perf probe: Introduce die_find_child() function

Introduce die_find_child() function to integrate DIE-tree
searching functions.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100316220558.32050.7905.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index c91a960..3942e14 100644 (file)
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -186,6 +186,62 @@ static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname)
        return src;
 }
 
+/* Compare diename and tname */
+static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
+{
+       const char *name;
+       name = dwarf_diename(dw_die);
+       DIE_IF(name == NULL);
+       return strcmp(tname, name);
+}
+
+/* Get entry pc(or low pc, 1st entry of ranges)  of the die */
+static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die)
+{
+       Dwarf_Addr epc;
+       int ret;
+
+       ret = dwarf_entrypc(dw_die, &epc);
+       DIE_IF(ret == -1);
+       return epc;
+}
+
+/* Return values for die_find callbacks */
+enum {
+       DIE_FIND_CB_FOUND = 0,          /* End of Search */
+       DIE_FIND_CB_CHILD = 1,          /* Search only children */
+       DIE_FIND_CB_SIBLING = 2,        /* Search only siblings */
+       DIE_FIND_CB_CONTINUE = 3,       /* Search children and siblings */
+};
+
+/* Search a child die */
+static Dwarf_Die *die_find_child(Dwarf_Die *rt_die,
+                                int (*callback)(Dwarf_Die *, void *),
+                                void *data, Dwarf_Die *die_mem)
+{
+       Dwarf_Die child_die;
+       int ret;
+
+       ret = dwarf_child(rt_die, die_mem);
+       if (ret != 0)
+               return NULL;
+
+       do {
+               ret = callback(die_mem, data);
+               if (ret == DIE_FIND_CB_FOUND)
+                       return die_mem;
+
+               if ((ret & DIE_FIND_CB_CHILD) &&
+                   die_find_child(die_mem, callback, data, &child_die)) {
+                       memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
+                       return die_mem;
+               }
+       } while ((ret & DIE_FIND_CB_SIBLING) &&
+                dwarf_siblingof(die_mem, die_mem) == 0);
+
+       return NULL;
+}
+
 struct __addr_die_search_param {
        Dwarf_Addr      addr;
        Dwarf_Die       *die_mem;
@@ -217,77 +273,45 @@ static Dwarf_Die *die_find_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr,
                return die_mem;
 }
 
-/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
-static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
-                                     Dwarf_Die *die_mem)
+/* die_find callback for inline function search */
+static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data)
 {
-       Dwarf_Die child_die;
-       int ret;
+       Dwarf_Addr *addr = data;
 
-       ret = dwarf_child(sp_die, die_mem);
-       if (ret != 0)
-               return NULL;
-
-       do {
-               if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
-                   dwarf_haspc(die_mem, addr))
-                       return die_mem;
+       if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&
+           dwarf_haspc(die_mem, *addr))
+               return DIE_FIND_CB_FOUND;
 
-               if (die_find_inlinefunc(die_mem, addr, &child_die)) {
-                       memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
-                       return die_mem;
-               }
-       } while (dwarf_siblingof(die_mem, die_mem) == 0);
-
-       return NULL;
+       return DIE_FIND_CB_CONTINUE;
 }
 
-/* Compare diename and tname */
-static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
+/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */
+static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
+                                     Dwarf_Die *die_mem)
 {
-       const char *name;
-       name = dwarf_diename(dw_die);
-       DIE_IF(name == NULL);
-       return strcmp(tname, name);
+       return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
 }
 
-/* Get entry pc(or low pc, 1st entry of ranges)  of the die */
-static Dwarf_Addr die_get_entrypc(Dwarf_Die *dw_die)
+static int __die_find_variable_cb(Dwarf_Die *die_mem, void *data)
 {
-       Dwarf_Addr epc;
-       int ret;
+       const char *name = data;
+       int tag;
 
-       ret = dwarf_entrypc(dw_die, &epc);
-       DIE_IF(ret == -1);
-       return epc;
+       tag = dwarf_tag(die_mem);
+       if ((tag == DW_TAG_formal_parameter ||
+            tag == DW_TAG_variable) &&
+           (die_compare_name(die_mem, name) == 0))
+               return DIE_FIND_CB_FOUND;
+
+       return DIE_FIND_CB_CONTINUE;
 }
 
-/* Get a variable die */
+/* Find a variable called 'name' */
 static Dwarf_Die *die_find_variable(Dwarf_Die *sp_die, const char *name,
                                    Dwarf_Die *die_mem)
 {
-       Dwarf_Die child_die;
-       int tag;
-       int ret;
-
-       ret = dwarf_child(sp_die, die_mem);
-       if (ret != 0)
-               return NULL;
-
-       do {
-               tag = dwarf_tag(die_mem);
-               if ((tag == DW_TAG_formal_parameter ||
-                    tag == DW_TAG_variable) &&
-                   (die_compare_name(die_mem, name) == 0))
-                       return die_mem;
-
-               if (die_find_variable(die_mem, name, &child_die)) {
-                       memcpy(die_mem, &child_die, sizeof(Dwarf_Die));
-                       return die_mem;
-               }
-       } while (dwarf_siblingof(die_mem, die_mem) == 0);
-
-       return NULL;
+       return die_find_child(sp_die, __die_find_variable_cb, (void *)name,
+                             die_mem);
 }
 
 /*