suicide cc

A common illustrative example of something undefined behavior in C can do is "format your hard drive". Suicide CC is a LLVM pass which implements this. When compiling with this pass enabled, each function is checked for 1 type of undefined behavior. If it is found, the pass emits code which executes an arbitrary shell command using system().

The scope of detected undefined behavior is simply local uses of uninitialized stack variables of primitive type. It should support most POSIX like operating systems.

This project is named for its similarity to Suicide Linux.

Note: For the safety of my dev machine, the pass in this source tree is declawed such that it will only emit code to delete a very specific file from the system executing the program. However, to achieve the fully advertised functionality, simply reassign Suicide::SYSTEM_CMD in Suicide.cc to your choice of hard drive erasing shell command.

demo

(slightly out of date)

building

Install LLVM 3.8.

To build the test program and pass.

make

To run the pass on the test program.

make check

misc

• "SURE" means there is a code path between allocation of a stack variable, and a read of it, before any writes to it
• "UNSURE" means that in between the code path between allocation of a stack variable, and a read of it, a pointer to that variable is passed into at least one function
• in some cases, "SURE" warnings might be misclassified as "UNSURE". this occurs when the analysis encounters an "UNSURE" path before a "SURE" path involving the same variable and memory read