dump: Add formatting to dump

Add formatting character output to ast dump.

gcc/rust/ChangeLog:

	* ast/rust-ast-collector.cc (TokenCollector::visit): Add comment
	after tail expressions.
	* ast/rust-ast-dump.cc (Dump::require_spacing): Check for
	missing previous token.
	* ast/rust-ast-dump.h: Output formatting characters.

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

3 files changed, 34 insertions, 7 deletions

diff --git a/gcc/rust/ast/rust-ast-collector.cc b/gcc/rust/ast/rust-ast-collector.cc
index 89c693e..38eb317 100644
--- a/gcc/rust/ast/rust-ast-collector.cc
+++ b/gcc/rust/ast/rust-ast-collector.cc
@@ -1276,6 +1276,7 @@ TokenCollector::visit (BlockExpr &expr)
   if (expr.has_tail_expr ())
     {
       visit (expr.get_tail_expr ());
+      comment ("tail expr");
       newline ();
     }
 
diff --git a/gcc/rust/ast/rust-ast-dump.cc b/gcc/rust/ast/rust-ast-dump.cc
index dae93cf..3243e34 100644
--- a/gcc/rust/ast/rust-ast-dump.cc
+++ b/gcc/rust/ast/rust-ast-dump.cc
@@ -27,6 +27,11 @@ Dump::Dump (std::ostream &stream) : stream (stream), indentation (Indent ()) {}
 bool
 Dump::require_spacing (TokenPtr previous, TokenPtr current)
 {
+  if (previous == nullptr)
+    {
+      return false;
+    }
+
   switch (current->get_id ())
     {
     case EXCLAM:
diff --git a/gcc/rust/ast/rust-ast-dump.h b/gcc/rust/ast/rust-ast-dump.h
index 16c43f3..d0e0277 100644
--- a/gcc/rust/ast/rust-ast-dump.h
+++ b/gcc/rust/ast/rust-ast-dump.h
@@ -44,14 +44,35 @@ public:
     TokenCollector collector;
     collector.visit (v);
 
-    auto tokens = collector.collect_tokens ();
-    if (!tokens.empty ())
-      stream << tokens.front ()->as_string ();
-    for (auto it = tokens.cbegin () + 1; it < tokens.cend (); it++)
+    TokenPtr previous = nullptr;
+    for (auto item : collector.collect ())
       {
-	if (require_spacing (*(it - 1), *it))
-	  stream << " ";
-	stream << (*it)->as_string ();
+	switch (item.get_kind ())
+	  {
+	    case AST::CollectItem::Kind::Token: {
+	      TokenPtr current = item.get_token ();
+	      if (require_spacing (previous, current))
+		stream << " ";
+	      stream << current->as_string ();
+	      previous = current;
+	    }
+	    break;
+	  case AST::CollectItem::Kind::Comment:
+	    stream << " /* " << item.get_comment () << " */ ";
+	    break;
+	  case AST::CollectItem::Kind::Indentation:
+	    for (size_t i = 0; i < item.get_indent_level (); i++)
+	      {
+		stream << "    ";
+	      }
+	    break;
+	  case AST::CollectItem::Kind::Newline:
+	    stream << "\n";
+	    previous = nullptr;
+	    break;
+	  default:
+	    gcc_unreachable ();
+	  }
       }
   }