perf dwarf-aux: Add die_find_variable_by_addr()

The die_find_variable_by_addr() is to find a variables in the given DIE
using given (PC-relative) address.  Global variables will have a
location expression with DW_OP_addr which has an address so can simply
compare it with the address.

  <1><143a7>: Abbrev Number: 2 (DW_TAG_variable)
      <143a8>   DW_AT_name        : loops_per_jiffy
      <143ac>   DW_AT_type        : <0x1cca>
      <143b0>   DW_AT_external    : 1
      <143b0>   DW_AT_decl_file   : 193
      <143b1>   DW_AT_decl_line   : 213
      <143b2>   DW_AT_location    : 9 byte block: 3 b0 46 41 82 ff ff ff ff
                                     (DW_OP_addr: ffffffff824146b0)

Note that the type-offset should be calculated from the base address of
the global variable.

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions