libiberty/dyn-string.c

   1 /* An abstract string datatype.
   2    Copyright (C) 1998-2020 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 In addition to the permissions in the GNU General Public License, the
  13 Free Software Foundation gives you unlimited permission to link the
  14 compiled version of this file into combinations with other programs,
  15 and to distribute those combinations without any restriction coming
  16 from the use of this file.  (The General Public License restrictions
  17 do apply in other respects; for example, they cover modification of
  18 the file, and distribution when not linked into a combined
  19 executable.)
  20
  21 GNU CC is distributed in the hope that it will be useful,
  22 but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 GNU General Public License for more details.
  25
  26 You should have received a copy of the GNU General Public License
  27 along with GNU CC; see the file COPYING.  If not, write to
  28 the Free Software Foundation, 51 Franklin Street - Fifth Floor,
  29 Boston, MA 02110-1301, USA.  */
  30
  31 #ifdef HAVE_CONFIG_H
  32 #include "config.h"
  33 #endif
  34
  35 #include <stdio.h>
  36
  37 #ifdef HAVE_STRING_H
  38 #include <string.h>
  39 #endif
  40
  41 #ifdef HAVE_STDLIB_H
  42 #include <stdlib.h>
  43 #endif
  44
  45 #include "libiberty.h"
  46 #include "dyn-string.h"
  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 (struct dyn_string *ds_struct_ptr, int space)
  60 {
  61   /* We need at least one byte in which to store the terminating NUL.  */
  62   if (space == 0)
  63     space = 1;
  64
  65 #ifdef RETURN_ON_ALLOCATION_FAILURE
  66   ds_struct_ptr->s = (char *) malloc (space);
  67   if (ds_struct_ptr->s == NULL)
  68     return 0;
  69 #else
  70   ds_struct_ptr->s = XNEWVEC (char, space);
  71 #endif
  72   ds_struct_ptr->allocated = space;
  73   ds_struct_ptr->length = 0;
  74   ds_struct_ptr->s[0] = '\0';
  75
  76   return 1;
  77 }
  78
  79 /* Create a new dynamic string capable of holding at least SPACE
  80    characters, including the terminating NUL.  If SPACE is 0, it will
  81    be silently increased to 1.  If RETURN_ON_ALLOCATION_FAILURE is
  82    defined and memory allocation fails, returns NULL.  Otherwise
  83    returns the newly allocated string.  */
  84
  85 dyn_string_t
  86 dyn_string_new (int space)
  87 {
  88   dyn_string_t result;
  89 #ifdef RETURN_ON_ALLOCATION_FAILURE
  90   result = (dyn_string_t) malloc (sizeof (struct dyn_string));
  91   if (result == NULL)
  92     return NULL;
  93   if (!dyn_string_init (result, space))
  94     {
  95       free (result);
  96       return NULL;
  97     }
  98 #else
  99   result = XNEW (struct dyn_string);
 100   dyn_string_init (result, space);
 101 #endif
 102   return result;
 103 }
 104
 105 /* Free the memory used by DS.  */
 106
 107 void
 108 dyn_string_delete (dyn_string_t ds)
 109 {
 110   free (ds->s);
 111   free (ds);
 112 }
 113
 114 /* Returns the contents of DS in a buffer allocated with malloc.  It
 115    is the caller's responsibility to deallocate the buffer using free.
 116    DS is then set to the empty string.  Deletes DS itself.  */
 117
 118 char*
 119 dyn_string_release (dyn_string_t ds)
 120 {
 121   /* Store the old buffer.  */
 122   char* result = ds->s;
 123   /* The buffer is no longer owned by DS.  */
 124   ds->s = NULL;
 125   /* Delete DS.  */
 126   free (ds);
 127   /* Return the old buffer.  */
 128   return result;
 129 }
 130
 131 /* Increase the capacity of DS so it can hold at least SPACE
 132    characters, plus the terminating NUL.  This function will not (at
 133    present) reduce the capacity of DS.  Returns DS on success.
 134
 135    If RETURN_ON_ALLOCATION_FAILURE is defined and a memory allocation
 136    operation fails, deletes DS and returns NULL.  */
 137
 138 dyn_string_t
 139 dyn_string_resize (dyn_string_t ds, int space)
 140 {
 141   int new_allocated = ds->allocated;
 142
 143   /* Increase SPACE to hold the NUL termination.  */
 144   ++space;
 145
 146   /* Increase allocation by factors of two.  */
 147   while (space > new_allocated)
 148     new_allocated *= 2;
 149
 150   if (new_allocated != ds->allocated)
 151     {
 152       ds->allocated = new_allocated;
 153       /* We actually need more space.  */
 154 #ifdef RETURN_ON_ALLOCATION_FAILURE
 155       ds->s = (char *) realloc (ds->s, ds->allocated);
 156       if (ds->s == NULL)
 157         {
 158           free (ds);
 159           return NULL;
 160         }
 161 #else
 162       ds->s = XRESIZEVEC (char, ds->s, ds->allocated);
 163 #endif
 164     }
 165
 166   return ds;
 167 }
 168
 169 /* Sets the contents of DS to the empty string.  */
 170
 171 void
 172 dyn_string_clear (dyn_string_t ds)
 173 {
 174   /* A dyn_string always has room for at least the NUL terminator.  */
 175   ds->s[0] = '\0';
 176   ds->length = 0;
 177 }
 178
 179 /* Makes the contents of DEST the same as the contents of SRC.  DEST
 180    and SRC must be distinct.  Returns 1 on success.  On failure, if
 181    RETURN_ON_ALLOCATION_FAILURE, deletes DEST and returns 0.  */
 182
 183 int
 184 dyn_string_copy (dyn_string_t dest, dyn_string_t src)
 185 {
 186   if (dest == src)
 187     abort ();
 188
 189   /* Make room in DEST.  */
 190   if (dyn_string_resize (dest, src->length) == NULL)
 191     return 0;
 192   /* Copy DEST into SRC.  */
 193   strcpy (dest->s, src->s);
 194   /* Update the size of DEST.  */
 195   dest->length = src->length;
 196   return 1;
 197 }
 198
 199 /* Copies SRC, a NUL-terminated string, into DEST.  Returns 1 on
 200    success.  On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST
 201    and returns 0.  */
 202
 203 int
 204 dyn_string_copy_cstr (dyn_string_t dest, const char *src)
 205 {
 206   int length = strlen (src);
 207   /* Make room in DEST.  */
 208   if (dyn_string_resize (dest, length) == NULL)
 209     return 0;
 210   /* Copy DEST into SRC.  */
 211   strcpy (dest->s, src);
 212   /* Update the size of DEST.  */
 213   dest->length = length;
 214   return 1;
 215 }
 216
 217 /* Inserts SRC at the beginning of DEST.  DEST is expanded as
 218    necessary.  SRC and DEST must be distinct.  Returns 1 on success.
 219    On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and
 220    returns 0.  */
 221
 222 int
 223 dyn_string_prepend (dyn_string_t dest, dyn_string_t src)
 224 {
 225   return dyn_string_insert (dest, 0, src);
 226 }
 227
 228 /* Inserts SRC, a NUL-terminated string, at the beginning of DEST.
 229    DEST is expanded as necessary.  Returns 1 on success.  On failure,
 230    if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and returns 0. */
 231
 232 int
 233 dyn_string_prepend_cstr (dyn_string_t dest, const char *src)
 234 {
 235   return dyn_string_insert_cstr (dest, 0, src);
 236 }
 237
 238 /* Inserts SRC into DEST starting at position POS.  DEST is expanded
 239    as necessary.  SRC and DEST must be distinct.  Returns 1 on
 240    success.  On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST
 241    and returns 0.  */
 242
 243 int
 244 dyn_string_insert (dyn_string_t dest, int pos, dyn_string_t src)
 245 {
 246   int i;
 247
 248   if (src == dest)
 249     abort ();
 250
 251   if (dyn_string_resize (dest, dest->length + src->length) == NULL)
 252     return 0;
 253   /* Make room for the insertion.  Be sure to copy the NUL.  */
 254   for (i = dest->length; i >= pos; --i)
 255     dest->s[i + src->length] = dest->s[i];
 256   /* Splice in the new stuff.  */
 257   strncpy (dest->s + pos, src->s, src->length);
 258   /* Compute the new length.  */
 259   dest->length += src->length;
 260   return 1;
 261 }
 262
 263 /* Inserts SRC, a NUL-terminated string, into DEST starting at
 264    position POS.  DEST is expanded as necessary.  Returns 1 on
 265    success.  On failure, RETURN_ON_ALLOCATION_FAILURE, deletes DEST
 266    and returns 0.  */
 267
 268 int
 269 dyn_string_insert_cstr (dyn_string_t dest, int pos, const char *src)
 270 {
 271   int i;
 272   int length = strlen (src);
 273
 274   if (dyn_string_resize (dest, dest->length + length) == NULL)
 275     return 0;
 276   /* Make room for the insertion.  Be sure to copy the NUL.  */
 277   for (i = dest->length; i >= pos; --i)
 278     dest->s[i + length] = dest->s[i];
 279   /* Splice in the new stuff.  */
 280   strncpy (dest->s + pos, src, length);
 281   /* Compute the new length.  */
 282   dest->length += length;
 283   return 1;
 284 }
 285
 286 /* Inserts character C into DEST starting at position POS.  DEST is
 287    expanded as necessary.  Returns 1 on success.  On failure,
 288    RETURN_ON_ALLOCATION_FAILURE, deletes DEST and returns 0.  */
 289
 290 int
 291 dyn_string_insert_char (dyn_string_t dest, int pos, int c)
 292 {
 293   int i;
 294
 295   if (dyn_string_resize (dest, dest->length + 1) == NULL)
 296     return 0;
 297   /* Make room for the insertion.  Be sure to copy the NUL.  */
 298   for (i = dest->length; i >= pos; --i)
 299     dest->s[i + 1] = dest->s[i];
 300   /* Add the new character.  */
 301   dest->s[pos] = c;
 302   /* Compute the new length.  */
 303   ++dest->length;
 304   return 1;
 305 }
 306
 307 /* Append S to DS, resizing DS if necessary.  Returns 1 on success.
 308    On failure, if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and
 309    returns 0.  */
 310
 311 int
 312 dyn_string_append (dyn_string_t dest, dyn_string_t s)
 313 {
 314   if (dyn_string_resize (dest, dest->length + s->length) == 0)
 315     return 0;
 316   strcpy (dest->s + dest->length, s->s);
 317   dest->length += s->length;
 318   return 1;
 319 }
 320
 321 /* Append the NUL-terminated string S to DS, resizing DS if necessary.
 322    Returns 1 on success.  On failure, if RETURN_ON_ALLOCATION_FAILURE,
 323    deletes DEST and returns 0.  */
 324
 325 int
 326 dyn_string_append_cstr (dyn_string_t dest, const char *s)
 327 {
 328   int len = strlen (s);
 329
 330   /* The new length is the old length plus the size of our string, plus
 331      one for the null at the end.  */
 332   if (dyn_string_resize (dest, dest->length + len) == NULL)
 333     return 0;
 334   strcpy (dest->s + dest->length, s);
 335   dest->length += len;
 336   return 1;
 337 }
 338
 339 /* Appends C to the end of DEST.  Returns 1 on success.  On failure,
 340    if RETURN_ON_ALLOCATION_FAILURE, deletes DEST and returns 0.  */
 341
 342 int
 343 dyn_string_append_char (dyn_string_t dest, int c)
 344 {
 345   /* Make room for the extra character.  */
 346   if (dyn_string_resize (dest, dest->length + 1) == NULL)
 347     return 0;
 348   /* Append the character; it will overwrite the old NUL.  */
 349   dest->s[dest->length] = c;
 350   /* Add a new NUL at the end.  */
 351   dest->s[dest->length + 1] = '\0';
 352   /* Update the length.  */
 353   ++(dest->length);
 354   return 1;
 355 }
 356
 357 /* Sets the contents of DEST to the substring of SRC starting at START
 358    and ending before END.  START must be less than or equal to END,
 359    and both must be between zero and the length of SRC, inclusive.
 360    Returns 1 on success.  On failure, if RETURN_ON_ALLOCATION_FAILURE,
 361    deletes DEST and returns 0.  */
 362
 363 int
 364 dyn_string_substring (dyn_string_t dest, dyn_string_t src,
 365                       int start, int end)
 366 {
 367   int i;
 368   int length = end - start;
 369
 370   if (start > end || start > src->length || end > src->length)
 371     abort ();
 372
 373   /* Make room for the substring.  */
 374   if (dyn_string_resize (dest, length) == NULL)
 375     return 0;
 376   /* Copy the characters in the substring,  */
 377   for (i = length; --i >= 0; )
 378     dest->s[i] = src->s[start + i];
 379   /* NUL-terimate the result.  */
 380   dest->s[length] = '\0';
 381   /* Record the length of the substring.  */
 382   dest->length = length;
 383
 384   return 1;
 385 }
 386
 387 /* Returns non-zero if DS1 and DS2 have the same contents.  */
 388
 389 int
 390 dyn_string_eq (dyn_string_t ds1, dyn_string_t ds2)
 391 {
 392   /* If DS1 and DS2 have different lengths, they must not be the same.  */
 393   if (ds1->length != ds2->length)
 394     return 0;
 395   else
 396     return !strcmp (ds1->s, ds2->s);
 397 }