macros: Do not try and re-expand if depth has exceeded recursion limit

We need to limit the amount of times that macro get expanded recursively
during macro-expansion. This limits the amount of times an ASTFragment
can be visited by simply incrementing the depth when setting a fragment,
and decreasing it when taking one. This way, recursive expansion which
happens at the expansion level (instead of the matching level) will
still get caught

1 files changed, 8 insertions, 1 deletions

diff --git a/gcc/rust/expand/rust-macro-expand.h b/gcc/rust/expand/rust-macro-expand.h
index 4efcd7b..0d0282e 100644
--- a/gcc/rust/expand/rust-macro-expand.h
+++ b/gcc/rust/expand/rust-macro-expand.h
@@ -287,11 +287,18 @@ struct MacroExpander
     expanded_fragment = std::move (fragment);
   }
 
-  AST::ASTFragment take_expanded_fragment ()
+  AST::ASTFragment take_expanded_fragment (AST::ASTVisitor &vis)
   {
     AST::ASTFragment old_fragment = std::move (expanded_fragment);
     expanded_fragment = AST::ASTFragment::create_empty ();
 
+    for (auto &node : old_fragment.get_nodes ())
+      {
+	expansion_depth++;
+	node.accept_vis (vis);
+	expansion_depth--;
+      }
+
     return old_fragment;
   }