1 files changed, 70 insertions, 26 deletions

diff --git a/libdw/dwarf_getfuncs.c b/libdw/dwarf_getfuncs.c
index afc5b6eb..87e0341a 100644
--- a/libdw/dwarf_getfuncs.c
+++ b/libdw/dwarf_getfuncs.c
@@ -1,5 +1,5 @@
 /* Get function information.
-   Copyright (C) 2005 Red Hat, Inc.
+   Copyright (C) 2005, 2013 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2005.
 
@@ -35,6 +35,63 @@
 #include "libdwP.h"
 
 
+struct visitor_info
+{
+  /* The user callback of dwarf_getfuncs.  */
+  int (*callback) (Dwarf_Die *, void *);
+
+  /* The user arg value to dwarf_getfuncs.  */
+  void *arg;
+
+  /* The DIE offset where to (re)start the search.  Zero for all.  */
+  Dwarf_Off start_offset;
+
+  /* Last subprogram DIE offset seen.  */
+  Dwarf_Off last_offset;
+
+  /* The CU only contains C functions.  Allows pruning of most subtrees.  */
+  bool c_cu;
+};
+
+static int
+tree_visitor (unsigned int depth __attribute__ ((unused)),
+	      struct Dwarf_Die_Chain *chain, void *arg)
+{
+  struct visitor_info *const v = arg;
+  Dwarf_Die *die = &chain->die;
+  Dwarf_Off start_offset = v->start_offset;
+  Dwarf_Off die_offset = INTUSE(dwarf_dieoffset) (die);
+
+  /* Pure C CUs can only contain defining subprogram DIEs as direct
+     children of the CU DIE or as nested function inside a normal C
+     code constructs.  */
+  int tag = INTUSE(dwarf_tag) (die);
+  if (v->c_cu
+      && tag != DW_TAG_subprogram
+      && tag != DW_TAG_lexical_block
+      && tag != DW_TAG_inlined_subroutine)
+    {
+      chain->prune = true;
+      return DWARF_CB_OK;
+    }
+
+  /* Skip all DIEs till we found the (re)start offset.  */
+  if (start_offset != 0)
+    {
+      if (die_offset == start_offset)
+	v->start_offset = 0;
+      return DWARF_CB_OK;
+    }
+
+  /* If this isn't a (defining) subprogram entity, skip DIE.  */
+  if (tag != DW_TAG_subprogram
+      || INTUSE(dwarf_hasattr) (die, DW_AT_declaration))
+    return DWARF_CB_OK;
+
+  v->last_offset = die_offset;
+  return (*v->callback) (die, v->arg);
+}
+
 ptrdiff_t
 dwarf_getfuncs (Dwarf_Die *cudie, int (*callback) (Dwarf_Die *, void *),
 		void *arg, ptrdiff_t offset)
@@ -43,31 +100,18 @@ dwarf_getfuncs (Dwarf_Die *cudie, int (*callback) (Dwarf_Die *, void *),
 		|| INTUSE(dwarf_tag) (cudie) != DW_TAG_compile_unit))
     return -1;
 
-  Dwarf_Die die_mem;
-  Dwarf_Die *die;
+  int lang = INTUSE(dwarf_srclang) (cudie);
+  bool c_cu = (lang == DW_LANG_C89
+	       || lang == DW_LANG_C
+	       || lang == DW_LANG_C99);
 
-  int res;
-  if (offset == 0)
-    res = INTUSE(dwarf_child) (cudie, &die_mem);
-  else
-    {
-      die = INTUSE(dwarf_offdie) (cudie->cu->dbg, offset, &die_mem);
-      res = INTUSE(dwarf_siblingof) (die, &die_mem);
-    }
-  die = res != 0 ? NULL : &die_mem;
+  struct visitor_info v = { callback, arg, offset, 0, c_cu };
+  struct Dwarf_Die_Chain chain = { .die = CUDIE (cudie->cu),
+				   .parent = NULL };
+  int res = __libdw_visit_scopes (0, &chain, &tree_visitor, NULL, &v);
 
-  while (die != NULL)
-    {
-      if (INTUSE(dwarf_tag) (die) == DW_TAG_subprogram)
-	{
-	  if (callback (die, arg) != DWARF_CB_OK)
-	    return INTUSE(dwarf_dieoffset) (die);
-	}
-
-      if (INTUSE(dwarf_siblingof) (die, &die_mem) != 0)
-	break;
-    }
-
-  /* That's all.  */
-  return 0;
+  if (res == DWARF_CB_ABORT)
+    return v.last_offset;
+  else
+    return res;
 }