# User:Realazthat/Projects wishlist/LLVM/Formal methods

< User:Realazthat | Projects wishlist | LLVM

## Features[edit]

Follow the examples of wp:Java_Modeling_Language and wp:SPARK_programming_language.

Things that the pass might prove, for each function:

- That all
**assert**statements can not occur, or complain otherwise (if an**assert**statement cannot be proved to not fail)- LLVM and assert/assume: http://llvm.org/bugs/show_bug.cgi?id=810

- Determine if the function requires Turing-completeness
- wp:Termination_analysis
- Reduction of turing-ness if possible (if provable) to decidable
- Do some
**good stuff**, as the function is not Turing-complete - Equivalence?
- Allow a function to assert only co-recursion (no requirement for Turing-completeness)
- Probably requires that the function is rewritable in non-Turing-complete, and thus requires that the function not require Turing-completeness

- Compute function complexity (best, average, worst) of an algorithm (function)
- Allow the function to assert complexity

- Allow arbitrary restrictions on functions, which would propagate through the call graph
- Complexity (time/memory)
- Restricting stack allocation
- Restricting heap allocation

- Allow a programmer to make certain assumptions on input (probably through assertions)
- Prove that no
**undefined behavior**can occur- Math overflows/underflows
- Out of bounds access
- Memory leaks
- Dangling pointers
- etc.

- Null dereferencing
- What else

- Determine valid input ranges (if the type of the input does not already assert this)
- Show proofs for all of the above
- Create Proof-carrying code

- Impossible stuff
- Be able to calculate a function inverse if possible
- Hmmmm

- Transformation of function to set of equivalent functions
- Hmmmm

- Be able to calculate a function inverse if possible
- Side effect free functions
- Pure functions
- Reentrant functions
- No deadlocks etc.
- If any of the above can't be proven, show test counter examples; that is exploitable input
- Related
- http://seanhn.files.wordpress.com/2009/09/thesis1.pdf
- A thesis on finding exploiting input using SMT

- Fun uses for an SMT solver
- Using SMT to find exploitable input, blog post, by thesis author

- Applying Taint Analysis and Theorem Proving to Exploit Development
- Another blog post, by thesis author

- http://seanhn.files.wordpress.com/2009/09/thesis1.pdf

- Related