Cleaned up Windows logging code.

src/driver.h

@@ -22,7 +22,7 @@ void FCEUD_GetPalette(uint8 i,uint8 *r, uint8 *g, uint8 *b);
 
 /* Displays an error.  Can block or not. */
 void FCEUD_PrintError(char *s);
-void FCEUD_Message(char *s);
+void FCEUD_Message(const char *s);
 
 /* Network interface */
 

src/drivers/win/log.cpp

@@ -3,104 +3,189 @@
 
 static HWND logwin = 0;
 
-static char *logtext[64];
+static char *logtext[MAXIMUM_NUMBER_OF_LOGS];
-static int logcount=0;
+static unsigned int logcount=0;
 
-static void RedoText(void)
+unsigned int truncated_logcount()
 {
- char textbuf[65536];
+	return logcount & ( MAXIMUM_NUMBER_OF_LOGS - 1 );
- int x;
+}
 
- textbuf[0]=0;
+/**
- if(logcount>=64)
+* Concatenates formerly logged messages into a single string and
+* displays that string in the log window.
+*
+* TODO: This function contains a potential buffer overflow
+**/
+void RedoText(void)
 {
-  x=logcount&63;
+	char textbuf[65536] = { 0 };
+	unsigned int x;
+
+	// TODO: This if can be made much simpler.
+	if(logcount >= MAXIMUM_NUMBER_OF_LOGS)
+	{
+
+		x = truncated_logcount();
+
 		for(;;)
 		{
 			strcat(textbuf, logtext[x]);
-   x=(x+1)&63;
+			x = ( x + 1 ) & ( MAXIMUM_NUMBER_OF_LOGS - 1 );
-   if(x==(logcount&63)) break;
+
+			if(x == truncated_logcount())
+			{
+				break;
+			}
 		}
 	}
 	else
+	{
 		for(x = 0; x < logcount; x++)
 		{
 			strcat(textbuf,logtext[x]);
 		}
+	}
+
 	SetDlgItemText(logwin, 100, textbuf);
 	SendDlgItemMessage(logwin, 100, EM_LINESCROLL, 0, 200);
 }
 
-static BOOL CALLBACK LogCon(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
+/**
+* Callback function for the log window.
+**/
+BOOL CALLBACK LogCon(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
 	DSMFix(uMsg);
+
 	switch(uMsg)
 	{
-   case WM_INITDIALOG:logwin=hwndDlg;
+		case WM_INITDIALOG:
-                      RedoText();break;
+            RedoText();
+			break;
 		case WM_COMMAND:
 			if(HIWORD(wParam)==BN_CLICKED)
 			{
 				DestroyWindow(hwndDlg);
+
+				// Clear the handle
 				logwin = 0;
 			}
 			break;
-
 	}
+
 	return 0;
 }
 
+/**
+* Creates the log window if it's not already open.
+**/
 void MakeLogWindow(void)
 {
 	if(!logwin)
-  CreateDialog(fceu_hInstance,"MESSAGELOG",0,LogCon);
+	{
+		logwin = CreateDialog(fceu_hInstance, "MESSAGELOG" , 0, LogCon);
+	}
 }
 
-void AddLogText(char *text,int newline)
+/**
+* Adds a textual log message to the message buffer.
+*
+* @param text Message to add.
+* @param add_newline Either DO_ADD_NEWLINE or DONT_ADD_NEWLINE
+**/
+void AddLogText(const char *text, unsigned int add_newline)
 {
- int x;
+	// Used to count the number of new line characters in text
- char *t;
+	int number_of_newlines;
 
- if(logcount>=64) free(logtext[logcount&63]);
+	// Used to iterate over the text
+	const char *text_iterator_c;
 
- x=0;
+	// Used to iterate over the message log created in this function
- t=text;
+	char* msg_iterator;
- while(*t)
+
+	// Free a log message if more messages than necessary were logged.
+	if(logcount >= MAXIMUM_NUMBER_OF_LOGS)
 	{
-  if(*t=='\n') x++;
+		free(logtext[truncated_logcount()]);
-  t++;
 	}
 
- if(!(logtext[logcount&63]=(char*)malloc(strlen(text)+1+x+newline*2))) //mbg merge 7/17/06 added cast
+	number_of_newlines = 0;
+	text_iterator_c = text;
+
+	// Count the number of \n characters in the text
+	while(*text_iterator_c)
+	{
+		if(*text_iterator_c == '\n')
+		{
+			number_of_newlines++;
+		}
+
+		text_iterator_c++;
+	}
+
+	unsigned int necessary_size = strlen(text) // len(text)
+		+ 1 // 0-byte
+		+ number_of_newlines // Space for additional \r characters
+		+ 2 * add_newline; // \r\n if a newline was requested
+
+	//mbg merge 7/17/06 added cast
+	logtext[truncated_logcount()] = (char*)malloc(necessary_size);
+
+	// Apparently there's no memory left.
+	if(!logtext[truncated_logcount()])
+	{
 		return;
+	}
 
- t=logtext[logcount&63];
+	msg_iterator = logtext[truncated_logcount()];
 
+	// Copy the characters from text to the allocated buffer
 	while(*text)
 	{
+		// Replace \n with \r\n
 		if(*text == '\n')
 		{
-   *t='\r';
+			*msg_iterator='\r';
-   t++;
+			msg_iterator++;
-  }
-  *t=*text;
-  t++;
-  text++;
- }
- if(newline)
- {
-  *t='\r';
-  t++;
-  *t='\n';
-  t++;
- }
- *t=0;
- logcount++;
- if(logwin)
-  RedoText();
 		}
 
-void FCEUD_Message(char *text)
+		*msg_iterator = *text;
-{
+
- AddLogText(text,0);
+		msg_iterator++;
+		text++;
+	}
+
+	// Add a final newline if requested
+	if(add_newline)
+	{
+		*msg_iterator = '\r';
+		msg_iterator++;
+		*msg_iterator = '\n';
+		msg_iterator++;
+	}
+
+	// Terminating 0-byte
+	*msg_iterator = 0;
+
+	// Keep track of the added log
+	logcount++;
+
+	if(logwin)
+	{
+		RedoText();
+	}
+}
+
+/**
+* Adds a textual message to the message buffer without adding a newline at the end.
+*
+* @param text The text of the message to add.
+* 
+* TODO: This function should have a better name.
+**/
+void FCEUD_Message(const char *text)
+{
+	AddLogText(text, DONT_ADD_NEWLINE);
 }

src/drivers/win/log.h

@@ -1,2 +1,7 @@
+#define MAXIMUM_NUMBER_OF_LOGS 64
+
+#define DONT_ADD_NEWLINE 0
+#define DO_ADD_NEWLINE 1
+
 void MakeLogWindow(void);
-void AddLogText(char *text,int newline);
+void AddLogText(const char *text, unsigned int add_newline);

src/drivers/win/main.cpp

@@ -418,7 +418,7 @@ int main(int argc,char *argv[])
 
 	if(timeBeginPeriod(1) != TIMERR_NOERROR)
 	{
-	AddLogText("Error setting timer granularity to 1ms.",1);
+		AddLogText("Error setting timer granularity to 1ms.", DO_ADD_NEWLINE);
 	}
 
 	InitCommonControls();