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
29static char *SavedArgs = 0;
30static unsigned SavedArgsLength = 0;
31
32static 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 */
37int 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  /* Defensively check for a zero length, even though this is unlikely
69   * to happen in practice.  This avoids calling malloc() below with a
70   * size of 0.
71   */
72  if (Length == 0) {
73    SavedArgs = 0;
74    SavedArgsLength = 0;
75    return argc;
76  }
77
78  SavedArgs = (char*)malloc(Length);
79  for (Length = 0, i = 0; i != (unsigned)argc; ++i) {
80    unsigned Len = strlen(argv[i]);
81    memcpy(SavedArgs+Length, argv[i], Len);
82    Length += Len;
83    SavedArgs[Length++] = ' ';
84  }
85
86  SavedArgsLength = Length;
87
88  return argc;
89}
90
91
92/*
93 * Retrieves the file descriptor for the profile file.
94 */
95int getOutFile() {
96  static int OutFile = -1;
97
98  /* If this is the first time this function is called, open the output file
99   * for appending, creating it if it does not already exist.
100   */
101  if (OutFile == -1) {
102    OutFile = open(OutputFilename, O_CREAT | O_WRONLY, 0666);
103    lseek(OutFile, 0, SEEK_END); /* O_APPEND prevents seeking */
104    if (OutFile == -1) {
105      fprintf(stderr, "LLVM profiling runtime: while opening '%s': ",
106              OutputFilename);
107      perror("");
108      return(OutFile);
109    }
110
111    /* Output the command line arguments to the file. */
112    {
113      int PTy = ArgumentInfo;
114      int Zeros = 0;
115      if (write(OutFile, &PTy, sizeof(int)) < 0 ||
116          write(OutFile, &SavedArgsLength, sizeof(unsigned)) < 0 ||
117          write(OutFile, SavedArgs, SavedArgsLength) < 0 ) {
118        fprintf(stderr,"error: unable to write to output file.");
119        exit(0);
120      }
121      /* Pad out to a multiple of four bytes */
122      if (SavedArgsLength & 3) {
123        if (write(OutFile, &Zeros, 4-(SavedArgsLength&3)) < 0) {
124          fprintf(stderr,"error: unable to write to output file.");
125          exit(0);
126        }
127      }
128    }
129  }
130  return(OutFile);
131}
132
133/* write_profiling_data - Write a raw block of profiling counters out to the
134 * llvmprof.out file.  Note that we allow programs to be instrumented with
135 * multiple different kinds of instrumentation.  For this reason, this function
136 * may be called more than once.
137 */
138void write_profiling_data(enum ProfilingType PT, unsigned *Start,
139                          unsigned NumElements) {
140  int PTy;
141  int outFile = getOutFile();
142
143  /* Write out this record! */
144  PTy = PT;
145  if( write(outFile, &PTy, sizeof(int)) < 0 ||
146      write(outFile, &NumElements, sizeof(unsigned)) < 0 ||
147      write(outFile, Start, NumElements*sizeof(unsigned)) < 0 ) {
148    fprintf(stderr,"error: unable to write to output file.");
149    exit(0);
150  }
151}
152