gccrs: Change lookup_hir_pattern return type

Wrap the function's return type within an optional in order to
differentiate between a null pointer and a missing value.

gcc/rust/ChangeLog:

	* util/rust-hir-map.cc (Mappings::insert_hir_pattern): Change call site
	in order to accomodate new return type.
	(Mappings::lookup_hir_pattern): 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>

2 files changed, 4 insertions, 4 deletions

diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index d1f55a3..2ac6141 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -692,18 +692,18 @@ void
 Mappings::insert_hir_pattern (HIR::Pattern *pattern)
 {
   auto id = pattern->get_mappings ().get_hirid ();
-  rust_assert (lookup_hir_pattern (id) == nullptr);
+  rust_assert (!lookup_hir_pattern (id));
 
   hirPatternMappings[id] = pattern;
   insert_node_to_hir (pattern->get_mappings ().get_nodeid (), id);
 }
 
-HIR::Pattern *
+tl::optional<HIR::Pattern *>
 Mappings::lookup_hir_pattern (HirId id)
 {
   auto it = hirPatternMappings.find (id);
   if (it == hirPatternMappings.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 740a8e6..c556d76 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -170,7 +170,7 @@ public:
   tl::optional<HIR::StructExprField *> lookup_hir_struct_field (HirId id);
 
   void insert_hir_pattern (HIR::Pattern *pattern);
-  HIR::Pattern *lookup_hir_pattern (HirId id);
+  tl::optional<HIR::Pattern *> lookup_hir_pattern (HirId id);
 
   void walk_local_defids_for_crate (CrateNum crateNum,
 				    std::function<bool (HIR::Item *)> cb);