http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55173
Bug #: 55173
Summary: GCC gives wrong location, and ignores -isystem, when
warning about default arguments
Classification: Unclassified
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: mw_tr...@users.sourceforge.net
This came up originally related to bug 52718, but according to Paolo there, is
not actually related at all...
Consider the following header:
#pragma GCC system_header // or include via -isystem
class Foo
{
Foo(void* = 0);
};
class Bar
{
Bar(Foo = 0, void* = 0)
};
The following instantiation:
Bar bar;
...trips -Wzero-as-null-pointer-constant (also, the warning is reported in the
source file, not the header).
This appears to only happen when a default parameter implicitly invokes a
constructor, where the warning occurs in the constructor invocation. IOW, this:
Bar bar(nullptr);
...does not trigger a warning, as 'Foo(nullptr)' is okay.
Besides the less-helpful-than-desired diagnostic, this behavior is unfortunate,
as it prevents promoting warnings to errors in the face of such constructs, or
else forcing programmers to avoid use of default parameters.
