with clang. There are several macros in these files that return values,
and in some cases nothing is done with them, but it is completely
harmless. For some other files, also disable -Wconstant-conversion,
since that triggers a false positive with the DMA_BIT_MASK() macro.
MFC after: 1 week
kernel builds. All the instances of this warning in our tree are
completely harmless, and many people seem to like adding extra
parentheses to make precedence clearer.
MFC after: 1 week
builds. All the instances of this warning in our tree are completely
harmless. (Most of the empty bodies look to be used simply as reminder
for the developer to add something later.)
While here, assign to CWARNEXTRA with ?=, so it can be overridden
easily, if needed.
MFC after: 1 week
CWARNEXTRA variable, which gets included into the initial CWARNFLAGS
setting. This makes it easier to override CWARNFLAGS with completely
custom settings (including enabling any disabled warnings).
Reminded by: arundel
MFC after: 1 week
might be useful in some cases, but which are not severe enough to error
out the whole kernel build. Display them anyway, so there is at least
some incentive to fix them eventually.
Start with -Wtautological-compare warnings. These usually occur when
people check if unsigned quantities are negative, or similar cases. To
clean these up would be painful, and might give problems if the base
type which is compared against changes to signed later on.
MFC after: 1 week
as it gets the following warning:
sys/dev/asr/asr.c:1836:29: warning: array index of '58' indexes past the end of an array (that contains 1 element) [-Warray-bounds]
while ((len > 0) && (sg < &((PPRIVATE_SCSI_SCB_EXECUTE_MESSAGE)
^
sys/dev/asr/i2omsg.h:934:8: note: array 'Simple' declared here
I2O_SGE_SIMPLE_ELEMENT Simple[1];
^
This is a false positive, since I2O_SG_ELEMENT::Simple is not declared
as a C99 flexible array member, but in the old (but more portable) way.
At run-time, the proper number of array elements will hopefully have
been allocated.
MFC after: 1 week
there are some places in the kernel where fixing them is too disruptive,
or where there is a false positive.
In this case, disable -Wconstant-conversion for two aic7xxx-related
files, as they get the following warning on i386 (and possibly on other
32-bit arches):
sys/dev/aic7xxx/ahc_pci.c:112:10: warning: implicit conversion from 'long long' to 'bus_addr_t' (aka 'unsigned int') changes value from 549755813887 to 4294967295 [-Wconstant-conversion]
? 0x7FFFFFFFFFLL
~~^~~~~~~~~~~~~~
This is a false positive, since the code only passes the 0x7FFFFFFFFFLL
argument, if sizeof(bus_addr_t) is larger than 4 (e.g. on 64 bit arches,
or when PAE is enabled on i386). The code could be refactored to do
compile-time checks, but that is more disruptive.
MFC after: 1 week
- CTFCONVERT_CMD=... is a hack (should be defined to empty string instead):
make(1) should be taught to ignore empty commands silently in compat mode
(as it does in !compat mode, GNU make also silently ignores empty commands)
and to skip printing empty commands in !compat mode
- config(8) should generate ${NORMAL_CTFCONVERT} invocation without '@':
this will allow to simplify kern.pre.mk even more and lessen the number
of shell invocations during kernel build when CTF is turned off
- WITH_CTF can now be converted to usual MK_CTF=yes/no infrastructure
Pointy hat to: fjoe [1]
Alexander Best (arundel@).
For clang, -fdiagnostics-show-option is enabled by default, but for gcc it
isn't. This option will report which -W* flag was responsible for triggering
a certain warning. This will bring gcc warnings closer to the ones clang emits
and might also help developers track down tinderbox failures a bit quicker.
Submitted by: arundel
flags are also specified. This change makes use of this behaviour and removes
unneeded -mno-* flags.
Note that clang does not yet enable AVX support for any CPU. However at some
point in the future it will and since we definitely want to disable it for the
kernel, we might as well add the -mno-avx flag now.
Submitted by: arundel
developers committing new code with broken include directories.
Fix a few whitespace issues.
Improve a couple of comments.
-W is now deprecated and is referred to as -Wextra (see gcc(1)).
Submitted by: arundel
This support has not worked for several years, and is not likely to work
again, unless Intel decides to release a native FreeBSD version of their
compiler. ;)
Makefiles or *.mk files, use ${CC:T:Mfoo} instead, so only the basename
of the compiler command (excluding any arguments) is considered.
This allows you to use, for example, CC="/nondefault/path/clang -xxx",
and still have the various tests in bsd.*.mk identify your compiler as
clang correctly.
ICC if cases were also changed.
Submitted by: Dimitry Andric <dimitry at andric.com>
are some problems with static executables), make.conf (would also
affect ports which do not use GNU make and do not override the
compile targets) or in the kernel config (via "makeoptions
WITH_CTF=yes").
Additional (related) changes:
- propagate WITH_CTF to module builds
- do not add -g to the linker flags, it's a noop there anyway
(at least according to the man page of ld)
- do not add -g to CFLAGS unconditionally
we need to have a look if it is really needed (IMO not) or if there
is a way to add it only when WITH_CTF is used
Note: ctfconvert / ctfmerge lines will not appear in the build output,
to protect the innocent (those which do not build with WITH_CTF would
see the shell-test and may think WITH_CTF is used).
Reviewed by: imp, jhb, scottl (earlier version)
Discussed on: arch@
r201902 | imp | 2010-01-09 10:16:19 -0700 (Sat, 09 Jan 2010) | 2 lines
Fix comment, which was missed in an earlier commit...
r195669 | gonzo | 2009-07-13 17:03:44 -0600 (Mon, 13 Jul 2009) | 3 lines
- Remove -mno-dsp from CFLAGS. MIPS DSP ASE is off by default
now (as it should be)
- It is opt-out for now so as to give it maximum testing, but it may be
turned opt-in for stable branches depending on the consensus. You
can turn it off with WITHOUT_SSP.
- WITHOUT_SSP was previously used to disable the build of GNU libssp.
It is harmless to steal the knob as SSP symbols have been provided
by libc for a long time, GNU libssp should not have been much used.
- SSP is disabled in a few corners such as system bootstrap programs
(sys/boot), process bootstrap code (rtld, csu) and SSP symbols themselves.
- It should be safe to use -fstack-protector-all to build world, however
libc will be automatically downgraded to -fstack-protector because it
breaks rtld otherwise.
- This option is unavailable on ia64.
Enable GCC stack protection (aka Propolice) for kernel:
- It is opt-out for now so as to give it maximum testing.
- Do not compile your kernel with -fstack-protector-all, it won't work.
Submitted by: Jeremie Le Hen <jeremie@le-hen.org>
compiler invocation. This is just to help get over the hump of people
tracking down bugs that may cross the GCC 4.2 upgrade.
It is envisioned that this option goes away after a suitable amount
of time.
Switch ia64 kernels to -fpic. This is likely wrong, but at least gets
ia64 kernels to compile and link with GCC 4.2. The previous -mno-sdata
trick is not working anymore.
`-Wundef'
Warn whenever an identifier which is not a macro is encountered in
an `#if' directive, outside of `defined'. Such identifiers are
replaced with zero.
I think all we really need is -fno-sse2.
I really don't like cluttering up the compiler invocation,
but this bigger hammer will fix reported problems for now.
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
