Theory LBVJVM

theory LBVJVM
imports Typing_Framework_JVM
(*  Title:      HOL/MicroJava/BV/LBVJVM.thy
Author: Tobias Nipkow, Gerwin Klein
Copyright 2000 TUM
*)


header {* \isaheader{LBV for the JVM}\label{sec:JVM} *}

theory LBVJVM
imports Typing_Framework_JVM
begin

type_synonym prog_cert = "cname => sig => JVMType.state list"

definition check_cert :: "jvm_prog => nat => nat => nat => JVMType.state list => bool" where
"check_cert G mxs mxr n cert ≡ check_types G mxs mxr cert ∧ length cert = n+1 ∧
(∀i<n. cert!i ≠ Err) ∧ cert!n = OK None"


definition lbvjvm :: "jvm_prog => nat => nat => ty => exception_table =>
JVMType.state list => instr list => JVMType.state => JVMType.state"
where
"lbvjvm G maxs maxr rT et cert bs ≡
wtl_inst_list bs cert (JVMType.sup G maxs maxr) (JVMType.le G maxs maxr) Err (OK None) (exec G maxs rT et bs) 0"


definition wt_lbv :: "jvm_prog => cname => ty list => ty => nat => nat =>
exception_table => JVMType.state list => instr list => bool"
where
"wt_lbv G C pTs rT mxs mxl et cert ins ≡
check_bounded ins et ∧
check_cert G mxs (1+size pTs+mxl) (length ins) cert ∧
0 < size ins ∧
(let start = Some ([],(OK (Class C))#((map OK pTs))@(replicate mxl Err));
result = lbvjvm G mxs (1+size pTs+mxl) rT et cert ins (OK start)
in result ≠ Err)"


definition wt_jvm_prog_lbv :: "jvm_prog => prog_cert => bool" where
"wt_jvm_prog_lbv G cert ≡
wf_prog (λG C (sig,rT,(maxs,maxl,b,et)). wt_lbv G C (snd sig) rT maxs maxl et (cert C sig) b) G"


definition mk_cert :: "jvm_prog => nat => ty => exception_table => instr list
=> method_type => JVMType.state list"
where
"mk_cert G maxs rT et bs phi ≡ make_cert (exec G maxs rT et bs) (map OK phi) (OK None)"

definition prg_cert :: "jvm_prog => prog_type => prog_cert" where
"prg_cert G phi C sig ≡ let (C,rT,(maxs,maxl,ins,et)) = the (method (G,C) sig) in
mk_cert G maxs rT et ins (phi C sig)"



lemma wt_method_def2:
fixes pTs and mxl and G and mxs and rT and et and bs and phi
defines [simp]: "mxr ≡ 1 + length pTs + mxl"
defines [simp]: "r ≡ sup_state_opt G"
defines [simp]: "app0 ≡ λpc. app (bs!pc) G mxs rT pc et"
defines [simp]: "step0 ≡ λpc. eff (bs!pc) G pc et"

shows
"wt_method G C pTs rT mxs mxl bs et phi =
(bs ≠ [] ∧
length phi = length bs ∧
check_bounded bs et ∧
check_types G mxs mxr (map OK phi) ∧
wt_start G C pTs mxl phi ∧
wt_app_eff r app0 step0 phi)"

by (auto simp add: wt_method_def wt_app_eff_def wt_instr_def lesub_def
dest: check_bounded_is_bounded boundedD)


lemma check_certD:
"check_cert G mxs mxr n cert ==> cert_ok cert n Err (OK None) (states G mxs mxr)"
apply (unfold cert_ok_def check_cert_def check_types_def)
apply (auto simp add: list_all_iff)
done


lemma wt_lbv_wt_step:
assumes wf: "wf_prog wf_mb G"
assumes lbv: "wt_lbv G C pTs rT mxs mxl et cert ins"
assumes C: "is_class G C"
assumes pTs: "set pTs ⊆ types G"

defines [simp]: "mxr ≡ 1+length pTs+mxl"

shows "∃ts ∈ list (size ins) (states G mxs mxr).
wt_step (JVMType.le G mxs mxr) Err (exec G mxs rT et ins) ts
∧ OK (Some ([],(OK (Class C))#((map OK pTs))@(replicate mxl Err))) <=_(JVMType.le G mxs mxr) ts!0"

proof -
let ?step = "exec G mxs rT et ins"
let ?r = "JVMType.le G mxs mxr"
let ?f = "JVMType.sup G mxs mxr"
let ?A = "states G mxs mxr"

have "semilat (JVMType.sl G mxs mxr)"
by (rule semilat_JVM_slI, rule wf_prog_ws_prog, rule wf)
hence "semilat (?A, ?r, ?f)" by (unfold sl_triple_conv)
moreover
have "top ?r Err" by (simp add: JVM_le_unfold)
moreover
have "Err ∈ ?A" by (simp add: JVM_states_unfold)
moreover
have "bottom ?r (OK None)"
by (simp add: JVM_le_unfold bottom_def)
moreover
have "OK None ∈ ?A" by (simp add: JVM_states_unfold)
moreover
from lbv
have "bounded ?step (length ins)"
by (clarsimp simp add: wt_lbv_def exec_def)
(intro bounded_lift check_bounded_is_bounded)
moreover
from lbv
have "cert_ok cert (length ins) Err (OK None) ?A"
by (unfold wt_lbv_def) (auto dest: check_certD)
moreover
from wf have "pres_type ?step (length ins) ?A" by (rule exec_pres_type)
moreover
let ?start = "OK (Some ([],(OK (Class C))#(map OK pTs)@(replicate mxl Err)))"
from lbv
have "wtl_inst_list ins cert ?f ?r Err (OK None) ?step 0 ?start ≠ Err"
by (simp add: wt_lbv_def lbvjvm_def)
moreover
from C pTs have "?start ∈ ?A"
by (unfold JVM_states_unfold) (auto intro: list_appendI, force)
moreover
from lbv have "0 < length ins" by (simp add: wt_lbv_def)
ultimately
show ?thesis by (rule lbvs.wtl_sound_strong [OF lbvs.intro, OF lbv.intro lbvs_axioms.intro, OF Semilat.intro lbv_axioms.intro])
qed

lemma wt_lbv_wt_method:
assumes wf: "wf_prog wf_mb G"
assumes lbv: "wt_lbv G C pTs rT mxs mxl et cert ins"
assumes C: "is_class G C"
assumes pTs: "set pTs ⊆ types G"

shows "∃phi. wt_method G C pTs rT mxs mxl ins et phi"
proof -
let ?mxr = "1 + length pTs + mxl"
let ?step = "exec G mxs rT et ins"
let ?r = "JVMType.le G mxs ?mxr"
let ?f = "JVMType.sup G mxs ?mxr"
let ?A = "states G mxs ?mxr"
let ?start = "OK (Some ([],(OK (Class C))#(map OK pTs)@(replicate mxl Err)))"

from lbv have l: "ins ≠ []" by (simp add: wt_lbv_def)
moreover
from wf lbv C pTs
obtain phi where
list: "phi ∈ list (length ins) ?A" and
step: "wt_step ?r Err ?step phi" and
start: "?start <=_?r phi!0"
by (blast dest: wt_lbv_wt_step)
from list have [simp]: "length phi = length ins" by simp
have "length (map ok_val phi) = length ins" by simp
moreover
from l have 0: "0 < length phi" by simp
with step obtain phi0 where "phi!0 = OK phi0"
by (unfold wt_step_def) blast
with start 0
have "wt_start G C pTs mxl (map ok_val phi)"
by (simp add: wt_start_def JVM_le_Err_conv lesub_def)
moreover
from lbv have chk_bounded: "check_bounded ins et"
by (simp add: wt_lbv_def)
moreover {
from list
have "check_types G mxs ?mxr phi"
by (simp add: check_types_def)
also from step
have [symmetric]: "map OK (map ok_val phi) = phi"
by (auto intro!: nth_equalityI simp add: wt_step_def)
finally have "check_types G mxs ?mxr (map OK (map ok_val phi))" .
}
moreover {
let ?app = "λpc. app (ins!pc) G mxs rT pc et"
let ?eff = "λpc. eff (ins!pc) G pc et"

from chk_bounded
have "bounded (err_step (length ins) ?app ?eff) (length ins)"
by (blast dest: check_bounded_is_bounded boundedD intro: bounded_err_stepI)
moreover
from step
have "wt_err_step (sup_state_opt G) ?step phi"
by (simp add: wt_err_step_def JVM_le_Err_conv)
ultimately
have "wt_app_eff (sup_state_opt G) ?app ?eff (map ok_val phi)"
by (auto intro: wt_err_imp_wt_app_eff simp add: exec_def)
}
ultimately
have "wt_method G C pTs rT mxs mxl ins et (map ok_val phi)"
by - (rule wt_method_def2 [THEN iffD2], simp)
thus ?thesis ..
qed


lemma wt_method_wt_lbv:
assumes wf: "wf_prog wf_mb G"
assumes wt: "wt_method G C pTs rT mxs mxl ins et phi"
assumes C: "is_class G C"
assumes pTs: "set pTs ⊆ types G"

defines [simp]: "cert ≡ mk_cert G mxs rT et ins phi"

shows "wt_lbv G C pTs rT mxs mxl et cert ins"
proof -
let ?mxr = "1 + length pTs + mxl"
let ?step = "exec G mxs rT et ins"
let ?app = "λpc. app (ins!pc) G mxs rT pc et"
let ?eff = "λpc. eff (ins!pc) G pc et"
let ?r = "JVMType.le G mxs ?mxr"
let ?f = "JVMType.sup G mxs ?mxr"
let ?A = "states G mxs ?mxr"
let ?phi = "map OK phi"
let ?cert = "make_cert ?step ?phi (OK None)"

from wt have
0: "0 < length ins" and
length: "length ins = length ?phi" and
ck_bounded: "check_bounded ins et" and
ck_types: "check_types G mxs ?mxr ?phi" and
wt_start: "wt_start G C pTs mxl phi" and
app_eff: "wt_app_eff (sup_state_opt G) ?app ?eff phi"
by (simp_all add: wt_method_def2)

have "semilat (JVMType.sl G mxs ?mxr)"
by (rule semilat_JVM_slI) (rule wf_prog_ws_prog [OF wf])
hence "semilat (?A, ?r, ?f)" by (unfold sl_triple_conv)
moreover
have "top ?r Err" by (simp add: JVM_le_unfold)
moreover
have "Err ∈ ?A" by (simp add: JVM_states_unfold)
moreover
have "bottom ?r (OK None)"
by (simp add: JVM_le_unfold bottom_def)
moreover
have "OK None ∈ ?A" by (simp add: JVM_states_unfold)
moreover
from ck_bounded
have bounded: "bounded ?step (length ins)"
by (clarsimp simp add: exec_def)
(intro bounded_lift check_bounded_is_bounded)
with wf
have "mono ?r ?step (length ins) ?A"
by (rule wf_prog_ws_prog [THEN exec_mono])
hence "mono ?r ?step (length ?phi) ?A" by (simp add: length)
moreover
from wf have "pres_type ?step (length ins) ?A" by (rule exec_pres_type)
hence "pres_type ?step (length ?phi) ?A" by (simp add: length)
moreover
from ck_types
have "set ?phi ⊆ ?A" by (simp add: check_types_def)
hence "∀pc. pc < length ?phi --> ?phi!pc ∈ ?A ∧ ?phi!pc ≠ Err" by auto
moreover
from bounded
have "bounded (exec G mxs rT et ins) (length ?phi)" by (simp add: length)
moreover
have "OK None ≠ Err" by simp
moreover
from bounded length app_eff
have "wt_err_step (sup_state_opt G) ?step ?phi"
by (auto intro: wt_app_eff_imp_wt_err simp add: exec_def)
hence "wt_step ?r Err ?step ?phi"
by (simp add: wt_err_step_def JVM_le_Err_conv)
moreover
let ?start = "OK (Some ([],(OK (Class C))#(map OK pTs)@(replicate mxl Err)))"
from 0 length have "0 < length phi" by auto
hence "?phi!0 = OK (phi!0)" by simp
with wt_start have "?start <=_?r ?phi!0"
by (clarsimp simp add: wt_start_def lesub_def JVM_le_Err_conv)
moreover
from C pTs have "?start ∈ ?A"
by (unfold JVM_states_unfold) (auto intro: list_appendI, force)
moreover
have "?start ≠ Err" by simp
moreover
note length
ultimately
have "wtl_inst_list ins ?cert ?f ?r Err (OK None) ?step 0 ?start ≠ Err"
by (rule lbvc.wtl_complete [OF lbvc.intro, OF lbv.intro lbvc_axioms.intro, OF Semilat.intro lbv_axioms.intro])
moreover
from 0 length have "phi ≠ []" by auto
moreover
from ck_types
have "check_types G mxs ?mxr ?cert"
by (auto simp add: make_cert_def check_types_def JVM_states_unfold)
moreover
note ck_bounded 0 length
ultimately
show ?thesis
by (simp add: wt_lbv_def lbvjvm_def mk_cert_def
check_cert_def make_cert_def nth_append)
qed



theorem jvm_lbv_correct:
"wt_jvm_prog_lbv G Cert ==> ∃Phi. wt_jvm_prog G Phi"
proof -
let ?Phi = "λC sig. let (C,rT,(maxs,maxl,ins,et)) = the (method (G,C) sig) in
SOME phi. wt_method G C (snd sig) rT maxs maxl ins et phi"


assume "wt_jvm_prog_lbv G Cert"
hence "wt_jvm_prog G ?Phi"
apply (unfold wt_jvm_prog_def wt_jvm_prog_lbv_def)
apply (erule jvm_prog_lift)
apply (auto dest: wt_lbv_wt_method intro: someI)
done
thus ?thesis by blast
qed

theorem jvm_lbv_complete:
"wt_jvm_prog G Phi ==> wt_jvm_prog_lbv G (prg_cert G Phi)"
apply (unfold wt_jvm_prog_def wt_jvm_prog_lbv_def)
apply (erule jvm_prog_lift)
apply (auto simp add: prg_cert_def intro: wt_method_wt_lbv)
done

end