Programs That Eat Programs

Software GR Feb 24, 2015

Transcript

1. Programs That Eat Programs Michael R. Bernstein February 24th, 2015 Software GR, Grand Rapids, MI w michaelrbernste.in t @mrb_bk
2. I’m Obsessed
3. I’m Obsessed
4. I’m Obsessed
5. I have a podcast
6. Static analysis is my day job
7. I live in College Park, Maryland
8. Programs That Eat Programs
9. Programs That Eat Programs
10. What Is A Program?
15. Programs
19. Math
20. Math is Cool
21. “Introduction to Lattices and Order” Davey & Priestley
22. “Ordered Sets and Complete Lattices: A Primer for Computer Science” Priestley
23. A ______ is a _______ with a _______
24. Partial Order
25. Set Theory
27. Partially Ordered Sets
29. Lattices
31. Monotonicity
32. Galois Connections
34. Very Cool Math
35. “Principles of Program Analysis” Nielson, Nielson & Hankin
36. What Is A Program?
37. Programs That Eat Programs
38. How Do You Eat One?
39. Interpreters
40. “Essentials of Programming Languages” Friedman & Wand
41. “Abstracting Abstract Machines” Van Horn and Might
42. From a concrete interpreter to an abstract interpreter
43. type Σ = (Exp,Env,Store,Kont) type Env = Var :-> Addr data Storable = Clo (Lambda, Env) type Store = Addr :-> Storable data Kont = Mt | Ar (Exp,Env,Kont) | Fn (Lambda,Env,Kont) type Addr = Int
44. step :: Σ -> Σ step (Ref x, ρ, σ, κ) = (Lam lam, ρ', σ, κ) where Clo (lam, ρ') = σ!(ρ!x) step (f :@ e, ρ, σ, κ) = (f, ρ, σ, Ar(e, ρ, κ)) step (Lam lam,ρ,σ,Ar(e, ρ', κ)) = (e, ρ', σ, Fn(lam, ρ, κ)) step (Lam lam,ρ,σ,Fn(x :=> e, ρ', κ)) = (e, ρ' // [x ==> a'], σ // [a' ==> Clo (lam, ρ)], κ) where a' = alloc(σ)
46. Static Analysis
47. As long as we’ve been writing programs, we’ve been writing programs to analyze our programs
48. As long as we’ve been writing programs, we’ve been writing programs that eat programs
49. What Do We Hope To Learn?
51. State space exploration
55. Soundness
56. “In Defense of Soundiness: A Manifesto” Livshits, Sridharan,et. al.
57. Soundiness
58. Higher-Order PLs
59. Practicality
60. Semantics Matter!
61. Brakeman - Rails Security Scanner
62. The Future
63. SMT Solvers
64. Why write code and then generate proofs when you could write proofs and generate code?
65. Takeaways
66. Works Cited https://gist.github.com/mrb/e015c37e2b851be2b6ae
67. Thank You w michaelrbernste.in t @mrb_bk