Source
pub fn call_wWinMain() std.os.windows.INT {
const peb = std.os.windows.peb();
const MAIN_HINSTANCE = @typeInfo(@TypeOf(root.wWinMain)).@"fn".params[0].type.?;
const hInstance = @as(MAIN_HINSTANCE, @ptrCast(peb.ImageBaseAddress));
const lpCmdLine: [*:0]u16 = @ptrCast(peb.ProcessParameters.CommandLine.Buffer);
// There are various types used for the 'show window' variable through the Win32 APIs:
// - u16 in STARTUPINFOA.wShowWindow / STARTUPINFOW.wShowWindow
// - c_int in ShowWindow
// - u32 in PEB.ProcessParameters.dwShowWindow
// Since STARTUPINFO is the bottleneck for the allowed values, we use `u16` as the
// type which can coerce into i32/c_int/u32 depending on how the user defines their wWinMain
// (the Win32 docs show wWinMain with `int` as the type for nCmdShow).
const nCmdShow: u16 = nCmdShow: {
// This makes Zig match the nCmdShow behavior of a C program with a WinMain symbol:
// - With STARTF_USESHOWWINDOW set in STARTUPINFO.dwFlags of the CreateProcess call:
// - Compiled with subsystem:console -> nCmdShow is always SW_SHOWDEFAULT
// - Compiled with subsystem:windows -> nCmdShow is STARTUPINFO.wShowWindow from
// the parent CreateProcess call
// - With STARTF_USESHOWWINDOW unset:
// - nCmdShow is always SW_SHOWDEFAULT
const SW_SHOWDEFAULT = 10;
const STARTF_USESHOWWINDOW = 1;
// root having a wWinMain means that std.builtin.subsystem will always have a non-null value.
if (std.builtin.subsystem.? == .Windows and peb.ProcessParameters.dwFlags & STARTF_USESHOWWINDOW != 0) {
break :nCmdShow @truncate(peb.ProcessParameters.dwShowWindow);
}
break :nCmdShow SW_SHOWDEFAULT;
};
// second parameter hPrevInstance, MSDN: "This parameter is always NULL"
return root.wWinMain(hInstance, null, lpCmdLine, nCmdShow);
}