Messages in this thread | ![/](/images/icornerl.gif) | | From | Namhyung Kim <> | Date | Tue, 9 Apr 2024 10:02:03 -0700 | Subject | Re: [PATCH] perf srcline: Implement addr2line using libdw |
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Hello,
On Thu, Apr 4, 2024 at 5:10 PM Martin Rodriguez Reboredo <yakoyoku@gmail.com> wrote: > > On 4/1/24 8:31 PM, Namhyung Kim wrote: > > [...] > > > > Thanks for doing this! Yep, we could unset the env temporarily. > > > > As a general comment, perf has some helper functions for libdw > > in util/dwarf-aux.[ch]. Please take a look and use/update them. > > Whoops! I haven't seen that file, thanks for mentioning it. > > > [...] > > > > Probably we can use cu_find_lineinfo(). > > I could use that, I'll see. > > > [...] > > > >>> +static struct a2l_data *addr2line_init(const char *path) > > > > debuginfo__new()? > > `libdw_a2l_new` can be another option too. > > > [...] > > > >>> +static int get_inline_function(struct dso *dso, struct inline_node *node, > >>> + struct symbol *sym) > >>> +{ > >>> + struct a2l_data *a2l = dso->a2l; > >>> + Dwarf_Addr addr = a2l->addr + a2l->bias; > >>> + Dwarf_Addr bias = 0; > >>> + Dwarf_Die *cudie = dwfl_module_addrdie(a2l->mod, addr, &bias); > >>> + > >>> + Dwarf_Die *scopes = NULL; > >>> + int nscopes = dwarf_getscopes(cudie, addr - bias, &scopes); > > > > It's not clear to me how this dwarf_getscopes() and later > > dwarf_getscopes_die() work together. Can you please add some > > comment? Also we have die_get_scopes() and I think it's simpler. > > I think the first is to get the scopes at an address and the second is > for the scopes with the addr offset at that DIE. Off the top of my head. > > > [...] > > > > Why not get the function name from the abstract origin? > > I'm not getting it, where's that abstract origin?
IIUC DW_TAG_inlined_subroutine has DW_AT_abstract_origin to point to the original definition of the function. It should have the name of the function.
<2><5ca8>: Abbrev Number: 40 (DW_TAG_inlined_subroutine) <5ca9> DW_AT_abstract_origin: <0x5eeb> <5cad> DW_AT_low_pc : 0x24efc6 <5cb5> DW_AT_high_pc : 0x2d <5cbd> DW_AT_call_file : 3 <5cbe> DW_AT_call_line : 135 <5cbf> DW_AT_call_column : 9
Thanks, Namhyung
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