gccrs: ast: Improve Fragment API

gcc/rust/ChangeLog:

	* ast/rust-ast-fragment.cc (Fragment::Fragment): Add better APIs.
	(Fragment::complete): New function.
	(Fragment::unexpanded): New function.
	* ast/rust-ast-fragment.h: Declare new APIs and add documentation.
	* expand/rust-attribute-visitor.h: Use new Fragment API.
	* expand/rust-macro-builtins.cc (MacroBuiltin::file): Likewise.
	(MacroBuiltin::column): Likewise.
	(MacroBuiltin::include_bytes): Likewise.
	(MacroBuiltin::include_str): Likewise.
	(MacroBuiltin::concat): Likewise.
	(MacroBuiltin::env): Likewise.
	(MacroBuiltin::cfg): Likewise.
	(MacroBuiltin::include): Likewise.
	(MacroBuiltin::line): Likewise.
	* expand/rust-macro-expand.cc (parse_many): Likewise.
	(transcribe_expression): Likewise.
	(transcribe_type): Likewise.
	* expand/rust-macro-expand.h (struct MacroExpander): Likewise.

1 files changed, 17 insertions, 14 deletions

diff --git a/gcc/rust/ast/rust-ast-fragment.cc b/gcc/rust/ast/rust-ast-fragment.cc
index 1a2dd99..c491609 100644
--- a/gcc/rust/ast/rust-ast-fragment.cc
+++ b/gcc/rust/ast/rust-ast-fragment.cc
@@ -21,22 +21,13 @@
 namespace Rust {
 namespace AST {
 
-Fragment::Fragment (std::vector<SingleASTNode> nodes, bool fragment_is_error)
-  : kind (fragment_is_error ? FragmentKind::Error : FragmentKind::Complete),
-    nodes (std::move (nodes))
-{
-  if (fragment_is_error)
-    rust_assert (nodes.empty ());
-}
+Fragment::Fragment (FragmentKind kind, std::vector<SingleASTNode> nodes)
+  : kind (kind), nodes (std::move (nodes))
+{}
 
 Fragment::Fragment (Fragment const &other) : kind (other.get_kind ())
 {
-  nodes.clear ();
-  nodes.reserve (other.nodes.size ());
-  for (auto &n : other.nodes)
-    {
-      nodes.push_back (n);
-    }
+  *this = other;
 }
 
 Fragment &
@@ -56,7 +47,19 @@ Fragment::operator= (Fragment const &other)
 Fragment
 Fragment::create_error ()
 {
-  return Fragment ({}, true);
+  return Fragment (FragmentKind::Error, {});
+}
+
+Fragment
+Fragment::complete (std::vector<AST::SingleASTNode> nodes)
+{
+  return Fragment (FragmentKind::Complete, std::move (nodes));
+}
+
+Fragment
+Fragment::unexpanded ()
+{
+  return Fragment (FragmentKind::Unexpanded, {});
 }
 
 std::vector<SingleASTNode> &