clang-uml is an automatic C++ to UML class, sequence, package and include diagram generator, driven by
YAML configuration files. The main idea behind the
project is to easily maintain up-to-date diagrams within a code-base or document
legacy code. The configuration file or files for clang-uml define the
types and contents of each generated diagram.
The diagrams can be generated in PlantUML,
MermaidJS and JSON formats.
clang-uml currently supports C++ up to version 17 with partial support for C++ 20.
Full documentation can be found at clang-uml.github.io.
To see what clang-uml can do, checkout the diagrams generated for unit
test cases here or examples in
clang-uml-examples repository.
Main features supported so far include:
- Class diagram generation
- Class properties and methods including access scope - example
- Class inheritance - example
- Other class relationships including associations, aggregations, dependencies and friendship - example
- Template instantiation relationships - example
- Template specialization and instantiation based on deduced context - example
- Relationship inference from C++ containers and smart pointers - example
- Diagram content filtering based on namespaces, elements and relationships - example
- Optional package generation from namespaces (only PlantUML) - example
- Optional package generation from subdirectories (only PlantUML) - example
- Optional package generation from C++20 modules (only PlantUML) - example
- Interactive links to online code or docs for classes, methods and class fields in SVG diagrams - example
- Support for plain C99/C11 code (struct, units and their relationships) - example
- C++20 concept constraints - example
- C++20 coroutines - example
- Diagram content filtering based on C++20 modules - example
- Sequence diagram generation
- Generation of sequence diagram from specific method or function - example
- Generation of loop and conditional statements - example
- Generation of switch statements - example
- Generation of try/catch blocks - example
- Handling of template code including constexpr conditionals - example
- Handling of lambda expressions - example
- Interactive links to online code to classes and call expressions - example
- Support for CUDA Kernel and CUDA Device function calls - example
- Package diagram generation
- Generation of package diagram based on C++ namespaces - example
- Generation of package diagram based on subdirectories - example
- Generation of package diagram based on C++20 modules - example
- Dependencies between packages based on symbols used in the code - example
- Interactive links to online code to packages - example
- Include graph diagram generation
- Show include graph for selected files - example
More comprehensive documentation can be at clang-uml.github.io.
Installation instructions for Linux, macos and Windows can be found
here.
clang-uml requires an up-to-date
compile_commands.json
file, containing the list of commands used for compiling the source code.
Nowadays, this file can be generated rather easily using multiple methods:
- For CMake projects, simply invoke the
cmakecommand ascmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON ... - For Make projects checkout compiledb or Bear
- For Boost-based projects try commands_to_compilation_database
- For SCons, invoke
compilation_dbtool (requires SCons > 4.0.0) - For Bazel, try bazel-compile-commands-extractor
- For Microsoft Visual Studio projects try Clang Power Tools
By default, clang-uml will assume that the configuration file .clang-uml
and compilation database compile_commands.json files are in the
current directory, so if they are in the top level directory of a project,
simply run:
clang-umlThe output path for diagrams, as well as alternative location of
compilation database can be specified in .clang-uml configuration file.
For other options checkout help:
clang-uml --helpConfiguration files are written in YAML, and provide a list of diagrams
which should be generated by clang-uml. Basic example is as follows:
compilation_database_dir: .
output_directory: diagrams
diagrams:
myproject_class:
type: class
glob:
- src/*.cc
using_namespace: myproject
include:
namespaces:
- myproject
exclude:
namespaces:
- myproject::detail
plantuml:
after:
- 'note left of {{ alias("MyProjectMain") }}: Main class of myproject library.'See here for detailed configuration file reference guide.
To see what clang-uml can do, checkout the test cases documentation here.
In order to see diagrams for the clang-uml itself, based on its own config run
the following:
make clanguml_diagramsand checkout the SVG diagrams in docs/diagrams folder.
The following C++ code:
template <typename T, typename P> struct A {
T t;
P p;
};
struct B {
std::string value;
};
template <typename T> using AString = A<T, std::string>;
template <typename T> using AStringPtr = A<T, std::unique_ptr<std::string>>;
template <typename T>
using PairPairBA = std::pair<std::pair<B, A<long, T>>, long>;
template <class T> using VectorPtr = std::unique_ptr<std::vector<T>>;
template <class T> using APtr = std::unique_ptr<A<double, T>>;
template <class T> using ASharedPtr = std::shared_ptr<A<double, T>>;
template <class T, class U>
using AAPtr = std::unique_ptr<std::pair<A<double, T>, A<long, U>>>;
template <typename T> using SimpleCallback = std::function<void(T, int)>;
template <typename... T> using GenericCallback = std::function<void(T..., int)>;
using VoidCallback = GenericCallback<void *>;
using BVector = std::vector<B>;
using BVector2 = BVector;
using AIntString = AString<int>;
using ACharString = AString<char>;
using AStringString = AString<std::string>;
using BStringString = AStringString;
template <typename T> class R {
using AWCharString = AString<wchar_t>;
PairPairBA<bool> bapair;
APtr<bool> abool;
AAPtr<bool, float> aboolfloat;
ASharedPtr<float> afloat;
A<bool, std::string> boolstring;
AStringPtr<float> floatstring;
AIntString intstring;
AStringString stringstring;
BStringString bstringstring;
AAPtr<T, float> atfloat;
protected:
BVector bs;
public:
BVector2 bs2;
SimpleCallback<ACharString> cb;
GenericCallback<AWCharString> gcb;
VoidCallback vcb;
VectorPtr<B> vps;
};results in the following diagram (via PlantUML):
Open the raw image here, and checkout the hover tooltips and hyperlinks to classes and methods.
The following C++ code:
#include <atomic>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
namespace clanguml {
namespace t20029 {
std::string encode_b64(std::string &&content) { return std::move(content); }
template <typename T> class Encoder : public T {
public:
bool send(std::string &&msg)
{
return T::send(std::move(
// Encode the message using Base64 encoding and pass it to the next
// layer
encode(std::move(msg))));
}
protected:
std::string encode(std::string &&msg) { return encode_b64(std::move(msg)); }
};
template <typename T> class Retrier : public T {
public:
bool send(std::string &&msg)
{
std::string buffer{std::move(msg)};
int retryCount = 5;
// Repeat until send() succeeds or retry count is exceeded
while (retryCount--) {
if (T::send(buffer))
return true;
}
return false;
}
};
class ConnectionPool {
public:
void connect()
{
if (!is_connected_.load())
connect_impl();
}
bool send(const std::string &msg) { return true; }
private:
void connect_impl() { is_connected_ = true; }
std::atomic<bool> is_connected_;
};
int tmain()
{
auto pool = std::make_shared<Encoder<Retrier<ConnectionPool>>>();
// Establish connection to the remote server synchronously
pool->connect();
// Repeat for each line in the input stream
for (std::string line; std::getline(std::cin, line);) {
if (!pool->send(std::move(line)))
break;
}
return 0;
}
}
}results in the following diagram (via PlantUML):
The following C++ code:
namespace clanguml {
namespace t30003 {
namespace ns1 {
namespace ns2_v1_0_0 {
class A {
};
}
namespace [[deprecated]] ns2_v0_9_0 {
class A {
};
}
namespace {
class Anon final {
};
}
}
namespace [[deprecated]] ns3 {
namespace ns1::ns2 {
class Anon : public t30003::ns1::ns2_v1_0_0::A {
};
}
class B : public ns1::ns2::Anon {
};
}
}
}results in the following diagram (via PlantUML):
In case you're looking for a simpler tool to visualize and analyze include graphs checkout my other tool - clang-include-graph
The following C++ code structure:
tests/t40001
├── include
│ ├── lib1
│ │ └── lib1.h
│ └── t40001_include1.h
└── src
└── t40001.cc
results in the following diagram (via PlantUML) based on include directives in the code:
| UML | PlantUML | MermaidJS |
|---|---|---|
| Inheritance |  |
 |
| Association |  |
 |
| Dependency |  |
 |
| Aggregation |  |
 |
| Composition |  |
 |
| Template specialization/instantiation |  |
 |
| Nesting (inner class/enum) |  |
 |
| Include (local) | |
|
| Include (system) | |
|
For typical code bases, generating a single diagram from entire code or even a single namespace can be too big to
be useful, e.g. as part of documentation. clang-uml allows specifying content to be included and excluded from
each diagram using simple YAML configuration:
include:
# Include only elements from these namespaces
namespaces:
- clanguml::common
- clanguml::config
# Include all subclasses of ClassA (including ClassA)
subclasses:
- clanguml::common::ClassA
# and specializations of template Class<T> (including Class<T>)
specializations:
- clanguml::common::ClassT<T>
# and all classes depending on Class D
dependants:
- clanguml::common::ClassD
# and all dependencies of ClassE
dependencies:
- clanguml::common::ClassE
# and classes in direct relation to ClassB (including ClassB)
context:
- clanguml::common::ClassB
# Include only inheritance relationships
relationships:
- inheritance
exclude:
# Exclude all elements from detail namespace
namespaces:
- clanguml::common::detail
# and also exclude ClassF
elements:
- clanguml::common::ClassFMore details on this can be found in the diagram filters documentation section.
The build-in test cases used for unit testing of the clang-uml, can be browsed here.
This project relies on the following great tools:
- Clang LibTooling - a C++ library for creating tools based on Clang
- PlantUML - language and diagram for generating UML diagrams
- MermaidJS - JavaScript based diagramming and charting tool
- Catch2 - C++ unit test framework
- glob - Unix style path expansion for C++
- indicators - Activity indicators for modern C++
- CLI11 - command line parser for C++
- inja - a template engine for modern C++
- backward-cpp - stack trace pretty printer for C++
- yaml-cpp - YAML parser library for C++
- spdlog - Fast C++ logging library
- Doxygen - C++ documentation generator
- Doxygen Awesome - Doxygen CSS style
- miroir - YAML schema validation library for C++
If you would like to contribute to the project, please check out contributing guidelines.
Copyright 2021-present Bartek Kryza <[email protected]>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent
