1 /* call_graph.c  -  Create call graphs.
2 
3    Copyright (C) 1999-2020 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 
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 }
131