gdb/gdbserver/debug.c

   1 /* Debugging routines for the remote server for GDB.
   2    Copyright (C) 2014-2019 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 /* Enable miscellaneous debugging output.  The name is historical - it
  30    was originally used to debug LinuxThreads support.  */
  31 int debug_threads;
  32
  33 /* Include timestamps in debugging output.  */
  34 int debug_timestamp;
  35
  36 #if !defined (IN_PROCESS_AGENT)
  37
  38 /* See debug.h.  */
  39
  40 void
  41 debug_set_output (const char *new_debug_file)
  42 {
  43   /* Close any existing file and reset to standard error.  */
  44   if (debug_file != stderr)
  45     {
  46       fclose (debug_file);
  47     }
  48   debug_file = stderr;
  49
  50   /* Catch empty filenames.  */
  51   if (new_debug_file == nullptr || strlen (new_debug_file) == 0)
  52     return;
  53
  54   FILE *fptr = fopen (new_debug_file, "w");
  55
  56   if (fptr == nullptr)
  57     {
  58       debug_printf ("Cannot open %s for writing. %s. Switching to stderr.\n",
  59                     new_debug_file, strerror (errno));
  60       return;
  61     }
  62
  63   debug_file = fptr;
  64 }
  65
  66 #endif
  67
  68 /* Print a debugging message.
  69    If the text begins a new line it is preceded by a timestamp.
  70    We don't get fancy with newline checking, we just check whether the
  71    previous call ended with "\n".  */
  72
  73 void
  74 debug_vprintf (const char *format, va_list ap)
  75 {
  76 #if !defined (IN_PROCESS_AGENT)
  77   /* N.B. Not thread safe, and can't be used, as is, with IPA.  */
  78   static int new_line = 1;
  79
  80   if (debug_timestamp && new_line)
  81     {
  82       using namespace std::chrono;
  83
  84       steady_clock::time_point now = steady_clock::now ();
  85       seconds s = duration_cast<seconds> (now.time_since_epoch ());
  86       microseconds us = duration_cast<microseconds> (now.time_since_epoch ()) - s;
  87
  88       fprintf (debug_file, "%ld.%06ld ", (long) s.count (), (long) us.count ());
  89     }
  90 #endif
  91
  92   vfprintf (debug_file, format, ap);
  93
  94 #if !defined (IN_PROCESS_AGENT)
  95   if (*format)
  96     new_line = format[strlen (format) - 1] == '\n';
  97 #endif
  98 }
  99
 100 /* Flush debugging output.
 101    This is called, for example, when starting an inferior to ensure all debug
 102    output thus far appears before any inferior output.  */
 103
 104 void
 105 debug_flush (void)
 106 {
 107   fflush (debug_file);
 108 }
 109
 110 /* Notify the user that the code is entering FUNCTION_NAME.
 111    FUNCTION_NAME is the name of the calling function, or NULL if unknown.
 112
 113    This is intended to be called via the debug_enter macro.  */
 114
 115 void
 116 do_debug_enter (const char *function_name)
 117 {
 118   if (function_name != NULL)
 119     debug_printf (">>>> entering %s\n", function_name);
 120 }
 121
 122 /* Notify the user that the code is exiting FUNCTION_NAME.
 123    FUNCTION_NAME is the name of the calling function, or NULL if unknown.
 124
 125    This is intended to be called via the debug_exit macro.  */
 126
 127 void
 128 do_debug_exit (const char *function_name)
 129 {
 130   if (function_name != NULL)
 131     debug_printf ("<<<< exiting %s\n", function_name);
 132 }
 133
 134 /* See debug.h.  */
 135
 136 ssize_t
 137 debug_write (const void *buf, size_t nbyte)
 138 {
 139   int fd = fileno (debug_file);
 140   return write (fd, buf, nbyte);
 141 }