From e77337588e75adc6e6b8477a8dbe9d1ea8f25c8c Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Wed, 15 Apr 2020 14:21:22 -0400
Subject: file_util: Early-exit in WriteArray and ReadArray if specified
lengths are zero
It's undefined behavior to pass a null pointer to std::fread and
std::fwrite, even if the length passed in is zero, so we must perform
the precondition checking ourselves.
A common case where this can occur is when passing in the data of an
empty std::vector and size, as an empty vector will typically have a
null internal buffer.
While we're at it, we can move the implementation out of line and add
debug checks against passing in nullptr to std::fread and std::fwrite.
---
src/common/file_util.cpp | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
(limited to 'src/common/file_util.cpp')
diff --git a/src/common/file_util.cpp b/src/common/file_util.cpp
index 35eee0096c..7f613891b3 100644
--- a/src/common/file_util.cpp
+++ b/src/common/file_util.cpp
@@ -967,6 +967,34 @@ bool IOFile::Flush() {
return IsOpen() && 0 == std::fflush(m_file);
}
+std::size_t IOFile::ReadImpl(void* data, std::size_t length, std::size_t data_size) const {
+ if (!IsOpen()) {
+ return std::numeric_limits<std::size_t>::max();
+ }
+
+ if (length == 0) {
+ return 0;
+ }
+
+ DEBUG_ASSERT(data != nullptr);
+
+ return std::fread(data, data_size, length, m_file);
+}
+
+std::size_t IOFile::WriteImpl(const void* data, std::size_t length, std::size_t data_size) {
+ if (!IsOpen()) {
+ return std::numeric_limits<std::size_t>::max();
+ }
+
+ if (length == 0) {
+ return 0;
+ }
+
+ DEBUG_ASSERT(data != nullptr);
+
+ return std::fwrite(data, data_size, length, m_file);
+}
+
bool IOFile::Resize(u64 size) {
return IsOpen() && 0 ==
#ifdef _WIN32
--
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