msetup: Fix callig meson --wipe inside a build directory

This seems to be related to deleting the current working directory.
Simply deleting all of the trees inside the build directory instead
seems to fix it. This only appears with some combination of generated
targets, running the test case against say "1 trivial" doesn't show the
bug.

See this mesa bug: https://bugs.freedesktop.org/show_bug.cgi?id=109071

mesonbuild/mesonlib.py

@@ -1116,6 +1116,22 @@ def windows_proof_rmtree(f):
     shutil.rmtree(f)
 
 
+def windows_proof_rm(fpath):
+    """Like windows_proof_rmtree, but for a single file."""
+    if os.path.isfile(fpath):
+        os.chmod(fpath, os.stat(fpath).st_mode | stat.S_IWRITE | stat.S_IREAD)
+    delays = [0.1, 0.1, 0.2, 0.2, 0.2, 0.5, 0.5, 1, 1, 1, 1, 2]
+    for d in delays:
+        try:
+            os.unlink(fpath)
+            return
+        except FileNotFoundError:
+            return
+        except (OSError, PermissionError):
+            time.sleep(d)
+    os.unlink(fpath)
+
+
 def detect_subprojects(spdir_name, current_dir='', result=None):
     if result is None:
         result = {}

mesonbuild/msetup.py

@@ -73,7 +73,15 @@ class MesonApp:
             coredata.read_cmd_line_file(self.build_dir, options)
 
             try:
-                mesonlib.windows_proof_rmtree(self.build_dir)
+                # Don't delete the whole tree, just all of the files and
+                # folders in the tree. Otherwise calling wipe form the builddir
+                # will cause a crash
+                for l in os.listdir(self.build_dir):
+                    l = os.path.join(self.build_dir, l)
+                    if os.path.isdir(l):
+                        mesonlib.windows_proof_rmtree(l)
+                    else:
+                        mesonlib.windows_proof_rm(l)
             finally:
                 # Restore the file
                 path = os.path.dirname(filename)

run_unittests.py

@@ -2922,11 +2922,7 @@ recommended as it is not supported on some platforms''')
         self.wipe()
         self.init(testdir, extra_args=['-Dstart_native=true'])
 
-    def test_reconfigure(self):
-        testdir = os.path.join(self.unit_test_dir, '46 reconfigure')
-        self.init(testdir, extra_args=['-Dopt1=val1'])
-        self.setconf('-Dopt2=val2')
-
+    def __reconfigure(self):
         # Set an older version to force a reconfigure from scratch
         filename = os.path.join(self.privatedir, 'coredata.dat')
         with open(filename, 'rb') as f:
@@ -2935,6 +2931,13 @@ recommended as it is not supported on some platforms''')
         with open(filename, 'wb') as f:
             pickle.dump(obj, f)
 
+    def test_reconfigure(self):
+        testdir = os.path.join(self.unit_test_dir, '46 reconfigure')
+        self.init(testdir, extra_args=['-Dopt1=val1'])
+        self.setconf('-Dopt2=val2')
+
+        self.__reconfigure()
+
         out = self.init(testdir, extra_args=['--reconfigure', '-Dopt3=val3'])
         self.assertRegex(out, 'WARNING:.*Regenerating configuration from scratch')
         self.assertRegex(out, 'opt1 val1')
@@ -2957,6 +2960,14 @@ recommended as it is not supported on some platforms''')
         self.build()
         self.run_tests()
 
+    def test_wipe_from_builddir(self):
+        testdir = os.path.join(self.common_test_dir, '162 custom target subdir depend files')
+        self.init(testdir)
+        self.__reconfigure()
+
+        with Path(self.builddir):
+            self.init(testdir, extra_args=['--wipe'])
+
     def test_target_construct_id_from_path(self):
         # This id is stable but not guessable.
         # The test is supposed to prevent unintentional