https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116697
Bug ID: 116697
Summary: Bogus -Wuninitialized warning when no access to
uninitialized data is done
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: andysem at mail dot ru
Target Milestone: ---
Consider this example:
struct array
{
char m_buf[10];
typedef char* iterator;
iterator begin() { return m_buf; }
};
struct buffer
{
array m_buffer;
array::iterator m_it;
buffer() : m_it(m_buffer.begin()) {}
};
Compiling this with `g++ -Wall` produces this warning:
<source>: In constructor 'buffer::buffer()':
<source>:15:21: warning: member 'buffer::m_buffer' is used uninitialized
[-Wuninitialized]
15 | buffer() : m_it(m_buffer.begin()) {}
| ^~~~~~~~
https://godbolt.org/z/Mexvadbss
In this case, although the default constructor of `array` is trivial, it would
have been called at the point of `buffer::m_it` construction. And even though
the contents of `array::m_buf` are undefined, the code does not access it
either. I think, the warning is incorrect in this case as no uninitialized data
is accessed here.
