[COMMITTED 043/145] gccrs: Change lookup_hir_struct_field return type

[arthur . cohen]

From: Pierre-Emmanuel Patry <pierre-emmanuel.pa...@embecosm.com>

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

gcc/rust/ChangeLog:

        * util/rust-hir-map.cc (Mappings::insert_hir_struct_field): Change
        call site to accomodate new return type.
        (Mappings::lookup_hir_struct_field): Change the function's return
        type.
        * util/rust-hir-map.h: Update the function's prototype.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.pa...@embecosm.com>
---
 gcc/rust/util/rust-hir-map.cc | 6 +++---
 gcc/rust/util/rust-hir-map.h  | 2 +-
 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 f124be8b998..d1f55a372ac 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -672,18 +672,18 @@ void
 Mappings::insert_hir_struct_field (HIR::StructExprField *field)
 {
   auto id = field->get_mappings ().get_hirid ();
-  rust_assert (lookup_hir_struct_field (id) == nullptr);
+  rust_assert (!lookup_hir_struct_field (id));
 
   hirStructFieldMappings[id] = field;
   insert_node_to_hir (field->get_mappings ().get_nodeid (), id);
 }
 
-HIR::StructExprField *
+tl::optional<HIR::StructExprField *>
 Mappings::lookup_hir_struct_field (HirId id)
 {
   auto it = hirStructFieldMappings.find (id);
   if (it == hirStructFieldMappings.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 720dd976af4..740a8e6d499 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -167,7 +167,7 @@ public:
   tl::optional<HIR::SelfParam *> lookup_hir_self_param (HirId id);
 
   void insert_hir_struct_field (HIR::StructExprField *type);
-  HIR::StructExprField *lookup_hir_struct_field (HirId id);
+  tl::optional<HIR::StructExprField *> lookup_hir_struct_field (HirId id);
 
   void insert_hir_pattern (HIR::Pattern *pattern);
   HIR::Pattern *lookup_hir_pattern (HirId id);
-- 
2.45.2