From: Philip Herron <herron.philip@googlemail.com>
Date: Mon, 19 May 2025 16:42:17 +0000 (+0100)
Subject: gccrs: Remove unneeded clones untill we have an arena allocator for these tmps
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3c72ed2e711c4cb17fea8e13fa055e2f64dcdcd1;p=thirdparty%2Fgcc.git

gccrs: Remove unneeded clones untill we have an arena allocator for these tmps

Cloning inference variables is very expensive because it means we are indirectly
creating an implicit new inference variable added to the reference chain.

gcc/rust/ChangeLog:

	* checks/errors/privacy/rust-privacy-reporter.cc (PrivacyReporter::check_base_type_privacy):
	no need for unreachable here
	* typecheck/rust-unify.cc (UnifyRules::commit): dont clone infer vars
	(UnifyRules::expect_inference_variable): likewise

Signed-off-by: Philip Herron <herron.philip@googlemail.com>
---

diff --git a/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc b/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc
index 3faa3b404e6..e1d4b167d3d 100644
--- a/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc
+++ b/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc
@@ -221,8 +221,9 @@ PrivacyReporter::check_base_type_privacy (Analysis::NodeMapping &node_mappings,
 	auto ref_id = ty->get_ref ();
 	if (auto lookup_id = mappings.lookup_hir_to_node (ref_id))
 	  return check_for_privacy_violation (*lookup_id, locus);
-	rust_unreachable ();
       }
+      break;
+
     case TyTy::REF:
       return recursive_check (
 	static_cast<const TyTy::ReferenceType *> (ty)->get_base ());
diff --git a/gcc/rust/typecheck/rust-unify.cc b/gcc/rust/typecheck/rust-unify.cc
index 0ffab667433..6699f7e46b5 100644
--- a/gcc/rust/typecheck/rust-unify.cc
+++ b/gcc/rust/typecheck/rust-unify.cc
@@ -69,7 +69,6 @@ UnifyRules::commit (TyTy::BaseType *base, TyTy::BaseType *other,
 		    TyTy::BaseType *resolved)
 {
   TypeCheckContext &context = *TypeCheckContext::get ();
-  Analysis::Mappings &mappings = Analysis::Mappings::get ();
 
   TyTy::BaseType *b = base->destructure ();
   TyTy::BaseType *o = other->destructure ();
@@ -102,13 +101,8 @@ UnifyRules::commit (TyTy::BaseType *base, TyTy::BaseType *other,
 	    continue;
 
 	  // if any of the types are inference variables lets fix them
-	  if (ref_tyty->get_kind () == TyTy::TypeKind::INFER)
-	    {
-	      auto node = Analysis::NodeMapping (mappings.get_current_crate (),
-						 UNKNOWN_NODEID, ref,
-						 UNKNOWN_LOCAL_DEFID);
-	      context.insert_type (node, resolved->clone ());
-	    }
+	  if (ref_tyty->is<TyTy::InferType> ())
+	    context.insert_implicit_type (ref, resolved);
 	}
     }
 }
@@ -343,7 +337,7 @@ UnifyRules::expect_inference_variable (TyTy::InferType *ltype,
 			      || r->get_infer_kind ()
 				   == TyTy::InferType::InferTypeKind::GENERAL;
 	      if (is_valid)
-		return rtype->clone ();
+		return rtype;
 	    }
 	    break;
 
@@ -354,7 +348,7 @@ UnifyRules::expect_inference_variable (TyTy::InferType *ltype,
 		  || r->get_infer_kind ()
 		       == TyTy::InferType::InferTypeKind::GENERAL;
 	      if (is_valid)
-		return rtype->clone ();
+		return rtype;
 	    }
 	    break;
 	  }
@@ -373,7 +367,7 @@ UnifyRules::expect_inference_variable (TyTy::InferType *ltype,
 	if (is_valid)
 	  {
 	    ltype->apply_primitive_type_hint (*rtype);
-	    return rtype->clone ();
+	    return rtype;
 	  }
       }
       break;
@@ -387,7 +381,7 @@ UnifyRules::expect_inference_variable (TyTy::InferType *ltype,
 	if (is_valid)
 	  {
 	    ltype->apply_primitive_type_hint (*rtype);
-	    return rtype->clone ();
+	    return rtype;
 	  }
       }
       break;