Change lookup_module function return type

Wrap the return type into an optional.

gcc/rust/ChangeLog:

	* checks/errors/privacy/rust-visibility-resolver.cc: Update function
	call to match the new return type.
	* typecheck/rust-hir-type-check-path.cc (TypeCheckExpr::resolve_root_path):
	Likewise.
	* typecheck/rust-hir-type-check-type.cc (TypeCheckType::resolve_root_path):
	Likewise.
	* util/rust-hir-map.cc (Mappings::insert_module): Likewise.
	(Mappings::lookup_module): Change the function's return type.
	* util/rust-hir-map.h: Update the function's prototype.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

5 files changed, 13 insertions, 15 deletions

diff --git a/gcc/rust/checks/errors/privacy/rust-visibility-resolver.cc b/gcc/rust/checks/errors/privacy/rust-visibility-resolver.cc
index 5854b46..7110883 100644
--- a/gcc/rust/checks/errors/privacy/rust-visibility-resolver.cc
+++ b/gcc/rust/checks/errors/privacy/rust-visibility-resolver.cc
@@ -85,17 +85,15 @@ VisibilityResolver::resolve_module_path (const HIR::SimplePath &restriction,
     // these items as private?
     return true;
 
-  auto module = mappings.lookup_module (ref);
-  if (!module)
+  if (auto module = mappings.lookup_module (ref))
     {
-      invalid_path.emit ();
-      return false;
-    }
+      // Fill in the resolved `DefId`
+      id = module.value ()->get_mappings ().get_defid ();
 
-  // Fill in the resolved `DefId`
-  id = module->get_mappings ().get_defid ();
-
-  return true;
+      return true;
+    }
+  invalid_path.emit ();
+  return false;
 }
 
 bool
diff --git a/gcc/rust/typecheck/rust-hir-type-check-path.cc b/gcc/rust/typecheck/rust-hir-type-check-path.cc
index 9e284f2..d2962e6 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-path.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-path.cc
@@ -243,7 +243,7 @@ TypeCheckExpr::resolve_root_path (HIR::PathInExpression &expr, size_t *offset,
 	}
       auto ref = hid.value ();
 
-      auto seg_is_module = (nullptr != mappings.lookup_module (ref));
+      auto seg_is_module = mappings.lookup_module (ref).has_value ();
       auto seg_is_crate = mappings.is_local_hirid_crate (ref);
       if (seg_is_module || seg_is_crate)
 	{
diff --git a/gcc/rust/typecheck/rust-hir-type-check-type.cc b/gcc/rust/typecheck/rust-hir-type-check-type.cc
index c7bfee5..36f64a7 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-type.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-type.cc
@@ -391,7 +391,7 @@ TypeCheckType::resolve_root_path (HIR::TypePath &path, size_t *offset,
 	}
       auto ref = hid.value ();
 
-      auto seg_is_module = (nullptr != mappings.lookup_module (ref));
+      auto seg_is_module = mappings.lookup_module (ref).has_value ();
       auto seg_is_crate = mappings.is_local_hirid_crate (ref);
       if (seg_is_module || seg_is_crate)
 	{
diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index aee3ef8..97d7abf 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -489,18 +489,18 @@ void
 Mappings::insert_module (HIR::Module *module)
 {
   auto id = module->get_mappings ().get_hirid ();
-  rust_assert (lookup_module (id) == nullptr);
+  rust_assert (!lookup_module (id));
 
   hirModuleMappings[id] = module;
   insert_node_to_hir (module->get_mappings ().get_nodeid (), id);
 }
 
-HIR::Module *
+tl::optional<HIR::Module *>
 Mappings::lookup_module (HirId id)
 {
   auto it = hirModuleMappings.find (id);
   if (it == hirModuleMappings.end ())
-    return nullptr;
+    return tl::nullopt;
 
   return it->second;
 }
diff --git a/gcc/rust/util/rust-hir-map.h b/gcc/rust/util/rust-hir-map.h
index 1171945..b18c60c 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -138,7 +138,7 @@ public:
   tl::optional<HIR::ImplBlock *> lookup_impl_block_type (HirId id);
 
   void insert_module (HIR::Module *module);
-  HIR::Module *lookup_module (HirId id);
+  tl::optional<HIR::Module *> lookup_module (HirId id);
 
   void insert_hir_implitem (HirId parent_impl_id, HIR::ImplItem *item);
   HIR::ImplItem *lookup_hir_implitem (HirId id, HirId *parent_impl_id);