gdb/gdbserver/remote-gutils.c

   1 /* General utility routines for the remote server for GDB.
   2    Copyright (C) 1986, 1989, 1993 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 2 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, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include <stdio.h>
  21 #include <sys/ioctl.h>
  22 #include "defs.h"
  23 #include <setjmp.h>
  24
  25 void error ();
  26 void fatal ();
  27
  28 /* Chain of cleanup actions established with make_cleanup,
  29    to be executed if an error happens.  */
  30
  31 static struct cleanup *cleanup_chain;
  32
  33 /* Nonzero means a quit has been requested.  */
  34
  35 int quit_flag;
  36
  37 /* Nonzero means quit immediately if Control-C is typed now,
  38    rather than waiting until QUIT is executed.  */
  39
  40 int immediate_quit;
  41 \f
  42 /* Add a new cleanup to the cleanup_chain,
  43    and return the previous chain pointer
  44    to be passed later to do_cleanups or discard_cleanups.
  45    Args are FUNCTION to clean up with, and ARG to pass to it.  */
  46
  47 struct cleanup *
  48 make_cleanup (function, arg)
  49      void (*function) ();
  50      PTR arg;
  51 {
  52   register struct cleanup *new
  53     = (struct cleanup *) xmalloc (sizeof (struct cleanup));
  54   register struct cleanup *old_chain = cleanup_chain;
  55
  56   new->next = cleanup_chain;
  57   new->function = function;
  58   new->arg = arg;
  59   cleanup_chain = new;
  60
  61   return old_chain;
  62 }
  63
  64 /* Discard cleanups and do the actions they describe
  65    until we get back to the point OLD_CHAIN in the cleanup_chain.  */
  66
  67 void
  68 do_cleanups (old_chain)
  69      register struct cleanup *old_chain;
  70 {
  71   register struct cleanup *ptr;
  72   while ((ptr = cleanup_chain) != old_chain)
  73     {
  74       (*ptr->function) (ptr->arg);
  75       cleanup_chain = ptr->next;
  76       free (ptr);
  77     }
  78 }
  79
  80 /* Discard cleanups, not doing the actions they describe,
  81    until we get back to the point OLD_CHAIN in the cleanup_chain.  */
  82
  83 void
  84 discard_cleanups (old_chain)
  85      register struct cleanup *old_chain;
  86 {
  87   register struct cleanup *ptr;
  88   while ((ptr = cleanup_chain) != old_chain)
  89     {
  90       cleanup_chain = ptr->next;
  91       free (ptr);
  92     }
  93 }
  94
  95 /* This function is useful for cleanups.
  96    Do
  97
  98      foo = xmalloc (...);
  99      old_chain = make_cleanup (free_current_contents, &foo);
 100
 101    to arrange to free the object thus allocated.  */
 102
 103 void
 104 free_current_contents (location)
 105      char **location;
 106 {
 107   free (*location);
 108 }
 109 \f
 110 /* Generally useful subroutines used throughout the program.  */
 111
 112 /* Like malloc but get error if no storage available.  */
 113
 114 PTR
 115 xmalloc (size)
 116      long size;
 117 {
 118   register char *val = (char *) malloc (size);
 119   if (!val)
 120     fatal ("virtual memory exhausted.", 0);
 121   return val;
 122 }
 123
 124 /* Like realloc but get error if no storage available.  */
 125
 126 PTR
 127 xrealloc (ptr, size)
 128      PTR ptr;
 129      long size;
 130 {
 131   register char *val = (char *) realloc (ptr, size);
 132   if (!val)
 133     fatal ("virtual memory exhausted.", 0);
 134   return val;
 135 }
 136
 137 /* Print the system error message for errno, and also mention STRING
 138    as the file name for which the error was encountered.
 139    Then return to command level.  */
 140
 141 void
 142 perror_with_name (string)
 143      char *string;
 144 {
 145   extern int sys_nerr;
 146   extern char *sys_errlist[];
 147   extern int errno;
 148   char *err;
 149   char *combined;
 150
 151   if (errno < sys_nerr)
 152     err = sys_errlist[errno];
 153   else
 154     err = "unknown error";
 155
 156   combined = (char *) alloca (strlen (err) + strlen (string) + 3);
 157   strcpy (combined, string);
 158   strcat (combined, ": ");
 159   strcat (combined, err);
 160
 161   error ("%s.", combined);
 162 }
 163
 164 /* Print the system error message for ERRCODE, and also mention STRING
 165    as the file name for which the error was encountered.  */
 166
 167 void
 168 print_sys_errmsg (string, errcode)
 169      char *string;
 170      int errcode;
 171 {
 172   extern int sys_nerr;
 173   extern char *sys_errlist[];
 174   char *err;
 175   char *combined;
 176
 177   if (errcode < sys_nerr)
 178     err = sys_errlist[errcode];
 179   else
 180     err = "unknown error";
 181
 182   combined = (char *) alloca (strlen (err) + strlen (string) + 3);
 183   strcpy (combined, string);
 184   strcat (combined, ": ");
 185   strcat (combined, err);
 186
 187   printf ("%s.\n", combined);
 188 }
 189
 190 void
 191 quit ()
 192 {
 193   fflush (stdout);
 194   ioctl (fileno (stdout), TIOCFLUSH, 0);
 195   error ("Quit");
 196 }
 197
 198 /* Control C comes here */
 199
 200 void
 201 request_quit (ignored)
 202      int ignored;
 203 {
 204   quit_flag = 1;
 205   if (immediate_quit)
 206     quit ();
 207 }
 208
 209 /* Print an error message and return to command level.
 210    STRING is the error message, used as a fprintf string,
 211    and ARG is passed as an argument to it.  */
 212
 213 NORETURN void
 214 error (string, arg1, arg2, arg3)
 215      char *string;
 216      int arg1, arg2, arg3;
 217 {
 218   extern jmp_buf toplevel;
 219
 220   fflush (stdout);
 221   fprintf (stderr, string, arg1, arg2, arg3);
 222   fprintf (stderr, "\n");
 223   longjmp(toplevel, 1);
 224 }
 225
 226 /* Print an error message and exit reporting failure.
 227    This is for a error that we cannot continue from.
 228    STRING and ARG are passed to fprintf.  */
 229
 230 void
 231 fatal (string, arg)
 232      char *string;
 233      int arg;
 234 {
 235   fprintf (stderr, "gdb: ");
 236   fprintf (stderr, string, arg);
 237   fprintf (stderr, "\n");
 238   exit (1);
 239 }
 240
 241 /* Make a copy of the string at PTR with SIZE characters
 242    (and add a null character at the end in the copy).
 243    Uses malloc to get the space.  Returns the address of the copy.  */
 244
 245 char *
 246 savestring (ptr, size)
 247      const char *ptr;
 248      int size;
 249 {
 250   register char *p = (char *) xmalloc (size + 1);
 251   bcopy (ptr, p, size);
 252   p[size] = 0;
 253   return p;
 254 }
 255
 256 void
 257 print_spaces (n, file)
 258      register int n;
 259      register FILE *file;
 260 {
 261   while (n-- > 0)
 262     fputc (' ', file);
 263 }
 264
 265 /* Ask user a y-or-n question and return 1 iff answer is yes.
 266    Takes three args which are given to printf to print the question.
 267    The first, a control string, should end in "? ".
 268    It should not say how to answer, because we do that.  */
 269
 270 int
 271 query (ctlstr, arg1, arg2)
 272      char *ctlstr;
 273 {
 274   register int answer;
 275
 276   /* Automatically answer "yes" if input is not from a terminal.  */
 277   /***********if (!input_from_terminal_p ())
 278     return 1; *************************/
 279
 280   while (1)
 281     {
 282       printf (ctlstr, arg1, arg2);
 283       printf ("(y or n) ");
 284       fflush (stdout);
 285       answer = fgetc (stdin);
 286       clearerr (stdin);         /* in case of C-d */
 287       if (answer != '\n')
 288         while (fgetc (stdin) != '\n')
 289           clearerr (stdin);
 290       if (answer >= 'a')
 291         answer -= 040;
 292       if (answer == 'Y')
 293         return 1;
 294       if (answer == 'N')
 295         return 0;
 296       printf ("Please answer y or n.\n");
 297     }
 298 }
 299 \f
 300 /* Parse a C escape sequence.  STRING_PTR points to a variable
 301    containing a pointer to the string to parse.  That pointer
 302    is updated past the characters we use.  The value of the
 303    escape sequence is returned.
 304
 305    A negative value means the sequence \ newline was seen,
 306    which is supposed to be equivalent to nothing at all.
 307
 308    If \ is followed by a null character, we return a negative
 309    value and leave the string pointer pointing at the null character.
 310
 311    If \ is followed by 000, we return 0 and leave the string pointer
 312    after the zeros.  A value of 0 does not mean end of string.  */
 313
 314 int
 315 parse_escape (string_ptr)
 316      char **string_ptr;
 317 {
 318   register int c = *(*string_ptr)++;
 319   switch (c)
 320     {
 321     case 'a':
 322       return '\a';
 323     case 'b':
 324       return '\b';
 325     case 'e':
 326       return 033;
 327     case 'f':
 328       return '\f';
 329     case 'n':
 330       return '\n';
 331     case 'r':
 332       return '\r';
 333     case 't':
 334       return '\t';
 335     case 'v':
 336       return '\v';
 337     case '\n':
 338       return -2;
 339     case 0:
 340       (*string_ptr)--;
 341       return 0;
 342     case '^':
 343       c = *(*string_ptr)++;
 344       if (c == '\\')
 345         c = parse_escape (string_ptr);
 346       if (c == '?')
 347         return 0177;
 348       return (c & 0200) | (c & 037);
 349
 350     case '0':
 351     case '1':
 352     case '2':
 353     case '3':
 354     case '4':
 355     case '5':
 356     case '6':
 357     case '7':
 358       {
 359         register int i = c - '0';
 360         register int count = 0;
 361         while (++count < 3)
 362           {
 363             if ((c = *(*string_ptr)++) >= '0' && c <= '7')
 364               {
 365                 i *= 8;
 366                 i += c - '0';
 367               }
 368             else
 369               {
 370                 (*string_ptr)--;
 371                 break;
 372               }
 373           }
 374         return i;
 375       }
 376     default:
 377       return c;
 378     }
 379 }
 380 \f
 381 void
 382 printchar (ch, stream)
 383      unsigned char ch;
 384      FILE *stream;
 385 {
 386   register int c = ch;
 387   if (c < 040 || c >= 0177)
 388     {
 389       if (c == '\n')
 390         fprintf (stream, "\\n");
 391       else if (c == '\b')
 392         fprintf (stream, "\\b");
 393       else if (c == '\t')
 394         fprintf (stream, "\\t");
 395       else if (c == '\f')
 396         fprintf (stream, "\\f");
 397       else if (c == '\r')
 398         fprintf (stream, "\\r");
 399       else if (c == 033)
 400         fprintf (stream, "\\e");
 401       else if (c == '\a')
 402         fprintf (stream, "\\a");
 403       else
 404         fprintf (stream, "\\%03o", c);
 405     }
 406   else
 407     {
 408       if (c == '\\' || c == '"' || c == '\'')
 409         fputc ('\\', stream);
 410       fputc (c, stream);
 411     }
 412 }