I know that Gimpel’s Lint products (PC-Lint and Flexelint) will identify unreachable code and unused / unreferenced modules. They both fall in the category of static analysis tools. I have no affiliation w/ Gimpel, just a satisfied long-term customer.
Does the existence of such a statement in a given program mean that the whole program is undefined or that behavior only becomes undefined once control flow hits this statement? Neither. The first condition is too strong and the second is too weak. Object access are sometimes sequenced, but the standard describes the behavior of … Read more
The first does not compile (you got an error), the second compiles (you just got a warning). That’s the difference. As to why Eclipse detects dead code, well, that’s just the convenience of an integrated development tool with a built-in compiler which can be finetuned more as opposed to JDK to detect this kind of … Read more
You could use a code coverage analysis tool for this and look for unused spots in your code. A popular tool for the gcc toolchain is gcov, together with the graphical frontend lcov (http://ltp.sourceforge.net/coverage/lcov.php). If you use gcc, you can compile with gcov support, which is enabled by the ‘–coverage’ flag. Next, run your application … Read more
There are two varieties of unused code: the local one, that is, in some functions some paths or variables are unused (or used but in no meaningful way, like written but never read) the global one: functions that are never called, global objects that are never accessed For the first kind, a good compiler can … Read more
The JLS section on unreachable code explains the rationale. Essentially, Java normally shouldn’t use conditional compilation like C routinely does with #ifdef, but there are some situations (such as debugging, and in particular backward binary compatibility) where allowing the compiler to entirely strip out code is needed, and so the specific construct if(false) is permitted … Read more
In Python you can find unused code by using dynamic or static code analyzers. Two examples for dynamic analyzers are coverage and figleaf. They have the drawback that you have to run all possible branches of your code in order to find unused parts, but they also have the advantage that you get very reliable … Read more
An Eclipse plugin that works reasonably well is Unused Code Detector. It processes an entire project, or a specific file and shows various unused/dead code methods, as well as suggesting visibility changes (i.e. a public method that could be protected or private).