Manipulate Function Call Sites

Learn how to manipulate function call sites with Codegen

Codegen’s GraphSitter library provides powerful APIs for systematically manipulating function call sites throughout your codebase.

This guide will walk you through the basics of working with function call sites using GraphSitter.

Common use cases include:

• Updating function calls after changing function signatures
• Refactoring to use named arguments
• Adding or removing arguments from function calls

Overview

To manipulate function call sites, you first need to locate them. You can do this using the call_sites property of a function.

# Grab a specific function definition
function = codebase.get_file("path/to/file.py").get_function("my_function")

# Iterate over all call sites
for call_site in function.call_sites:

    # Insert a new keyword argument
    call_site.insert_argument("new_arg=42")

    # Look at existing arguments
    for arg in call_site.args:

        # Remove an argument
        if arg.name == 'existing_arg':
            arg.remove()

        # Rename an argument
        elif arg.name == 'arg_to_rename':
            arg.set_name('new_arg_name')

        # Modify an argument value
        elif arg.name == 'arg_to_modify':
            arg.set_value('42')

Modifying Arguments

You can add, remove, or modify arguments at a call site:

# Add a new argument
call_site.insert_argument("new_arg=42")

# Remove an argument
arg_to_remove = call_site.get_arg_by_parameter_name("old_arg")
arg_to_remove.remove()

# Modify an existing argument
arg_to_modify = call_site.get_arg_by_parameter_name("existing_arg")
arg_to_modify.edit("existing_arg='new_value'")

Converting to Named Arguments

You can convert positional arguments to named arguments:

call_site.convert_args_to_kwargs()

This will convert all positional arguments to named arguments, based on the parameter names in the function definition.

Updating Multiple Call Sites

If you need to update multiple call sites, you can do so in a loop:

function = codebase.get_file("path/to/file.py").get_function("my_function")

for call_site in function.call_sites:
    # Add a new argument to all call sites
    call_site.insert_argument("new_arg=42")

Handling Different Argument Types

GraphSitter allows you to handle different types of arguments:

for arg in call_site.args:
    if arg.is_named:
        # Handle named argument
        print(f"Named arg: {arg.name} = {arg.value}")
    else:
        # Handle positional argument
        print(f"Positional arg: {arg.value}")

Best Practices

1. Commit After Major Changes: If you’re making multiple significant changes, use codebase.commit() between them to ensure the codebase graph is up-to-date.

2. Re-fetch References: After a commit, re-fetch any file or symbol references you’re working with, as they may have become stale.

3. Handle Errors: Be prepared to handle cases where functions or call sites might not exist, or where modifications might fail due to syntax errors.

By following these guidelines, you can effectively manipulate function call sites throughout your codebase while maintaining its integrity and functionality.