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author | 2021-05-09 14:20:58 -0400 | |
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committer | 2021-05-09 14:20:58 -0400 | |
commit | 5fd83771641d15c418f747bd343ba6738d3875f7 (patch) | |
tree | 5abf0f78f680d9837dbd93d4d4c3933bb7509599 /shell_cmds/sh/memalloc.c | |
download | apple_cmds-5fd83771641d15c418f747bd343ba6738d3875f7.tar.gz apple_cmds-5fd83771641d15c418f747bd343ba6738d3875f7.tar.zst apple_cmds-5fd83771641d15c418f747bd343ba6738d3875f7.zip |
Import macOS userland
adv_cmds-176
basic_cmds-55
bootstrap_cmds-116.100.1
developer_cmds-66
diskdev_cmds-667.40.1
doc_cmds-53.60.1
file_cmds-321.40.3
mail_cmds-35
misc_cmds-34
network_cmds-606.40.1
patch_cmds-17
remote_cmds-63
shell_cmds-216.60.1
system_cmds-880.60.2
text_cmds-106
Diffstat (limited to 'shell_cmds/sh/memalloc.c')
-rw-r--r-- | shell_cmds/sh/memalloc.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/shell_cmds/sh/memalloc.c b/shell_cmds/sh/memalloc.c new file mode 100644 index 0000000..7b5f325 --- /dev/null +++ b/shell_cmds/sh/memalloc.c @@ -0,0 +1,344 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1991, 1993 + * The Regents of the University of California. 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. + */ + +#ifndef lint +#if 0 +static char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; +#endif +#endif /* not lint */ +#include <sys/cdefs.h> +__FBSDID("$FreeBSD: head/bin/sh/memalloc.c 326025 2017-11-20 19:49:47Z pfg $"); + +#include <sys/param.h> +#include "shell.h" +#include "output.h" +#include "memalloc.h" +#include "error.h" +#include "mystring.h" +#include "expand.h" +#include <stdlib.h> +#include <unistd.h> + +/* + * Like malloc, but returns an error when out of space. + */ + +pointer +ckmalloc(size_t nbytes) +{ + pointer p; + + INTOFF; + p = malloc(nbytes); + INTON; + if (p == NULL) + error("Out of space"); + return p; +} + + +/* + * Same for realloc. + */ + +pointer +ckrealloc(pointer p, int nbytes) +{ + INTOFF; + p = realloc(p, nbytes); + INTON; + if (p == NULL) + error("Out of space"); + return p; +} + +void +ckfree(pointer p) +{ + INTOFF; + free(p); + INTON; +} + + +/* + * Make a copy of a string in safe storage. + */ + +char * +savestr(const char *s) +{ + char *p; + size_t len; + + len = strlen(s); + p = ckmalloc(len + 1); + memcpy(p, s, len + 1); + 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 496 was chosen because with 16-byte alignment the total size + * for the allocated block is 512. + */ + +#define MINSIZE 496 /* minimum size of a block. */ + + +struct stack_block { + struct stack_block *prev; + /* Data follows */ +}; +#define SPACE(sp) ((char*)(sp) + ALIGN(sizeof(struct stack_block))) + +static struct stack_block *stackp; +char *stacknxt; +int stacknleft; +char *sstrend; + + +static void +stnewblock(int nbytes) +{ + struct stack_block *sp; + int allocsize; + + if (nbytes < MINSIZE) + nbytes = MINSIZE; + + allocsize = ALIGN(sizeof(struct stack_block)) + ALIGN(nbytes); + + INTOFF; + sp = ckmalloc(allocsize); + sp->prev = stackp; + stacknxt = SPACE(sp); + stacknleft = allocsize - (stacknxt - (char*)sp); + sstrend = stacknxt + stacknleft; + stackp = sp; + INTON; +} + + +pointer +stalloc(int nbytes) +{ + char *p; + + nbytes = ALIGN(nbytes); + if (nbytes > stacknleft) + stnewblock(nbytes); + p = stacknxt; + stacknxt += nbytes; + stacknleft -= nbytes; + return p; +} + + +void +stunalloc(pointer p) +{ + if (p == NULL) { /*DEBUG */ + write(STDERR_FILENO, "stunalloc\n", 10); + abort(); + } + stacknleft += stacknxt - (char *)p; + stacknxt = p; +} + + +char * +stsavestr(const char *s) +{ + char *p; + size_t len; + + len = strlen(s); + p = stalloc(len + 1); + memcpy(p, s, len + 1); + return p; +} + + +void +setstackmark(struct stackmark *mark) +{ + mark->stackp = stackp; + mark->stacknxt = stacknxt; + mark->stacknleft = stacknleft; + /* Ensure this block stays in place. */ + if (stackp != NULL && stacknxt == SPACE(stackp)) + stalloc(1); +} + + +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 = stacknxt + 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. + */ + +static void +growstackblock(int min) +{ + char *p; + int newlen; + char *oldspace; + int oldlen; + struct stack_block *sp; + struct stack_block *oldstackp; + + if (min < stacknleft) + min = stacknleft; + if ((unsigned int)min >= + INT_MAX / 2 - ALIGN(sizeof(struct stack_block))) + error("Out of space"); + min += stacknleft; + min += ALIGN(sizeof(struct stack_block)); + newlen = 512; + while (newlen < min) + newlen <<= 1; + oldspace = stacknxt; + oldlen = stacknleft; + + if (stackp != NULL && stacknxt == SPACE(stackp)) { + INTOFF; + oldstackp = stackp; + stackp = oldstackp->prev; + sp = ckrealloc((pointer)oldstackp, newlen); + sp->prev = stackp; + stackp = sp; + stacknxt = SPACE(sp); + stacknleft = newlen - (stacknxt - (char*)sp); + sstrend = stacknxt + stacknleft; + INTON; + } else { + newlen -= ALIGN(sizeof(struct stack_block)); + p = stalloc(newlen); + if (oldlen != 0) + memcpy(p, oldspace, oldlen); + stunalloc(p); + } +} + + + +/* + * The following routines are somewhat easier to use that 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. + */ + +static char * +growstrstackblock(int n, int min) +{ + growstackblock(min); + return stackblock() + n; +} + +char * +growstackstr(void) +{ + int len; + + len = stackblocksize(); + return (growstrstackblock(len, 0)); +} + + +/* + * Called from CHECKSTRSPACE. + */ + +char * +makestrspace(int min, char *p) +{ + int len; + + len = p - stackblock(); + return (growstrstackblock(len, min)); +} + + +char * +stputbin(const char *data, size_t len, char *p) +{ + CHECKSTRSPACE(len, p); + memcpy(p, data, len); + return (p + len); +} + +char * +stputs(const char *data, char *p) +{ + return (stputbin(data, strlen(data), p)); +} |