llvm-project/compiler-rt/lib/profile/InstrProfilingFile.c

623 lines
19 KiB
C

/*===- InstrProfilingFile.c - Write instrumentation to a file -------------===*\
|*
|* The LLVM Compiler Infrastructure
|*
|* This file is distributed under the University of Illinois Open Source
|* License. See LICENSE.TXT for details.
|*
\*===----------------------------------------------------------------------===*/
#include "InstrProfiling.h"
#include "InstrProfilingInternal.h"
#include "InstrProfilingUtil.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _MSC_VER
/* For _alloca. */
#include <malloc.h>
#endif
#if defined(_WIN32)
#include "WindowsMMap.h"
/* For _chsize_s */
#include <io.h>
#else
#include <sys/file.h>
#include <sys/mman.h>
#include <unistd.h>
#if defined(__linux__)
#include <sys/types.h>
#endif
#endif
/* From where is profile name specified.
* The order the enumerators define their
* precedence. Re-order them may lead to
* runtime behavior change. */
typedef enum ProfileNameSpecifier {
PNS_unknown = 0,
PNS_default,
PNS_command_line,
PNS_environment,
PNS_runtime_api
} ProfileNameSpecifier;
static const char *getPNSStr(ProfileNameSpecifier PNS) {
switch (PNS) {
case PNS_default:
return "default setting";
case PNS_command_line:
return "command line";
case PNS_environment:
return "environment variable";
case PNS_runtime_api:
return "runtime API";
default:
return "Unknown";
}
}
#define MAX_PID_SIZE 16
/* Data structure holding the result of parsed filename pattern. */
typedef struct lprofFilename {
/* File name string possibly with %p or %h specifiers. */
const char *FilenamePat;
/* A flag indicating if FilenamePat's memory is allocated
* by runtime. */
unsigned OwnsFilenamePat;
const char *ProfilePathPrefix;
char PidChars[MAX_PID_SIZE];
char Hostname[COMPILER_RT_MAX_HOSTLEN];
unsigned NumPids;
unsigned NumHosts;
/* When in-process merging is enabled, this parameter specifies
* the total number of profile data files shared by all the processes
* spawned from the same binary. By default the value is 1. If merging
* is not enabled, its value should be 0. This parameter is specified
* by the %[0-9]m specifier. For instance %2m enables merging using
* 2 profile data files. %1m is equivalent to %m. Also %m specifier
* can only appear once at the end of the name pattern. */
unsigned MergePoolSize;
ProfileNameSpecifier PNS;
} lprofFilename;
COMPILER_RT_WEAK lprofFilename lprofCurFilename = {0, 0, 0, {0}, {0},
0, 0, 0, PNS_unknown};
int getpid(void);
static int getCurFilenameLength(void);
static const char *getCurFilename(char *FilenameBuf);
static unsigned doMerging() { return lprofCurFilename.MergePoolSize; }
/* Return 1 if there is an error, otherwise return 0. */
static uint32_t fileWriter(ProfDataWriter *This, ProfDataIOVec *IOVecs,
uint32_t NumIOVecs) {
uint32_t I;
FILE *File = (FILE *)This->WriterCtx;
for (I = 0; I < NumIOVecs; I++) {
if (IOVecs[I].Data) {
if (fwrite(IOVecs[I].Data, IOVecs[I].ElmSize, IOVecs[I].NumElm, File) !=
IOVecs[I].NumElm)
return 1;
} else {
if (fseek(File, IOVecs[I].ElmSize * IOVecs[I].NumElm, SEEK_CUR) == -1)
return 1;
}
}
return 0;
}
static void initFileWriter(ProfDataWriter *This, FILE *File) {
This->Write = fileWriter;
This->WriterCtx = File;
}
COMPILER_RT_VISIBILITY ProfBufferIO *
lprofCreateBufferIOInternal(void *File, uint32_t BufferSz) {
FreeHook = &free;
DynamicBufferIOBuffer = (uint8_t *)calloc(BufferSz, 1);
VPBufferSize = BufferSz;
ProfDataWriter *fileWriter =
(ProfDataWriter *)calloc(sizeof(ProfDataWriter), 1);
initFileWriter(fileWriter, File);
ProfBufferIO *IO = lprofCreateBufferIO(fileWriter);
IO->OwnFileWriter = 1;
return IO;
}
static void setupIOBuffer() {
const char *BufferSzStr = 0;
BufferSzStr = getenv("LLVM_VP_BUFFER_SIZE");
if (BufferSzStr && BufferSzStr[0]) {
VPBufferSize = atoi(BufferSzStr);
DynamicBufferIOBuffer = (uint8_t *)calloc(VPBufferSize, 1);
}
}
/* Read profile data in \c ProfileFile and merge with in-memory
profile counters. Returns -1 if there is fatal error, otheriwse
0 is returned. Returning 0 does not mean merge is actually
performed. If merge is actually done, *MergeDone is set to 1.
*/
static int doProfileMerging(FILE *ProfileFile, int *MergeDone) {
uint64_t ProfileFileSize;
char *ProfileBuffer;
if (fseek(ProfileFile, 0L, SEEK_END) == -1) {
PROF_ERR("Unable to merge profile data, unable to get size: %s\n",
strerror(errno));
return -1;
}
ProfileFileSize = ftell(ProfileFile);
/* Restore file offset. */
if (fseek(ProfileFile, 0L, SEEK_SET) == -1) {
PROF_ERR("Unable to merge profile data, unable to rewind: %s\n",
strerror(errno));
return -1;
}
/* Nothing to merge. */
if (ProfileFileSize < sizeof(__llvm_profile_header)) {
if (ProfileFileSize)
PROF_WARN("Unable to merge profile data: %s\n",
"source profile file is too small.");
return 0;
}
ProfileBuffer = mmap(NULL, ProfileFileSize, PROT_READ, MAP_SHARED | MAP_FILE,
fileno(ProfileFile), 0);
if (ProfileBuffer == MAP_FAILED) {
PROF_ERR("Unable to merge profile data, mmap failed: %s\n",
strerror(errno));
return -1;
}
if (__llvm_profile_check_compatibility(ProfileBuffer, ProfileFileSize)) {
(void)munmap(ProfileBuffer, ProfileFileSize);
PROF_WARN("Unable to merge profile data: %s\n",
"source profile file is not compatible.");
return 0;
}
/* Now start merging */
__llvm_profile_merge_from_buffer(ProfileBuffer, ProfileFileSize);
(void)munmap(ProfileBuffer, ProfileFileSize);
*MergeDone = 1;
return 0;
}
/* Create the directory holding the file, if needed. */
static void createProfileDir(const char *Filename) {
size_t Length = strlen(Filename);
if (lprofFindFirstDirSeparator(Filename)) {
char *Copy = (char *)COMPILER_RT_ALLOCA(Length + 1);
strncpy(Copy, Filename, Length + 1);
__llvm_profile_recursive_mkdir(Copy);
}
}
/* Open the profile data for merging. It opens the file in r+b mode with
* file locking. If the file has content which is compatible with the
* current process, it also reads in the profile data in the file and merge
* it with in-memory counters. After the profile data is merged in memory,
* the original profile data is truncated and gets ready for the profile
* dumper. With profile merging enabled, each executable as well as any of
* its instrumented shared libraries dump profile data into their own data file.
*/
static FILE *openFileForMerging(const char *ProfileFileName, int *MergeDone) {
FILE *ProfileFile;
int rc;
createProfileDir(ProfileFileName);
ProfileFile = lprofOpenFileEx(ProfileFileName);
if (!ProfileFile)
return NULL;
rc = doProfileMerging(ProfileFile, MergeDone);
if (rc || (!*MergeDone && COMPILER_RT_FTRUNCATE(ProfileFile, 0L)) ||
fseek(ProfileFile, 0L, SEEK_SET) == -1) {
PROF_ERR("Profile Merging of file %s failed: %s\n", ProfileFileName,
strerror(errno));
fclose(ProfileFile);
return NULL;
}
return ProfileFile;
}
/* Write profile data to file \c OutputName. */
static int writeFile(const char *OutputName) {
int RetVal;
FILE *OutputFile;
int MergeDone = 0;
if (!doMerging())
OutputFile = fopen(OutputName, "ab");
else
OutputFile = openFileForMerging(OutputName, &MergeDone);
if (!OutputFile)
return -1;
FreeHook = &free;
setupIOBuffer();
ProfDataWriter fileWriter;
initFileWriter(&fileWriter, OutputFile);
RetVal = lprofWriteData(&fileWriter, lprofGetVPDataReader(), MergeDone);
fclose(OutputFile);
return RetVal;
}
static void truncateCurrentFile(void) {
const char *Filename;
char *FilenameBuf;
FILE *File;
int Length;
Length = getCurFilenameLength();
FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
Filename = getCurFilename(FilenameBuf);
if (!Filename)
return;
/* By pass file truncation to allow online raw profile
* merging. */
if (lprofCurFilename.MergePoolSize)
return;
createProfileDir(Filename);
/* Truncate the file. Later we'll reopen and append. */
File = fopen(Filename, "w");
if (!File)
return;
fclose(File);
}
static const char *DefaultProfileName = "default.profraw";
static void resetFilenameToDefault(void) {
if (lprofCurFilename.FilenamePat && lprofCurFilename.OwnsFilenamePat) {
free((void *)lprofCurFilename.FilenamePat);
}
memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
lprofCurFilename.FilenamePat = DefaultProfileName;
lprofCurFilename.PNS = PNS_default;
}
static int containsMergeSpecifier(const char *FilenamePat, int I) {
return (FilenamePat[I] == 'm' ||
(FilenamePat[I] >= '1' && FilenamePat[I] <= '9' &&
/* If FilenamePat[I] is not '\0', the next byte is guaranteed
* to be in-bound as the string is null terminated. */
FilenamePat[I + 1] == 'm'));
}
/* Parses the pattern string \p FilenamePat and stores the result to
* lprofcurFilename structure. */
static int parseFilenamePattern(const char *FilenamePat,
unsigned CopyFilenamePat) {
int NumPids = 0, NumHosts = 0, I;
char *PidChars = &lprofCurFilename.PidChars[0];
char *Hostname = &lprofCurFilename.Hostname[0];
int MergingEnabled = 0;
/* Clean up cached prefix. */
if (lprofCurFilename.ProfilePathPrefix)
free((void *)lprofCurFilename.ProfilePathPrefix);
memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
if (lprofCurFilename.FilenamePat && lprofCurFilename.OwnsFilenamePat) {
free((void *)lprofCurFilename.FilenamePat);
}
if (!CopyFilenamePat)
lprofCurFilename.FilenamePat = FilenamePat;
else {
lprofCurFilename.FilenamePat = strdup(FilenamePat);
lprofCurFilename.OwnsFilenamePat = 1;
}
/* Check the filename for "%p", which indicates a pid-substitution. */
for (I = 0; FilenamePat[I]; ++I)
if (FilenamePat[I] == '%') {
if (FilenamePat[++I] == 'p') {
if (!NumPids++) {
if (snprintf(PidChars, MAX_PID_SIZE, "%d", getpid()) <= 0) {
PROF_WARN("Unable to get pid for filename pattern %s. Using the "
"default name.",
FilenamePat);
return -1;
}
}
} else if (FilenamePat[I] == 'h') {
if (!NumHosts++)
if (COMPILER_RT_GETHOSTNAME(Hostname, COMPILER_RT_MAX_HOSTLEN)) {
PROF_WARN("Unable to get hostname for filename pattern %s. Using "
"the default name.",
FilenamePat);
return -1;
}
} else if (containsMergeSpecifier(FilenamePat, I)) {
if (MergingEnabled) {
PROF_WARN("%%m specifier can only be specified once in %s.\n",
FilenamePat);
return -1;
}
MergingEnabled = 1;
if (FilenamePat[I] == 'm')
lprofCurFilename.MergePoolSize = 1;
else {
lprofCurFilename.MergePoolSize = FilenamePat[I] - '0';
I++; /* advance to 'm' */
}
}
}
lprofCurFilename.NumPids = NumPids;
lprofCurFilename.NumHosts = NumHosts;
return 0;
}
static void parseAndSetFilename(const char *FilenamePat,
ProfileNameSpecifier PNS,
unsigned CopyFilenamePat) {
const char *OldFilenamePat = lprofCurFilename.FilenamePat;
ProfileNameSpecifier OldPNS = lprofCurFilename.PNS;
if (PNS < OldPNS)
return;
if (!FilenamePat)
FilenamePat = DefaultProfileName;
if (OldFilenamePat && !strcmp(OldFilenamePat, FilenamePat)) {
lprofCurFilename.PNS = PNS;
return;
}
/* When PNS >= OldPNS, the last one wins. */
if (!FilenamePat || parseFilenamePattern(FilenamePat, CopyFilenamePat))
resetFilenameToDefault();
lprofCurFilename.PNS = PNS;
if (!OldFilenamePat) {
if (getenv("LLVM_PROFILE_VERBOSE"))
PROF_NOTE("Set profile file path to \"%s\" via %s.\n",
lprofCurFilename.FilenamePat, getPNSStr(PNS));
} else {
if (getenv("LLVM_PROFILE_VERBOSE"))
PROF_NOTE("Override old profile path \"%s\" via %s to \"%s\" via %s.\n",
OldFilenamePat, getPNSStr(OldPNS), lprofCurFilename.FilenamePat,
getPNSStr(PNS));
}
truncateCurrentFile();
}
/* Return buffer length that is required to store the current profile
* filename with PID and hostname substitutions. */
/* The length to hold uint64_t followed by 2 digit pool id including '_' */
#define SIGLEN 24
static int getCurFilenameLength() {
int Len;
if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
return 0;
if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
lprofCurFilename.MergePoolSize))
return strlen(lprofCurFilename.FilenamePat);
Len = strlen(lprofCurFilename.FilenamePat) +
lprofCurFilename.NumPids * (strlen(lprofCurFilename.PidChars) - 2) +
lprofCurFilename.NumHosts * (strlen(lprofCurFilename.Hostname) - 2);
if (lprofCurFilename.MergePoolSize)
Len += SIGLEN;
return Len;
}
/* Return the pointer to the current profile file name (after substituting
* PIDs and Hostnames in filename pattern. \p FilenameBuf is the buffer
* to store the resulting filename. If no substitution is needed, the
* current filename pattern string is directly returned. */
static const char *getCurFilename(char *FilenameBuf) {
int I, J, PidLength, HostNameLength;
const char *FilenamePat = lprofCurFilename.FilenamePat;
if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
return 0;
if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
lprofCurFilename.MergePoolSize))
return lprofCurFilename.FilenamePat;
PidLength = strlen(lprofCurFilename.PidChars);
HostNameLength = strlen(lprofCurFilename.Hostname);
/* Construct the new filename. */
for (I = 0, J = 0; FilenamePat[I]; ++I)
if (FilenamePat[I] == '%') {
if (FilenamePat[++I] == 'p') {
memcpy(FilenameBuf + J, lprofCurFilename.PidChars, PidLength);
J += PidLength;
} else if (FilenamePat[I] == 'h') {
memcpy(FilenameBuf + J, lprofCurFilename.Hostname, HostNameLength);
J += HostNameLength;
} else if (containsMergeSpecifier(FilenamePat, I)) {
char LoadModuleSignature[SIGLEN];
int S;
int ProfilePoolId = getpid() % lprofCurFilename.MergePoolSize;
S = snprintf(LoadModuleSignature, SIGLEN, "%" PRIu64 "_%d",
lprofGetLoadModuleSignature(), ProfilePoolId);
if (S == -1 || S > SIGLEN)
S = SIGLEN;
memcpy(FilenameBuf + J, LoadModuleSignature, S);
J += S;
if (FilenamePat[I] != 'm')
I++;
}
/* Drop any unknown substitutions. */
} else
FilenameBuf[J++] = FilenamePat[I];
FilenameBuf[J] = 0;
return FilenameBuf;
}
/* Returns the pointer to the environment variable
* string. Returns null if the env var is not set. */
static const char *getFilenamePatFromEnv(void) {
const char *Filename = getenv("LLVM_PROFILE_FILE");
if (!Filename || !Filename[0])
return 0;
return Filename;
}
COMPILER_RT_VISIBILITY
const char *__llvm_profile_get_path_prefix(void) {
int Length;
char *FilenameBuf, *Prefix;
const char *Filename, *PrefixEnd;
if (lprofCurFilename.ProfilePathPrefix)
return lprofCurFilename.ProfilePathPrefix;
Length = getCurFilenameLength();
FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
Filename = getCurFilename(FilenameBuf);
if (!Filename)
return "\0";
PrefixEnd = lprofFindLastDirSeparator(Filename);
if (!PrefixEnd)
return "\0";
Length = PrefixEnd - Filename + 1;
Prefix = (char *)malloc(Length + 1);
if (!Prefix) {
PROF_ERR("Failed to %s\n", "allocate memory.");
return "\0";
}
memcpy(Prefix, Filename, Length);
Prefix[Length] = '\0';
lprofCurFilename.ProfilePathPrefix = Prefix;
return Prefix;
}
/* This method is invoked by the runtime initialization hook
* InstrProfilingRuntime.o if it is linked in. Both user specified
* profile path via -fprofile-instr-generate= and LLVM_PROFILE_FILE
* environment variable can override this default value. */
COMPILER_RT_VISIBILITY
void __llvm_profile_initialize_file(void) {
const char *EnvFilenamePat;
const char *SelectedPat = NULL;
ProfileNameSpecifier PNS = PNS_unknown;
int hasCommandLineOverrider = (INSTR_PROF_PROFILE_NAME_VAR[0] != 0);
EnvFilenamePat = getFilenamePatFromEnv();
if (EnvFilenamePat) {
/* Pass CopyFilenamePat = 1, to ensure that the filename would be valid
at the moment when __llvm_profile_write_file() gets executed. */
parseAndSetFilename(EnvFilenamePat, PNS_environment, 1);
return;
} else if (hasCommandLineOverrider) {
SelectedPat = INSTR_PROF_PROFILE_NAME_VAR;
PNS = PNS_command_line;
} else {
SelectedPat = NULL;
PNS = PNS_default;
}
parseAndSetFilename(SelectedPat, PNS, 0);
}
/* This API is directly called by the user application code. It has the
* highest precedence compared with LLVM_PROFILE_FILE environment variable
* and command line option -fprofile-instr-generate=<profile_name>.
*/
COMPILER_RT_VISIBILITY
void __llvm_profile_set_filename(const char *FilenamePat) {
parseAndSetFilename(FilenamePat, PNS_runtime_api, 1);
}
/* The public API for writing profile data into the file with name
* set by previous calls to __llvm_profile_set_filename or
* __llvm_profile_override_default_filename or
* __llvm_profile_initialize_file. */
COMPILER_RT_VISIBILITY
int __llvm_profile_write_file(void) {
int rc, Length;
const char *Filename;
char *FilenameBuf;
int PDeathSig = 0;
if (lprofProfileDumped()) {
PROF_NOTE("Profile data not written to file: %s.\n",
"already written");
return 0;
}
Length = getCurFilenameLength();
FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
Filename = getCurFilename(FilenameBuf);
/* Check the filename. */
if (!Filename) {
PROF_ERR("Failed to write file : %s\n", "Filename not set");
return -1;
}
/* Check if there is llvm/runtime version mismatch. */
if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {
PROF_ERR("Runtime and instrumentation version mismatch : "
"expected %d, but get %d\n",
INSTR_PROF_RAW_VERSION,
(int)GET_VERSION(__llvm_profile_get_version()));
return -1;
}
// Temporarily suspend getting SIGKILL when the parent exits.
PDeathSig = lprofSuspendSigKill();
/* Write profile data to the file. */
rc = writeFile(Filename);
if (rc)
PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno));
// Restore SIGKILL.
if (PDeathSig == 1)
lprofRestoreSigKill();
return rc;
}
COMPILER_RT_VISIBILITY
int __llvm_profile_dump(void) {
if (!doMerging())
PROF_WARN("Later invocation of __llvm_profile_dump can lead to clobbering "
" of previously dumped profile data : %s. Either use %%m "
"in profile name or change profile name before dumping.\n",
"online profile merging is not on");
int rc = __llvm_profile_write_file();
lprofSetProfileDumped();
return rc;
}
static void writeFileWithoutReturn(void) { __llvm_profile_write_file(); }
COMPILER_RT_VISIBILITY
int __llvm_profile_register_write_file_atexit(void) {
static int HasBeenRegistered = 0;
if (HasBeenRegistered)
return 0;
lprofSetupValueProfiler();
HasBeenRegistered = 1;
return atexit(writeFileWithoutReturn);
}