Contents of /trunk/mkinitrd-magellan/klibc/usr/dash/memalloc.c
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Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
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Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
File MIME type: text/plain
File size: 7898 byte(s)
-import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
1 | /*- |
2 | * Copyright (c) 1991, 1993 |
3 | * The Regents of the University of California. All rights reserved. |
4 | * Copyright (c) 1997-2005 |
5 | * Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to Berkeley by |
8 | * Kenneth Almquist. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * 3. Neither the name of the University nor the names of its contributors |
19 | * may be used to endorse or promote products derived from this software |
20 | * without specific prior written permission. |
21 | * |
22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
32 | * SUCH DAMAGE. |
33 | */ |
34 | |
35 | #include <stdlib.h> |
36 | #include <unistd.h> |
37 | |
38 | #include "shell.h" |
39 | #include "output.h" |
40 | #include "memalloc.h" |
41 | #include "error.h" |
42 | #include "machdep.h" |
43 | #include "mystring.h" |
44 | #include "system.h" |
45 | |
46 | /* |
47 | * Like malloc, but returns an error when out of space. |
48 | */ |
49 | |
50 | pointer |
51 | ckmalloc(size_t nbytes) |
52 | { |
53 | pointer p; |
54 | |
55 | p = malloc(nbytes); |
56 | if (p == NULL) |
57 | sh_error("Out of space"); |
58 | return p; |
59 | } |
60 | |
61 | |
62 | /* |
63 | * Same for realloc. |
64 | */ |
65 | |
66 | pointer |
67 | ckrealloc(pointer p, size_t nbytes) |
68 | { |
69 | p = realloc(p, nbytes); |
70 | if (p == NULL) |
71 | sh_error("Out of space"); |
72 | return p; |
73 | } |
74 | |
75 | |
76 | /* |
77 | * Make a copy of a string in safe storage. |
78 | */ |
79 | |
80 | char * |
81 | savestr(const char *s) |
82 | { |
83 | char *p = strdup(s); |
84 | if (!p) |
85 | sh_error("Out of space"); |
86 | return p; |
87 | } |
88 | |
89 | |
90 | /* |
91 | * Parse trees for commands are allocated in lifo order, so we use a stack |
92 | * to make this more efficient, and also to avoid all sorts of exception |
93 | * handling code to handle interrupts in the middle of a parse. |
94 | * |
95 | * The size 504 was chosen because the Ultrix malloc handles that size |
96 | * well. |
97 | */ |
98 | |
99 | /* minimum size of a block */ |
100 | #define MINSIZE SHELL_ALIGN(504) |
101 | |
102 | struct stack_block { |
103 | struct stack_block *prev; |
104 | char space[MINSIZE]; |
105 | }; |
106 | |
107 | struct stack_block stackbase; |
108 | struct stack_block *stackp = &stackbase; |
109 | struct stackmark *markp; |
110 | char *stacknxt = stackbase.space; |
111 | size_t stacknleft = MINSIZE; |
112 | char *sstrend = stackbase.space + MINSIZE; |
113 | int herefd = -1; |
114 | |
115 | pointer |
116 | stalloc(size_t nbytes) |
117 | { |
118 | char *p; |
119 | size_t aligned; |
120 | |
121 | aligned = SHELL_ALIGN(nbytes); |
122 | if (aligned > stacknleft) { |
123 | size_t len; |
124 | size_t blocksize; |
125 | struct stack_block *sp; |
126 | |
127 | blocksize = aligned; |
128 | if (blocksize < MINSIZE) |
129 | blocksize = MINSIZE; |
130 | len = sizeof(struct stack_block) - MINSIZE + blocksize; |
131 | if (len < blocksize) |
132 | sh_error("Out of space"); |
133 | INTOFF; |
134 | sp = ckmalloc(len); |
135 | sp->prev = stackp; |
136 | stacknxt = sp->space; |
137 | stacknleft = blocksize; |
138 | sstrend = stacknxt + blocksize; |
139 | stackp = sp; |
140 | INTON; |
141 | } |
142 | p = stacknxt; |
143 | stacknxt += aligned; |
144 | stacknleft -= aligned; |
145 | return p; |
146 | } |
147 | |
148 | |
149 | void |
150 | stunalloc(pointer p) |
151 | { |
152 | #ifdef DEBUG |
153 | if (!p || (stacknxt < (char *)p) || ((char *)p < stackp->space)) { |
154 | write(2, "stunalloc\n", 10); |
155 | abort(); |
156 | } |
157 | #endif |
158 | stacknleft += stacknxt - (char *)p; |
159 | stacknxt = p; |
160 | } |
161 | |
162 | |
163 | |
164 | void |
165 | setstackmark(struct stackmark *mark) |
166 | { |
167 | mark->stackp = stackp; |
168 | mark->stacknxt = stacknxt; |
169 | mark->stacknleft = stacknleft; |
170 | mark->marknext = markp; |
171 | markp = mark; |
172 | } |
173 | |
174 | |
175 | void |
176 | popstackmark(struct stackmark *mark) |
177 | { |
178 | struct stack_block *sp; |
179 | |
180 | INTOFF; |
181 | markp = mark->marknext; |
182 | while (stackp != mark->stackp) { |
183 | sp = stackp; |
184 | stackp = sp->prev; |
185 | ckfree(sp); |
186 | } |
187 | stacknxt = mark->stacknxt; |
188 | stacknleft = mark->stacknleft; |
189 | sstrend = mark->stacknxt + mark->stacknleft; |
190 | INTON; |
191 | } |
192 | |
193 | |
194 | /* |
195 | * When the parser reads in a string, it wants to stick the string on the |
196 | * stack and only adjust the stack pointer when it knows how big the |
197 | * string is. Stackblock (defined in stack.h) returns a pointer to a block |
198 | * of space on top of the stack and stackblocklen returns the length of |
199 | * this block. Growstackblock will grow this space by at least one byte, |
200 | * possibly moving it (like realloc). Grabstackblock actually allocates the |
201 | * part of the block that has been used. |
202 | */ |
203 | |
204 | void |
205 | growstackblock(void) |
206 | { |
207 | size_t newlen; |
208 | |
209 | newlen = stacknleft * 2; |
210 | if (newlen < stacknleft) |
211 | sh_error("Out of space"); |
212 | if (newlen < 128) |
213 | newlen += 128; |
214 | |
215 | if (stacknxt == stackp->space && stackp != &stackbase) { |
216 | struct stack_block *oldstackp; |
217 | struct stackmark *xmark; |
218 | struct stack_block *sp; |
219 | struct stack_block *prevstackp; |
220 | size_t grosslen; |
221 | |
222 | INTOFF; |
223 | oldstackp = stackp; |
224 | sp = stackp; |
225 | prevstackp = sp->prev; |
226 | grosslen = newlen + sizeof(struct stack_block) - MINSIZE; |
227 | sp = ckrealloc((pointer)sp, grosslen); |
228 | sp->prev = prevstackp; |
229 | stackp = sp; |
230 | stacknxt = sp->space; |
231 | stacknleft = newlen; |
232 | sstrend = sp->space + newlen; |
233 | |
234 | /* |
235 | * Stack marks pointing to the start of the old block |
236 | * must be relocated to point to the new block |
237 | */ |
238 | xmark = markp; |
239 | while (xmark != NULL && xmark->stackp == oldstackp) { |
240 | xmark->stackp = stackp; |
241 | xmark->stacknxt = stacknxt; |
242 | xmark->stacknleft = stacknleft; |
243 | xmark = xmark->marknext; |
244 | } |
245 | INTON; |
246 | } else { |
247 | char *oldspace = stacknxt; |
248 | int oldlen = stacknleft; |
249 | char *p = stalloc(newlen); |
250 | |
251 | /* free the space we just allocated */ |
252 | stacknxt = memcpy(p, oldspace, oldlen); |
253 | stacknleft += newlen; |
254 | } |
255 | } |
256 | |
257 | void |
258 | grabstackblock(size_t len) |
259 | { |
260 | len = SHELL_ALIGN(len); |
261 | stacknxt += len; |
262 | stacknleft -= len; |
263 | } |
264 | |
265 | /* |
266 | * The following routines are somewhat easier to use than the above. |
267 | * The user declares a variable of type STACKSTR, which may be declared |
268 | * to be a register. The macro STARTSTACKSTR initializes things. Then |
269 | * the user uses the macro STPUTC to add characters to the string. In |
270 | * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is |
271 | * grown as necessary. When the user is done, she can just leave the |
272 | * string there and refer to it using stackblock(). Or she can allocate |
273 | * the space for it using grabstackstr(). If it is necessary to allow |
274 | * someone else to use the stack temporarily and then continue to grow |
275 | * the string, the user should use grabstack to allocate the space, and |
276 | * then call ungrabstr(p) to return to the previous mode of operation. |
277 | * |
278 | * USTPUTC is like STPUTC except that it doesn't check for overflow. |
279 | * CHECKSTACKSPACE can be called before USTPUTC to ensure that there |
280 | * is space for at least one character. |
281 | */ |
282 | |
283 | void * |
284 | growstackstr(void) |
285 | { |
286 | size_t len = stackblocksize(); |
287 | if (herefd >= 0 && len >= 1024) { |
288 | xwrite(herefd, stackblock(), len); |
289 | return stackblock(); |
290 | } |
291 | growstackblock(); |
292 | return stackblock() + len; |
293 | } |
294 | |
295 | /* |
296 | * Called from CHECKSTRSPACE. |
297 | */ |
298 | |
299 | char * |
300 | makestrspace(size_t newlen, char *p) |
301 | { |
302 | size_t len = p - stacknxt; |
303 | size_t size = stackblocksize(); |
304 | |
305 | for (;;) { |
306 | size_t nleft; |
307 | |
308 | size = stackblocksize(); |
309 | nleft = size - len; |
310 | if (nleft >= newlen) |
311 | break; |
312 | growstackblock(); |
313 | } |
314 | return stackblock() + len; |
315 | } |
316 | |
317 | char * |
318 | stnputs(const char *s, size_t n, char *p) |
319 | { |
320 | p = makestrspace(n, p); |
321 | p = mempcpy(p, s, n); |
322 | return p; |
323 | } |
324 | |
325 | char * |
326 | stputs(const char *s, char *p) |
327 | { |
328 | return stnputs(s, strlen(s), p); |
329 | } |