Find Symbol Using ctags

Find Symbol Using ctags

This skill searches for symbol definitions (functions, structs, variables, classes) in the ctags indexes.

How It Works

The repository has two ctags indexes:

• Firmware (C code): inav/​tags
• Configurator (JS code): inav-configurator/​tags

Usage

When the user asks to find a symbol, search both indexes:

# Search firmware (C code)
grep "^SYMBOL_NAME\b" inav/​tags | head -20

# Search configurator (JS code)
grep "^SYMBOL_NAME\b" inav-configurator/​tags | head -20

Replace SYMBOL_NAME with the actual symbol to search for.

Parsing the Output

Each line in the tags file contains tab-separated fields:

1. Symbol name - The identifier being searched for
2. File path - Where the symbol is defined
3. Search pattern - Usually /^...$/ or line number
4. Extensions - Key-value pairs like kind:f, line:123, signature:(args)

Common kind values:

• f = function
• s = struct
• v = variable
• c = class
• m = member/​method
• t = typedef
• d = #define/​macro
• p = prototype

Reporting Results

Present the results in a clear format:

Found in firmware (C code):
- File: src/​main/​flight/​pid.c:145
  Kind: function
  Signature: void pidController(timeUs_t currentTimeUs)

- File: src/​main/​flight/​pid.h:23
  Kind: prototype

Found in configurator (JS code):
- File: js/​controllers/​configuration.js:89
  Kind: function

Use the format file_path:line_number to allow easy navigation.

Limitations

• JavaScript indexing is limited: ctags doesn't parse ES6+ features well

  • For JS code, Claude's built-in Grep tool often works better
  • Use Grep with pattern like: function.*symbolName or class symbolName

• C firmware indexing works well for functions, structs, variables, and macros

Regenerating Indexes

If source files have changed significantly and symbols aren't found:

# Firmware (C code)
cd inav
ctags -R --fields=+niazS --extras=+q --exclude=lib --exclude=build --exclude=tools --exclude=.git -f tags .

# Configurator (JS code)
cd inav-configurator
ctags -R --fields=+niazS --extras=+q --exclude=node_modules --exclude=.git --exclude=out --exclude=.vite --exclude=dist -f tags .

Examples

User asks: "Where is pidController defined?"

You should:

1. Run grep on both tags files with pattern ^pidController\b
2. Parse the results to extract file path and line number
3. Report in the format: src/​main/​flight/​pid.c:145

User asks: "Find the navConfig struct"

You should:

1. Search for ^navConfig\b in both indexes
2. Look for entries with kind:s (struct) or kind:t (typedef)
3. Report all matches with file locations

Related Skills

• wiki-search - Search documentation for implementation guidance
• msp-protocol - Look up MSP commands and structures