Introduction

Managing versions and releases is an essential part of software development. It allows developers to track changes, ensure reproducibility, and deliver updates to users efficiently. In this blog post, we will discuss how to handle versioning and release management in C++ build systems. We will cover some best practices and tools that can help streamline the process.

1. Semantic Versioning

Semantic Versioning (SemVer) is a widely adopted versioning scheme that provides a clear and predictable way to define releases. SemVer uses three numbers separated by dots: MAJOR.MINOR.PATCH. Each number has its own meaning:

• MAJOR: Incremented when incompatible changes are made.
• MINOR: Incremented when new functionality is added in a backward-compatible manner.
• PATCH: Incremented when backward-compatible bug fixes are made.

By following SemVer, developers can communicate with users and other developers about the impact of a release and ensure compatibility between different versions of the software.

2. Versioning in C++ Projects

To incorporate versioning into a C++ project, you can use preprocessor directives and macros. Create a version.hpp header file that defines version-related macros, such as:

#ifndef VERSION_HPP
#define VERSION_HPP

#define PROJECT_VERSION_MAJOR 1
#define PROJECT_VERSION_MINOR 0
#define PROJECT_VERSION_PATCH 0

#endif

In your source files, include the version.hpp header and use the defined macros to retrieve the version information. For example:

#include "version.hpp"

void printVersion() {
    std::cout << "Version: " << PROJECT_VERSION_MAJOR << "." << PROJECT_VERSION_MINOR << "." << PROJECT_VERSION_PATCH << std::endl;
}

By centralizing version information in a header file, you can easily update it in one place and access it from multiple source files.

3. Build Systems and Versioning

Various build systems are available for C++ projects, such as CMake, Makefile, or custom scripts. These build systems should be configured to include version information during the build process.

3.1. CMake

If you are using CMake, you can utilize its variables and configurations to handle versioning. Create a CMakeLists.txt file with the following content:

cmake_minimum_required(VERSION 3.0)
project(MyProject)

# define version variables
set(PROJECT_VERSION_MAJOR 1)
set(PROJECT_VERSION_MINOR 0)
set(PROJECT_VERSION_PATCH 0)

# configure header file
configure_file(version.hpp.in ${PROJECT_SOURCE_DIR}/version.hpp)

# add source files and include directories
add_executable(MyProject main.cpp)
target_include_directories(MyProject PUBLIC ${PROJECT_SOURCE_DIR})

The version.hpp.in file contains placeholders that will be replaced by the configured values during the build process. Here is an example version.hpp.in:

#ifndef VERSION_HPP
#define VERSION_HPP

#define PROJECT_VERSION_MAJOR @PROJECT_VERSION_MAJOR@
#define PROJECT_VERSION_MINOR @PROJECT_VERSION_MINOR@
#define PROJECT_VERSION_PATCH @PROJECT_VERSION_PATCH@

#endif

When CMake generates the build files, it replaces the placeholders with the specified values, resulting in the version.hpp file you defined earlier.

3.2. Makefile

If you are using Makefile as your build system, you can update the version information by passing arguments during the build command. For example:

CC=g++
CFLAGS=-c -Wall
LDFLAGS=
SOURCES=main.cpp
OBJECTS=$(SOURCES:.cpp=.o)
EXECUTABLE=myproject

# define default version values
PROJECT_VERSION_MAJOR ?= 1
PROJECT_VERSION_MINOR ?= 0
PROJECT_VERSION_PATCH ?= 0

all: $(SOURCES) $(EXECUTABLE)

$(EXECUTABLE): $(OBJECTS)
	$(CC) $(LDFLAGS) $(OBJECTS) -o $@

.cpp.o:
	$(CC) $(CFLAGS) $< -o $@

version.hpp:
	@echo "#ifndef VERSION_HPP" > $@
	@echo "#define VERSION_HPP" >> $@
	@echo "" >> $@
	@echo "#define PROJECT_VERSION_MAJOR $(PROJECT_VERSION_MAJOR)" >> $@
	@echo "#define PROJECT_VERSION_MINOR $(PROJECT_VERSION_MINOR)" >> $@
	@echo "#define PROJECT_VERSION_PATCH $(PROJECT_VERSION_PATCH)" >> $@
	@echo "" >> $@
	@echo "#endif" >> $@

clean:
	rm -f $(EXECUTABLE) $(OBJECTS) version.hpp

.PHONY: all clean

By running the following command, you can specify the desired version values:

make PROJECT_VERSION_MAJOR=2 PROJECT_VERSION_MINOR=1 PROJECT_VERSION_PATCH=3

The Makefile targets will create the version.hpp file with the updated version values and compile the project accordingly.

Conclusion

For C++ projects, versioning and release management play crucial roles in software development. By adopting Semantic Versioning, defining version macros in a version.hpp header, and configuring your build system to handle version information, you can easily manage versions and releases. Whether you are using CMake or Makefile, the provided examples demonstrate how to incorporate versioning into your C++ build process.

Remember that consistent and clear versioning helps users and developers interact with your software effectively and ensures smooth collaboration and deployment.

#C++ #Versioning