1.. SPDX-License-Identifier: GPL-2.0-only 2 3========================== 4Bash completion for Kbuild 5========================== 6 7The kernel build system is written using Makefiles, and Bash completion 8for the `make` command is available through the `bash-completion`_ project. 9 10However, the Makefiles for the kernel build are complex. The generic completion 11rules for the `make` command do not provide meaningful suggestions for the 12kernel build system, except for the options of the `make` command itself. 13 14To enhance completion for various variables and targets, the kernel source 15includes its own completion script at `scripts/bash-completion/make`. 16 17This script provides additional completions when working within the kernel tree. 18Outside the kernel tree, it defaults to the generic completion rules for the 19`make` command. 20 21Prerequisites 22============= 23 24The script relies on helper functions provided by `bash-completion`_ project. 25Please ensure it is installed on your system. On most distributions, you can 26install the `bash-completion` package through the standard package manager. 27 28How to use 29========== 30 31You can source the script directly:: 32 33 $ source scripts/bash-completion/make 34 35Or, you can copy it into the search path for Bash completion scripts. 36For example:: 37 38 $ mkdir -p ~/.local/share/bash-completion/completions 39 $ cp scripts/bash-completion/make ~/.local/share/bash-completion/completions/ 40 41Details 42======= 43 44The additional completion for Kbuild is enabled in the following cases: 45 46 - You are in the root directory of the kernel source. 47 - You are in the top-level build directory created by the O= option 48 (checked via the `source` symlink pointing to the kernel source). 49 - The -C make option specifies the kernel source or build directory. 50 - The -f make option specifies a file in the kernel source or build directory. 51 52If none of the above are met, it falls back to the generic completion rules. 53 54The completion supports: 55 56 - Commonly used targets, such as `all`, `menuconfig`, `dtbs`, etc. 57 - Make (or environment) variables, such as `ARCH`, `LLVM`, etc. 58 - Single-target builds (`foo/bar/baz.o`) 59 - Configuration files (`*_defconfig` and `*.config`) 60 61Some variables offer intelligent behavior. For instance, `CROSS_COMPILE=` 62followed by a TAB displays installed toolchains. The list of defconfig files 63shown depends on the value of the `ARCH=` variable. 64 65.. _bash-completion: https://github.com/scop/bash-completion/ 66