c++filt causing flashing console windows

Tue Sep 9 09:48:00 GMT 2003

Ranjit Mathew writes:
 > Andrew Haley wrote:
 > > Ã˜yvind Harboe writes:
 > > > > > -Dgnu.gcj.runtime.NameFinder.demangle=false
 > > > > > -Dgnu.gcj.runtime.NameFinder.use_addr2line=false
 > > > >
 > > > >Surely the bug is not here. exec'ing c++filt and addr2line 
 > > > >should not cause anything to flash, and that is the bug.
 > > > 
 > > > Flashing isn't a very accurate technical term, I guess. :-)
 > > > 
 > > > When a GCJ application compiled with w/-mwindows
 > > > launches a console application (e.g. addr2line), a console
 > > > window is created for that application.
 > > 
 > > But addr2line isn't a console application; it simply writes to stdout.
 > 
 > It is - and so is c++filt. The "console" part refers not to a GUI
 > console but to something more like a dumb TTY.
In which case, why is a window created? Runtime.exec() starts a
process with its stdin, stdout, and stderr attached to the parent
process. In this case, there is no way that the "console" can be used
to do I/O.
 > The "console" is what gives the application the standard stdout,
 > stderr and stdin streams. If an application does not use these
 > streams and gets its input from elsewhere (GUI events), then it can
 > be compiled with "-mwindows" (on MinGW) to omit the Command Prompt
 > window that would be shown otherwise.
 > 
 > If a GUI application spawns a console application, Windows will
 > launch the application with an attached console (a Command Prompt
 > window).
But that makes no sense in the context of Runtime.exec(), which
creates an instance of Process. The Java spec says:
"The created subprocess does not have its own terminal or console."
How much clearer can it be?
Andrew.