diff options
| author | Lioncash <mathew1800@gmail.com> | 2020-04-15 14:21:22 -0400 |
|---|---|---|
| committer | Lioncash <mathew1800@gmail.com> | 2020-04-15 14:43:37 -0400 |
| commit | e77337588e75adc6e6b8477a8dbe9d1ea8f25c8c (patch) | |
| tree | 0b6d9732e5276abf734e64dcd708a18da1e931a4 | |
| parent | 64b5985f0a034fb2b1988d960b009985f9929922 (diff) | |
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.
| -rw-r--r-- | src/common/file_util.cpp | 28 | ||||
| -rw-r--r-- | src/common/file_util.h | 14 |
2 files changed, 33 insertions, 9 deletions
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 diff --git a/src/common/file_util.h b/src/common/file_util.h index cde7ddf2d1..f7a0c33fae 100644 --- a/src/common/file_util.h +++ b/src/common/file_util.h @@ -222,22 +222,15 @@ public: static_assert(std::is_trivially_copyable_v<T>, "Given array does not consist of trivially copyable objects"); - if (!IsOpen()) { - return std::numeric_limits<std::size_t>::max(); - } - - return std::fread(data, sizeof(T), length, m_file); + return ReadImpl(data, length, sizeof(T)); } template <typename T> std::size_t WriteArray(const T* data, std::size_t length) { static_assert(std::is_trivially_copyable_v<T>, "Given array does not consist of trivially copyable objects"); - if (!IsOpen()) { - return std::numeric_limits<std::size_t>::max(); - } - return std::fwrite(data, sizeof(T), length, m_file); + return WriteImpl(data, length, sizeof(T)); } template <typename T> @@ -278,6 +271,9 @@ public: } private: + std::size_t ReadImpl(void* data, std::size_t length, std::size_t data_size) const; + std::size_t WriteImpl(const void* data, std::size_t length, std::size_t data_size); + std::FILE* m_file = nullptr; }; |