- reverts "- attempting to reduce branch coverage overhead under Pyth…

…on 3.12;",

  as that didn't reduce overhead.  This reverts commit 7ce89fb.

src/slipcover/branch.py

@@ -26,22 +26,18 @@ def __init__(self):
             pass
 
         def _mark_branch(self, from_line: int, to_line: int) -> List[ast.stmt]:
+            mark = ast.Assign([ast.Name(BRANCH_NAME, ast.Store())],
+                               ast.Tuple([ast.Constant(from_line), ast.Constant(to_line)], ast.Load()))
 
             if sys.version_info[0:2] == (3,12):
-                mark = ast.Assign([ast.Name(BRANCH_NAME, ast.Store())], ast.Constant(0))
                 for node in ast.walk(mark):
                     node.lineno = node.end_lineno = encode_branch(from_line, to_line)
-
+            elif sys.version_info[0:2] == (3,11):
+                for node in ast.walk(mark):
+                    node.lineno = 0 # we ignore line 0, so this avoids generating extra line probes
             else:
-                mark = ast.Assign([ast.Name(BRANCH_NAME, ast.Store())],
-                                   ast.Tuple([ast.Constant(from_line), ast.Constant(to_line)], ast.Load()))
-
-                if sys.version_info[0:2] == (3,11):
-                    for node in ast.walk(mark):
-                        node.lineno = 0 # we ignore line 0, so this avoids generating extra line probes
-                else:
-                    for node in ast.walk(mark):
-                        node.lineno = from_line
+                for node in ast.walk(mark):
+                    node.lineno = from_line
 
             return [mark]
 

tests/test_branch.py

@@ -31,10 +31,7 @@ def get_branches(code):
 
         elif const is not None:
             if inst.opname in ('STORE_NAME', 'STORE_GLOBAL') and inst.argval == br.BRANCH_NAME:
-                if PYTHON_VERSION >= (3,12) and br.is_branch(inst.positions.lineno):
-                    branches.append(br.decode_branch(inst.positions.lineno))
-                else:
-                    branches.append(const)
+                branches.append(const)
 
             const = None
 
@@ -50,16 +47,10 @@ def __init__(self):
         def visit_Assign(self, node: ast.Assign) -> ast.Assign:
             if node.targets and isinstance(node.targets[0], ast.Name) \
                and node.targets[0].id == br.BRANCH_NAME:
-                if PYTHON_VERSION >= (3,12) and br.is_branch(node.lineno):
-                    branch = br.decode_branch(node.lineno)
-                    value = ast.Tuple([ast.Constant(branch[0]), ast.Constant(branch[1])], ast.Load())
-                    value.lineno, value.end_lineno = node.lineno, node.end_lineno
-                else:
-                    value = node.value
                 return ast.AugAssign(
                         target=node.targets[0],
                         op=ast.Add(),
-                        value=ast.List(elts=[value], ctx=ast.Load()),
+                        value=ast.List(elts=[node.value], ctx=ast.Load()),
                         ctx=ast.Load())
 
             return node