[Bug c++/47634] New: Incorrect checking of attribute format printf on constructor of derived class with virtual base

[dan at randomdan dot homeip.net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47634

           Summary: Incorrect checking of attribute format printf on
                    constructor of derived class with virtual base
           Product: gcc
           Version: 4.4.5
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: d...@randomdan.homeip.net


Given the below code, gcc produces the following warnings:

exception.cpp: In function 'int main(int, char**)':
exception.cpp:28: warning: format not a string literal and no format arguments

Changing the __attribute__ on VDerived's constructor to be the same as Derived
produces the following error:
exception.cpp:9: error: format string argument not a string type

Compiled simply with:
g++ exception.cpp

class Base {
    public:
        Base() {
        }
};

class VDerived : public virtual Base {
    public:
        VDerived(int x, const char * f, ...) __attribute__((format(printf, 5,
6)));
};

class Derived : public Base {
    public:
        Derived(int x, const char * f, ...) __attribute__((format(printf, 3,
4)));
};

VDerived::VDerived(int x, const char * f, ...)
{
}

Derived::Derived(int x, const char * f, ...)
{
}

int
main(int, char **)
{
    throw VDerived(1, "%s %d", "foo", 1);
    throw Derived(1, "%s %d", "bar", 1);
}