Implement on demand stdio allocation

COREDLL/Exports.def

@@ -31,7 +31,7 @@ EXPORTS
 	_wcsupr @232
 	vfwprintf=vfwprintf_WCECL @721
 	fflush @1122
-	fgetws=fgetws_WCECL @1143
+	fgetws @1143
 	fputwc @1141
 	fputws @1144
 	_getstdfilex=_getstdfilex_WCECL @1100

COREDLL/other.cpp

@@ -196,6 +196,12 @@ void CeLogSetZones(DWORD dwZoneUser,        // User-defined zones
 
 void* _fileno_WCECL(FILE* file)
 {
+	void* result = WceclTryGetOrAllocStdHandle(file);
+	if (result != NULL)
+	{
+		return result;
+	}
+
 	return (void*)_get_osfhandle(_fileno(file));
 }
 
@@ -220,22 +226,6 @@ int WINAPI WideCharToMultiByte_WCECL(
 		lpUsedDefaultChar);
 }
 
-wchar_t* fgetws_WCECL(wchar_t* w, int count, FILE* file)
-{
-	wchar_t* result = fgetws(w, count, file);
-	if (result == NULL && 
-		file == stdin && count > 2)
-	{
-		result = w;
-		wsprintf(w, L"");
-	}
-	else
-	{
-		return result;
-	}
-	return result;
-}
-
 // Stubs
 Stub(_chkstk_WCECL);
 Stub(WaitForAPIReady);

COREDLL/stdio_wcecl.cpp

@@ -2,6 +2,47 @@
 #include <assert.h>
 #include <io.h>
 
+/* https://learn.microsoft.com/en-us/windows/console/clearing-the-screen */
+static BOOL WceclConsoleClearScreen(
+	HANDLE hDevice)
+{
+	CHAR_INFO charInfo;
+	COORD scrollTarget;
+	SMALL_RECT scrollRect;
+	CONSOLE_SCREEN_BUFFER_INFO screenInfo;
+
+	if (!GetConsoleScreenBufferInfo(hDevice, &screenInfo))
+	{
+		return FALSE;
+	}
+
+	charInfo.Char.UnicodeChar = L' ';
+	charInfo.Attributes = screenInfo.wAttributes;
+
+	scrollRect.Left = 0;
+	scrollRect.Top = 0;
+	scrollRect.Right = screenInfo.dwSize.X;
+	scrollRect.Bottom = screenInfo.dwSize.Y;
+
+	scrollTarget.X = 0;
+	scrollTarget.Y = -screenInfo.dwSize.Y;
+
+	if (ScrollConsoleScreenBufferW(
+			hDevice,
+			&scrollRect,
+			NULL,
+			scrollTarget,
+			&charInfo) == 0)
+	{
+		return FALSE;
+	}
+
+	screenInfo.dwCursorPosition.X = 0;
+	screenInfo.dwCursorPosition.Y = 0;
+
+	SetConsoleCursorPosition(hDevice, screenInfo.dwCursorPosition);
+}
+
 static DWORD GetWin32ConsoleModeFromWce(DWORD wceConsoleMode)
 {
 	DWORD out = 0;
@@ -102,6 +143,44 @@ static BOOL WceclConsoleGetTitle(
 	return GetConsoleTitleA(lpOutBuf, nOutBufSize);
 }
 
+
+static BOOL WceclConsoleGetRowsCols(
+	HANDLE hDevice,
+	PDWORD lpCols,
+	PDWORD lpRows,
+	DWORD nOutBufSize)
+{
+	CONSOLE_SCREEN_BUFFER_INFO screenInfo;
+	DWORD win32ConsoleMode;
+	BOOL result;
+
+	if (nOutBufSize < sizeof(DWORD))
+	{
+		return FALSE;
+	}
+
+	if (!GetConsoleScreenBufferInfo(hDevice, &screenInfo))
+	{
+		return FALSE;
+	}
+
+	if (lpRows != NULL)
+	{
+		*lpRows = screenInfo.dwSize.Y;
+	}
+	if (lpCols != NULL)
+	{
+		*lpCols = screenInfo.dwSize.X;
+	}
+	if (lpCols == NULL && lpRows == NULL)
+	{
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+
 BOOL WceclConsoleIoControl(
 	HANDLE hDevice,
 	DWORD dwIoControlCode,
@@ -123,8 +202,13 @@ BOOL WceclConsoleIoControl(
 	case IOCTL_CONSOLE_GETTITLE:
 		return WceclConsoleGetTitle((LPSTR)lpOutBuf, nOutBufSize);
 	case IOCTL_CONSOLE_CLS:
-		/* TODO */
-		return TRUE;
+		return WceclConsoleClearScreen(hDevice);
+	case IOCTL_CONSOLE_FLUSHINPUT:
+		return FlushConsoleInputBuffer(hDevice);
+	case IOCTL_CONSOLE_GETSCREENROWS:
+		return WceclConsoleGetRowsCols(hDevice, NULL, (PDWORD)lpOutBuf, nOutBufSize);
+	case IOCTL_CONSOLE_GETSCREENCOLS:
+		return WceclConsoleGetRowsCols(hDevice, (PDWORD)lpOutBuf, NULL, nOutBufSize);
 	default:
 		/* TODO */
 		return FALSE;
@@ -182,4 +266,110 @@ BOOL WINAPI GetStdioPathW_WCECL(
 	}
 
 	return FALSE;
+}
+
+static BOOL WceclTryGetStdHandle(FILE* file, PHANDLE handle)
+{
+	if (file == stdin)
+	{
+		*handle = GetStdHandle(STD_INPUT_HANDLE);
+	}
+	else if (file == stdout)
+	{
+		*handle = GetStdHandle(STD_OUTPUT_HANDLE);
+	}
+	else if (file == stderr)
+	{
+		*handle = GetStdHandle(STD_ERROR_HANDLE);
+	}
+	else
+	{
+		return FALSE;
+	}
+	return TRUE;
+}
+
+static BOOL WceclAllocateStdio()
+{
+	HWND hWndConsole;
+	BOOL bConsoleAllocated;
+
+	HANDLE hOldStdIn, hOldStdOut, hOldStdErr;
+
+	hWndConsole = GetConsoleWindow();
+
+	hOldStdIn = GetStdHandle(STD_INPUT_HANDLE);
+	hOldStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
+	hOldStdErr = GetStdHandle(STD_ERROR_HANDLE);
+
+	if (hWndConsole == NULL)
+	{
+		AllocConsole();
+		hWndConsole = GetConsoleWindow();
+
+		if (hWndConsole == NULL)
+		{
+			return FALSE;
+		}
+
+		bConsoleAllocated = TRUE;
+	}
+	else
+	{
+		bConsoleAllocated = FALSE;
+	}
+
+	assert(hOldStdErr == NULL || hOldStdIn == NULL || hOldStdOut == NULL);
+
+	if (hOldStdIn == NULL)
+	{
+		if (freopen("CONIN$", "r", stdin) == NULL)
+		{
+			goto CLEANUP;
+		}
+	}
+	if (hOldStdOut == NULL)
+	{
+		if(freopen("CONOUT$", "w", stdout) == NULL)
+		{
+			goto CLEANUP;
+		}
+	}
+	if (hOldStdErr == NULL)
+	{
+		if(freopen("CONERR$", "w", stderr) == NULL)
+		{
+			goto CLEANUP;
+		}
+	}
+
+	return TRUE;
+CLEANUP:
+	if (bConsoleAllocated)
+	{
+		FreeConsole();
+	}
+	return FALSE;
+}
+
+/* It seems that CE programs launch a console only when it is about to be
+   used. */
+HANDLE WceclTryGetOrAllocStdHandle(FILE* file)
+{
+	HANDLE hFile;
+
+	if (WceclTryGetStdHandle(file, &hFile) == FALSE)
+	{
+		return NULL;
+	}
+
+	if (hFile == NULL)
+	{
+		if (WceclAllocateStdio() == FALSE)
+		{
+			return FALSE;
+		}
+	}
+
+	return hFile;
 }

COREDLL/stdio_wcecl.h

@@ -0,0 +1,32 @@
+#pragma once
+#include "stdafx.h"
+
+#define FILE_DEVICE_CONSOLE 0x0102
+
+#define CECONSOLE_MODE_ECHO_INPUT 0x01
+#define CECONSOLE_MODE_LINE_INPUT 0x02
+#define CECONSOLE_MODE_PROCESSED_OUTPUT 0x04
+
+#define CONSOLE_CTL(i) ((FILE_DEVICE_CONSOLE<<16)|(i << 2))
+#define IOCTL_CONSOLE_SETMODE				CONSOLE_CTL(1)
+#define IOCTL_CONSOLE_GETMODE				CONSOLE_CTL(2)
+#define IOCTL_CONSOLE_SETTITLE				CONSOLE_CTL(3)
+#define IOCTL_CONSOLE_GETTITLE				CONSOLE_CTL(4)
+#define IOCTL_CONSOLE_CLS					CONSOLE_CTL(5)
+#define IOCTL_CONSOLE_FLUSHINPUT			CONSOLE_CTL(6)
+#define IOCTL_CONSOLE_GETSCREENROWS			CONSOLE_CTL(7)
+#define IOCTL_CONSOLE_SETCONTROLCHANDLER	CONSOLE_CTL(8)
+#define IOCTL_CONSOLE_GETSCREENCOLS			CONSOLE_CTL(9)
+#define IOCTL_CONSOLE_SETCONTROLCEVENT      CONSOLE_CTL(10)
+
+BOOL WceclConsoleIoControl(
+	HANDLE hDevice,
+	DWORD dwIoControlCode,
+	LPVOID lpInBuf,
+	DWORD nInBufSize,
+	LPVOID lpOutBuf,
+	DWORD nOutBufSize,
+	LPDWORD lpBytesReturned,
+	LPOVERLAPPED lpOverlapped);
+
+HANDLE WceclTryGetOrAllocStdHandle(FILE* file);