| Issue |
125257
|
| Summary |
[clang] C++ constructor arguments should support [[clang::lifetimebound]]
|
| Labels |
clang
|
| Assignees |
|
| Reporter |
ddkilzer
|
The `[[clang::lifetimebound]]` attribute should be supported on C++ constructor arguments when the class takes a reference to an object whose lifetime must extend past an instance of the class.
In other words, the `this` object returned from the constructor should have its lifetime bound to one or more of its constructor arguments.
This should also apply to `struct` constructors in C++. (Changing `class buffer_view` to `struct buffer_view` below demonstrates this in Godbolt.)
https://godbolt.org/z/x665eWPqd
```
#include <iostream>
#include <span>
#include <string>
class buffer_view {
public:
buffer_view(const std::basic_string<char>& s [[clang::lifetimebound]]);
std::basic_string<char> s();
private:
std::span<const char> m_view;
};
buffer_view::buffer_view(const std::basic_string<char>& s)
: m_view({ s.data(), s.size() })
{
}
std::basic_string<char> buffer_view::s()
{
return { m_view.data(), m_view.size() };
}
int main(int argc, char** argv)
{
buffer_view bv { std::string("foo") }; // expected warning
std::cout << bv.s(); // use-after-free crash with address sanitizer
return 0;
}
```
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