Messages in this thread |  | | From | Arnd Bergmann <> | Date | Wed, 10 May 2017 09:58:13 +0200 | Subject | Re: Updating kernel.org cross compilers? |
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On Wed, May 10, 2017 at 12:18 AM, Segher Boessenkool <segher@kernel.crashing.org> wrote: > On Tue, May 09, 2017 at 03:59:27PM +0100, Andre Przywara wrote: >> >> I was able to build (bare-metal) toolchains for >> >> all architectures except arc, m68k, tilegx and tilepro. >> > >> > arc needs a more recent GCC; the other probably as well. GCC 7 should >> > be out very soon, you probably want to wait for that :-) >> >> Well, GCC 7 indeed builds better, but then again is a very new compiler. >> For instance in the moment it spits a lot of warnings when compiling the >> kernel (mostly due to some *printf analysis). It's not hard to fix, but >> this will take a while to trickle in and it's questionable whether this >> will be backported everywhere. >> So in addition to GCC 7.1 I'd like to have at least GCC 6.3 around, >> which builds kernels without warnings today. > > If you don't want warnings, turn off the warnings or just don't look at > them... or fix the problems? Many of the new warnings point out actual > problems. > > Many of those sprintf problems in the kernel have already been fixed.
I've been using gcc-7.0 for a long time and fixed a lot of bugs it found, along with more harmless warnings, but I had disabled a couple of warning options when I first installed gcc-7 and ended up ignoring those.
The exact set of additional options I used is:
-Wimplicit-fallthrough=0 -Wno-duplicate-decl-specifier -Wno-int-in-bool-context -Wno-bool-operation -Wno-format-truncation -Wno-format-overflow
there were a couple of others that I sent kernel fixes for instead. I should probably revisit that list and for each of them either only enable it with "make W=1" or fix all known warnings. In the long run, I'd actually hope to fix all W=1 warnings too and enable them by default.
Arnd
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