Centralized Exiting

Centralized Exiting#

In this project, functions should have a single, centralized exit point whenever possible. Centralized exiting improves readability, simplifies debugging, and ensures proper cleanup of resources, such as freeing memory or closing file handles, before the function returns.

Guidelines#

  • One Return Statement: Aim to have only one return statement at the end of the function to centralize the exit point.

  • Early Exits for Error Handling: While centralized exiting is preferred, early exits for error handling can be acceptable if they improve clarity. However, ensure that the function still handles resource cleanup properly before exiting early.

  • Use Helper Functions: If a function becomes too complex with a single exit point, consider breaking it into smaller helper functions to keep each function simple and readable.

Correct Example:

int my_function(int input)
{
  int result = 0;

  /* Check for errors early */
  if (input < 0) {
    return -1; /* Early exit for error handling */
  }

  /* Process input */
  result = input * 2;

  /* Perform any necessary cleanup */

  return result; /* Single, centralized return point */
}

Incorrect Example:

int my_function(int input)
{
  int result = 0;

  /* Check for errors */
  if (input < 0) {
    return -1; /* Return too early without cleanup */
  }

  /* Process input */
  if (input == 0) {
    return 0; /* Multiple return points */
  }

  result = input * 2;

  return result;
}

Resource Cleanup#

When centralized exiting is used, it makes it easier to ensure that all resources, such as memory or file handles, are properly cleaned up before exiting the function.

  • Handle Resource Cleanup: Before the centralized exit point (the final return), ensure that any resources allocated during the function (e.g., memory, file handles, network connections) are properly cleaned up.

Correct Example with Resource Cleanup:

int process_file(const char *file_name)
{
  FILE *file = fopen(file_name, "r");
  if (!file) {
    return -1; /* Early exit if file can't be opened */
  }

  /* Process the file here */

  fclose(file); /* Cleanup resource */
  return 0; /* Single exit point after resource cleanup */
}

General Guidelines#

  • Use a single return statement at the end of the function when possible.

  • Allow early exits for error handling, but ensure proper cleanup of resources.

  • Break complex functions into smaller helper functions if needed.

  • Always handle resource cleanup before the final exit.

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