1 /*===- InstrProfilingFile.c - Write instrumentation to a file -------------===*\
2 |*
3 |* The LLVM Compiler Infrastructure
4 |*
5 |* This file is distributed under the University of Illinois Open Source
6 |* License. See LICENSE.TXT for details.
7 |*
8 \*===----------------------------------------------------------------------===*/
9
10 #include "InstrProfiling.h"
11 #include "InstrProfilingInternal.h"
12 #include "InstrProfilingUtil.h"
13 #include <errno.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #ifdef _MSC_VER
18 /* For _alloca. */
19 #include <malloc.h>
20 #endif
21 #if defined(_WIN32)
22 #include "WindowsMMap.h"
23 /* For _chsize_s */
24 #include <io.h>
25 #else
26 #include <sys/file.h>
27 #include <sys/mman.h>
28 #include <unistd.h>
29 #if defined(__linux__)
30 #include <sys/types.h>
31 #endif
32 #endif
33
34 /* From where is profile name specified.
35 * The order the enumerators define their
36 * precedence. Re-order them may lead to
37 * runtime behavior change. */
38 typedef enum ProfileNameSpecifier {
39 PNS_unknown = 0,
40 PNS_default,
41 PNS_command_line,
42 PNS_environment,
43 PNS_runtime_api
44 } ProfileNameSpecifier;
45
getPNSStr(ProfileNameSpecifier PNS)46 static const char *getPNSStr(ProfileNameSpecifier PNS) {
47 switch (PNS) {
48 case PNS_default:
49 return "default setting";
50 case PNS_command_line:
51 return "command line";
52 case PNS_environment:
53 return "environment variable";
54 case PNS_runtime_api:
55 return "runtime API";
56 default:
57 return "Unknown";
58 }
59 }
60
61 #define MAX_PID_SIZE 16
62 /* Data structure holding the result of parsed filename pattern. */
63 typedef struct lprofFilename {
64 /* File name string possibly with %p or %h specifiers. */
65 const char *FilenamePat;
66 char PidChars[MAX_PID_SIZE];
67 char Hostname[COMPILER_RT_MAX_HOSTLEN];
68 unsigned NumPids;
69 unsigned NumHosts;
70 /* When in-process merging is enabled, this parameter specifies
71 * the total number of profile data files shared by all the processes
72 * spawned from the same binary. By default the value is 1. If merging
73 * is not enabled, its value should be 0. This parameter is specified
74 * by the %[0-9]m specifier. For instance %2m enables merging using
75 * 2 profile data files. %1m is equivalent to %m. Also %m specifier
76 * can only appear once at the end of the name pattern. */
77 unsigned MergePoolSize;
78 ProfileNameSpecifier PNS;
79 } lprofFilename;
80
81 lprofFilename lprofCurFilename = {0, {0}, {0}, 0, 0, 0, PNS_unknown};
82
83 int getpid(void);
84 static int getCurFilenameLength();
85 static const char *getCurFilename(char *FilenameBuf);
doMerging()86 static unsigned doMerging() { return lprofCurFilename.MergePoolSize; }
87
88 /* Return 1 if there is an error, otherwise return 0. */
fileWriter(ProfDataIOVec * IOVecs,uint32_t NumIOVecs,void ** WriterCtx)89 static uint32_t fileWriter(ProfDataIOVec *IOVecs, uint32_t NumIOVecs,
90 void **WriterCtx) {
91 uint32_t I;
92 FILE *File = (FILE *)*WriterCtx;
93 for (I = 0; I < NumIOVecs; I++) {
94 if (fwrite(IOVecs[I].Data, IOVecs[I].ElmSize, IOVecs[I].NumElm, File) !=
95 IOVecs[I].NumElm)
96 return 1;
97 }
98 return 0;
99 }
100
101 COMPILER_RT_VISIBILITY ProfBufferIO *
lprofCreateBufferIOInternal(void * File,uint32_t BufferSz)102 lprofCreateBufferIOInternal(void *File, uint32_t BufferSz) {
103 FreeHook = &free;
104 DynamicBufferIOBuffer = (uint8_t *)calloc(BufferSz, 1);
105 VPBufferSize = BufferSz;
106 return lprofCreateBufferIO(fileWriter, File);
107 }
108
setupIOBuffer()109 static void setupIOBuffer() {
110 const char *BufferSzStr = 0;
111 BufferSzStr = getenv("LLVM_VP_BUFFER_SIZE");
112 if (BufferSzStr && BufferSzStr[0]) {
113 VPBufferSize = atoi(BufferSzStr);
114 DynamicBufferIOBuffer = (uint8_t *)calloc(VPBufferSize, 1);
115 }
116 }
117
118 /* Read profile data in \c ProfileFile and merge with in-memory
119 profile counters. Returns -1 if there is fatal error, otheriwse
120 0 is returned.
121 */
doProfileMerging(FILE * ProfileFile)122 static int doProfileMerging(FILE *ProfileFile) {
123 uint64_t ProfileFileSize;
124 char *ProfileBuffer;
125
126 if (fseek(ProfileFile, 0L, SEEK_END) == -1) {
127 PROF_ERR("Unable to merge profile data, unable to get size: %s\n",
128 strerror(errno));
129 return -1;
130 }
131 ProfileFileSize = ftell(ProfileFile);
132
133 /* Restore file offset. */
134 if (fseek(ProfileFile, 0L, SEEK_SET) == -1) {
135 PROF_ERR("Unable to merge profile data, unable to rewind: %s\n",
136 strerror(errno));
137 return -1;
138 }
139
140 /* Nothing to merge. */
141 if (ProfileFileSize < sizeof(__llvm_profile_header)) {
142 if (ProfileFileSize)
143 PROF_WARN("Unable to merge profile data: %s\n",
144 "source profile file is too small.");
145 return 0;
146 }
147
148 ProfileBuffer = mmap(NULL, ProfileFileSize, PROT_READ, MAP_SHARED | MAP_FILE,
149 fileno(ProfileFile), 0);
150 if (ProfileBuffer == MAP_FAILED) {
151 PROF_ERR("Unable to merge profile data, mmap failed: %s\n",
152 strerror(errno));
153 return -1;
154 }
155
156 if (__llvm_profile_check_compatibility(ProfileBuffer, ProfileFileSize)) {
157 (void)munmap(ProfileBuffer, ProfileFileSize);
158 PROF_WARN("Unable to merge profile data: %s\n",
159 "source profile file is not compatible.");
160 return 0;
161 }
162
163 /* Now start merging */
164 __llvm_profile_merge_from_buffer(ProfileBuffer, ProfileFileSize);
165 (void)munmap(ProfileBuffer, ProfileFileSize);
166
167 return 0;
168 }
169
170 /* Open the profile data for merging. It opens the file in r+b mode with
171 * file locking. If the file has content which is compatible with the
172 * current process, it also reads in the profile data in the file and merge
173 * it with in-memory counters. After the profile data is merged in memory,
174 * the original profile data is truncated and gets ready for the profile
175 * dumper. With profile merging enabled, each executable as well as any of
176 * its instrumented shared libraries dump profile data into their own data file.
177 */
openFileForMerging(const char * ProfileFileName)178 static FILE *openFileForMerging(const char *ProfileFileName) {
179 FILE *ProfileFile;
180 int rc;
181
182 ProfileFile = lprofOpenFileEx(ProfileFileName);
183 if (!ProfileFile)
184 return NULL;
185
186 rc = doProfileMerging(ProfileFile);
187 if (rc || COMPILER_RT_FTRUNCATE(ProfileFile, 0L) ||
188 fseek(ProfileFile, 0L, SEEK_SET) == -1) {
189 PROF_ERR("Profile Merging of file %s failed: %s\n", ProfileFileName,
190 strerror(errno));
191 fclose(ProfileFile);
192 return NULL;
193 }
194 fseek(ProfileFile, 0L, SEEK_SET);
195 return ProfileFile;
196 }
197
198 /* Write profile data to file \c OutputName. */
writeFile(const char * OutputName)199 static int writeFile(const char *OutputName) {
200 int RetVal;
201 FILE *OutputFile;
202
203 if (!doMerging())
204 OutputFile = fopen(OutputName, "ab");
205 else
206 OutputFile = openFileForMerging(OutputName);
207
208 if (!OutputFile)
209 return -1;
210
211 FreeHook = &free;
212 setupIOBuffer();
213 RetVal = lprofWriteData(fileWriter, OutputFile, lprofGetVPDataReader());
214
215 fclose(OutputFile);
216 return RetVal;
217 }
218
truncateCurrentFile(void)219 static void truncateCurrentFile(void) {
220 const char *Filename;
221 char *FilenameBuf;
222 FILE *File;
223 int Length;
224
225 Length = getCurFilenameLength();
226 FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
227 Filename = getCurFilename(FilenameBuf);
228 if (!Filename)
229 return;
230
231 /* Create the directory holding the file, if needed. */
232 if (strchr(Filename, '/') || strchr(Filename, '\\')) {
233 char *Copy = (char *)COMPILER_RT_ALLOCA(Length + 1);
234 strncpy(Copy, Filename, Length + 1);
235 __llvm_profile_recursive_mkdir(Copy);
236 }
237
238 /* Truncate the file. Later we'll reopen and append. */
239 File = fopen(Filename, "w");
240 if (!File)
241 return;
242 fclose(File);
243 }
244
245 static const char *DefaultProfileName = "default.profraw";
resetFilenameToDefault(void)246 static void resetFilenameToDefault(void) {
247 memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
248 lprofCurFilename.FilenamePat = DefaultProfileName;
249 lprofCurFilename.PNS = PNS_default;
250 }
251
containsMergeSpecifier(const char * FilenamePat,int I)252 static int containsMergeSpecifier(const char *FilenamePat, int I) {
253 return (FilenamePat[I] == 'm' ||
254 (FilenamePat[I] >= '1' && FilenamePat[I] <= '9' &&
255 /* If FilenamePat[I] is not '\0', the next byte is guaranteed
256 * to be in-bound as the string is null terminated. */
257 FilenamePat[I + 1] == 'm'));
258 }
259
260 /* Parses the pattern string \p FilenamePat and stores the result to
261 * lprofcurFilename structure. */
parseFilenamePattern(const char * FilenamePat)262 static int parseFilenamePattern(const char *FilenamePat) {
263 int NumPids = 0, NumHosts = 0, I;
264 char *PidChars = &lprofCurFilename.PidChars[0];
265 char *Hostname = &lprofCurFilename.Hostname[0];
266 int MergingEnabled = 0;
267
268 lprofCurFilename.FilenamePat = FilenamePat;
269 /* Check the filename for "%p", which indicates a pid-substitution. */
270 for (I = 0; FilenamePat[I]; ++I)
271 if (FilenamePat[I] == '%') {
272 if (FilenamePat[++I] == 'p') {
273 if (!NumPids++) {
274 if (snprintf(PidChars, MAX_PID_SIZE, "%d", getpid()) <= 0) {
275 PROF_WARN(
276 "Unable to parse filename pattern %s. Using the default name.",
277 FilenamePat);
278 return -1;
279 }
280 }
281 } else if (FilenamePat[I] == 'h') {
282 if (!NumHosts++)
283 if (COMPILER_RT_GETHOSTNAME(Hostname, COMPILER_RT_MAX_HOSTLEN)) {
284 PROF_WARN(
285 "Unable to parse filename pattern %s. Using the default name.",
286 FilenamePat);
287 return -1;
288 }
289 } else if (containsMergeSpecifier(FilenamePat, I)) {
290 if (MergingEnabled) {
291 PROF_WARN("%%m specifier can only be specified once in %s.\n",
292 FilenamePat);
293 return -1;
294 }
295 MergingEnabled = 1;
296 if (FilenamePat[I] == 'm')
297 lprofCurFilename.MergePoolSize = 1;
298 else {
299 lprofCurFilename.MergePoolSize = FilenamePat[I] - '0';
300 I++; /* advance to 'm' */
301 }
302 }
303 }
304
305 lprofCurFilename.NumPids = NumPids;
306 lprofCurFilename.NumHosts = NumHosts;
307 return 0;
308 }
309
parseAndSetFilename(const char * FilenamePat,ProfileNameSpecifier PNS)310 static void parseAndSetFilename(const char *FilenamePat,
311 ProfileNameSpecifier PNS) {
312
313 const char *OldFilenamePat = lprofCurFilename.FilenamePat;
314 ProfileNameSpecifier OldPNS = lprofCurFilename.PNS;
315
316 if (PNS < OldPNS)
317 return;
318
319 if (!FilenamePat)
320 FilenamePat = DefaultProfileName;
321
322 /* When -fprofile-instr-generate=<path> is specified on the
323 * command line, each module will be instrumented with runtime
324 * init call to __llvm_profile_init function which calls
325 * __llvm_profile_override_default_filename. In most of the cases,
326 * the path will be identical, so bypass the parsing completely.
327 */
328 if (OldFilenamePat && !strcmp(OldFilenamePat, FilenamePat)) {
329 lprofCurFilename.PNS = PNS;
330 return;
331 }
332
333 /* When PNS >= OldPNS, the last one wins. */
334 if (!FilenamePat || parseFilenamePattern(FilenamePat))
335 resetFilenameToDefault();
336 lprofCurFilename.PNS = PNS;
337
338 if (!OldFilenamePat) {
339 PROF_NOTE("Set profile file path to \"%s\" via %s.\n",
340 lprofCurFilename.FilenamePat, getPNSStr(PNS));
341 } else {
342 PROF_NOTE("Override old profile path \"%s\" via %s to \"%s\" via %s.\n",
343 OldFilenamePat, getPNSStr(OldPNS), lprofCurFilename.FilenamePat,
344 getPNSStr(PNS));
345 }
346
347 if (!lprofCurFilename.MergePoolSize)
348 truncateCurrentFile();
349 }
350
351 /* Return buffer length that is required to store the current profile
352 * filename with PID and hostname substitutions. */
353 /* The length to hold uint64_t followed by 2 digit pool id including '_' */
354 #define SIGLEN 24
getCurFilenameLength()355 static int getCurFilenameLength() {
356 int Len;
357 if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
358 return 0;
359
360 if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
361 lprofCurFilename.MergePoolSize))
362 return strlen(lprofCurFilename.FilenamePat);
363
364 Len = strlen(lprofCurFilename.FilenamePat) +
365 lprofCurFilename.NumPids * (strlen(lprofCurFilename.PidChars) - 2) +
366 lprofCurFilename.NumHosts * (strlen(lprofCurFilename.Hostname) - 2);
367 if (lprofCurFilename.MergePoolSize)
368 Len += SIGLEN;
369 return Len;
370 }
371
372 /* Return the pointer to the current profile file name (after substituting
373 * PIDs and Hostnames in filename pattern. \p FilenameBuf is the buffer
374 * to store the resulting filename. If no substitution is needed, the
375 * current filename pattern string is directly returned. */
getCurFilename(char * FilenameBuf)376 static const char *getCurFilename(char *FilenameBuf) {
377 int I, J, PidLength, HostNameLength;
378 const char *FilenamePat = lprofCurFilename.FilenamePat;
379
380 if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
381 return 0;
382
383 if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
384 lprofCurFilename.MergePoolSize))
385 return lprofCurFilename.FilenamePat;
386
387 PidLength = strlen(lprofCurFilename.PidChars);
388 HostNameLength = strlen(lprofCurFilename.Hostname);
389 /* Construct the new filename. */
390 for (I = 0, J = 0; FilenamePat[I]; ++I)
391 if (FilenamePat[I] == '%') {
392 if (FilenamePat[++I] == 'p') {
393 memcpy(FilenameBuf + J, lprofCurFilename.PidChars, PidLength);
394 J += PidLength;
395 } else if (FilenamePat[I] == 'h') {
396 memcpy(FilenameBuf + J, lprofCurFilename.Hostname, HostNameLength);
397 J += HostNameLength;
398 } else if (containsMergeSpecifier(FilenamePat, I)) {
399 char LoadModuleSignature[SIGLEN];
400 int S;
401 int ProfilePoolId = getpid() % lprofCurFilename.MergePoolSize;
402 S = snprintf(LoadModuleSignature, SIGLEN, "%" PRIu64 "_%d",
403 lprofGetLoadModuleSignature(), ProfilePoolId);
404 if (S == -1 || S > SIGLEN)
405 S = SIGLEN;
406 memcpy(FilenameBuf + J, LoadModuleSignature, S);
407 J += S;
408 if (FilenamePat[I] != 'm')
409 I++;
410 }
411 /* Drop any unknown substitutions. */
412 } else
413 FilenameBuf[J++] = FilenamePat[I];
414 FilenameBuf[J] = 0;
415
416 return FilenameBuf;
417 }
418
419 /* Returns the pointer to the environment variable
420 * string. Returns null if the env var is not set. */
getFilenamePatFromEnv(void)421 static const char *getFilenamePatFromEnv(void) {
422 const char *Filename = getenv("LLVM_PROFILE_FILE");
423 if (!Filename || !Filename[0])
424 return 0;
425 return Filename;
426 }
427
428 /* This method is invoked by the runtime initialization hook
429 * InstrProfilingRuntime.o if it is linked in. Both user specified
430 * profile path via -fprofile-instr-generate= and LLVM_PROFILE_FILE
431 * environment variable can override this default value. */
432 COMPILER_RT_VISIBILITY
__llvm_profile_initialize_file(void)433 void __llvm_profile_initialize_file(void) {
434 const char *FilenamePat;
435
436 FilenamePat = getFilenamePatFromEnv();
437 parseAndSetFilename(FilenamePat, FilenamePat ? PNS_environment : PNS_default);
438 }
439
440 /* This API is directly called by the user application code. It has the
441 * highest precedence compared with LLVM_PROFILE_FILE environment variable
442 * and command line option -fprofile-instr-generate=<profile_name>.
443 */
444 COMPILER_RT_VISIBILITY
__llvm_profile_set_filename(const char * FilenamePat)445 void __llvm_profile_set_filename(const char *FilenamePat) {
446 parseAndSetFilename(FilenamePat, PNS_runtime_api);
447 }
448
449 /*
450 * This API is invoked by the global initializers emitted by Clang/LLVM when
451 * -fprofile-instr-generate=<..> is specified (vs -fprofile-instr-generate
452 * without an argument). This option has lower precedence than the
453 * LLVM_PROFILE_FILE environment variable.
454 */
455 COMPILER_RT_VISIBILITY
__llvm_profile_override_default_filename(const char * FilenamePat)456 void __llvm_profile_override_default_filename(const char *FilenamePat) {
457 parseAndSetFilename(FilenamePat, PNS_command_line);
458 }
459
460 /* The public API for writing profile data into the file with name
461 * set by previous calls to __llvm_profile_set_filename or
462 * __llvm_profile_override_default_filename or
463 * __llvm_profile_initialize_file. */
464 COMPILER_RT_VISIBILITY
__llvm_profile_write_file(void)465 int __llvm_profile_write_file(void) {
466 int rc, Length;
467 const char *Filename;
468 char *FilenameBuf;
469
470 Length = getCurFilenameLength();
471 FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
472 Filename = getCurFilename(FilenameBuf);
473
474 /* Check the filename. */
475 if (!Filename) {
476 PROF_ERR("Failed to write file : %s\n", "Filename not set");
477 return -1;
478 }
479
480 /* Check if there is llvm/runtime version mismatch. */
481 if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {
482 PROF_ERR("Runtime and instrumentation version mismatch : "
483 "expected %d, but get %d\n",
484 INSTR_PROF_RAW_VERSION,
485 (int)GET_VERSION(__llvm_profile_get_version()));
486 return -1;
487 }
488
489 /* Write profile data to the file. */
490 rc = writeFile(Filename);
491 if (rc)
492 PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno));
493 return rc;
494 }
495
writeFileWithoutReturn(void)496 static void writeFileWithoutReturn(void) { __llvm_profile_write_file(); }
497
498 COMPILER_RT_VISIBILITY
__llvm_profile_register_write_file_atexit(void)499 int __llvm_profile_register_write_file_atexit(void) {
500 static int HasBeenRegistered = 0;
501
502 if (HasBeenRegistered)
503 return 0;
504
505 lprofSetupValueProfiler();
506
507 HasBeenRegistered = 1;
508 return atexit(writeFileWithoutReturn);
509 }
510