1/*********************************************************************** 2* * 3* This software is part of the ast package * 4* Copyright (c) 1985-2011 AT&T Intellectual Property * 5* and is licensed under the * 6* Eclipse Public License, Version 1.0 * 7* by AT&T Intellectual Property * 8* * 9* A copy of the License is available at * 10* http://www.eclipse.org/org/documents/epl-v10.html * 11* (with md5 checksum b35adb5213ca9657e911e9befb180842) * 12* * 13* Information and Software Systems Research * 14* AT&T Research * 15* Florham Park NJ * 16* * 17* Glenn Fowler <gsf@research.att.com> * 18* David Korn <dgk@research.att.com> * 19* Phong Vo <kpv@research.att.com> * 20* * 21***********************************************************************/ 22#pragma prototyped 23/* 24 * Glenn Fowler 25 * AT&T Bell Laboratories 26 * 27 * hash table library 28 */ 29 30#include "hashlib.h" 31 32/* 33 * push/pop/query hash table scope 34 * 35 * bot==0 pop top scope 36 * bot==top query 37 * bot!=0 push top on bot 38 * 39 * scope table pointer returned 40 */ 41 42Hash_table_t* 43hashview(Hash_table_t* top, Hash_table_t* bot) 44{ 45 register Hash_bucket_t* b; 46 register Hash_bucket_t* p; 47 register Hash_bucket_t** sp; 48 register Hash_bucket_t** sx; 49 50 if (!top || top->frozen) 51 bot = 0; 52 else if (top == bot) 53 bot = top->scope; 54 else if (bot) 55 { 56 if (top->scope) 57 bot = 0; 58 else 59 { 60 sx = &top->table[top->size]; 61 sp = &top->table[0]; 62 while (sp < sx) 63 for (b = *sp++; b; b = b->next) 64 if (p = (Hash_bucket_t*)hashlook(bot, b->name, HASH_LOOKUP, NiL)) 65 { 66 b->name = (p->hash & HASH_HIDES) ? p->name : (char*)b; 67 b->hash |= HASH_HIDES; 68 } 69 top->scope = bot; 70 bot->frozen++; 71 } 72 } 73 else if (bot = top->scope) 74 { 75 sx = &top->table[top->size]; 76 sp = &top->table[0]; 77 while (sp < sx) 78 for (b = *sp++; b; b = b->next) 79 if (b->hash & HASH_HIDES) 80 { 81 b->hash &= ~HASH_HIDES; 82 b->name = ((Hash_bucket_t*)b->name)->name; 83 } 84 top->scope = 0; 85 bot->frozen--; 86 } 87 return(bot); 88} 89