gprof/call_graph.c

   1 /* call_graph.c  -  Create call graphs.
   2
   3    Copyright (C) 1999-2021 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Binutils.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
  20    02110-1301, USA.  */
  21 \f
  22 #include "gprof.h"
  23 #include "search_list.h"
  24 #include "source.h"
  25 #include "symtab.h"
  26 #include "cg_arcs.h"
  27 #include "call_graph.h"
  28 #include "corefile.h"
  29 #include "gmon_io.h"
  30 #include "gmon_out.h"
  31 #include "sym_ids.h"
  32
  33 void
  34 cg_tally (bfd_vma from_pc, bfd_vma self_pc, unsigned long count)
  35 {
  36   Sym *parent;
  37   Sym *child;
  38
  39   parent = sym_lookup (&symtab, from_pc);
  40   child = sym_lookup (&symtab, self_pc);
  41
  42   if (child == NULL || parent == NULL)
  43     return;
  44
  45   /* If we're doing line-by-line profiling, both the parent and the
  46      child will probably point to line symbols instead of function
  47      symbols.  For the parent this is fine, since this identifies the
  48      line number in the calling routing, but the child should always
  49      point to a function entry point, so we back up in the symbol
  50      table until we find it.
  51
  52      For normal profiling, is_func will be set on all symbols, so this
  53      code will do nothing.  */
  54   while (child >= symtab.base && ! child->is_func)
  55     --child;
  56
  57   if (child < symtab.base)
  58     return;
  59
  60   /* Keep arc if it is on INCL_ARCS table or if the INCL_ARCS table
  61      is empty and it is not in the EXCL_ARCS table.  */
  62   if (sym_id_arc_is_present (&syms[INCL_ARCS], parent, child)
  63       || (syms[INCL_ARCS].len == 0
  64           && !sym_id_arc_is_present (&syms[EXCL_ARCS], parent, child)))
  65     {
  66       child->ncalls += count;
  67       DBG (TALLYDEBUG,
  68            printf (_("[cg_tally] arc from %s to %s traversed %lu times\n"),
  69                    parent->name, child->name, count));
  70       arc_add (parent, child, count);
  71     }
  72 }
  73
  74 /* Read a record from file IFP describing an arc in the function
  75    call-graph and the count of how many times the arc has been
  76    traversed.  FILENAME is the name of file IFP and is provided
  77    for formatting error-messages only.  */
  78
  79 void
  80 cg_read_rec (FILE *ifp, const char *filename)
  81 {
  82   bfd_vma from_pc, self_pc;
  83   unsigned int count;
  84
  85   if (gmon_io_read_vma (ifp, &from_pc)
  86       || gmon_io_read_vma (ifp, &self_pc)
  87       || gmon_io_read_32 (ifp, &count))
  88     {
  89       fprintf (stderr, _("%s: %s: unexpected end of file\n"),
  90                whoami, filename);
  91       done (1);
  92     }
  93
  94   DBG (SAMPLEDEBUG,
  95        printf ("[cg_read_rec] frompc 0x%lx selfpc 0x%lx count %lu\n",
  96                (unsigned long) from_pc, (unsigned long) self_pc,
  97                (unsigned long) count));
  98   /* Add this arc:  */
  99   cg_tally (from_pc, self_pc, count);
 100 }
 101
 102 /* Write all the arcs in the call-graph to file OFP.  FILENAME is
 103    the name of OFP and is provided for formatting error-messages
 104    only.  */
 105
 106 void
 107 cg_write_arcs (FILE *ofp, const char *filename)
 108 {
 109   Arc *arc;
 110   Sym *sym;
 111
 112   for (sym = symtab.base; sym < symtab.limit; sym++)
 113     {
 114       for (arc = sym->cg.children; arc; arc = arc->next_child)
 115         {
 116           if (gmon_io_write_8 (ofp, GMON_TAG_CG_ARC)
 117               || gmon_io_write_vma (ofp, arc->parent->addr)
 118               || gmon_io_write_vma (ofp, arc->child->addr)
 119               || gmon_io_write_32 (ofp, arc->count))
 120             {
 121               perror (filename);
 122               done (1);
 123             }
 124           DBG (SAMPLEDEBUG,
 125              printf ("[cg_write_arcs] frompc 0x%lx selfpc 0x%lx count %lu\n",
 126                      (unsigned long) arc->parent->addr,
 127                      (unsigned long) arc->child->addr, arc->count));
 128         }
 129     }
 130 }