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	niro	532	/*-
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	niro	1122	void pushstackmark(struct stackmark *mark, size_t len)
163	niro	532	{
164			mark->stackp = stackp;
165			mark->stacknxt = stacknxt;
166			mark->stacknleft = stacknleft;
167	niro	1122	grabstackblock(len);
168	niro	532	}
169
170	niro	1122	void setstackmark(struct stackmark *mark)
171			{
172			pushstackmark(mark, stacknxt == stackp->space && stackp != &stackbase);
173			}
174	niro	532
175	niro	1122
176	niro	532	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			}