Clang++ Type Name 'Mangling'

The code:

#include <gsl/gsl_matrix.h>
#include <gsl/gsl_vector.h>

int main()
{
  gsl_matrix a;
  gsl_vector b;
  return 0;
}

With the command:

clang++ ffigen.cpp -S -emit-llvm

Compiles to:

; ModuleID = 'ffigen.cpp'
[...]

%0 = type { i64, i64, double*, %struct.gsl_block_struct*, i32 }
%struct.anon = type { i64, i64, i64, double*, %struct.gsl_block_struct*, i32 }
%struct.gsl_block_struct = type { i64, double* }

define i32 @main() nounwind {
  [...]
  %a = alloca %struct.anon, align 8
  %b = alloca %0, align 8
  [...]
}