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;
struct stackmark *markp;
char *stacknxt = stackbase.space;
size_t stacknleft = MINSIZE;
char *sstrend = stackbase.space + MINSIZE;
int herefd = -1;

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
setstackmark(struct stackmark *mark)
{
	mark->stackp = stackp;
	mark->stacknxt = stacknxt;
	mark->stacknleft = stacknleft;
	mark->marknext = markp;
	markp = mark;
}


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

	INTOFF;
	markp = mark->marknext;
	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 stackmark *xmark;
		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;

		/*
		 * Stack marks pointing to the start of the old block
		 * must be relocated to point to the new block
		 */
		xmark = markp;
		while (xmark != NULL && xmark->stackp == oldstackp) {
			xmark->stackp = stackp;
			xmark->stacknxt = stacknxt;
			xmark->stacknleft = stacknleft;
			xmark = xmark->marknext;
		}
		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;
	}
}

void
grabstackblock(size_t len)
{
	len = SHELL_ALIGN(len);
	stacknxt += len;
	stacknleft -= len;
}

/*
 * 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();
	if (herefd >= 0 && len >= 1024) {
		xwrite(herefd, stackblock(), len);
		return stackblock();
	}
	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			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			}