runtime/libprofile/CommonProfiling.c

   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 #include <unistd.h>
  23 #include <stdlib.h>
  24
  25 static char *SavedArgs = 0;
  26 static unsigned SavedArgsLength = 0;
  27
  28 static const char *OutputFilename = "llvmprof.out";
  29
  30 /* save_arguments - Save argc and argv as passed into the program for the file
  31  * we output.
  32  */
  33 int save_arguments(int argc, const char **argv) {
  34   unsigned Length, i;
  35   if (SavedArgs || !argv) return argc;  /* This can be called multiple times */
  36
  37   /* Check to see if there are any arguments passed into the program for the
  38    * profiler.  If there are, strip them off and remember their settings.
  39    */
  40   while (argc > 1 && !strncmp(argv[1], "-llvmprof-", 10)) {
  41     /* Ok, we have an llvmprof argument.  Remove it from the arg list and decide
  42      * what to do with it.
  43      */
  44     const char *Arg = argv[1];
  45     memmove(&argv[1], &argv[2], (argc-1)*sizeof(char*));
  46     --argc;
  47
  48     if (!strcmp(Arg, "-llvmprof-output")) {
  49       if (argc == 1)
  50         puts("-llvmprof-output requires a filename argument!");
  51       else {
  52         OutputFilename = strdup(argv[1]);
  53         memmove(&argv[1], &argv[2], (argc-1)*sizeof(char*));
  54         --argc;
  55       }
  56     } else {
  57       printf("Unknown option to the profiler runtime: '%s' - ignored.\n", Arg);
  58     }
  59   }
  60
  61   for (Length = 0, i = 0; i != (unsigned)argc; ++i)
  62     Length += strlen(argv[i])+1;
  63
  64   SavedArgs = (char*)malloc(Length);
  65   for (Length = 0, i = 0; i != (unsigned)argc; ++i) {
  66     unsigned Len = strlen(argv[i]);
  67     memcpy(SavedArgs+Length, argv[i], Len);
  68     Length += Len;
  69     SavedArgs[Length++] = ' ';
  70   }
  71
  72   SavedArgsLength = Length;
  73
  74   return argc;
  75 }
  76
  77
  78 /*
  79  * Retrieves the file descriptor for the profile file.
  80  */
  81 int getOutFile() {
  82   static int OutFile = -1;
  83
  84   /* If this is the first time this function is called, open the output file
  85    * for appending, creating it if it does not already exist.
  86    */
  87   if (OutFile == -1) {
  88     OutFile = open(OutputFilename, O_CREAT | O_WRONLY, 0666);
  89     lseek(OutFile, 0, SEEK_END); /* O_APPEND prevents seeking */
  90     if (OutFile == -1) {
  91       fprintf(stderr, "LLVM profiling runtime: while opening '%s': ",
  92               OutputFilename);
  93       perror("");
  94       return(OutFile);
  95     }
  96
  97     /* Output the command line arguments to the file. */
  98     {
  99       int PTy = ArgumentInfo;
 100       int Zeros = 0;
 101       write(OutFile, &PTy, sizeof(int));
 102       write(OutFile, &SavedArgsLength, sizeof(unsigned));
 103       write(OutFile, SavedArgs, SavedArgsLength);
 104       /* Pad out to a multiple of four bytes */
 105       if (SavedArgsLength & 3)
 106         write(OutFile, &Zeros, 4-(SavedArgsLength&3));
 107     }
 108   }
 109   return(OutFile);
 110 }
 111
 112 /* write_profiling_data - Write a raw block of profiling counters out to the
 113  * llvmprof.out file.  Note that we allow programs to be instrumented with
 114  * multiple different kinds of instrumentation.  For this reason, this function
 115  * may be called more than once.
 116  */
 117 void write_profiling_data(enum ProfilingType PT, unsigned *Start,
 118                           unsigned NumElements) {
 119   int PTy;
 120   int outFile = getOutFile();
 121
 122   /* Write out this record! */
 123   PTy = PT;
 124   if( write(outFile, &PTy, sizeof(int)) < 0 ||
 125       write(outFile, &NumElements, sizeof(unsigned)) < 0 ||
 126       write(outFile, Start, NumElements*sizeof(unsigned)) < 0 ) {
 127     fprintf(stderr,"error: unable to write to output file.");
 128     exit(0);
 129   }
 130 }