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name: find-code description: Find where features, modes, commands, or messages are implemented in the ArduPilot codebase. Use when the user asks where something is defined, implemented, or handled. argument-hint: "<feature, mode, command, or message>" allowed-tools: Read, Grep, Glob

Find ArduPilot Code

Find the implementation of $ARGUMENTS in the ArduPilot codebase.

IMPORTANT: Use the built-in Grep and Glob tools, NOT shell grep or find commands.

Search strategies by type

Flight modes

Flight modes are classes in vehicle directories:

Glob: ArduCopter/mode_*.cpp
Glob: ArduPlane/mode_*.cpp
Glob: Rover/mode_*.cpp

Mode classes inherit from Mode and are defined in mode.h:

Grep for: class Mode.*$ARGUMENTS

Mode enum values:

Grep for: $ARGUMENTS in ArduCopter/mode.h or ArduPlane/mode.h

MAVLink message handlers

Incoming messages dispatched in GCS_MAVLINK:

Grep for: case MAVLINK_MSG_ID_$ARGUMENTS
Grep for: handle_message_$ARGUMENTS

Features / subsystems

Library implementations in libraries/:

Grep for: class.*$ARGUMENTS in libraries/**/*.h

Singleton access:

Grep for: AP::$ARGUMENTS
Grep for: $ARGUMENTS::get_singleton

Vehicle-specific features

Check the vehicle's main header and cpp files:

Grep for: $ARGUMENTS in ArduCopter/Copter.h
Grep for: $ARGUMENTS in ArduCopter/*.cpp

Parameters

Parameter definitions (use /find-param for detailed search):

Grep for: @Param:.*$ARGUMENTS
Grep for: AP_GROUPINFO.*"$ARGUMENTS"

Scheduler tasks

Tasks registered in vehicle scheduler:

Grep for: SCHED_TASK.*$ARGUMENTS
Grep for: $ARGUMENTS in ArduCopter/Copter.cpp (scheduler_tasks array)

RC auxiliary functions

Auxiliary switch functions:

Grep for: $ARGUMENTS in libraries/RC_Channel/RC_Channel.h
Grep for: case.*$ARGUMENTS in libraries/RC_Channel/RC_Channel.cpp

Log messages

Log message definitions:

Grep for: $ARGUMENTS in libraries/AP_Logger/LogStructure.h
Grep for: Write_$ARGUMENTS in libraries/**/*.cpp

Build options / feature flags

Compile-time enables:

Grep for: $ARGUMENTS in Tools/scripts/build_options.py
Grep for: #if.*$ARGUMENTS in libraries/**/*.h

Search tips

• Start broad with Grep across the whole repo, then narrow down
• Use Glob to find files by naming convention first, then Read specific files
• Check .h files for declarations, .cpp for implementations
• ArduPilot uses _enabled suffix for feature guards: AP_FEATURE_ENABLED
• Singleton classes: look for _singleton member and get_singleton() method
• Frontend/backend split: frontend in AP_Foo.h, backends in AP_Foo_Backend*.h