Mainline's C++ frontend warns about the following code snippet:
======================
int i=-1;
unsigned int j= ~0;
======================
warn.cc:2: warning: converting of negative value '-0x000000001' to
'unsigned int'
The strange thing is that the warning disappears if I comment out the
unrelated first line or change the value for "i" to "-2". Looks like
the cached constant determines the type of the new constant.
I'd expect "~0" to be signed and "~0u" to be unsigned, so I think the
warning is correct, but I'm not sure.
But in either case, the warning should not depend on some cached constant.
Btw, what about the constant 0xffffffff? Should a warning appear when
is's assigned to a signed or an unsigned int?
--
Summary: Warning depends on cached constant
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: reichelt at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19457
