From 4bb5de6c38058026af3b81768c91eb3596a9ab46 Mon Sep 17 00:00:00 2001
From: antego <antego@users.noreply.github.com>
Date: Tue, 10 May 2022 21:48:05 +1000
Subject: [PATCH] Implement name resolution for the IfLet expression.

Addresses #1177.
---
 gcc/rust/resolve/rust-ast-resolve-expr.cc | 25 +++++++++++++++++++++++
 gcc/rust/resolve/rust-ast-resolve-expr.h  |  2 ++
 2 files changed, 27 insertions(+)

diff --git a/gcc/rust/resolve/rust-ast-resolve-expr.cc b/gcc/rust/resolve/rust-ast-resolve-expr.cc
index 71af8c23205e..6e3bccb158d4 100644
--- a/gcc/rust/resolve/rust-ast-resolve-expr.cc
+++ b/gcc/rust/resolve/rust-ast-resolve-expr.cc
@@ -198,6 +198,31 @@ ResolveExpr::visit (AST::IfExprConseqIf &expr)
   resolve_expr (expr.get_conseq_if_expr ().get (), expr.get_node_id ());
 }
 
+void
+ResolveExpr::visit (AST::IfLetExpr &expr)
+{
+  resolve_expr (expr.get_value_expr().get (), expr.get_node_id ());
+
+  NodeId scope_node_id = expr.get_node_id ();
+  resolver->get_name_scope ().push (scope_node_id);
+  resolver->get_type_scope ().push (scope_node_id);
+  resolver->get_label_scope ().push (scope_node_id);
+  resolver->push_new_name_rib (resolver->get_name_scope ().peek ());
+  resolver->push_new_type_rib (resolver->get_type_scope ().peek ());
+  resolver->push_new_label_rib (resolver->get_type_scope ().peek ());
+
+  for (auto &pattern : expr.get_patterns ())
+    {
+      PatternDeclaration::go (pattern.get (), expr.get_node_id ());
+    }
+
+  resolve_expr (expr.get_if_block().get (), expr.get_node_id ());
+
+  resolver->get_name_scope ().pop ();
+  resolver->get_type_scope ().pop ();
+  resolver->get_label_scope ().pop ();
+}
+
 void
 ResolveExpr::visit (AST::BlockExpr &expr)
 {
diff --git a/gcc/rust/resolve/rust-ast-resolve-expr.h b/gcc/rust/resolve/rust-ast-resolve-expr.h
index 34a318d6d045..72e608532fda 100644
--- a/gcc/rust/resolve/rust-ast-resolve-expr.h
+++ b/gcc/rust/resolve/rust-ast-resolve-expr.h
@@ -69,6 +69,8 @@ class ResolveExpr : public ResolverBase
 
   void visit (AST::IfExprConseqIf &expr) override;
 
+  void visit (AST::IfLetExpr &expr) override;
+
   void visit (AST::BlockExpr &expr) override;
 
   void visit (AST::UnsafeBlockExpr &expr) override;