1 /* $NetBSD: memalloc.c,v 1.28 2003/08/07 09:05:34 agc Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. 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 #if 0
36 #ifndef lint
37 static char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95";
38 #else
39 __RCSID("$NetBSD: memalloc.c,v 1.28 2003/08/07 09:05:34 agc Exp $");
40 #endif /* not lint */
41 #endif
42
43 #include <stdlib.h>
44
45 #include "shell.h"
46 #include "output.h"
47 #include "memalloc.h"
48 #include "error.h"
49 #include "machdep.h"
50 #include "mystring.h"
51 #include "shinstance.h"
52
53 /*
54 * Like malloc, but returns an error when out of space.
55 */
56
57 pointer
ckmalloc(shinstance * psh,size_t nbytes)58 ckmalloc(shinstance *psh, size_t nbytes)
59 {
60 pointer p;
61
62 p = sh_malloc(psh, nbytes);
63 if (p == NULL)
64 error(psh, "Out of space");
65 return p;
66 }
67
68
69 /*
70 * Same for realloc.
71 */
72
73 pointer
ckrealloc(struct shinstance * psh,pointer p,size_t nbytes)74 ckrealloc(struct shinstance *psh, pointer p, size_t nbytes)
75 {
76 p = sh_realloc(psh, p, nbytes);
77 if (p == NULL)
78 error(psh, "Out of space");
79 return p;
80 }
81
82
83 /*
84 * Make a copy of a string in safe storage.
85 */
86
87 char *
savestr(struct shinstance * psh,const char * s)88 savestr(struct shinstance *psh, const char *s)
89 {
90 char *p;
91 size_t len = strlen(s);
92
93 p = ckmalloc(psh, len + 1);
94 memcpy(p, s, len + 1);
95 return p;
96 }
97
98
99 /*
100 * Parse trees for commands are allocated in lifo order, so we use a stack
101 * to make this more efficient, and also to avoid all sorts of exception
102 * handling code to handle interrupts in the middle of a parse.
103 *
104 * The size 504 was chosen because the Ultrix malloc handles that size
105 * well.
106 */
107
108 //#define MINSIZE 504 /* minimum size of a block */
109
110 //struct stack_block {
111 // struct stack_block *prev;
112 // char space[MINSIZE];
113 //};
114
115 //struct stack_block stackbase;
116 //struct stack_block *stackp = &stackbase;
117 //struct stackmark *markp;
118 //char *stacknxt = stackbase.space;
119 //int stacknleft = MINSIZE;
120 //int sstrnleft;
121 //int herefd = -1;
122
123 pointer
stalloc(shinstance * psh,size_t nbytes)124 stalloc(shinstance *psh, size_t nbytes)
125 {
126 char *p;
127
128 nbytes = SHELL_ALIGN(nbytes);
129 if (nbytes > (size_t)psh->stacknleft || psh->stacknleft < 0) {
130 size_t blocksize;
131 struct stack_block *sp;
132
133 blocksize = nbytes;
134 if (blocksize < MINSIZE)
135 blocksize = MINSIZE;
136 INTOFF;
137 sp = ckmalloc(psh, sizeof(struct stack_block) - MINSIZE + blocksize);
138 sp->prev = psh->stackp;
139 psh->stacknxt = sp->space;
140 psh->stacknleft = (int)blocksize;
141 psh->stackp = sp;
142 INTON;
143 }
144 p = psh->stacknxt;
145 psh->stacknxt += nbytes;
146 psh->stacknleft -= (int)nbytes;
147 return p;
148 }
149
150
151 void
stunalloc(shinstance * psh,pointer p)152 stunalloc(shinstance *psh, pointer p)
153 {
154 if (p == NULL) { /*DEBUG */
155 shfile_write(&psh->fdtab, 2, "stunalloc\n", 10);
156 sh_abort(psh);
157 }
158 psh->stacknleft += (int)(psh->stacknxt - (char *)p);
159 psh->stacknxt = p;
160 }
161
162
163
164 void
setstackmark(shinstance * psh,struct stackmark * mark)165 setstackmark(shinstance *psh, struct stackmark *mark)
166 {
167 mark->stackp = psh->stackp;
168 mark->stacknxt = psh->stacknxt;
169 mark->stacknleft = psh->stacknleft;
170 mark->marknext = psh->markp;
171 psh->markp = mark;
172 }
173
174
175 void
popstackmark(shinstance * psh,struct stackmark * mark)176 popstackmark(shinstance *psh, struct stackmark *mark)
177 {
178 struct stack_block *sp;
179
180 INTOFF;
181 psh->markp = mark->marknext;
182 while (psh->stackp != mark->stackp) {
183 sp = psh->stackp;
184 psh->stackp = sp->prev;
185 ckfree(psh, sp);
186 }
187 psh->stacknxt = mark->stacknxt;
188 psh->stacknleft = mark->stacknleft;
189 INTON;
190 }
191
192
193 /*
194 * When the parser reads in a string, it wants to stick the string on the
195 * stack and only adjust the stack pointer when it knows how big the
196 * string is. Stackblock (defined in stack.h) returns a pointer to a block
197 * of space on top of the stack and stackblocklen returns the length of
198 * this block. Growstackblock will grow this space by at least one byte,
199 * possibly moving it (like realloc). Grabstackblock actually allocates the
200 * part of the block that has been used.
201 */
202
203 void
growstackblock(shinstance * psh)204 growstackblock(shinstance *psh)
205 {
206 int newlen = SHELL_ALIGN(psh->stacknleft * 2 + 100);
207
208 if (psh->stacknxt == psh->stackp->space && psh->stackp != &psh->stackbase) {
209 struct stack_block *oldstackp;
210 struct stackmark *xmark;
211 struct stack_block *sp;
212
213 INTOFF;
214 oldstackp = psh->stackp;
215 sp = psh->stackp;
216 psh->stackp = sp->prev;
217 sp = ckrealloc(psh, (pointer)sp,
218 sizeof(struct stack_block) - MINSIZE + newlen);
219 sp->prev = psh->stackp;
220 psh->stackp = sp;
221 psh->stacknxt = sp->space;
222 psh->stacknleft = newlen;
223
224 /*
225 * Stack marks pointing to the start of the old block
226 * must be relocated to point to the new block
227 */
228 xmark = psh->markp;
229 while (xmark != NULL && xmark->stackp == oldstackp) {
230 xmark->stackp = psh->stackp;
231 xmark->stacknxt = psh->stacknxt;
232 xmark->stacknleft = psh->stacknleft;
233 xmark = xmark->marknext;
234 }
235 INTON;
236 } else {
237 char *oldspace = psh->stacknxt;
238 int oldlen = psh->stacknleft;
239 char *p = stalloc(psh, newlen);
240
241 (void)memcpy(p, oldspace, oldlen);
242 psh->stacknxt = p; /* free the space */
243 psh->stacknleft += newlen; /* we just allocated */
244 }
245 }
246
247 void
grabstackblock(shinstance * psh,int len)248 grabstackblock(shinstance *psh, int len)
249 {
250 len = SHELL_ALIGN(len);
251 psh->stacknxt += len;
252 psh->stacknleft -= len;
253 }
254
255 /*
256 * The following routines are somewhat easier to use than the above.
257 * The user declares a variable of type STACKSTR, which may be declared
258 * to be a register. The macro STARTSTACKSTR initializes things. Then
259 * the user uses the macro STPUTC to add characters to the string. In
260 * effect, STPUTC(psh, c, p) is the same as *p++ = c except that the stack is
261 * grown as necessary. When the user is done, she can just leave the
262 * string there and refer to it using stackblock(psh). Or she can allocate
263 * the space for it using grabstackstr(). If it is necessary to allow
264 * someone else to use the stack temporarily and then continue to grow
265 * the string, the user should use grabstack to allocate the space, and
266 * then call ungrabstr(p) to return to the previous mode of operation.
267 *
268 * USTPUTC is like STPUTC except that it doesn't check for overflow.
269 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
270 * is space for at least one character.
271 */
272
273 char *
growstackstr(shinstance * psh)274 growstackstr(shinstance *psh)
275 {
276 int len = stackblocksize(psh);
277 if (psh->herefd >= 0 && len >= 1024) {
278 xwrite(psh, psh->herefd, stackblock(psh), len);
279 psh->sstrnleft = len - 1;
280 return stackblock(psh);
281 }
282 growstackblock(psh);
283 psh->sstrnleft = stackblocksize(psh) - len - 1;
284 return stackblock(psh) + len;
285 }
286
287 /*
288 * Called from CHECKSTRSPACE.
289 */
290
291 char *
makestrspace(shinstance * psh)292 makestrspace(shinstance *psh)
293 {
294 int len = stackblocksize(psh) - psh->sstrnleft;
295 growstackblock(psh);
296 psh->sstrnleft = stackblocksize(psh) - len;
297 return stackblock(psh) + len;
298 }
299
300 void
ungrabstackstr(shinstance * psh,char * s,char * p)301 ungrabstackstr(shinstance *psh, char *s, char *p)
302 {
303 psh->stacknleft += (int)(psh->stacknxt - s);
304 psh->stacknxt = s;
305 psh->sstrnleft = (int)(psh->stacknleft - (p - s));
306
307 }
308