[XEN PATCH for-4.17 v2 3/6] tools/include/xen-foreign: Add SPDX identifier to generated headers

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

The headers install in "/usr/include/xen/foreign/" are missing a
licence header. This patch adds a SPDX identifier to clarify that
the MIT licence is used.

The script now check that the licence of the input file is also MIT,
by checking for the presence of the SPDX identifier.

Also add information about which files are used to generate the
headers.

Reported-by: Andrew Cooper <Andrew.Cooper3@xxxxxxxxxx>
Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---

Notes:
    v2:
    - Add a SPDX identifier instead of trying to capture the original
      licence text.
    - Check the SPDX identifier of the input headers.
    - Add information about which headers are used as input.

 tools/include/xen-foreign/mkheader.py | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/tools/include/xen-foreign/mkheader.py 
b/tools/include/xen-foreign/mkheader.py
index fb268f0dce..ec8a321395 100644
--- a/tools/include/xen-foreign/mkheader.py
+++ b/tools/include/xen-foreign/mkheader.py
@@ -1,5 +1,6 @@
 #!/usr/bin/python
 
+from __future__ import print_function
 import sys, re;
 from structs import unions, structs, defines;
 
@@ -114,23 +115,37 @@ input  = "";
 output = "";
 fileid = re.sub("[-.]", "_", "__FOREIGN_%s__" % outfile.upper());
 
-# read input header files
 for name in infiles:
     f = open(name, "r");
+    # Check the licence of the input file, only SPDX identifier is accepted by
+    # this script.
+    line = f.readline()
+    if not line == "/* SPDX-License-Identifier: MIT */\n":
+        print("%s: Error: %s is missing SPDX identifier" % (sys.argv[0], 
name), file=sys.stderr)
+        exit(1)
     input += f.read();
     f.close();
 
+# replace path in "infiles" by path in '/usr/include' to avoid exposing the
+# build directory path in the generated headers.
+headers_name_list = ""
+public_headers_location = 'xen/include/public/'
+for name in infiles:
+    i = name.rindex(public_headers_location)
+    i += len(public_headers_location)
+    headers_name_list += " xen/%s" % (name[i:])
+
 # add header
-output += """
+output += """/* SPDX-License-Identifier: MIT */
 /*
  * public xen defines and struct for %s
- * generated by %s -- DO NOT EDIT
+ * generated from%s by %s -- DO NOT EDIT
  */
 
 #ifndef %s
 #define %s 1
 
-""" % (arch, sys.argv[0], fileid, fileid)
+""" % (arch, headers_name_list, sys.argv[0], fileid, fileid)
 
 if arch in header:
     output += header[arch];
-- 
Anthony PERARD