stages (build-tools, cross-tools, etc) of the build, so we can detect in
bsd.*.mk whether to pass compiler-specific flags to ${CC}.
In particular, this commit will allow using WITH_CLANG_IS_CC when the
base compiler is still gcc, and when ${CC}, ${CXX} and ${CPP} are left
at their defaults. The early stages will then be built using gcc, and
no clang-specific flags will be passed to it. The later stages will be
built as usual.
The EARLY_BUILD define can also serve other uses, such as building the
world stage C++ executables with libc++ instead of libstdc++: during the
early build stages, we cannot assume libc++ is already available, so we
must still build with libstdc++ at that time.
MFC after: 1 week
that it is better to error out when people attempt to build using the
wrong bsd.*.mk files, than to silently ignore the problem.
This means, that after this commit, if you want to build kernel modules
by hand (or via a port) from a head source tree, you *must* make sure
the files in /usr/share/mk are in sync with that tree. If that isn't
possible, for example when you are running on an older FreeBSD branch,
you can:
- Run "make buildenv" from your head source tree, to have the correct
environment setup. (It's advisable to have run "make buildworld", or
at a minimum "make toolchain" first.)
- Alternatively, set MAKESYSPATH to the share/mk directory under your
head source tree. If your build tools are too old, other problems may
still occur.
- Alternatively, use "make -m" and specify the share/mk directory under
your head source tree. Again, build tools that are too old may still
result in trouble.
MFC after: 2 weeks
kernel modules using their old installed /usr/share/mk/bsd.*.mk files,
instead of the updated ones in their source tree. This leads to errors
like:
"sys/conf/kmod.mk", line 111: Malformed conditional (${MK_CLANG_IS_CC} == "no" && ${CC:T:Mclang} != "clang")
Obviously, these errors will go away after a "make installworld", or
alternatively, by using "make buildenv" before attempting to manually
build modules.
However, since it is apparently an expected use case to build using old
.mk files, change the way we test for clang, so it also works when the
MK_CLANG_IS_CC macro doesn't exist.
Note the conditional expressions are becoming rather unreadable now, but
I will attempt to fix that on a followup commit.
MFC after: 2 weeks
installs clang as /usr/bin/cc, /usr/bin/c++ and /usr/bin/cpp.
Note this does *not* disable building and installing gcc, which will
still be available as /usr/bin/gcc, /usr/bin/g++ and /usr/bin/gcpp. If
you want to disable gcc completely, you must use WITHOUT_GCC.
MFC after: 2 weeks
get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.
Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang (disables -Werror)
- NO_WCAST_ALIGN.clang (disables -Wcast-align)
- NO_WFORMAT.clang (disables -Wformat and friends)
- CLANG_NO_IAS (disables integrated assembler)
- CLANG_OPT_SMALL (adds flags for extra small size optimizations)
As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf! For clang, use the following:
CC=clang
CXX=clang++
CPP=clang-cpp
MFC after: 2 weeks
to selectively work around warnings in programs that don't use flexible
array members, but instead define arrays of length 1 at the end of the
struct, and then access those beyond their declared bounds.
MFC after: 1 week
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. ;)
Following the convention of NO_WERROR and NO_WCAST_ALIGN add NO_WFORMAT,
which, when defined in Makefile, turns off compile-time format checking
(by adding -Wno-format), but still allows to use high WARNS level.
MFC after: 2 weeks
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>
NO_WCAST_ALIGN. The headers of the standard C++ library are
not 64-bit clean and trigger the warning. This prevents use
of WARNS>=4 on ia64 for example.
Unfortunately there are two slight problems with that:
- Yacc and lex might generate code that generates warnings because of
this. Require yacc and lex to be rebuilt during bootstrap. I'm not
incrementing __FreeBSD_version here, because I assume someone else
will do this eventually.
- When running `make buildkernel', it uses share/mk from the source
treeo to build aicasm. Because aicasm also depends on lex, this would
break. Lower WARNS to 5 for now. We should just increment it to 6
again somewhere in the very far future.
The segfaults when using SSP seem to be a gcc bug, a patch is available
in the gcc bugzilla, and will be imported once it's committed
into the official gcc tree.
- 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>
This time, change the default CFLAGS to match the simple defaults that
the tinderboxes use. That is, don't use -fno-strict-aliasing by default.
My last attempt to re-anable -Werror gave me a lesson in what strict
aliasing is all about. There was code in libthr that wasn't 64-bit clean.
The default use of -fno-strict-aliasing hid that.
By using -fno-strict-aliasing by default we were choosing to ignore
problems in code which had the potential to shoot ourselves in the
foot. Sometimes it would be the 64-bit foot. I have both feet. The left
ones are 32 bits and the right ones are 64 bits. Don't ask about my
endian orientation. :-)
The -fno-strict-aliasing compiler arg can still be used if NO_STRING_ALIASING
is define in make.
We are early in the FreeBSD 8 development, so we have the opportunity to
wait and see if this works for us. I am sure that people will complain.
We can easily revert this. All I ask is that we take sides: clean code or
not. YMMV.
Note that by using -fno-strict-aliasing the build won't actually break.
Only where WARNS is set (and -Werror is used) will a compiler warning break
the build. The use of WARNS levels implies (to me at least) that the
developer has taken some care to make the code pass basic checks. This
commit makes those checks just a little bit more strict.
obstacle to enabling -Werror. I'll continue to work on cleaning up the
code so that we can keep this enabled.
If the tinderboxes would just use the default CFLAGS set in this file,
all would be fine and we'd be able to make use of -Werror.
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.
There are new warnings that kill the build otherwise.
Disable pointer destination sign mismatch warning alltogether. Our tree
is in no shape to have that enabled yet.
of C in which the program or library is written.
Note that this is *not* intended to be used across the whole tree. It
is intended to be used for individual libraries or programs which use
specific language features which the compiler must know about in order
to produce correct warnings at high WARNS levels.
MFC after: 1 month
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.
