lowering: Add lowering of exported macros

Macros marked with #[macro_export] need to be lowered to HIR in order
to get exported to the relevant metadata files.

gcc/rust/ChangeLog:

	* hir/rust-ast-lower-base.cc (ASTLoweringBase::lower_macro_definition):
	New function.
	* hir/rust-ast-lower-base.h: Declare `lower_macro_definition`.
	* hir/rust-ast-lower-item.cc (ASTLoweringItem::visit): Lower public
	macro definitions.
	* hir/rust-ast-lower-stmt.cc (ASTLoweringStmt::visit): Likewise.
	* hir/rust-ast-lower-stmt.h: Add visitor for `AST::MacroRulesDefinition`.
	* hir/rust-ast-lower.cc (ASTLowering::go): Formatting.
	(ASTLoweringBlock::visit): Visit `AST::MacroRulesDefinition`
	(ASTLoweringIfLetBlock::visit): Formatting.
	(ASTLoweringExprWithBlock::visit): Formatting.

1 files changed, 7 insertions, 8 deletions

diff --git a/gcc/rust/hir/rust-ast-lower.cc b/gcc/rust/hir/rust-ast-lower.cc
index c2fd54d..9b6227c 100644
--- a/gcc/rust/hir/rust-ast-lower.cc
+++ b/gcc/rust/hir/rust-ast-lower.cc
@@ -72,7 +72,7 @@ ASTLowering::Resolve (AST::Crate &astCrate)
 std::unique_ptr<HIR::Crate>
 ASTLowering::go ()
 {
-  std::vector<std::unique_ptr<HIR::Item> > items;
+  std::vector<std::unique_ptr<HIR::Item>> items;
 
   for (auto it = astCrate.items.begin (); it != astCrate.items.end (); it++)
     {
@@ -95,14 +95,11 @@ ASTLowering::go ()
 void
 ASTLoweringBlock::visit (AST::BlockExpr &expr)
 {
-  std::vector<std::unique_ptr<HIR::Stmt> > block_stmts;
+  std::vector<std::unique_ptr<HIR::Stmt>> block_stmts;
   bool block_did_terminate = false;
 
   for (auto &s : expr.get_statements ())
     {
-      if (s->get_ast_kind () == AST::Kind::MACRO_RULES_DEFINITION)
-	continue;
-
       if (s->get_ast_kind () == AST::Kind::MACRO_INVOCATION)
 	rust_fatal_error (
 	  s->get_locus (),
@@ -115,8 +112,10 @@ ASTLoweringBlock::visit (AST::BlockExpr &expr)
 
       bool terminated = false;
       auto translated_stmt = ASTLoweringStmt::translate (s.get (), &terminated);
-      block_stmts.push_back (std::unique_ptr<HIR::Stmt> (translated_stmt));
       block_did_terminate |= terminated;
+
+      if (translated_stmt)
+	block_stmts.push_back (std::unique_ptr<HIR::Stmt> (translated_stmt));
     }
 
   if (expr.has_tail_expr () && block_did_terminate)
@@ -230,7 +229,7 @@ ASTLoweringIfBlock::visit (AST::IfExprConseqIf &expr)
 void
 ASTLoweringIfLetBlock::visit (AST::IfLetExpr &expr)
 {
-  std::vector<std::unique_ptr<HIR::Pattern> > patterns;
+  std::vector<std::unique_ptr<HIR::Pattern>> patterns;
   for (auto &pattern : expr.get_patterns ())
     {
       HIR::Pattern *ptrn = ASTLoweringPattern::translate (pattern.get ());
@@ -372,7 +371,7 @@ ASTLoweringExprWithBlock::visit (AST::MatchExpr &expr)
 	    match_case.get_arm ().get_guard_expr ().get ());
 	}
 
-      std::vector<std::unique_ptr<HIR::Pattern> > match_arm_patterns;
+      std::vector<std::unique_ptr<HIR::Pattern>> match_arm_patterns;
       for (auto &pattern : match_case.get_arm ().get_patterns ())
 	{
 	  HIR::Pattern *ptrn = ASTLoweringPattern::translate (pattern.get ());