On Thursday, November 02, 2017, Russell King - ARM Linux wrote:

The compiler is only involved for the C pre-processor front-end.  It's
not involved in parsing the resulting assembly - as far as gcc is
concerned, it could be forth in the post-processed file.

GCC will then pass the post-processed output to binutils 'as' to do the
actual assembly, and that's what should complain.

Oops, I meant to show this:

$ arm-linux-gnueabihf-as -version
GNU assembler (Linaro_Binutils-2017.01) 2.25.2 Linaro 2016_02
Copyright (C) 2014 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or later.
This program has absolutely no warranty.
This assembler was configured for a target of `arm-linux-gnueabihf'.

So, as far as ARM assembly in the Linux kernel goes, all constants must
be preceded by # whether or not binutils requires it - no exceptions.
Please always test assembly changes with a binutils version that is not
gratuitously broken!

Somewhat ironic since Nicolas works for Linaro.


Chris