1 files changed, 29 insertions, 33 deletions

diff --git a/src/python/grpcio/_unixccompiler_patch.py b/src/python/grpcio/_spawn_patch.py
index 894c3ef395..24306f0dd9 100644
--- a/src/python/grpcio/_unixccompiler_patch.py
+++ b/src/python/grpcio/_spawn_patch.py
@@ -27,51 +27,47 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-"""Covers inadequacies in distutils."""
+"""Patches the spawn() command for windows compilers.
+
+Windows has an 8191 character command line limit, but some compilers
+support an @command_file directive where command_file is a file
+containing the full command line.
+"""
 
 from distutils import ccompiler
-from distutils import errors
-from distutils import unixccompiler
 import os
 import os.path
-import shlex
 import shutil
 import sys
 import tempfile
 
-def _unix_commandfile_spawn(self, command):
-  """Wrapper around distutils.util.spawn that attempts to use command files.
+MAX_COMMAND_LENGTH = 8191
 
-  Meant to replace the CCompiler method `spawn` on UnixCCompiler and its
-  derivatives (e.g. the MinGW32 compiler).
+_classic_spawn = ccompiler.CCompiler.spawn
 
-  Some commands like `gcc` (and friends like `clang`) support command files to
-  work around shell command length limits.
-  """
-  # Sometimes distutils embeds the executables as full strings including some
-  # hard-coded flags rather than as lists.
-  command = list(shlex.split(command[0])) + list(command[1:])
-  command_base = os.path.basename(command[0].strip())
-  if command_base == 'ccache':
-    command_base = command[:2]
-    command_args = command[2:]
-  elif command_base.startswith('ccache') or command_base in ['gcc', 'clang', 'clang++', 'g++']:
-    command_base = command[:1]
-    command_args = command[1:]
+def _commandfile_spawn(self, command):
+  command_length = sum([len(arg) for arg in command])
+  if os.name == 'nt' and command_length > MAX_COMMAND_LENGTH:
+    # Even if this command doesn't support the @command_file, it will
+    # fail as is so we try blindly
+    print('Command line length exceeded, using command file')
+    print(' '.join(command))
+    temporary_directory = tempfile.mkdtemp()
+    command_filename = os.path.abspath(
+    os.path.join(temporary_directory, 'command'))
+    with open(command_filename, 'w') as command_file:
+      escaped_args = ['"' + arg.replace('\\', '\\\\') + '"' for arg in command[1:]]
+      command_file.write(' '.join(escaped_args))
+    modified_command = command[:1] + ['@{}'.format(command_filename)]
+    try:
+      _classic_spawn(self, modified_command)
+    finally:
+      shutil.rmtree(temporary_directory)
   else:
-    return ccompiler.CCompiler.spawn(self, command)
-  temporary_directory = tempfile.mkdtemp()
-  command_filename = os.path.abspath(os.path.join(temporary_directory, 'command'))
-  with open(command_filename, 'w') as command_file:
-    escaped_args = [arg.replace('\\', '\\\\') for arg in command_args]
-    command_file.write(' '.join(escaped_args))
-  modified_command = command_base + ['@{}'.format(command_filename)]
-  result = ccompiler.CCompiler.spawn(self, modified_command)
-  shutil.rmtree(temporary_directory)
-  return result
+    _classic_spawn(self, command)
 
 
-def monkeypatch_unix_compiler():
+def monkeypatch_spawn():
   """Monkeypatching is dumb, but it's either that or we become maintainers of
      something much, much bigger."""
-  unixccompiler.UnixCCompiler.spawn = _unix_commandfile_spawn
+  ccompiler.CCompiler.spawn = _commandfile_spawn