Nil var before loop

Signed-off-by: Stefan Marr <[email protected]>

Author: smarr

src/som/compiler/bc/method_generation_context.py

@@ -685,21 +685,23 @@ def inline_to_do(self, parser):
         block_literal_idx = self._bytecode[-1]
 
         to_be_inlined = self._literals[block_literal_idx]
+        to_be_inlined.merge_scope_into(self)
+
+        block_arg = to_be_inlined.get_argument(1, 0)
+        i_var_idx = self.get_inlined_local_idx(block_arg, 0)
 
         self._remove_last_bytecodes(1)  # remove push_block*
 
         self._is_currently_inlining_a_block = True
         emit_dup_second(self)
 
+        emit_nil_local(self, i_var_idx)
+
         loop_begin_idx = self.offset_of_next_instruction()
         jump_offset_idx_to_end = emit_jump_if_greater_with_dummy_offset(self)
 
         emit_dup(self)
 
-        to_be_inlined.merge_scope_into(self)
-
-        block_arg = to_be_inlined.get_argument(1, 0)
-        i_var_idx = self.get_inlined_local_idx(block_arg, 0)
         emit_pop_local(self, i_var_idx, 0)
 
         to_be_inlined.inline(self, False)

tests/test_bytecode_generation.py

@@ -1172,13 +1172,14 @@ def test_field_read_inlining(cgenc, mgenc):
 def test_inlining_of_to_do(mgenc):
     bytecodes = method_to_bytecodes(mgenc, "test = ( 1 to: 2 do: [:i | i ] )")
 
-    assert len(bytecodes) == 21
+    assert len(bytecodes) == 23
     check(
         bytecodes,
         [
             Bytecodes.push_1,
             Bytecodes.push_constant_0,
             Bytecodes.dup_second,  # stack: Top[1, 2, 1]
+            Bytecodes.nil_local,
             BC(Bytecodes.jump_if_greater, 17),  # consume only on jump
             Bytecodes.dup,
             BC(
@@ -1214,13 +1215,14 @@ def test_to_do_block_block_inlined_self(cgenc, mgenc):
         )""",
     )
 
-    assert len(bytecodes) == 25
+    assert len(bytecodes) == 27
     check(
         bytecodes,
         [
             Bytecodes.push_1,
             Bytecodes.push_constant_0,
             Bytecodes.dup_second,
+            Bytecodes.nil_local,
             BC(Bytecodes.jump_if_greater, 21),
             Bytecodes.dup,
             BC(Bytecodes.pop_local, 2, 0),