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std::malloc has implementation defined behavior for size=0. Handle this correctly.

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This commit is contained in:
Sebastian Messmer 2017-10-27 03:58:44 +01:00
parent 8eac0f055f
commit 27fba3252e
1 changed files with 12 additions and 11 deletions
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23
src/cpp-utils/data/Data.h
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@ -55,6 +55,7 @@ private:
static std::streampos _getStreamSize(std::istream &stream); static std::streampos _getStreamSize(std::istream &stream);
void _readFromStream(std::istream &stream); void _readFromStream(std::istream &stream);
static void* _alloc(size_t size);
DISALLOW_COPY_AND_ASSIGN(Data); DISALLOW_COPY_AND_ASSIGN(Data);
}; };
@ -62,14 +63,20 @@ private:
bool operator==(const Data &lhs, const Data &rhs); bool operator==(const Data &lhs, const Data &rhs);
bool operator!=(const Data &lhs, const Data &rhs); bool operator!=(const Data &lhs, const Data &rhs);
inline void* Data::_alloc(size_t size) {
// std::malloc has implementation defined behavior for size=0.
// Let's define the behavior.
return std::malloc((size == 0)?1:size);
}
// --------------------------- // ---------------------------
// Inline function definitions // Inline function definitions
// --------------------------- // ---------------------------
inline Data::Data(size_t size) inline Data::Data(size_t size)
: _size(size), _data((size == 0)?nullptr:std::malloc(size)) { : _size(size), _data(_alloc(size)) {
if (_size != 0 && nullptr == _data) { if (nullptr == _data) {
throw std::bad_alloc(); throw std::bad_alloc();
} }
} }
@ -98,18 +105,14 @@ inline Data::~Data() {
inline Data Data::copy() const { inline Data Data::copy() const {
Data copy(_size); Data copy(_size);
if (_size != 0) { std::memcpy(copy._data, _data, _size);
std::memcpy(copy._data, _data, _size);
}
return copy; return copy;
} }
inline Data Data::copyAndRemovePrefix(size_t prefixSize) const { inline Data Data::copyAndRemovePrefix(size_t prefixSize) const {
ASSERT(prefixSize <= _size, "Can't remove more than there is"); ASSERT(prefixSize <= _size, "Can't remove more than there is");
Data copy(_size - prefixSize); Data copy(_size - prefixSize);
if (_size != 0) { // If _size == 0, then _data == nullptr, so better don't call memcpy. std::memcpy(copy.data(), dataOffset(prefixSize), copy.size());
std::memcpy(copy.data(), dataOffset(prefixSize), copy.size());
}
return copy; return copy;
} }
@ -134,9 +137,7 @@ inline size_t Data::size() const {
} }
inline Data &Data::FillWithZeroes() & { inline Data &Data::FillWithZeroes() & {
if (_size != 0) { std::memset(_data, 0, _size);
std::memset(_data, 0, _size);
}
return *this; return *this;
} }