Always use stdin=devnull when calling Popen.

theano/gof/cmodule.py

@@ -1481,11 +1481,9 @@ def gcc_llvm():
     """
     if gcc_llvm.is_llvm is None:
         pass
-        dummy_in = open(os.devnull)
         p = None
         try:
             p = call_subprocess_Popen(['g++', '--version'],
-                                      stdin=dummy_in.fileno(),
                                       stdout=subprocess.PIPE,
                                       stderr=subprocess.PIPE)
             p.wait()
@@ -1499,7 +1497,6 @@ def gcc_llvm():
             # will crash later so supposing it is not llvm is "safe".
             output = ''
         del p
-        del dummy_in
         gcc_llvm.is_llvm = "llvm" in output
     return gcc_llvm.is_llvm
 gcc_llvm.is_llvm = None
@@ -1546,16 +1543,11 @@ class GCC_compiler(object):
             GCC_compiler.march_flags = []
 
             def get_lines(cmd, parse=True):
-                dummy_in = open(os.devnull)
-                try:
                 p = call_subprocess_Popen(cmd,
-                                              stdin=dummy_in.fileno(),
                                           stdout=subprocess.PIPE,
                                           stderr=subprocess.PIPE,
                                           shell=True)
                 p.wait()
-                finally:
-                    del dummy_in
                 stdout = p.stdout.readlines()
                 stderr = p.stderr.readlines()
                 lines = []
@@ -1650,7 +1642,6 @@ class GCC_compiler(object):
         try:
             fd, path = tempfile.mkstemp(suffix='.c', prefix=tmp_prefix)
             exe_path = path[:-2]
-            dummy_stdin = open(os.devnull)
             try:
                 os.write(fd, src_code)
                 os.close(fd)
@@ -1658,8 +1649,7 @@ class GCC_compiler(object):
                 proc = call_subprocess_Popen(
                         ['g++', path, '-o', exe_path] + flags,
                         stdout=subprocess.PIPE,
-                        stderr=subprocess.PIPE,
-                        stdin=dummy_stdin.fileno())
+                        stderr=subprocess.PIPE)
                 proc.wait()
                 if proc.returncode != 0:
                     compilation_ok = False
@@ -1669,14 +1659,12 @@ class GCC_compiler(object):
                     try:
                         proc = call_subprocess_Popen([exe_path],
                                 stdout=subprocess.PIPE,
-                                stderr=subprocess.PIPE,
-                                stdin=dummy_stdin.fileno())
+                                stderr=subprocess.PIPE)
                         proc.wait()
                         run_ok = (proc.returncode == 0)
                     finally:
                         os.remove(exe_path)
             finally:
-                del dummy_stdin
                 try:
                     if fd is not None:
                         os.close(fd)

theano/gof/compiledir.py

@@ -18,13 +18,11 @@ from theano.misc.windows import call_subprocess_Popen
 # Using the dummy file descriptors below is a workaround for a crash
 # experienced in an unusual Python 2.4.4 Windows environment with the default
 # None values.
-dummy_in = open(os.devnull)
 dummy_err = open(os.devnull, 'w')
 p = None
 try:
     p = call_subprocess_Popen(['g++', '-dumpversion'],
                               stdout=subprocess.PIPE,
-                              stdin=dummy_in.fileno(),
                               stderr=dummy_err.fileno())
     p.wait()
     gcc_version_str = p.stdout.readline().strip().decode()
@@ -32,7 +30,6 @@ except OSError:
     # Typically means gcc cannot be found.
     gcc_version_str = 'GCC_NOT_FOUND'
 del p
-del dummy_in
 del dummy_err
 
 compiledir_format_dict = {"platform": platform.platform(),

theano/misc/windows.py

@@ -21,5 +21,18 @@ def call_subprocess_Popen(command, **params):
         # execute "g++" without extensions.
         # (Executing "g++.bat" explicitly would also work.)
         params['shell'] = True
+
+    # Using the dummy file descriptors below is a workaround for a
+    # crash experienced in an unusual Python 2.4.4 Windows environment
+    # with the default None values.
+    stdin = None
+    if "stdin" not in params:
+        stdin = open(os.devnull)
+        params['stdin'] = stdin.fileno()
+
+    try:
         proc = subprocess.Popen(command, startupinfo=startupinfo, **params)
+    finally:
+        if stdin is not None:
+            del stdin
     return proc

theano/tests/run_tests_in_batch.py

@@ -276,8 +276,7 @@ def run(stdout, stderr, argv, theano_nose, batch_size, time_profile,
                     # test name in display
                     # (see class 'DisabDocString' in file theano-nose)
                     stderr=subprocess.PIPE,
-                    stdout=dummy_out.fileno(),
-                    stdin=dummy_in.fileno())
+                    stdout=dummy_out.fileno())
 
                 # recovering and processing data from pipe
                 err = proc.stderr.read()