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      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((char**)&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((char**)&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       if (write(OutFile, &PTy, sizeof(int)) < 0 ||
    106           write(OutFile, &SavedArgsLength, sizeof(unsigned)) < 0 ||
    107           write(OutFile, SavedArgs, SavedArgsLength) < 0 ) {
    108         fprintf(stderr,"error: unable to write to output file.");
    109         exit(0);
    110       }
    111       /* Pad out to a multiple of four bytes */
    112       if (SavedArgsLength & 3) {
    113         if (write(OutFile, &Zeros, 4-(SavedArgsLength&3)) < 0) {
    114           fprintf(stderr,"error: unable to write to output file.");
    115           exit(0);
    116         }
    117       }
    118     }
    119   }
    120   return(OutFile);
    121 }
    122 
    123 /* write_profiling_data - Write a raw block of profiling counters out to the
    124  * llvmprof.out file.  Note that we allow programs to be instrumented with
    125  * multiple different kinds of instrumentation.  For this reason, this function
    126  * may be called more than once.
    127  */
    128 void write_profiling_data(enum ProfilingType PT, unsigned *Start,
    129                           unsigned NumElements) {
    130   int PTy;
    131   int outFile = getOutFile();
    132 
    133   /* Write out this record! */
    134   PTy = PT;
    135   if( write(outFile, &PTy, sizeof(int)) < 0 ||
    136       write(outFile, &NumElements, sizeof(unsigned)) < 0 ||
    137       write(outFile, Start, NumElements*sizeof(unsigned)) < 0 ) {
    138     fprintf(stderr,"error: unable to write to output file.");
    139     exit(0);
    140   }
    141 }
    142