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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /mozglue/interposers/getline_interposer.cpp
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mozglue/interposers/getline_interposer.cpp')
-rw-r--r--mozglue/interposers/getline_interposer.cpp110
1 files changed, 110 insertions, 0 deletions
diff --git a/mozglue/interposers/getline_interposer.cpp b/mozglue/interposers/getline_interposer.cpp
new file mode 100644
index 0000000000..902b52b718
--- /dev/null
+++ b/mozglue/interposers/getline_interposer.cpp
@@ -0,0 +1,110 @@
+/* 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Interposing getline because of
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=914190
+ */
+
+#ifdef __ANDROID__
+
+# include <cstdlib>
+# include <cstdio>
+# include <cerrno>
+
+# include <limits>
+
+namespace {
+
+// RAII on file locking.
+class FileLocker {
+ FILE* stream;
+
+ public:
+ explicit FileLocker(FILE* stream) : stream(stream) { flockfile(stream); }
+ ~FileLocker() { funlockfile(stream); }
+};
+
+ssize_t internal_getdelim(char** __restrict lineptr, size_t* __restrict n,
+ int delim, FILE* __restrict stream) {
+ constexpr size_t n_default = 64;
+ constexpr size_t n_max =
+ std::numeric_limits<ssize_t>::max() < std::numeric_limits<size_t>::max()
+ ? (size_t)std::numeric_limits<ssize_t>::max() + 1
+ : std::numeric_limits<size_t>::max();
+ constexpr size_t n_limit = 2 * ((n_max - 1) / 3);
+
+ if (!lineptr || !n || !stream) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ // Lock the file so that we can us unlocked getc in the inner loop.
+ FileLocker fl(stream);
+
+ if (!*lineptr || *n == 0) {
+ *n = n_default;
+ if (auto* new_lineptr = reinterpret_cast<char*>(realloc(*lineptr, *n))) {
+ *lineptr = new_lineptr;
+ } else {
+ errno = ENOMEM;
+ return -1;
+ }
+ }
+
+ ssize_t result;
+ size_t cur_len = 0;
+
+ while (true) {
+ // Retrieve an extra char.
+ int i = getc_unlocked(stream);
+ if (i == EOF) {
+ result = -1;
+ break;
+ }
+
+ // Eventually grow the buffer.
+ if (cur_len + 1 >= *n) {
+ size_t needed = *n >= n_limit ? n_max : 3 * *n / 2 + 1;
+
+ if (cur_len + 1 >= needed) {
+ errno = EOVERFLOW;
+ return -1;
+ }
+
+ if (auto* new_lineptr = (char*)realloc(*lineptr, needed)) {
+ *lineptr = new_lineptr;
+ } else {
+ errno = ENOMEM;
+ return -1;
+ }
+ *n = needed;
+ }
+
+ (*lineptr)[cur_len] = i;
+ cur_len++;
+
+ if (i == delim) break;
+ }
+ (*lineptr)[cur_len] = '\0';
+ return cur_len ? cur_len : result;
+}
+
+} // namespace
+
+extern "C" {
+
+MFBT_API ssize_t getline(char** __restrict lineptr, size_t* __restrict n,
+ FILE* __restrict stream) {
+ return internal_getdelim(lineptr, n, '\n', stream);
+}
+
+MFBT_API ssize_t getdelim(char** __restrict lineptr, size_t* __restrict n,
+ int delim, FILE* __restrict stream) {
+ return internal_getdelim(lineptr, n, delim, stream);
+}
+
+} // extern "C"
+
+#endif