A simple cross-platform metadata generator for C/C++ programs. Works on any platform with Python 3.x.
Generates version defines based on closest reachable tag in git repository Format of git tag should be vX.Y.Z where Y and Z (with corresponding dots) are optional (treated as 0 if not present). If no git tag is available or even git is not available, generated version will be 0.0.0. If tag is not placed on current commit, "-SNAPSHOT" will be appended
C/C++ defines are added to meta.h header file. Include it to your project to access generated values.
| define | description |
|---|---|
| APPMETA_VERSION_STR | Version string. Based on latest reachable tag from current commit. In format vX.Y.Z (e.g. v2.1.3) |
| APPMETA_VERSION_FULL_STR | Full version string (same as version, but -SNAPSHOT is added if built from non tagged commit) |
| APPMETA_VERSION_MAJOR | Major version integer (e.g. 2) |
| APPMETA_VERSION_MINOR | Minor version integer (e.g. 1) |
| APPMETA_VERSION_PATCH | Patch version intgerer (e.g. 3) |
| APPMETA_VERSION_BUILD | Build integer. It is number of commits which were added since last version tag (0 if current commit is tagged) |
| APPMETA_BUILD_SNAPSHOT | 0 if current commit has tag, 1 otherwise |
| APPMETA_BUILD_DATE | String of build date in ISO8601 format (YYYY-MM-DD) |
| APPMETA_BUILD_COMMIT | String with current commit hash |
It is the simplest to use this builder with CMake project.
Suppose you have metagen.py located at ./libs/metagen/metagen.py.
Suppose in CMakeLists.txt you create your executable:
add_executable(YourExecutableName)
In CMakeLists.txt add following code:
find_package( PythonInterp 3.0 REQUIRED )
#if you put your meta files not in ./res folder make changes here
execute_process(COMMAND ${PYTHON_EXECUTABLE}
${PROJECT_SOURCE_DIR}/libs/metagen/metagen.py #path to python script that builds metadata
${PROJECT_SOURCE_DIR}/res #work directory where metadata config is stored
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
#meta information will be compiled in res/meta folder (it is specified in res/metagen.json)
#we only need to add it as subdirectory and link to created library
#name of the library is specified in metagen.json
add_subdirectory(res/meta)
target_link_libraries(metagen_example PRIVATE AppMeta)
It runs python script to generate all required files, and then you just write two lines to include everything in your project.
You need to place metagen.json inside res directory in your project root. This file has the following format:
{
// in output you should store the name of build folder. all generated files are placed there
"output" : "meta",
// project_name is used to prepend header defines so it doesn't collide with any of your defines
// it is also used to name library that you'll need to link your executable
"project_name" : "AppMeta",
// win_rc_template is path to template file for windows resource generation
// it is just a normal resource file, but all versions will be replaced with generated ones
// original file is not modified, generated is put into output directory
"win_rc_template": "win.rc"
}
Don't forget to remove comments if you use this sample (json doesn't support them).
In your code you can get version information by accessing one of the defines:
#include "AppMeta/meta.h"
#include <iostream>
// ...
std::cout << "Version is "<< APPMETA_VERSION_STR <<"\n";
std::cout << "Full version is "<< APPMETA_VERSION_FULL_STR <<"\n";
A fully functional CMake project is available in example directory to show how metadata is generated and accessed in
code.