On Thursday, 7 June 2018 at 19:19:55 UTC, realhet wrote:
Hi,
The following narrow test program works fine when compiled with
DMD to 32bit target:
import std.stdio, core.sys.windows.windows, core.runtime;
extern(Windows) int WinMain(HINSTANCE hInstance, HINSTANCE
hPrevInstance, LPSTR lpCmdLine, int iCmdShow)
{
Runtime.initialize;
writeln("Hello");
stdout.flush; //exception
readln; //exception
return 0;
}
It shows the console window and waits for user input at readln.
If I try to compile this to 64bit target or with LDC (both 32
and 64) it gets privileged instruction exception at
stdout.flush. If I comment out flush then it fails at readln.
I get no exceptions with this code, but if I run if I compile
with no flags, it prints hello and waits for input. With
-m32mscoff or -m64, there's no output. If I run from Windows
Explorer, the no-flag version pops up a console, prints and
waits, while the -m32mscoff and do nothing.
As Steven mentioned earlier, this is a runtime issue. The
standard I/O streams are not available in the MSVC runtime by
default when compiling as a GUI application. You don't have to
enable any flags to get that -- it's automatic when WinMain is
present. The DititalMars runtime, which is what you get with the
default compile, apparently does initialize the standard I/O
streams and makes sure the console pops up when you write to it.
Is there a way to fix this? I don't wanna lose the console
window even on 64bit.
If you want to keep WinMain and still have the console stuff
available from the start with the MSVC runtime, you can get it
with this:
dmd -m64 -L/SUBSYSTEM:console -L/ENTRY:WinMainCRTStartup foo.d
With this (for -m32mscoff as well), the above code runs the same
as it does with the DigitalMars runtime.
