The GNU Compiler Collection (GCC) is a widely used compiler system that supports various programming languages, including C and C++. Within the GCC suite, two prominent compiler drivers are gcc and g++. While they share many similarities, there are key differences in their default behaviors and usage scenarios. In this tutorial, we will delve into the distinctions between gcc and g++, exploring their characteristics, use cases, and implications for C and C++ development.
Introduction to GCC and G++
gcc is often referred to as the GNU C Compiler, although it has evolved into a multi-language compiler collection. The term gcc can still refer specifically to the GNU C Compiler in the context of C programming. On the other hand, g++ is explicitly the C++ compiler frontend for the GNU Compiler Collection.
Default Behaviors and Options
A crucial difference between gcc and g++ lies in their default behaviors and the options they enable by default. When compiling C++ programs with gcc, it does not automatically link against the C++ standard library, whereas g++ does. This means that if you use gcc to compile a C++ program, you need to explicitly specify the -lstdc++ option to link against the C++ standard library.
Additionally, g++ treats files with .c, .h, and .i extensions as C++ source files unless the -x option is used to override this behavior. In contrast, gcc compiles these files as C by default.
Compiler Options and Macros
The choice between gcc and g++ also affects the predefined macros available during compilation. When compiling C files with gcc, fewer predefined macros are available compared to compiling C++ files with either gcc or g++. For example, when compiling .cpp files, additional macros such as __GXX_WEAK__, __cplusplus, and __EXCEPTIONS are defined.
Choosing Between GCC and G++
For general C++ development, it is recommended to use g++ due to its default behavior aligning closely with the needs of C++ programming. While it is technically possible to use gcc for C++ development by specifying appropriate options, using g++ simplifies the compilation process and ensures that the necessary libraries are linked automatically.
However, when working on projects that involve both C and C++ code, understanding the differences between gcc and g++ becomes crucial. In such cases, choosing the right compiler driver can affect not only the compilation process but also the performance and compatibility of the resulting binaries.
Example Usage
To illustrate the difference in practice, consider compiling a simple C++ program named example.cpp:
# Compile example.cpp using g++
g++ -o example example.cpp
# Compile example.cpp using gcc (requires explicit library linking)
gcc -o example example.cpp -lstdc++
In this example, g++ automatically links against the C++ standard library, whereas gcc requires the -lstdc++ option to achieve the same result.
Conclusion
In conclusion, while both gcc and g++ are part of the GNU Compiler Collection, they serve different purposes due to their default behaviors and the options they enable. Understanding these differences is essential for effective C and C++ development, allowing developers to choose the most appropriate compiler driver for their projects and ensure seamless compilation and linking processes.