Merge pull request #5138 from crystal-lang/bug/block-arg-underscore

asterite · web-flow · commit a6ddeb3daf14 · 2017-10-17T15:14:24.000-03:00
Codegen: don't assign yield exp to underscore block arguments
diff --git a/spec/compiler/codegen/block_spec.cr b/spec/compiler/codegen/block_spec.cr
@@ -1509,4 +1509,13 @@ describe "Code gen: block" do
       a + b
       )).to_i.should eq(3)
   end
+
+  it "codegens block with repeated underscore and different types (#4711)" do
+    codegen(%(
+      def foo
+        yield('0', 0)
+      end
+      foo{|_, _| }
+      ))
+  end
 end
diff --git a/src/compiler/crystal/codegen/codegen.cr b/src/compiler/crystal/codegen/codegen.cr
@@ -1407,7 +1407,7 @@ module Crystal
             exp_value = exp_values.first[0]
             exp_type.tuple_types.each_with_index do |tuple_type, i|
               arg = block.args[i]?
-              if arg
+              if arg && arg.name != "_"
                 t_type = tuple_type
                 t_value = codegen_tuple_indexer(exp_type, exp_value, i)
                 block_var = block_context.vars[arg.name]
@@ -1416,7 +1416,7 @@ module Crystal
             end
           else
             exp_values.each_with_index do |(exp_value, exp_type), i|
-              if arg = block.args[i]?
+              if (arg = block.args[i]?) && arg.name != "_"
                 block_var = block_context.vars[arg.name]
                 assign block_var.pointer, block_var.type, exp_type, exp_value
               end
