02247 Compilers Project

We used the llvm pass skeleton from here cloned from here. It is released under the MIT license. See SKELETON-LICENSE.

Build:

$ mkdir build
$ cd build
$ cmake ..
$ make
$ cd ..

Run:

# Run manually:
$ clang -Xclang -load -Xclang build/skeleton/libNullDereferenceDetection.* examples/hello.c

# Or use one of the bash scripts:
$ ./opt <folder>/<example>            # compile with clang and run with opt
$ ./compile <folder>/<example>        # compile and run pass with clang

Possible null detections

• Null detection for local variables within a function. If a variable with a pointer type has 0 assigned to it, then track it and warn when dereferenced. (done)
• Detect null check: stop complaining if a null check has been done. (interesting, but not done)
• Track maybe null return values. Analyse a function implementation to see if there exists a possibility of null. (done, but no warnings)