Library iris.proofmode.pviewshifts

From iris.proofmode Require Import coq_tactics spec_patterns.
From iris.proofmode Require Export tactics.
From iris.program_logic Require Export pviewshifts.
Import uPred.

Section pvs.
Context {Λ : language} {Σ : iFunctor}.
Implicit Types P Q : iProp Λ Σ.

Global Instance from_pure_pvs E P φ : FromPure P φ FromPure (|={E}=> P) φ.
Proof. intros ??. by rewrite -pvs_intro (from_pure P). Qed.
Global Instance from_assumption_pvs E p P Q :
  FromAssumption p P Q FromAssumption p P (|={E}=> Q)%I.
Proof. rewrite /FromAssumption=>->. apply pvs_intro. Qed.
Global Instance from_sep_pvs E P Q1 Q2 :
  FromSep P Q1 Q2 FromSep (|={E}=> P) (|={E}=> Q1) (|={E}=> Q2).
Proof. rewrite /FromSep=><-. apply pvs_sep. Qed.
Global Instance or_split_pvs E1 E2 P Q1 Q2 :
  FromOr P Q1 Q2 FromOr (|={E1,E2}=> P) (|={E1,E2}=> Q1) (|={E1,E2}=> Q2).
Proof. rewrite /FromOr=><-. apply or_elim; apply pvs_mono; auto with I. Qed.
Global Instance exists_split_pvs {A} E1 E2 P (Φ : A iProp Λ Σ) :
  FromExist P Φ FromExist (|={E1,E2}=> P) (λ a, |={E1,E2}=> Φ a)%I.
Proof.
  rewrite /FromExist=><-. apply exist_elima. by rewrite -(exist_intro a).
Qed.
Global Instance frame_pvs E1 E2 R P Q :
  Frame R P Q Frame R (|={E1,E2}=> P) (|={E1,E2}=> Q).
Proof. rewrite /Frame=><-. by rewrite pvs_frame_l. Qed.
Global Instance into_wand_pvs E1 E2 R P Q :
  IntoWand R P Q IntoWand R (|={E1,E2}=> P) (|={E1,E2}=> Q) | 100.
Proof. rewrite /IntoWand=>->. apply wand_intro_l. by rewrite pvs_wand_r. Qed.

Global Instance timeless_elim_pvs E1 E2 Q : TimelessElim (|={E1,E2}=> Q).
Proof.
  intros P ?. rewrite (pvs_timeless E1 P) pvs_frame_r.
  by rewrite wand_elim_r pvs_trans; last set_solver.
Qed.

Global Instance atimeless_elim_pvs E1 E2 Q : ATimelessElim (|={E1,E2}=> Q).
Proof.
  intros P ?. rewrite (pvs_timeless_affine E1 P) pvs_frame_r.
  by rewrite wand_elim_r pvs_trans; last set_solver.
Qed.

Class IsFSA {A} (P : iProp Λ Σ) (E : coPset)
    (fsa : FSA Λ Σ A) (fsaV : Prop) (Φ : A iProp Λ Σ) := {
  is_fsa : P ⊣⊢ fsa E Φ;
  is_fsa_is_fsa :> FrameShiftAssertion fsaV fsa;
}.
Global Arguments is_fsa {_} _ _ _ _ _ {_}.
Global Instance is_fsa_pvs E P :
  IsFSA (|={E}=> P)%I E pvs_fsa True (λ _, P).
Proof. split. done. apply _. Qed.
Global Instance is_fsa_fsa {A} (fsa : FSA Λ Σ A) E Φ :
  FrameShiftAssertion fsaV fsa IsFSA (fsa E Φ) E fsa fsaV Φ.
Proof. done. Qed.

Global Instance to_assert_pvs {A} P Q E (fsa : FSA Λ Σ A) fsaV Φ :
  IsFSA Q E fsa fsaV Φ IntoAssert P Q (|={E}=> P).
Proof.
  intros. by rewrite /IntoAssert pvs_frame_r wand_elim_r (is_fsa Q) fsa_pvs_fsa.
Qed.
Global Instance timeless_elim_fsa {A} Q E (fsa : FSA Λ Σ A) fsaV Φ :
  IsFSA Q E fsa fsaV Φ TimelessElim Q.
Proof.
  intros ? P ?. rewrite (is_fsa Q) -{2}fsa_pvs_fsa.
  by rewrite (pvs_timeless _ P) pvs_frame_r wand_elim_r.
Qed.
Global Instance atimeless_elim_fsa {A} Q E (fsa : FSA Λ Σ A) fsaV Φ :
  IsFSA Q E fsa fsaV Φ ATimelessElim Q.
Proof.
  intros ? P ?. rewrite (is_fsa Q) -{2}fsa_pvs_fsa.
  by rewrite (pvs_timeless_affine _ P) pvs_frame_r wand_elim_r.
Qed.

Lemma tac_pvs_intro Δ E1 E2 Q : E1 = E2 (Δ Q) Δ |={E1,E2}=> Q.
Proof. intros → →. apply pvs_intro. Qed.

Lemma tac_pvs_elim Δ Δ' E1 E2 E3 i p P' E1' E2' P Q :
  envs_lookup i Δ = Some (p, P') P' = (|={E1',E2'}=> P)%I
  (E1' = E1 E2' = E2 E2 E1 E3
   E2 = E2' E1 E1' E2' E1 E1' E1' E1 E2' E1' E3)
  envs_replace i p false (Esnoc Enil i P) Δ = Some Δ'
  (Δ' ={E2,E3}=> Q) Δ ={E1,E3}=> Q.
Proof.
  intros ? → HE ? HQ. rewrite envs_replace_sound //; simpl. destruct p.
  - rewrite relevant_elim right_id pvs_frame_r wand_elim_r HQ.
    destruct HE as [(?&?&?)|(?&?&?&?)]; subst; first (by apply pvs_trans).
    etrans; [eapply pvs_mask_frame'|apply pvs_trans]; auto; set_solver.
  - rewrite right_id pvs_frame_r wand_elim_r HQ.
    destruct HE as [(?&?&?)|(?&?&?&?)]; subst; first (by apply pvs_trans).
    etrans; [eapply pvs_mask_frame'|apply pvs_trans]; auto; set_solver.
Qed.

Lemma tac_pvs_elim' Δ Δ' E1 E2 E3 i p P' E1' E2' P Q :
  envs_lookup i Δ = Some (p, P') (P' (|={E1',E2'}=> P)%I)
  (E1' = E1 E2' = E2 E2 E1 E3
   E2 = E2' E1 E1' E2' E1 E1' E1' E1 E2' E1' E3)
  envs_replace i p false (Esnoc Enil i P) Δ = Some Δ'
  (Δ' ={E2,E3}=> Q) Δ ={E1,E3}=> Q.
Proof.
  intros ? HP' HE ? HQ. rewrite envs_replace_sound //; simpl. destruct p; rewrite HP'.
  - rewrite relevant_elim right_id pvs_frame_r wand_elim_r HQ.
    destruct HE as [(?&?&?)|(?&?&?&?)]; subst; first (by apply pvs_trans).
    etrans; [eapply pvs_mask_frame'|apply pvs_trans]; auto; set_solver.
  - rewrite right_id pvs_frame_r wand_elim_r HQ.
    destruct HE as [(?&?&?)|(?&?&?&?)]; subst; first (by apply pvs_trans).
    etrans; [eapply pvs_mask_frame'|apply pvs_trans]; auto; set_solver.
Qed.

Lemma tac_pvs_elim_fsa {A} (fsa : FSA Λ Σ A) fsaV Δ Δ' E i p P' P Q Φ :
  envs_lookup i Δ = Some (p, P') P' = (|={E}=> P)%I
  IsFSA Q E fsa fsaV Φ
  envs_replace i p false (Esnoc Enil i P) Δ = Some Δ'
  (Δ' fsa E Φ) Δ Q.
Proof.
  intros ? → ??. rewrite (is_fsa Q) -fsa_pvs_fsa.
  eapply tac_pvs_elim; set_solver.
Qed.

Class IsAFSA {A} (P : iProp Λ Σ) (E : coPset)
    (fsa : FSA Λ Σ A) (fsaV : Prop) (Φ : A iProp Λ Σ) := {
  is_afsa : P ⊣⊢ fsa E Φ;
  is_afsa_is_afsa :> AffineFrameShiftAssertion fsaV fsa;
}.
Global Arguments is_afsa {_} _ _ _ _ _ {_}.
Global Instance is_afsa_pvs E P :
  IsAFSA (|={E}=> P)%I E pvs_fsa True (λ _, P).
Proof. split. done. apply fsa_afsa, _. Qed.
Global Instance is_afsa_afsa {A} (fsa : FSA Λ Σ A) E Φ :
  AffineFrameShiftAssertion fsaV fsa IsAFSA (fsa E Φ) E fsa fsaV Φ.
Proof. done. Qed.

Class IntoPvs R E P := into_pvs : R (|={E}=> P).
Global Arguments into_pvs : clear implicits.
Global Instance into_pvs_pvs E P: IntoPvs (|={E}=> P)%I E P.
Proof. rewrite /IntoPvs. reflexivity. Qed.
Global Instance into_pvs_relevant R E P: IntoPvs R E P IntoPvs ( R) E P.
Proof. rewrite /IntoPvs⇒ →. apply relevant_elim. Qed.
Global Instance into_pvs_affine R E P : IntoPvs R E P IntoPvs ( R) E P.
Proof. rewrite /IntoPvs⇒ →. apply affine_elim. Qed.

Lemma tac_pvs_elim_afsa {A} (fsa : FSA Λ Σ A) fsaV Δ Δ' E i p P0 P Q Φ :
  envs_lookup i Δ = Some (p, P0)%I IntoPvs P0 E P IsAFSA Q E fsa fsaV Φ
  envs_replace i p false (Esnoc Enil i P) Δ = Some Δ'
  (Δ' fsa E Φ) Δ Q.
Proof.
  intros ???. rewrite (is_afsa Q) -afsa_pvs_afsa.
  eapply tac_pvs_elim'; eauto; set_solver.
Qed.

Global Instance timeless_elim_afsa {A} Q E (fsa : FSA Λ Σ A) fsaV Φ :
  IsAFSA Q E fsa fsaV Φ TimelessElim Q.
Proof.
  intros ? P ?. rewrite (is_afsa Q) -{2}afsa_pvs_afsa.
  by rewrite (pvs_timeless _ P) pvs_frame_r wand_elim_r.
Qed.

Global Instance atimeless_elim_afsa {A} Q E (fsa : FSA Λ Σ A) fsaV Φ :
  IsAFSA Q E fsa fsaV Φ ATimelessElim Q.
Proof.
  intros ? P ?. rewrite (is_afsa Q) -{2}afsa_pvs_afsa.
  by rewrite (pvs_timeless_affine _ P) pvs_frame_r wand_elim_r.
Qed.


Lemma tac_pvs_timeless Δ Δ' E1 E2 i P Q :
  envs_lookup i Δ = Some (false, P)%I TimelessP P
  envs_simple_replace i false (Esnoc Enil i P) Δ = Some Δ'
  (Δ' |={E1,E2}=> Q) Δ (|={E1,E2}=> Q).
Proof.
  intros ??? HQ. rewrite envs_simple_replace_sound //; simpl.
  rewrite (pvs_timeless E1 P) pvs_frame_r right_id wand_elim_r HQ.
    by rewrite pvs_trans; last set_solver.
Qed.

Lemma tac_pvs_timeless_affine Δ Δ' E1 E2 i P Q :
  envs_lookup i Δ = Some (false, P)%I ATimelessP P
  envs_simple_replace i false (Esnoc Enil i (P)) Δ = Some Δ'
  (Δ' |={E1,E2}=> Q) Δ (|={E1,E2}=> Q).
Proof.
  intros ??? HQ. rewrite envs_simple_replace_sound //; simpl.
  rewrite (pvs_timeless_affine E1 P) pvs_frame_r right_id wand_elim_r HQ.
    by rewrite pvs_trans; last set_solver.
Qed.


Lemma tac_pvs_timeless_fsa {A} (fsa : FSA Λ Σ A) fsaV Δ Δ' E i P Q Φ :
  IsAFSA Q E fsa fsaV Φ
  envs_lookup i Δ = Some (false, P)%I TimelessP P
  envs_simple_replace i false (Esnoc Enil i P) Δ = Some Δ'
  (Δ' fsa E Φ) Δ Q.
Proof.
  intros ????. rewrite (is_afsa Q) -afsa_pvs_afsa.
  eauto using tac_pvs_timeless.
Qed.

Lemma tac_pvs_timeless_fsa_affine {A} (fsa : FSA Λ Σ A) fsaV Δ Δ' E i P Q Φ :
  IsAFSA Q E fsa fsaV Φ
  envs_lookup i Δ = Some (false, P)%I ATimelessP P
  envs_simple_replace i false (Esnoc Enil i (P)) Δ = Some Δ'
  (Δ' fsa E Φ) Δ Q.
Proof.
  intros ????. rewrite (is_afsa Q) -afsa_pvs_afsa.
  eauto using tac_pvs_timeless_affine.
Qed.

Lemma tac_pvs_assert {A} (fsa : FSA Λ Σ A) fsaV Δ Δ1 Δ2 Δ2' E lr js j P Q Φ :
  IsAFSA Q E fsa fsaV Φ
  envs_split lr js Δ = Some (Δ1,Δ2)
  envs_app false (Esnoc Enil j P) Δ2 = Some Δ2'
  (Δ1 |={E}=> P) (Δ2' fsa E Φ) Δ Q.
Proof.
  intros ??? HP HQ. rewrite (is_afsa Q) -afsa_pvs_afsa -HQ envs_split_sound //.
  rewrite HP envs_app_sound //; simpl.
  by rewrite right_id pvs_frame_r wand_elim_r.
Qed.
End pvs.

Tactic Notation "iPvsIntro" := apply tac_pvs_intro; first try fast_done.

Tactic Notation "iPvsCore" constr(H) :=
  match goal with
  | |- _ |={_,_}=> _
    eapply tac_pvs_elim with _ _ H _ _ _ _ _;
      [env_cbv; reflexivity || fail "iPvs:" H "not found"
      |let P := match goal with |- ?P = _P end in
       reflexivity || fail "iPvs:" H ":" P "not a pvs with the right mask"
      |first
         [left; split_and!;
            [reflexivity|reflexivity|try (rewrite (idemp_L (∪)); reflexivity)]
         |right; split; first reflexivity]
      |env_cbv; reflexivity|]
  | |- ?Δ _
    let Δ' := fresh "Δ" in
    match type of Δ with
    | uPred ?T
      evar (Δ': coq_tactics.envs T);
        eapply tac_pvs_elim_afsa with _ _ Δ' _ H _ _ _ _;
        [env_cbv; reflexivity || fail "iPvs:" H "not found"
        |let P := match goal with |- IntoPvs ?P _ _P end in
         apply _ || fail "iPvs:" P "not a pvs"
        |let P := match goal with |- IsAFSA ?P _ _ _ _P end in
         apply _ || fail "iPvs:" P "not a pvs"
        |env_cbv; rewrite /Δ'; eauto | simpl; rewrite /Δ'; clear Δ']
    end
  end.

Tactic Notation "iPvs" open_constr(lem) :=
  iDestructCore lem as (fun HiPvsCore H; last iDestruct H as "?").
Tactic Notation "iPvs" open_constr(lem) "as" constr(pat) :=
  iDestructCore lem as (fun HiPvsCore H; last iDestruct H as pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1) ")"
    constr(pat) :=
  iDestructCore lem as (fun HiPvsCore H; last iDestruct H as ( x1 ) pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1)
    simple_intropattern(x2) ")" constr(pat) :=
  iDestructCore lem as (fun HiPvsCore H; last iDestruct H as ( x1 x2 ) pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1)
    simple_intropattern(x2) simple_intropattern(x3) ")" constr(pat) :=
  iDestructCore lem as (fun HiPvsCore H; last iDestruct H as ( x1 x2 x3 ) pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1)
    simple_intropattern(x2) simple_intropattern(x3) simple_intropattern(x4) ")"
    constr(pat) :=
  iDestructCore lem as (fun H
    iPvsCore H; last iDestruct H as ( x1 x2 x3 x4 ) pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1)
    simple_intropattern(x2) simple_intropattern(x3) simple_intropattern(x4)
    simple_intropattern(x5) ")" constr(pat) :=
  iDestructCore lem as (fun H
    iPvsCore H; last iDestruct H as ( x1 x2 x3 x4 x5 ) pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1)
    simple_intropattern(x2) simple_intropattern(x3) simple_intropattern(x4)
    simple_intropattern(x5) simple_intropattern(x6) ")" constr(pat) :=
  iDestructCore lem as (fun H
    iPvsCore H; last iDestruct H as ( x1 x2 x3 x4 x5 x6 ) pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1)
    simple_intropattern(x2) simple_intropattern(x3) simple_intropattern(x4)
    simple_intropattern(x5) simple_intropattern(x6) simple_intropattern(x7) ")"
    constr(pat) :=
  iDestructCore lem as (fun H
    iPvsCore H; last iDestruct H as ( x1 x2 x3 x4 x5 x6 x7 ) pat).
Tactic Notation "iPvs" open_constr(lem) "as" "(" simple_intropattern(x1)
    simple_intropattern(x2) simple_intropattern(x3) simple_intropattern(x4)
    simple_intropattern(x5) simple_intropattern(x6) simple_intropattern(x7)
    simple_intropattern(x8) ")" constr(pat) :=
  iDestructCore lem as (fun H
    iPvsCore H; last iDestruct H as ( x1 x2 x3 x4 x5 x6 x7 x8 ) pat).

Hint Extern 2 (of_envs _ _) ⇒
  match goal with |- _ (|={_}=> _)%IiPvsIntro end.