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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  */
save_arguments(int argc,const char ** argv)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  */
getOutFile()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  */
write_profiling_data(enum ProfilingType PT,unsigned * Start,unsigned NumElements)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