gdbserver/debug.cc

   1 /* Debugging routines for the remote server for GDB.
   2    Copyright (C) 2014-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "server.h"
  20 #include <chrono>
  21
  22 #if !defined (IN_PROCESS_AGENT)
  23 int remote_debug = 0;
  24 #endif
  25
  26 /* Output file for debugging.  Default to standard error.  */
  27 FILE *debug_file = stderr;
  28
  29 /* See debug.h.  */
  30 int debug_threads;
  31
  32 /* Include timestamps in debugging output.  */
  33 int debug_timestamp;
  34
  35 #if !defined (IN_PROCESS_AGENT)
  36
  37 /* See debug.h.  */
  38
  39 void
  40 debug_set_output (const char *new_debug_file)
  41 {
  42   /* Close any existing file and reset to standard error.  */
  43   if (debug_file != stderr)
  44     {
  45       fclose (debug_file);
  46     }
  47   debug_file = stderr;
  48
  49   /* Catch empty filenames.  */
  50   if (new_debug_file == nullptr || strlen (new_debug_file) == 0)
  51     return;
  52
  53   FILE *fptr = fopen (new_debug_file, "w");
  54
  55   if (fptr == nullptr)
  56     {
  57       debug_printf ("Cannot open %s for writing. %s. Switching to stderr.\n",
  58                     new_debug_file, safe_strerror (errno));
  59       return;
  60     }
  61
  62   debug_file = fptr;
  63 }
  64
  65 #endif
  66
  67 /* Print a debugging message.
  68    If the text begins a new line it is preceded by a timestamp.
  69    We don't get fancy with newline checking, we just check whether the
  70    previous call ended with "\n".  */
  71
  72 void
  73 debug_vprintf (const char *format, va_list ap)
  74 {
  75 #if !defined (IN_PROCESS_AGENT)
  76   /* N.B. Not thread safe, and can't be used, as is, with IPA.  */
  77   static int new_line = 1;
  78
  79   if (debug_timestamp && new_line)
  80     {
  81       using namespace std::chrono;
  82
  83       steady_clock::time_point now = steady_clock::now ();
  84       seconds s = duration_cast<seconds> (now.time_since_epoch ());
  85       microseconds us = duration_cast<microseconds> (now.time_since_epoch ()) - s;
  86
  87       fprintf (debug_file, "%ld.%06ld ", (long) s.count (), (long) us.count ());
  88     }
  89 #endif
  90
  91   vfprintf (debug_file, format, ap);
  92
  93 #if !defined (IN_PROCESS_AGENT)
  94   if (*format)
  95     new_line = format[strlen (format) - 1] == '\n';
  96 #endif
  97 }
  98
  99 /* Flush debugging output.
 100    This is called, for example, when starting an inferior to ensure all debug
 101    output thus far appears before any inferior output.  */
 102
 103 void
 104 debug_flush (void)
 105 {
 106   fflush (debug_file);
 107 }
 108
 109 /* Notify the user that the code is entering FUNCTION_NAME.
 110    FUNCTION_NAME is the name of the calling function, or NULL if unknown.
 111
 112    This is intended to be called via the debug_enter macro.  */
 113
 114 void
 115 do_debug_enter (const char *function_name)
 116 {
 117   if (function_name != NULL)
 118     debug_printf (">>>> entering %s\n", function_name);
 119 }
 120
 121 /* Notify the user that the code is exiting FUNCTION_NAME.
 122    FUNCTION_NAME is the name of the calling function, or NULL if unknown.
 123
 124    This is intended to be called via the debug_exit macro.  */
 125
 126 void
 127 do_debug_exit (const char *function_name)
 128 {
 129   if (function_name != NULL)
 130     debug_printf ("<<<< exiting %s\n", function_name);
 131 }
 132
 133 /* See debug.h.  */
 134
 135 ssize_t
 136 debug_write (const void *buf, size_t nbyte)
 137 {
 138   int fd = fileno (debug_file);
 139   return write (fd, buf, nbyte);
 140 }