生成C ++代码的调用图 [英] Generate calling graph for C++ code

问题描述

我试图生成调用图，用它来找出所有可能的执行路径，击中一个特定的函数（所以我不必手动计算出所有的路径，因为有许多路径导致到这个功能）。例如：

I'm trying to generate calling graph with which to find out all the possible execution paths that are hitting a particular function (so that I don't have to figure out all the paths manually, as there are many paths that lead to this function). For instance:

path 1: A -> B -> C -> D  
path 2: A -> B -> X -> Y -> D  
path 3: A -> G -> M -> N -> O -> P -> S -> D  
...  
path n: ...

Codeviz和Doxygen，不知何故这两个结果只显示目标函数的被调用者D.在我的情况下，D是一个类的成员函数，其对象将被包裹在智能指针内。客户端将总是通过工厂获取智能指针对象以调用D。

I have tried Codeviz and Doxygen, somehow both results show nothing but callees of target function, D. In my case, D is a member function of a class whose object will be wrapped within a smart pointer. Clients will always obtain the smart pointer object through a factory in order to invoke D.

有没有人知道如何实现这一点？

Does anyone know how to achieve this?

推荐答案

static void D() { }
static void Y() { D(); }
static void X() { Y(); }
static void C() { D(); X(); }
static void B() { C(); }
static void S() { D(); }
static void P() { S(); }
static void O() { P(); }
static void N() { O(); }
static void M() { N(); }
static void G() { M(); }
static void A() { B(); G(); }

int main() {
  A();
}

然后

$ clang++ -S -emit-llvm main1.cpp -o - | opt -analyze -dot-callgraph
$ dot -Tpng -ocallgraph.png callgraph.dot

产生一些闪光的图片（有一个外部节点，因为 main 有外部链接，并且可能从该翻译单元外部调用）：

Yields some shiny picture (there is an "external node", because main has external linkage and might be called from outside that translation unit too):

您可能希望使用 c ++ filt 进行后处理，以便可以获取涉及的函数和类的未解析名称。类似于以下

You may want to postprocess this with c++filt, so that you can get the unmangled names of the functions and classes involved. Like in the following

#include <vector>

struct A { 
  A(int);
  void f(); // not defined, prevents inlining it!
};

int main() {
  std::vector<A> v;
  v.push_back(42);
  v[0].f();
}

$ clang++ -S -emit-llvm main1.cpp -o - |
   opt -analyze -std-link-opts -dot-callgraph
$ cat callgraph.dot | 
   c++filt | 
   sed 's,>,\\>,g; s,-\\>,->,g; s,<,\\<,g' | 
   gawk '/external node/{id=$1} $1 != id' | 
   dot -Tpng -ocallgraph.png    

打开的优化太大了！）

这个神秘的未命名函数 Node0x884c4e0 是一个占位符，假定由任何未知定义的函数调用。

That mystical unnamed function, Node0x884c4e0, is a placeholder assumed to be called by any function whose definition is not known.

这篇关于生成C ++代码的调用图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！