(** ** Relating stacks *)
Inductive match_stacks (F: meminj) (m m': mem):
list stackframe -> list stackframe -> block -> Prop :=
| match_stacks_nil: forall bound1 bound
(MG: match_globalenvs F bound1)
(BELOW: Ple bound1 bound),
match_stacks F m m' nil nil bound
| match_stacks_cons: forall res f sp pc rs stk f' sp' rs' stk' bound fenv ctx
(MS: match_stacks_inside F m m' stk stk' f' ctx sp' rs')
(COMPAT: fenv_compat prog fenv)
(FB: tr_funbody fenv f'.(fn_stacksize) ctx f f'.(fn_code))
(AG: agree_regs F ctx rs rs')
(SP: F sp = Some(sp', ctx.(dstk)))
(PRIV: range_private F m m' sp' (ctx.(dstk) + ctx.(mstk)) f'.(fn_stacksize))
(SSZ1: 0 <= f'.(fn_stacksize) < Ptrofs.max_unsigned)
(SSZ2: forall ofs, Mem.perm m' sp' ofs Max Nonempty -> 0 <= ofs <= f'.(fn_stacksize))
(RES: Ple res ctx.(mreg))
(BELOW: Plt sp' bound),
match_stacks F m m'
(Stackframe res f (Vptr sp Ptrofs.zero) pc rs :: stk)
(Stackframe (sreg ctx res) f' (Vptr sp' Ptrofs.zero) (spc ctx pc) rs' :: stk')
bound
| match_stacks_untailcall: forall stk res f' sp' rpc rs' stk' bound ctx
(MS: match_stacks_inside F m m' stk stk' f' ctx sp' rs')
(PRIV: range_private F m m' sp' ctx.(dstk) f'.(fn_stacksize))
(SSZ1: 0 <= f'.(fn_stacksize) < Ptrofs.max_unsigned)
(SSZ2: forall ofs, Mem.perm m' sp' ofs Max Nonempty -> 0 <= ofs <= f'.(fn_stacksize))
(RET: ctx.(retinfo) = Some (rpc, res))
(BELOW: Plt sp' bound),
match_stacks F m m'
stk
(Stackframe res f' (Vptr sp' Ptrofs.zero) rpc rs' :: stk')
bound
with match_stacks_inside (F: meminj) (m m': mem):
list stackframe -> list stackframe -> function -> context -> block -> regset -> Prop :=
| match_stacks_inside_base: forall stk stk' f' ctx sp' rs'
(MS: match_stacks F m m' stk stk' sp')
(RET: ctx.(retinfo) = None)
(DSTK: ctx.(dstk) = 0),
match_stacks_inside F m m' stk stk' f' ctx sp' rs'
| match_stacks_inside_inlined: forall res f sp pc rs stk stk' f' fenv ctx sp' rs' ctx'
(MS: match_stacks_inside F m m' stk stk' f' ctx' sp' rs')
(COMPAT: fenv_compat prog fenv)
(FB: tr_funbody fenv f'.(fn_stacksize) ctx' f f'.(fn_code))
(AG: agree_regs F ctx' rs rs')
(SP: F sp = Some(sp', ctx'.(dstk)))
(PAD: range_private F m m' sp' (ctx'.(dstk) + ctx'.(mstk)) ctx.(dstk))
(RES: Ple res ctx'.(mreg))
(RET: ctx.(retinfo) = Some (spc ctx' pc, sreg ctx' res))
(BELOW: context_below ctx' ctx)
(SBELOW: context_stack_call ctx' ctx),
match_stacks_inside F m m' (Stackframe res f (Vptr sp Ptrofs.zero) pc rs :: stk)
stk' f' ctx sp' rs'.
(** Properties of match_stacks *)
Section MATCH_STACKS.
Variable F: meminj.
Variables m m': mem.

(* Specifications: *)
Lemma match_stacks_globalenvs:
forall stk stk' bound,
match_stacks F m m' stk stk' bound -> exists b, match_globalenvs F b
with match_stacks_inside_globalenvs:
forall stk stk' f ctx sp rs',
match_stacks_inside F m m' stk stk' f ctx sp rs' -> exists b, match_globalenvs F b.
Lemma match_globalenvs_preserves_globals:
forall b, match_globalenvs F b -> meminj_preserves_globals ge F.
Lemma match_stacks_inside_globals:
forall stk stk' f ctx sp rs',
match_stacks_inside F m m' stk stk' f ctx sp rs' -> meminj_preserves_globals ge F.
Lemma match_stacks_bound:
forall stk stk' bound bound1,
match_stacks F m m' stk stk' bound ->
Ple bound bound1 ->
match_stacks F m m' stk stk' bound1.