| File: | jdk/src/java.base/unix/native/libjava/path_util.c |
| Warning: | line 134, column 13 Assigned value is garbage or undefined |
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| 1 | /* | |||
| 2 | * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved. | |||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |||
| 4 | * | |||
| 5 | * This code is free software; you can redistribute it and/or modify it | |||
| 6 | * under the terms of the GNU General Public License version 2 only, as | |||
| 7 | * published by the Free Software Foundation. Oracle designates this | |||
| 8 | * particular file as subject to the "Classpath" exception as provided | |||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | |||
| 10 | * | |||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | |||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | |||
| 15 | * accompanied this code). | |||
| 16 | * | |||
| 17 | * You should have received a copy of the GNU General Public License version | |||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | |||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |||
| 20 | * | |||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |||
| 22 | * or visit www.oracle.com if you need additional information or have any | |||
| 23 | * questions. | |||
| 24 | */ | |||
| 25 | ||||
| 26 | #include <stdlib.h> | |||
| 27 | #include <string.h> | |||
| 28 | #if !defined(_ALLBSD_SOURCE) | |||
| 29 | #include <alloca.h> | |||
| 30 | #endif | |||
| 31 | ||||
| 32 | #include "path_util.h" | |||
| 33 | ||||
| 34 | /* Check the given name sequence to see if it can be further collapsed. | |||
| 35 | Return zero if not, otherwise return the number of names in the sequence. */ | |||
| 36 | ||||
| 37 | static int | |||
| 38 | collapsible(char *names) | |||
| 39 | { | |||
| 40 | char *p = names; | |||
| 41 | int dots = 0, n = 0; | |||
| 42 | ||||
| 43 | while (*p) { | |||
| 44 | if ((p[0] == '.') && ((p[1] == '\0') | |||
| 45 | || (p[1] == '/') | |||
| 46 | || ((p[1] == '.') && ((p[2] == '\0') | |||
| 47 | || (p[2] == '/'))))) { | |||
| 48 | dots = 1; | |||
| 49 | } | |||
| 50 | n++; | |||
| 51 | while (*p) { | |||
| 52 | if (*p == '/') { | |||
| 53 | p++; | |||
| 54 | break; | |||
| 55 | } | |||
| 56 | p++; | |||
| 57 | } | |||
| 58 | } | |||
| 59 | return (dots ? n : 0); | |||
| 60 | } | |||
| 61 | ||||
| 62 | ||||
| 63 | /* Split the names in the given name sequence, | |||
| 64 | replacing slashes with nulls and filling in the given index array */ | |||
| 65 | ||||
| 66 | static void | |||
| 67 | splitNames(char *names, char **ix) | |||
| 68 | { | |||
| 69 | char *p = names; | |||
| 70 | int i = 0; | |||
| 71 | ||||
| 72 | while (*p) { | |||
| 73 | ix[i++] = p++; | |||
| 74 | while (*p) { | |||
| 75 | if (*p == '/') { | |||
| 76 | *p++ = '\0'; | |||
| 77 | break; | |||
| 78 | } | |||
| 79 | p++; | |||
| 80 | } | |||
| 81 | } | |||
| 82 | } | |||
| 83 | ||||
| 84 | ||||
| 85 | /* Join the names in the given name sequence, ignoring names whose index | |||
| 86 | entries have been cleared and replacing nulls with slashes as needed */ | |||
| 87 | ||||
| 88 | static void | |||
| 89 | joinNames(char *names, int nc, char **ix) | |||
| 90 | { | |||
| 91 | int i; | |||
| 92 | char *p; | |||
| 93 | ||||
| 94 | for (i = 0, p = names; i < nc; i++) { | |||
| 95 | if (!ix[i]) continue; | |||
| 96 | if (i > 0) { | |||
| 97 | p[-1] = '/'; | |||
| 98 | } | |||
| 99 | if (p == ix[i]) { | |||
| 100 | p += strlen(p) + 1; | |||
| 101 | } else { | |||
| 102 | char *q = ix[i]; | |||
| 103 | while ((*p++ = *q++)); | |||
| 104 | } | |||
| 105 | } | |||
| 106 | *p = '\0'; | |||
| 107 | } | |||
| 108 | ||||
| 109 | /* Collapse "." and ".." names in the given path wherever possible. | |||
| 110 | A "." name may always be eliminated; a ".." name may be eliminated if it | |||
| 111 | follows a name that is neither "." nor "..". This is a syntactic operation | |||
| 112 | that performs no filesystem queries, so it should only be used to cleanup | |||
| 113 | after invoking the realpath() procedure. */ | |||
| 114 | ||||
| 115 | void | |||
| 116 | collapse(char *path) | |||
| 117 | { | |||
| 118 | char *names = (path[0] == '/') ? path + 1 : path; /* Preserve first '/' */ | |||
| ||||
| 119 | int nc; | |||
| 120 | char **ix; | |||
| 121 | int i, j; | |||
| 122 | char *p, *q; | |||
| 123 | ||||
| 124 | nc = collapsible(names); | |||
| 125 | if (nc < 2) return; /* Nothing to do */ | |||
| 126 | ix = (char **)alloca(nc * sizeof(char *))__builtin_alloca (nc * sizeof(char *)); | |||
| 127 | splitNames(names, ix); | |||
| 128 | ||||
| 129 | for (i = 0; i
| |||
| 130 | int dots = 0; | |||
| 131 | ||||
| 132 | /* Find next occurrence of "." or ".." */ | |||
| 133 | do { | |||
| 134 | char *p = ix[i]; | |||
| ||||
| 135 | if (p[0] == '.') { | |||
| 136 | if (p[1] == '\0') { | |||
| 137 | dots = 1; | |||
| 138 | break; | |||
| 139 | } | |||
| 140 | if ((p[1] == '.') && (p[2] == '\0')) { | |||
| 141 | dots = 2; | |||
| 142 | break; | |||
| 143 | } | |||
| 144 | } | |||
| 145 | i++; | |||
| 146 | } while (i < nc); | |||
| 147 | if (i >= nc) break; | |||
| 148 | ||||
| 149 | /* At this point i is the index of either a "." or a "..", so take the | |||
| 150 | appropriate action and then continue the outer loop */ | |||
| 151 | if (dots == 1) { | |||
| 152 | /* Remove this instance of "." */ | |||
| 153 | ix[i] = 0; | |||
| 154 | } | |||
| 155 | else { | |||
| 156 | /* If there is a preceding name, remove both that name and this | |||
| 157 | instance of ".."; otherwise, leave the ".." as is */ | |||
| 158 | for (j = i - 1; j >= 0; j--) { | |||
| 159 | if (ix[j]) break; | |||
| 160 | } | |||
| 161 | if (j < 0) continue; | |||
| 162 | ix[j] = 0; | |||
| 163 | ix[i] = 0; | |||
| 164 | } | |||
| 165 | /* i will be incremented at the top of the loop */ | |||
| 166 | } | |||
| 167 | ||||
| 168 | joinNames(names, nc, ix); | |||
| 169 | } |