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