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 #if !defined(__Fuchsia__)
11 
12 #include <errno.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #ifdef _MSC_VER
17 /* For _alloca. */
18 #include <malloc.h>
19 #endif
20 #if defined(_WIN32)
21 #include "WindowsMMap.h"
22 /* For _chsize_s */
23 #include <io.h>
24 #include <process.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 #include "InstrProfiling.h"
35 #include "InstrProfilingInternal.h"
36 #include "InstrProfilingUtil.h"
37 
38 /* From where is profile name specified.
39  * The order the enumerators define their
40  * precedence. Re-order them may lead to
41  * runtime behavior change. */
42 typedef enum ProfileNameSpecifier {
43   PNS_unknown = 0,
44   PNS_default,
45   PNS_command_line,
46   PNS_environment,
47   PNS_runtime_api
48 } ProfileNameSpecifier;
49 
getPNSStr(ProfileNameSpecifier PNS)50 static const char *getPNSStr(ProfileNameSpecifier PNS) {
51   switch (PNS) {
52   case PNS_default:
53     return "default setting";
54   case PNS_command_line:
55     return "command line";
56   case PNS_environment:
57     return "environment variable";
58   case PNS_runtime_api:
59     return "runtime API";
60   default:
61     return "Unknown";
62   }
63 }
64 
65 #define MAX_PID_SIZE 16
66 /* Data structure holding the result of parsed filename pattern. */
67 typedef struct lprofFilename {
68   /* File name string possibly with %p or %h specifiers. */
69   const char *FilenamePat;
70   /* A flag indicating if FilenamePat's memory is allocated
71    * by runtime. */
72   unsigned OwnsFilenamePat;
73   const char *ProfilePathPrefix;
74   const char *Filename;
75   char PidChars[MAX_PID_SIZE];
76   char Hostname[COMPILER_RT_MAX_HOSTLEN];
77   unsigned NumPids;
78   unsigned NumHosts;
79   /* When in-process merging is enabled, this parameter specifies
80    * the total number of profile data files shared by all the processes
81    * spawned from the same binary. By default the value is 1. If merging
82    * is not enabled, its value should be 0. This parameter is specified
83    * by the %[0-9]m specifier. For instance %2m enables merging using
84    * 2 profile data files. %1m is equivalent to %m. Also %m specifier
85    * can only appear once at the end of the name pattern. */
86   unsigned MergePoolSize;
87   ProfileNameSpecifier PNS;
88 } lprofFilename;
89 
90 COMPILER_RT_WEAK lprofFilename lprofCurFilename = {0,   0, 0, 0, {0},
91                                                    {0}, 0, 0, 0, PNS_unknown};
92 
93 static int getCurFilenameLength();
94 static const char *getCurFilename(char *FilenameBuf, int ForceUseBuf);
doMerging()95 static unsigned doMerging() { return lprofCurFilename.MergePoolSize; }
96 
97 /* Return 1 if there is an error, otherwise return  0.  */
fileWriter(ProfDataWriter * This,ProfDataIOVec * IOVecs,uint32_t NumIOVecs)98 static uint32_t fileWriter(ProfDataWriter *This, ProfDataIOVec *IOVecs,
99                            uint32_t NumIOVecs) {
100   uint32_t I;
101   FILE *File = (FILE *)This->WriterCtx;
102   for (I = 0; I < NumIOVecs; I++) {
103     if (IOVecs[I].Data) {
104       if (fwrite(IOVecs[I].Data, IOVecs[I].ElmSize, IOVecs[I].NumElm, File) !=
105           IOVecs[I].NumElm)
106         return 1;
107     } else {
108       if (fseek(File, IOVecs[I].ElmSize * IOVecs[I].NumElm, SEEK_CUR) == -1)
109         return 1;
110     }
111   }
112   return 0;
113 }
114 
initFileWriter(ProfDataWriter * This,FILE * File)115 static void initFileWriter(ProfDataWriter *This, FILE *File) {
116   This->Write = fileWriter;
117   This->WriterCtx = File;
118 }
119 
120 COMPILER_RT_VISIBILITY ProfBufferIO *
lprofCreateBufferIOInternal(void * File,uint32_t BufferSz)121 lprofCreateBufferIOInternal(void *File, uint32_t BufferSz) {
122   FreeHook = &free;
123   DynamicBufferIOBuffer = (uint8_t *)calloc(BufferSz, 1);
124   VPBufferSize = BufferSz;
125   ProfDataWriter *fileWriter =
126       (ProfDataWriter *)calloc(sizeof(ProfDataWriter), 1);
127   initFileWriter(fileWriter, File);
128   ProfBufferIO *IO = lprofCreateBufferIO(fileWriter);
129   IO->OwnFileWriter = 1;
130   return IO;
131 }
132 
setupIOBuffer()133 static void setupIOBuffer() {
134   const char *BufferSzStr = 0;
135   BufferSzStr = getenv("LLVM_VP_BUFFER_SIZE");
136   if (BufferSzStr && BufferSzStr[0]) {
137     VPBufferSize = atoi(BufferSzStr);
138     DynamicBufferIOBuffer = (uint8_t *)calloc(VPBufferSize, 1);
139   }
140 }
141 
142 /* Read profile data in \c ProfileFile and merge with in-memory
143    profile counters. Returns -1 if there is fatal error, otheriwse
144    0 is returned. Returning 0 does not mean merge is actually
145    performed. If merge is actually done, *MergeDone is set to 1.
146 */
doProfileMerging(FILE * ProfileFile,int * MergeDone)147 static int doProfileMerging(FILE *ProfileFile, int *MergeDone) {
148   uint64_t ProfileFileSize;
149   char *ProfileBuffer;
150 
151   if (fseek(ProfileFile, 0L, SEEK_END) == -1) {
152     PROF_ERR("Unable to merge profile data, unable to get size: %s\n",
153              strerror(errno));
154     return -1;
155   }
156   ProfileFileSize = ftell(ProfileFile);
157 
158   /* Restore file offset.  */
159   if (fseek(ProfileFile, 0L, SEEK_SET) == -1) {
160     PROF_ERR("Unable to merge profile data, unable to rewind: %s\n",
161              strerror(errno));
162     return -1;
163   }
164 
165   /* Nothing to merge.  */
166   if (ProfileFileSize < sizeof(__llvm_profile_header)) {
167     if (ProfileFileSize)
168       PROF_WARN("Unable to merge profile data: %s\n",
169                 "source profile file is too small.");
170     return 0;
171   }
172 
173   ProfileBuffer = mmap(NULL, ProfileFileSize, PROT_READ, MAP_SHARED | MAP_FILE,
174                        fileno(ProfileFile), 0);
175   if (ProfileBuffer == MAP_FAILED) {
176     PROF_ERR("Unable to merge profile data, mmap failed: %s\n",
177              strerror(errno));
178     return -1;
179   }
180 
181   if (__llvm_profile_check_compatibility(ProfileBuffer, ProfileFileSize)) {
182     (void)munmap(ProfileBuffer, ProfileFileSize);
183     PROF_WARN("Unable to merge profile data: %s\n",
184               "source profile file is not compatible.");
185     return 0;
186   }
187 
188   /* Now start merging */
189   __llvm_profile_merge_from_buffer(ProfileBuffer, ProfileFileSize);
190 
191   // Truncate the file in case merging of value profile did not happend to
192   // prevent from leaving garbage data at the end of the profile file.
193   COMPILER_RT_FTRUNCATE(ProfileFile, __llvm_profile_get_size_for_buffer());
194 
195   (void)munmap(ProfileBuffer, ProfileFileSize);
196   *MergeDone = 1;
197 
198   return 0;
199 }
200 
201 /* Create the directory holding the file, if needed. */
createProfileDir(const char * Filename)202 static void createProfileDir(const char *Filename) {
203   size_t Length = strlen(Filename);
204   if (lprofFindFirstDirSeparator(Filename)) {
205     char *Copy = (char *)COMPILER_RT_ALLOCA(Length + 1);
206     strncpy(Copy, Filename, Length + 1);
207     __llvm_profile_recursive_mkdir(Copy);
208   }
209 }
210 
211 /* Open the profile data for merging. It opens the file in r+b mode with
212  * file locking.  If the file has content which is compatible with the
213  * current process, it also reads in the profile data in the file and merge
214  * it with in-memory counters. After the profile data is merged in memory,
215  * the original profile data is truncated and gets ready for the profile
216  * dumper. With profile merging enabled, each executable as well as any of
217  * its instrumented shared libraries dump profile data into their own data file.
218 */
openFileForMerging(const char * ProfileFileName,int * MergeDone)219 static FILE *openFileForMerging(const char *ProfileFileName, int *MergeDone) {
220   FILE *ProfileFile;
221   int rc;
222 
223   createProfileDir(ProfileFileName);
224   ProfileFile = lprofOpenFileEx(ProfileFileName);
225   if (!ProfileFile)
226     return NULL;
227 
228   rc = doProfileMerging(ProfileFile, MergeDone);
229   if (rc || (!*MergeDone && COMPILER_RT_FTRUNCATE(ProfileFile, 0L)) ||
230       fseek(ProfileFile, 0L, SEEK_SET) == -1) {
231     PROF_ERR("Profile Merging of file %s failed: %s\n", ProfileFileName,
232              strerror(errno));
233     fclose(ProfileFile);
234     return NULL;
235   }
236   return ProfileFile;
237 }
238 
239 /* Write profile data to file \c OutputName.  */
writeFile(const char * OutputName)240 static int writeFile(const char *OutputName) {
241   int RetVal;
242   FILE *OutputFile;
243 
244   int MergeDone = 0;
245   VPMergeHook = &lprofMergeValueProfData;
246   if (!doMerging())
247     OutputFile = fopen(OutputName, "ab");
248   else
249     OutputFile = openFileForMerging(OutputName, &MergeDone);
250 
251   if (!OutputFile)
252     return -1;
253 
254   FreeHook = &free;
255   setupIOBuffer();
256   ProfDataWriter fileWriter;
257   initFileWriter(&fileWriter, OutputFile);
258   RetVal = lprofWriteData(&fileWriter, lprofGetVPDataReader(), MergeDone);
259 
260   fclose(OutputFile);
261   return RetVal;
262 }
263 
truncateCurrentFile(void)264 static void truncateCurrentFile(void) {
265   const char *Filename;
266   char *FilenameBuf;
267   FILE *File;
268   int Length;
269 
270   Length = getCurFilenameLength();
271   FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
272   Filename = getCurFilename(FilenameBuf, 0);
273   if (!Filename)
274     return;
275 
276   /* By pass file truncation to allow online raw profile
277    * merging. */
278   if (lprofCurFilename.MergePoolSize)
279     return;
280 
281   createProfileDir(Filename);
282 
283   /* Truncate the file.  Later we'll reopen and append. */
284   File = fopen(Filename, "w");
285   if (!File)
286     return;
287   fclose(File);
288 }
289 
290 static const char *DefaultProfileName = "default.profraw";
resetFilenameToDefault(void)291 static void resetFilenameToDefault(void) {
292   if (lprofCurFilename.FilenamePat && lprofCurFilename.OwnsFilenamePat) {
293     free((void *)lprofCurFilename.FilenamePat);
294   }
295   memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
296   lprofCurFilename.FilenamePat = DefaultProfileName;
297   lprofCurFilename.PNS = PNS_default;
298 }
299 
containsMergeSpecifier(const char * FilenamePat,int I)300 static int containsMergeSpecifier(const char *FilenamePat, int I) {
301   return (FilenamePat[I] == 'm' ||
302           (FilenamePat[I] >= '1' && FilenamePat[I] <= '9' &&
303            /* If FilenamePat[I] is not '\0', the next byte is guaranteed
304             * to be in-bound as the string is null terminated. */
305            FilenamePat[I + 1] == 'm'));
306 }
307 
308 /* Parses the pattern string \p FilenamePat and stores the result to
309  * lprofcurFilename structure. */
parseFilenamePattern(const char * FilenamePat,unsigned CopyFilenamePat)310 static int parseFilenamePattern(const char *FilenamePat,
311                                 unsigned CopyFilenamePat) {
312   int NumPids = 0, NumHosts = 0, I;
313   char *PidChars = &lprofCurFilename.PidChars[0];
314   char *Hostname = &lprofCurFilename.Hostname[0];
315   int MergingEnabled = 0;
316 
317   /* Clean up cached prefix and filename.  */
318   if (lprofCurFilename.ProfilePathPrefix)
319     free((void *)lprofCurFilename.ProfilePathPrefix);
320   if (lprofCurFilename.Filename)
321     free((void *)lprofCurFilename.Filename);
322 
323   if (lprofCurFilename.FilenamePat && lprofCurFilename.OwnsFilenamePat) {
324     free((void *)lprofCurFilename.FilenamePat);
325   }
326 
327   memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
328 
329   if (!CopyFilenamePat)
330     lprofCurFilename.FilenamePat = FilenamePat;
331   else {
332     lprofCurFilename.FilenamePat = strdup(FilenamePat);
333     lprofCurFilename.OwnsFilenamePat = 1;
334   }
335   /* Check the filename for "%p", which indicates a pid-substitution. */
336   for (I = 0; FilenamePat[I]; ++I)
337     if (FilenamePat[I] == '%') {
338       if (FilenamePat[++I] == 'p') {
339         if (!NumPids++) {
340           if (snprintf(PidChars, MAX_PID_SIZE, "%ld", (long)getpid()) <= 0) {
341             PROF_WARN("Unable to get pid for filename pattern %s. Using the "
342                       "default name.",
343                       FilenamePat);
344             return -1;
345           }
346         }
347       } else if (FilenamePat[I] == 'h') {
348         if (!NumHosts++)
349           if (COMPILER_RT_GETHOSTNAME(Hostname, COMPILER_RT_MAX_HOSTLEN)) {
350             PROF_WARN("Unable to get hostname for filename pattern %s. Using "
351                       "the default name.",
352                       FilenamePat);
353             return -1;
354           }
355       } else if (containsMergeSpecifier(FilenamePat, I)) {
356         if (MergingEnabled) {
357           PROF_WARN("%%m specifier can only be specified once in %s.\n",
358                     FilenamePat);
359           return -1;
360         }
361         MergingEnabled = 1;
362         if (FilenamePat[I] == 'm')
363           lprofCurFilename.MergePoolSize = 1;
364         else {
365           lprofCurFilename.MergePoolSize = FilenamePat[I] - '0';
366           I++; /* advance to 'm' */
367         }
368       }
369     }
370 
371   lprofCurFilename.NumPids = NumPids;
372   lprofCurFilename.NumHosts = NumHosts;
373   return 0;
374 }
375 
parseAndSetFilename(const char * FilenamePat,ProfileNameSpecifier PNS,unsigned CopyFilenamePat)376 static void parseAndSetFilename(const char *FilenamePat,
377                                 ProfileNameSpecifier PNS,
378                                 unsigned CopyFilenamePat) {
379 
380   const char *OldFilenamePat = lprofCurFilename.FilenamePat;
381   ProfileNameSpecifier OldPNS = lprofCurFilename.PNS;
382 
383   if (PNS < OldPNS)
384     return;
385 
386   if (!FilenamePat)
387     FilenamePat = DefaultProfileName;
388 
389   if (OldFilenamePat && !strcmp(OldFilenamePat, FilenamePat)) {
390     lprofCurFilename.PNS = PNS;
391     return;
392   }
393 
394   /* When PNS >= OldPNS, the last one wins. */
395   if (!FilenamePat || parseFilenamePattern(FilenamePat, CopyFilenamePat))
396     resetFilenameToDefault();
397   lprofCurFilename.PNS = PNS;
398 
399   if (!OldFilenamePat) {
400     if (getenv("LLVM_PROFILE_VERBOSE"))
401       PROF_NOTE("Set profile file path to \"%s\" via %s.\n",
402                 lprofCurFilename.FilenamePat, getPNSStr(PNS));
403   } else {
404     if (getenv("LLVM_PROFILE_VERBOSE"))
405       PROF_NOTE("Override old profile path \"%s\" via %s to \"%s\" via %s.\n",
406                 OldFilenamePat, getPNSStr(OldPNS), lprofCurFilename.FilenamePat,
407                 getPNSStr(PNS));
408   }
409 
410   truncateCurrentFile();
411 }
412 
413 /* Return buffer length that is required to store the current profile
414  * filename with PID and hostname substitutions. */
415 /* The length to hold uint64_t followed by 2 digit pool id including '_' */
416 #define SIGLEN 24
getCurFilenameLength()417 static int getCurFilenameLength() {
418   int Len;
419   if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
420     return 0;
421 
422   if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
423         lprofCurFilename.MergePoolSize))
424     return strlen(lprofCurFilename.FilenamePat);
425 
426   Len = strlen(lprofCurFilename.FilenamePat) +
427         lprofCurFilename.NumPids * (strlen(lprofCurFilename.PidChars) - 2) +
428         lprofCurFilename.NumHosts * (strlen(lprofCurFilename.Hostname) - 2);
429   if (lprofCurFilename.MergePoolSize)
430     Len += SIGLEN;
431   return Len;
432 }
433 
434 /* Return the pointer to the current profile file name (after substituting
435  * PIDs and Hostnames in filename pattern. \p FilenameBuf is the buffer
436  * to store the resulting filename. If no substitution is needed, the
437  * current filename pattern string is directly returned, unless ForceUseBuf
438  * is enabled. */
getCurFilename(char * FilenameBuf,int ForceUseBuf)439 static const char *getCurFilename(char *FilenameBuf, int ForceUseBuf) {
440   int I, J, PidLength, HostNameLength, FilenamePatLength;
441   const char *FilenamePat = lprofCurFilename.FilenamePat;
442 
443   if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
444     return 0;
445 
446   if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
447         lprofCurFilename.MergePoolSize)) {
448     if (!ForceUseBuf)
449       return lprofCurFilename.FilenamePat;
450 
451     FilenamePatLength = strlen(lprofCurFilename.FilenamePat);
452     memcpy(FilenameBuf, lprofCurFilename.FilenamePat, FilenamePatLength);
453     FilenameBuf[FilenamePatLength] = '\0';
454     return FilenameBuf;
455   }
456 
457   PidLength = strlen(lprofCurFilename.PidChars);
458   HostNameLength = strlen(lprofCurFilename.Hostname);
459   /* Construct the new filename. */
460   for (I = 0, J = 0; FilenamePat[I]; ++I)
461     if (FilenamePat[I] == '%') {
462       if (FilenamePat[++I] == 'p') {
463         memcpy(FilenameBuf + J, lprofCurFilename.PidChars, PidLength);
464         J += PidLength;
465       } else if (FilenamePat[I] == 'h') {
466         memcpy(FilenameBuf + J, lprofCurFilename.Hostname, HostNameLength);
467         J += HostNameLength;
468       } else if (containsMergeSpecifier(FilenamePat, I)) {
469         char LoadModuleSignature[SIGLEN];
470         int S;
471         int ProfilePoolId = getpid() % lprofCurFilename.MergePoolSize;
472         S = snprintf(LoadModuleSignature, SIGLEN, "%" PRIu64 "_%d",
473                      lprofGetLoadModuleSignature(), ProfilePoolId);
474         if (S == -1 || S > SIGLEN)
475           S = SIGLEN;
476         memcpy(FilenameBuf + J, LoadModuleSignature, S);
477         J += S;
478         if (FilenamePat[I] != 'm')
479           I++;
480       }
481       /* Drop any unknown substitutions. */
482     } else
483       FilenameBuf[J++] = FilenamePat[I];
484   FilenameBuf[J] = 0;
485 
486   return FilenameBuf;
487 }
488 
489 /* Returns the pointer to the environment variable
490  * string. Returns null if the env var is not set. */
getFilenamePatFromEnv(void)491 static const char *getFilenamePatFromEnv(void) {
492   const char *Filename = getenv("LLVM_PROFILE_FILE");
493   if (!Filename || !Filename[0])
494     return 0;
495   return Filename;
496 }
497 
498 COMPILER_RT_VISIBILITY
__llvm_profile_get_path_prefix(void)499 const char *__llvm_profile_get_path_prefix(void) {
500   int Length;
501   char *FilenameBuf, *Prefix;
502   const char *Filename, *PrefixEnd;
503 
504   if (lprofCurFilename.ProfilePathPrefix)
505     return lprofCurFilename.ProfilePathPrefix;
506 
507   Length = getCurFilenameLength();
508   FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
509   Filename = getCurFilename(FilenameBuf, 0);
510   if (!Filename)
511     return "\0";
512 
513   PrefixEnd = lprofFindLastDirSeparator(Filename);
514   if (!PrefixEnd)
515     return "\0";
516 
517   Length = PrefixEnd - Filename + 1;
518   Prefix = (char *)malloc(Length + 1);
519   if (!Prefix) {
520     PROF_ERR("Failed to %s\n", "allocate memory.");
521     return "\0";
522   }
523   memcpy(Prefix, Filename, Length);
524   Prefix[Length] = '\0';
525   lprofCurFilename.ProfilePathPrefix = Prefix;
526   return Prefix;
527 }
528 
529 COMPILER_RT_VISIBILITY
__llvm_profile_get_filename(void)530 const char *__llvm_profile_get_filename(void) {
531   int Length;
532   char *FilenameBuf;
533   const char *Filename;
534 
535   if (lprofCurFilename.Filename)
536     return lprofCurFilename.Filename;
537 
538   Length = getCurFilenameLength();
539   FilenameBuf = (char *)malloc(Length + 1);
540   if (!FilenameBuf) {
541     PROF_ERR("Failed to %s\n", "allocate memory.");
542     return "\0";
543   }
544   Filename = getCurFilename(FilenameBuf, 1);
545   if (!Filename)
546     return "\0";
547 
548   lprofCurFilename.Filename = FilenameBuf;
549   return FilenameBuf;
550 }
551 
552 /* This method is invoked by the runtime initialization hook
553  * InstrProfilingRuntime.o if it is linked in. Both user specified
554  * profile path via -fprofile-instr-generate= and LLVM_PROFILE_FILE
555  * environment variable can override this default value. */
556 COMPILER_RT_VISIBILITY
__llvm_profile_initialize_file(void)557 void __llvm_profile_initialize_file(void) {
558   const char *EnvFilenamePat;
559   const char *SelectedPat = NULL;
560   ProfileNameSpecifier PNS = PNS_unknown;
561   int hasCommandLineOverrider = (INSTR_PROF_PROFILE_NAME_VAR[0] != 0);
562 
563   EnvFilenamePat = getFilenamePatFromEnv();
564   if (EnvFilenamePat) {
565     /* Pass CopyFilenamePat = 1, to ensure that the filename would be valid
566        at the  moment when __llvm_profile_write_file() gets executed. */
567     parseAndSetFilename(EnvFilenamePat, PNS_environment, 1);
568     return;
569   } else if (hasCommandLineOverrider) {
570     SelectedPat = INSTR_PROF_PROFILE_NAME_VAR;
571     PNS = PNS_command_line;
572   } else {
573     SelectedPat = NULL;
574     PNS = PNS_default;
575   }
576 
577   parseAndSetFilename(SelectedPat, PNS, 0);
578 }
579 
580 /* This API is directly called by the user application code. It has the
581  * highest precedence compared with LLVM_PROFILE_FILE environment variable
582  * and command line option -fprofile-instr-generate=<profile_name>.
583  */
584 COMPILER_RT_VISIBILITY
__llvm_profile_set_filename(const char * FilenamePat)585 void __llvm_profile_set_filename(const char *FilenamePat) {
586   parseAndSetFilename(FilenamePat, PNS_runtime_api, 1);
587 }
588 
589 /* The public API for writing profile data into the file with name
590  * set by previous calls to __llvm_profile_set_filename or
591  * __llvm_profile_override_default_filename or
592  * __llvm_profile_initialize_file. */
593 COMPILER_RT_VISIBILITY
__llvm_profile_write_file(void)594 int __llvm_profile_write_file(void) {
595   int rc, Length;
596   const char *Filename;
597   char *FilenameBuf;
598   int PDeathSig = 0;
599 
600   if (lprofProfileDumped()) {
601     PROF_NOTE("Profile data not written to file: %s.\n",
602               "already written");
603     return 0;
604   }
605 
606   Length = getCurFilenameLength();
607   FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
608   Filename = getCurFilename(FilenameBuf, 0);
609 
610   /* Check the filename. */
611   if (!Filename) {
612     PROF_ERR("Failed to write file : %s\n", "Filename not set");
613     return -1;
614   }
615 
616   /* Check if there is llvm/runtime version mismatch.  */
617   if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {
618     PROF_ERR("Runtime and instrumentation version mismatch : "
619              "expected %d, but get %d\n",
620              INSTR_PROF_RAW_VERSION,
621              (int)GET_VERSION(__llvm_profile_get_version()));
622     return -1;
623   }
624 
625   // Temporarily suspend getting SIGKILL when the parent exits.
626   PDeathSig = lprofSuspendSigKill();
627 
628   /* Write profile data to the file. */
629   rc = writeFile(Filename);
630   if (rc)
631     PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno));
632 
633   // Restore SIGKILL.
634   if (PDeathSig == 1)
635     lprofRestoreSigKill();
636 
637   return rc;
638 }
639 
640 COMPILER_RT_VISIBILITY
__llvm_profile_dump(void)641 int __llvm_profile_dump(void) {
642   if (!doMerging())
643     PROF_WARN("Later invocation of __llvm_profile_dump can lead to clobbering "
644               " of previously dumped profile data : %s. Either use %%m "
645               "in profile name or change profile name before dumping.\n",
646               "online profile merging is not on");
647   int rc = __llvm_profile_write_file();
648   lprofSetProfileDumped();
649   return rc;
650 }
651 
writeFileWithoutReturn(void)652 static void writeFileWithoutReturn(void) { __llvm_profile_write_file(); }
653 
654 COMPILER_RT_VISIBILITY
__llvm_profile_register_write_file_atexit(void)655 int __llvm_profile_register_write_file_atexit(void) {
656   static int HasBeenRegistered = 0;
657 
658   if (HasBeenRegistered)
659     return 0;
660 
661   lprofSetupValueProfiler();
662 
663   HasBeenRegistered = 1;
664   return atexit(writeFileWithoutReturn);
665 }
666 
667 #endif
668