move error into regular .v file

_CoqProject

@@ -166,6 +166,7 @@ iris_heap_lang/lib/increment.v
 iris_heap_lang/lib/diverge.v
 iris_heap_lang/lib/arith.v
 iris_heap_lang/lib/array.v
+iris_heap_lang/lib/one_shot.v
 
 iris_deprecated/base_logic/auth.v
 iris_deprecated/base_logic/sts.v

iris_heap_lang/lib/one_shot.v

+From iris.algebra Require Import excl agree csum.
+From iris.proofmode Require Import tactics.
+From iris.program_logic Require Export weakestpre.
+From iris.deprecated.program_logic Require Import hoare.
+From iris.heap_lang Require Export lang.
+From iris.heap_lang Require Import assert proofmode notation adequacy.
+From iris.heap_lang.lib Require Import par.
+Set Default Proof Using "Type".
+
+(** This is the introductory example from the "Iris from the Ground Up" journal
+paper. *)
+
+Unset Mangle Names.
+
+Definition one_shot_example : val := λ: <>,
+  let: "x" := ref NONE in (
+  (* tryset *) (λ: "n",
+    CAS "x" NONE (SOME "n")),
+  (* check  *) (λ: <>,
+    let: "y" := !"x" in λ: <>,
+    match: "y" with
+      NONE => #()
+    | SOME "n" =>
+       match: !"x" with
+         NONE => assert: #false
+       | SOME "m" => assert: "n" = "m"
+       end
+    end)).
+
+Definition one_shotR := csumR (exclR unitO) (agreeR ZO).
+Definition Pending : one_shotR := Cinl (Excl ()).
+Definition Shot (n : Z) : one_shotR := Cinr (to_agree n).
+
+Class one_shotG Σ := { one_shot_inG :> inG Σ one_shotR }.
+Definition one_shotΣ : gFunctors := #[GFunctor one_shotR].
+Global Instance subG_one_shotΣ {Σ} : subG one_shotΣ Σ → one_shotG Σ.
+Proof. solve_inG. Qed.
+
+Section proof.
+Local Set Default Proof Using "Type*".
+Context `{!heapG Σ, !one_shotG Σ}.
+
+Definition one_shot_inv (γ : gname) (l : loc) : iProp Σ :=
+  (l ↦ NONEV ∗ own γ Pending ∨ ∃ n : Z, l ↦ SOMEV #n ∗ own γ (Shot n))%I.
+
+Lemma wp_one_shot (Φ : val → iProp Σ) :
+  (∀ f1 f2 : val,
+    (∀ n : Z, □ WP f1 #n {{ w, ⌜w = #true⌝ ∨ ⌜w = #false⌝ }}) ∗
+    □ WP f2 #() {{ g, □ WP g #() {{ _, True }} }} -∗ Φ (f1,f2)%V)
+  ⊢ WP one_shot_example #() {{ Φ }}.
+Proof.
+  iIntros "Hf /=". pose proof (nroot .@ "N") as N.
+  wp_lam. wp_alloc l as "Hl".
+  iMod (own_alloc Pending) as (γ) "Hγ"; first done.
+  iMod (inv_alloc N _ (one_shot_inv γ l) with "[Hl Hγ]") as "#HN".
+  { iNext. iLeft. by iSplitL "Hl". }
+  wp_pures. iModIntro. iApply "Hf"; iSplit.
+  - iIntros (n) "!>". wp_lam. wp_pures. wp_bind (CmpXchg _ _ _).
+    iInv N as ">[[Hl Hγ]|H]"; last iDestruct "H" as (m) "[Hl Hγ]".
+    + iMod (own_update with "Hγ") as "Hγ".
+      { by apply cmra_update_exclusive with (y:=Shot n). }
+      wp_cmpxchg_suc. iModIntro. iSplitL; last (wp_pures; by eauto).
+      iNext; iRight; iExists n; by iFrame.
+    + wp_cmpxchg_fail. iModIntro. iSplitL; last (wp_pures; by eauto).
+      rewrite /one_shot_inv; eauto 10.
+  - iIntros "!> /=". wp_lam. wp_bind (! _)%E.
+    iInv N as ">Hγ".
+    iAssert (∃ v, l ↦ v ∗ ((⌜v = NONEV⌝ ∗ own γ Pending) ∨
+       ∃ n : Z, ⌜v = SOMEV #n⌝ ∗ own γ (Shot n)))%I with "[Hγ]" as "Hv".
+    { iDestruct "Hγ" as "[[Hl Hγ]|Hl]"; last iDestruct "Hl" as (m) "[Hl Hγ]".
+      + iExists NONEV. iFrame. eauto.
+      + iExists (SOMEV #m). iFrame. eauto. }
+    iDestruct "Hv" as (v) "[Hl Hv]". wp_load.
+    iAssert (one_shot_inv γ l ∗ (⌜v = NONEV⌝ ∨ ∃ n : Z,
+      ⌜v = SOMEV #n⌝ ∗ own γ (Shot n)))%I with "[Hl Hv]" as "[Hinv #Hv]".
+    { iDestruct "Hv" as "[[% ?]|Hv]"; last iDestruct "Hv" as (m) "[% ?]"; subst.
+      + iSplit. iLeft; by iSplitL "Hl". eauto.
+      + iSplit. iRight; iExists m; by iSplitL "Hl". eauto. }
+    iSplitL "Hinv"; first by eauto.
+    iModIntro. wp_pures. iIntros "!> !>". wp_lam.
+    iDestruct "Hv" as "[%|Hv]"; last iDestruct "Hv" as (m) "[% Hγ']";
+      subst; wp_match; [done|].
+    wp_bind (! _)%E.
+    iInv N as "[[Hl >Hγ]|H]"; last iDestruct "H" as (m') "[Hl Hγ]".
+    { by iDestruct (own_valid_2 with "Hγ Hγ'") as %?. }
+    wp_load.
+    iDestruct (own_valid_2 with "Hγ Hγ'") as %?%to_agree_op_inv_L; subst.
+    iModIntro. iSplitL "Hl".
+    { iNext; iRight; by eauto. }
+    wp_smart_apply wp_assert. wp_pures. by case_bool_decide.
+Qed.
+
+Lemma ht_one_shot (Φ : val → iProp Σ) :
+  ⊢ {{ True }} one_shot_example #()
+    {{ ff,
+      (∀ n : Z, {{ True }} Fst ff #n {{ w, ⌜w = #true⌝ ∨ ⌜w = #false⌝ }}) ∗
+      {{ True }} Snd ff #() {{ g, {{ True }} g #() {{ _, True }} }}
+    }}.
+Proof.
+  iIntros "!> _". iApply wp_one_shot. iIntros (f1 f2) "[#Hf1 #Hf2]"; iSplit.
+  - iIntros (n) "!> _". wp_smart_apply "Hf1".
+  - iIntros "!> _". wp_smart_apply (wp_wand with "Hf2"). by iIntros (v) "#? !> _".
+Qed.
+End proof.
+
+(* Have a client with a closed proof. *)
+Definition client : expr :=
+  let: "ff" := one_shot_example #() in
+  (Fst "ff" #5 ||| let: "check" := Snd "ff" #() in "check" #()).
+
+Section client.
+  Context `{!heapG Σ, !one_shotG Σ, !spawnG Σ}.
+
+  Lemma client_safe : ⊢ WP client {{ _, True }}.
+  Proof using Type*.
+    rewrite /client. wp_apply wp_one_shot. iIntros (f1 f2) "[#Hf1 #Hf2]".
+    wp_let. wp_smart_apply wp_par.
+    - wp_smart_apply "Hf1".
+    - wp_proj. wp_bind (f2 _)%E. iApply wp_wand; first by iExact "Hf2".
+      iIntros (check) "Hcheck". wp_pures. iApply "Hcheck".
+    - auto.
+  Qed.
+End client.
+
+(** Put together all library functors. *)
+Definition clientΣ : gFunctors := #[ heapΣ; one_shotΣ; spawnΣ ].
+(** This lemma implicitly shows that these functors are enough to meet
+all library assumptions. *)
+Lemma client_adequate σ : adequate NotStuck client σ (λ _ _, True).
+Proof. apply (heap_adequacy clientΣ)=> ?. iIntros "_". iApply client_safe. Qed.
+
+(* Since we check the output of the test files, this means
+our test suite will fail if we ever accidentally add an axiom
+to anything used by this proof. *)
+Print Assumptions client_adequate.