When GLib code is checked out with Windows line endings (happens on Windows), data-to-c.py embedded that line endings into generated string literal. And then they translated to double newlines in glib-compile-resources output.
clang-cl failed to compile such files because of empty lines in the middle of multiline macros:
#define G_MSVC_CTOR(_func,_sym_prefix) \ static void _func(void); \
To fix the issue, enable 'universal newlines' mode when reading the input in data-to-c.py - translate both '\n' and '\r\n' to '\n'.
Fixes #2340 (closed)