libgcc/libgcov.h

   1 /* Header file for libgcov-*.c.
   2    Copyright (C) 1996-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GCC.
   5
   6    GCC is free software; you can redistribute it and/or modify it under
   7    the terms of the GNU General Public License as published by the Free
   8    Software Foundation; either version 3, or (at your option) any later
   9    version.
  10
  11    GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14    for more details.
  15
  16    Under Section 7 of GPL version 3, you are granted additional
  17    permissions described in the GCC Runtime Library Exception, version
  18    3.1, as published by the Free Software Foundation.
  19
  20    You should have received a copy of the GNU General Public License and
  21    a copy of the GCC Runtime Library Exception along with this program;
  22    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23    <http://www.gnu.org/licenses/>.  */
  24
  25 #ifndef GCC_LIBGCOV_H
  26 #define GCC_LIBGCOV_H
  27
  28 /* work around the poisoned malloc/calloc in system.h.  */
  29 #ifndef xmalloc
  30 #define xmalloc malloc
  31 #endif
  32 #ifndef xcalloc
  33 #define xcalloc calloc
  34 #endif
  35
  36 #ifndef IN_GCOV_TOOL
  37 /* About the target.  */
  38 /* This path will be used by libgcov runtime.  */
  39
  40 #include "tconfig.h"
  41 #include "auto-target.h"
  42 #include "tsystem.h"
  43 #include "coretypes.h"
  44 #include "tm.h"
  45 #include "libgcc_tm.h"
  46 #include "gcov.h"
  47
  48 #if __CHAR_BIT__ == 8
  49 typedef unsigned gcov_unsigned_t __attribute__ ((mode (SI)));
  50 typedef unsigned gcov_position_t __attribute__ ((mode (SI)));
  51 #if LONG_LONG_TYPE_SIZE > 32
  52 typedef signed gcov_type __attribute__ ((mode (DI)));
  53 typedef unsigned gcov_type_unsigned __attribute__ ((mode (DI)));
  54 #else
  55 typedef signed gcov_type __attribute__ ((mode (SI)));
  56 typedef unsigned gcov_type_unsigned __attribute__ ((mode (SI)));
  57 #endif
  58 #else
  59 #if __CHAR_BIT__ == 16
  60 typedef unsigned gcov_unsigned_t __attribute__ ((mode (HI)));
  61 typedef unsigned gcov_position_t __attribute__ ((mode (HI)));
  62 #if LONG_LONG_TYPE_SIZE > 32
  63 typedef signed gcov_type __attribute__ ((mode (SI)));
  64 typedef unsigned gcov_type_unsigned __attribute__ ((mode (SI)));
  65 #else
  66 typedef signed gcov_type __attribute__ ((mode (HI)));
  67 typedef unsigned gcov_type_unsigned __attribute__ ((mode (HI)));
  68 #endif
  69 #else
  70 typedef unsigned gcov_unsigned_t __attribute__ ((mode (QI)));
  71 typedef unsigned gcov_position_t __attribute__ ((mode (QI)));
  72 #if LONG_LONG_TYPE_SIZE > 32
  73 typedef signed gcov_type __attribute__ ((mode (HI)));
  74 typedef unsigned gcov_type_unsigned __attribute__ ((mode (HI)));
  75 #else
  76 typedef signed gcov_type __attribute__ ((mode (QI)));
  77 typedef unsigned gcov_type_unsigned __attribute__ ((mode (QI)));
  78 #endif
  79 #endif
  80 #endif
  81
  82 #if defined (TARGET_POSIX_IO)
  83 #define GCOV_LOCKED 1
  84 #else
  85 #define GCOV_LOCKED 0
  86 #endif
  87
  88 #ifndef GCOV_SUPPORTS_ATOMIC
  89 /* Detect whether target can support atomic update of profilers.  */
  90 #if __SIZEOF_LONG_LONG__ == 4 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
  91 #define GCOV_SUPPORTS_ATOMIC 1
  92 #else
  93 #if __SIZEOF_LONG_LONG__ == 8 && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
  94 #define GCOV_SUPPORTS_ATOMIC 1
  95 #else
  96 #define GCOV_SUPPORTS_ATOMIC 0
  97 #endif
  98 #endif
  99 #endif
 100
 101 /* In libgcov we need these functions to be extern, so prefix them with
 102    __gcov.  In libgcov they must also be hidden so that the instance in
 103    the executable is not also used in a DSO.  */
 104 #define gcov_var __gcov_var
 105 #define gcov_open __gcov_open
 106 #define gcov_close __gcov_close
 107 #define gcov_write_tag_length __gcov_write_tag_length
 108 #define gcov_position __gcov_position
 109 #define gcov_seek __gcov_seek
 110 #define gcov_rewrite __gcov_rewrite
 111 #define gcov_is_error __gcov_is_error
 112 #define gcov_write_unsigned __gcov_write_unsigned
 113 #define gcov_write_counter __gcov_write_counter
 114 #define gcov_write_summary __gcov_write_summary
 115 #define gcov_read_unsigned __gcov_read_unsigned
 116 #define gcov_read_counter __gcov_read_counter
 117 #define gcov_read_summary __gcov_read_summary
 118
 119 #else /* IN_GCOV_TOOL */
 120 /* About the host.  */
 121 /* This path will be compiled for the host and linked into
 122    gcov-tool binary.  */
 123
 124 #include "config.h"
 125 #include "system.h"
 126 #include "coretypes.h"
 127 #include "tm.h"
 128
 129 typedef unsigned gcov_unsigned_t;
 130 typedef unsigned gcov_position_t;
 131 /* gcov_type is typedef'd elsewhere for the compiler */
 132 #if defined (HOST_HAS_F_SETLKW)
 133 #define GCOV_LOCKED 1
 134 #else
 135 #define GCOV_LOCKED 0
 136 #endif
 137
 138 /* Some Macros specific to gcov-tool.  */
 139
 140 #define L_gcov 1
 141 #define L_gcov_merge_add 1
 142 #define L_gcov_merge_topn 1
 143 #define L_gcov_merge_ior 1
 144 #define L_gcov_merge_time_profile 1
 145
 146 extern gcov_type gcov_read_counter_mem ();
 147 extern unsigned gcov_get_merge_weight ();
 148 extern struct gcov_info *gcov_list;
 149
 150 #endif /* !IN_GCOV_TOOL */
 151
 152 #if defined(inhibit_libc)
 153 #define IN_LIBGCOV (-1)
 154 #else
 155 #define IN_LIBGCOV 1
 156 #if defined(L_gcov)
 157 #define GCOV_LINKAGE /* nothing */
 158 #endif
 159 #endif
 160
 161 /* Poison these, so they don't accidentally slip in.  */
 162 #pragma GCC poison gcov_write_string gcov_write_tag gcov_write_length
 163 #pragma GCC poison gcov_time
 164
 165 #ifdef HAVE_GAS_HIDDEN
 166 #define ATTRIBUTE_HIDDEN  __attribute__ ((__visibility__ ("hidden")))
 167 #else
 168 #define ATTRIBUTE_HIDDEN
 169 #endif
 170
 171 #include "gcov-io.h"
 172
 173 /* Structures embedded in coveraged program.  The structures generated
 174    by write_profile must match these.  */
 175
 176 /* Information about counters for a single function.  */
 177 struct gcov_ctr_info
 178 {
 179   gcov_unsigned_t num;          /* number of counters.  */
 180   gcov_type *values;            /* their values.  */
 181 };
 182
 183 /* Information about a single function.  This uses the trailing array
 184    idiom. The number of counters is determined from the merge pointer
 185    array in gcov_info.  The key is used to detect which of a set of
 186    comdat functions was selected -- it points to the gcov_info object
 187    of the object file containing the selected comdat function.  */
 188
 189 struct gcov_fn_info
 190 {
 191   const struct gcov_info *key;          /* comdat key */
 192   gcov_unsigned_t ident;                /* unique ident of function */
 193   gcov_unsigned_t lineno_checksum;      /* function lineo_checksum */
 194   gcov_unsigned_t cfg_checksum;         /* function cfg checksum */
 195   struct gcov_ctr_info ctrs[1];         /* instrumented counters */
 196 };
 197
 198 /* Type of function used to merge counters.  */
 199 typedef void (*gcov_merge_fn) (gcov_type *, gcov_unsigned_t);
 200
 201 /* Information about a single object file.  */
 202 struct gcov_info
 203 {
 204   gcov_unsigned_t version;      /* expected version number */
 205   struct gcov_info *next;       /* link to next, used by libgcov */
 206
 207   gcov_unsigned_t stamp;        /* uniquifying time stamp */
 208   const char *filename;         /* output file name */
 209
 210   gcov_merge_fn merge[GCOV_COUNTERS];  /* merge functions (null for
 211                                           unused) */
 212
 213   unsigned n_functions;         /* number of functions */
 214
 215 #ifndef IN_GCOV_TOOL
 216   const struct gcov_fn_info *const *functions; /* pointer to pointers
 217                                                   to function information  */
 218 #else
 219   const struct gcov_fn_info **functions;
 220 #endif /* !IN_GCOV_TOOL */
 221 };
 222
 223 /* Root of a program/shared-object state */
 224 struct gcov_root
 225 {
 226   struct gcov_info *list;
 227   unsigned dumped : 1;  /* counts have been dumped.  */
 228   unsigned run_counted : 1;  /* run has been accounted for.  */
 229   struct gcov_root *next;
 230   struct gcov_root *prev;
 231 };
 232
 233 extern struct gcov_root __gcov_root ATTRIBUTE_HIDDEN;
 234
 235 struct gcov_master
 236 {
 237   gcov_unsigned_t version;
 238   struct gcov_root *root;
 239 };
 240
 241 struct indirect_call_tuple
 242 {
 243   /* Callee function.  */
 244   void *callee;
 245
 246   /* Pointer to counters.  */
 247   gcov_type *counters;
 248 };
 249
 250 /* Exactly one of these will be active in the process.  */
 251 extern struct gcov_master __gcov_master;
 252
 253 /* Dump a set of gcov objects.  */
 254 extern void __gcov_dump_one (struct gcov_root *) ATTRIBUTE_HIDDEN;
 255
 256 /* Register a new object file module.  */
 257 extern void __gcov_init (struct gcov_info *) ATTRIBUTE_HIDDEN;
 258
 259 /* GCOV exit function registered via a static destructor.  */
 260 extern void __gcov_exit (void) ATTRIBUTE_HIDDEN;
 261
 262 /* Function to reset all counters to 0.  Both externally visible (and
 263    overridable) and internal version.  */
 264 extern void __gcov_reset_int (void) ATTRIBUTE_HIDDEN;
 265
 266 /* User function to enable early write of profile information so far.  */
 267 extern void __gcov_dump_int (void) ATTRIBUTE_HIDDEN;
 268
 269 /* Lock critical section for __gcov_dump and __gcov_reset functions.  */
 270 extern void __gcov_lock (void) ATTRIBUTE_HIDDEN;
 271
 272 /* Unlock critical section for __gcov_dump and __gcov_reset functions.  */
 273 extern void __gcov_unlock (void) ATTRIBUTE_HIDDEN;
 274
 275 /* The merge function that just sums the counters.  */
 276 extern void __gcov_merge_add (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 277
 278 /* The merge function to select the minimum valid counter value.  */
 279 extern void __gcov_merge_time_profile (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 280
 281 /* The merge function to choose the most common N values.  */
 282 extern void __gcov_merge_topn (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 283
 284 /* The merge function that just ors the counters together.  */
 285 extern void __gcov_merge_ior (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 286
 287 /* The profiler functions.  */
 288 extern void __gcov_interval_profiler (gcov_type *, gcov_type, int, unsigned);
 289 extern void __gcov_interval_profiler_atomic (gcov_type *, gcov_type, int,
 290                                              unsigned);
 291 extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
 292 extern void __gcov_pow2_profiler_atomic (gcov_type *, gcov_type);
 293 extern void __gcov_topn_values_profiler (gcov_type *, gcov_type);
 294 extern void __gcov_topn_values_profiler_atomic (gcov_type *, gcov_type);
 295 extern void __gcov_indirect_call_profiler_v4 (gcov_type, void *);
 296 extern void __gcov_indirect_call_profiler_v4_atomic (gcov_type, void *);
 297 extern void __gcov_time_profiler (gcov_type *);
 298 extern void __gcov_time_profiler_atomic (gcov_type *);
 299 extern void __gcov_average_profiler (gcov_type *, gcov_type);
 300 extern void __gcov_average_profiler_atomic (gcov_type *, gcov_type);
 301 extern void __gcov_ior_profiler (gcov_type *, gcov_type);
 302 extern void __gcov_ior_profiler_atomic (gcov_type *, gcov_type);
 303
 304 #ifndef inhibit_libc
 305 /* The wrappers around some library functions..  */
 306 extern pid_t __gcov_fork (void) ATTRIBUTE_HIDDEN;
 307 extern int __gcov_execl (const char *, char *, ...) ATTRIBUTE_HIDDEN;
 308 extern int __gcov_execlp (const char *, char *, ...) ATTRIBUTE_HIDDEN;
 309 extern int __gcov_execle (const char *, char *, ...) ATTRIBUTE_HIDDEN;
 310 extern int __gcov_execv (const char *, char *const []) ATTRIBUTE_HIDDEN;
 311 extern int __gcov_execvp (const char *, char *const []) ATTRIBUTE_HIDDEN;
 312 extern int __gcov_execve (const char *, char  *const [], char *const [])
 313   ATTRIBUTE_HIDDEN;
 314
 315 /* Functions that only available in libgcov.  */
 316 GCOV_LINKAGE int gcov_open (const char */*name*/) ATTRIBUTE_HIDDEN;
 317 GCOV_LINKAGE void gcov_write_counter (gcov_type) ATTRIBUTE_HIDDEN;
 318 GCOV_LINKAGE void gcov_write_tag_length (gcov_unsigned_t, gcov_unsigned_t)
 319     ATTRIBUTE_HIDDEN;
 320 GCOV_LINKAGE void gcov_write_summary (gcov_unsigned_t /*tag*/,
 321                                       const struct gcov_summary *)
 322     ATTRIBUTE_HIDDEN;
 323 GCOV_LINKAGE void gcov_seek (gcov_position_t /*position*/) ATTRIBUTE_HIDDEN;
 324 GCOV_LINKAGE void gcov_rewrite (void) ATTRIBUTE_HIDDEN;
 325
 326 /* "Counts" stored in gcda files can be a real counter value, or
 327    an target address. When differentiate these two types because
 328    when manipulating counts, we should only change real counter values,
 329    rather target addresses.  */
 330
 331 static inline gcov_type
 332 gcov_get_counter (void)
 333 {
 334 #ifndef IN_GCOV_TOOL
 335   /* This version is for reading count values in libgcov runtime:
 336      we read from gcda files.  */
 337
 338   return gcov_read_counter ();
 339 #else
 340   /* This version is for gcov-tool. We read the value from memory and
 341      multiply it by the merge weight.  */
 342
 343   return gcov_read_counter_mem () * gcov_get_merge_weight ();
 344 #endif
 345 }
 346
 347 /* Similar function as gcov_get_counter(), but do not scale
 348    when read value is equal to IGNORE_SCALING.  */
 349
 350 static inline gcov_type
 351 gcov_get_counter_ignore_scaling (gcov_type ignore_scaling ATTRIBUTE_UNUSED)
 352 {
 353 #ifndef IN_GCOV_TOOL
 354   /* This version is for reading count values in libgcov runtime:
 355      we read from gcda files.  */
 356
 357   return gcov_read_counter ();
 358 #else
 359   /* This version is for gcov-tool. We read the value from memory and
 360      multiply it by the merge weight.  */
 361
 362   gcov_type v = gcov_read_counter_mem ();
 363   if (v != ignore_scaling)
 364     v *= gcov_get_merge_weight ();
 365
 366   return v;
 367 #endif
 368 }
 369
 370 /* Similar function as gcov_get_counter(), but handles target address
 371    counters.  */
 372
 373 static inline gcov_type
 374 gcov_get_counter_target (void)
 375 {
 376 #ifndef IN_GCOV_TOOL
 377   /* This version is for reading count target values in libgcov runtime:
 378      we read from gcda files.  */
 379
 380   return gcov_read_counter ();
 381 #else
 382   /* This version is for gcov-tool.  We read the value from memory and we do NOT
 383      multiply it by the merge weight.  */
 384
 385   return gcov_read_counter_mem ();
 386 #endif
 387 }
 388
 389 /* Add VALUE to *COUNTER and make it with atomic operation
 390    if USE_ATOMIC is true.  */
 391
 392 static inline void
 393 gcov_counter_add (gcov_type *counter, gcov_type value,
 394                   int use_atomic ATTRIBUTE_UNUSED)
 395 {
 396 #if GCOV_SUPPORTS_ATOMIC
 397   if (use_atomic)
 398     __atomic_fetch_add (counter, value, __ATOMIC_RELAXED);
 399   else
 400 #endif
 401     *counter += value;
 402 }
 403
 404 /* Set NODE to memory location COUNTER and make it with atomic operation
 405    if USE_ATOMIC is true.  */
 406
 407 static inline int
 408 gcov_counter_set_if_null (gcov_type *counter, struct gcov_kvp *node,
 409                           int use_atomic ATTRIBUTE_UNUSED)
 410 {
 411 #if GCOV_SUPPORTS_ATOMIC
 412   if (use_atomic)
 413     return !__sync_val_compare_and_swap (counter, NULL, (intptr_t)node);
 414   else
 415 #endif
 416     {
 417       *counter = (intptr_t)node;
 418       return 1;
 419     }
 420 }
 421
 422 /* Add key value pair VALUE:COUNT to a top N COUNTERS.  When INCREMENT_TOTAL
 423    is true, add COUNT to total of the TOP counter.  If USE_ATOMIC is true,
 424    do it in atomic way.  */
 425
 426 static inline void
 427 gcov_topn_add_value (gcov_type *counters, gcov_type value, gcov_type count,
 428                      int use_atomic, int increment_total)
 429 {
 430   if (increment_total)
 431     gcov_counter_add (&counters[0], 1, use_atomic);
 432
 433   struct gcov_kvp *prev_node = NULL;
 434   struct gcov_kvp *minimal_node = NULL;
 435   struct gcov_kvp *current_node  = (struct gcov_kvp *)counters[2];
 436
 437   while (current_node)
 438     {
 439       if (current_node->value == value)
 440         {
 441           gcov_counter_add (&current_node->count, count, use_atomic);
 442           return;
 443         }
 444
 445       if (minimal_node == NULL
 446           || current_node->count < minimal_node->count)
 447         minimal_node = current_node;
 448
 449       prev_node = current_node;
 450       current_node = current_node->next;
 451     }
 452
 453   if (counters[1] == GCOV_TOPN_MAXIMUM_TRACKED_VALUES)
 454     {
 455       if (--minimal_node->count < count)
 456         {
 457           minimal_node->value = value;
 458           minimal_node->count = count;
 459         }
 460     }
 461   else
 462     {
 463       struct gcov_kvp *new_node
 464         = (struct gcov_kvp *)xcalloc (1, sizeof (struct gcov_kvp));
 465       new_node->value = value;
 466       new_node->count = count;
 467
 468       int success = 0;
 469       if (!counters[2])
 470         success = gcov_counter_set_if_null (&counters[2], new_node, use_atomic);
 471       else if (prev_node && !prev_node->next)
 472         success = gcov_counter_set_if_null ((gcov_type *)&prev_node->next,
 473                                             new_node, use_atomic);
 474
 475       /* Increment number of nodes.  */
 476       if (success)
 477         gcov_counter_add (&counters[1], 1, use_atomic);
 478     }
 479 }
 480
 481 #endif /* !inhibit_libc */
 482
 483 #endif /* GCC_LIBGCOV_H */