fix: Fix defs+refs for globals.

scip_indexer/SCIPIndexer.cc

@@ -553,6 +553,14 @@ class AliasMap final {
                 if (sym == core::Symbols::Magic_undeclaredFieldStub()) {
                     ENFORCE(!bind.loc.empty());
                     ENFORCE(klass.isClassOrModule());
+                    auto fieldName = instr->name.shortName(gs);
+                    if (!fieldName.empty() && fieldName[0] == '$') {
+                        auto klass = core::Symbols::rootSingleton();
+                        this->map.insert( // no trim(...) because globals can't have a :: prefix
+                            {bind.bind.variable,
+                             {GenericSymbolRef::undeclaredField(klass, instr->name, bind.bind.type), bind.loc, false}});
+                        continue;
+                    }
                     auto result = findUnresolvedFieldTransitive(ctx, ctx.locAt(bind.loc), klass.asClassOrModuleRef(),
                                                                 instr->name);
                     if (absl::holds_alternative<core::ClassOrModuleRef>(result)) {

test/scip/testdata/globals.rb

@@ -0,0 +1,18 @@
+# typed: true
+
+$aa = 0
+
+def f
+  $aa = 10
+  $bb = $aa
+  $aa = $bb
+  return
+end
+
+class C
+  def g
+    $c = $bb
+  end
+end
+
+puts $c

test/scip/testdata/globals.snapshot.rb

@@ -0,0 +1,32 @@
+ # typed: true
+
+ $aa = 0
+#^^^ definition [..] `<Class:<root>>`#$aa.
+
+ def f
+#    ^ definition [..] Object#f().
+   $aa = 10
+#  ^^^ definition [..] `<Class:<root>>`#$aa.
+   $bb = $aa
+#  ^^^ definition [..] `<Class:<root>>`#$bb.
+#        ^^^ reference [..] `<Class:<root>>`#$aa.
+   $aa = $bb
+#  ^^^ reference (write) [..] `<Class:<root>>`#$aa.
+#        ^^^ reference [..] `<Class:<root>>`#$bb.
+   return
+ end
+
+ class C
+#      ^ definition [..] C#
+   def g
+#      ^ definition [..] C#g().
+     $c = $bb
+#    ^^ definition [..] `<Class:<root>>`#$c.
+#    ^^^^^^^^ reference [..] `<Class:<root>>`#$c.
+#         ^^^ reference [..] `<Class:<root>>`#$bb.
+   end
+ end
+
+ puts $c
+#^^^^ reference [..] Kernel#puts().
+#     ^^ reference [..] `<Class:<root>>`#$c.