| 1 | /* sb.c - string buffer manipulation routines |
| 2 | Copyright (C) 1994-2018 Free Software Foundation, Inc. |
| 3 | |
| 4 | Written by Steve and Judy Chamberlain of Cygnus Support, |
| 5 | sac@cygnus.com |
| 6 | |
| 7 | This file is part of GAS, the GNU Assembler. |
| 8 | |
| 9 | GAS is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3, or (at your option) |
| 12 | any later version. |
| 13 | |
| 14 | GAS is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with GAS; see the file COPYING. If not, write to the Free |
| 21 | Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA |
| 22 | 02110-1301, USA. */ |
| 23 | |
| 24 | #include "as.h" |
| 25 | #include "sb.h" |
| 26 | |
| 27 | #ifdef HAVE_LIMITS_H |
| 28 | #include <limits.h> |
| 29 | #endif |
| 30 | #ifndef CHAR_BIT |
| 31 | #define CHAR_BIT 8 |
| 32 | #endif |
| 33 | |
| 34 | /* These routines are about manipulating strings. |
| 35 | |
| 36 | They are managed in things called `sb's which is an abbreviation |
| 37 | for string buffers. An sb has to be created, things can be glued |
| 38 | on to it, and at the end of it's life it should be freed. The |
| 39 | contents should never be pointed at whilst it is still growing, |
| 40 | since it could be moved at any time |
| 41 | |
| 42 | eg: |
| 43 | sb_new (&foo); |
| 44 | sb_grow... (&foo,...); |
| 45 | use foo->ptr[*]; |
| 46 | sb_kill (&foo); */ |
| 47 | |
| 48 | /* Buffers start at INIT_ALLOC size, and roughly double each time we |
| 49 | go over the current allocation. MALLOC_OVERHEAD is a guess at the |
| 50 | system malloc overhead. We aim to not waste any memory in the |
| 51 | underlying page/chunk allocated by the system malloc. */ |
| 52 | #define MALLOC_OVERHEAD (2 * sizeof (size_t)) |
| 53 | #define INIT_ALLOC (64 - MALLOC_OVERHEAD - 1) |
| 54 | |
| 55 | static void sb_check (sb *, size_t); |
| 56 | |
| 57 | /* Initializes an sb. */ |
| 58 | |
| 59 | void |
| 60 | sb_build (sb *ptr, size_t size) |
| 61 | { |
| 62 | ptr->ptr = XNEWVEC (char, size + 1); |
| 63 | ptr->max = size; |
| 64 | ptr->len = 0; |
| 65 | } |
| 66 | |
| 67 | void |
| 68 | sb_new (sb *ptr) |
| 69 | { |
| 70 | sb_build (ptr, INIT_ALLOC); |
| 71 | } |
| 72 | |
| 73 | /* Deallocate the sb at ptr. */ |
| 74 | |
| 75 | void |
| 76 | sb_kill (sb *ptr) |
| 77 | { |
| 78 | free (ptr->ptr); |
| 79 | } |
| 80 | |
| 81 | /* Add the sb at s to the end of the sb at ptr. */ |
| 82 | |
| 83 | void |
| 84 | sb_add_sb (sb *ptr, sb *s) |
| 85 | { |
| 86 | sb_check (ptr, s->len); |
| 87 | memcpy (ptr->ptr + ptr->len, s->ptr, s->len); |
| 88 | ptr->len += s->len; |
| 89 | } |
| 90 | |
| 91 | /* Helper for sb_scrub_and_add_sb. */ |
| 92 | |
| 93 | static sb *sb_to_scrub; |
| 94 | static char *scrub_position; |
| 95 | static size_t |
| 96 | scrub_from_sb (char *buf, size_t buflen) |
| 97 | { |
| 98 | size_t copy; |
| 99 | copy = sb_to_scrub->len - (scrub_position - sb_to_scrub->ptr); |
| 100 | if (copy > buflen) |
| 101 | copy = buflen; |
| 102 | memcpy (buf, scrub_position, copy); |
| 103 | scrub_position += copy; |
| 104 | return copy; |
| 105 | } |
| 106 | |
| 107 | /* Run the sb at s through do_scrub_chars and add the result to the sb |
| 108 | at ptr. */ |
| 109 | |
| 110 | void |
| 111 | sb_scrub_and_add_sb (sb *ptr, sb *s) |
| 112 | { |
| 113 | sb_to_scrub = s; |
| 114 | scrub_position = s->ptr; |
| 115 | |
| 116 | sb_check (ptr, s->len); |
| 117 | ptr->len += do_scrub_chars (scrub_from_sb, ptr->ptr + ptr->len, s->len); |
| 118 | |
| 119 | sb_to_scrub = 0; |
| 120 | scrub_position = 0; |
| 121 | } |
| 122 | |
| 123 | /* Make sure that the sb at ptr has room for another len characters, |
| 124 | and grow it if it doesn't. */ |
| 125 | |
| 126 | static void |
| 127 | sb_check (sb *ptr, size_t len) |
| 128 | { |
| 129 | size_t want = ptr->len + len; |
| 130 | |
| 131 | if (want > ptr->max) |
| 132 | { |
| 133 | size_t max; |
| 134 | |
| 135 | want += MALLOC_OVERHEAD + 1; |
| 136 | if ((ssize_t) want < 0) |
| 137 | as_fatal ("string buffer overflow"); |
| 138 | #if GCC_VERSION >= 3004 |
| 139 | max = (size_t) 1 << (CHAR_BIT * sizeof (want) |
| 140 | - (sizeof (want) <= sizeof (long) |
| 141 | ? __builtin_clzl ((long) want) |
| 142 | : __builtin_clzll ((long long) want))); |
| 143 | #else |
| 144 | max = 128; |
| 145 | while (want > max) |
| 146 | max <<= 1; |
| 147 | #endif |
| 148 | max -= MALLOC_OVERHEAD + 1; |
| 149 | ptr->max = max; |
| 150 | ptr->ptr = XRESIZEVEC (char, ptr->ptr, max + 1); |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | /* Make the sb at ptr point back to the beginning. */ |
| 155 | |
| 156 | void |
| 157 | sb_reset (sb *ptr) |
| 158 | { |
| 159 | ptr->len = 0; |
| 160 | } |
| 161 | |
| 162 | /* Add character c to the end of the sb at ptr. */ |
| 163 | |
| 164 | void |
| 165 | sb_add_char (sb *ptr, size_t c) |
| 166 | { |
| 167 | sb_check (ptr, 1); |
| 168 | ptr->ptr[ptr->len++] = c; |
| 169 | } |
| 170 | |
| 171 | /* Add null terminated string s to the end of sb at ptr. */ |
| 172 | |
| 173 | void |
| 174 | sb_add_string (sb *ptr, const char *s) |
| 175 | { |
| 176 | size_t len = strlen (s); |
| 177 | sb_check (ptr, len); |
| 178 | memcpy (ptr->ptr + ptr->len, s, len); |
| 179 | ptr->len += len; |
| 180 | } |
| 181 | |
| 182 | /* Add string at s of length len to sb at ptr */ |
| 183 | |
| 184 | void |
| 185 | sb_add_buffer (sb *ptr, const char *s, size_t len) |
| 186 | { |
| 187 | sb_check (ptr, len); |
| 188 | memcpy (ptr->ptr + ptr->len, s, len); |
| 189 | ptr->len += len; |
| 190 | } |
| 191 | |
| 192 | /* Write terminating NUL and return string. */ |
| 193 | |
| 194 | char * |
| 195 | sb_terminate (sb *in) |
| 196 | { |
| 197 | in->ptr[in->len] = 0; |
| 198 | return in->ptr; |
| 199 | } |
| 200 | |
| 201 | /* Start at the index idx into the string in sb at ptr and skip |
| 202 | whitespace. return the index of the first non whitespace character. */ |
| 203 | |
| 204 | size_t |
| 205 | sb_skip_white (size_t idx, sb *ptr) |
| 206 | { |
| 207 | while (idx < ptr->len |
| 208 | && (ptr->ptr[idx] == ' ' |
| 209 | || ptr->ptr[idx] == '\t')) |
| 210 | idx++; |
| 211 | return idx; |
| 212 | } |
| 213 | |
| 214 | /* Start at the index idx into the sb at ptr. skips whitespace, |
| 215 | a comma and any following whitespace. returns the index of the |
| 216 | next character. */ |
| 217 | |
| 218 | size_t |
| 219 | sb_skip_comma (size_t idx, sb *ptr) |
| 220 | { |
| 221 | while (idx < ptr->len |
| 222 | && (ptr->ptr[idx] == ' ' |
| 223 | || ptr->ptr[idx] == '\t')) |
| 224 | idx++; |
| 225 | |
| 226 | if (idx < ptr->len |
| 227 | && ptr->ptr[idx] == ',') |
| 228 | idx++; |
| 229 | |
| 230 | while (idx < ptr->len |
| 231 | && (ptr->ptr[idx] == ' ' |
| 232 | || ptr->ptr[idx] == '\t')) |
| 233 | idx++; |
| 234 | |
| 235 | return idx; |
| 236 | } |