ccflags seems not ok

[guilvge]

hi:
when I use pygccxml, I used the code may cause some warning but error, and I know use which flag to fixed it.
for example: the code will show me [-Wnull-conversion], I can use flag " -Wno-null-conversion" to revert it, so I pass it in
ccflags=-Wno-null-conversion, but it is not ok, the last cmd will like:
"/usr/bin/castxml" -I"." -c -x c++ --castxml-cc-gnu "(" /usr/bin/clang++ -Wno-null-conversion ")" --castxml-gccxml -o /tmp/tmpxpsi9e2o.xml xxx, but it should be:
""/usr/bin/castxml" -I"." -c -x c++ -Wno-null-conversion --castxml-cc-gnu "(" /usr/bin/clang++ ")" --castxml-gccxml -o /tmp/tmpxpsi9e2o.xml xxx", the warning log will disapper by using this command. so I'm confused why the property "ccflags"
not work.

[guilvge]

hi:
I find the --castxml-cc- "(" ... ")" is only used in preprocessor, so compile stage may not use it, and there is still a parameter named "flags", it is not used. Maybe we can use it as clang-option.

[guilvge]

I think we can add clang-opt here for potential usage