Re: Why this code generates exception?

From:

Paavo Helde <myfirstname@osa.pri.ee>

Newsgroups:

comp.lang.c++

Date:

Fri, 26 Nov 2010 15:25:30 -0600

Message-ID:

<Xns9E3CEE4B04022myfirstnameosapriee@216.196.109.131>

fl <rxjwg98@gmail.com> wrote in
news:61cd1a24-39bf-4ed2-9373-02148c885e16@v17g2000prc.googlegroups.com:

Hi,
I am using SystemC, a kind of C++ library to do some simulation. I
find the example code, see below:
..............
SC_MODULE(isq)
{
        sc_in<bool> RSTN;
        sc_in_clk CLK;

        sc_out<bool> DIN_rdy;
        sc_in<bool> DIN_vld;
        sc_in<sc_uint<18> > DIN_value;
        sc_in<bool> DOUT_rdy;
        sc_out<bool> DOUT_vld;
        sc_out<sc_uint<10> > DOUT_value;

     void thread();
     sc_uint<10> isqrt5(sc_uint<18>);

     SC_CTOR(isq){
          SC_CTHREAD(thread, CLK.pos());
          reset_signal_is(RSTN,false);
     }
};

.................
     isq *isqp;

     isqp = new isq("isq0");
     (*isqp)(reset, clk,
          in_rdy, in_vld, it,
          out_rdy, out_vld, is);

..............................

This code segment generates the following warning in "Microsoft Visual
C Express 2008".

..............
'isq_VS0.exe': Loaded 'C:\systemcfiles\SystemCsln0\Debug\isq_VS0.exe',
Symbols loaded.
'isq_VS0.exe': Loaded 'C:\WINDOWS\system32\ntdll.dll'
'isq_VS0.exe': Loaded 'C:\WINDOWS\system32\kernel32.dll'
First-chance exception at 0x7c812afb in isq_VS0.exe: Microsoft C++
exception: sc_core::sc_user at memory location 0x0086f947..
The program '[4224] isq_VS0.exe: Native' has exited with code 0 (0x0).

So, which line from the above do you call a "warning"?

The output shows that there has appeared an exception. If this bothers
you, catch the exception and study it in the code; alternatively, you can
instruct the visual studio debugger to stop when the exception appears so
you can study it _in situ_.

Some exceptions are harmless and are catched and handled some layers
higher inside the library. I have no idea if this applies in this case.
The fact that the program exited successfully hints that the exception
was catched and handled somehow.

hth
Paavo