Tools for C++ development¶

Estimated time to read: 45 minutes

• Version Control
  • GIT
  • Github
  • GitKraken
• Compiler
• CMake

Every programing language use different set of tools in order to effectively code. In C++ you will need to learn how to use a bunch of them to solve problems and develop software.

Version Control ¶

Version control are tools that help you to keep track of your code changes. It is a must have tool for any developer. You can keep track the state of your code, and if you mess up something, you can go back to a previous state. It is also a great tool to collaborate with other developers. You can work on the same codebase without messing up each other work.

GIT ¶

Git is a version control system that is used to track changes to files, including source code, documents, and other types of files. It allows multiple people to work on the same files concurrently, and it keeps track of all changes made to the files, making it easy to go back to previous versions or merge changes made by different people. Git is widely used by developers for managing source code, but it can be used to track changes to any type of file. It is particularly useful for coordinating work on projects that involve multiple people, as it allows everyone to see and track changes made by others.

Github ¶

Github is a web-based platform for version control and collaboration on software projects. It is a popular platform for developers to share and collaborate on code, as well as to track and manage software development projects. GitHub provides version control using Git, a version control system that allows developers to track changes to their codebase and collaborate with other developers on the same codebase. It also includes a range of features such as bug tracking, project management, and team communication tools. In addition to being a platform for software development, GitHub is also a community of developers and a marketplace for buying and selling software development services.

In this course we are going to extensively use GITHUB functionalities. So create an account now with your personal account. Use a meaningful username. Avoid names that hard to associate with you. If you have a educational email or student id, apply for the Github Student Pack, so you will have access to lots of free tools.

It is nice to have git in your machine, but it is not required, because we are going to use gui via gui tools. See GitKraken below.

GitKraken ¶

GitKraken is a Git client for Windows, Mac, and Linux that provides a graphical interface for working with Git repositories. It allows users to manage Git repositories, create and review changes to code, and collaborate with other developers. Some features of GitKraken include a visual representation of the repository's commit history, the ability to stage and discard changes, and support for popular version control systems like GitHub and GitLab. GitKraken is designed to be user-friendly and to make it easier for developers to work with Git, particularly for those who may be new to version control systems.

Gitkraken is a paid software, and it is free for public repositories, but you can have all enterprise and premium functionalities enabled for free with the student pack and described before.

Install Gitkraken. If you login into gitkraken using GitHub with student pack it will unlock all pro features.

Compiler¶

A compiler is a type of computer program that translates source code into machine instructions that can be run or the CPU or interpreted in a Virtual Machine.

graph TD
  SRC[Source Code] --> |Assembly| OBJ[Machine Code];
  OBJ --> EXE[Executable];
  OBJ --> LIB[Library];

• Source Code in C++, is associated to two different type of textual file extensions: .cpp for sources and .h for header files. It is what the developer writes.
• Assembly is a human readable representation of the Machine Code. It is not the Machine Code itself, but it is a representation of it. It is a way to make the Machine Code human readable.
• Machine Code is what the CPU can run and understand. It is a sequence of 0 and 1 that the CPU can understand and execute. It is not human readable.
• Executable is the result of the compilation process. It is a file that can be executed by the Operating System.
• Library is a collection of Machine Code that can be used by other programs.
• Executable and Library Are binary file that contains the Machine Code instructions that the CPU can execute.

Here you can see briefly a small function to square a number in C++ compiled via GCC into a x86-64 assembly. The left side is the Source Code and the right side is the code compiled into a human-readble Assembly. This code still needs links to the Operation System in order to be executed.

Notes on Virtual Machines (VM)¶

Some languages such as Java, C# and others, compile the Source Code into bytecode that runs on top of an abstraction layer called Virtual Machine (VM). The VM is a software that runs on top of the Operating System and it is responsible to translate the bytecode into Machine Code that the CPU can understand. This is a way to make the Source Code portable across different Operating Systems and CPU architectures - cross-platform. But this abstraction layer has it cost and it is not as efficient as the Machine Code itself.

To speed up the execution, some VM can Just In Time (JIT) compile the bytecode into Machine Code at runtime when the VM detects parts of Source Code is running a lot(Hotspots), to speed up the execution. When this optmization step is happening, the machine is warming up.

graph TD
  SRC[Source Code] --> |Compiles| BYT[Bytecode];
  BYT --> |JIT Compiler| CPU[Machine Code];

Notes on Interpreters¶

Some languages such as Python, Javascript and others, do not compile the Source Code, instead, they run on top a program called Interpreter that reads the Source Code and executes it line by line.

graph TD
  SRC[Source Code] --> |read line| INT[Interpreter];
  INT --> |translates| CPU[Machine Code];

Some Interpreters are Ahead Of Time (AOT) and they compile the Source Code into Machine Code before the Source Code is executed.

graph TD
  SRC[Source Code] --> |AoT compile| INT[Bytecode / Machine Code];
  INT --> CPU;

Platform specific¶

This where things get tricky, C++ compiles the code into a binary that runs directly on the processor and interacts with the operating system. So we can have multiple combinations here. Most compilers are cross-platform, but there is exceptions. And to worsen it, some Compilers are tightly coupled with some IDEs(see below, next item).

I personally prefer to use CLang to be my target because it is the one that is most reliable cross-platform compiler. Which means the code will work as expected in most of the scenarios, the feature support table is the same across all platforms. But GCC is the more bleeding edge, which means usually it is the first to support all new fancy features C++ introduces.

No need to download anything here. We are going to use the CLion IDE. See below topics.

CMake¶

CMake CMake is a cross-platform free and open-source software tool for managing the build process of software using a compiler-independent method. It is designed to support directory hierarchies and applications that depend on multiple libraries. It is used to control the software compilation process using simple platform and compiler independent configuration files, and generate native makefiles and workspaces that can be used in the compiler environment of your choice.

CMake is typically used in conjunction with native build environments such as Make, Ninja, or Visual Studio. It can also generate project files for IDEs such as Xcode and Visual Studio. You can see a full list of supported generators here.

Here is a simple example of a CMakeLists.txt file that can be used to build a program called "myproject" that consists of a single source file called "main.cpp":

# Set minimum version of CMake that can be used
cmake_minimum_required(VERSION 3.10)
# Set the project name
project(myproject)
# Add executable named "myproject" to be built from the source "main.cpp"
add_executable(myproject main.cpp)

cmake_minimum_required(VERSION 3.10)
project(myproject)
add_executable(myexecutable1 main1.cpp)
add_executable(myexecutable2 main2.cpp)

If you want to build via command line this project, you would first generate a build directory, and then run CMake to build the files using the detected compiler or IDE:

cmake -S. -Bbuild
cmake --build build -j20

This will create a Makefile or a Visual Studio solution file in the build directory, depending on your platform and compiler. You can then use the native build tools to build the project by running "make" or opening the solution file in Visual Studio.

CMake provides many options and variables that can be used to customize the build process, such as setting compiler flags, specifying dependencies, and configuring installation targets. You can learn more about CMake by reading the documentation at https://cmake.org/.

IDE¶

An integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE typically integrates a source code editor, build automation tools, and a debugger. Some IDEs also include additional tools, such as a version control system, a class browser, and a support for literate programming. IDEs are designed to maximize programmer productivity by providing tight-knit components with similar user interfaces. This can be achieved through features such as auto-complete, syntax highlighting, and code refactoring. Many IDEs also provide a code debugger, which allows the programmer to step through code execution and find and fix errors. Some examples of popular IDEs include Eclipse, NetBeans, Visual Studio, and Xcode. Each of these IDEs has its own set of features and capabilities, and developers may choose one based on their specific needs and preferences.

In this course, it is strongly suggested to use an IDE in order to achieve higher quality of deliveries, a good IDE effectively flatten the C++ learning curve. You can opt out and use everything by hand, of course, and it will deepen your knowledge on how things work but be assured it can slow down your learning process. Given this course is result oriented, it is not recommended to not use an IDE here. So use one.

OPINION: The most pervasive C++ IDE is CLion and this the one I am going to use. If you use it too, it would be easier to follow my recorded videos. It works on all platforms Windows, Linux and Mac. I recommend downloading it via Jetbrains Toolbox. If you are a student, apply for student pack for free here. On Windows, CLion embeds a GCC compiler or optionally can use visual studio, while on Macs it requires the xcode command line tools, and on Linux, uses GCC from the system installation.

The other options I suggest are:

On all platforms¶

REPLIT - an online and real-time multiplayer IDE. It is slow and lack many functionalities, but can be used for small scoped activities or work with a friend.

VSCode - a small and highly modularized code editor, it have lots of extensions, but it can be complex to set up everything needed: git, cmake, compiler and other stuff.

On Windows:¶

Visual Studio - mostly for Windows. When installing, mark C++ development AND search and install additional tools "CMake". Otherwise, this repo won't work smoothly for you.

DevC++ - an outdated and small IDE. Lacks lots of functionalities, but if you don't have HD space or use an old machine, this can be your option. In long term, this choice would be bad for you for the lack of functionalities. It is better to use REPLIT than this tool, in my opinion.

On OSX¶

XCode - for OSX and Apple devices. It is required at least to have the Command Line Tools. CLion on Macs depends on that.

Xcode Command Line Tools is a small suite of software development tools that are installed on your Mac along with Xcode. These tools include the GCC compiler, which is used to compile C and C++ programs, as well as other tools such as Make and GDB, which are used for debugging and development. The Xcode Command Line Tools are necessary for working with projects from the command line, as well as for using certain software development tools such as Homebrew.

To install the Xcode Command Line Tools, you need to have Xcode installed on your Mac. To check if Xcode is already installed, open a Terminal window and type:

xcode-select -p

If Xcode is already installed, this command will print the path to the Xcode developer directory. If Xcode is not installed, you will see a message saying "xcode-select: error: command line tools are not installed, use xcode-select --install to install."

To install the Xcode Command Line Tools, open a Terminal window and type:

xcode-select --install

This will open a window that prompts you to install the Xcode Command Line Tools. Follow the prompts to complete the installation.

Once the Xcode Command Line Tools are installed, you can use them from the command line by typing commands such as gcc, make, and gdb. You can also use them to install and manage software packages with tools like Homebrew.

On Linux¶

If you are using Linux, you know the drill. No need for further explanations here, you are ahead of the others.

If you are using an Ubuntu distro, you can try this to install most of the tools you will need here:

  sudo apt-get update && sudo apt-get install -y build-essential git cmake lcov xcb libx11-dev libx11-xcb-dev libxcb-randr0-dev

In order to compile:

g++ inputFile.cpp -o executableName

Where g++ is the compiler frontend program to compile your C++ source code; inputFile.cpp is the filename you want to compile, you can pass multiple files here separated by spaces ex.: inputFile1.cpp inputFile2.cpp; -o means the next text will be the output program name where the executable will be built, (for windows, the name should end with .exe ex.: program.exe).

You will have a plethora of editors and IDEs. The one I can suggest is the VSCode, Code::Blocks or KDevelop. But I really prefer CLion.

CLion project workflow with CMake¶

When you create a new project, select New C++ Executable, set the C++ Standard to the newest one, C++20 is enough, and place in a folder location where you prefer.

CLion automatically generate 2 files for you. - CMakeLists.txt is the CMake multiplatform project descriptor, with that, you can share your project with colleagues that are using different platforms than you. - main.cpp is the entry point for your code.

It is not the moment to talk about multiple file projects, but if you want to get ready for it, you will have to edit the CMakeLists.txt file and add them in the add_executable function.

Hello World¶

Hello World

// this a single line comment and it is not compiled. comments are used to explain the code.
// you can do single line comment by adding // in front of the line or
// you can do multi line comments by wrapping your comment in /* and */ such as: /* insert comment here */
/* this is
 * a multi line
 * comment
 */
#include <iostream> // this includes an external library used to deal with console input and output

using namespace std; // we declare that we are going to use the namespace std of the library we just included 

// "int" means it should return an integer number in the end of its execution to communicate if it finished properly
// "main()" function where the operating system will look for starting the code.
// "()" empty parameters. this main function here needs no parameter to execute
// anynthing between { and } is considered a scope. 
// everything stack allocated in this scope will be deallocated in the end of the scope. ex.: local variables. 
int main() {
    /* "cout" means console output. Print to the console the content of what is passed after the 
     * "<<" stream operator. Streams what in the wright side of it to the cout object
     * "endl" means end line. Append a new line to the stream, in the case, console output.
     */
    cout << "Hello World" << endl;

    /* tells the operating system the program finished without errors. Any number different from that is considered 
     * a error code or error number.
     */
    return 0; 
}

Hello Username¶

#include <iostream>
#include <string> // structure to deal with a char sequence, it is called string
using namespace std;
int main(){
    // invites the user to write something
    cout << "Type your name: " << endl;

    /* * string means the type of the variable, this definition came from the string include
     * username means the name of the variable, the container to hold and store the data
     */
    string username;
    /*
     * cin mean console input. It captures data from the console.
     * note the opposite direction of the stream operator. it streams what come from the cin object to the variable.
     */
    cin >> username;
    // example of how to stream and concatenate texts to the console output;
    cout << "Hello " << username << endl;
}

Common Bugs¶

1. Syntax error¶

Syntax errors in C++ are usually caused by mistakes in the source code that prevent the compiler from being able to understand it. Some common causes of syntax errors include: 1. Omitting a required component of a statement, such as a semicolon at the end of a line or a closing curly brace. 2. Using incorrect capitalization or spelling in a keyword or identifier. 3. Using the wrong punctuation, such as using a comma instead of a semicolon. 4. Mixing up the order of operations, such as using an operator that expects two operands before the operands have been provided.

To fix a syntax error, you will need to locate the source of the error and correct it in the code. This can often be a challenging task, as syntax errors can be caused by a variety of factors, and it is not always immediately clear what the problem is. However, there are a few tools that can help you locate and fix syntax errors in your C++ code: 1. A compiler error message: When you try to compile your code, the compiler will often provide an error message that can help you locate the source of the syntax error. These error messages can be somewhat cryptic, but they usually include the line number and a brief description of the problem. 2. A text editor with syntax highlighting: Many text editors, such as Visual Studio or Eclipse, include syntax highlighting, which can help you identify syntax errors by coloring different parts of the code differently. For example, keywords may be highlighted in blue, while variables may be highlighted in green. 3. A debugger: A debugger is a tool that allows you to step through your code line by line, examining the values of variables and the state of the program at each step. This can be a very useful tool for tracking down syntax errors, as it allows you to see exactly where the error occurs and what caused it.

Reference

2. Logic Error¶

A logic error in C++ is an error that occurs when the code produces unintended results or behaves in unexpected ways due to a mistake in the logic of the program. This type of error is usually caused by a coding mistake, such as using the wrong operator, omitting a necessary statement, or using the wrong variable. Here are some common causes of logic errors in C++:

• Incorrect use of conditional statements (e.g., using the wrong comparison operator or forgetting to include a necessary else clause)
• Mistakenly using the assignment operator (=) instead of the equality operator (==) in a conditional statement
• Omitting a necessary loop iteration or failing to terminate a loop at the appropriate time
• Using the wrong variable or array index
• Incorrectly calling a function or passing the wrong arguments to a function

To fix a logic error in C++, you will need to carefully examine your code and identify the mistake. It may be helpful to use a debugger to step through your code and see how it is executing, or to add print statements to help you understand what is happening at each step.

Reference

3. Run-time error¶

A runtime error in C++ means that there is an error in your program that is causing it to behave unexpectedly or crash during runtime, i.e., after you have compiled and run the program. There are many possible causes of runtime errors in C++, including:

• Dereferencing a null pointer
• Accessing an array out of bounds
• Using an uninitialized variable
• Trying to divide by zero
• Attempting to use an object that has been deleted or has gone out of scope

To troubleshoot a runtime error, you'll need to identify the source of the error by examining the error message and the code that is causing the error. Some common tools and techniques you can use to troubleshoot runtime errors include:

• Using a debugger to step through your code line by line
• Printing out the values of variables to see where the error might be occurring
• Adding additional debug statements or logging to your code to help identify the source of the error

It's also a good idea to ensure that you have compiled your code with debugging symbols enabled, as this will allow you to use the debugger to get a better understanding of what is happening in your code. will cause the program to crash during run-time

Reference

Exercises:¶

• Research and read about other notable errors: segmentation fault, stack overflow, buffer overflow.
• Hello World - just print hello world.

Homework¶

1. Setup your environment for your needs following the choices given above. If you are unsure, use CLion and you will be mostly safe.
2. Fork this repo privately. You will have to do your assignments there. Go to the home repo and hit fork.
3. Clone this repo to your machine. gitkraken + github gitkraken clone gitkraken big tutorial
4. Make sure the CMake option "ENABLE_INTRO" is set as ON in CMakeLists.txt file in the root directory in order to see and enable all activities.
5. (enrolled students) If you are enrolled in a class with me, share your repo with me, so I can track your evolution. And do the activities described there.
6. (optional) star this repo :-)

Troubleshooting¶

If you have problems here, start a discussion this is publicly visible and not FERPA compliant. Use discussions in Canvas if you are enrolled in a class with me.