usr/dash/memalloc.c

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1997-2005
 *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stdlib.h>
#include <unistd.h>

#include "shell.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "machdep.h"
#include "mystring.h"
#include "system.h"

/*
 * Like malloc, but returns an error when out of space.
 */

pointer
ckmalloc(size_t nbytes)
{
	pointer p;

	p = malloc(nbytes);
	if (p == NULL)
		sh_error("Out of space");
	return p;
}


/*
 * Same for realloc.
 */

pointer
ckrealloc(pointer p, size_t nbytes)
{
	p = realloc(p, nbytes);
	if (p == NULL)
		sh_error("Out of space");
	return p;
}


/*
 * Make a copy of a string in safe storage.
 */

char *
savestr(const char *s)
{
	char *p = strdup(s);
	if (!p)
		sh_error("Out of space");
	return p;
}


/*
 * Parse trees for commands are allocated in lifo order, so we use a stack
 * to make this more efficient, and also to avoid all sorts of exception
 * handling code to handle interrupts in the middle of a parse.
 *
 * The size 504 was chosen because the Ultrix malloc handles that size
 * well.
 */

/* minimum size of a block */
#define MINSIZE SHELL_ALIGN(504)

struct stack_block {
	struct stack_block *prev;
	char space[MINSIZE];
};

struct stack_block stackbase;
struct stack_block *stackp = &stackbase;
char *stacknxt = stackbase.space;
size_t stacknleft = MINSIZE;
char *sstrend = stackbase.space + MINSIZE;

pointer
stalloc(size_t nbytes)
{
	char *p;
	size_t aligned;

	aligned = SHELL_ALIGN(nbytes);
	if (aligned > stacknleft) {
		size_t len;
		size_t blocksize;
		struct stack_block *sp;

		blocksize = aligned;
		if (blocksize < MINSIZE)
			blocksize = MINSIZE;
		len = sizeof(struct stack_block) - MINSIZE + blocksize;
		if (len < blocksize)
			sh_error("Out of space");
		INTOFF;
		sp = ckmalloc(len);
		sp->prev = stackp;
		stacknxt = sp->space;
		stacknleft = blocksize;
		sstrend = stacknxt + blocksize;
		stackp = sp;
		INTON;
	}
	p = stacknxt;
	stacknxt += aligned;
	stacknleft -= aligned;
	return p;
}


void
stunalloc(pointer p)
{
#ifdef DEBUG
	if (!p || (stacknxt < (char *)p) || ((char *)p < stackp->space)) {
		write(2, "stunalloc\n", 10);
		abort();
	}
#endif
	stacknleft += stacknxt - (char *)p;
	stacknxt = p;
}


void pushstackmark(struct stackmark *mark, size_t len)
{
	mark->stackp = stackp;
	mark->stacknxt = stacknxt;
	mark->stacknleft = stacknleft;
	grabstackblock(len);
}

void setstackmark(struct stackmark *mark)
{
	pushstackmark(mark, stacknxt == stackp->space && stackp != &stackbase);
}


void
popstackmark(struct stackmark *mark)
{
	struct stack_block *sp;

	INTOFF;
	while (stackp != mark->stackp) {
		sp = stackp;
		stackp = sp->prev;
		ckfree(sp);
	}
	stacknxt = mark->stacknxt;
	stacknleft = mark->stacknleft;
	sstrend = mark->stacknxt + mark->stacknleft;
	INTON;
}


/*
 * When the parser reads in a string, it wants to stick the string on the
 * stack and only adjust the stack pointer when it knows how big the
 * string is.  Stackblock (defined in stack.h) returns a pointer to a block
 * of space on top of the stack and stackblocklen returns the length of
 * this block.  Growstackblock will grow this space by at least one byte,
 * possibly moving it (like realloc).  Grabstackblock actually allocates the
 * part of the block that has been used.
 */

void
growstackblock(void)
{
	size_t newlen;

 	newlen = stacknleft * 2;
	if (newlen < stacknleft)
		sh_error("Out of space");
	if (newlen < 128)
		newlen += 128;

	if (stacknxt == stackp->space && stackp != &stackbase) {
		struct stack_block *oldstackp;
		struct stack_block *sp;
		struct stack_block *prevstackp;
		size_t grosslen;

		INTOFF;
		oldstackp = stackp;
		sp = stackp;
		prevstackp = sp->prev;
		grosslen = newlen + sizeof(struct stack_block) - MINSIZE;
		sp = ckrealloc((pointer)sp, grosslen);
		sp->prev = prevstackp;
		stackp = sp;
		stacknxt = sp->space;
		stacknleft = newlen;
		sstrend = sp->space + newlen;
		INTON;
	} else {
		char *oldspace = stacknxt;
		int oldlen = stacknleft;
		char *p = stalloc(newlen);

		/* free the space we just allocated */
		stacknxt = memcpy(p, oldspace, oldlen);
		stacknleft += newlen;
	}
}

/*
 * The following routines are somewhat easier to use than the above.
 * The user declares a variable of type STACKSTR, which may be declared
 * to be a register.  The macro STARTSTACKSTR initializes things.  Then
 * the user uses the macro STPUTC to add characters to the string.  In
 * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
 * grown as necessary.  When the user is done, she can just leave the
 * string there and refer to it using stackblock().  Or she can allocate
 * the space for it using grabstackstr().  If it is necessary to allow
 * someone else to use the stack temporarily and then continue to grow
 * the string, the user should use grabstack to allocate the space, and
 * then call ungrabstr(p) to return to the previous mode of operation.
 *
 * USTPUTC is like STPUTC except that it doesn't check for overflow.
 * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
 * is space for at least one character.
 */

void *
growstackstr(void)
{
	size_t len = stackblocksize();
	growstackblock();
	return stackblock() + len;
}

/*
 * Called from CHECKSTRSPACE.
 */

char *
makestrspace(size_t newlen, char *p)
{
	size_t len = p - stacknxt;
	size_t size = stackblocksize();

	for (;;) {
		size_t nleft;

		size = stackblocksize();
		nleft = size - len;
		if (nleft >= newlen)
			break;
		growstackblock();
	}
	return stackblock() + len;
}

char *
stnputs(const char *s, size_t n, char *p)
{
	p = makestrspace(n, p);
	p = mempcpy(p, s, n);
	return p;
}

char *
stputs(const char *s, char *p)
{
	return stnputs(s, strlen(s), p);
}
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	char *stacknxt = stackbase.space;
110	size_t stacknleft = MINSIZE;
111	char *sstrend = stackbase.space + MINSIZE;
112
113	pointer
114	stalloc(size_t nbytes)
115	{
116	char *p;
117	size_t aligned;
118
119	aligned = SHELL_ALIGN(nbytes);
120	if (aligned > stacknleft) {
121	size_t len;
122	size_t blocksize;
123	struct stack_block *sp;
124
125	blocksize = aligned;
126	if (blocksize < MINSIZE)
127	blocksize = MINSIZE;
128	len = sizeof(struct stack_block) - MINSIZE + blocksize;
129	if (len < blocksize)
130	sh_error("Out of space");
131	INTOFF;
132	sp = ckmalloc(len);
133	sp->prev = stackp;
134	stacknxt = sp->space;
135	stacknleft = blocksize;
136	sstrend = stacknxt + blocksize;
137	stackp = sp;
138	INTON;
139	}
140	p = stacknxt;
141	stacknxt += aligned;
142	stacknleft -= aligned;
143	return p;
144	}
145
146
147	void
148	stunalloc(pointer p)
149	{
150	#ifdef DEBUG
151	if (!p \|\| (stacknxt < (char )p) \|\| ((char )p < stackp->space)) {
152	write(2, "stunalloc\n", 10);
153	abort();
154	}
155	#endif
156	stacknleft += stacknxt - (char *)p;
157	stacknxt = p;
158	}
159
160
161
162	void pushstackmark(struct stackmark *mark, size_t len)
163	{
164	mark->stackp = stackp;
165	mark->stacknxt = stacknxt;
166	mark->stacknleft = stacknleft;
167	grabstackblock(len);
168	}
169
170	void setstackmark(struct stackmark *mark)
171	{
172	pushstackmark(mark, stacknxt == stackp->space && stackp != &stackbase);
173	}
174
175
176	void
177	popstackmark(struct stackmark *mark)
178	{
179	struct stack_block *sp;
180
181	INTOFF;
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 stack_block *sp;
218	struct stack_block *prevstackp;
219	size_t grosslen;
220
221	INTOFF;
222	oldstackp = stackp;
223	sp = stackp;
224	prevstackp = sp->prev;
225	grosslen = newlen + sizeof(struct stack_block) - MINSIZE;
226	sp = ckrealloc((pointer)sp, grosslen);
227	sp->prev = prevstackp;
228	stackp = sp;
229	stacknxt = sp->space;
230	stacknleft = newlen;
231	sstrend = sp->space + newlen;
232	INTON;
233	} else {
234	char *oldspace = stacknxt;
235	int oldlen = stacknleft;
236	char *p = stalloc(newlen);
237
238	/* free the space we just allocated */
239	stacknxt = memcpy(p, oldspace, oldlen);
240	stacknleft += newlen;
241	}
242	}
243
244	/*
245	* The following routines are somewhat easier to use than the above.
246	* The user declares a variable of type STACKSTR, which may be declared
247	* to be a register. The macro STARTSTACKSTR initializes things. Then
248	* the user uses the macro STPUTC to add characters to the string. In
249	* effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
250	* grown as necessary. When the user is done, she can just leave the
251	* string there and refer to it using stackblock(). Or she can allocate
252	* the space for it using grabstackstr(). If it is necessary to allow
253	* someone else to use the stack temporarily and then continue to grow
254	* the string, the user should use grabstack to allocate the space, and
255	* then call ungrabstr(p) to return to the previous mode of operation.
256	*
257	* USTPUTC is like STPUTC except that it doesn't check for overflow.
258	* CHECKSTACKSPACE can be called before USTPUTC to ensure that there
259	* is space for at least one character.
260	*/
261
262	void *
263	growstackstr(void)
264	{
265	size_t len = stackblocksize();
266	growstackblock();
267	return stackblock() + len;
268	}
269
270	/*
271	* Called from CHECKSTRSPACE.
272	*/
273
274	char *
275	makestrspace(size_t newlen, char *p)
276	{
277	size_t len = p - stacknxt;
278	size_t size = stackblocksize();
279
280	for (;;) {
281	size_t nleft;
282
283	size = stackblocksize();
284	nleft = size - len;
285	if (nleft >= newlen)
286	break;
287	growstackblock();
288	}
289	return stackblock() + len;
290	}
291
292	char *
293	stnputs(const char s, size_t n, char p)
294	{
295	p = makestrspace(n, p);
296	p = mempcpy(p, s, n);
297	return p;
298	}
299
300	char *
301	stputs(const char s, char p)
302	{
303	return stnputs(s, strlen(s), p);
304	}