---

description: Trace callers and callees of a function or method across the codebase subtask: true

Trace call graph for: $ARGUMENTS

Steps:

1. Find the definition. If the target is a method on a C++ class, use the cross-reference tool first to locate the header, implementation files, and JSG registration in a single call. For Rust symbols (under src/rust/), search .rs files manually and check for CXX bridge declarations. Otherwise, search for the function/method definition manually. If the argument is ambiguous (e.g., a common name like get), ask for clarification or use the class-qualified form (e.g., IoContext::current).

2. Read the implementation. Read the function body to identify:

   • Direct callees: functions/methods called within the body
   • Filter out trivial calls (logging, assertions, simple getters) unless they're relevant to understanding the flow

3. Find callers. Search for call sites across the codebase:

   grep -rn '<function_name>' src/ --include='*.h' --include='*.c++' --include='*.rs'

   Filter to actual calls (not declarations, comments, or string literals). For methods, search for both ->methodName( and .methodName( patterns.

   For functions crossing the Rust/C++ FFI boundary (defined in a #[cxx::bridge] block or companion ffi.c++/ffi.h file), search both sides: a Rust function called from C++ will have callers in .c++ files and its declaration in the CXX bridge; a C++ function called from Rust will have its Rust callers in .rs files and its implementation in ffi.c++. Also check generated headers (<file>.rs.h) if the call path is unclear.

4. Build the call graph. Organize into:

   • Callers (who calls this function) — grouped by directory/component
   • Callees (what this function calls) — the significant ones from the implementation

5. Trace one level deeper if needed. If the argument includes "deep" or the function is a thin wrapper, trace one additional level in each direction to find the meaningful boundaries.

6. Output:

   • Function: full qualified name, file:line of definition
   • Callers (N call sites):
     • file:line — brief context of why it's called
   • Callees (N significant calls):
     • function_name (file:line) — brief description
   • Call flow summary: A brief narrative of how this function fits into the broader execution flow (e.g., "Called during request setup to initialize the I/O context, which then creates the worker lock...")
   • Limit to ~20 most important callers. If there are more, note the total count and list the most representative ones grouped by component.