Commit d7b60803 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf dwarf-aux: Add die_collect_global_vars() 



This function is to search all global variables in the CU.  We want to
have the list of global variables at once and match them later.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240502060011.1838090-2-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 8c618b58

tools/perf/util/dwarf-aux.c

+62 −0
Original line number Diff line number Diff line
@@ -1630,6 +1630,68 @@ void die_collect_vars(Dwarf_Die *sc_die, struct die_var_type **var_types) 


	die_find_child(sc_die, __die_collect_vars_cb, (void *)var_types, &die_mem);

}



static int __die_collect_global_vars_cb(Dwarf_Die *die_mem, void *arg)

{

	struct die_var_type **var_types = arg;

	Dwarf_Die type_die;

	int tag = dwarf_tag(die_mem);

	Dwarf_Attribute attr;

	Dwarf_Addr base, start, end;

	Dwarf_Op *ops;

	size_t nops;

	struct die_var_type *vt;



	if (tag != DW_TAG_variable)

		return DIE_FIND_CB_SIBLING;



	if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL)

		return DIE_FIND_CB_SIBLING;



	/* Only collect the location with an absolute address. */

	if (dwarf_getlocations(&attr, 0, &base, &start, &end, &ops, &nops) <= 0)

		return DIE_FIND_CB_SIBLING;



	if (ops->atom != DW_OP_addr)

		return DIE_FIND_CB_SIBLING;



	if (!check_allowed_ops(ops, nops))

		return DIE_FIND_CB_SIBLING;



	if (die_get_real_type(die_mem, &type_die) == NULL)

		return DIE_FIND_CB_SIBLING;



	vt = malloc(sizeof(*vt));

	if (vt == NULL)

		return DIE_FIND_CB_END;



	vt->die_off = dwarf_dieoffset(&type_die);

	vt->addr = ops->number;

	vt->reg = -1;

	vt->offset = 0;

	vt->next = *var_types;

	*var_types = vt;



	return DIE_FIND_CB_SIBLING;

}



/**

 * die_collect_global_vars - Save all global variables

 * @cu_die: a CU DIE

 * @var_types: a pointer to save the resulting list

 *

 * Save all global variables in the @cu_die and save them to @var_types.

 * The @var_types is a singly-linked list containing type and location info.

 * Actual type can be retrieved using dwarf_offdie() with 'die_off' later.

 *

 * Callers should free @var_types.

 */

void die_collect_global_vars(Dwarf_Die *cu_die, struct die_var_type **var_types)

{

	Dwarf_Die die_mem;



	die_find_child(cu_die, __die_collect_global_vars_cb, (void *)var_types, &die_mem);

}

#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */



#ifdef HAVE_DWARF_CFI_SUPPORT

tools/perf/util/dwarf-aux.h

+8 −0
Original line number Diff line number Diff line
@@ -171,6 +171,9 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr addr, 
/* Save all variables and parameters in this scope */

void die_collect_vars(Dwarf_Die *sc_die, struct die_var_type **var_types);



/* Save all global variables in this CU */

void die_collect_global_vars(Dwarf_Die *cu_die, struct die_var_type **var_types);



#else /*  HAVE_DWARF_GETLOCATIONS_SUPPORT */



static inline int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
@@ -203,6 +206,11 @@ static inline void die_collect_vars(Dwarf_Die *sc_die __maybe_unused, 
{

}



static inline void die_collect_global_vars(Dwarf_Die *cu_die __maybe_unused,

					   struct die_var_type **var_types __maybe_unused)

{

}



#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */



#ifdef HAVE_DWARF_CFI_SUPPORT