Error on TypeNode#instance_vars, #has_inner_pointers? macros in top-level scope

spec/compiler/macro/macro_methods_spec.cr

@@ -1785,9 +1785,30 @@ module Crystal
         end
       end
 
-      it "executes instance_vars" do
-        assert_macro("{{x.instance_vars.map &.stringify}}", %(["bytesize", "length", "c"])) do |program|
-          {x: TypeNode.new(program.string)}
+      describe "#instance_vars" do
+        it "executes instance_vars" do
+          assert_macro("{{x.instance_vars.map &.stringify}}", %(["bytesize", "length", "c"])) do |program|
+            {x: TypeNode.new(program.string)}
+          end
+        end
+
+        it "errors when called from top-level scope" do
+          assert_error <<-CRYSTAL, "`TypeNode#instance_vars` cannot be called in the top-level scope: instance vars are not yet initialized"
+            class Foo
+            end
+            {{ Foo.instance_vars }}
+          CRYSTAL
+        end
+
+        it "does not error when called from def scope" do
+          assert_type <<-CRYSTAL {|program| program.string }
+            module Moo
+            end
+            def moo
+              {{ Moo.instance_vars.stringify }}
+            end
+            moo
+          CRYSTAL
         end
       end
 
@@ -2485,6 +2506,25 @@ module Crystal
             {x: TypeNode.new(program.proc_of(program.void))}
           end
         end
+
+        it "errors when called from top-level scope" do
+          assert_error <<-CRYSTAL, "`TypeNode#has_inner_pointers?` cannot be called in the top-level scope: instance vars are not yet initialized"
+            class Foo
+            end
+            {{ Foo.has_inner_pointers? }}
+          CRYSTAL
+        end
+
+        it "does not error when called from def scope" do
+          assert_type <<-CRYSTAL {|program| program.bool }
+            module Moo
+            end
+            def moo
+              {{ Moo.has_inner_pointers? }}
+            end
+            moo
+          CRYSTAL
+        end
       end
     end
 

spec/spec_helper.cr

@@ -208,6 +208,7 @@ end
 def prepare_macro_call(macro_body, flags = nil, &)
   program = new_program
   program.flags.concat(flags.split) if flags
+  program.top_level_semantic_complete = true
   args = yield program
 
   macro_params = args.try &.keys.join(", ")

src/compiler/crystal/macros/methods.cr

@@ -1859,7 +1859,7 @@ module Crystal
       when "type_vars"
         interpret_check_args { TypeNode.type_vars(type) }
       when "instance_vars"
-        interpret_check_args { TypeNode.instance_vars(type) }
+        interpret_check_args { TypeNode.instance_vars(type, name_loc) }
       when "class_vars"
         interpret_check_args { TypeNode.class_vars(type) }
       when "ancestors"
@@ -2021,7 +2021,7 @@ module Crystal
           end
         end
       when "has_inner_pointers?"
-        interpret_check_args { BoolLiteral.new(type.has_inner_pointers?) }
+        interpret_check_args { TypeNode.has_inner_pointers?(type, name_loc) }
       else
         super
       end
@@ -2077,8 +2077,15 @@ module Crystal
       end
     end
 
-    def self.instance_vars(type)
+    def self.instance_vars(type, name_loc)
       if type.is_a?(InstanceVarContainer)
+        unless type.program.top_level_semantic_complete?
+          if name_loc
+            raise Crystal::TypeException.new("`TypeNode#instance_vars` cannot be called in the top-level scope: instance vars are not yet initialized", name_loc)
+          else
+            raise Crystal::TypeException.new("`TypeNode#instance_vars` cannot be called in the top-level scope: instance vars are not yet initialized")
+          end
+        end
         ArrayLiteral.map(type.all_instance_vars) do |name, ivar|
           meta_var = MetaMacroVar.new(name[1..-1], ivar.type)
           meta_var.var = ivar
@@ -2090,6 +2097,18 @@ module Crystal
       end
     end
 
+    def self.has_inner_pointers?(type, name_loc)
+      unless type.program.top_level_semantic_complete?
+        if name_loc
+          raise Crystal::TypeException.new("`TypeNode#has_inner_pointers?` cannot be called in the top-level scope: instance vars are not yet initialized", name_loc)
+        else
+          raise Crystal::TypeException.new("`TypeNode#has_inner_pointers?` cannot be called in the top-level scope: instance vars are not yet initialized")
+        end
+      end
+
+      BoolLiteral.new(type.has_inner_pointers?)
+    end
+
     def self.class_vars(type)
       if type.is_a?(ClassVarContainer)
         ArrayLiteral.map(type.all_class_vars) do |name, ivar|

src/compiler/crystal/semantic.cr

@@ -87,6 +87,17 @@ class Crystal::Program
       end
     end
 
+    self.top_level_semantic_complete = true
+
     {node, processor}
   end
+
+  # This property indicates that the compiler has finished the top-level semantic
+  # stage.
+  # At this point, instance variables are declared and macros `#instance_vars`
+  # and `#has_internal_pointers?` provide meaningful information.
+  #
+  # FIXME: Introduce a more generic method to track progress of compiler stages
+  # (potential synergy with `ProcessTracker`?).
+  property? top_level_semantic_complete = false
 end