1 files changed, 76 insertions, 19 deletions

diff --git a/gcc/rust/expand/rust-macro-expand.h b/gcc/rust/expand/rust-macro-expand.h
index 88d0e6e..dd48cbd 100644
--- a/gcc/rust/expand/rust-macro-expand.h
+++ b/gcc/rust/expand/rust-macro-expand.h
@@ -54,32 +54,78 @@ struct MatchedFragment
   std::string fragment_ident;
   size_t token_offset_begin;
   size_t token_offset_end;
-  size_t match_amount;
 
   MatchedFragment (std::string identifier, size_t token_offset_begin,
-		   size_t token_offset_end, size_t match_amount = 1)
+		   size_t token_offset_end)
     : fragment_ident (identifier), token_offset_begin (token_offset_begin),
-      token_offset_end (token_offset_end), match_amount (match_amount)
+      token_offset_end (token_offset_end)
+  {}
+
+  /**
+   * Empty constructor for uninitialized fragments
+   */
+  MatchedFragment () : MatchedFragment ("", 0, 0) {}
+
+  std::string as_string () const
+  {
+    return fragment_ident + "=" + std::to_string (token_offset_begin) + ":"
+	   + std::to_string (token_offset_end);
+  }
+};
+
+class MatchedFragmentContainer
+{
+public:
+  MatchedFragmentContainer (std::vector<MatchedFragment> fragments)
+    : fragments (fragments)
   {}
 
   /**
    * Create a valid fragment matched zero times. This is useful for repetitions
    * which allow the absence of a fragment, such as * and ?
    */
-  static MatchedFragment zero (std::string identifier)
+  static MatchedFragmentContainer zero ()
   {
-    // We don't need offsets since there is "no match"
-    return MatchedFragment (identifier, 0, 0, 0);
+    return MatchedFragmentContainer ({});
   }
 
-  std::string as_string () const
+  /**
+   * Create a valid fragment matched one time
+   */
+  static MatchedFragmentContainer one (MatchedFragment fragment)
   {
-    return fragment_ident + "=" + std::to_string (token_offset_begin) + ":"
-	   + std::to_string (token_offset_end) + " (matched "
-	   + std::to_string (match_amount) + " times)";
+    return MatchedFragmentContainer ({fragment});
   }
 
-  void set_match_amount (size_t new_amount) { match_amount = new_amount; }
+  /**
+   * Add a matched fragment to the container
+   */
+  void add_fragment (MatchedFragment fragment)
+  {
+    fragments.emplace_back (fragment);
+  }
+
+  size_t get_match_amount () const { return fragments.size (); }
+  const std::vector<MatchedFragment> &get_fragments () const
+  {
+    return fragments;
+  }
+  // const std::string &get_fragment_name () const { return fragment_name; }
+
+  bool is_single_fragment () const { return get_match_amount () == 1; }
+  const MatchedFragment get_single_fragment () const
+  {
+    rust_assert (get_match_amount () == 1);
+
+    return fragments[0];
+  }
+
+private:
+  /**
+   * Fragments matched `match_amount` times. This can be an empty vector
+   * in case having zero matches is allowed (i.e ? or * operators)
+   */
+  std::vector<MatchedFragment> fragments;
 };
 
 class SubstitutionScope
@@ -89,18 +135,21 @@ public:
 
   void push () { stack.push_back ({}); }
 
-  std::map<std::string, std::vector<MatchedFragment>> pop ()
+  std::map<std::string, MatchedFragmentContainer> pop ()
   {
     auto top = stack.back ();
     stack.pop_back ();
     return top;
   }
 
-  std::map<std::string, std::vector<MatchedFragment>> &peek ()
+  std::map<std::string, MatchedFragmentContainer> &peek ()
   {
     return stack.back ();
   }
 
+  /**
+   * Insert a new matched fragment into the current substitution map
+   */
   void insert_fragment (MatchedFragment fragment)
   {
     auto &current_map = stack.back ();
@@ -108,19 +157,27 @@ public:
 
     if (it == current_map.end ())
       {
-	auto new_frags = std::vector<MatchedFragment> ();
-	new_frags.emplace_back (fragment);
-	current_map.insert ({fragment.fragment_ident, new_frags});
+	current_map.insert (
+	  {fragment.fragment_ident, MatchedFragmentContainer::one (fragment)});
       }
     else
       {
 	auto &frags = it->second;
-	frags.emplace_back (fragment);
+	frags.add_fragment (fragment);
       }
   }
 
+  void insert_matches (std::string key, MatchedFragmentContainer matches)
+  {
+    auto &current_map = stack.back ();
+    auto it = current_map.find (key);
+    rust_assert (it == current_map.end ());
+
+    current_map.insert ({key, matches});
+  }
+
 private:
-  std::vector<std::map<std::string, std::vector<MatchedFragment>>> stack;
+  std::vector<std::map<std::string, MatchedFragmentContainer>> stack;
 };
 
 // Object used to store shared data (between functions) for macro expansion.
@@ -174,7 +231,7 @@ struct MacroExpander
 
   AST::ASTFragment transcribe_rule (
     AST::MacroRule &match_rule, AST::DelimTokenTree &invoc_token_tree,
-    std::map<std::string, std::vector<MatchedFragment>> &matched_fragments,
+    std::map<std::string, MatchedFragmentContainer> &matched_fragments,
     bool semicolon, ContextType ctx);
 
   bool match_fragment (Parser<MacroInvocLexer> &parser,