Gcov - analyzing code produced with GCC

How can a programmer exactly know which part of his code is frequently executed and which part of code is never traversed ? That's where CODE COVERAGE comes for rescue ...

Code Coverage is a measure used in software testing to describe the degree to which the source code of a program has been tested. It is a form of testing that inspects the code directly and checks the active and non-active parts of the source-code.

Basically there are number of code coverage criteria, the main ones being:

• Function coverage
Has each function in the program been executed?


• Statement coverage
Has each line of the source code been executed?


• Decision coverage (also known as Branch coverage)
Has each control structure (such as an if statement) evaluated both to true
and false?


• Condition coverage
Has each boolean sub-expression evaluated both to true and false (this does
not necessarily imply decision coverage)?


• Modified Condition/Decision Coverage (MC/DC)
Has every condition in a decision taken on all possible outcomes at least
once? Has each condition been shown to affect that decision outcome
independently?


• Path coverage
Has every possible route through a given part of the code been executed?


• Entry/exit coverage
Has every possible call and return of the function been executed?