Debugger

Cardinal Debugger

Usage of the Debugger

When the engine is in debug mode: a script that is run will immediately stop to ask what it should do.

The given actions are:

• c to continue running
• s to step into
• n to move to the next step
• o to step out of the current function or fiber
• b to set a breakpoint
  • give the line number on which to place a breakpoint
• l to list items
  • b to list all breakpoints
  • v to list all local variables
  • m to list all member properties from the current object
  • g to list all global variables
  • s to list statistics from the VM (GC + host objects)
  • f to print the current stack
• r to remove a breakpoint
• w to check where you are
• a to abort execution
• h to print the help menu

Design of the Debugger

There is no exposing API that makes it possible to design an debugger without knowing/using any of the internals of the VM.

DebugState is an enum holding the current state of the debugger

• CONTINUE: continue until next break point
• STEP_INTO: stop at next instruction
• STEP_OVER: stop at next instruction, skipping called functions
• STEP_OUT: run until returning from current function
• DEFAULT