[PATCH 2/2] golang/xenlight: standardize generated code comment

[Nick Rosbrook <rosbrookn@xxxxxxxxx>]

There is a standard format for generated Go code header comments, as set
by [1]. Modify gengotypes.py to follow this standard, and use the
additional

  // source: <IDL file basename>

convention used by protoc-gen-go.

This change is motivated by the fact that since 41aea82de2, the comment
would include the absolute path to libxl_types.idl, therefore creating
unintended diffs when generating code across different machines. This
approach fixes that problem.

[1] https://github.com/golang/go/issues/13560

Signed-off-by: Nick Rosbrook <rosbrookn@xxxxxxxxxxxx>
---
 tools/golang/xenlight/gengotypes.py  | 10 ++++------
 tools/golang/xenlight/helpers.gen.go |  7 ++-----
 tools/golang/xenlight/types.gen.go   |  7 ++-----
 3 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/tools/golang/xenlight/gengotypes.py 
b/tools/golang/xenlight/gengotypes.py
index 4ac181ae47..3e40c3d5dc 100644
--- a/tools/golang/xenlight/gengotypes.py
+++ b/tools/golang/xenlight/gengotypes.py
@@ -731,13 +731,11 @@ if __name__ == '__main__':
         name = b.typename
         builtin_type_names[name] = xenlight_golang_fmt_name(name)
 
-    header_comment="""// DO NOT EDIT.
-//
-// This file is generated by:
-// {0}
-//
+    header_comment="""// Code generated by {}. DO NOT EDIT.
+// source: {}
 
-""".format(' '.join(sys.argv))
+""".format(os.path.basename(sys.argv[0]),
+           ' '.join([os.path.basename(a) for a in sys.argv[1:]]))
 
     xenlight_golang_generate_types(types=types,
                                    comment=header_comment)
diff --git a/tools/golang/xenlight/helpers.gen.go 
b/tools/golang/xenlight/helpers.gen.go
index 152c7e8e6b..c8605994e7 100644
--- a/tools/golang/xenlight/helpers.gen.go
+++ b/tools/golang/xenlight/helpers.gen.go
@@ -1,8 +1,5 @@
-// DO NOT EDIT.
-//
-// This file is generated by:
-// gengotypes.py ../../libxl/libxl_types.idl
-//
+// Code generated by gengotypes.py. DO NOT EDIT.
+// source: libxl_types.idl
 
 package xenlight
 
diff --git a/tools/golang/xenlight/types.gen.go 
b/tools/golang/xenlight/types.gen.go
index 663c1e86b4..b4c5df0f2c 100644
--- a/tools/golang/xenlight/types.gen.go
+++ b/tools/golang/xenlight/types.gen.go
@@ -1,8 +1,5 @@
-// DO NOT EDIT.
-//
-// This file is generated by:
-// gengotypes.py ../../libxl/libxl_types.idl
-//
+// Code generated by gengotypes.py. DO NOT EDIT.
+// source: libxl_types.idl
 
 package xenlight
 
-- 
2.17.1