GNU Compiler Collection

The GNU Compiler Collection (GCC) is a free, open-source compiler system produced by the GNU Project, supporting numerous programming languages including C, C++, Objective-C, Fortran, Ada, Go, D, and Modula-2. Originally developed by Richard Stallman in 1987 as the GNU C Compiler, GCC has been maintained by the GCC Steering Committee and a global community of contributors for over 35 years, serving as the default compiler for most Linux distributions, FreeBSD, and embedded systems worldwide. GCC consists of language-specific front-ends (cc1 for C, cc1plus for C++, cc1obj for Objective-C, f951 for Fortran, gnat1 for Ada, and gccgo for Go) that parse source code into a common intermediate representation called GIMPLE (a high-level, tree-based SSA form), a language-independent middle-end that performs optimization passes on GIMPLE (including constant propagation, dead code elimination, loop optimization, vectorization, interprocedural analysis, and auto-parallelization), and target-specific back-ends that lower GIMPLE to RTL (Register Transfer Language) and then generate machine code for over 60 target architectures including x86, x86-64, ARM, AArch64, MIPS, PowerPC, SPARC, s390x, RISC-V, and many embedded processors. GCC supports multiple language standards: C89/C90, C99, C11, C17, C2x (draft), C++98, C++03, C++11, C++14, C++17, C++20, C++23 (partial), and Fortran 77/90/95/2003/2008/2018. Key features include: extensive warning and error diagnostics, link-time optimization (LTO), profile-guided optimization (PGO), sanitizer support (ASan, UBSan, TSan, MSan), OpenMP and OpenACC parallel programming support, and plugin architecture.