1 /*===-- CommonProfiling.c - Profiling support library support -------------===*\ 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 |* This file implements functions used by the various different types of 11 |* profiling implementations. 12 |* 13 \*===----------------------------------------------------------------------===*/ 14 15 #include "Profiling.h" 16 #include <assert.h> 17 #include <sys/types.h> 18 #include <sys/stat.h> 19 #include <fcntl.h> 20 #include <stdio.h> 21 #include <string.h> 22 #if !defined(_MSC_VER) && !defined(__MINGW32__) 23 #include <unistd.h> 24 #else 25 #include <io.h> 26 #endif 27 #include <stdlib.h> 28 29 static char *SavedArgs = 0; 30 static unsigned SavedArgsLength = 0; 31 static const char *SavedEnvVar = 0; 32 33 static const char *OutputFilename = "llvmprof.out"; 34 35 /* check_environment_variable - Check to see if the LLVMPROF_OUTPUT environment 36 * variable is set. If it is then save it and set OutputFilename. 37 */ 38 static void check_environment_variable(void) { 39 const char *EnvVar; 40 if (SavedEnvVar) return; /* Guarantee that we can't leak memory. */ 41 42 if ((EnvVar = getenv("LLVMPROF_OUTPUT")) != NULL) { 43 /* The string that getenv returns is allowed to be statically allocated, 44 * which means it may be changed by future calls to getenv, so copy it. 45 */ 46 SavedEnvVar = strdup(EnvVar); 47 OutputFilename = SavedEnvVar; 48 } 49 } 50 51 /* save_arguments - Save argc and argv as passed into the program for the file 52 * we output. 53 * If either the LLVMPROF_OUTPUT environment variable or the -llvmprof-output 54 * command line argument are set then change OutputFilename to the provided 55 * value. The command line argument value overrides the environment variable. 56 */ 57 int save_arguments(int argc, const char **argv) { 58 unsigned Length, i; 59 if (!SavedEnvVar && !SavedArgs) check_environment_variable(); 60 if (SavedArgs || !argv) return argc; /* This can be called multiple times */ 61 62 /* Check to see if there are any arguments passed into the program for the 63 * profiler. If there are, strip them off and remember their settings. 64 */ 65 while (argc > 1 && !strncmp(argv[1], "-llvmprof-", 10)) { 66 /* Ok, we have an llvmprof argument. Remove it from the arg list and decide 67 * what to do with it. 68 */ 69 const char *Arg = argv[1]; 70 memmove((char**)&argv[1], &argv[2], (argc-1)*sizeof(char*)); 71 --argc; 72 73 if (!strcmp(Arg, "-llvmprof-output")) { 74 if (argc == 1) 75 puts("-llvmprof-output requires a filename argument!"); 76 else { 77 OutputFilename = strdup(argv[1]); 78 if (SavedEnvVar) { free((void *)SavedEnvVar); SavedEnvVar = 0; } 79 memmove((char**)&argv[1], &argv[2], (argc-1)*sizeof(char*)); 80 --argc; 81 } 82 } else { 83 printf("Unknown option to the profiler runtime: '%s' - ignored.\n", Arg); 84 } 85 } 86 87 for (Length = 0, i = 0; i != (unsigned)argc; ++i) 88 Length += strlen(argv[i])+1; 89 90 /* Defensively check for a zero length, even though this is unlikely 91 * to happen in practice. This avoids calling malloc() below with a 92 * size of 0. 93 */ 94 if (Length == 0) { 95 SavedArgs = 0; 96 SavedArgsLength = 0; 97 return argc; 98 } 99 100 SavedArgs = (char*)malloc(Length); 101 for (Length = 0, i = 0; i != (unsigned)argc; ++i) { 102 unsigned Len = strlen(argv[i]); 103 memcpy(SavedArgs+Length, argv[i], Len); 104 Length += Len; 105 SavedArgs[Length++] = ' '; 106 } 107 108 SavedArgsLength = Length; 109 110 return argc; 111 } 112 113 114 /* 115 * Retrieves the file descriptor for the profile file. 116 */ 117 int getOutFile() { 118 static int OutFile = -1; 119 120 /* If this is the first time this function is called, open the output file 121 * for appending, creating it if it does not already exist. 122 */ 123 if (OutFile == -1) { 124 OutFile = open(OutputFilename, O_CREAT | O_WRONLY, 0666); 125 lseek(OutFile, 0, SEEK_END); /* O_APPEND prevents seeking */ 126 if (OutFile == -1) { 127 fprintf(stderr, "LLVM profiling runtime: while opening '%s': ", 128 OutputFilename); 129 perror(""); 130 return(OutFile); 131 } 132 133 /* Output the command line arguments to the file. */ 134 { 135 int PTy = ArgumentInfo; 136 int Zeros = 0; 137 if (write(OutFile, &PTy, sizeof(int)) < 0 || 138 write(OutFile, &SavedArgsLength, sizeof(unsigned)) < 0 || 139 write(OutFile, SavedArgs, SavedArgsLength) < 0 ) { 140 fprintf(stderr,"error: unable to write to output file."); 141 exit(0); 142 } 143 /* Pad out to a multiple of four bytes */ 144 if (SavedArgsLength & 3) { 145 if (write(OutFile, &Zeros, 4-(SavedArgsLength&3)) < 0) { 146 fprintf(stderr,"error: unable to write to output file."); 147 exit(0); 148 } 149 } 150 } 151 } 152 return(OutFile); 153 } 154 155 /* write_profiling_data - Write a raw block of profiling counters out to the 156 * llvmprof.out file. Note that we allow programs to be instrumented with 157 * multiple different kinds of instrumentation. For this reason, this function 158 * may be called more than once. 159 */ 160 void write_profiling_data(enum ProfilingType PT, unsigned *Start, 161 unsigned NumElements) { 162 int PTy; 163 int outFile = getOutFile(); 164 165 /* Write out this record! */ 166 PTy = PT; 167 if( write(outFile, &PTy, sizeof(int)) < 0 || 168 write(outFile, &NumElements, sizeof(unsigned)) < 0 || 169 write(outFile, Start, NumElements*sizeof(unsigned)) < 0 ) { 170 fprintf(stderr,"error: unable to write to output file."); 171 exit(0); 172 } 173 } 174
