review: use shlex.split.

Signed-off-by: Piotr Sikora <piotrsikora@google.com>

Author: PiotrSikora

bazel/cc_wrapper.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python
 import contextlib
 import os
+import shlex
 import sys
 import tempfile
 
@@ -29,7 +30,7 @@ def sanitize_flagfile(in_path, out_fd):
 def main():
   # Append CXXFLAGS to correctly detect include paths for either libstdc++ or libc++.
   if sys.argv[1:5] == ["-E", "-xc++", "-", "-v"]:
-    os.execv(envoy_real_cxx, [envoy_real_cxx] + sys.argv[1:] + envoy_cxxflags.split(" "))
+    os.execv(envoy_real_cxx, [envoy_real_cxx] + sys.argv[1:] + shlex.split(envoy_cxxflags))
 
   # `g++` and `gcc -lstdc++` have similar behavior and Bazel treats them as
   # interchangeable, but `gcc` will ignore the `-static-libstdc++` flag.
@@ -49,7 +50,7 @@ def main():
   if "-static-libstdc++" in sys.argv[1:] or "-stdlib=libc++" in envoy_cxxflags:
     # Append CXXFLAGS to all C++ targets (this is mostly for dependencies).
     if envoy_cxxflags and "-std=c++" in str(sys.argv[1:]):
-      argv = envoy_cxxflags.split(" ")
+      argv = shlex.split(envoy_cxxflags)
     else:
       argv = []
     for arg in sys.argv[1:]: