Sorry, I should clarify that. Destructors for stack objects in C
functions aren't called when an exception is thrown. Testcase...
C:\>(type t.cpp) && (cl /nologo /EHsc t.cpp)
struct Object
{
static int counter;
Object() {
Object::counter += 1;
}
~Object() {
Object::counter -= 1;
}
};
/* static */
int Object::counter = 0;
extern "C" {
int extern_c_function (int x, int y, int (*fun)(int, int))
{
Object obj;
if (fun)
return fun (x, y);
return 0;
}
int div_throw (int x, int y)
{
Object obj;
if (0 == y)
throw y;
return x / y;
}
} // extern "C"
int main (int argc, char *argv[])
{
const int x = argc < 2 ? 0 : int (*argv [1]) - '0';
const int y = argc < 3 ? 0 : int (*argv [2]) - '0';
try {
extern_c_function (x, y, div_throw);
}
catch (int res) {
// nothing
}
return Object::counter != 0;
}
t.cpp
t.cpp(32) : warning C4297: 'div_throw' : function assumed not to throw
an exception but does
The function is extern "C" and /EHc was specified
C:\>t 1 1
C:\>if errorlevel 1 (echo failure) else (echo success!)
success!
C:\>t 1 0
C:\>if errorlevel 1 (echo failure!) else (echo success!)
failure!
>-----Original Message-----
>From: Travis Vitek [mailto:[EMAIL PROTECTED]
>Sent: Tuesday, August 14, 2007 5:18 PM
>To: stdcxx-dev@incubator.apache.org
>Subject: RE: svn commit: r565959 -
>/incubator/stdcxx/trunk/etc/config/src/EXTERN_C_EXCEPTIONS.cpp
>
>
>Martin,
>
>I'm not sure if you're aware, but I don't believe that the destructors
>for stack objects inside the C functions will be called. I know that
>this is the case for MSVC7/8. This isn't an issue for your
>testcase, but
>it may be an issue for the functions invoked by __rw_once.
>
>I think this is by design, but I found it a little weird that the ascii
>value of the first character of each parameter is passed to
>div_throw/div_nothrow. I had the urge to add modify the argument
>processing lines to something more like this so that I could pass
>arguments and get the expected results.
>
> const int x = argc < 2 ? 0 : int (*argv [1]) - '0';
> const int y = argc < 3 ? 0 : int (*argv [2]) - '0';
>
>Travis
>
>>
