Analyze the impl body a trait-dispatched call resolves to

src/analyze/basic_block.rs

@@ -920,12 +920,25 @@ impl<'tcx, 'ctx> Analyzer<'tcx, 'ctx> {
  }
  }
 
+ /// Analyzes the body of the implementation a call dispatches to.
+ ///
+ /// A call typed by a trait method's spec never asks for the implementing method's type, and
+ /// an implementation with generic parameters is analyzed only when its type is asked for.
+ fn analyze_resolved_impl_body(&mut self, def_id: DefId, args: mir_ty::GenericArgsRef<'tcx>) {
+ let (impl_def_id, impl_args) = self.resolve_fn_def(def_id, args);
+ if impl_def_id == def_id {
+ return;
+ }
+ let _ = self.ctx.def_ty_with_args(impl_def_id, impl_args);
+ }
+
  fn fn_def_ty(
  &mut self,
  def_id: DefId,
  args: mir_ty::GenericArgsRef<'tcx>,
  ) -> rty::Type<rty::Closed> {
  if let Some(def_ty) = self.ctx.def_ty_with_args(def_id, args) {
+ self.analyze_resolved_impl_body(def_id, args);
  return def_ty.ty;
  }
 

src/analyze/local_def.rs

@@ -45,6 +45,7 @@ pub struct Analyzer<'tcx, 'ctx> {
  local_def_id: LocalDefId,
 
  body: Body<'tcx>,
+ /// the instantiation of the def's generic parameters being analyzed, also used
  /// to substitute HIR types during translation in [`crate::analyze::annot_fn`]
  generic_args: mir_ty::GenericArgsRef<'tcx>,
  drop_points: HashMap<BasicBlock, analyze::basic_block::DropPoints>,
@@ -198,7 +199,11 @@ impl<'tcx, 'ctx> Analyzer<'tcx, 'ctx> {
  return None;
  }
 
- let trait_ref = self.tcx.impl_trait_ref(impl_did)?.instantiate_identity();
+ // an associated method's generic arguments start with those of its impl
+ let trait_ref = self
+ .tcx
+ .impl_trait_ref(impl_did)?
+ .instantiate(self.tcx, self.generic_args);
  let trait_item_did = self
  .tcx
  .associated_item(self.local_def_id.to_def_id())
@@ -1115,7 +1120,7 @@ impl<'tcx, 'ctx> Analyzer<'tcx, 'ctx> {
  let body = tcx.optimized_mir(local_def_id.to_def_id()).clone();
  let drop_points = Default::default();
  let type_builder = TypeBuilder::new(tcx, ctx.def_ids(), local_def_id.to_def_id());
- let generic_args = tcx.mk_args(&[]);
+ let generic_args = mir_ty::GenericArgs::identity_for_item(tcx, local_def_id);
  Self {
  ctx,
  tcx,

tests/ui/fail/trait_generic_impl.rs

@@ -0,0 +1,29 @@
+//@error-in-other-file: Unsat
+//@compile-flags: -C debug-assertions=off
+
+#[thrust_macros::context]
+trait Tr {
+ #[thrust_macros::requires(true)]
+ #[thrust_macros::ensures(result > 0)]
+ fn m(&self) -> i32;
+}
+
+struct W<T>(T);
+
+impl<T> thrust_models::Model for W<T>
+where
+ T: thrust_models::Model,
+{
+ type Ty = Self;
+}
+
+impl<T> Tr for W<T> {
+ fn m(&self) -> i32 {
+ -1
+ }
+}
+
+fn main() {
+ let w = W(0i32);
+ assert!(w.m() > 0);
+}

tests/ui/pass/trait_generic_impl.rs

@@ -0,0 +1,29 @@
+//@check-pass
+//@compile-flags: -C debug-assertions=off
+
+#[thrust_macros::context]
+trait Tr {
+ #[thrust_macros::requires(true)]
+ #[thrust_macros::ensures(result > 0)]
+ fn m(&self) -> i32;
+}
+
+struct W<T>(T);
+
+impl<T> thrust_models::Model for W<T>
+where
+ T: thrust_models::Model,
+{
+ type Ty = Self;
+}
+
+impl<T> Tr for W<T> {
+ fn m(&self) -> i32 {
+ 1
+ }
+}
+
+fn main() {
+ let w = W(0i32);
+ assert!(w.m() > 0);
+}