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      1 /* basic_blocks.c  -  Basic-block level related code: reading/writing
      2    of basic-block info to/from gmon.out; computing and formatting of
      3    basic-block related statistics.
      4 
      5    Copyright (C) 1999-2014 Free Software Foundation, Inc.
      6 
      7    This file is part of GNU Binutils.
      8 
      9    This program is free software; you can redistribute it and/or modify
     10    it under the terms of the GNU General Public License as published by
     11    the Free Software Foundation; either version 3 of the License, or
     12    (at your option) any later version.
     13 
     14    This program is distributed in the hope that it will be useful,
     15    but WITHOUT ANY WARRANTY; without even the implied warranty of
     16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     17    GNU General Public License for more details.
     18 
     19    You should have received a copy of the GNU General Public License
     20    along with this program; if not, write to the Free Software
     21    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
     22    02110-1301, USA.  */
     23 
     24 #include "gprof.h"
     26 #include "libiberty.h"
     27 #include "filenames.h"
     28 #include "basic_blocks.h"
     29 #include "corefile.h"
     30 #include "gmon_io.h"
     31 #include "gmon_out.h"
     32 #include "search_list.h"
     33 #include "source.h"
     34 #include "symtab.h"
     35 #include "sym_ids.h"
     36 
     37 static int cmp_bb (const PTR, const PTR);
     38 static int cmp_ncalls (const PTR, const PTR);
     39 static void fskip_string (FILE *);
     40 static void annotate_with_count (char *, unsigned int, int, PTR);
     41 
     42 /* Default option values:  */
     43 bfd_boolean bb_annotate_all_lines = FALSE;
     44 unsigned long bb_min_calls = 1;
     45 int bb_table_length = 10;
     46 
     47 /* Variables used to compute annotated source listing stats:  */
     48 static long num_executable_lines;
     49 static long num_lines_executed;
     50 
     51 
     52 /* Helper for sorting.  Compares two symbols and returns result
     53    such that sorting will be increasing according to filename, line
     54    number, and address (in that order).  */
     55 
     56 static int
     57 cmp_bb (const PTR lp, const PTR rp)
     58 {
     59   int r;
     60   const Sym *left = *(const Sym **) lp;
     61   const Sym *right = *(const Sym **) rp;
     62 
     63   if (left->file && right->file)
     64     {
     65       r = filename_cmp (left->file->name, right->file->name);
     66 
     67       if (r)
     68 	return r;
     69 
     70       if (left->line_num != right->line_num)
     71 	return left->line_num - right->line_num;
     72     }
     73 
     74   if (left->addr < right->addr)
     75     return -1;
     76   else if (left->addr > right->addr)
     77     return 1;
     78   else
     79     return 0;
     80 }
     81 
     82 
     83 /* Helper for sorting.  Order basic blocks in decreasing number of
     84    calls, ties are broken in increasing order of line numbers.  */
     85 static int
     86 cmp_ncalls (const PTR lp, const PTR rp)
     87 {
     88   const Sym *left = *(const Sym **) lp;
     89   const Sym *right = *(const Sym **) rp;
     90 
     91   if (!left)
     92     return 1;
     93   else if (!right)
     94     return -1;
     95 
     96   if (left->ncalls < right->ncalls)
     97     return 1;
     98   else if (left->ncalls > right->ncalls)
     99     return -1;
    100 
    101   return left->line_num - right->line_num;
    102 }
    103 
    104 /* Skip over variable length string.  */
    105 static void
    106 fskip_string (FILE *fp)
    107 {
    108   int ch;
    109 
    110   while ((ch = fgetc (fp)) != EOF)
    111     {
    112       if (ch == '\0')
    113 	break;
    114     }
    115 }
    116 
    117 /* Read a basic-block record from file IFP.  FILENAME is the name
    118    of file IFP and is provided for formatting error-messages only.  */
    119 
    120 void
    121 bb_read_rec (FILE *ifp, const char *filename)
    122 {
    123   unsigned int nblocks, b;
    124   bfd_vma addr, ncalls;
    125   Sym *sym;
    126 
    127   if (gmon_io_read_32 (ifp, &nblocks))
    128     {
    129       fprintf (stderr, _("%s: %s: unexpected end of file\n"),
    130 	       whoami, filename);
    131       done (1);
    132     }
    133 
    134   nblocks = bfd_get_32 (core_bfd, (bfd_byte *) & nblocks);
    135   if (gmon_file_version == 0)
    136     fskip_string (ifp);
    137 
    138   for (b = 0; b < nblocks; ++b)
    139     {
    140       if (gmon_file_version == 0)
    141 	{
    142 	  int line_num;
    143 
    144 	  /* Version 0 had lots of extra stuff that we don't
    145 	     care about anymore.  */
    146 	  if ((fread (&ncalls, sizeof (ncalls), 1, ifp) != 1)
    147 	      || (fread (&addr, sizeof (addr), 1, ifp) != 1)
    148 	      || (fskip_string (ifp), FALSE)
    149 	      || (fskip_string (ifp), FALSE)
    150 	      || (fread (&line_num, sizeof (line_num), 1, ifp) != 1))
    151 	    {
    152 	      perror (filename);
    153 	      done (1);
    154 	    }
    155 	}
    156       else if (gmon_io_read_vma (ifp, &addr)
    157 	       || gmon_io_read_vma (ifp, &ncalls))
    158 	{
    159 	  perror (filename);
    160 	  done (1);
    161 	}
    162 
    163       /* Basic-block execution counts are meaningful only if we're
    164 	 profiling at the line-by-line level:  */
    165       if (line_granularity)
    166 	{
    167 	  sym = sym_lookup (&symtab, addr);
    168 
    169 	  if (sym)
    170 	    {
    171 	      int i;
    172 
    173 	      DBG (BBDEBUG,
    174 		   printf ("[bb_read_rec] 0x%lx->0x%lx (%s:%d) cnt=%lu\n",
    175 			   (unsigned long) addr, (unsigned long) sym->addr,
    176 			   sym->name, sym->line_num, (unsigned long) ncalls));
    177 
    178 	      for (i = 0; i < NBBS; i++)
    179 		{
    180 		  if (! sym->bb_addr[i] || sym->bb_addr[i] == addr)
    181 		    {
    182 		      sym->bb_addr[i] = addr;
    183 		      sym->bb_calls[i] += ncalls;
    184 		      break;
    185 		    }
    186 		}
    187 	    }
    188 	}
    189       else
    190 	{
    191 	  static bfd_boolean user_warned = FALSE;
    192 
    193 	  if (!user_warned)
    194 	    {
    195 	      user_warned = TRUE;
    196 	      fprintf (stderr,
    197   _("%s: warning: ignoring basic-block exec counts (use -l or --line)\n"),
    198 		       whoami);
    199 	    }
    200 	}
    201     }
    202   return;
    203 }
    204 
    205 /* Write all basic-blocks with non-zero counts to file OFP.  FILENAME
    206    is the name of OFP and is provided for producing error-messages
    207    only.  */
    208 void
    209 bb_write_blocks (FILE *ofp, const char *filename)
    210 {
    211   unsigned int nblocks = 0;
    212   Sym *sym;
    213   int i;
    214 
    215   /* Count how many non-zero blocks with have:  */
    216   for (sym = symtab.base; sym < symtab.limit; ++sym)
    217     {
    218       for (i = 0; i < NBBS && sym->bb_addr[i]; i++)
    219 	;
    220       nblocks += i;
    221     }
    222 
    223   /* Write header:  */
    224   if (gmon_io_write_8 (ofp, GMON_TAG_BB_COUNT)
    225       || gmon_io_write_32 (ofp, nblocks))
    226     {
    227       perror (filename);
    228       done (1);
    229     }
    230 
    231   /* Write counts:  */
    232   for (sym = symtab.base; sym < symtab.limit; ++sym)
    233     {
    234       for (i = 0; i < NBBS && sym->bb_addr[i]; i++)
    235 	{
    236 	  if (gmon_io_write_vma (ofp, sym->bb_addr[i])
    237 	      || gmon_io_write_vma (ofp, (bfd_vma) sym->bb_calls[i]))
    238 	    {
    239 	      perror (filename);
    240 	      done (1);
    241 	    }
    242 	}
    243     }
    244 }
    245 
    246 /* Output basic-block statistics in a format that is easily parseable.
    247    Current the format is:
    248 
    249 	<filename>:<line-number>: (<function-name>:<bb-addr): <ncalls>  */
    250 
    251 void
    252 print_exec_counts ()
    253 {
    254   Sym **sorted_bbs, *sym;
    255   unsigned int i, j, len;
    256 
    257   if (first_output)
    258     first_output = FALSE;
    259   else
    260     printf ("\f\n");
    261 
    262   /* Sort basic-blocks according to function name and line number:  */
    263   sorted_bbs = (Sym **) xmalloc (symtab.len * sizeof (sorted_bbs[0]));
    264   len = 0;
    265 
    266   for (sym = symtab.base; sym < symtab.limit; ++sym)
    267     {
    268       /* Accept symbol if it's in the INCL_EXEC table
    269 	 or there is no INCL_EXEC table
    270 	 and it does not appear in the EXCL_EXEC table.  */
    271       if (sym_lookup (&syms[INCL_EXEC], sym->addr)
    272 	  || (syms[INCL_EXEC].len == 0
    273 	      && !sym_lookup (&syms[EXCL_EXEC], sym->addr)))
    274 	{
    275 	  sorted_bbs[len++] = sym;
    276 	}
    277     }
    278 
    279   qsort (sorted_bbs, len, sizeof (sorted_bbs[0]), cmp_bb);
    280 
    281   /* Output basic-blocks:  */
    282 
    283   for (i = 0; i < len; ++i)
    284     {
    285       sym = sorted_bbs [i];
    286 
    287       if (sym->ncalls > 0 || ! ignore_zeros)
    288 	{
    289 	  /* FIXME: This only works if bfd_vma is unsigned long.  */
    290 	  printf (_("%s:%d: (%s:0x%lx) %lu executions\n"),
    291 		  sym->file ? sym->file->name : _("<unknown>"), sym->line_num,
    292 		  sym->name, (unsigned long) sym->addr, sym->ncalls);
    293 	}
    294 
    295       for (j = 0; j < NBBS && sym->bb_addr[j]; j ++)
    296 	{
    297 	  if (sym->bb_calls[j] > 0 || ! ignore_zeros)
    298 	    {
    299 	      /* FIXME: This only works if bfd_vma is unsigned long.  */
    300 	      printf (_("%s:%d: (%s:0x%lx) %lu executions\n"),
    301 		      sym->file ? sym->file->name : _("<unknown>"), sym->line_num,
    302 		      sym->name, (unsigned long) sym->bb_addr[j],
    303 		      sym->bb_calls[j]);
    304 	    }
    305 	}
    306     }
    307   free (sorted_bbs);
    308 }
    309 
    310 /* Helper for bb_annotated_source: format annotation containing
    311    number of line executions.  Depends on being called on each
    312    line of a file in sequential order.
    313 
    314    Global variable bb_annotate_all_lines enables execution count
    315    compression (counts are supressed if identical to the last one)
    316    and prints counts on all executed lines.  Otherwise, print
    317    all basic-block execution counts exactly once on the line
    318    that starts the basic-block.  */
    319 
    320 static void
    321 annotate_with_count (char *buf, unsigned int width, int line_num, PTR arg)
    322 {
    323   Source_File *sf = (Source_File *) arg;
    324   Sym *b;
    325   unsigned int i;
    326   static unsigned long last_count;
    327   unsigned long last_print = (unsigned long) -1;
    328 
    329   b = NULL;
    330 
    331   if (line_num <= sf->num_lines)
    332     b = (Sym *) sf->line[line_num - 1];
    333 
    334   if (!b)
    335     {
    336       for (i = 0; i < width; i++)
    337 	buf[i] = ' ';
    338       buf[width] = '\0';
    339     }
    340   else
    341     {
    342       char tmpbuf[NBBS * 30];
    343       char *p;
    344       unsigned long ncalls;
    345       int ncalls_set;
    346       unsigned int len;
    347 
    348       ++num_executable_lines;
    349 
    350       p = tmpbuf;
    351       *p = '\0';
    352 
    353       ncalls = 0;
    354       ncalls_set = 0;
    355 
    356       /* If this is a function entry point, label the line no matter what.
    357 	 Otherwise, we're in the middle of a function, so check to see
    358 	 if the first basic-block address is larger than the starting
    359 	 address of the line.  If so, then this line begins with a
    360 	 a portion of the previous basic-block, so print that prior
    361 	 execution count (if bb_annotate_all_lines is set).  */
    362       if (b->is_func)
    363 	{
    364 	  sprintf (p, "%lu", b->ncalls);
    365 	  p += strlen (p);
    366 	  last_count = b->ncalls;
    367 	  last_print = last_count;
    368 	  ncalls = b->ncalls;
    369 	  ncalls_set = 1;
    370 	}
    371       else if (bb_annotate_all_lines
    372 	       && b->bb_addr[0] && b->bb_addr[0] > b->addr)
    373 	{
    374 	  sprintf (p, "%lu", last_count);
    375 	  p += strlen (p);
    376 	  last_print = last_count;
    377 	  ncalls = last_count;
    378 	  ncalls_set = 1;
    379 	}
    380 
    381       /* Loop through all of this line's basic-blocks.  For each one,
    382 	 update last_count, then compress sequential identical counts
    383 	 (if bb_annotate_all_lines) and print the execution count.  */
    384 
    385       for (i = 0; i < NBBS && b->bb_addr[i]; i++)
    386 	{
    387 	  last_count = b->bb_calls[i];
    388 	  if (! ncalls_set)
    389 	    {
    390 	      ncalls = 0;
    391 	      ncalls_set = 1;
    392 	    }
    393 	  ncalls += last_count;
    394 
    395 	  if (bb_annotate_all_lines && last_count == last_print)
    396 	    continue;
    397 
    398 	  if (p > tmpbuf)
    399 	    *p++ = ',';
    400 	  sprintf (p, "%lu", last_count);
    401 	  p += strlen (p);
    402 
    403 	  last_print = last_count;
    404 	}
    405 
    406       /* We're done.  If nothing has been printed on this line,
    407 	 print the last execution count (bb_annotate_all_lines),
    408 	 which could be from either a previous line (if there were
    409 	 no BBs on this line), or from this line (if all our BB
    410 	 counts were compressed out because they were identical).  */
    411 
    412       if (bb_annotate_all_lines && p == tmpbuf)
    413 	{
    414 	  sprintf (p, "%lu", last_count);
    415 	  p += strlen (p);
    416 	  ncalls = last_count;
    417 	  ncalls_set = 1;
    418 	}
    419 
    420       if (! ncalls_set)
    421 	{
    422 	  unsigned int c;
    423 
    424 	  for (c = 0; c < width; c++)
    425 	    buf[c] = ' ';
    426 	  buf[width] = '\0';
    427 	  return;
    428 	}
    429 
    430       ++num_lines_executed;
    431 
    432       if (ncalls < bb_min_calls)
    433 	{
    434 	  strcpy (tmpbuf, "#####");
    435 	  p = tmpbuf + 5;
    436 	}
    437 
    438       strcpy (p, " -> ");
    439       p += 4;
    440 
    441       len = p - tmpbuf;
    442       if (len >= width)
    443 	{
    444 	  strncpy (buf, tmpbuf, width);
    445 	  buf[width] = '\0';
    446 	}
    447       else
    448 	{
    449 	  unsigned int c;
    450 
    451 	  strcpy (buf + width - len, tmpbuf);
    452 	  for (c = 0; c < width - len; ++c)
    453 	    buf[c] = ' ';
    454 	}
    455     }
    456 }
    457 
    458 /* Annotate the files named in SOURCE_FILES with basic-block statistics
    459    (execution counts).  After each source files, a few statistics
    460    regarding that source file are printed.  */
    461 
    462 void
    463 print_annotated_source ()
    464 {
    465   Sym *sym, *line_stats, *new_line;
    466   Source_File *sf;
    467   int i, table_len;
    468   FILE *ofp;
    469 
    470   /* Find maximum line number for each source file that user is
    471      interested in:  */
    472   for (sym = symtab.base; sym < symtab.limit; ++sym)
    473     {
    474       /* Accept symbol if it's file is known, its line number is
    475 	 bigger than anything we have seen for that file so far and
    476 	 if it's in the INCL_ANNO table or there is no INCL_ANNO
    477 	 table and it does not appear in the EXCL_ANNO table.  */
    478       if (sym->file && sym->line_num > sym->file->num_lines
    479 	  && (sym_lookup (&syms[INCL_ANNO], sym->addr)
    480 	      || (syms[INCL_ANNO].len == 0
    481 		  && !sym_lookup (&syms[EXCL_ANNO], sym->addr))))
    482 	{
    483 	  sym->file->num_lines = sym->line_num;
    484 	}
    485     }
    486 
    487   /* Allocate line descriptors:  */
    488   for (sf = first_src_file; sf; sf = sf->next)
    489     {
    490       if (sf->num_lines > 0)
    491 	{
    492 	  sf->line = (void **) xmalloc (sf->num_lines * sizeof (sf->line[0]));
    493 	  memset (sf->line, 0, sf->num_lines * sizeof (sf->line[0]));
    494 	}
    495     }
    496 
    497   /* Count executions per line:  */
    498   for (sym = symtab.base; sym < symtab.limit; ++sym)
    499     {
    500       if (sym->file && sym->file->num_lines
    501 	  && (sym_lookup (&syms[INCL_ANNO], sym->addr)
    502 	      || (syms[INCL_ANNO].len == 0
    503 		  && !sym_lookup (&syms[EXCL_ANNO], sym->addr))))
    504 	{
    505 	  sym->file->ncalls += sym->ncalls;
    506 	  line_stats = (Sym *) sym->file->line[sym->line_num - 1];
    507 
    508 	  if (!line_stats)
    509 	    {
    510 	      /* Common case has at most one basic-block per source line:  */
    511 	      sym->file->line[sym->line_num - 1] = sym;
    512 	    }
    513 	  else if (!line_stats->addr)
    514 	    {
    515 	      /* sym is the 3rd .. nth basic block for this line:  */
    516 	      line_stats->ncalls += sym->ncalls;
    517 	    }
    518 	  else
    519 	    {
    520 	      /* sym is the second basic block for this line.  */
    521 	      new_line = (Sym *) xmalloc (sizeof (*new_line));
    522 	      *new_line = *line_stats;
    523 	      new_line->addr = 0;
    524 	      new_line->ncalls += sym->ncalls;
    525 	      sym->file->line[sym->line_num - 1] = new_line;
    526 	    }
    527 	}
    528     }
    529 
    530   /* Plod over source files, annotating them:  */
    531   for (sf = first_src_file; sf; sf = sf->next)
    532     {
    533       if (!sf->num_lines || (ignore_zeros && sf->ncalls == 0))
    534 	continue;
    535 
    536       num_executable_lines = num_lines_executed = 0;
    537 
    538       ofp = annotate_source (sf, 16, annotate_with_count, sf);
    539       if (!ofp)
    540 	continue;
    541 
    542       if (bb_table_length > 0)
    543 	{
    544 	  fprintf (ofp, _("\n\nTop %d Lines:\n\n     Line      Count\n\n"),
    545 		   bb_table_length);
    546 
    547 	  /* Abuse line arrays---it's not needed anymore:  */
    548 	  qsort (sf->line, sf->num_lines, sizeof (sf->line[0]), cmp_ncalls);
    549 	  table_len = bb_table_length;
    550 
    551 	  if (table_len > sf->num_lines)
    552 	    table_len = sf->num_lines;
    553 
    554 	  for (i = 0; i < table_len; ++i)
    555 	    {
    556 	      sym = (Sym *) sf->line[i];
    557 
    558 	      if (!sym || sym->ncalls == 0)
    559 		  break;
    560 
    561 	      fprintf (ofp, "%9d %10lu\n", sym->line_num, sym->ncalls);
    562 	    }
    563 	}
    564 
    565       free (sf->line);
    566       sf->line = 0;
    567 
    568       fprintf (ofp, _("\nExecution Summary:\n\n"));
    569       fprintf (ofp, _("%9ld   Executable lines in this file\n"),
    570 	       num_executable_lines);
    571       fprintf (ofp, _("%9ld   Lines executed\n"), num_lines_executed);
    572       fprintf (ofp, _("%9.2f   Percent of the file executed\n"),
    573 	       num_executable_lines
    574 	       ? 100.0 * num_lines_executed / (double) num_executable_lines
    575 	       : 100.0);
    576       fprintf (ofp, _("\n%9lu   Total number of line executions\n"),
    577 	       sf->ncalls);
    578       fprintf (ofp, _("%9.2f   Average executions per line\n"),
    579 	       num_executable_lines
    580 	       ? (double) sf->ncalls / (double) num_executable_lines
    581 	       : 0.0);
    582 
    583       if (ofp != stdout)
    584 	fclose (ofp);
    585     }
    586 }
    587