libiberty/dyn-string.c

   1 /* An abstract string datatype.
   2    Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
   3    Contributed by Mark Mitchell (mark@markmitchell.com).
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <stdio.h>
  27
  28 #ifdef HAVE_STRING_H
  29 #include <string.h>
  30 #endif
  31
  32 #ifdef HAVE_STDLIB_H
  33 #include <stdlib.h>
  34 #endif
  35
  36 #include "libiberty.h"
  37 #include "dyn-string.h"
  38
  39 /* If this file is being compiled for inclusion in the C++ runtime
  40    library, as part of the demangler implementation, we don't want to
  41    abort if an allocation fails.  Instead, percolate an error code up
  42    through the call chain.  */
  43
  44 #ifdef IN_LIBGCC2
  45 #define RETURN_ON_ALLOCATION_FAILURE
  46 #endif
  47
  48 /* Performs in-place initialization of a dyn_string struct.  This
  49    function can be used with a dyn_string struct on the stack or
  50    embedded in another object.  The contents of of the string itself
  51    are still dynamically allocated.  The string initially is capable
  52    of holding at least SPACE characeters, including the terminating
  53    NUL.  If SPACE is 0, it will silently be increated to 1.
  54
  55    If RETURN_ON_ALLOCATION_FAILURE is defined and memory allocation
  56    fails, returns 0.  Otherwise returns 1.  */
  57
  58 int
  59 dyn_string_init (ds_struct_ptr, space)
  60      struct dyn_string *ds_struct_ptr;
  61      int space;
  62 {
  63   /* We need at least one byte in which to store the terminating NUL.  */
  64   if (space == 0)
  65     space = 1;
  66
  67 #ifdef RETURN_ON_ALLOCATION_FAILURE
  68   ds_struct_ptr->s = (char *) malloc (space);
  69   if (ds_struct_ptr->s == NULL)
  70     return 0;
  71 #else
  72   ds_struct_ptr->s = (char *) xmalloc (space);
  73 #endif
  74   ds_struct_ptr->allocated = space;
  75   ds_struct_ptr->length = 0;
  76   ds_struct_ptr->s[0] = '\0';
  77
  78   return 1;
  79 }
  80
  81 /* Create a new dynamic string capable of holding at least SPACE
  82    characters, including the terminating NUL.  If SPACE is 0, it will
  83    be silently increased to 1.  If RETURN_ON_ALLOCATION_FAILURE is
  84    defined and memory allocation fails, returns NULL.  Otherwise
  85    returns the newly allocated string.  */
  86
  87 dyn_string_t
  88 dyn_string_new (space)
  89      int space;
  90 {
  91   dyn_string_t result;
  92 #ifdef RETURN_ON_ALLOCATION_FAILURE
  93   result = (dyn_string_t) malloc (sizeof (struct dyn_string));
  94   if (result == NULL)
  95     return NULL;
  96   if (!dyn_string_init (result, space))
  97     {
  98       free (result);
  99       return NULL;
 100     }
 101 #else
 102   result = (dyn_string_t) xmalloc (sizeof (struct dyn_string));
 103   dyn_string_init (result, space);
 104 #endif
 105   return result;
 106 }
 107
 108 /* Free the memory used by DS.  */
 109
 110 void
 111 dyn_string_delete (ds)
 112      dyn_string_t ds;
 113 {
 114   free (ds->s);
 115   free (ds);
 116 }
 117
 118 /* Returns the contents of DS in a buffer allocated with malloc.  It
 119    is the caller's responsibility to deallocate the buffer using free.
 120    DS is then set to the empty string.  Deletes DS itself.  */
 121
 122 char*
 123 dyn_string_release (ds)
 124      dyn_string_t ds;
 125 {
 126   /* Store the old buffer.  */
 127   char* result = ds->s;
 128   /* The buffer is no longer owned by DS.  */
 129   ds->s = NULL;
 130   /* Delete DS.  */
 131   free (ds);
 132   /* Return the old buffer.  */
 133   return result;
 134 }
 135
 136 /* Increase the capacity of DS so it can hold at least SPACE
 137    characters, plus the terminating NUL.  This function will not (at
 138    present) reduce the capacity of DS.  Returns DS on success.
 139
 140    If RETURN_ON_ALLOCATION_FAILURE is defined and a memory allocation
 141    operation fails, deletes DS and returns NULL.  */
 142
 143 dyn_string_t
 144 dyn_string_resize (ds, space)
 145      dyn_string_t ds;
 146      int space;
 147 {
 148   int new_allocated = ds->allocated;
 149
 150   /* Increase SPACE to hold the NUL termination.  */
 151   ++space;
 152
 153   /* Increase allocation by factors of two.  */
 154   while (space > new_allocated)
 155     new_allocated *= 2;
 156
 157   if (new_allocated != ds->allocated)
 158     {
 159       ds->allocated = new_allocated;
 160       /* We actually need more space.  */
 161 #ifdef RETURN_ON_ALLOCATION_FAILURE
 162       ds->s = (char *) realloc (ds->s, ds->allocated);
 163       if (ds->s == NULL)
 164         {
 165           free (ds);
 166           return NULL;
 167         }
 168 #else
 169       ds->s = (char *) xrealloc (ds->s, ds->allocated);
 170 #endif
 171     }
 172
 173   return ds;
 174 }
 175
 176 /* Sets the contents of DS to the empty string.  */
 177
 178 void
 179 dyn_string_clear (ds)
 180      dyn_string_t ds;
 181 {
 182   /* A dyn_string always has room for at least the NUL terminator.  */
 183   ds->s[0] = '\0';
 184   ds->length = 0;
 185 }
 186
 187 /* Makes the contents of DEST the same as the contents of SRC.  DEST
 188    and SRC must be distinct.  Returns 1 on success.  On failure, if
 189    RETURN_ON_ALLOCATION_FAILURE, deletes DEST and returns 0.  */
 190
 191 int
 192 dyn_string_copy (dest, src)
 193      dyn_string_t dest;
 194      dyn_string_t src;
 195 {
 196   if (dest == src)
 197     abort ();
 198
 199   /* Make room in DEST.  */
 200   if (dyn_string_resize (dest, src->length) == NULL)
 201     return 0;
 202   /* Copy DEST into SRC.  */
 203   strcpy (dest->s, src->s);
 204   /* Update the size of DEST.  */
 205   dest->length = src->length;
 206   return 1;
 207 }
 208
 209 /* Copies SRC, a NUL-terminated string, into DEST.  Returns 1 on
 210    success.  On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST
 211    and returns 0.  */
 212
 213 int
 214 dyn_string_copy_cstr (dest, src)
 215      dyn_string_t dest;
 216      const char *src;
 217 {
 218   int length = strlen (src);
 219   /* Make room in DEST.  */
 220   if (dyn_string_resize (dest, length) == NULL)
 221     return 0;
 222   /* Copy DEST into SRC.  */
 223   strcpy (dest->s, src);
 224   /* Update the size of DEST.  */
 225   dest->length = length;
 226   return 1;
 227 }
 228
 229 /* Inserts SRC at the beginning of DEST.  DEST is expanded as
 230    necessary.  SRC and DEST must be distinct.  Returns 1 on success.
 231    On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and
 232    returns 0.  */
 233
 234 int
 235 dyn_string_prepend (dest, src)
 236      dyn_string_t dest;
 237      dyn_string_t src;
 238 {
 239   return dyn_string_insert (dest, 0, src);
 240 }
 241
 242 /* Inserts SRC, a NUL-terminated string, at the beginning of DEST.
 243    DEST is expanded as necessary.  Returns 1 on success.  On failure,
 244    if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and returns 0. */
 245
 246 int
 247 dyn_string_prepend_cstr (dest, src)
 248      dyn_string_t dest;
 249      const char *src;
 250 {
 251   return dyn_string_insert_cstr (dest, 0, src);
 252 }
 253
 254 /* Inserts SRC into DEST starting at position POS.  DEST is expanded
 255    as necessary.  SRC and DEST must be distinct.  Returns 1 on
 256    success.  On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST
 257    and returns 0.  */
 258
 259 int
 260 dyn_string_insert (dest, pos, src)
 261      dyn_string_t dest;
 262      int pos;
 263      dyn_string_t src;
 264 {
 265   int i;
 266
 267   if (src == dest)
 268     abort ();
 269
 270   if (dyn_string_resize (dest, dest->length + src->length) == NULL)
 271     return 0;
 272   /* Make room for the insertion.  Be sure to copy the NUL.  */
 273   for (i = dest->length; i >= pos; --i)
 274     dest->s[i + src->length] = dest->s[i];
 275   /* Splice in the new stuff.  */
 276   strncpy (dest->s + pos, src->s, src->length);
 277   /* Compute the new length.  */
 278   dest->length += src->length;
 279   return 1;
 280 }
 281
 282 /* Inserts SRC, a NUL-terminated string, into DEST starting at
 283    position POS.  DEST is expanded as necessary.  Returns 1 on
 284    success.  On failure, RETURN_ON_ALLOCATION_FAILURE, deletes DEST
 285    and returns 0.  */
 286
 287 int
 288 dyn_string_insert_cstr (dest, pos, src)
 289      dyn_string_t dest;
 290      int pos;
 291      const char *src;
 292 {
 293   int i;
 294   int length = strlen (src);
 295
 296   if (dyn_string_resize (dest, dest->length + length) == NULL)
 297     return 0;
 298   /* Make room for the insertion.  Be sure to copy the NUL.  */
 299   for (i = dest->length; i >= pos; --i)
 300     dest->s[i + length] = dest->s[i];
 301   /* Splice in the new stuff.  */
 302   strncpy (dest->s + pos, src, length);
 303   /* Compute the new length.  */
 304   dest->length += length;
 305   return 1;
 306 }
 307
 308 /* Append S to DS, resizing DS if necessary.  Returns 1 on success.
 309    On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and
 310    returns 0.  */
 311
 312 int
 313 dyn_string_append (dest, s)
 314      dyn_string_t dest;
 315      dyn_string_t s;
 316 {
 317   if (dyn_string_resize (dest, dest->length + s->length) == 0)
 318     return 0;
 319   strcpy (dest->s + dest->length, s->s);
 320   dest->length += s->length;
 321   return 1;
 322 }
 323
 324 /* Append the NUL-terminated string S to DS, resizing DS if necessary.
 325    Returns 1 on success.  On failure, if RETURN_ON_ALLOCATION_FAILURE,
 326    deletes DEST and returns 0.  */
 327
 328 int
 329 dyn_string_append_cstr (dest, s)
 330      dyn_string_t dest;
 331      const char *s;
 332 {
 333   int len = strlen (s);
 334
 335   /* The new length is the old length plus the size of our string, plus
 336      one for the null at the end.  */
 337   if (dyn_string_resize (dest, dest->length + len) == NULL)
 338     return 0;
 339   strcpy (dest->s + dest->length, s);
 340   dest->length += len;
 341   return 1;
 342 }
 343
 344 /* Appends C to the end of DEST.  Returns 1 on success.  On failiure,
 345    if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and returns 0.  */
 346
 347 int
 348 dyn_string_append_char (dest, c)
 349      dyn_string_t dest;
 350      int c;
 351 {
 352   /* Make room for the extra character.  */
 353   if (dyn_string_resize (dest, dest->length + 1) == NULL)
 354     return 0;
 355   /* Append the character; it will overwrite the old NUL.  */
 356   dest->s[dest->length] = c;
 357   /* Add a new NUL at the end.  */
 358   dest->s[dest->length + 1] = '\0';
 359   /* Update the length.  */
 360   ++(dest->length);
 361   return 1;
 362 }
 363
 364 /* Sets the contents of DEST to the substring of SRC starting at START
 365    and ending before END.  START must be less than or equal to END,
 366    and both must be between zero and the length of SRC, inclusive.
 367    Returns 1 on success.  On failure, if RETURN_ON_ALLOCATION_FAILURE,
 368    deletes DEST and returns 0.  */
 369
 370 int
 371 dyn_string_substring (dest, src, start, end)
 372      dyn_string_t dest;
 373      dyn_string_t src;
 374      int start;
 375      int end;
 376 {
 377   int i;
 378   int length = end - start;
 379
 380   if (start > end || start > src->length || end > src->length)
 381     abort ();
 382
 383   /* Make room for the substring.  */
 384   if (dyn_string_resize (dest, length) == NULL)
 385     return 0;
 386   /* Copy the characters in the substring,  */
 387   for (i = length; --i >= 0; )
 388     dest->s[i] = src->s[start + i];
 389   /* NUL-terimate the result.  */
 390   dest->s[length] = '\0';
 391   /* Record the length of the substring.  */
 392   dest->length = length;
 393
 394   return 1;
 395 }
 396
 397 /* Returns non-zero if DS1 and DS2 have the same contents.  */
 398
 399 int
 400 dyn_string_eq (ds1, ds2)
 401      dyn_string_t ds1;
 402      dyn_string_t ds2;
 403 {
 404   /* If DS1 and DS2 have different lengths, they must not be the same.  */
 405   if (ds1->length != ds2->length)
 406     return 0;
 407   else
 408     return !strcmp (ds1->s, ds2->s);
 409 }