[gobject-introspection: 1/2] Add utils.rmtree() which waits and tries again if a file is still in use

[Christoph Reiter <creiter src gnome org>]

commit 7c6adf533001e214e63d284a1a00fa254b29d7b9
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Wed Jun 20 08:08:03 2018 +0200

    Add utils.rmtree() which waits and tries again if a file is still in use
    
    On Windows the dumper cleanup regularely fails because the created .exe
    is still in use by some process and shutil.rmtree() fails with:
    
    OSError: [WinError 145] The directory is not empty
    
    I'm not 100% sure what's the cause for this, but searching for similar issues
    suggests that it might be Windows Defender scanning the newly created .exe
    file and because it's so short lifed the scanning and deleting conflict.
    
    This adds a helper which tries a few times and waits a bit before giving up.
    A similar patch has been in MSYS2 for some time:
    
https://github.com/Alexpux/MINGW-packages/blob/d0c39af02a669e45272c713e912ee63b0dd94157/mingw-w64-gobject-introspection/0025-more-tolerant-rmtreeing.patch

 giscanner/dumper.py      |  5 ++---
 giscanner/gdumpparser.py |  3 +--
 giscanner/utils.py       | 25 +++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 5 deletions(-)
---
diff --git a/giscanner/dumper.py b/giscanner/dumper.py
index 06737188..d6956da2 100644
--- a/giscanner/dumper.py
+++ b/giscanner/dumper.py
@@ -28,7 +28,6 @@ import os
 import sys
 import shlex
 import subprocess
-import shutil
 import tempfile
 from distutils.errors import LinkError
 
@@ -171,14 +170,14 @@ class DumpCompiler(object):
             introspection_obj = self._compile(c_path)
         except CompilerError as e:
             if not utils.have_debug_flag('save-temps'):
-                shutil.rmtree(tmpdir)
+                utils.rmtree(tmpdir)
             raise SystemExit('compilation of temporary binary failed:' + str(e))
 
         try:
             self._link(bin_path, introspection_obj)
         except LinkerError as e:
             if not utils.have_debug_flag('save-temps'):
-                shutil.rmtree(tmpdir)
+                utils.rmtree(tmpdir)
             raise SystemExit('linking of temporary binary failed: ' + str(e))
 
         return IntrospectionBinary([bin_path], tmpdir)
diff --git a/giscanner/gdumpparser.py b/giscanner/gdumpparser.py
index bd4d233a..cd9d94d2 100644
--- a/giscanner/gdumpparser.py
+++ b/giscanner/gdumpparser.py
@@ -26,7 +26,6 @@ from __future__ import unicode_literals
 import os
 import sys
 import tempfile
-import shutil
 import subprocess
 from xml.etree.cElementTree import parse
 
@@ -181,7 +180,7 @@ blob containing data gleaned from GObject's primitive introspection."""
             return parse(out_path)
         finally:
             if not utils.have_debug_flag('save-temps'):
-                shutil.rmtree(self._binary.tmpdir)
+                utils.rmtree(self._binary.tmpdir)
 
     # Parser
 
diff --git a/giscanner/utils.py b/giscanner/utils.py
index 09132b2d..f6cd0b4f 100644
--- a/giscanner/utils.py
+++ b/giscanner/utils.py
@@ -27,6 +27,8 @@ import re
 import os
 import subprocess
 import platform
+import shutil
+import time
 
 
 _debugflags = None
@@ -291,3 +293,26 @@ def get_system_data_dirs():
         xdg_data_dirs.append('/usr/share')
 
     return xdg_data_dirs
+
+
+def rmtree(*args, **kwargs):
+    '''
+    A variant of shutil.rmtree() which waits and tries again in case one of
+    the files in the directory tree can't be deleted.
+
+    This can be the case if a file is still in use by some process,
+    for example a Virus scanner on Windows scanning .exe files when they are
+    created.
+    '''
+
+    tries = 3
+    for i in range(1, tries + 1):
+        try:
+            shutil.rmtree(*args, **kwargs)
+        except OSError:
+            if i == tries:
+                raise
+            time.sleep(i)
+            continue
+        else:
+            return