gccrs: resolve: Add mappings for proc macros and resolving

Add multiple mappings for procedural macro name resolution.
Procedural macros were not resolved using name resolution and mapping
but rather with some hacky path comparison.

gcc/rust/ChangeLog:

	* expand/rust-macro-expand.cc (MacroExpander::import_proc_macros):
	Remove function.
	* expand/rust-macro-expand.h (struct MacroExpander): Remove
	import_proc_macro function.
	* util/rust-hir-map.cc (Mappings::insert_derive_proc_macro_def):
	Add a function to insert a derive proc macro definition.
	(Mappings::insert_bang_proc_macro): Remove function.
	(Mappings::insert_bang_proc_macro_def): Add function to insert a
	bang proc macro definition.
	(Mappings::insert_attribute_proc_macro_def): Likewise with
	attribute proc macros.
	(Mappings::lookup_derive_proc_macro_def): Add a function to
	lookup a defined derive proc macro definition.
	(Mappings::lookup_bang_proc_macro): Remove function.
	(Mappings::lookup_bang_proc_macro_def): Add a function to lookup
	a bang proc macro definition.
	(Mappings::lookup_attribute_proc_macro_def): Add a function to
	lookup an attribute prod macro definition.
	(Mappings::insert_derive_proc_macro_invocation): Add a function
	to insert a derive proc macro invocation.
	(Mappings::lookup_derive_proc_macro_invocation): Add a function
	to lookup a derive proc macro invocation.
	(Mappings::insert_bang_proc_macro_invocation): Add a function to
	insert a bang proc macro invocation.
	(Mappings::lookup_bang_proc_macro_invocation): Add a function to
	lookup a bang proc macro invocation.
	(Mappings::insert_attribute_proc_macro_invocation): Add a
	function to insert an attribute proc macro invocation.
	(Mappings::lookup_attribute_proc_macro_invocation): Add a
	function to lookup an attribute proc macro invocation.
	* util/rust-hir-map.h: Add different proc macro mappings
	and change function prototypes.
	* expand/rust-expand-visitor.cc (get_traits_to_derive): Return a
	vector of SimplePath instead.
	(derive_item): Accept SimplePath instead of a string.
	* ast/rust-ast.h: Add common ProcMacroInvocable interface to
	Identifiers and SimplePath nodes.
	* ast/rust-ast.cc: Add const modifier.
	* ast/rust-macro.h: Change path and identifier getters.
	* ast/rust-path.h: Change return type to reference.

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

10 files changed, 215 insertions, 180 deletions

diff --git a/gcc/rust/ast/rust-ast.cc b/gcc/rust/ast/rust-ast.cc
index 699232c..eb133aa 100644
--- a/gcc/rust/ast/rust-ast.cc
+++ b/gcc/rust/ast/rust-ast.cc
@@ -173,7 +173,7 @@ SimplePathSegment::as_string () const
   return segment_name;
 }
 
-std::string
+const std::string
 SimplePath::as_string () const
 {
   std::string path;
diff --git a/gcc/rust/ast/rust-ast.h b/gcc/rust/ast/rust-ast.h
index faf14fe..5be6932 100644
--- a/gcc/rust/ast/rust-ast.h
+++ b/gcc/rust/ast/rust-ast.h
@@ -25,6 +25,7 @@
 #include "rust-token.h"
 #include "rust-location.h"
 #include "rust-diagnostics.h"
+#include "rust-proc-macro-invocation.h"
 
 namespace Rust {
 // TODO: remove typedefs and make actual types for these
@@ -32,7 +33,7 @@ typedef int TupleIndex;
 struct Session;
 struct MacroExpander;
 
-class Identifier
+class Identifier : public ProcMacroInvocable
 {
 public:
   // Create dummy identifier
@@ -59,7 +60,7 @@ public:
 
   NodeId get_node_id () const { return node_id; }
   location_t get_locus () const { return loc; }
-  const std::string &as_string () const { return ident; }
+  const std::string as_string () const { return ident; }
 
   bool empty () const { return ident.empty (); }
 
@@ -409,7 +410,7 @@ public:
 };
 
 // A simple path without generic or type arguments
-class SimplePath
+class SimplePath : public ProcMacroInvocable
 {
   bool opening_scope_resolution;
   std::vector<SimplePathSegment> segments;
@@ -435,15 +436,15 @@ public:
   // Returns whether the SimplePath is empty, i.e. has path segments.
   bool is_empty () const { return segments.empty (); }
 
-  std::string as_string () const;
+  const std::string as_string () const override;
 
   bool has_opening_scope_resolution () const
   {
     return opening_scope_resolution;
   }
 
-  location_t get_locus () const { return locus; }
-  NodeId get_node_id () const { return node_id; }
+  location_t get_locus () const override { return locus; }
+  NodeId get_node_id () const override { return node_id; }
 
   // does this need visitor if not polymorphic? probably not
 
diff --git a/gcc/rust/ast/rust-macro.h b/gcc/rust/ast/rust-macro.h
index db8cf1e..78941f8 100644
--- a/gcc/rust/ast/rust-macro.h
+++ b/gcc/rust/ast/rust-macro.h
@@ -838,6 +838,8 @@ public:
     return path;
   }
 
+  SimplePath &get_path () { return path; }
+
   location_t get_locus () const override { return path.get_locus (); }
 
   bool check_cfg_predicate (const Session &session) const override;
@@ -935,7 +937,7 @@ public:
 
   void accept_vis (ASTVisitor &vis) override;
 
-  Identifier get_ident () const { return ident; }
+  Identifier &get_ident () { return ident; }
 
   location_t get_locus () const override { return ident_locus; }
 
diff --git a/gcc/rust/ast/rust-path.h b/gcc/rust/ast/rust-path.h
index d70789c..12326a3 100644
--- a/gcc/rust/ast/rust-path.h
+++ b/gcc/rust/ast/rust-path.h
@@ -242,7 +242,7 @@ public:
     return type;
   }
 
-  const std::string &get_path () const
+  const std::string get_path () const
   {
     rust_assert (kind == Kind::Either);
 
diff --git a/gcc/rust/expand/rust-expand-visitor.cc b/gcc/rust/expand/rust-expand-visitor.cc
index c4b3791..3fa0b5f 100644
--- a/gcc/rust/expand/rust-expand-visitor.cc
+++ b/gcc/rust/expand/rust-expand-visitor.cc
@@ -57,43 +57,66 @@ ExpandVisitor::go (AST::Crate &crate)
  *
  * @param attrs The attributes on the item to derive
  */
-static std::vector<std::string>
+static std::vector<std::unique_ptr<ProcMacroInvocable>>
 get_traits_to_derive (AST::Attribute &attr)
 {
-  std::vector<std::string> to_derive;
-
+  std::vector<std::unique_ptr<ProcMacroInvocable>> result;
   auto &input = attr.get_attr_input ();
   switch (input.get_attr_input_type ())
     {
-      // isn't there a better way to do this?? like parse it or
-      // something idk. some function I'm not thinking of?
-      case AST::AttrInput::TOKEN_TREE: {
-	auto &tokens
-	  = static_cast<AST::DelimTokenTree &> (input).get_token_trees ();
-
-	// erase the delimiters
-	rust_assert (tokens.size () >= 2);
-	tokens.erase (tokens.begin ());
-	tokens.pop_back ();
-
-	for (auto &token : tokens)
+      case AST::AttrInput::META_ITEM: {
+	auto meta = static_cast<AST::AttrInputMetaItemContainer &> (input);
+	for (auto &current : meta.get_items ())
 	  {
-	    // skip commas, as they are part of the token stream
-	    if (token->as_string () == ",")
-	      continue;
-
-	    to_derive.emplace_back (token->as_string ());
+	    // HACK: Find a better way to achieve the downcast.
+	    switch (current->get_kind ())
+	      {
+		case AST::MetaItemInner::Kind::MetaItem: {
+		  // Let raw pointer go out of scope without freeing, it doesn't
+		  // own the data anyway
+		  auto meta_item
+		    = static_cast<AST::MetaItem *> (current.get ());
+		  switch (meta_item->get_item_kind ())
+		    {
+		      case AST::MetaItem::ItemKind::Path: {
+			auto path
+			  = static_cast<AST::MetaItemPath *> (meta_item);
+			result.push_back (Rust::make_unique<AST::SimplePath> (
+			  path->get_path ()));
+		      }
+		      break;
+		      case AST::MetaItem::ItemKind::Word: {
+			auto word = static_cast<AST::MetaWord *> (meta_item);
+			result.push_back (
+			  Rust::make_unique<Identifier> (word->get_ident ()));
+		      }
+		      break;
+		    case AST::MetaItem::ItemKind::ListPaths:
+		    case AST::MetaItem::ItemKind::NameValueStr:
+		    case AST::MetaItem::ItemKind::PathLit:
+		    case AST::MetaItem::ItemKind::Seq:
+		    case AST::MetaItem::ItemKind::ListNameValueStr:
+		    default:
+		      gcc_unreachable ();
+		      break;
+		    }
+		}
+		break;
+	      case AST::MetaItemInner::Kind::LitExpr:
+	      default:
+		gcc_unreachable ();
+		break;
+	      }
 	  }
-	break;
       }
+      break;
+    case AST::AttrInput::TOKEN_TREE:
     case AST::AttrInput::LITERAL:
-    case AST::AttrInput::META_ITEM:
     case AST::AttrInput::MACRO:
       rust_unreachable ();
       break;
     }
-
-  return to_derive;
+  return result;
 }
 
 static std::unique_ptr<AST::Item>
@@ -104,7 +127,7 @@ builtin_derive_item (AST::Item &item, const AST::Attribute &derive,
 }
 
 static std::vector<std::unique_ptr<AST::Item>>
-derive_item (AST::Item &item, const std::string &to_derive,
+derive_item (AST::Item &item, ProcMacroInvocable &to_derive,
 	     MacroExpander &expander)
 {
   std::vector<std::unique_ptr<AST::Item>> result;
@@ -127,7 +150,7 @@ derive_item (AST::Item &item, const std::string &to_derive,
 }
 
 static std::vector<std::unique_ptr<AST::Item>>
-expand_item_attribute (AST::Item &item, AST::SimplePath &name,
+expand_item_attribute (AST::Item &item, ProcMacroInvocable &name,
 		       MacroExpander &expander)
 {
   std::vector<std::unique_ptr<AST::Item>> result;
@@ -232,13 +255,14 @@ ExpandVisitor::expand_inner_items (
 
 	      if (is_derive (current))
 		{
+		  current.parse_attr_to_meta_item ();
 		  attr_it = attrs.erase (attr_it);
 		  // Get traits to derive in the current attribute
 		  auto traits_to_derive = get_traits_to_derive (current);
 		  for (auto &to_derive : traits_to_derive)
 		    {
-		      auto maybe_builtin
-			= MacroBuiltin::builtins.lookup (to_derive);
+		      auto maybe_builtin = MacroBuiltin::builtins.lookup (
+			to_derive->as_string ());
 		      if (MacroBuiltin::builtins.is_iter_ok (maybe_builtin))
 			{
 			  auto new_item
@@ -251,7 +275,7 @@ ExpandVisitor::expand_inner_items (
 		      else
 			{
 			  auto new_items
-			    = derive_item (*item, to_derive, expander);
+			    = derive_item (*item, *to_derive, expander);
 			  std::move (new_items.begin (), new_items.end (),
 				     std::inserter (items, it));
 			}
@@ -323,8 +347,8 @@ ExpandVisitor::expand_inner_stmts (AST::BlockExpr &expr)
 		  auto traits_to_derive = get_traits_to_derive (current);
 		  for (auto &to_derive : traits_to_derive)
 		    {
-		      auto maybe_builtin
-			= MacroBuiltin::builtins.lookup (to_derive);
+		      auto maybe_builtin = MacroBuiltin::builtins.lookup (
+			to_derive->as_string ());
 		      if (MacroBuiltin::builtins.is_iter_ok (maybe_builtin))
 			{
 			  auto new_item
@@ -337,7 +361,7 @@ ExpandVisitor::expand_inner_stmts (AST::BlockExpr &expr)
 		      else
 			{
 			  auto new_items
-			    = derive_item (item, to_derive, expander);
+			    = derive_item (item, *to_derive, expander);
 			  std::move (new_items.begin (), new_items.end (),
 				     std::inserter (stmts, it));
 			}
diff --git a/gcc/rust/expand/rust-macro-expand.cc b/gcc/rust/expand/rust-macro-expand.cc
index ac57e83..28868af 100644
--- a/gcc/rust/expand/rust-macro-expand.cc
+++ b/gcc/rust/expand/rust-macro-expand.cc
@@ -1093,50 +1093,6 @@ MacroExpander::transcribe_rule (
   return fragment;
 }
 
-// TODO: Move to early name resolver ?
-void
-MacroExpander::import_proc_macros (std::string extern_crate)
-{
-  auto path = session.extern_crates.find (extern_crate);
-  if (path == session.extern_crates.end ())
-    {
-      // Extern crate path is not available.
-      // FIXME: Emit error
-      rust_error_at (UNDEF_LOCATION, "Cannot find requested proc macro crate");
-      rust_unreachable ();
-    }
-  auto macros = load_macros (path->second);
-
-  std::string prefix = extern_crate + "::";
-  for (auto &macro : macros)
-    {
-      switch (macro.tag)
-	{
-	case ProcMacro::CUSTOM_DERIVE:
-	  rust_debug ("Found one derive proc macro.");
-	  mappings->insert_derive_proc_macro (
-	    std::make_pair (extern_crate,
-			    macro.payload.custom_derive.trait_name),
-	    macro.payload.custom_derive);
-	  break;
-	case ProcMacro::ATTR:
-	  rust_debug ("Found one attribute proc macro.");
-	  mappings->insert_attribute_proc_macro (
-	    std::make_pair (extern_crate, macro.payload.attribute.name),
-	    macro.payload.attribute);
-	  break;
-	case ProcMacro::BANG:
-	  rust_debug ("Found one bang proc macro.");
-	  mappings->insert_bang_proc_macro (
-	    std::make_pair (extern_crate, macro.payload.bang.name),
-	    macro.payload.bang);
-	  break;
-	default:
-	  rust_unreachable ();
-	}
-    }
-}
-
 AST::Fragment
 MacroExpander::parse_proc_macro_output (ProcMacro::TokenStream ts)
 {
diff --git a/gcc/rust/expand/rust-macro-expand.h b/gcc/rust/expand/rust-macro-expand.h
index 30d2970..f83de95 100644
--- a/gcc/rust/expand/rust-macro-expand.h
+++ b/gcc/rust/expand/rust-macro-expand.h
@@ -407,27 +407,13 @@ struct MacroExpander
   void import_proc_macros (std::string extern_crate);
 
   template <typename T>
-  AST::Fragment expand_derive_proc_macro (T &item,
-					  const std::string &trait_name)
+  AST::Fragment expand_derive_proc_macro (T &item, ProcMacroInvocable &path)
   {
     ProcMacro::CustomDerive macro;
-
-    // FIXME: Resolve crate name
-    std::string crate = "";
-    std::string name = trait_name;
-
-    if (!mappings->lookup_derive_proc_macro (std::make_pair (crate, name),
-					     macro))
+    if (!mappings->lookup_derive_proc_macro_invocation (path, macro))
       {
-	// FIXME: Resolve this path segment instead of taking it directly.
-	import_proc_macros (crate);
-	if (!mappings->lookup_derive_proc_macro (std::make_pair (crate, name),
-						 macro))
-	  {
-	    rust_error_at (UNDEF_LOCATION, "procedural macro %s not found",
-			   name.c_str ());
-	    rust_assert (false);
-	  }
+	rust_error_at (path.get_locus (), "Macro not found");
+	return AST::Fragment::create_error ();
       }
 
     AST::TokenCollector collector;
@@ -441,24 +427,14 @@ struct MacroExpander
   }
 
   template <typename T>
-  AST::Fragment expand_bang_proc_macro (T &item, AST::SimplePath &path)
+  AST::Fragment expand_bang_proc_macro (T &item,
+					AST::MacroInvocation &invocation)
   {
     ProcMacro::Bang macro;
-
-    std::string crate = path.get_segments ()[0].get_segment_name ();
-    std::string name = path.get_segments ()[1].get_segment_name ();
-    if (!mappings->lookup_bang_proc_macro (std::make_pair (crate, name), macro))
+    if (!mappings->lookup_bang_proc_macro_invocation (invocation, macro))
       {
-	// FIXME: Resolve this path segment instead of taking it directly.
-	import_proc_macros (crate);
-
-	if (!mappings->lookup_bang_proc_macro (std::make_pair (crate, name),
-					       macro))
-	  {
-	    rust_error_at (UNDEF_LOCATION, "procedural macro %s not found",
-			   name.c_str ());
-	    rust_assert (false);
-	  }
+	rust_error_at (invocation.get_locus (), "Macro not found");
+	return AST::Fragment::create_error ();
       }
 
     AST::TokenCollector collector;
@@ -472,25 +448,13 @@ struct MacroExpander
   }
 
   template <typename T>
-  AST::Fragment expand_attribute_proc_macro (T &item, AST::SimplePath &path)
+  AST::Fragment expand_attribute_proc_macro (T &item, ProcMacroInvocable &path)
   {
     ProcMacro::Attribute macro;
-
-    std::string crate = path.get_segments ()[0].get_segment_name ();
-    std::string name = path.get_segments ()[1].get_segment_name ();
-    if (!mappings->lookup_attribute_proc_macro (std::make_pair (crate, name),
-						macro))
+    if (!mappings->lookup_attribute_proc_macro_invocation (path, macro))
       {
-	// FIXME: Resolve this path segment instead of taking it directly.
-	import_proc_macros (crate);
-	if (!mappings->lookup_attribute_proc_macro (std::make_pair (crate,
-								    name),
-						    macro))
-	  {
-	    rust_error_at (UNDEF_LOCATION, "procedural macro %s not found",
-			   name.c_str ());
-	    rust_assert (false);
-	  }
+	rust_error_at (path.get_locus (), "Macro not found");
+	return AST::Fragment::create_error ();
       }
 
     AST::TokenCollector collector;
diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index caf44a2..aeb813a 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -1007,40 +1007,39 @@ Mappings::lookup_attribute_proc_macros (
 }
 
 void
-Mappings::insert_derive_proc_macro (
-  std::pair<std::string, std::string> hierarchy, ProcMacro::CustomDerive macro)
+Mappings::insert_derive_proc_macro_def (NodeId id,
+					ProcMacro::CustomDerive macro)
 {
-  auto it = procmacroDeriveMappings.find (hierarchy);
+  auto it = procmacroDeriveMappings.find (id);
   rust_assert (it == procmacroDeriveMappings.end ());
 
-  procmacroDeriveMappings[hierarchy] = macro;
+  procmacroDeriveMappings[id] = macro;
 }
 
 void
-Mappings::insert_bang_proc_macro (std::pair<std::string, std::string> hierarchy,
-				  ProcMacro::Bang macro)
+Mappings::insert_bang_proc_macro_def (NodeId id, ProcMacro::Bang macro)
 {
-  auto it = procmacroBangMappings.find (hierarchy);
+  auto it = procmacroBangMappings.find (id);
   rust_assert (it == procmacroBangMappings.end ());
 
-  procmacroBangMappings[hierarchy] = macro;
+  procmacroBangMappings[id] = macro;
 }
 
 void
-Mappings::insert_attribute_proc_macro (
-  std::pair<std::string, std::string> hierarchy, ProcMacro::Attribute macro)
+Mappings::insert_attribute_proc_macro_def (NodeId id,
+					   ProcMacro::Attribute macro)
 {
-  auto it = procmacroAttributeMappings.find (hierarchy);
+  auto it = procmacroAttributeMappings.find (id);
   rust_assert (it == procmacroAttributeMappings.end ());
 
-  procmacroAttributeMappings[hierarchy] = macro;
+  procmacroAttributeMappings[id] = macro;
 }
 
 bool
-Mappings::lookup_derive_proc_macro (
-  std::pair<std::string, std::string> hierarchy, ProcMacro::CustomDerive &macro)
+Mappings::lookup_derive_proc_macro_def (NodeId id,
+					ProcMacro::CustomDerive &macro)
 {
-  auto it = procmacroDeriveMappings.find (hierarchy);
+  auto it = procmacroDeriveMappings.find (id);
   if (it == procmacroDeriveMappings.end ())
     return false;
 
@@ -1049,10 +1048,9 @@ Mappings::lookup_derive_proc_macro (
 }
 
 bool
-Mappings::lookup_bang_proc_macro (std::pair<std::string, std::string> hierarchy,
-				  ProcMacro::Bang &macro)
+Mappings::lookup_bang_proc_macro_def (NodeId id, ProcMacro::Bang &macro)
 {
-  auto it = procmacroBangMappings.find (hierarchy);
+  auto it = procmacroBangMappings.find (id);
   if (it == procmacroBangMappings.end ())
     return false;
 
@@ -1061,10 +1059,10 @@ Mappings::lookup_bang_proc_macro (std::pair<std::string, std::string> hierarchy,
 }
 
 bool
-Mappings::lookup_attribute_proc_macro (
-  std::pair<std::string, std::string> hierarchy, ProcMacro::Attribute &macro)
+Mappings::lookup_attribute_proc_macro_def (NodeId id,
+					   ProcMacro::Attribute &macro)
 {
-  auto it = procmacroAttributeMappings.find (hierarchy);
+  auto it = procmacroAttributeMappings.find (id);
   if (it == procmacroAttributeMappings.end ())
     return false;
 
@@ -1073,6 +1071,72 @@ Mappings::lookup_attribute_proc_macro (
 }
 
 void
+Mappings::insert_derive_proc_macro_invocation (Rust::ProcMacroInvocable &invoc,
+					       ProcMacro::CustomDerive def)
+{
+  auto it = procmacroDeriveInvocations.find (invoc.get_node_id ());
+  rust_assert (it == procmacroDeriveInvocations.end ());
+
+  procmacroDeriveInvocations[invoc.get_node_id ()] = def;
+}
+
+bool
+Mappings::lookup_derive_proc_macro_invocation (Rust::ProcMacroInvocable &invoc,
+					       ProcMacro::CustomDerive &def)
+{
+  auto it = procmacroDeriveInvocations.find (invoc.get_node_id ());
+  if (it == procmacroDeriveInvocations.end ())
+    return false;
+
+  def = it->second;
+  return true;
+}
+
+void
+Mappings::insert_bang_proc_macro_invocation (AST::MacroInvocation &invoc,
+					     ProcMacro::Bang def)
+{
+  auto it = procmacroBangInvocations.find (invoc.get_macro_node_id ());
+  rust_assert (it == procmacroBangInvocations.end ());
+
+  procmacroBangInvocations[invoc.get_macro_node_id ()] = def;
+}
+
+bool
+Mappings::lookup_bang_proc_macro_invocation (AST::MacroInvocation &invoc,
+					     ProcMacro::Bang &def)
+{
+  auto it = procmacroBangInvocations.find (invoc.get_macro_node_id ());
+  if (it == procmacroBangInvocations.end ())
+    return false;
+
+  def = it->second;
+  return true;
+}
+
+void
+Mappings::insert_attribute_proc_macro_invocation (
+  Rust::ProcMacroInvocable &invoc, ProcMacro::Attribute def)
+{
+  auto it = procmacroAttributeInvocations.find (invoc.get_node_id ());
+  rust_assert (it == procmacroAttributeInvocations.end ());
+
+  procmacroAttributeInvocations[invoc.get_node_id ()] = def;
+}
+
+bool
+Mappings::lookup_attribute_proc_macro_invocation (
+  Rust::ProcMacroInvocable &invoc, ProcMacro::Attribute &def)
+{
+  auto it = procmacroAttributeInvocations.find (invoc.get_node_id ());
+  if (it == procmacroAttributeInvocations.end ())
+    return false;
+
+  def = it->second;
+  return true;
+}
+
+void
 Mappings::insert_visibility (NodeId id, Privacy::ModuleVisibility visibility)
 {
   visibility_map.insert ({id, visibility});
diff --git a/gcc/rust/util/rust-hir-map.h b/gcc/rust/util/rust-hir-map.h
index a47898b..293a6d1 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -28,6 +28,7 @@
 #include "rust-hir-full-decls.h"
 #include "rust-lang-item.h"
 #include "rust-privacy-common.h"
+#include "rust-proc-macro-invocation.h"
 #include "libproc_macro/proc_macro.h"
 
 namespace Rust {
@@ -297,21 +298,27 @@ public:
   bool lookup_attribute_proc_macros (CrateNum num,
 				     std::vector<ProcMacro::Attribute> &macros);
 
-  void insert_derive_proc_macro (std::pair<std::string, std::string> hierachy,
-				 ProcMacro::CustomDerive macro);
-  void insert_bang_proc_macro (std::pair<std::string, std::string> hierachy,
-			       ProcMacro::Bang macro);
-  void
-  insert_attribute_proc_macro (std::pair<std::string, std::string> hierachy,
-			       ProcMacro::Attribute macro);
-
-  bool lookup_derive_proc_macro (std::pair<std::string, std::string> hierachy,
-				 ProcMacro::CustomDerive &macro);
-  bool lookup_bang_proc_macro (std::pair<std::string, std::string> hierachy,
-			       ProcMacro::Bang &macro);
-  bool
-  lookup_attribute_proc_macro (std::pair<std::string, std::string> hierachy,
-			       ProcMacro::Attribute &macro);
+  void insert_derive_proc_macro_def (NodeId id, ProcMacro::CustomDerive macro);
+  void insert_bang_proc_macro_def (NodeId id, ProcMacro::Bang macro);
+  void insert_attribute_proc_macro_def (NodeId id, ProcMacro::Attribute macro);
+
+  bool lookup_derive_proc_macro_def (NodeId id, ProcMacro::CustomDerive &macro);
+  bool lookup_bang_proc_macro_def (NodeId id, ProcMacro::Bang &macro);
+  bool lookup_attribute_proc_macro_def (NodeId id, ProcMacro::Attribute &macro);
+
+  void insert_derive_proc_macro_invocation (Rust::ProcMacroInvocable &invoc,
+					    ProcMacro::CustomDerive def);
+
+  bool lookup_derive_proc_macro_invocation (Rust::ProcMacroInvocable &invoc,
+					    ProcMacro::CustomDerive &def);
+  void insert_bang_proc_macro_invocation (AST::MacroInvocation &invoc,
+					  ProcMacro::Bang def);
+  bool lookup_bang_proc_macro_invocation (AST::MacroInvocation &invoc_id,
+					  ProcMacro::Bang &def);
+  void insert_attribute_proc_macro_invocation (Rust::ProcMacroInvocable &invoc,
+					       ProcMacro::Attribute def);
+  bool lookup_attribute_proc_macro_invocation (Rust::ProcMacroInvocable &invoc,
+					       ProcMacro::Attribute &def);
 
   void insert_visibility (NodeId id, Privacy::ModuleVisibility visibility);
   bool lookup_visibility (NodeId id, Privacy::ModuleVisibility &def);
@@ -392,20 +399,16 @@ private:
   // Procedural macros
   std::map<CrateNum, std::vector<ProcMacro::CustomDerive>>
     procmacrosDeriveMappings;
-
   std::map<CrateNum, std::vector<ProcMacro::Bang>> procmacrosBangMappings;
-
   std::map<CrateNum, std::vector<ProcMacro::Attribute>>
     procmacrosAttributeMappings;
 
-  std::map<std::pair<std::string, std::string>, ProcMacro::CustomDerive>
-    procmacroDeriveMappings;
-
-  std::map<std::pair<std::string, std::string>, ProcMacro::Bang>
-    procmacroBangMappings;
-
-  std::map<std::pair<std::string, std::string>, ProcMacro::Attribute>
-    procmacroAttributeMappings;
+  std::map<NodeId, ProcMacro::CustomDerive> procmacroDeriveMappings;
+  std::map<NodeId, ProcMacro::Bang> procmacroBangMappings;
+  std::map<NodeId, ProcMacro::Attribute> procmacroAttributeMappings;
+  std::map<NodeId, ProcMacro::CustomDerive> procmacroDeriveInvocations;
+  std::map<NodeId, ProcMacro::Bang> procmacroBangInvocations;
+  std::map<NodeId, ProcMacro::Attribute> procmacroAttributeInvocations;
 
   // crate names
   std::map<CrateNum, std::string> crate_names;
diff --git a/gcc/rust/util/rust-proc-macro-invocation.h b/gcc/rust/util/rust-proc-macro-invocation.h
new file mode 100644
index 0000000..b45e013
--- /dev/null
+++ b/gcc/rust/util/rust-proc-macro-invocation.h
@@ -0,0 +1,21 @@
+#ifndef RUST_PROC_MACRO_INVOCATION_H
+#define RUST_PROC_MACRO_INVOCATION_H
+
+#include "rust-mapping-common.h"
+#include "rust-location.h"
+
+namespace Rust {
+
+class ProcMacroInvocable
+{
+public:
+  virtual NodeId get_node_id () const = 0;
+  virtual const std::string as_string () const = 0;
+  virtual Location get_locus () const = 0;
+
+  virtual ~ProcMacroInvocable () {}
+};
+
+} // namespace Rust
+
+#endif /* ! RUST_PROC_MACRO_INVOCATION_H*/