1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 * vim: set ts=8 sts=2 et sw=2 tw=80:
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "util/CompleteFile.h"
8
9 #include <cstring> // std::strcmp
10 #include <stdio.h> // FILE, fileno, fopen, getc, getc_unlocked, _getc_nolock
11 #include <sys/stat.h> // stat, fstat
12
13 #ifdef __wasi__
14 # include "js/Vector.h"
15 #endif // __wasi__
16
17 #include "jsapi.h" // JS_ReportErrorNumberLatin1
18
19 #include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_CANT_OPEN
20
ReadCompleteFile(JSContext * cx,FILE * fp,FileContents & buffer)21 bool js::ReadCompleteFile(JSContext* cx, FILE* fp, FileContents& buffer) {
22 /* Get the complete length of the file, if possible. */
23 struct stat st;
24 int ok = fstat(fileno(fp), &st);
25 if (ok != 0) {
26 // Use the Latin1 variant here (and below), because the encoding of
27 // strerror() is platform-dependent.
28 JS_ReportErrorLatin1(cx, "error reading file: %s", strerror(errno));
29 errno = 0;
30 return false;
31 }
32 if ((st.st_mode & S_IFDIR) != 0) {
33 JS_ReportErrorLatin1(cx, "error reading file: %s", strerror(EISDIR));
34 return false;
35 }
36
37 if (st.st_size > 0) {
38 if (!buffer.reserve(st.st_size)) {
39 return false;
40 }
41 }
42
43 /* Use the fastest available getc. */
44 auto fast_getc =
45 #if defined(HAVE_GETC_UNLOCKED)
46 getc_unlocked
47 #elif defined(HAVE__GETC_NOLOCK)
48 _getc_nolock
49 #else
50 getc
51 #endif
52 ;
53
54 // Read in the whole file. Note that we can't assume the data's length
55 // is actually st.st_size, because 1) some files lie about their size
56 // (/dev/zero and /dev/random), and 2) reading files in text mode on
57 // Windows collapses "\r\n" pairs to single \n characters.
58 for (;;) {
59 int c = fast_getc(fp);
60 if (c == EOF) {
61 break;
62 }
63 if (!buffer.append(c)) {
64 return false;
65 }
66 }
67
68 if (ferror(fp)) {
69 // getc failed
70 JS_ReportErrorLatin1(cx, "error reading file: %s", strerror(errno));
71 errno = 0;
72 return false;
73 }
74
75 return true;
76 }
77
78 #ifdef __wasi__
NormalizeWASIPath(const char * filename,js::Vector<char> * normalized,JSContext * cx)79 static bool NormalizeWASIPath(const char* filename,
80 js::Vector<char>* normalized, JSContext* cx) {
81 // On WASI, we need to collapse ".." path components for the capabilities
82 // that we pass to our unit tests to be reasonable; otherwise we need to
83 // grant "tests/script1.js/../lib.js" and "tests/script2.js/../lib.js"
84 // separately (because the check appears to be a prefix only).
85 for (const char* cur = filename; *cur; ++cur) {
86 if (std::strncmp(cur, "/../", 4) == 0) {
87 do {
88 if (normalized->empty()) {
89 JS_ReportErrorASCII(cx, "Path processing error");
90 return false;
91 }
92 } while (normalized->popCopy() != '/');
93 cur += 2;
94 continue;
95 }
96 if (!normalized->append(*cur)) {
97 return false;
98 }
99 }
100 if (!normalized->append('\0')) {
101 return false;
102 }
103 return true;
104 }
105 #endif
106
107 /*
108 * Open a source file for reading. Supports "-" and nullptr to mean stdin. The
109 * return value must be fclosed unless it is stdin.
110 */
open(JSContext * cx,const char * filename)111 bool js::AutoFile::open(JSContext* cx, const char* filename) {
112 if (!filename || std::strcmp(filename, "-") == 0) {
113 fp_ = stdin;
114 } else {
115 #ifdef __wasi__
116 js::Vector<char> normalized(cx);
117 if (!NormalizeWASIPath(filename, &normalized, cx)) {
118 return false;
119 }
120 fp_ = fopen(normalized.begin(), "r");
121 #else
122 fp_ = fopen(filename, "r");
123 #endif
124 if (!fp_) {
125 /*
126 * Use Latin1 variant here because the encoding of filename is
127 * platform dependent.
128 */
129 JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_CANT_OPEN,
130 filename, "No such file or directory");
131 return false;
132 }
133 }
134 return true;
135 }
136