Function xmlXPathDebugDumpCompExpr 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn xmlXPathDebugDumpCompExpr(
    output: *mut c_void,
    comp: *mut c_void,
    depth: c_int,
)

void xmlXPathDebugDumpCompExpr(FILE *output, xmlXPathCompExpr *comp, int depth).

The candidate’s compiled expressions are opaque registry handles; the dump prints the original expression text. NULL handles print nothing (matching upstream’s early return).

SAFETY

• output must be a valid FILE* or NULL; comp a compiled expression or NULL.