Intel C/C++ compiler (lang/icc) to build the kernel.
The icc CPUTYPE CFLAGS use icc v7 syntax, icc v8 moans about them, but
doesn't abort. They also produce CPU specific code (new instructions
of the CPU, not only CPU specific scheduling), so if you get coredumps
with signal 4 (SIGILL, illegal instruction) you've used the wrong
CPUTYPE.
Incarnations of this patch survive gcc compiles and my make universe.
I use it on my desktop.
To use it update share/mk, add
/usr/local/intel/compiler70/ia32/bin (icc v7, works)
or
/usr/local/intel_cc_80/bin (icc v8, doesn't work)
to your PATH, make sure you have a new kernel compile directory
(e.g. MYKERNEL_icc) and run
CFLAGS="-O2 -ip" CC=icc make depend
CFLAGS="-O2 -ip" CC=icc make
in it.
Don't compile with -ipo, the build infrastructure uses ld directly to
link the kernel and the modules, but -ipo needs the link step to be
performed with Intel's linker.
Problems with icc v8:
- panic: npx0 cannot be emulated on an SMP system
- UP: first start of /bin/sh results in a FP exception
Parts of this commit contains suggestions or submissions from
Marius Strobl <marius@alchemy.franken.de>.
Reviewed by: silence on -arch
Submitted by: netchild
uses alloca() and alloca is impossible to implement as a callable function
on amd64. It has to be a compiler builtin. Note that the bigger problem
is that libc is not c99 clean internally.
in which the source code is written. This is controlled by the CSTD
variable, which can have one of the following values:
- "k&r" => -traditional
- "c89" or "c90" => -std=iso9899:1990
- "c94" or "c95" => -std=iso9899:199409
- "c99" => -std=iso9899:1999
The corresponding option is added to CFLAGS regardless of WARNS level.
This also removes -ansi from WARNS level 6, but adds -Wno-long-long to
work around a weird gcc bug (-ansi, which is supposedly equivalent to
-std=iso9899:1990, seems to turn long long warnings off instead of on)
If CSTD is undefined, CFLAGS are unchanged except for the -ansi /
-Wno-long-long change mentioned above for WARNS level 6.
FreeBSD. This method attempts to centralize all the necessary hacks
or work arounds in one of two places in the tree (src/Makefile.inc1
and src/tools/build). We build a small compatibility library
(libbuild.a) as well as selectively installing necessary include
files. We then include this directory when building host binaries.
This removes all the past release compatibilty hacks from various
places in the tree. We still build on tip of stable and current. I
will work with those that want to support more, although I anticipate
it will just work.
Many thanks to ru@, obrien@ and jhb@ for providing valuable input at
various stage of implementation, as well as for working together to
positively effect a change for the better.
glibc which is externally maintained, so GCC ships with these
warnings turned off by default. This is also consistent with
the src/contrib/gcc/c-lex.c,v 1.2 change.
have the __FBSDID() macro in <sys/cdefs.h>. Fix this once and for all
for tools that need to be bootstrapped.
PR: bin/36747
MFC after: 3 days
Prodded by: obrien
to avoid polluting sys.mk. This directive controls the addition of
compiler warning flags to CFLAGS in a relatively compiler-neutral manner.
The idea is that WARNS can be set in Makefile.inc or in individual
Makefiles as they become clean, to prevent the introduction of new
warnings in the code. -Werror is added by default
