https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78973
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Summary|warning: ‘memcpy’: |[7.0 regression] warning:
|specified size between |‘memcpy’: specified size
|18446744071562067968 and |between
|18446744073709551615 |18446744071562067968 and
|exceeds maximum object size |18446744073709551615
|9223372036854775807 |exceeds maximum object size
|[-Wstringop-overflow=] |9223372036854775807
| |[-Wstringop-overflow=]
Severity|enhancement |normal
--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
Thanks. The range printed in the diagnostic corresponds to the range of the
signed variable passed to memcpy() after conversion to size_t. The (signed)
range is reported by the get_range_info() function as [-2147483648, -1]. The
converted variable's def_stmt looks like this:
_309 = (long unsigned int) len_137;
The range of the len_137 variable whose type is int is [-2147483648,
2147483647], or the full range of its type, so the unsigned range has to be
considered to be [0, SIZE_MAX]. I'm testing a patch to detect this and avoid
the false positive.
