Re: JIT compiling with LLVM v9.0

On 01/29/2018 11:17 PM, Andres Freund wrote:
> On 2018-01-29 23:01:14 +0100, Tomas Vondra wrote:
>> On 01/29/2018 10:57 PM, Andres Freund wrote:
>>> Hi,
>>>
>>> On 2018-01-29 22:51:38 +0100, Tomas Vondra wrote:
>>>> Hi, I wanted to look at this, but my attempts to build the jit branch
>>>> fail with some compile-time warnings (uninitialized variables) and
>>>> errors (unknown types, incorrect number of arguments). See the file
>>>> attached.
>>>
>>> Which git hash are you building?  What llvm version is this building
>>> against?  If you didn't specify LLVM_CONFIG=... what does llvm-config
>>> --version return?
>>>
>>
>> I'm building against fdc6c7a6dddbd6df63717f2375637660bcd00fc6 (current
>> HEAD in the jit branch, AFAICS).
> 
> The warnings come from an incomplete patch I probably shouldn't have
> pushed (Heavily-WIP: JIT hashing.). They should largely be irrelevant
> (although will cause a handful of "ERROR: hm" regression failures),
> but I'll definitely pop that commit on the next rebase.  If you want you
> can just reset --hard to its parent.
> 

OK

> 
> That errors are weird however:
> 
>> ...                                          ^
> 
>> I'm building like this:
>>
>> $ ./configure --enable-debug CFLAGS="-fno-omit-frame-pointer -O2" \
>>               --with-llvm --prefix=/home/postgres/pg-llvm
>>
>> $ make -s -j4 install
>>
>> and llvm-config --version says this:
>>
>> $ llvm-config --version
>> 5.0.0svn
> 
> Is thta llvm-config the one in /usr/local/include/ referenced by the
> error message above?

I don't see it referenced anywhere, but it comes from here:

$ which llvm-config
/usr/local/bin/llvm-config

> Or is it possible that llvm-config is from a different version than
> the one the compiler picks the headers up from?
> 

I don't think so. I don't have any other llvm versions installed, AFAICS.

> could you go to src/backend/lib, rm llvmjit.o, and show the full output
> of make llvmjit.o?
> 

Attached.

> I wonder whether the issue is that my configure patch does
>         -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
> rather than
>         -I*|-D*) CPPFLAGS="$pgac_option $CPPFLAGS";;
> and that it thus picks up the wrong header first?
> 

I've tried this configure tweak:

   if test -n "$LLVM_CONFIG"; then
     for pgac_option in `$LLVM_CONFIG --cflags`; do
       case $pgac_option in
-        -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+        -I*|-D*) CPPFLAGS="$pgac_option $CPPFLAGS";;
       esac
     done

and that indeed changes the failure to this:

Writing postgres.bki
Writing schemapg.h
Writing postgres.description
Writing postgres.shdescription
llvmjit_error.cpp: In function ‘void llvm_enter_fatal_on_oom()’:
llvmjit_error.cpp:61:3: error: ‘install_bad_alloc_error_handler’ is not
a member of ‘llvm’
   llvm::install_bad_alloc_error_handler(fatal_llvm_new_handler);
   ^~~~
llvmjit_error.cpp: In function ‘void llvm_leave_fatal_on_oom()’:
llvmjit_error.cpp:77:3: error: ‘remove_bad_alloc_error_handler’ is not a
member of ‘llvm’
   llvm::remove_bad_alloc_error_handler();
   ^~~~
llvmjit_error.cpp: In function ‘void llvm_reset_fatal_on_oom()’:
llvmjit_error.cpp:92:3: error: ‘remove_bad_alloc_error_handler’ is not a
member of ‘llvm’
   llvm::remove_bad_alloc_error_handler();
   ^~~~
make[3]: *** [<builtin>: llvmjit_error.o] Error 1
make[2]: *** [common.mk:45: lib-recursive] Error 2
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [Makefile:38: all-backend-recurse] Error 2
make: *** [GNUmakefile:11: all-src-recurse] Error 2


I'm not sure what that means, though ... maybe I really have system
broken in some strange way.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services