Add a verified interpreter for HeapLang

e5f526c3 · Tej Chajed · Ralf Jung · d3e1e7ff · e5f526c3 · e5f526c3
Commit e5f526c3 authored Mar 18, 2021 by Tej Chajed Committed by Ralf Jung Mar 18, 2021
--- a/_CoqProject
+++ b/_CoqProject
@@ -142,6 +142,7 @@ iris/proofmode/modality_instances.v
 iris_heap_lang/locations.v
 iris_heap_lang/lang.v
 iris_heap_lang/class_instances.v
+iris_heap_lang/pretty.v
 iris_heap_lang/metatheory.v
 iris_heap_lang/tactics.v
 iris_heap_lang/primitive_laws.v
@@ -174,3 +175,5 @@ iris_deprecated/base_logic/auth.v
 iris_deprecated/base_logic/sts.v
 iris_deprecated/base_logic/viewshifts.v
 iris_deprecated/program_logic/hoare.v
+
+iris_staging/heap_lang/interpreter.v
--- a/coq-iris-staging.opam
+++ b/coq-iris-staging.opam
@@ -14,6 +14,7 @@ work is needed before they are ready for this.

 depends: [
  "coq-iris" {= version}
+  "coq-iris-heap-lang" {= version}
 ]

 build: ["./make-package" "iris_staging" "-j%{jobs}%"]

--- a/iris_heap_lang/locations.v
+++ b/iris_heap_lang/locations.v
@@ -2,15 +2,17 @@ From stdpp Require Import countable numbers gmap.
 From iris.prelude Require Export prelude.
 From iris.prelude Require Import options.

-Record loc := { loc_car : Z }.
+Record loc := Loc { loc_car : Z }.
+
+Add Printing Constructor loc.

 Global Instance loc_eq_decision : EqDecision loc.
-Proof. solve_decision. Qed.
+Proof. solve_decision. Defined.

 Global Instance loc_inhabited : Inhabited loc := populate {|loc_car := 0 |}.

 Global Instance loc_countable : Countable loc.
-Proof. by apply (inj_countable' loc_car (λ i, {| loc_car := i |})); intros []. Qed.
+Proof. by apply (inj_countable' loc_car Loc); intros []. Defined.

 Program Instance loc_infinite : Infinite loc :=
  inj_infinite (λ p, {| loc_car := p |}) (λ l, Some (loc_car l)) _.

--- a/iris_heap_lang/pretty.v
+++ b/iris_heap_lang/pretty.v
+From stdpp Require Export pretty.
+
+From iris.heap_lang Require Import lang.
+From iris.prelude Require Import options.
+
+(** * Pretty printing for HeapLang values *)
+
+Global Instance pretty_loc : Pretty loc :=
+  λ l, pretty l.(loc_car).
+
+Global Instance pretty_base_lit : Pretty base_lit :=
+  λ l, match l with
+       | LitInt z => pretty z
+       | LitBool b => if b then "true" else "false"
+       | LitUnit => "()"
+       | LitPoison => "<poison>"
+       | LitLoc l => "(loc " +:+ pretty l +:+ ")"
+       | LitProphecy i => "(prophecy " +:+ pretty i +:+ ")"
+       end.
+
+Global Instance pretty_binder : Pretty binder :=
+  λ b, match b with
+       | BNamed x => x
+       | BAnon => "<>"
+       end.
+
+(** Note that this instance does not print function bodies and is thus not
+injective (unlike most `pretty` instances). *)
+Global Instance pretty_val : Pretty val :=
+  fix go v :=
+    match v with
+    | LitV l => "#" +:+ pretty l
+    | RecV f x e =>
+      match f with
+      | BNamed f => "rec: " +:+ f +:+ " " +:+ pretty x +:+ " := <body>"
+      | BAnon => "λ: " +:+ pretty x +:+ ", <body>"
+      end
+    | PairV v1 v2 => "(" +:+ go v1 +:+ ", " +:+ go v2 +:+ ")"
+    | InjLV v => "inl (" +:+ go v +:+ ")"
+    | InjRV v => "inr (" +:+ go v +:+ ")"
+    end.
+
+Global Instance pretty_un_op : Pretty un_op :=
+  λ op, match op with
+        | NegOp => "~"
+        | MinusUnOp => "-"
+        end.
+
+Global Instance pretty_bin_op : Pretty bin_op :=
+  λ op, match op with
+        | PlusOp => "+"
+        | MinusOp => "-"
+        | MultOp => "*"
+        | QuotOp => "`quot`"
+        | RemOp => "`rem`"
+        | AndOp => "&"
+        | OrOp => "|"
+        | XorOp => "`xor`"
+        | ShiftLOp => "<<"
+        | ShiftROp => ">>"
+        | LeOp => "≤"
+        | LtOp => "<"
+        | EqOp => "="
+        | OffsetOp => "+ₗ"
+        end .
--- a/iris_staging/heap_lang/interpreter.v
+++ b/iris_staging/heap_lang/interpreter.v
--- a/tests/heap_lang_interpreter.ref
+++ b/tests/heap_lang_interpreter.ref
+"ex1"
+     : string
+     = inl #()
+     : val + Error
+"ex3"
+     : string
+     = inl #2
+     : val + Error
+"ex4"
+     : string
+     = inl #(Loc 2)
+     : val + Error
+"ex5"
+     : string
+     = inl #false
+     : val + Error
+"ex6"
+     : string
+     = inl #2
+     : val + Error
+"fail app non-function"
+     : string
+     = inr (Stuck "attempt to call non-function #2")
+     : val + Error
+"fail loc order"
+     : string
+     = inr
+         (Stuck
+            "bin-op failed: the only supported operation on locations is +ₗ #i, got < #(loc 2)")
+     : val + Error
+"fail compare pairs"
+     : string
+     = inr
+         (Stuck
+            "bin-op failed: one of (#0, #1) and (#0, #1) must be unboxed to compare: (#0, #1): pairs are large and considered boxed, must compare by field, (#0, #1): pairs are large and considered boxed, must compare by field")
+     : val + Error
+"fail free var"
+     : string
+     = inr (Stuck "free var: x")
+     : val + Error
+"fail out of fuel"
+     : string
+     = inl (rec: "foo" <> := "foo" #())%V
+     : val + Error
--- a/tests/heap_lang_interpreter.v
+++ b/tests/heap_lang_interpreter.v
+From iris.heap_lang Require Import notation.
+From iris.staging.heap_lang Require Import interpreter.
+
+Example test_1 :
+  exec 1000 ((λ: "x", "x" + #1) #2) = inl #3.
+Proof. reflexivity. Qed.
+
+Check "ex1".
+Eval vm_compute in
+    exec 1000 (let: "x" := ref #() in
+               let: "y" := ref #() in
+               !"y").
+
+Check "ex3".
+(** eval order *)
+Eval vm_compute in
+    exec 1000 (let: "x" := ref #1 in
+               let: "y" := ref #2 in
+               ("y" <- !"x",
+                (* this runs first, so the result is 2 *)
+                "x" <- !"y");;
+               !"x").
+
+(* print a location *)
+Check "ex4".
+Eval vm_compute in
+    exec 1000 (ref #();; ref #()).
+
+Check "ex5".
+Eval vm_compute in
+    exec 1000 (let: "x" := ref #() in
+               let: "y" := ref #() in
+               "x" = "y").
+
+(* a bad case where the interpreter runs a program which is actually stuck,
+because this program guesses an allocation that happens to be correct in the
+interpreter *)
+Check "ex6".
+Eval vm_compute in
+    exec 1000 (let: "x" := ref #1 in
+              #(LitLoc {|loc_car := 1|}) <- #2;;
+              !"x").
+
+(** * Failing executions *)
+
+Check "fail app non-function".
+Eval vm_compute in
+    exec 1000 (#2 #4).
+
+(* locations are not ordered *)
+Check "fail loc order".
+Eval vm_compute in
+    exec 1000 (let: "x" := ref #() in
+               let: "y" := ref #() in
+               "x" < "y").
+
+Check "fail compare pairs".
+Eval vm_compute in
+    exec 1000 ((#0, #1) = (#0, #1)).
+
+Check "fail free var".
+Eval vm_compute in exec 100 "x".
+
+Check "fail out of fuel".
+(** infinite loop *)
+Eval vm_compute in exec 100 (rec: "foo" <> := "foo" #()).