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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "util/CompleteFile.h"
#include <cstring> // std::strcmp
#include <stdio.h> // FILE, fileno, fopen, getc, getc_unlocked, _getc_nolock
#include <sys/stat.h> // stat, fstat
#ifdef __wasi__
# include "js/Vector.h"
#endif // __wasi__
#include "js/CharacterEncoding.h" // EncodeUtf8ToWide, EncodeUtf8ToNarrow
#include "js/ErrorReport.h" // JS_ReportErrorNumberUTF8
#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_CANT_OPEN
bool js::ReadCompleteFile(JSContext* cx, FILE* fp, FileContents& buffer) {
/* Get the complete length of the file, if possible. */
struct stat st;
int ok = fstat(fileno(fp), &st);
if (ok != 0) {
// Use the Latin1 variant here (and below), because the encoding of
// strerror() is platform-dependent.
JS_ReportErrorLatin1(cx, "error reading file: %s", strerror(errno));
errno = 0;
return false;
}
if ((st.st_mode & S_IFDIR) != 0) {
JS_ReportErrorLatin1(cx, "error reading file: %s", strerror(EISDIR));
return false;
}
if (st.st_size > 0) {
if (!buffer.reserve(st.st_size)) {
return false;
}
}
/* Use the fastest available getc. */
auto fast_getc =
#if defined(HAVE_GETC_UNLOCKED)
getc_unlocked
#elif defined(HAVE__GETC_NOLOCK)
_getc_nolock
#else
getc
#endif
;
// Read in the whole file. Note that we can't assume the data's length
// is actually st.st_size, because 1) some files lie about their size
// (/dev/zero and /dev/random), and 2) reading files in text mode on
// Windows collapses "\r\n" pairs to single \n characters.
for (;;) {
int c = fast_getc(fp);
if (c == EOF) {
break;
}
if (!buffer.append(c)) {
return false;
}
}
if (ferror(fp)) {
// getc failed
JS_ReportErrorLatin1(cx, "error reading file: %s", strerror(errno));
errno = 0;
return false;
}
return true;
}
#ifdef __wasi__
static bool NormalizeWASIPath(const char* filename,
js::Vector<char>* normalized, JSContext* cx) {
// On WASI, we need to collapse ".." path components for the capabilities
// that we pass to our unit tests to be reasonable; otherwise we need to
// grant "tests/script1.js/../lib.js" and "tests/script2.js/../lib.js"
// separately (because the check appears to be a prefix only).
for (const char* cur = filename; *cur; ++cur) {
if (std::strncmp(cur, "/../", 4) == 0) {
do {
if (normalized->empty()) {
JS_ReportErrorASCII(cx, "Path processing error");
return false;
}
} while (normalized->popCopy() != '/');
cur += 2;
continue;
}
if (!normalized->append(*cur)) {
return false;
}
}
if (!normalized->append('\0')) {
return false;
}
return true;
}
#endif
static FILE* OpenFile(JSContext* cx, const char* filename) {
#ifdef XP_WIN
JS::UniqueWideChars wideFilename = JS::EncodeUtf8ToWide(cx, filename);
if (!wideFilename) {
return nullptr;
}
return _wfopen(wideFilename.get(), L"r");
#else
JS::UniqueChars narrowFilename = JS::EncodeUtf8ToNarrow(cx, filename);
if (!narrowFilename) {
return nullptr;
}
return fopen(narrowFilename.get(), "r");
#endif
}
/*
* Open a source file for reading. Supports "-" and nullptr to mean stdin. The
* return value must be fclosed unless it is stdin.
*/
bool js::AutoFile::open(JSContext* cx, const char* filename) {
if (!filename || std::strcmp(filename, "-") == 0) {
fp_ = stdin;
} else {
#ifdef __wasi__
js::Vector<char> normalized(cx);
if (!NormalizeWASIPath(filename, &normalized, cx)) {
return false;
}
fp_ = OpenFile(cx, normalized.begin());
#else
fp_ = OpenFile(cx, filename);
#endif
if (!fp_) {
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, JSMSG_CANT_OPEN,
filename, "No such file or directory");
return false;
}
}
return true;
}