Merge #1580

1580: Add early name resolver r=CohenArthur a=CohenArthur

This addresses our issue with name resolution (#1576) not acting on macros early enough but does not fix it yet.

This name resolver performs the same macro name resolution as what was previously done by the AttrVisitor visitor and macro expander.

It also resolves macro expressions in builtin-macros properly, as well as expanded AST nodes when necessary.

Co-authored-by: Arthur Cohen <arthur.cohen@embecosm.com>

1 files changed, 8 insertions, 22 deletions

diff --git a/gcc/rust/expand/rust-macro-expand.cc b/gcc/rust/expand/rust-macro-expand.cc
index e7a7b84..96b74da 100644
--- a/gcc/rust/expand/rust-macro-expand.cc
+++ b/gcc/rust/expand/rust-macro-expand.cc
@@ -23,6 +23,7 @@
 #include "rust-diagnostics.h"
 #include "rust-parse.h"
 #include "rust-attribute-visitor.h"
+#include "rust-early-name-resolver.h"
 
 namespace Rust {
 AST::ASTFragment
@@ -138,32 +139,17 @@ MacroExpander::expand_invoc (AST::MacroInvocation &invoc, bool has_semicolon)
   //      - else is unreachable
   //  - derive container macro - unreachable
 
-  // lookup the rules for this macro
-  NodeId resolved_node = UNKNOWN_NODEID;
-  NodeId source_node = UNKNOWN_NODEID;
-  if (has_semicolon)
-    source_node = invoc.get_macro_node_id ();
-  else
-    source_node = invoc.get_pattern_node_id ();
-  auto seg
-    = Resolver::CanonicalPath::new_seg (source_node,
-					invoc_data.get_path ().as_string ());
-
-  bool found = resolver->get_macro_scope ().lookup (seg, &resolved_node);
-  if (!found)
-    {
-      rust_error_at (invoc.get_locus (), "unknown macro: [%s]",
-		     seg.get ().c_str ());
-      return;
-    }
+  auto fragment = AST::ASTFragment::create_error ();
+  invoc_data.set_expander (this);
 
   // lookup the rules
   AST::MacroRulesDefinition *rules_def = nullptr;
-  bool ok = mappings->lookup_macro_def (resolved_node, &rules_def);
-  rust_assert (ok);
+  bool ok = mappings->lookup_macro_invocation (invoc, &rules_def);
 
-  auto fragment = AST::ASTFragment::create_error ();
-  invoc_data.set_expander (this);
+  // If there's no rule associated with the invocation, we can simply return
+  // early. The early name resolver will have already emitted an error.
+  if (!ok)
+    return;
 
   if (rules_def->is_builtin ())
     fragment