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 #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
  32 static const char *OutputFilename = "llvmprof.out";
  33
  34 /* save_arguments - Save argc and argv as passed into the program for the file
  35  * we output.
  36  */
  37 int save_arguments(int argc, const char **argv) {
  38   unsigned Length, i;
  39   if (SavedArgs || !argv) return argc;  /* This can be called multiple times */
  40
  41   /* Check to see if there are any arguments passed into the program for the
  42    * profiler.  If there are, strip them off and remember their settings.
  43    */
  44   while (argc > 1 && !strncmp(argv[1], "-llvmprof-", 10)) {
  45     /* Ok, we have an llvmprof argument.  Remove it from the arg list and decide
  46      * what to do with it.
  47      */
  48     const char *Arg = argv[1];
  49     memmove(&argv[1], &argv[2], (argc-1)*sizeof(char*));
  50     --argc;
  51
  52     if (!strcmp(Arg, "-llvmprof-output")) {
  53       if (argc == 1)
  54         puts("-llvmprof-output requires a filename argument!");
  55       else {
  56         OutputFilename = strdup(argv[1]);
  57         memmove(&argv[1], &argv[2], (argc-1)*sizeof(char*));
  58         --argc;
  59       }
  60     } else {
  61       printf("Unknown option to the profiler runtime: '%s' - ignored.\n", Arg);
  62     }
  63   }
  64
  65   for (Length = 0, i = 0; i != (unsigned)argc; ++i)
  66     Length += strlen(argv[i])+1;
  67
  68   SavedArgs = (char*)malloc(Length);
  69   for (Length = 0, i = 0; i != (unsigned)argc; ++i) {
  70     unsigned Len = strlen(argv[i]);
  71     memcpy(SavedArgs+Length, argv[i], Len);
  72     Length += Len;
  73     SavedArgs[Length++] = ' ';
  74   }
  75
  76   SavedArgsLength = Length;
  77
  78   return argc;
  79 }
  80
  81
  82 /*
  83  * Retrieves the file descriptor for the profile file.
  84  */
  85 int getOutFile() {
  86   static int OutFile = -1;
  87
  88   /* If this is the first time this function is called, open the output file
  89    * for appending, creating it if it does not already exist.
  90    */
  91   if (OutFile == -1) {
  92     OutFile = open(OutputFilename, O_CREAT | O_WRONLY, 0666);
  93     lseek(OutFile, 0, SEEK_END); /* O_APPEND prevents seeking */
  94     if (OutFile == -1) {
  95       fprintf(stderr, "LLVM profiling runtime: while opening '%s': ",
  96               OutputFilename);
  97       perror("");
  98       return(OutFile);
  99     }
 100
 101     /* Output the command line arguments to the file. */
 102     {
 103       int PTy = ArgumentInfo;
 104       int Zeros = 0;
 105       write(OutFile, &PTy, sizeof(int));
 106       write(OutFile, &SavedArgsLength, sizeof(unsigned));
 107       write(OutFile, SavedArgs, SavedArgsLength);
 108       /* Pad out to a multiple of four bytes */
 109       if (SavedArgsLength & 3)
 110         write(OutFile, &Zeros, 4-(SavedArgsLength&3));
 111     }
 112   }
 113   return(OutFile);
 114 }
 115
 116 /* write_profiling_data - Write a raw block of profiling counters out to the
 117  * llvmprof.out file.  Note that we allow programs to be instrumented with
 118  * multiple different kinds of instrumentation.  For this reason, this function
 119  * may be called more than once.
 120  */
 121 void write_profiling_data(enum ProfilingType PT, unsigned *Start,
 122                           unsigned NumElements) {
 123   int PTy;
 124   int outFile = getOutFile();
 125
 126   /* Write out this record! */
 127   PTy = PT;
 128   if( write(outFile, &PTy, sizeof(int)) < 0 ||
 129       write(outFile, &NumElements, sizeof(unsigned)) < 0 ||
 130       write(outFile, Start, NumElements*sizeof(unsigned)) < 0 ) {
 131     fprintf(stderr,"error: unable to write to output file.");
 132     exit(0);
 133   }
 134 }