libclang: Spelling on typedefs lacks namespaces

Hi

Hope I picked the right place for this kind of problem, if not please let me know.

I'm using libclang to parse header files and generate code from them. I found that clang_getTypeSpelling() usually includes the namespace(s) a type was declared in. However with the exception being typedefs (and same for "using A = B"). Not sure if this is a bug or intended behavior, but it seems at least inconsistent. I also couldn't really find a good workaround for this. I'd have to manually figure out all typedefs (not just pure typedefs, they could also be template parameters or whatever) and then their originating namespaces. This sounds a bit cumbersome and not really straight forward.

Minimal example:

namespace foo {
class Bar {
};
typedef Bar BarDef;
}

clang_getTypeSpelling on "Bar" (kind "Record") gives: "foo::Bar"
clang_getTypeSpelling on "BarDef" (kind "Typedef") gives: "BarDef" (<== missing "foo::")

Any idea how to solve this problem? Am I missing something?

Thanks

Michael

Nobody? Wrong list? Any insight in this would be greatly appreciated.

Thanks

Michael

Hi Michael,

I haven’t used libclang much (my use case requires LibTooling) but I think you want to get the underlying type from the typedef and then use getTypeSpelling on that result. Basically you want to check if CXType.kind is CXType_Typedef and if so, get the underlying type (which in this case should be “Bar”) and then call clang_getTypeSpelling on that result.

I don’t know anything about CXCursors or CXTypes so I’ll leave it to you to figure out how to get the underlying type, but hopefully this helps.

-Adam

I think you want to get the underlying type from the typedef and then

use getTypeSpelling on that result.

Hmm, I don't think so, I actually would like to keep the typedefs in my generated code (for readability, and because it might actually resolve to something different when the generated code is used or to something clang specific which then fails with other compilers). Also the underlying type could again contain typedefs with missing namespace, so I would have to go all the way down to the canonical type (which is what I'm actually doing currently as a workaround)...

Michael

I had a look into the clang sources. It seems this little patch would "fix" the problem. This was pure guess work, I don't know what consequences this might have.

Index: lib/AST/TypePrinter.cpp

While it generates some ugly code I found it easier to simply use the canonical names for all types. I spent tens of hours fighting this and never found a good way.