/*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * Copyright (c) 1997-2005 * Herbert Xu . 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 #include #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. */ static void growstackblock(size_t min) { size_t newlen; newlen = stacknleft * 2; if (newlen < stacknleft) sh_error("Out of space"); min = SHELL_ALIGN(min | 128); if (newlen < min) newlen += min; 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(0); return stackblock() + len; } char *growstackto(size_t len) { if (stackblocksize() < len) growstackblock(len); return stackblock(); } /* * Called from CHECKSTRSPACE. */ char * makestrspace(size_t newlen, char *p) { size_t len = p - stacknxt; return growstackto(len + newlen) + 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); }