gdbserver/debug.cc

   1 /* Debugging routines for the remote server for GDB.
   2    Copyright (C) 2014-2022 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 static 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 /* See gdbsupport/common-debug.h.  */
  68
  69 int debug_print_depth = 0;
  70
  71 /* Print a debugging message.
  72    If the text begins a new line it is preceded by a timestamp.
  73    We don't get fancy with newline checking, we just check whether the
  74    previous call ended with "\n".  */
  75
  76 void
  77 debug_vprintf (const char *format, va_list ap)
  78 {
  79 #if !defined (IN_PROCESS_AGENT)
  80   /* N.B. Not thread safe, and can't be used, as is, with IPA.  */
  81   static int new_line = 1;
  82
  83   if (debug_timestamp && new_line)
  84     {
  85       using namespace std::chrono;
  86
  87       steady_clock::time_point now = steady_clock::now ();
  88       seconds s = duration_cast<seconds> (now.time_since_epoch ());
  89       microseconds us = duration_cast<microseconds> (now.time_since_epoch ()) - s;
  90
  91       fprintf (debug_file, "%ld.%06ld ", (long) s.count (), (long) us.count ());
  92     }
  93 #endif
  94
  95   vfprintf (debug_file, format, ap);
  96
  97 #if !defined (IN_PROCESS_AGENT)
  98   if (*format)
  99     new_line = format[strlen (format) - 1] == '\n';
 100 #endif
 101 }
 102
 103 /* Flush debugging output.
 104    This is called, for example, when starting an inferior to ensure all debug
 105    output thus far appears before any inferior output.  */
 106
 107 void
 108 debug_flush (void)
 109 {
 110   fflush (debug_file);
 111 }
 112
 113 /* Notify the user that the code is entering FUNCTION_NAME.
 114    FUNCTION_NAME is the name of the calling function, or NULL if unknown.
 115
 116    This is intended to be called via the debug_enter macro.  */
 117
 118 void
 119 do_debug_enter (const char *function_name)
 120 {
 121   if (function_name != NULL)
 122     debug_printf (">>>> entering %s\n", function_name);
 123 }
 124
 125 /* Notify the user that the code is exiting FUNCTION_NAME.
 126    FUNCTION_NAME is the name of the calling function, or NULL if unknown.
 127
 128    This is intended to be called via the debug_exit macro.  */
 129
 130 void
 131 do_debug_exit (const char *function_name)
 132 {
 133   if (function_name != NULL)
 134     debug_printf ("<<<< exiting %s\n", function_name);
 135 }
 136
 137 /* See debug.h.  */
 138
 139 ssize_t
 140 debug_write (const void *buf, size_t nbyte)
 141 {
 142   int fd = fileno (debug_file);
 143   return write (fd, buf, nbyte);
 144 }