gprof/basic_blocks.c

   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) 1999-2024 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 \f
  24 #include "gprof.h"
  25 #include "libiberty.h"
  26 #include "filenames.h"
  27 #include "basic_blocks.h"
  28 #include "corefile.h"
  29 #include "gmon_io.h"
  30 #include "gmon_out.h"
  31 #include "search_list.h"
  32 #include "source.h"
  33 #include "symtab.h"
  34 #include "sym_ids.h"
  35
  36 static int cmp_bb (const void *, const void *);
  37 static int cmp_ncalls (const void *, const void *);
  38 static void fskip_string (FILE *);
  39 static void annotate_with_count (char *, unsigned int, int, void *);
  40
  41 /* Default option values:  */
  42 bool bb_annotate_all_lines = false;
  43 unsigned long bb_min_calls = 1;
  44 int bb_table_length = 10;
  45
  46 /* Variables used to compute annotated source listing stats:  */
  47 static long num_executable_lines;
  48 static long num_lines_executed;
  49
  50
  51 /* Helper for sorting.  Compares two symbols and returns result
  52    such that sorting will be increasing according to filename, line
  53    number, and address (in that order).  */
  54
  55 static int
  56 cmp_bb (const void *lp, const void *rp)
  57 {
  58   int r;
  59   const Sym *left = *(const Sym **) lp;
  60   const Sym *right = *(const Sym **) rp;
  61
  62   if (left->file && right->file)
  63     {
  64       r = filename_cmp (left->file->name, right->file->name);
  65
  66       if (r)
  67         return r;
  68
  69       if (left->line_num != right->line_num)
  70         return left->line_num - right->line_num;
  71     }
  72
  73   if (left->addr < right->addr)
  74     return -1;
  75   else if (left->addr > right->addr)
  76     return 1;
  77   else
  78     return 0;
  79 }
  80
  81
  82 /* Helper for sorting.  Order basic blocks in decreasing number of
  83    calls, ties are broken in increasing order of line numbers.  */
  84 static int
  85 cmp_ncalls (const void *lp, const void *rp)
  86 {
  87   const Sym *left = *(const Sym **) lp;
  88   const Sym *right = *(const Sym **) rp;
  89
  90   if (!left)
  91     return 1;
  92   else if (!right)
  93     return -1;
  94
  95   if (left->ncalls < right->ncalls)
  96     return 1;
  97   else if (left->ncalls > right->ncalls)
  98     return -1;
  99
 100   return left->line_num - right->line_num;
 101 }
 102
 103 /* Skip over variable length string.  */
 104 static void
 105 fskip_string (FILE *fp)
 106 {
 107   int ch;
 108
 109   while ((ch = fgetc (fp)) != EOF)
 110     {
 111       if (ch == '\0')
 112         break;
 113     }
 114 }
 115
 116 /* Read a basic-block record from file IFP.  FILENAME is the name
 117    of file IFP and is provided for formatting error-messages only.  */
 118
 119 void
 120 bb_read_rec (FILE *ifp, const char *filename)
 121 {
 122   unsigned int nblocks, b;
 123   bfd_vma addr, ncalls;
 124   Sym *sym;
 125
 126   if (gmon_io_read_32 (ifp, &nblocks))
 127     {
 128       fprintf (stderr, _("%s: %s: unexpected end of file\n"),
 129                whoami, filename);
 130       done (1);
 131     }
 132
 133   nblocks = bfd_get_32 (core_bfd, (bfd_byte *) & nblocks);
 134   if (gmon_file_version == 0)
 135     fskip_string (ifp);
 136
 137   for (b = 0; b < nblocks; ++b)
 138     {
 139       if (gmon_file_version == 0)
 140         {
 141           int line_num;
 142
 143           /* Version 0 had lots of extra stuff that we don't
 144              care about anymore.  */
 145           if ((fread (&ncalls, sizeof (ncalls), 1, ifp) != 1)
 146               || (fread (&addr, sizeof (addr), 1, ifp) != 1)
 147               || (fskip_string (ifp), false)
 148               || (fskip_string (ifp), false)
 149               || (fread (&line_num, sizeof (line_num), 1, ifp) != 1))
 150             {
 151               perror (filename);
 152               done (1);
 153             }
 154         }
 155       else if (gmon_io_read_vma (ifp, &addr)
 156                || gmon_io_read_vma (ifp, &ncalls))
 157         {
 158           perror (filename);
 159           done (1);
 160         }
 161
 162       /* Basic-block execution counts are meaningful only if we're
 163          profiling at the line-by-line level:  */
 164       if (line_granularity)
 165         {
 166           sym = sym_lookup (&symtab, addr);
 167
 168           if (sym)
 169             {
 170               int i;
 171
 172               DBG (BBDEBUG,
 173                    printf ("[bb_read_rec] 0x%lx->0x%lx (%s:%d) cnt=%lu\n",
 174                            (unsigned long) addr, (unsigned long) sym->addr,
 175                            sym->name, sym->line_num, (unsigned long) ncalls));
 176
 177               for (i = 0; i < NBBS; i++)
 178                 {
 179                   if (! sym->bb_addr[i] || sym->bb_addr[i] == addr)
 180                     {
 181                       sym->bb_addr[i] = addr;
 182                       sym->bb_calls[i] += ncalls;
 183                       break;
 184                     }
 185                 }
 186             }
 187         }
 188       else
 189         {
 190           static bool user_warned = false;
 191
 192           if (!user_warned)
 193             {
 194               user_warned = true;
 195               fprintf (stderr,
 196   _("%s: warning: ignoring basic-block exec counts (use -l or --line)\n"),
 197                        whoami);
 198             }
 199         }
 200     }
 201   return;
 202 }
 203
 204 /* Write all basic-blocks with non-zero counts to file OFP.  FILENAME
 205    is the name of OFP and is provided for producing error-messages
 206    only.  */
 207 void
 208 bb_write_blocks (FILE *ofp, const char *filename)
 209 {
 210   unsigned int nblocks = 0;
 211   Sym *sym;
 212   int i;
 213
 214   /* Count how many non-zero blocks with have:  */
 215   for (sym = symtab.base; sym < symtab.limit; ++sym)
 216     {
 217       for (i = 0; i < NBBS && sym->bb_addr[i]; i++)
 218         ;
 219       nblocks += i;
 220     }
 221
 222   /* Write header:  */
 223   if (gmon_io_write_8 (ofp, GMON_TAG_BB_COUNT)
 224       || gmon_io_write_32 (ofp, nblocks))
 225     {
 226       perror (filename);
 227       done (1);
 228     }
 229
 230   /* Write counts:  */
 231   for (sym = symtab.base; sym < symtab.limit; ++sym)
 232     {
 233       for (i = 0; i < NBBS && sym->bb_addr[i]; i++)
 234         {
 235           if (gmon_io_write_vma (ofp, sym->bb_addr[i])
 236               || gmon_io_write_vma (ofp, (bfd_vma) sym->bb_calls[i]))
 237             {
 238               perror (filename);
 239               done (1);
 240             }
 241         }
 242     }
 243 }
 244
 245 /* Output basic-block statistics in a format that is easily parseable.
 246    Current the format is:
 247
 248         <filename>:<line-number>: (<function-name>:<bb-addr): <ncalls>  */
 249
 250 void
 251 print_exec_counts (void)
 252 {
 253   Sym **sorted_bbs, *sym;
 254   unsigned int i, j, len;
 255
 256   if (first_output)
 257     first_output = false;
 258   else
 259     printf ("\f\n");
 260
 261   /* Sort basic-blocks according to function name and line number:  */
 262   sorted_bbs = (Sym **) xmalloc (symtab.len * sizeof (sorted_bbs[0]));
 263   len = 0;
 264
 265   for (sym = symtab.base; sym < symtab.limit; ++sym)
 266     {
 267       /* Accept symbol if it's in the INCL_EXEC table
 268          or there is no INCL_EXEC table
 269          and it does not appear in the EXCL_EXEC table.  */
 270       if (sym_lookup (&syms[INCL_EXEC], sym->addr)
 271           || (syms[INCL_EXEC].len == 0
 272               && !sym_lookup (&syms[EXCL_EXEC], sym->addr)))
 273         {
 274           sorted_bbs[len++] = sym;
 275         }
 276     }
 277
 278   qsort (sorted_bbs, len, sizeof (sorted_bbs[0]), cmp_bb);
 279
 280   /* Output basic-blocks:  */
 281
 282   for (i = 0; i < len; ++i)
 283     {
 284       sym = sorted_bbs [i];
 285
 286       if (sym->ncalls > 0 || ! ignore_zeros)
 287         {
 288           /* FIXME: This only works if bfd_vma is unsigned long.  */
 289           printf (_("%s:%d: (%s:0x%lx) %lu executions\n"),
 290                   sym->file ? sym->file->name : _("<unknown>"), sym->line_num,
 291                   sym->name, (unsigned long) sym->addr, sym->ncalls);
 292         }
 293
 294       for (j = 0; j < NBBS && sym->bb_addr[j]; j ++)
 295         {
 296           if (sym->bb_calls[j] > 0 || ! ignore_zeros)
 297             {
 298               /* FIXME: This only works if bfd_vma is unsigned long.  */
 299               printf (_("%s:%d: (%s:0x%lx) %lu executions\n"),
 300                       sym->file ? sym->file->name : _("<unknown>"), sym->line_num,
 301                       sym->name, (unsigned long) sym->bb_addr[j],
 302                       sym->bb_calls[j]);
 303             }
 304         }
 305     }
 306   free (sorted_bbs);
 307 }
 308
 309 /* Helper for bb_annotated_source: format annotation containing
 310    number of line executions.  Depends on being called on each
 311    line of a file in sequential order.
 312
 313    Global variable bb_annotate_all_lines enables execution count
 314    compression (counts are suppressed if identical to the last one)
 315    and prints counts on all executed lines.  Otherwise, print
 316    all basic-block execution counts exactly once on the line
 317    that starts the basic-block.  */
 318
 319 static void
 320 annotate_with_count (char *buf, unsigned int width, int line_num, void *arg)
 321 {
 322   Source_File *sf = (Source_File *) arg;
 323   Sym *b;
 324   unsigned int i;
 325   static unsigned long last_count;
 326   unsigned long last_print = (unsigned long) -1;
 327
 328   b = NULL;
 329
 330   if (line_num <= sf->num_lines)
 331     b = (Sym *) sf->line[line_num - 1];
 332
 333   if (!b)
 334     {
 335       for (i = 0; i < width; i++)
 336         buf[i] = ' ';
 337       buf[width] = '\0';
 338     }
 339   else
 340     {
 341       char tmpbuf[NBBS * 30];
 342       char *p;
 343       unsigned long ncalls;
 344       int ncalls_set;
 345       unsigned int len;
 346
 347       ++num_executable_lines;
 348
 349       p = tmpbuf;
 350       *p = '\0';
 351
 352       ncalls = 0;
 353       ncalls_set = 0;
 354
 355       /* If this is a function entry point, label the line no matter what.
 356          Otherwise, we're in the middle of a function, so check to see
 357          if the first basic-block address is larger than the starting
 358          address of the line.  If so, then this line begins with a
 359          a portion of the previous basic-block, so print that prior
 360          execution count (if bb_annotate_all_lines is set).  */
 361       if (b->is_func)
 362         {
 363           p += sprintf (p, "%lu", b->ncalls);
 364           last_count = b->ncalls;
 365           last_print = last_count;
 366           ncalls = b->ncalls;
 367           ncalls_set = 1;
 368         }
 369       else if (bb_annotate_all_lines
 370                && b->bb_addr[0] && b->bb_addr[0] > b->addr)
 371         {
 372           p += sprintf (p, "%lu", last_count);
 373           last_print = last_count;
 374           ncalls = last_count;
 375           ncalls_set = 1;
 376         }
 377
 378       /* Loop through all of this line's basic-blocks.  For each one,
 379          update last_count, then compress sequential identical counts
 380          (if bb_annotate_all_lines) and print the execution count.  */
 381
 382       for (i = 0; i < NBBS && b->bb_addr[i]; i++)
 383         {
 384           last_count = b->bb_calls[i];
 385           if (! ncalls_set)
 386             {
 387               ncalls = 0;
 388               ncalls_set = 1;
 389             }
 390           ncalls += last_count;
 391
 392           if (bb_annotate_all_lines && last_count == last_print)
 393             continue;
 394
 395           if (p > tmpbuf)
 396             *p++ = ',';
 397           p += sprintf (p, "%lu", last_count);
 398
 399           last_print = last_count;
 400         }
 401
 402       /* We're done.  If nothing has been printed on this line,
 403          print the last execution count (bb_annotate_all_lines),
 404          which could be from either a previous line (if there were
 405          no BBs on this line), or from this line (if all our BB
 406          counts were compressed out because they were identical).  */
 407
 408       if (bb_annotate_all_lines && p == tmpbuf)
 409         {
 410           p += sprintf (p, "%lu", last_count);
 411           ncalls = last_count;
 412           ncalls_set = 1;
 413         }
 414
 415       if (! ncalls_set)
 416         {
 417           unsigned int c;
 418
 419           for (c = 0; c < width; c++)
 420             buf[c] = ' ';
 421           buf[width] = '\0';
 422           return;
 423         }
 424
 425       ++num_lines_executed;
 426
 427       if (ncalls < bb_min_calls)
 428         {
 429           strcpy (tmpbuf, "#####");
 430           p = tmpbuf + 5;
 431         }
 432
 433       strcpy (p, " -> ");
 434       p += 4;
 435
 436       len = p - tmpbuf;
 437       if (len >= width)
 438         {
 439           strncpy (buf, tmpbuf, width);
 440           buf[width] = '\0';
 441         }
 442       else
 443         {
 444           unsigned int c;
 445
 446           strcpy (buf + width - len, tmpbuf);
 447           for (c = 0; c < width - len; ++c)
 448             buf[c] = ' ';
 449         }
 450     }
 451 }
 452
 453 /* Annotate the files named in SOURCE_FILES with basic-block statistics
 454    (execution counts).  After each source files, a few statistics
 455    regarding that source file are printed.  */
 456
 457 void
 458 print_annotated_source (void)
 459 {
 460   Sym *sym, *line_stats, *new_line;
 461   Source_File *sf;
 462   int i, table_len;
 463   FILE *ofp;
 464
 465   /* Find maximum line number for each source file that user is
 466      interested in:  */
 467   for (sym = symtab.base; sym < symtab.limit; ++sym)
 468     {
 469       /* Accept symbol if it's file is known, its line number is
 470          bigger than anything we have seen for that file so far and
 471          if it's in the INCL_ANNO table or there is no INCL_ANNO
 472          table and it does not appear in the EXCL_ANNO table.  */
 473       if (sym->file && sym->line_num > sym->file->num_lines
 474           && (sym_lookup (&syms[INCL_ANNO], sym->addr)
 475               || (syms[INCL_ANNO].len == 0
 476                   && !sym_lookup (&syms[EXCL_ANNO], sym->addr))))
 477         {
 478           sym->file->num_lines = sym->line_num;
 479         }
 480     }
 481
 482   /* Allocate line descriptors:  */
 483   for (sf = first_src_file; sf; sf = sf->next)
 484     {
 485       if (sf->num_lines > 0)
 486         {
 487           sf->line = (void **) xmalloc (sf->num_lines * sizeof (sf->line[0]));
 488           memset (sf->line, 0, sf->num_lines * sizeof (sf->line[0]));
 489         }
 490     }
 491
 492   /* Count executions per line:  */
 493   for (sym = symtab.base; sym < symtab.limit; ++sym)
 494     {
 495       if (sym->file && sym->file->num_lines
 496           && (sym_lookup (&syms[INCL_ANNO], sym->addr)
 497               || (syms[INCL_ANNO].len == 0
 498                   && !sym_lookup (&syms[EXCL_ANNO], sym->addr))))
 499         {
 500           sym->file->ncalls += sym->ncalls;
 501           line_stats = (Sym *) sym->file->line[sym->line_num - 1];
 502
 503           if (!line_stats)
 504             {
 505               /* Common case has at most one basic-block per source line:  */
 506               sym->file->line[sym->line_num - 1] = sym;
 507             }
 508           else if (!line_stats->addr)
 509             {
 510               /* sym is the 3rd .. nth basic block for this line:  */
 511               line_stats->ncalls += sym->ncalls;
 512             }
 513           else
 514             {
 515               /* sym is the second basic block for this line.  */
 516               new_line = (Sym *) xmalloc (sizeof (*new_line));
 517               *new_line = *line_stats;
 518               new_line->addr = 0;
 519               new_line->ncalls += sym->ncalls;
 520               sym->file->line[sym->line_num - 1] = new_line;
 521             }
 522         }
 523     }
 524
 525   /* Plod over source files, annotating them:  */
 526   for (sf = first_src_file; sf; sf = sf->next)
 527     {
 528       if (!sf->num_lines || (ignore_zeros && sf->ncalls == 0))
 529         continue;
 530
 531       num_executable_lines = num_lines_executed = 0;
 532
 533       ofp = annotate_source (sf, 16, annotate_with_count, sf);
 534       if (!ofp)
 535         continue;
 536
 537       if (bb_table_length > 0)
 538         {
 539           fprintf (ofp, _("\n\nTop %d Lines:\n\n     Line      Count\n\n"),
 540                    bb_table_length);
 541
 542           /* Abuse line arrays---it's not needed anymore:  */
 543           qsort (sf->line, sf->num_lines, sizeof (sf->line[0]), cmp_ncalls);
 544           table_len = bb_table_length;
 545
 546           if (table_len > sf->num_lines)
 547             table_len = sf->num_lines;
 548
 549           for (i = 0; i < table_len; ++i)
 550             {
 551               sym = (Sym *) sf->line[i];
 552
 553               if (!sym || sym->ncalls == 0)
 554                   break;
 555
 556               fprintf (ofp, "%9d %10lu\n", sym->line_num, sym->ncalls);
 557             }
 558         }
 559
 560       free (sf->line);
 561       sf->line = 0;
 562
 563       fprintf (ofp, _("\nExecution Summary:\n\n"));
 564       fprintf (ofp, _("%9ld   Executable lines in this file\n"),
 565                num_executable_lines);
 566       fprintf (ofp, _("%9ld   Lines executed\n"), num_lines_executed);
 567       fprintf (ofp, _("%9.2f   Percent of the file executed\n"),
 568                num_executable_lines
 569                ? 100.0 * num_lines_executed / (double) num_executable_lines
 570                : 100.0);
 571       fprintf (ofp, _("\n%9lu   Total number of line executions\n"),
 572                sf->ncalls);
 573       fprintf (ofp, _("%9.2f   Average executions per line\n"),
 574                num_executable_lines
 575                ? (double) sf->ncalls / (double) num_executable_lines
 576                : 0.0);
 577
 578       if (ofp != stdout)
 579         fclose (ofp);
 580     }
 581 }