PowerPC, add lib/Support/Atomic.cpp. This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.
Reported by: Mark Millard
PR: 214902
X-MFC-With: 309124
Use this to control inclusion of the libllvm functionality required
by lld. Enable by default on arm64 and amd64, the two platforms where
lld is most usable for testing.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7713
We might want to generate this file at build time, but for now just
provide a static copy as done with other version files.
Sponsored by: The FreeBSD Foundation
* Bootstrap llvm-tblgen and clang-tblgen with a minimal llvm static
library, that has no other dependencies.
* Roll up all separate llvm libraries into one big static libllvm.
* Similar for all separate clang and lldb static libraries.
* For all these libraries, generate their .inc files only once.
* Link all llvm tools (including extra) against the big libllvm.
* Link clang and clang-format against the big libllvm and libclang.
* Link lldb against the big libllvm, libclang and liblldb.
N.B.: This is work in progress, some details may still be missing.
It also heavily depends on bsd.*.mk's support for SRCS and DPSRCS with
relative pathnames, which apparently does not always work as expected.
For building llvm, clang and lldb though, it seems to work just fine.
The main idea behind this restructuring is maintainability and build
peformance. The previous large number of very small libraries, each
with their own generated files and dependencies was slow to traverse
and hard to understand.
Possible future improvements:
* Only build certain targets, e.g. for most regular users having just
one target will be fine. This will shave off some build time.
* Building the big llvm, clang and lldb libraries as shared (private)
libraries.
* Adding other components from the LLVM project, such as lld.
Fix for pr24346: arm asm label calculation error in sub
Some ARM instructions encode 32-bit immediates as a 8-bit integer
(0-255) and a 4-bit rotation (0-30, even) in its least significant 12
bits. The original fixup, FK_Data_4, patches the instruction by the
value bit-to-bit, regardless of the encoding. For example, assuming
the label L1 and L2 are 0x0 and 0x104 respectively, the following
instruction:
add r0, r0, #(L2 - L1) ; expects 0x104, i.e., 260
would be assembled to the following, which adds 1 to r0, instead of
260:
e2800104 add r0, r0, #4, 2 ; equivalently 1
The new fixup kind fixup_arm_mod_imm takes care of the encoding:
e2800f41 add r0, r0, #260
Patch by Ting-Yuan Huang!
This fixes label calculation for ARM assembly, and is needed to enable
ARM assembly sources for OpenSSL.
Requested by: jkim
MFC after: 3 days
[X86] AMD Bobcat CPU (btver1) doesn't support XSAVE
btver1 is a SSSE3/SSE4a only CPU - it doesn't have AVX and doesn't
support XSAVE.
Differential Revision: http://reviews.llvm.org/D17682
Pull in r262782 from upstream llvm trunk (by Simon Pilgrim):
[X86] AMD Bobcat CPU (btver1) doesn't support XSAVE
btver1 is a SSSE3/SSE4a only CPU - it doesn't have AVX and doesn't
support XSAVE.
Differential Revision: http://reviews.llvm.org/D17683
This ensures clang does not emit AVX instructions for CPUTYPE=btver1.
Reported by: Michel Depeige <demik+freebsd@lostwave.net>
PR: 211864
MFC after: 3 days
file, lib/clang/freebsd_cc_version.h, instead of reusing Version.inc.
The header is only included from one .cpp file in the clang tree.
This minimizes the number of .cpp files that need to be rebuilt if the
version is bumped.
Discussed with: bdrewery
Only attempt to detect AVG if SSE2 is available
Summary:
In PR29973 Sanjay Patel reported an assertion failure when a certain
loop was optimized, for a target without SSE2 support. It turned out
this was because of the AVG pattern detection introduced in rL253952.
Prevent the assertion failure by bailing out early in
`detectAVGPattern()`, if the target does not support SSE2.
Also add a minimized test case.
Reviewers: congh, eli.friedman, spatel
Subscribers: emaste, llvm-commits
Differential Revision: http://reviews.llvm.org/D20905
This should fix assertion failures ("Requires at least SSE2!") when
building the games/0ad port with CPUTYPE=pentium3.
Reported by: madpilot
The WITH_SYSTEM_COMPILER build option will rely on this value to determine what
__FreeBSD_cc_version the source tree will produce. This value will be compared
against the /usr/bin/cc value to determine if a new compiler is needed.
Start with 1100002 which is 1 more than than the value we've had since
3.8.0 to ensure that all changes since then are present.
Reviewed by: dim
Sponsored by: EMC / Isilon Storage Division
As mentioned in the Makefile there's an "atrocious" hack to generate a
different version of Options.inc.h, depending on the library being
built.
Remove the catch-all else case and limit it to specific libraries, so
that we don't accidentally use the Options.inc.h from clangdriver if a
future libary also uses Options.inc.h.
Reviewed by: dim
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6209
At least FAST_DEPEND won't even run 'make depend', so the code was
potentially broken with FAST_DEPEND anyhow. The .dinclude directive
will ignore missing files rather than make them be fatal.
Sponsored by: EMC / Isilon Storage Division
These are no longer needed after the recent 'beforebuild: depend' changes
and hooking DIRDEPS_BUILD into a subset of FAST_DEPEND which supports
skipping 'make depend'.
Sponsored by: EMC / Isilon Storage Division
This will generate dependencies rather than depending on the previous behavior
of depending on the guessed OBJS: *.h dependecies or a user running
'make depend'.
Experimentation showed that depending only on headers was not enough and
prone to .ORDER errors. Downstream users may also have added
dependencies into beforedepend or afterdepend targets. The safest way to
ensure dependencies are generated before build is to run 'make depend'
beforehand rather than just depending on DPSRCS+SRCS.
Note that the OBJS_DEPEND_GUESS mechanism (a.k.a .if !exists(.depend) then
foo.o: *.h) is still useful as it improves incremental builds with missing
.depend.* files and allows 'make foo.o' to usually work, while this
'beforebuild: depend' ensures that the build will always find all dependencies.
The 'make foo.o' case has no means of a 'beforebuild' hook.
This also removes several hacks in the DIRDEPS_BUILD:
- NO_INSTALL_INCLUDES is no longer needed as it mostly was to work around
.ORDER problems with building the needed headers early.
- DIRDEPS_BUILD: It is no longer necesarry to track "local dependencies" in
Makefile.depend.
These were only in Makefile.depend for 'clean builds' since nothing would
generate the files due to skipping 'make depend' and early dependency
bugs that have been fixed, such as adding headers into SRCS for the
OBJS_DEPEND_GUESS mechanism. Normally if a .depend file does not exist then
a dependency is added by bsd.lib.mk/bsd.prog.mk from OBJS: *.h. However,
meta.autodep.mk creates a .depend file from created meta files and inserts
that into Makefile.depend. It also only tracks *.[ch] files though which can
miss some dependencies that are hooked into 'make depend'. This .depend
that is created then breaks incremental builds due to the !exists(.depend)
checks for OBJS_DEPEND_GUESS. The goal was to skip 'make depend' yet it only
really works the first time. After that files are not generated as expected,
which r288966 tried to address but was using buildfiles: rather than
beforebuild: and was reverted in r291725. As noted previously,
depending only on headers in beforebuild: would create .ORDER errors
in some cases.
meta.autodep.mk is still used to generate Makefile.depend though via:
gendirdeps: Makefile.depend
.END: gendirdeps
This commit allows removing all of the "local dependencies" in
Makefile.depend which cuts down on churn and removes some of the
arch-dependent Makefile.depend files.
The "local dependencies" were also problematic for bootstrapping.
Sponsored by: EMC / Isilon Storage Division
linking. These are too large for a branch instruction to branch from an
earlier point in the code to somewhere later.
This will also allow these to be build with Thumb-2 when we get this
infrastructure.
Reviewed by: dim
Differential Revision: https://reviews.freebsd.org/D4855
llvm's LinkAllPasses.h. This caused some of the calls not to be
emitted, if the optimization level was -O2 or higher.
Conversely, if you used -O1 or lower, calls to e.g. RunningOnValgrind()
would be emitted, leading to link failures, because we did not include
Valgrind.cpp into libllvmsupport. Therefore, add it unconditionally.
Noticed by: ian
bugfix-only release, with no new features.
Please note that from 3.5.0 onwards, clang and llvm require C++11
support to build; see UPDATING for more information.
This is not properly respecting WITHOUT or ARCH dependencies in target/.
Doing so requires a massive effort to rework targets/ to do so. A
better approach will be to either include the SUBDIR Makefiles directly
and map to DIRDEPS or just dynamically lookup the SUBDIR. These lose
the benefit of having a userland/lib, userland/libexec, etc, though and
results in a massive package. The current implementation of targets/ is
very unmaintainable.
Currently rescue/rescue and sys/modules are still not connected.
Sponsored by: EMC / Isilon Storage Division
- Support more of the toolchain from TOOLSDIR.
- This also improves 'make bootstrap-tools' to pass, for example,
AS=/usr/bin/as to Makefile.inc1, which will tell cross-tools to use
external toolchain support and avoid building things we won't be using
in the build.
- Always set the PATH to contain the staged TOOLSDIR directories when
not building the bootstrap targets.
The previous version was only setting this at MAKE.LEVEL==0 and if the
TOOLSDIR existed. Both of these prevented using staged tools that were
built during the build though as DIRDEPS with .host dependencies, such
as the fix for needing usr.bin/localedef.host in r291311.
This is not a common tool so we must build and use it during the build,
and need to be prepared to change PATH as soon as it appears.
This should also fix the issue of host dependencies disappearing from
Makefile.depend and then reappearing due to the start of the fresh build not
having the directory yet, resulting in the tools that were built not actually
being used.
- Only use LEGACY_TOOLS while building in Makefile.inc1. After r291317
and r291546 there is no need to add LEGACY_TOOLS into the PATH for
the pseudo/targets/toolchain build.
- Because the pseudo/targets/toolchain will now build its own
[clang-]tblgen, the special logic in clang.build.mk is no longer needed.
- LEGACY_TOOLS is no longer used outside of targets/pseudo/bootstrap-tools
so is no longer passed into the environment in its build.
Sponsored by: EMC / Isilon Storage Division
staged.
None of usr.bin/clang/clang-tblgen or its dependencies need
lib/clang/include, so there is no cyclic dependency here to worry about.
The issue came about because of workarounds to dependencies on clang
being optional.
Without this, the clang-tblgen called during the build would change
after it was staged for the host. This would cause lib/clang/include to
rebuild due to changed build commands.
Sponsored by: EMC / Isilon Storage Division
It was not being used outside of META_MODE but this should make it more clear
that it is only for META_MODE.
Sponsored by: EMC / Isilon Storage Division
the target is "make depend". This works around errors during
incremental make depend of some clang libraries, for example "don't know
how to make contrib/llvm/include/llvm/IR/IntrinsicsR600.td".
Reported by: emaste
Notable upstream commits (upstream revision in parens):
- Add a JSON producer to LLDB (228636)
- Don't crash on bad DWARF expression (228729)
- Add support of DWARFv3 DW_OP_form_tls_address (231342)
- Assembly profiler for MIPS64 (232619)
- Handle FreeBSD/arm64 core files (233273)
- Read/Write register for MIPS64 (233685)
- Rework LLDB system initialization (233758)
- SysV ABI for aarch64 (236098)
- MIPS software single stepping (236696)
- FreeBSD/arm live debugging support (237303)
- Assembly profiler for mips32 (237420)
- Parse function name from DWARF DW_AT_abstract_origin (238307)
- Improve LLDB prompt handling (238313)
- Add real time signals support to FreeBSDSignals (238316)
- Fix race in IOHandlerProcessSTDIO (238423)
- MIPS64 Branch instruction emulation for SW single stepping (238820)
- Improve OSType initialization in elf object file's arch_spec (239148)
- Emulation of MIPS64 floating-point branch instructions (239996)
- ABI Plugin for MIPS32 (239997)
- ABI Plugin for MIPS64 (240123)
- MIPS32 branch emulation and single stepping (240373)
- Improve instruction emulation based stack unwinding on ARM (240533)
- Add branch emulation to aarch64 instruction emulator (240769)
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.
Still need to add real targets under targets/ to build packages.
Differential Revision: D2796
Reviewed by: brooks imp
makes it easier to build head on stable/9, where libstdc++ is still the
default. We can revisit this when somebody will try to build base with
gcc 4.8.1 or higher, and its included libstdc++.
Reported by: rpaulo
[X86] Convert esp-relative movs of function arguments to pushes, step 2
This moves the transformation introduced in r223757 into a separate MI pass.
This allows it to cover many more cases (not only cases where there must be a
reserved call frame), and perform rudimentary call folding. It still doesn't
have a heuristic, so it is enabled only for optsize/minsize, with stack
alignment <= 8, where it ought to be a fairly clear win.
(Re-commit of r227728)
Differential Revision: http://reviews.llvm.org/D6789
This helps to get sys/boot/i386/boot2 below the required size again,
when optimizing with -Oz.
these in $LIBDIR/clang/$VERSION/include, instead of our previous custom
location in /usr/include/clang/$VERSION. This allows us to drop yet
another FreeBSD-specific patch.
to ease any rework of how clang is built to take arm64 in to account.
Submitted by: andrew
Reviewed by: andrew, emaste
Differential Revision: https://reviews.freebsd.org/D1446
the oabi is still in the tree, but it is expected this will be removed
as developers work on surrounding code.
With this commit the ARM EABI is the only supported supported ABI by
FreeBSD on ARMa 32-bit processors.
X-MFC after: never
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D876
This includes:
o All directories named *ia64*
o All files named *ia64*
o All ia64-specific code guarded by __ia64__
o All ia64-specific makefile logic
o Mention of ia64 in comments and documentation
This excludes:
o Everything under contrib/
o Everything under crypto/
o sys/xen/interface
o sys/sys/elf_common.h
Discussed at: BSDcan
source files could be passed to tblgen or clang-tblgen, leading to a
"Too many positional arguments specified" error message. Fix this by
replacing the too-generic ${.ALLSRC} sources with explicit paths.
Reported by: rysto32@gmail.com, rodrigc
MFC after: 3 days
and 3.4 to generate dependency files for the '.inc.h' files generated
from .td files, and .sinclude those dependency files in clang.build.mk.
This will make future incremental builds of lib/clang and usr.bin/clang
work correctly, whenever any of the .td files get modified.
Note that this will not fix any problems with incremental builds from
*before* this revision, since there will not yet be any generated
dependency files. A quick workaround is to run the following:
find /usr/obj -type f -name '*.inc.h' | xargs rm
and then a regular incremental buildworld (e.g. with -DNO_CLEAN).
MFC after: 3 days
and MK_LLDB=no, so set those explicitly (now that we can do
that). Simplify tests for these variables as well, since we know they
will always be defined regardless of the phase of the build.
all the SUBDIR entries in parallel, instead of serially. Apply this
option to a selected number of Makefiles, which can greatly speed up the
build on multi-core machines, when using make -j.
This can be extended to more Makefiles later on, whenever they are
verified to work correctly with parallel building.
I tested this on a 24-core machine, with make -j48 buildworld (N = 6):
before stddev after stddev
======= ====== ======= ======
real time 1741.1 16.5 959.8 2.7
user time 12468.7 16.4 14393.0 16.8
sys time 1825.0 54.8 2110.6 22.8
(user+sys)/real 8.2 17.1
E.g. the build was approximately 45% faster in real time. On machines
with less cores, or with lower -j settings, the speedup will not be as
impressive. But at least you can now almost max out a machine with
buildworld!
Submitted by: jilles
MFC after: 2 weeks
This targets the existing ARMv6 and ARMv7 SoCs that contain a VFP unit.
This is an optional coprocessors may not be present in all devices, however
it appears to be in all current SoCs we support.
armv6hf targets the VFP variant of the ARM EABI and our copy of gcc is too
old to support this. Because of this there are a number of WITH/WITHOUT
options that are unsupported and must be left as the default value. The
options and their required value are:
* WITH_ARM_EABI
* WITHOUT_GCC
* WITHOUT_GNUCXX
In addition, without an external toolchain, the following need to be left
as their default:
* WITH_CLANG
* WITH_CLANG_IS_CC
As there is a different method of passing float and double values to
functions the ABI is incompatible with existing armv6 binaries. To use
this a full rebuild of world is required. Because no floating point values
are passed into the kernel an armv6 kernel with VFP enabled will work with
an armv6hf userland and vice versa.
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.
The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3. The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.
Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>
MFC after: 1 month
This is in the process of being submitted to the upstream LLDB
repository. The thread list functionality is modelled in part on
GDBRemoteCommunicationClient.
LLDB bug pr16696 and code review D2267
Sponsored by: DARPA, AFRL
ludes minor changes relative to upstream, for compatibility with
FreeBSD's in-tree LLVM 3.3:
- Reverted LLDB r191806, restoring use of previous API.
- Reverted part of LLDB r189317, restoring previous enum names.
- Work around missing LLVM r192504, using previous registerEHFrames API
(limited functionality).
- Removed PlatformWindows header include and init/terminate calls.
Sponsored by: DARPA, AFRL
This connects LLDB to the build, but it is disabled by default. Add
WITH_LLDB= to src.conf to build it.
Note that LLDB requires a C++11 compiler so is disabled on platforms
using GCC.
Approved by: re (gjb)
Sponsored by: DARPA, AFRL
clang on head between r239347 and r245428.
The former revision introduced CLOCK_PROCESS_CPUTIME_ID as a clock id
for the clock_gettime() function and friends, but it was only added in
<sys/time.h>, not in <time.h>. Any program including <time.h> would
therefore not be able to use CLOCK_PROCESS_CPUTIME_ID, even though the
value of _POSIX_CPUTIME indicates its existence. The latter revision
synchronized the defines again.
Work around this problem by defining the id on the command line for the
particular .cpp file that needs it. If the id ever changes value, this
hack will need to be updated.
upcoming 3.3 release (branching and freezing expected in a few weeks).
Preliminary release notes can be found at the usual location:
<http://llvm.org/docs/ReleaseNotes.html>
An MFC is planned once the actual 3.3 release is finished.
Dont use/link ARCMT, StaticAnalyzer and Rewriter to clang when the user
specifies not to. Dont build ASTMatchers with Rewriter disabled and
StaticAnalyzer when it's disabled.
Without all those three, the clang binary shrinks (x86_64) from ~36MB
to ~32MB (unstripped).
To disable these clang components, and get a smaller clang binary built
and installed, set WITHOUT_CLANG_FULL in src.conf(5). During the
initial stages of buildworld, those extra components are already
disabled automatically, to save some build time.
MFC after: 1 week
1. Don't do upgrade_checks when using bmake. As long as we have WITH_BMAKE,
there's a bootstrap complication in ths respect. Avoid it. Make the
necessary changes to have upgrade_checks work wth bmake anyway.
2. Remove the use of -E. It's not needed in our build because we use ?= for
the respective variables, which means that we'll take the environment
value (if any) anyway.
3. Properly declare phony targets as phony as bmake is a lot smarter (and
thus agressive) about build avoidance.
4. Make sure CLEANFILES is complete and use it on .NOPATH. bmake is a lot
smarter about build avoidance and should not find files we generate in
the source tree. We should not have files in the repository we want to
generate, but this is an easier way to cross this hurdle.
5. Have behavior under bmake the same as it is under make with respect to
halting when sub-commands fail. Add "set -e" to compound commands so
that bmake is informed when sub-commands fail.
6. Make sure crunchgen uses the same make as the rest of the build. This
is important when the make utility isn't called make (but bmake for
example).
7. While here, add support for using MAKEOBJDIR to set the object tree
location. It's the second alternative bmake looks for when determining
the actual object directory (= .OBJDIR).
Submitted by: Simon Gerraty <sjg@juniper.net>
Submitted by: John Van Horne <jvanhorne@juniper.net>
to be a wrapper for the canonical system header file. Unfortunately, we do
not have one (yet) and some times it is causing weird failures when clang
is used for building ports. More complete and correct file will come from
libcxxrt in the future.
Discussed with: dim, kib, theraven
MFC after: 1 week
in the last import. They are sometimes needed when you want to use
advanced instructions.
Also, add clang's internal stdalign.h header to ObsoleteFiles.inc, since
it is redundant: we already have a stdalign.h header in /usr/include.
Pointy hat to: dim
PR: kern/167574
Submitted by: jkim
Reported by: Oliver Hartmann <ohartman@zedat.fu-berlin.de>
MFC after: 2 weeks
problem by adding -fno-strict-aliasing to CFLAGS. Since this is a global
issue that just happened to manifest on PowerPC, add this to CFLAGS
unconditionally.
MFC after: 1 week
allow the built-in operations to be redefined, at least not without
excessive force).
Instead, just disable LLVM's support for atomic operations for now.
Nothing in either clang or the tablegen tools currently depends on it.
This still allows users of head built before r198344 to upgrade to
top-of-head seamlessly.
to be gcc's default before r198344, calls to atomic builtins will not be
expanded inline. Instead, they will be generated as calls to external
functions (e.g. __sync_fetch_and_add_N), leading to linking errors later
on.
Put in a seatbelt that disables use of atomic builtins in libstdc++ and
llvm, when tuning specifically for the real i386 CPU. This does not
protect against all possible issues, but it is better than nothing.
similar to what we do for binutils. When clang's default triple starts
with 'amd64-', it does not pass a proper -target-cpu option to its
first stage.
This can lead to problems, for example when structs are memcpy'd, and
clang erroneously assumes they are 16-byte aligned. It will then use
the 'movaps' SSE instruction to implement the copy, which results in a
bus error if the struct is really 8-byte aligned.
I encountered this issue when gcc's /usr/libexec/cc1 started crashing
with SIGBUS, after rebuilding world with clang ToT, but it also affects
the version of clang that we have in the tree. We were just lucky until
now, apparently. :)
There are several bugfixes in this update, but the most important one is
to ensure __start_ and __stop_ symbols for linker sets and kernel module
metadata are always emitted in object files:
http://llvm.org/bugs/show_bug.cgi?id=9292
Before this fix, if you compiled kernel modules with clang, they would
not be properly processed by kldxref, and if they had any dependencies,
the kernel would fail to load those. Another problem occurred when
attempting to mount a tmpfs filesystem, which would result in 'operation
not supported by device'.
CLANG_PREFIX macro. This changes the default header search path when we
are building clang as part of cross-tools.
Submitted by: Dimitry Andric <dimitry at andric.com>
Reviewed by: freebsd-current
-fno-rtti. The clang libaries that really use exceptions and virtual
functions can enable LLVM_REQUIRES_EH and LLVM_REQUIRES_RTTI
respectively. This saves space on the resulting binaries and follows
what's being done upstream.
Submitted by: Dimitry Andric <dimitry at andric.com>
This commit merges the latest LLVM sources from the vendor space. It
also updates the build glue to match the new sources. Clang's version
number is changed to match LLVM's, which means /usr/include/clang/2.0
has been renamed to /usr/include/clang/2.8.
Obtained from: projects/clangbsd
I used the following command to determine which source files were
unneeded:
| for i in `find lib/clang -name '*.o'`
| do
| MATCHES="`(nm -g --defined-only $i; nm -g --defined-only \
| usr.bin/clang/clang/clang) | sed -e 's/.* //' | \
| sort | uniq -d | wc -l`"
| [ $MATCHES -eq 0 ] && echo "$i: unneeded"
| done
This should slightly improve the build times.
It seems GCC 4.2.1 on PowerPC miscompiles Clang, causing it to crash
when building even simple Hello World applications. Switch back to -O1
for this architecture.
Submitted by: nwhitehorn
Even though it's nice to use posix_spawn() instead of manually using
fork()/exec(), it's better to disable this. FreeBSD 7 doesn't support
this interface. When enabled, we can't build tblgen, which prevents us
from building FreeBSD 9 on 7.
Tested by: raj
I've looked at other places in the source tree where CLANG_VENDOR is
used and I suspect it might not be safe to use newlines here.
CLANG_VENDOR should just be defined to "FreeBSD ", just like the latest
Clang preview in OS X uses "Apple ". Properly use SVN_REVISION to define
it to the imported revision of Clang. I do want to have a date in there,
so slightly modify the code to support CLANG_VENDOR_SUFFIX.
