Developer(s) | GNU Project |
---|---|
Stable release |
2.29.1 / September 25, 2017
|
Written in | C |
Platform | Cross-platform |
Type | Assembler |
License | GNU General Public License v3 |
Website | www |
The GNU Assembler, commonly known as gas or simply as, its executable name, is the assembler used by the GNU Project. It is the default back-end of GCC. It is used to assemble the GNU operating system and the Linux kernel, and various other software. It is a part of the GNU Binutils package. It was announced in 1986.
The GAS executable is named as, the standard name for a Unix assembler. GAS is cross-platform, and both runs on and assembles for a number of different computer architectures. Released under the GNU General Public License v3, GAS is free software.
GAS supports a general syntax that works for all of the supported architectures. The general syntax includes assembler directives and a method for commenting.
GAS uses assembler directives (also known as pseudo ops), which are keywords beginning with a period that behave similarly to preprocessor directives in the C programming language. While most of the available assembler directives are valid regardless of the target architecture, some directives are machine dependent.
GAS supports two comment styles:
As in C multi-line comments start and end with mirroring slash-asterisk pairs:
Single line comments have a few different formats varying on which architecture is being assembled for.
Being the back-end for a popular compiler suite, namely GCC, the GNU Assembler is very widely used in compiling modern open source software. GAS is often used as the assembler on GNU/Linux operating systems in conjunction with other GNU software. A modified version of GAS can also be found in the Macintosh operating system's development tools package since macOS.