[WIP] Semantics of immutable arguments

crates/flowistry/src/pdg/construct.rs

@@ -687,10 +687,11 @@ impl<'tcx> GraphConstructor<'tcx> {
     };
     // An attempt at getting immutable arguments to connect
     let parentable_srcs = if self.params.false_call_edges {
+      let dummy_state = PartialGraph::default();
+      let constructor_ref = &child_constructor;
       Either::Right(child_constructor.body.args_iter()
           .map(|local| Place::from(local))
-          .flat_map(|place| child_constructor.place_info.children(place).into_iter().chain([place]))
-          .map(|place| DepNode::new(place, child_constructor.make_call_string(RichLocation::Start), self.tcx, child_constructor.body.as_ref())))
+          .flat_map(move |place| constructor_ref.find_data_inputs(&dummy_state, place)))
     } else {
       Either::Left(child_graph
           .edges
@@ -864,23 +865,24 @@ impl<'tcx> GraphConstructor<'tcx> {
     let mut domains = IndexVec::from_elem_n(empty.clone(), bb_graph.len());
 
     if self.params.false_call_edges {
-      let start_domain = &mut domains[0_usize.into()];
-      // TODO, actually should traverse all of the types fields
+      let start_domain = &mut domains[0_u32.into()];
       for arg in self.body.args_iter() {
         let place = Place::from(arg);
-        start_domain.last_mutation
-            .entry(place)
-            .or_default()
-            .insert(RichLocation::Start);
-        for child in self.place_info.children(place).iter().copied().chain(Some(place)) {
-          let ty = child.ty(self.body.as_ref(), self.tcx);
-          if !ty.ty.is_mutable_ptr() {
-            continue;
-          }
-          let target = child.project_deeper(&[PlaceElem::Deref], self.tcx);
-          let initial = start_domain.last_mutation.entry(target).or_default();
-          initial.insert(RichLocation::Start);
+        for mutation in self.find_data_inputs(start_domain, place) {
+          start_domain.last_mutation
+              .entry(mutation.place)
+              .or_default()
+              .insert(RichLocation::Start);
         }
+        // for child in self.place_info.children(place).iter().copied() {
+        //   let ty = child.ty(self.body.as_ref(), self.tcx);
+        //   if !ty.ty.is_mutable_ptr() {
+        //     continue;
+        //   }
+        //   let target = child.project_deeper(&[PlaceElem::Deref], self.tcx);
+        //   let initial = start_domain.last_mutation.entry(target).or_default();
+        //   initial.insert(RichLocation::Start);
+        // }
       }
     }
 
@@ -910,7 +912,7 @@ impl<'tcx> GraphConstructor<'tcx> {
       for block in all_returns {
         let return_state = &domains[block];
         for (place, locations) in &return_state.last_mutation {
-          if place.local == RETURN_PLACE || place.is_arg(&self.body) {
+          if place.local == RETURN_PLACE || self.is_ptr_argument_mutation(*place) {
             for location in locations {
               let src = self.make_dep_node(*place, *location);
               let dst = self.make_dep_node(*place, RichLocation::End);
@@ -926,6 +928,13 @@ impl<'tcx> GraphConstructor<'tcx> {
     final_state
   }
 
+  fn is_ptr_argument_mutation(&self, place: Place<'tcx>) -> bool {
+    place.is_arg(&self.body)
+    //     && place.iter_projections().any(|(place_ref, projection)|
+    //       projection == PlaceElem::Deref && place_ref.ty(self.body.as_ref(), self.tcx).ty.is_mutable_ptr()
+    // )
+  }
+
   fn domain_to_petgraph(self, domain: PartialGraph<'tcx>) -> DepGraph<'tcx> {
     let mut graph: DiGraph<DepNode<'tcx>, DepEdge> = DiGraph::new();
     let mut nodes = FxHashMap::default();

crates/flowistry/tests/pdg.rs

@@ -505,6 +505,44 @@ fn main() {
   })
 }
 
+#[test]
+fn test_fields_passing_through() {
+
+  let input = r#"
+use std::num::Wrapping;
+fn pass(x2: &Wrapping<u32>) {
+  println!("{}", x2);
+}
+
+fn main() {
+  let ref mut i = Wrapping(0);
+  let y = 10;
+  i.0 += y;
+  pass(i);
+}
+"#;
+  let _ = env_logger::try_init();
+  flowistry::test_utils::compile(input, move |tcx| {
+    let def_id = get_main(tcx);
+    let params = PdgParams::new(tcx, def_id);
+
+    let with_edges = flowistry::pdg::compute_pdg(params.with_false_call_edges());
+
+    with_edges.generate_graphviz(
+      "graph.pdf"
+    ).unwrap();
+
+
+    assert!(connects(
+      tcx,
+      &with_edges,
+      "y",
+      "*x2",
+      None
+    ));
+  })
+}
+
 #[test]
 fn false_call_edges() {
   let input = r#"
@@ -531,6 +569,10 @@ fn main() {
     // ));
 
     let with_edges = flowistry::pdg::compute_pdg(params.with_false_call_edges());
+
+    with_edges.generate_graphviz(
+      "graph.pdf"
+    ).unwrap();
     assert!(connects(
       tcx,
       &with_edges,
@@ -560,6 +602,7 @@ fn get_user_data() -> UserData {
     };
 }
 fn send_user_data(user_data: &UserData) {}
+fn send2(user_data2: &UserData) {}
 fn modify_vec(v: &mut [i64]) {}
 fn main() {
     let ref mut p = get_user_data();
@@ -595,5 +638,12 @@ fn main() {
       "user_data",
       None,
     ));
+    assert!(!connects(
+      tcx,
+      with_edges,
+      "user_data",
+      "user_data2",
+      None,
+    ));
   });
 }