GCC 3.0: The State of the Source

The GNU Compiler Collection (GCC) is the most fundamental component of the GNU/Linux devel oper's toolchest. GCC, like the Linux kernel and the X windowing system, is a complex but important part of the GNU/Linux operating system. In fact, both the kernel and X are built with GCC, so, to a large extent, the speed and correctness of the entire system depends on GCC. The next major release of GCC, GCC 3.0, will be released sometime late this year. This release of GCC will contain a number of features of considerable import to the community. In addition, the quality assurance processes for this release will be more stringent than in any previous release. There fore, GCC 3.0 will likely be a more reliable compiler, and will be more capable of supporting the needs of an ever-expanding developer community, than previous releases of GCC. Principal among the improvements will be a new, stable, industry-standard C++ application binary interface (ABI). This new C++ ABI will provide, for the first time, an assurance that C++ programs compiled with one version of G++ can be linked with C++ libraries compiled with a different version of G++, and, in fact, with libraries compiled with other compilers. In addition, GCC 3.0 will contain much improved support for Java, a number of new optimizations and bug fixes, improvements in compile-time performance, and new infrastructure to support future optimization and enhancement. Because much of our work has focused on the C++ front-end, this paper will focus on C++-related work. That orientation should not be construed as implying that the other improvements in GCC 3.0 are less important. While a perhaps disproportionate amount of this paper focuses on the C++ ABI, we have attempted to describe, in somewhat less detail, some of the other highlights of the upcoming release.