DebuggableAttribute.DebuggingModes Enumeration

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Specifies the debugging mode for the just-in-time (JIT) compiler.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

Namespace:  System.Diagnostics
Assembly:  mscorlib (in mscorlib.dll)

public enum DebuggingModes

Member nameDescription
NoneA value specifying that the debugging mode is not specified.
DefaultInstructs the just-in-time (JIT) compiler to use its default behavior, which includes enabling optimizations, disabling Edit and Continue support, and using symbol store sequence points if present.
DisableOptimizationsDisable optimizations performed by the compiler to make your output file smaller, faster, and more efficient. Optimizations result in code rearrangement in the output file, which can make debugging difficult. Typically optimization should be disabled while debugging.
IgnoreSymbolStoreSequencePointsUse the implicit MSIL sequence points, not the program database (PDB) sequence points. The symbolic information normally includes at least one Microsoft intermediate language (MSIL) offset for each source line. When the just-in-time (JIT) compiler is about to compile a method, it asks the profiling services for a list of MSIL offsets that should be preserved. These MSIL offsets are called sequence points.
EnableEditAndContinueEnable edit and continue. Edit and continue enables you to make changes to your source code while your program is in break mode. The ability to edit and continue is compiler dependent.

The DebuggableAttribute..::..DebuggingModes enumeration specifies how the runtime is to track information important to the debugger during code generation. This information helps the debugger provide a rich debugging experience.

Sequence points are used to indicate locations in the Microsoft intermediate language (MSIL) code that a debugger user will expect to be able to refer to uniquely, such as for setting a breakpoint. The JIT compiler ensures it does not compile the MSIL at two different sequence points into a single native instruction. By default, the JIT compiler examines the symbol store in the program database (PDB) file for a list of additional sequence points. However, loading the PDB file requires that the file be available and has a negative performance impact.


This enumeration is primarily used by language developers. It is generally not used in application development. Development environments use DebuggableAttribute..::..DebuggingModes based on compiler parameters such as /debug and /optimize.