使用 libclang 查找匿名枚举

有没有一种方法可以使用 libclang 检测匿名枚举而不依赖于拼写名称中的文本？

python 绑定到libclang https://raw.githubusercontent.com/llvm-mirror/clang/release_36/bindings/python/clang/cindex.py包含检测 C/C++ 结构或联合是否是匿名的功能clang.cindex.Cursor.is_anonymous https://github.com/llvm-mirror/clang/blob/release_37/bindings/python/clang/cindex.py#L1483，最终调用clang_Cursor_isAnonymous http://clang.llvm.org/doxygen/group__CINDEX__TYPES.html#ga6e0d2674d126fd43816ce3a80b592373.

以下示例演示了该问题。

import sys
from clang.cindex import *

def nodeinfo(n):
    return (n.kind, n.is_anonymous(), n.spelling, n.type.spelling)

idx = Index.create()

# translation unit parsed correctly
tu = idx.parse(sys.argv[1], ['-std=c++11'])
assert(len(tu.diagnostics) == 0)

for n in tu.cursor.walk_preorder():
    if n.kind == CursorKind.STRUCT_DECL and n.is_anonymous():
        print nodeinfo(n)
    if n.kind == CursorKind.UNION_DECL and n.is_anonymous():
        print nodeinfo(n)
    if n.kind == CursorKind.ENUM_DECL:
        if n.is_anonymous():
            print nodeinfo(n)
        else:
            print 'INCORRECT', nodeinfo(n)

当在sample.cpp上运行时

enum
{
    VAL = 1
};

struct s
{
    struct {};
    union
    {
        int x;
        float y;
    };
};

Gives:

INCORRECT (CursorKind.ENUM_DECL, False, '', '(anonymous enum at sample1.cpp:1:1)')
(CursorKind.STRUCT_DECL, True, '', 's::(anonymous struct at sample1.cpp:8:5)')
(CursorKind.UNION_DECL, True, '', 's::(anonymous union at sample1.cpp:9:5)')

很遗憾clang_Cursor_isAnonymous仅适用于结构和联合，正如您可以从 clang 源代码中看到的那样工具/libclang/CXType.cpp https://github.com/llvm-mirror/clang/blob/master/tools/libclang/CXType.cpp#L978

unsigned clang_Cursor_isAnonymous(CXCursor C){
  if (!clang_isDeclaration(C.kind))
    return 0;
  const Decl *D = cxcursor::getCursorDecl(C);
  if (const RecordDecl *FD = dyn_cast_or_null<RecordDecl>(D))
    return FD->isAnonymousStructOrUnion();
  return 0;
}

所以回退到conf.lib.clang_Cursor_isAnonymous in clang.cindex.Cursor.is_anonymous https://github.com/llvm-mirror/clang/blob/release_37/bindings/python/clang/cindex.py#L1483没有做任何新的事情，因为游标类型已经根据FIELD_DECL进行了检查（仅适用于结构和联合）

def is_anonymous(self):
        """
        Check if the record is anonymous.
        """
        if self.kind == CursorKind.FIELD_DECL:
            return self.type.get_declaration().is_anonymous()
        return conf.lib.clang_Cursor_isAnonymous(self)

您可以尝试提取当前元素的标识符（n在您的示例中）并检查它是否存在或为空