GCC 15 compilers arrive with Rust, C, C++, and Cobol enhancements

GCC (GNU Compiler Collection) 15.1 has arrived with improvements for programming languages ranging from Rust to C to Cobol. GCC 15.1 also brings improvements for vectorization and for compiling very large input files.

Announced April 25 as the first release in the GCC 15 branch, GCC 15.1 is described by GCC developers as a major release. Among the highlights, compile time for large input files with -Wmisleading-indentation has been significantly improved, according to the GCC team. The compiler now can track column numbers larger than 4,096, and very large source files have more accurate location reporting.

In another improvement in the release, the vectorizer now supports vectorizing loops with early exits where the number of elements for the input pointers are unknown through peeling for alignment. This capability is supported for only for loops with fixed vector lengths. GCC 15.1 includes a long list of other changes, such as GCC now emitting diagnostics in multiple formats simultaneously, via the new option -fdiagnostics-add-output=.

In language support, the C compiler now defaults to the C23 standard and fully conforms to it, said Richard Biener, who participates in the development of GCC. Biener cited C’s backing of C23 as likely the most impressive feature of GCC 15.1. New Rust accommodations include basic inline assembly support being added to the front end, enabling compilation of architecture functions of core 1.49; the addition of support for for loops; and the lowering of the minimum required Rust version to Rust 1.49, thus allowing more systems to compile to the Rust front end. For Cobol, GCC now includes an ISO Cobol compiler, gcobol. And for C++, the GCC front end now implements additional C++26 features such as attributes for structured bindings and variadic friends, along with some missing C++23 features and defect resolutions.

GCC is under the jurisdiction of the Free Software Foundation.