Closes #15030: Make importlib.abc.PyPycLoader respect the new .pyc

file size header field.

Thanks to Marc Abramowitz and Ronan Lamy for helping out with various
parts of the patch.

2 files changed, 13 insertions, 3 deletions

diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py
index c171da3..8d65907 100644
--- a/Lib/importlib/abc.py
+++ b/Lib/importlib/abc.py
@@ -282,7 +282,12 @@ class PyPycLoader(PyLoader):
                 if len(raw_timestamp) < 4:
                     raise EOFError("bad timestamp in {}".format(fullname))
                 pyc_timestamp = _bootstrap._r_long(raw_timestamp)
-                bytecode = data[8:]
+                raw_source_size = data[8:12]
+                if len(raw_source_size) != 4:
+                    raise EOFError("bad file size in {}".format(fullname))
+                # Source size is unused as the ABC does not provide a way to
+                # get the size of the source ahead of reading it.
+                bytecode = data[12:]
                 # Verify that the magic number is valid.
                 if imp.get_magic() != magic:
                     raise ImportError(
@@ -318,6 +323,7 @@ class PyPycLoader(PyLoader):
         if not sys.dont_write_bytecode:
             data = bytearray(imp.get_magic())
             data.extend(_bootstrap._w_long(source_timestamp))
+            data.extend(_bootstrap._w_long(len(source) & 0xFFFFFFFF))
             data.extend(marshal.dumps(code_object))
             self.write_bytecode(fullname, data)
         return code_object
diff --git a/Lib/importlib/test/source/test_abc_loader.py b/Lib/importlib/test/source/test_abc_loader.py
index 27babb9..afcaad0 100644
--- a/Lib/importlib/test/source/test_abc_loader.py
+++ b/Lib/importlib/test/source/test_abc_loader.py
@@ -148,11 +148,12 @@ class PyPycLoaderMock(abc.PyPycLoader, PyLoaderMock):
             self.bytecode_to_path[name] = data['path']
             magic = data.get('magic', imp.get_magic())
             mtime = importlib._w_long(data.get('mtime', self.default_mtime))
+            source_size = importlib._w_long(len(self.source) & 0xFFFFFFFF)
             if 'bc' in data:
                 bc = data['bc']
             else:
                 bc = self.compile_bc(name)
-            self.module_bytecode[name] = magic + mtime + bc
+            self.module_bytecode[name] = magic + mtime + source_size + bc
 
     def compile_bc(self, name):
         source_path = self.module_paths.get(name, '<test>') or '<test>'
@@ -344,7 +345,10 @@ class PyPycLoaderTests(PyLoaderTests):
         self.assertEqual(magic, imp.get_magic())
         mtime = importlib._r_long(mock.module_bytecode[name][4:8])
         self.assertEqual(mtime, 1)
-        bc = mock.module_bytecode[name][8:]
+        source_size = mock.module_bytecode[name][8:12]
+        self.assertEqual(len(mock.source) & 0xFFFFFFFF,
+                         importlib._r_long(source_size))
+        bc = mock.module_bytecode[name][12:]
         self.assertEqual(bc, mock.compile_bc(name))
 
     def test_module(self):