b339ec9c22
The cross-product of the kernel's supported toolchains, architectures, and configuration options is large. So large, that it's generally accepted to be infeasible to enumerate and build+test them all (many compile-testers rely on randomly generated configs). Without the possibility to enumerate all possible combinations of toolchains, architectures, and configuration options, it is inevitable that compiler warnings in this space exist. With -Werror, this means that an innumerable set of kernels are now broken, yet had been perfectly usable before (confused compilers, code with warnings unused, or luck). Distributors will necessarily pick a point in the toolchain X arch X config space, and if unlucky, will have a broken build. Granted, those will likely disable CONFIG_WERROR and move on. The kernel's default configuration is unlikely to be suitable for all users, but it's inappropriate to force many users to set CONFIG_WERROR=n. This also holds for CI systems which are focused on runtime testing, where the odd warning in some subsystem will disrupt testing of the rest of the kernel. Many of those runtime-focused CI systems run tests or fuzz the kernel using runtime debugging tools. Runtime testing of different subsystems can proceed in parallel, and potentially uncover serious bugs; halting runtime testing of the entire kernel because of the odd warning (now error) in a subsystem or driver is simply inappropriate. Therefore, runtime-focused CI systems will likely choose CONFIG_WERROR=n as well. The appropriate usecase for -Werror is therefore compile-test focused builds (often done by developers or CI systems). Reflect this in the Kconfig option by making the default value of WERROR match COMPILE_TEST. Signed-off-by: Marco Elver <elver@google.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> Reviwed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.