1c62477cfSbostic /*- 2c62477cfSbostic * Copyright (c) 1991 The Regents of the University of California. 3c62477cfSbostic * All rights reserved. 4c62477cfSbostic * 5c62477cfSbostic * This code is derived from software contributed to Berkeley by 6c62477cfSbostic * Kenneth Almquist. 7c62477cfSbostic * 8c62477cfSbostic * %sccs.include.redist.c% 9c62477cfSbostic */ 10c62477cfSbostic 11c62477cfSbostic #ifndef lint 12*a65b7dceSmarc static char sccsid[] = "@(#)memalloc.c 5.2 (Berkeley) 03/13/91"; 13c62477cfSbostic #endif /* not lint */ 14c62477cfSbostic 15c62477cfSbostic #include "shell.h" 16c62477cfSbostic #include "output.h" 17c62477cfSbostic #include "memalloc.h" 18c62477cfSbostic #include "error.h" 19c62477cfSbostic #include "machdep.h" 20c62477cfSbostic #include "mystring.h" 21c62477cfSbostic 22c62477cfSbostic /* 23c62477cfSbostic * Like malloc, but returns an error when out of space. 24c62477cfSbostic */ 25c62477cfSbostic 26c62477cfSbostic pointer 27c62477cfSbostic ckmalloc(nbytes) { 28c62477cfSbostic register pointer p; 29c62477cfSbostic pointer malloc(); 30c62477cfSbostic 31c62477cfSbostic if ((p = malloc(nbytes)) == NULL) 32c62477cfSbostic error("Out of space"); 33c62477cfSbostic return p; 34c62477cfSbostic } 35c62477cfSbostic 36c62477cfSbostic 37c62477cfSbostic /* 38c62477cfSbostic * Same for realloc. 39c62477cfSbostic */ 40c62477cfSbostic 41c62477cfSbostic pointer 42c62477cfSbostic ckrealloc(p, nbytes) 43c62477cfSbostic register pointer p; 44c62477cfSbostic { 45c62477cfSbostic pointer realloc(); 46c62477cfSbostic 47c62477cfSbostic if ((p = realloc(p, nbytes)) == NULL) 48c62477cfSbostic error("Out of space"); 49c62477cfSbostic return p; 50c62477cfSbostic } 51c62477cfSbostic 52c62477cfSbostic 53c62477cfSbostic /* 54c62477cfSbostic * Make a copy of a string in safe storage. 55c62477cfSbostic */ 56c62477cfSbostic 57c62477cfSbostic char * 58c62477cfSbostic savestr(s) 59c62477cfSbostic char *s; 60c62477cfSbostic { 61c62477cfSbostic register char *p; 62c62477cfSbostic 63c62477cfSbostic p = ckmalloc(strlen(s) + 1); 64c62477cfSbostic scopy(s, p); 65c62477cfSbostic return p; 66c62477cfSbostic } 67c62477cfSbostic 68c62477cfSbostic 69c62477cfSbostic /* 70c62477cfSbostic * Parse trees for commands are allocated in lifo order, so we use a stack 71c62477cfSbostic * to make this more efficient, and also to avoid all sorts of exception 72c62477cfSbostic * handling code to handle interrupts in the middle of a parse. 73c62477cfSbostic * 74c62477cfSbostic * The size 504 was chosen because the Ultrix malloc handles that size 75c62477cfSbostic * well. 76c62477cfSbostic */ 77c62477cfSbostic 78c62477cfSbostic #define MINSIZE 504 /* minimum size of a block */ 79c62477cfSbostic 80c62477cfSbostic 81c62477cfSbostic struct stack_block { 82c62477cfSbostic struct stack_block *prev; 83c62477cfSbostic char space[MINSIZE]; 84c62477cfSbostic }; 85c62477cfSbostic 86c62477cfSbostic struct stack_block stackbase; 87c62477cfSbostic struct stack_block *stackp = &stackbase; 88c62477cfSbostic char *stacknxt = stackbase.space; 89c62477cfSbostic int stacknleft = MINSIZE; 90c62477cfSbostic int sstrnleft; 91c62477cfSbostic int herefd = -1; 92c62477cfSbostic 93c62477cfSbostic 94c62477cfSbostic 95c62477cfSbostic pointer 96c62477cfSbostic stalloc(nbytes) { 97c62477cfSbostic register char *p; 98c62477cfSbostic 99c62477cfSbostic nbytes = ALIGN(nbytes); 100c62477cfSbostic if (nbytes > stacknleft) { 101c62477cfSbostic int blocksize; 102c62477cfSbostic struct stack_block *sp; 103c62477cfSbostic 104c62477cfSbostic blocksize = nbytes; 105c62477cfSbostic if (blocksize < MINSIZE) 106c62477cfSbostic blocksize = MINSIZE; 107c62477cfSbostic INTOFF; 108c62477cfSbostic sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); 109c62477cfSbostic sp->prev = stackp; 110c62477cfSbostic stacknxt = sp->space; 111c62477cfSbostic stacknleft = blocksize; 112c62477cfSbostic stackp = sp; 113c62477cfSbostic INTON; 114c62477cfSbostic } 115c62477cfSbostic p = stacknxt; 116c62477cfSbostic stacknxt += nbytes; 117c62477cfSbostic stacknleft -= nbytes; 118c62477cfSbostic return p; 119c62477cfSbostic } 120c62477cfSbostic 121c62477cfSbostic 122c62477cfSbostic void 123c62477cfSbostic stunalloc(p) 124c62477cfSbostic pointer p; 125c62477cfSbostic { 126c62477cfSbostic if (p == NULL) { /*DEBUG */ 127c62477cfSbostic write(2, "stunalloc\n", 10); 128c62477cfSbostic abort(); 129c62477cfSbostic } 130c62477cfSbostic stacknleft += stacknxt - (char *)p; 131c62477cfSbostic stacknxt = p; 132c62477cfSbostic } 133c62477cfSbostic 134c62477cfSbostic 135c62477cfSbostic 136c62477cfSbostic void 137c62477cfSbostic setstackmark(mark) 138c62477cfSbostic struct stackmark *mark; 139c62477cfSbostic { 140c62477cfSbostic mark->stackp = stackp; 141c62477cfSbostic mark->stacknxt = stacknxt; 142c62477cfSbostic mark->stacknleft = stacknleft; 143c62477cfSbostic } 144c62477cfSbostic 145c62477cfSbostic 146c62477cfSbostic void 147c62477cfSbostic popstackmark(mark) 148c62477cfSbostic struct stackmark *mark; 149c62477cfSbostic { 150c62477cfSbostic struct stack_block *sp; 151c62477cfSbostic 152c62477cfSbostic INTOFF; 153c62477cfSbostic while (stackp != mark->stackp) { 154c62477cfSbostic sp = stackp; 155c62477cfSbostic stackp = sp->prev; 156c62477cfSbostic ckfree(sp); 157c62477cfSbostic } 158c62477cfSbostic stacknxt = mark->stacknxt; 159c62477cfSbostic stacknleft = mark->stacknleft; 160c62477cfSbostic INTON; 161c62477cfSbostic } 162c62477cfSbostic 163c62477cfSbostic 164c62477cfSbostic /* 165c62477cfSbostic * When the parser reads in a string, it wants to stick the string on the 166c62477cfSbostic * stack and only adjust the stack pointer when it knows how big the 167c62477cfSbostic * string is. Stackblock (defined in stack.h) returns a pointer to a block 168c62477cfSbostic * of space on top of the stack and stackblocklen returns the length of 169c62477cfSbostic * this block. Growstackblock will grow this space by at least one byte, 170c62477cfSbostic * possibly moving it (like realloc). Grabstackblock actually allocates the 171c62477cfSbostic * part of the block that has been used. 172c62477cfSbostic */ 173c62477cfSbostic 174c62477cfSbostic void 175c62477cfSbostic growstackblock() { 176c62477cfSbostic char *p; 177c62477cfSbostic int newlen = stacknleft * 2 + 100; 178c62477cfSbostic char *oldspace = stacknxt; 179c62477cfSbostic int oldlen = stacknleft; 180c62477cfSbostic struct stack_block *sp; 181c62477cfSbostic 182*a65b7dceSmarc if (stacknxt == stackp->space && stackp != &stackbase) { 183c62477cfSbostic INTOFF; 184c62477cfSbostic sp = stackp; 185c62477cfSbostic stackp = sp->prev; 186c62477cfSbostic sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); 187c62477cfSbostic sp->prev = stackp; 188c62477cfSbostic stackp = sp; 189c62477cfSbostic stacknxt = sp->space; 190c62477cfSbostic stacknleft = newlen; 191c62477cfSbostic INTON; 192c62477cfSbostic } else { 193c62477cfSbostic p = stalloc(newlen); 194c62477cfSbostic bcopy(oldspace, p, oldlen); 195c62477cfSbostic stacknxt = p; /* free the space */ 196c62477cfSbostic stacknleft += newlen; /* we just allocated */ 197c62477cfSbostic } 198c62477cfSbostic } 199c62477cfSbostic 200c62477cfSbostic 201c62477cfSbostic 202c62477cfSbostic void 203c62477cfSbostic grabstackblock(len) { 204c62477cfSbostic len = ALIGN(len); 205c62477cfSbostic stacknxt += len; 206c62477cfSbostic stacknleft -= len; 207c62477cfSbostic } 208c62477cfSbostic 209c62477cfSbostic 210c62477cfSbostic 211c62477cfSbostic /* 212c62477cfSbostic * The following routines are somewhat easier to use that the above. 213c62477cfSbostic * The user declares a variable of type STACKSTR, which may be declared 214c62477cfSbostic * to be a register. The macro STARTSTACKSTR initializes things. Then 215c62477cfSbostic * the user uses the macro STPUTC to add characters to the string. In 216c62477cfSbostic * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is 217c62477cfSbostic * grown as necessary. When the user is done, she can just leave the 218c62477cfSbostic * string there and refer to it using stackblock(). Or she can allocate 219c62477cfSbostic * the space for it using grabstackstr(). If it is necessary to allow 220c62477cfSbostic * someone else to use the stack temporarily and then continue to grow 221c62477cfSbostic * the string, the user should use grabstack to allocate the space, and 222c62477cfSbostic * then call ungrabstr(p) to return to the previous mode of operation. 223c62477cfSbostic * 224c62477cfSbostic * USTPUTC is like STPUTC except that it doesn't check for overflow. 225c62477cfSbostic * CHECKSTACKSPACE can be called before USTPUTC to ensure that there 226c62477cfSbostic * is space for at least one character. 227c62477cfSbostic */ 228c62477cfSbostic 229c62477cfSbostic 230c62477cfSbostic char * 231c62477cfSbostic growstackstr() { 232c62477cfSbostic int len = stackblocksize(); 233*a65b7dceSmarc if (herefd >= 0 && len >= 1024) { 234c62477cfSbostic xwrite(herefd, stackblock(), len); 235c62477cfSbostic sstrnleft = len - 1; 236c62477cfSbostic return stackblock(); 237c62477cfSbostic } 238c62477cfSbostic growstackblock(); 239c62477cfSbostic sstrnleft = stackblocksize() - len - 1; 240c62477cfSbostic return stackblock() + len; 241c62477cfSbostic } 242c62477cfSbostic 243c62477cfSbostic 244c62477cfSbostic /* 245c62477cfSbostic * Called from CHECKSTRSPACE. 246c62477cfSbostic */ 247c62477cfSbostic 248c62477cfSbostic char * 249c62477cfSbostic makestrspace() { 250c62477cfSbostic int len = stackblocksize() - sstrnleft; 251c62477cfSbostic growstackblock(); 252c62477cfSbostic sstrnleft = stackblocksize() - len; 253c62477cfSbostic return stackblock() + len; 254c62477cfSbostic } 255c62477cfSbostic 256c62477cfSbostic 257c62477cfSbostic 258c62477cfSbostic void 259c62477cfSbostic ungrabstackstr(s, p) 260c62477cfSbostic char *s; 261c62477cfSbostic char *p; 262c62477cfSbostic { 263c62477cfSbostic stacknleft += stacknxt - s; 264c62477cfSbostic stacknxt = s; 265c62477cfSbostic sstrnleft = stacknleft - (p - s); 266c62477cfSbostic } 267