Change windows escaping

Author: tannewt

ports/zephyr-cp/cptools/cpbuild.py

@@ -324,13 +324,14 @@ def __init__(self, srcdir: pathlib.Path, builddir: pathlib.Path, cmake_args):
         self.c_compiler = cmake_args["CC"]
         self.ar = cmake_args["AR"]
         self.cflags = cmake_args.get("CFLAGS", "")
-        print(self.cflags)
 
         self._cflags_tempfile = tempfile.NamedTemporaryFile()
 
-        # Windows paths have \ as separator but ar wants them as / (like UNIX)
-        unix_cflags = self.cflags.replace("\\", "/")
-        self._cflags_tempfile.write(unix_cflags.encode())
+        # Windows paths have \ as separator but gcc wants them escaped.
+        escaped_cflags = self.cflags.replace("\\", "\\\\")
+        print("writing:")
+        print(escaped_cflags)
+        self._cflags_tempfile.write(escaped_cflags.encode())
         self._cflags_tempfile.flush()
         self.cflags_file = "@" + self._cflags_tempfile.name