Merge #920

920: Support deref_mut lang item during method resolution r=philberty a=philberty

This adds in the lookups for the DEREF_MUT lang item for operator overloading
this needs more testing to ensure the behaviour is correct and is the same as
rustc.

Fixes #890


Co-authored-by: Philip Herron <philip.herron@embecosm.com>

1 files changed, 21 insertions, 18 deletions

diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc
index a592e35..65f159e 100644
--- a/gcc/rust/backend/rust-compile-expr.cc
+++ b/gcc/rust/backend/rust-compile-expr.cc
@@ -1199,9 +1199,14 @@ HIRCompileBase::resolve_adjustements (
 	  e = address_expression (e, locus);
 	  break;
 
-	case Resolver::Adjustment::AdjustmentType::DEREF_REF:
+	case Resolver::Adjustment::AdjustmentType::DEREF:
+	case Resolver::Adjustment::AdjustmentType::DEREF_MUT:
 	  e = resolve_deref_adjustment (adjustment, e, locus);
 	  break;
+
+	case Resolver::Adjustment::AdjustmentType::INDIRECTION:
+	  e = resolve_indirection_adjustment (adjustment, e, locus);
+	  break;
 	}
     }
 
@@ -1212,17 +1217,9 @@ tree
 HIRCompileBase::resolve_deref_adjustment (Resolver::Adjustment &adjustment,
 					  tree expression, Location locus)
 {
-  rust_assert (adjustment.is_deref_adjustment ());
-
-  tree expected_type
-    = TyTyResolveCompile::compile (ctx, adjustment.get_expected ());
-  if (!adjustment.has_operator_overload ())
-    {
-      return ctx->get_backend ()->indirect_expression (expected_type,
-						       expression,
-						       true, /* known_valid*/
-						       locus);
-    }
+  rust_assert (adjustment.is_deref_adjustment ()
+	       || adjustment.is_deref_mut_adjustment ());
+  rust_assert (adjustment.has_operator_overload ());
 
   TyTy::FnType *lookup = adjustment.get_deref_operator_fn ();
   HIR::ImplItem *resolved_item = adjustment.get_deref_hir_item ();
@@ -1246,13 +1243,19 @@ HIRCompileBase::resolve_deref_adjustment (Resolver::Adjustment &adjustment,
 
   // make the call
   auto fncontext = ctx->peek_fn ();
-  tree deref_call
-    = ctx->get_backend ()->call_expression (fncontext.fndecl, fn_address,
-					    {adjusted_argument}, nullptr,
-					    locus);
+  return ctx->get_backend ()->call_expression (fncontext.fndecl, fn_address,
+					       {adjusted_argument}, nullptr,
+					       locus);
+}
+
+tree
+HIRCompileBase::resolve_indirection_adjustment (
+  Resolver::Adjustment &adjustment, tree expression, Location locus)
+{
+  tree expected_type
+    = TyTyResolveCompile::compile (ctx, adjustment.get_expected ());
 
-  // do the indirect expression
-  return ctx->get_backend ()->indirect_expression (expected_type, deref_call,
+  return ctx->get_backend ()->indirect_expression (expected_type, expression,
 						   true, /* known_valid*/
 						   locus);
 }