[gcc/devel/rust/master] Add name resolution to ForLoopExpr

[Thomas Schwinge <tschwinge@gcc.gnu.org>]

https://gcc.gnu.org/g:f6589ca957b2a1d0bea6c43dd60e37b06cb04ab3

commit f6589ca957b2a1d0bea6c43dd60e37b06cb04ab3
Author: Philip Herron <philip.herron@embecosm.com>
Date:   Wed Jun 1 10:53:04 2022 +0100

    Add name resolution to ForLoopExpr

Diff:
---
 gcc/rust/resolve/rust-ast-resolve-expr.cc | 47 +++++++++++++++++++++++++++++++
 gcc/rust/resolve/rust-ast-resolve-expr.h  |  2 ++
 2 files changed, 49 insertions(+)

diff --git a/gcc/rust/resolve/rust-ast-resolve-expr.cc b/gcc/rust/resolve/rust-ast-resolve-expr.cc
index 402c0488277..4bf35efdbbe 100644
--- a/gcc/rust/resolve/rust-ast-resolve-expr.cc
+++ b/gcc/rust/resolve/rust-ast-resolve-expr.cc
@@ -420,6 +420,53 @@ ResolveExpr::visit (AST::WhileLoopExpr &expr)
   resolve_expr (expr.get_loop_block ().get (), expr.get_node_id ());
 }
 
+void
+ResolveExpr::visit (AST::ForLoopExpr &expr)
+{
+  if (expr.has_loop_label ())
+    {
+      auto label = expr.get_loop_label ();
+      if (label.get_lifetime ().get_lifetime_type ()
+	  != AST::Lifetime::LifetimeType::NAMED)
+	{
+	  rust_error_at (label.get_locus (),
+			 "Labels must be a named lifetime value");
+	  return;
+	}
+
+      auto label_name = label.get_lifetime ().get_lifetime_name ();
+      auto label_lifetime_node_id = label.get_lifetime ().get_node_id ();
+      resolver->get_label_scope ().insert (
+	CanonicalPath::new_seg (label.get_node_id (), label_name),
+	label_lifetime_node_id, label.get_locus (), false,
+	[&] (const CanonicalPath &, NodeId, Location locus) -> void {
+	  rust_error_at (label.get_locus (), "label redefined multiple times");
+	  rust_error_at (locus, "was defined here");
+	});
+      resolver->insert_new_definition (label_lifetime_node_id,
+				       Definition{label_lifetime_node_id,
+						  label.get_node_id ()});
+    }
+
+  // this needs a new rib to contain the pattern
+  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 ());
+
+  // resolve the expression
+  PatternDeclaration::go (expr.get_pattern ().get (), expr.get_node_id ());
+  resolve_expr (expr.get_iterator_expr ().get (), expr.get_node_id ());
+  resolve_expr (expr.get_loop_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::ContinueExpr &expr)
 {
diff --git a/gcc/rust/resolve/rust-ast-resolve-expr.h b/gcc/rust/resolve/rust-ast-resolve-expr.h
index 72e608532fd..4f189decc9d 100644
--- a/gcc/rust/resolve/rust-ast-resolve-expr.h
+++ b/gcc/rust/resolve/rust-ast-resolve-expr.h
@@ -99,6 +99,8 @@ public:
 
   void visit (AST::WhileLoopExpr &expr) override;
 
+  void visit (AST::ForLoopExpr &expr) override;
+
   void visit (AST::ContinueExpr &expr) override;
 
   void visit (AST::BorrowExpr &expr) override;