Re: JIT compiling with LLVM v9.0

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.

That errors are weird however:

> llvmjit.c: In function ‘llvm_get_function’:
> llvmjit.c:239:45: warning: passing argument 2 of ‘LLVMOrcGetSymbolAddress’ from incompatible pointer type [-Wincompatible-pointer-types]
> if (LLVMOrcGetSymbolAddress(llvm_opt0_orc, &addr, mangled))
> ^
> In file included from llvmjit.c:45:0:
> /usr/local/include/llvm-c/OrcBindings.h:129:22: note: expected ‘const char *’ but argument is of type ‘LLVMOrcTargetAddress * {aka long unsigned int *}’
> LLVMOrcTargetAddress LLVMOrcGetSymbolAddress(LLVMOrcJITStackRef JITStack,
> ^~~~~~~~~~~~~~~~~~~~~~~
> llvmjit.c:239:6: error: too many arguments to function ‘LLVMOrcGetSymbolAddress’
> if (LLVMOrcGetSymbolAddress(llvm_opt0_orc, &addr, mangled))
> ^~~~~~~~~~~~~~~~~~~~~~~
> In file included from llvmjit.c:45:0:
> /usr/local/include/llvm-c/OrcBindings.h:129:22: note: declared here
> LLVMOrcTargetAddress LLVMOrcGetSymbolAddress(LLVMOrcJITStackRef JITStack,
> ^~~~~~~~~~~~~~~~~~~~~~~
> llvmjit.c:243:45: warning: passing argument 2 of ‘LLVMOrcGetSymbolAddress’ from incompatible pointer type [-Wincompatible-pointer-types]
> if (LLVMOrcGetSymbolAddress(llvm_opt3_orc, &addr, mangled))
> ^

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

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

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?

Greetings,

Andres Freund