Gcc

GCC, the GNU Compiler Collection, is a set of compilers used to build software on Linux. The familiar gcc and g++ commands handle C and C++; the collection also has front ends for Fortran, Ada, Go, D, Objective-C, and other languages. Which ones you can use depends on the packages or build you install.

What GCC helps you do

GCC can take a project through preprocessing, compilation, assembly, and linking. You can stop at an intermediate step to produce an object file or let it create an executable. That makes it useful for a small program as well as for projects driven by a build system.

Its shared optimizers and processor back ends are the less visible part of the collection. Optimization settings let developers balance build time, code size, runtime performance, and ease of debugging. Link-time optimization can use information across compiled files, while target-specific options control the processor or ABI a program is built for. Higher optimization settings are not automatically better for every project.

Warnings such as -Wall and -Wextra help flag suspicious code while it is being built. For deeper investigation, GCC can instrument a program with checks such as AddressSanitizer and UndefinedBehaviorSanitizer. These options are useful during development and testing, though they do not replace tests or careful review.

What changed in recent major versions

GCC releases add language features, diagnostics, and support for newer processors. For Linux developers, the biggest recent changes are in the language modes and build options:

• GCC 13 added a Modula-2 front end, more C23 and C++23 features, and SARIF output for compiler diagnostics. SARIF makes warnings easier to feed into code analysis tools.
• GCC 14 introduced -fhardened, which enables a set of security hardening options. It also added more C23 features, the -std=c23 spelling, and early C++26 support.
• GCC 15 changed the default C mode from GNU C17 to GNU C23. Existing C projects may need source updates or an explicit -std= setting when upgrading. This release also added the gcobol COBOL front end, with limited architecture support.
• GCC 16 changed the default C++ mode from GNU C++17 to GNU C++20, so older C++ builds may also need an explicit standard setting. It expanded C++26 support, including opt-in reflection, and added an experimental Algol 68 front end. C++20 modules remain experimental.

Using GCC on Linux

For most Linux projects, start with the compiler packages provided by your distribution. Add the language front end, libraries, and build tools the project requires; installing the C compiler does not necessarily install every part of GCC. A cross compiler must be configured for the intended target. Building GCC itself from source is mainly useful when you need a custom compiler or target setup.

Strengths and things to consider

GCC covers multiple languages and processor families within one compiler collection. Its diagnostics and build options give developers detailed control, especially when a project expects the GNU toolchain. That flexibility also means flags and toolchain versions matter: builds can behave differently when these settings change.