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       1                 :             : /* Get function information.
       2                 :             :    Copyright (C) 2005, 2013, 2015 Red Hat, Inc.
       3                 :             :    Copyright (C) 2024, 2025 Mark J. Wielaard <mark@klomp.org>
       4                 :             :    This file is part of elfutils.
       5                 :             :    Written by Ulrich Drepper <drepper@redhat.com>, 2005.
       6                 :             : 
       7                 :             :    This file is free software; you can redistribute it and/or modify
       8                 :             :    it under the terms of either
       9                 :             : 
      10                 :             :      * the GNU Lesser General Public License as published by the Free
      11                 :             :        Software Foundation; either version 3 of the License, or (at
      12                 :             :        your option) any later version
      13                 :             : 
      14                 :             :    or
      15                 :             : 
      16                 :             :      * the GNU General Public License as published by the Free
      17                 :             :        Software Foundation; either version 2 of the License, or (at
      18                 :             :        your option) any later version
      19                 :             : 
      20                 :             :    or both in parallel, as here.
      21                 :             : 
      22                 :             :    elfutils is distributed in the hope that it will be useful, but
      23                 :             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      24                 :             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      25                 :             :    General Public License for more details.
      26                 :             : 
      27                 :             :    You should have received copies of the GNU General Public License and
      28                 :             :    the GNU Lesser General Public License along with this program.  If
      29                 :             :    not, see <http://www.gnu.org/licenses/>.  */
      30                 :             : 
      31                 :             : #ifdef HAVE_CONFIG_H
      32                 :             : # include <config.h>
      33                 :             : #endif
      34                 :             : 
      35                 :             : #include <dwarf.h>
      36                 :             : #include "libdwP.h"
      37                 :             : 
      38                 :             : 
      39                 :             : struct visitor_info
      40                 :             : {
      41                 :             :   /* The user callback of dwarf_getfuncs.  */
      42                 :             :   int (*callback) (Dwarf_Die *, void *);
      43                 :             : 
      44                 :             :   /* The user arg value to dwarf_getfuncs.  */
      45                 :             :   void *arg;
      46                 :             : 
      47                 :             :   /* Addr of the DIE offset where to (re)start the search.  Zero for all.  */
      48                 :             :   void *start_addr;
      49                 :             : 
      50                 :             :   /* Last subprogram DIE addr seen.  */
      51                 :             :   void *last_addr;
      52                 :             : 
      53                 :             :   /* The CU only contains C functions.  Allows pruning of most subtrees.  */
      54                 :             :   bool c_cu;
      55                 :             : };
      56                 :             : 
      57                 :             : static int
      58                 :     2640530 : tree_visitor (unsigned int depth __attribute__ ((unused)),
      59                 :             :               struct Dwarf_Die_Chain *chain, void *arg)
      60                 :             : {
      61                 :     2640530 :   struct visitor_info *const v = arg;
      62                 :     2640530 :   Dwarf_Die *die = &chain->die;
      63                 :     2640530 :   void *start_addr = v->start_addr;
      64                 :     2640530 :   void *die_addr = die->addr;
      65                 :             : 
      66                 :             :   /* Pure C CUs can only contain defining subprogram DIEs as direct
      67                 :             :      children of the CU DIE or as nested function inside a normal C
      68                 :             :      code constructs.  */
      69                 :     2640530 :   int tag = INTUSE(dwarf_tag) (die);
      70         [ +  + ]:     2640530 :   if (v->c_cu
      71                 :     2621532 :       && tag != DW_TAG_subprogram
      72         [ +  + ]:     2621532 :       && tag != DW_TAG_lexical_block
      73         [ +  + ]:     2408004 :       && tag != DW_TAG_inlined_subroutine)
      74                 :             :     {
      75                 :     2342018 :       chain->prune = true;
      76                 :     2342018 :       return DWARF_CB_OK;
      77                 :             :     }
      78                 :             : 
      79                 :             :   /* Skip all DIEs till we found the (re)start addr.  */
      80         [ +  + ]:      298512 :   if (start_addr != NULL)
      81                 :             :     {
      82         [ +  + ]:         232 :       if (die_addr == start_addr)
      83                 :          82 :         v->start_addr = NULL;
      84                 :         232 :       return DWARF_CB_OK;
      85                 :             :     }
      86                 :             : 
      87                 :             :   /* If this isn't a (defining) subprogram entity, skip DIE.  */
      88         [ +  + ]:      298280 :   if (tag != DW_TAG_subprogram
      89         [ +  + ]:      131042 :       || INTUSE(dwarf_hasattr) (die, DW_AT_declaration))
      90                 :      235874 :     return DWARF_CB_OK;
      91                 :             : 
      92                 :       62406 :   v->last_addr = die_addr;
      93                 :       62406 :   return (*v->callback) (die, v->arg);
      94                 :             : }
      95                 :             : 
      96                 :             : ptrdiff_t
      97                 :       15598 : dwarf_getfuncs (Dwarf_Die *cudie, int (*callback) (Dwarf_Die *, void *),
      98                 :             :                 void *arg, ptrdiff_t offset)
      99                 :             : {
     100   [ +  -  +  + ]:       15598 :   if (unlikely (cudie == NULL
     101                 :             :                 || INTUSE(dwarf_tag) (cudie) != DW_TAG_compile_unit))
     102                 :           4 :     return -1;
     103                 :             : 
     104                 :       15594 :   Dwarf_Word lang;
     105                 :       15594 :   bool c_cu = (INTUSE(dwarf_language) (cudie, &lang, NULL) == 0
     106   [ +  +  +  + ]:       15594 :                && lang == DW_LNAME_C);
     107                 :             : 
     108                 :       15594 :   struct visitor_info v = { callback, arg, (void *) offset, NULL, c_cu };
     109                 :       15594 :   struct Dwarf_Die_Chain chain = { .die = CUDIE (cudie->cu),
     110                 :             :                                    .parent = NULL };
     111                 :       15594 :   int res = __libdw_visit_scopes (0, &chain, NULL, &tree_visitor, NULL, &v);
     112                 :             : 
     113         [ +  + ]:       15594 :   if (res == DWARF_CB_ABORT)
     114                 :          82 :     return (ptrdiff_t) v.last_addr;
     115                 :             :   else
     116                 :       15512 :     return res;
     117                 :             : }