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1 | /*- |
2 | * Copyright (c) 1991 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Kenneth Almquist. | |
7 | * | |
af359dea C |
8 | * Redistribution and use in source and binary forms, with or without |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. All advertising materials mentioning features or use of this software | |
17 | * must display the following acknowledgement: | |
18 | * This product includes software developed by the University of | |
19 | * California, Berkeley and its contributors. | |
20 | * 4. Neither the name of the University nor the names of its contributors | |
21 | * may be used to endorse or promote products derived from this software | |
22 | * without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
34 | * SUCH DAMAGE. | |
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35 | */ |
36 | ||
37 | #ifndef lint | |
af359dea | 38 | static char sccsid[] = "@(#)memalloc.c 5.2 (Berkeley) 3/13/91"; |
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39 | #endif /* not lint */ |
40 | ||
41 | #include "shell.h" | |
42 | #include "output.h" | |
43 | #include "memalloc.h" | |
44 | #include "error.h" | |
45 | #include "machdep.h" | |
46 | #include "mystring.h" | |
47 | ||
48 | /* | |
49 | * Like malloc, but returns an error when out of space. | |
50 | */ | |
51 | ||
52 | pointer | |
53 | ckmalloc(nbytes) { | |
54 | register pointer p; | |
55 | pointer malloc(); | |
56 | ||
57 | if ((p = malloc(nbytes)) == NULL) | |
58 | error("Out of space"); | |
59 | return p; | |
60 | } | |
61 | ||
62 | ||
63 | /* | |
64 | * Same for realloc. | |
65 | */ | |
66 | ||
67 | pointer | |
68 | ckrealloc(p, nbytes) | |
69 | register pointer p; | |
70 | { | |
71 | pointer realloc(); | |
72 | ||
73 | if ((p = realloc(p, nbytes)) == NULL) | |
74 | error("Out of space"); | |
75 | return p; | |
76 | } | |
77 | ||
78 | ||
79 | /* | |
80 | * Make a copy of a string in safe storage. | |
81 | */ | |
82 | ||
83 | char * | |
84 | savestr(s) | |
85 | char *s; | |
86 | { | |
87 | register char *p; | |
88 | ||
89 | p = ckmalloc(strlen(s) + 1); | |
90 | scopy(s, p); | |
91 | return p; | |
92 | } | |
93 | ||
94 | ||
95 | /* | |
96 | * Parse trees for commands are allocated in lifo order, so we use a stack | |
97 | * to make this more efficient, and also to avoid all sorts of exception | |
98 | * handling code to handle interrupts in the middle of a parse. | |
99 | * | |
100 | * The size 504 was chosen because the Ultrix malloc handles that size | |
101 | * well. | |
102 | */ | |
103 | ||
104 | #define MINSIZE 504 /* minimum size of a block */ | |
105 | ||
106 | ||
107 | struct stack_block { | |
108 | struct stack_block *prev; | |
109 | char space[MINSIZE]; | |
110 | }; | |
111 | ||
112 | struct stack_block stackbase; | |
113 | struct stack_block *stackp = &stackbase; | |
114 | char *stacknxt = stackbase.space; | |
115 | int stacknleft = MINSIZE; | |
116 | int sstrnleft; | |
117 | int herefd = -1; | |
118 | ||
119 | ||
120 | ||
121 | pointer | |
122 | stalloc(nbytes) { | |
123 | register char *p; | |
124 | ||
125 | nbytes = ALIGN(nbytes); | |
126 | if (nbytes > stacknleft) { | |
127 | int blocksize; | |
128 | struct stack_block *sp; | |
129 | ||
130 | blocksize = nbytes; | |
131 | if (blocksize < MINSIZE) | |
132 | blocksize = MINSIZE; | |
133 | INTOFF; | |
134 | sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); | |
135 | sp->prev = stackp; | |
136 | stacknxt = sp->space; | |
137 | stacknleft = blocksize; | |
138 | stackp = sp; | |
139 | INTON; | |
140 | } | |
141 | p = stacknxt; | |
142 | stacknxt += nbytes; | |
143 | stacknleft -= nbytes; | |
144 | return p; | |
145 | } | |
146 | ||
147 | ||
148 | void | |
149 | stunalloc(p) | |
150 | pointer p; | |
151 | { | |
152 | if (p == NULL) { /*DEBUG */ | |
153 | write(2, "stunalloc\n", 10); | |
154 | abort(); | |
155 | } | |
156 | stacknleft += stacknxt - (char *)p; | |
157 | stacknxt = p; | |
158 | } | |
159 | ||
160 | ||
161 | ||
162 | void | |
163 | setstackmark(mark) | |
164 | struct stackmark *mark; | |
165 | { | |
166 | mark->stackp = stackp; | |
167 | mark->stacknxt = stacknxt; | |
168 | mark->stacknleft = stacknleft; | |
169 | } | |
170 | ||
171 | ||
172 | void | |
173 | popstackmark(mark) | |
174 | struct stackmark *mark; | |
175 | { | |
176 | struct stack_block *sp; | |
177 | ||
178 | INTOFF; | |
179 | while (stackp != mark->stackp) { | |
180 | sp = stackp; | |
181 | stackp = sp->prev; | |
182 | ckfree(sp); | |
183 | } | |
184 | stacknxt = mark->stacknxt; | |
185 | stacknleft = mark->stacknleft; | |
186 | INTON; | |
187 | } | |
188 | ||
189 | ||
190 | /* | |
191 | * When the parser reads in a string, it wants to stick the string on the | |
192 | * stack and only adjust the stack pointer when it knows how big the | |
193 | * string is. Stackblock (defined in stack.h) returns a pointer to a block | |
194 | * of space on top of the stack and stackblocklen returns the length of | |
195 | * this block. Growstackblock will grow this space by at least one byte, | |
196 | * possibly moving it (like realloc). Grabstackblock actually allocates the | |
197 | * part of the block that has been used. | |
198 | */ | |
199 | ||
200 | void | |
201 | growstackblock() { | |
202 | char *p; | |
203 | int newlen = stacknleft * 2 + 100; | |
204 | char *oldspace = stacknxt; | |
205 | int oldlen = stacknleft; | |
206 | struct stack_block *sp; | |
207 | ||
ddba57cd | 208 | if (stacknxt == stackp->space && stackp != &stackbase) { |
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209 | INTOFF; |
210 | sp = stackp; | |
211 | stackp = sp->prev; | |
212 | sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); | |
213 | sp->prev = stackp; | |
214 | stackp = sp; | |
215 | stacknxt = sp->space; | |
216 | stacknleft = newlen; | |
217 | INTON; | |
218 | } else { | |
219 | p = stalloc(newlen); | |
220 | bcopy(oldspace, p, oldlen); | |
221 | stacknxt = p; /* free the space */ | |
222 | stacknleft += newlen; /* we just allocated */ | |
223 | } | |
224 | } | |
225 | ||
226 | ||
227 | ||
228 | void | |
229 | grabstackblock(len) { | |
230 | len = ALIGN(len); | |
231 | stacknxt += len; | |
232 | stacknleft -= len; | |
233 | } | |
234 | ||
235 | ||
236 | ||
237 | /* | |
238 | * The following routines are somewhat easier to use that the above. | |
239 | * The user declares a variable of type STACKSTR, which may be declared | |
240 | * to be a register. The macro STARTSTACKSTR initializes things. Then | |
241 | * the user uses the macro STPUTC to add characters to the string. In | |
242 | * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is | |
243 | * grown as necessary. When the user is done, she can just leave the | |
244 | * string there and refer to it using stackblock(). Or she can allocate | |
245 | * the space for it using grabstackstr(). If it is necessary to allow | |
246 | * someone else to use the stack temporarily and then continue to grow | |
247 | * the string, the user should use grabstack to allocate the space, and | |
248 | * then call ungrabstr(p) to return to the previous mode of operation. | |
249 | * | |
250 | * USTPUTC is like STPUTC except that it doesn't check for overflow. | |
251 | * CHECKSTACKSPACE can be called before USTPUTC to ensure that there | |
252 | * is space for at least one character. | |
253 | */ | |
254 | ||
255 | ||
256 | char * | |
257 | growstackstr() { | |
258 | int len = stackblocksize(); | |
ddba57cd | 259 | if (herefd >= 0 && len >= 1024) { |
a7251d1d KB |
260 | xwrite(herefd, stackblock(), len); |
261 | sstrnleft = len - 1; | |
262 | return stackblock(); | |
263 | } | |
264 | growstackblock(); | |
265 | sstrnleft = stackblocksize() - len - 1; | |
266 | return stackblock() + len; | |
267 | } | |
268 | ||
269 | ||
270 | /* | |
271 | * Called from CHECKSTRSPACE. | |
272 | */ | |
273 | ||
274 | char * | |
275 | makestrspace() { | |
276 | int len = stackblocksize() - sstrnleft; | |
277 | growstackblock(); | |
278 | sstrnleft = stackblocksize() - len; | |
279 | return stackblock() + len; | |
280 | } | |
281 | ||
282 | ||
283 | ||
284 | void | |
285 | ungrabstackstr(s, p) | |
286 | char *s; | |
287 | char *p; | |
288 | { | |
289 | stacknleft += stacknxt - s; | |
290 | stacknxt = s; | |
291 | sstrnleft = stacknleft - (p - s); | |
292 | } |