test-mass-forker-org-1 / aliveinlean

Formally verified implementation of Alive in Lean

AliveInLean

Setup

• Download Lean 3.4.2 from https://leanprover.github.io/download/
• Extract it, and update PATH environmental variable so command lean can be executed on the command prompt
• Download & install z3 from https://github.com/Z3Prover/z3 and update PATH so z3 can be executed as well
• Run leanpkg configure to install SMT lib interface and mathlib

Run

# Run selected tests from Alive's test suite (which contain
# no precondition and do not require additional grammars)
./run-alive.sh

# Run random tests for the specification of Z3 expression -
# concrete value, as well as 4 admitted arithmetic lemmas.
# Note that bv_equiv.zext/sext/trunc will have 'omitted' tests
# because sometimes generated expressions try to compare
# bitvectors with different bitwidths.
./run-proptest.sh

# Run random tests for the specification of LLVM assembly language.
# Set clang path to yours by modifying the script.
./run-irtest.sh

Theorems

• Specification, as well as proof, is in src/spec/.

1. Execution of bigstep with two different value semantics (SMT expr / concrete value) has some good relations.

def encode (ss:irstate_smt) (se:irstate_exec) (η:freevar.env) :=
    irstate_equiv (η⟦ss⟧) se

def bigstep_both:= ∀ ss se (p:program) oss' ose' η
    (HENC:encode ss se η)
    (HOSS': oss' = bigstep irsem_smt ss p)
    (HOSE': ose' = bigstep irsem_exec se p),
  none_or_some oss' ose' (λ ss' se', encode ss' se' η)
-- Its proof is at equiv.lean

2. We can generate initial state correctly.

def init_state_encode:= ∀ (freevars:list (string × ty)) (sg sg':std_gen) ise iss
    (HUNQ: list.unique $ freevars.map prod.fst)
    (HIE:(ise, sg') = create_init_state_exec freevars sg)
    (HIS:iss = create_init_state_smt freevars),
  ∃ η, encode iss ise η
-- Its proof is at initialstate.lean

3. If refinement checking function check_single_reg0 says it's true, refinement indeed holds.

def refines_single_reg_correct := ∀ (psrc ptgt:program)
    (root:string) (ss0:irstate_smt) sb
    (HSREF:some sb = check_single_reg0 irsem_smt psrc ptgt root ss0)
    (HEQ:∀ (η0:freevar.env) e, b_equiv (η0⟦sb⟧) e → e = tt),
  root_refines_smt psrc ptgt ss0 root
-- Its proof is at refinement.lean

Contributing

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This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.