Teach Yourself Borland C++ in 14 Days - portal

368 Day 10
NOTE
The results of changing optimization settings can vary widely. Each
application is different. Sometimes optimizing for size has a big impact
on the final executable file size; other times the difference is negligible.
The same is true of optimizing for speed.
Debugging
The Debugging section of the C++ page of the Project Options dialog box controls how the
compiler generates code for debugging sessions. This section has four options, which are
explained in the following sections. (I’ll discuss debugging operations in detail tomorrow.)
Debug Information
When the Debug information option is enabled, C++Builder will generate debug information
for the project. The debug information is stored in a separate file in the project’s
directory. The filename of the file containing the debug information has a .TDS extension.
For example, if you had a program with a project name MyApp, C++Builder would generate
a symbol file called MyApp.tds. This file is read by the debugger during debug sessions. If you
do not generate debug information, you will not be able to stop on breakpoints and inspect
variables during debugging. Put another way, you can’t debug your program unless you tell
C++Builder to generate debug information.
Line Number Information
The Line number information option tells C++Builder to generate line number information
for the project. Line number information is used by the debugger to allow you to step through
your code line by line. This option is automatically enabled when you have the Debug
Information option turned on (even though the check box doesn’t show it). You can,
however, turn debug information off and then turn line number information on. This will
allow you to set breakpoints and step through your code, but you won’t be able to inspect
any variables. The benefit is that your .tds file will be smaller. In reality, it is unlikely that
you will opt to turn debug information off and line numbering on.
Automatic Register Variables
When the Automatic Register Variables option is on, the compiler will make use of register
variables as it sees fit. The use of register variables allows for much faster code. Register
variables can, however, be a bit of a pain while debugging. The compiler might optimize
your variables during debugging, making the variable unavailable for inspection. When a
variable has been optimized, the watch window will display the message Variable ‘x’ has
been optimized and is not available when you attempt to inspect the variable.