Date: Wed, 7 Aug 2019 14:37:04 -0700 From: Mark Millard <marklmi@yahoo.com> To: Brooks Davis <brooks@freebsd.org> Cc: freebsd-toolchain@freebsd.org, freebsd-ports@freebsd.org, freebsd-ppc@freebsd.org Subject: Re: devel/llvm90 requires math/z3 first; building math/z3 requires a c++ toolchain be in place Message-ID: <EEF22C3D-A4C0-4199-BABE-61982C80A283@yahoo.com> In-Reply-To: <20190807205846.GM94703@spindle.one-eyed-alien.net> References: <20190806165525.GC94703@spindle.one-eyed-alien.net> <2A88AADC-8ED0-4FFD-85A8-34C0186D5D4F@yahoo.com> <20190807020826.GH94703@spindle.one-eyed-alien.net> <602EEB6C-D0B0-4EFB-AB0E-BE98FF1C4D90@yahoo.com> <086C99B8-1289-4D81-AAF5-85FB0AE70B7C@yahoo.com> <20190807171714.GI94703@spindle.one-eyed-alien.net> <20190807180244.GJ94703@spindle.one-eyed-alien.net> <4FF9540B-E1FE-4947-8E45-8D4FB57A7E34@yahoo.com> <20190807195613.GK94703@spindle.one-eyed-alien.net> <68CDAEA5-73D8-40FB-A22F-CC3B357FA992@yahoo.com> <20190807205846.GM94703@spindle.one-eyed-alien.net>
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On 2019-Aug-7, at 13:58, Brooks Davis <brooks at freebsd.org> wrote:
> On Wed, Aug 07, 2019 at 01:42:26PM -0700, Mark Millard wrote:
>>=20
>>=20
>> On 2019-Aug-7, at 12:56, Brooks Davis <brooks at freebsd.org> wrote:
>>=20
>>> On Wed, Aug 07, 2019 at 11:55:04AM -0700, Mark Millard wrote:
>>>>=20
>>>>=20
>>>> On 2019-Aug-7, at 11:02, Brooks Davis <brooks at freebsd.org> =
wrote:
>>>>=20
>>>>> On Wed, Aug 07, 2019 at 05:17:14PM +0000, Brooks Davis wrote:
>>>>>> On Tue, Aug 06, 2019 at 09:22:52PM -0700, Mark Millard wrote:
>>>>>>> [I found something known to be missing in the
>>>>>>> in at least some versions of
>>>>>>> llvm/cmake/modules/CrossCompile.cmake that messes
>>>>>>> up the overall handling of LLVM_ENABLE_Z3_SOLVER .]
>>>>>>>=20
>>>>>>> On 2019-Aug-6, at 20:23, Mark Millard <marklmi at yahoo.com> =
wrote:
>>>>>>>=20
>>>>>>>=20
>>>>>>>=20
>>>>>>>> On 2019-Aug-6, at 19:08, Brooks Davis <brooks at freebsd.org> =
wrote:
>>>>>>>>=20
>>>>>>>>> On Tue, Aug 06, 2019 at 05:59:21PM -0700, Mark Millard wrote:
>>>>>>>>>>=20
>>>>>>>>>>=20
>>>>>>>>>> On 2019-Aug-6, at 09:55, Brooks Davis <brooks at freebsd.org> =
wrote:
>>>>>>>>>>=20
>>>>>>>>>>> I'd prefer to disable this dependency. There's a knob that =
worked in
>>>>>>>>>>> the 8.0 timeframe, but the lit build now autodetects z3 when =
it is
>>>>>>>>>>> present and I've failed to find a knob to disable it. For =
now, the easy
>>>>>>>>>>> workaround is probably to disable options LIT. We could =
make that the
>>>>>>>>>>> default on non-LLVM platforms is that makes sense.
>>>>>>>>>>>=20
>>>>>>>>>>> -- Brooks
>>>>>>>>>>=20
>>>>>>>>>> Okay.
>>>>>>>>>>=20
>>>>>>>>>> poudriere-devel automatically built math/z3 because
>>>>>>>>>> I'd indicated to build devel/llvm90 . math/z3 was not
>>>>>>>>>> previously built: I've never had other use of it. So
>>>>>>>>>> my context was not one of an implicit autodetect.
>>>>>>>>>=20
>>>>>>>>> The dependency is there because if z3 is installed then the =
package
>>>>>>>>> that is built depends on z3. Thus I had not choice but to add =
a z3
>>>>>>>>> dependency until I find a way to turn it off. You can either =
help find
>>>>>>>>> a way to disable z3 detection in the cmake infrastructure or =
turn off
>>>>>>>>> LIT. I don't have any use for reports on the effects of =
commenting out
>>>>>>>>> the DEPENDS line. I know what that does.
>>>>>>>>=20
>>>>>>>>=20
>>>>>>>> I hope this helps. (I'm not a cmake expert.)
>>>>>>>>=20
>>>>>>>> llvm-9.0.0rc1.src/lib/Support/Z3Solver.cpp does:
>>>>>>>>=20
>>>>>>>> #if LLVM_WITH_Z3
>>>>>>>>=20
>>>>>>>> #include <z3.h>
>>>>>>>>=20
>>>>>>>> namespace {
>>>>>>>> . . .
>>>>>>>> } // end anonymous namespace
>>>>>>>>=20
>>>>>>>> #endif
>>>>>>>>=20
>>>>>>>> llvm::SMTSolverRef llvm::CreateZ3Solver() {
>>>>>>>> #if LLVM_WITH_Z3
>>>>>>>> return llvm::make_unique<Z3Solver>();
>>>>>>>> #else
>>>>>>>> llvm::report_fatal_error("LLVM was not compiled with Z3 =
support, rebuild "
>>>>>>>> "with -DLLVM_ENABLE_Z3_SOLVER=3DON",
>>>>>>>> false);
>>>>>>>> return nullptr;
>>>>>>>> #endif
>>>>>>>> }
>>>>>>>>=20
>>>>>>>> (There are other places LLVM_WITH_Z3 is used but the
>>>>>>>> above is suggestive.)
>>>>>>>>=20
>>>>>>>> Working backwards finds that:
>>>>>>>>=20
>>>>>>>> =
/wrkdirs/usr/ports/devel/llvm90/work/llvm-9.0.0rc1.src/CMakeLists.txt
>>>>>>>>=20
>>>>>>>> shows LLVM_WITH_Z3 being conditionally set to 1 via . . .
>>>>>>>>=20
>>>>>>>> set(LLVM_Z3_INSTALL_DIR "" CACHE STRING "Install directory of =
the Z3 solver.")
>>>>>>>>=20
>>>>>>>> find_package(Z3 4.7.1)
>>>>>>>>=20
>>>>>>>> if (LLVM_Z3_INSTALL_DIR)
>>>>>>>> if (NOT Z3_FOUND)
>>>>>>>> message(FATAL_ERROR "Z3 >=3D 4.7.1 has not been found in =
LLVM_Z3_INSTALL_DIR: ${LLVM_Z3_INSTALL_DIR}.")
>>>>>>>> endif()
>>>>>>>> endif()
>>>>>>>>=20
>>>>>>>> set(LLVM_ENABLE_Z3_SOLVER_DEFAULT "${Z3_FOUND}")
>>>>>>>>=20
>>>>>>>> option(LLVM_ENABLE_Z3_SOLVER
>>>>>>>> "Enable Support for the Z3 constraint solver in LLVM."
>>>>>>>> ${LLVM_ENABLE_Z3_SOLVER_DEFAULT}
>>>>>>>> )
>>>>>>>>=20
>>>>>>>> if (LLVM_ENABLE_Z3_SOLVER)
>>>>>>>> if (NOT Z3_FOUND)
>>>>>>>> message(FATAL_ERROR "LLVM_ENABLE_Z3_SOLVER cannot be enabled =
when Z3 is not available.")
>>>>>>>> endif()
>>>>>>>>=20
>>>>>>>> set(LLVM_WITH_Z3 1)
>>>>>>>> endif()
>>>>>>>>=20
>>>>>>>> if( LLVM_TARGETS_TO_BUILD STREQUAL "all" )
>>>>>>>> set( LLVM_TARGETS_TO_BUILD ${LLVM_ALL_TARGETS} )
>>>>>>>> endif()
>>>>>>>>=20
>>>>>>>>=20
>>>>>>>> If I read that correctly, LLVM_ENABLE_Z3_SOLVER set directly
>>>>>>>> appears to override the default (that tracks if z3 was found).
>>>>>>>=20
>>>>>>> I saw a reference to:
>>>>>>>=20
>>>>>>> diff --git a/llvm/cmake/modules/CrossCompile.cmake =
b/llvm/cmake/modules/CrossCompile.cmake
>>>>>>> index bc3b210f018..0c30b88f80f 100644
>>>>>>> --- a/llvm/cmake/modules/CrossCompile.cmake
>>>>>>> +++ b/llvm/cmake/modules/CrossCompile.cmake
>>>>>>> @@ -53,6 +53,7 @@ function(llvm_create_cross_target_internal =
target_name toolchain buildtype)
>>>>>>> -DLLVM_DEFAULT_TARGET_TRIPLE=3D"${TARGET_TRIPLE}"
>>>>>>> -DLLVM_TARGET_ARCH=3D"${LLVM_TARGET_ARCH}"
>>>>>>> =
-DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=3D"${LLVM_TEMPORARILY_ALLOW_OLD_TOO=
LCHAIN}"
>>>>>>> + -DLLVM_ENABLE_Z3_SOLVER=3D"${LLVM_ENABLE_Z3_SOLVER}"
>>>>>>> ${build_type_flags} ${linker_flag} ${external_clang_dir}
>>>>>>> WORKING_DIRECTORY ${LLVM_${target_name}_BUILD}
>>>>>>> DEPENDS CREATE_LLVM_${target_name}
>>>>>>>=20
>>>>>>> in https://reviews.llvm.org/D54978 on Feb 12 2019, 5:41 PM
>>>>>>> and it had the comment:
>>>>>>>=20
>>>>>>> QUOTE
>>>>>>> Independent of the rest of the discussion, this patch should be =
part of the reland, to make sure that explicitly turning off Z3 works =
reliably. Thanks for coming up with that, and thanks everyone for the =
good discussion here :)
>>>>>>> END QUOTE
>>>>>>>=20
>>>>>>> This apparently fixes a sub-cmake not respecting the
>>>>>>> LLVM_ENABLE_Z3_SOLVER setting in the parent cmake.
>>>>>>> (The overall review earlier describes the sub-cmake
>>>>>>> not doing the right thing.)
>>>>>>=20
>>>>>> Thanks for digging this up. Unfortunately, this doesn't seem to =
have
>>>>>> solved the problem. With this patch applied I still get this if =
I have
>>>>>> z3 installed on the system and no LIB_DEPENDS line:
>>>>>>=20
>>>>>> Error: /usr/local/bin/FileCheck90 is linked to =
/usr/local/lib/libz3.so.0
>>>>>> from math/z3 but it is not declared as a dependency
>>>>>> Warning: you need LIB_DEPENDS+=3Dlibz3.so:math/z3
>>>>>>=20
>>>>>> I've generally observed that the portions of the system that =
cover lit
>>>>>> (which includes FileCheck) aren't very well behaved.
>>>>>=20
>>>>> I've filed https://bugs.llvm.org/show_bug.cgi?id=3D42921 upstream,
>>>>> hopefully someone who understand this part of the cmake system =
will help
>>>>> us out.
>>>>=20
>>>> You mentioned applying the patch but not also
>>>> setting:
>>>>=20
>>>> LLVM_ENABLE_Z3_SOLVER:BOOL=3DOFF
>>>>=20
>>>> with either:
>>>>=20
>>>> -D LLVM_ENABLE_Z3_SOLVER:BOOL=3DOFF
>>>>=20
>>>> on the command line or some line early in CMakeCache.txt .
>>>> (Actually, I had to look around to know to say those
>>>> specifics of what it means to have already initialized
>>>> LLVM_ENABLE_Z3_SOLVER .)
>>>>=20
>>>> =46rom what I see, taking the initial assignment via CMakeCache.txt
>>>> after it is initialized seems to be a common technique of =
controlling
>>>> the configuration.
>>>>=20
>>>> Taking from an example from web of a CMakeCache.txt . . .
>>>>=20
>>>>=20
>>>> # This is the CMakeCache file.
>>>> # For build in directory: [edited out]
>>>> # It was generated by CMake: =
/Applications/CMake.app/Contents/bin/cmake
>>>> # You can edit this file to change values found and used by cmake.
>>>> # If you do not want to change any of the values, simply exit the =
editor.
>>>> # If you do want to change a value, simply edit, save, and exit the =
editor.
>>>> # The syntax for the file is as follows:
>>>> # KEY:TYPE=3DVALUE
>>>> # KEY is the name of a variable in the cache.
>>>> # TYPE is a hint to GUIs for the type of VALUE, DO NOT EDIT TYPE!.
>>>> # VALUE is the current value for the KEY.
>>>>=20
>>>> ########################
>>>> # EXTERNAL cache entries
>>>> ########################
>>>>=20
>>>> //Build a 32 bit version of the library.
>>>> BENCHMARK_BUILD_32_BITS:BOOL=3DOFF
>>>>=20
>>>> . . . (lots omitted) . . .
>>>>=20
>>>>=20
>>>> //Fail and stop if a warning is triggered.
>>>> LLVM_ENABLE_WERROR:BOOL=3DOFF
>>>>=20
>>>> //Enable Support for the Z3 constraint solver in LLVM.
>>>> LLVM_ENABLE_Z3_SOLVER:BOOL=3DOFF
>>>>=20
>>>> //Use zlib for compression/decompression if available.
>>>> LLVM_ENABLE_ZLIB:BOOL=3DON
>>>>=20
>>>> . . . (lots more omitted) . . .
>>>>=20
>>>>=20
>>>> The example already had the "LLVM_ENABLE_Z3_SOLVER:BOOL=3DOFF"
>>>> line, I did not adjust it.
>>>=20
>>> Upstream spotted this error as well. I've hopefully committed a fix =
(of
>>> course just as I committed I discovered I'd had the patch applied =
and it
>>> shouldn't be needed so I'm now rebuilding again and will add the =
patch
>>> if needed.)
>>=20
>> Just for my curiosity: which way are you
>> initializing LLVM_ENABLE_Z3_SOLVER to OFF ?:
>>=20
>> A) Having -D LLVM_ENABLE_Z3_SOLVER:BOOL=3DOFF on the cmake command =
line?
>> B) Having LLVM_ENABLE_Z3_SOLVER:BOOL=3DOFF in the CMakeCache.txt =
file?
>> C) Something else (that I missed as a technique)?
>=20
> (A) via:
>=20
> CMAKE_ARGS+=3D -DLLVM_ENABLE_Z3_SOLVER=3DOFF
Thanks.
=46rom what I've seen the :BOOL part of the syntax should be used:
CMAKE_ARGS+=3D -DLLVM_ENABLE_Z3_SOLVER:BOOL=3DOFF
It is not a textual definition from what I gather and
the intended type should be specified as well. (But
I'm learning things as I go.)
=3D=3D=3D
Mark Millard
marklmi at yahoo.com
( dsl-only.net <http://dsl-only.net/>; went
away in early 2018-Mar)
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