Enable to type closure calls

Author: coord-e

src/analyze/basic_block.rs

@@ -84,16 +84,54 @@ impl<'tcx, 'ctx> Analyzer<'tcx, 'ctx> {
     ) -> Vec<chc::Clause> {
         let mut clauses = Vec::new();
 
-        if expected_args.is_empty() {
-            // elaboration: we need at least one predicate variable in parameter (see mir_function_ty_impl)
-            expected_args.push(rty::RefinedType::unrefined(rty::Type::unit()).vacuous());
-        }
         tracing::debug!(
             got = %got.display(),
             expected = %crate::pretty::FunctionType::new(&expected_args, &expected_ret).display(),
             "fn_sub_type"
         );
 
+        match got.abi {
+            rty::FunctionAbi::Rust => {
+                if expected_args.is_empty() {
+                    // elaboration: we need at least one predicate variable in parameter (see mir_function_ty_impl)
+                    expected_args.push(rty::RefinedType::unrefined(rty::Type::unit()).vacuous());
+                }
+            }
+            rty::FunctionAbi::RustCall => {
+                // &Closure, { v: (own i32, own bool) | v = (<0>, <false>) }
+                // =>
+                // &Closure, { v: i32 | (<v>, _) = (<0>, <false>) }, { v: bool | (_, <v>) = (<0>, <false>) }
+
+                let rty::RefinedType { ty, mut refinement } =
+                    expected_args.pop().expect("rust-call last arg");
+                let ty = ty.into_tuple().expect("rust-call last arg is tuple");
+                let mut replacement_tuple = Vec::new(); // will be (<v>, _) or (_, <v>)
+                for elem in &ty.elems {
+                    let existential = refinement.existentials.push(elem.ty.to_sort());
+                    replacement_tuple.push(chc::Term::var(rty::RefinedTypeVar::Existential(
+                        existential,
+                    )));
+                }
+
+                for (i, elem) in ty.elems.into_iter().enumerate() {
+                    let mut param_ty = elem.deref();
+                    param_ty
+                        .refinement
+                        .push_conj(refinement.clone().subst_value_var(|| {
+                            let mut value_elems = replacement_tuple.clone();
+                            value_elems[i] = chc::Term::var(rty::RefinedTypeVar::Value).boxed();
+                            chc::Term::tuple(value_elems)
+                        }));
+                    expected_args.push(param_ty);
+                }
+
+                tracing::info!(
+                    expected = %crate::pretty::FunctionType::new(&expected_args, &expected_ret).display(),
+                    "rust-call expanded",
+                );
+            }
+        }
+
         // TODO: check sty and length is equal
         let mut builder = self.env.build_clause();
         for (param_idx, param_rty) in got.params.iter_enumerated() {

src/chc.rs

@@ -616,6 +616,10 @@ impl<V> Term<V> {
         Term::Mut(Box::new(t1), Box::new(t2))
     }
 
+    pub fn boxed(self) -> Self {
+        Term::Box(Box::new(self))
+    }
+
     pub fn box_current(self) -> Self {
         Term::BoxCurrent(Box::new(self))
     }

src/rty.rs

@@ -1351,6 +1351,29 @@ impl<FV> RefinedType<FV> {
         RefinedType { ty, refinement }
     }
 
+    pub fn deref(self) -> Self {
+        let RefinedType {
+            ty,
+            refinement: outer_refinement,
+        } = self;
+        let inner_ty = ty.into_pointer().expect("invalid deref");
+        if inner_ty.is_mut() {
+            // losing info about proph
+            panic!("invalid deref");
+        }
+        let RefinedType {
+            ty: inner_ty,
+            refinement: mut inner_refinement,
+        } = *inner_ty.elem;
+        inner_refinement.push_conj(
+            outer_refinement.subst_value_var(|| chc::Term::var(RefinedTypeVar::Value).boxed()),
+        );
+        RefinedType {
+            ty: inner_ty,
+            refinement: inner_refinement,
+        }
+    }
+
     pub fn subst_var<F, W>(self, mut f: F) -> RefinedType<W>
     where
         F: FnMut(FV) -> chc::Term<W>,

tests/ui/fail/closure_mut.rs

@@ -0,0 +1,12 @@
+//@error-in-other-file: Unsat
+//@compile-flags: -C debug-assertions=off
+
+fn main() {
+    let mut x = 1;
+    let mut incr = |by: i32| {
+        x += by;
+    };
+    incr(5);
+    incr(5);
+    assert!(x == 10);
+}

tests/ui/pass/closure_mut.rs

@@ -0,0 +1,12 @@
+//@check-pass
+//@compile-flags: -C debug-assertions=off
+
+fn main() {
+    let mut x = 1;
+    let mut incr = |by: i32| {
+        x += by;
+    };
+    incr(5);
+    incr(5);
+    assert!(x == 11);
+}