我试图使用python-clang
从C ++中的类实例化中提取模板参数,即。 libclang
的Python绑定(clang
3.9)。例如,对于
template <typename T> class X {};
X<bool> x;
我希望能够确定X
是以bool
为模板参数进行实例化的。
首先,似乎某些功能(例如get_num_template_arguments
)并未首先通过python-clang
公开,这是cymbal似乎对猴子补丁发挥作用的地方python-clang
。
有了这个,我能够做到这一点:
#!/usr/bin/env python
import clang.cindex
clang.cindex.Config.set_library_file('/usr/lib/x86_64-linux-gnu/libclang-3.9.so.1')
index = clang.cindex.Index.create()
source = """
template <typename T> class X {};
X<bool> x;
"""
######### stolen from cymbal
from ctypes import c_uint, c_int
def find_libclang_function(function):
return getattr(clang.cindex.conf.lib, function)
def monkeypatch_helper(classtype, name, library_function, args, result):
if hasattr(classtype, name):
raise ('failed to add method, %s is already available' % name)
f = find_libclang_function(library_function)
f.argtypes = args
f.restype = result
def impl(*args):
return f(*args)
setattr(classtype, name, impl)
def monkeypatch_type(method_name, library_function, args, result):
monkeypatch_helper(clang.cindex.Type, method_name, library_function, args, result)
monkeypatch_type('get_template_argument_type',
'clang_Type_getTemplateArgumentAsType',
[clang.cindex.Type, c_uint],
clang.cindex.Type)
monkeypatch_type('get_num_template_arguments',
'clang_Type_getNumTemplateArguments',
[clang.cindex.Type],
c_int)
######### /stolen from cymbal
# helpers for visiting the AST recursively
def visit(node, func):
func(node)
for c in node.get_children():
visit(c, func)
def visit_depth(node, func, depth=0):
func(node, depth)
for c in node.get_children():
visit_depth(c, func, depth+1)
# parse the TU
tu = clang.cindex.TranslationUnit.from_source('t.cpp', ['-std=c++11'], unsaved_files=[('t.cpp', source)])
# show the AST
def astprinter(node, depth):
print " "*depth, node.kind, node.spelling
visit_depth(tu.cursor, astprinter)
# find everything with a template and try to extract the template argument
def template_finder(node):
if hasattr(node, 'type') and node.type.get_num_template_arguments() != -1:
print node.type.get_num_template_arguments(), node.spelling, node.kind, node.get_template_argument_type(0).kind
visit(tu.cursor, template_finder)
输出:
CursorKind.TRANSLATION_UNIT t.cpp
CursorKind.CLASS_TEMPLATE X
CursorKind.TEMPLATE_TYPE_PARAMETER T
CursorKind.VAR_DECL x
CursorKind.TEMPLATE_REF X
CursorKind.CALL_EXPR X
1 x CursorKind.VAR_DECL TypeKind.INVALID
1 X CursorKind.CALL_EXPR TypeKind.INVALID
我期待node.get_template_argument_type(0).kind
中的template_finder
返回一些内容引导我bool
,但我无法找到任何内容。这是正确的方法吗?甚至可以将模板参数设置为当前状态python-clang
?
答案 0 :(得分:1)
我认为你真正缺少的是模板查找器中的几个地方的.type
,但作为参考,这对我来说很有用,即使是在3.7岁的铿锵声中
import clang.cindex
from clang.cindex import *
import cymbal
from ctypes import *
cymbal.monkeypatch_type('get_template_argument_type',
'clang_Type_getTemplateArgumentAsType',
[Type, c_uint],
Type)
cymbal.monkeypatch_type('get_num_template_arguments',
'clang_Type_getNumTemplateArguments',
[Type],
c_int)
# check if the cursor's type is a template
def is_template(node):
return hasattr(node, 'type') and node.type.get_num_template_arguments() != -1
index = clang.cindex.Index.create()
source = """
template <typename T> class X {};
X<bool> x;
"""
# parse the TU
tu = clang.cindex.TranslationUnit.from_source('t.cpp', ['-std=c++11'], unsaved_files=[('t.cpp', source)])
for c in tu.cursor.walk_preorder():
if is_template(c):
t = c.type
print t.kind, t.spelling, t.get_num_template_arguments()
print t.get_template_argument_type(0).spelling
给出了:
TypeKind.UNEXPOSED X<bool> 1
bool
TypeKind.UNEXPOSED X<bool> 1
bool