blob: d8e4413d69dae418f113ec1f33ee46717a41d000 [file] [log] [blame]
/*-
* 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 *sp;
struct stack_block *prevstackp;
size_t grosslen;
INTOFF;
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;
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);
}