Parse box expressions

Add support for old box expression syntax.

gcc/rust/ChangeLog:

	* ast/rust-ast-collector.cc (TokenCollector::visit): Add visit member
	function for BoxExpr nodes.
	* ast/rust-ast-collector.h: Add visit function prototype.
	* ast/rust-ast-visitor.cc (DefaultASTVisitor::visit): Add visit member
	function to default ast visitor.
	* ast/rust-ast-visitor.h: Add visit function's prototype.
	* ast/rust-ast.cc (BoxExpr::as_string): Add as_string function
	implementation for BoxExpr.
	(BoxExpr::accept_vis): Add accept_vis implementation to BoxExpr.
	* ast/rust-expr.h (class BoxExpr): Add BoxExpr class to represent boxed
	expressions.
	* expand/rust-derive.h: Add BoxExpr visit function prototype.
	* hir/rust-ast-lower-base.cc (ASTLoweringBase::visit): Add BoxExpr
	visitor implementation.
	* hir/rust-ast-lower-base.h: Add visit function's prototype.
	* hir/rust-ast-lower-expr.cc (ASTLoweringExpr::visit): Add BoxExpr
	visitor implementation.
	* hir/rust-ast-lower-expr.h: Add visit function's prototype.
	* parse/rust-parse-impl.h (Parser::parse_box_expr): Add parse_box_expr
	function's implementation.
	* parse/rust-parse.h: Add parse_box_expr function's prototype.
	* resolve/rust-ast-resolve-base.cc (ResolverBase::visit): Add resolver
	visit implementation.
	* resolve/rust-ast-resolve-base.h: Add resolver's visit function
	prototype.

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

4 files changed, 15 insertions, 0 deletions

diff --git a/gcc/rust/hir/rust-ast-lower-base.cc b/gcc/rust/hir/rust-ast-lower-base.cc
index 66cff8f..fc37b50 100644
--- a/gcc/rust/hir/rust-ast-lower-base.cc
+++ b/gcc/rust/hir/rust-ast-lower-base.cc
@@ -213,6 +213,11 @@ ASTLoweringBase::visit (AST::RangeFromToInclExpr &)
 void
 ASTLoweringBase::visit (AST::RangeToInclExpr &)
 {}
+
+void
+ASTLoweringBase::visit (AST::BoxExpr &)
+{}
+
 void
 ASTLoweringBase::visit (AST::ReturnExpr &)
 {}
diff --git a/gcc/rust/hir/rust-ast-lower-base.h b/gcc/rust/hir/rust-ast-lower-base.h
index cacd8c1..d477739 100644
--- a/gcc/rust/hir/rust-ast-lower-base.h
+++ b/gcc/rust/hir/rust-ast-lower-base.h
@@ -137,6 +137,7 @@ public:
   virtual void visit (AST::RangeFullExpr &expr);
   virtual void visit (AST::RangeFromToInclExpr &expr);
   virtual void visit (AST::RangeToInclExpr &expr);
+  virtual void visit (AST::BoxExpr &expr);
   virtual void visit (AST::ReturnExpr &expr);
   virtual void visit (AST::UnsafeBlockExpr &expr);
   virtual void visit (AST::LoopExpr &expr);
diff --git a/gcc/rust/hir/rust-ast-lower-expr.cc b/gcc/rust/hir/rust-ast-lower-expr.cc
index 35d542b..3b462ee 100644
--- a/gcc/rust/hir/rust-ast-lower-expr.cc
+++ b/gcc/rust/hir/rust-ast-lower-expr.cc
@@ -24,6 +24,7 @@
 #include "rust-ast-lower-type.h"
 #include "rust-ast.h"
 #include "rust-diagnostics.h"
+#include "rust-system.h"
 
 namespace Rust {
 namespace HIR {
@@ -142,6 +143,13 @@ ASTLoweringExpr::visit (AST::QualifiedPathInExpression &expr)
 }
 
 void
+ASTLoweringExpr::visit (AST::BoxExpr &expr)
+{
+  // Not implemented
+  rust_unreachable ();
+}
+
+void
 ASTLoweringExpr::visit (AST::ReturnExpr &expr)
 {
   terminated = true;
diff --git a/gcc/rust/hir/rust-ast-lower-expr.h b/gcc/rust/hir/rust-ast-lower-expr.h
index ab3ae0a..e145259 100644
--- a/gcc/rust/hir/rust-ast-lower-expr.h
+++ b/gcc/rust/hir/rust-ast-lower-expr.h
@@ -85,6 +85,7 @@ public:
   void visit (AST::UnsafeBlockExpr &expr) override;
   void visit (AST::PathInExpression &expr) override;
   void visit (AST::QualifiedPathInExpression &expr) override;
+  void visit (AST::BoxExpr &expr) override;
   void visit (AST::ReturnExpr &expr) override;
   void visit (AST::CallExpr &expr) override;
   void visit (AST::MethodCallExpr &expr) override;