if you did that
renaming it a separate, preparatory patch, just to keep each patch focused.

Simon