Use the Win32 Debug target until your program is fully debugged and you are ready to build a Win32 Release target. When you create a new project, select the Win32 Debug target. To turn on optimization in a Debug build configuration

In that case, you must debug the optimized code. However, a bug might appear only in an optimized version of a program. By default, optimization is turned off in the Debug configuration of a C++ program and turned on in the Release configuration. If you have a pointer to a structure and the value of the pointer is correct, every member variable of the structure will show the correct value.īecause of these limitations, you should debug using an unoptimized version of your program if at all possible. Global and static variables are always shown correctly. The frames on the call stack will be wrong if you have stack corruption, if you have functions written in assembly language, or if there are operating system frames without matching symbols on the call stack.

The frames that you see on the call stack are almost always correct, however, assuming you have symbols for all frames. Positions inside a function, which are changed when the optimizer merges blocks of code.įunction names for frames on the call stack, which might be wrong if the optimizer merges two functions. Local variables, which can be removed by the optimizer or moved to locations the debugger does not understand.

Because of this rearrangement, the debugger cannot always identify the source code that corresponds to a set of instructions. This results in more efficient compiled code. When the compiler optimizes code, it repositions and reorganizes instructions. This includes improved support for debugging local variables and inlined functions.Įdit and Continue is disabled when the /Zo ocompiler option is used. The /Zo (Enhance Optimized Debugging)compiler option (introduced in Visual Studio Update 3) generates richer debugging information for optimized code (projects that are not built with the /Od compiler option.

Visual studio compiler optimization