source compile configure --with-llvm

[wutaco]

When I run the configure --with-llvm command on Rocky 9, which version of llvm should I use?

[kongfanshen-0801]

Minimum requirements:
Theoretically, clouberry requires LLVM 4.0 or a later version.
However, it is strongly not recommended to use such an old version. The API of LLVM changes significantly between major versions, and using an old version is likely to encounter compilation errors or runtime issues.
Recommended version:
LLVM 11 is the "gold standard" version of clouberry. This is the version that the development team primarily targets for release, offering the best compatibility.
In summary, I recommend using LLVM 11.

[tuhaihe]

Hi @kongfanshen-0801 thanks for your reply.

When I built the Cloudberry using the command make -j$(nproc) -C ~/cloudberry under the Rocky 8/9 + LLVM 11, some errors returned:

In file included from ../../../../src/include/postgres.h:46,
                 from llvmjit_expr.c:16:
llvmjit_expr.c: In function ‘llvm_compile_expr’:
llvmjit_expr.c:1841:86: error: initialization of ‘struct LLVMOpaqueValue *’ from incompatible pointer type ‘ExprEvalStep *’ [-Werror=incompatible-pointer-types]
 1841 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:34: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                  ^~~~~
llvmjit_expr.c:1840:33: note: in expansion of macro ‘build_EvalXFunc’
 1840 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastInt",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1841:86: note: (near initialization for ‘(anonymous)[0]’)
 1841 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:34: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                  ^~~~~
llvmjit_expr.c:1840:33: note: in expansion of macro ‘build_EvalXFunc’
 1840 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastInt",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1841:86: error: initialization of ‘struct LLVMOpaqueValue *’ from incompatible pointer type ‘ExprEvalStep *’ [-Werror=incompatible-pointer-types]
 1841 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:52: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                                    ^~~~~
llvmjit_expr.c:1840:33: note: in expansion of macro ‘build_EvalXFunc’
 1840 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastInt",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1841:86: note: (near initialization for ‘(anonymous)[0]’)
 1841 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:52: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                                    ^~~~~
llvmjit_expr.c:1840:33: note: in expansion of macro ‘build_EvalXFunc’
 1840 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastInt",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1841:86: error: initialization of ‘struct LLVMOpaqueValue *’ from incompatible pointer type ‘ExprEvalStep *’ [-Werror=incompatible-pointer-types]
 1841 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
llvmjit_expr.c:71:62: note: in definition of macro ‘build_EvalXFunc’
   71 |                                            ((LLVMValueRef[]){__VA_ARGS__}))
      |                                                              ^~~~~~~~~~~
llvmjit_expr.c:1841:86: note: (near initialization for ‘(anonymous)[0]’)
 1841 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
llvmjit_expr.c:71:62: note: in definition of macro ‘build_EvalXFunc’
   71 |                                            ((LLVMValueRef[]){__VA_ARGS__}))
      |                                                              ^~~~~~~~~~~
llvmjit_expr.c:1841:74: error: passing argument 5 of ‘build_EvalXFuncInt’ from incompatible pointer type [-Werror=incompatible-pointer-types]
 1841 |                                                                 v_state, v_econtext, op);
      |                                                                          ^~~~~~~~~~
      |                                                                          |
      |                                                                          LLVMValueRef {aka struct LLVMOpaqueValue *}
llvmjit_expr.c:69:55: note: in definition of macro ‘build_EvalXFunc’
   69 |         build_EvalXFuncInt(b, mod, funcname, v_state, op, \
      |                                                       ^~
llvmjit_expr.c:63:90: note: expected ‘ExprEvalStep *’ but argument is of type ‘LLVMValueRef’ {aka ‘struct LLVMOpaqueValue *’}
   63 |                                                                            ExprEvalStep *op,
      |                                                                            ~~~~~~~~~~~~~~^~
llvmjit_expr.c:1842:57: error: ‘i’ undeclared (first use in this function)
 1842 |                                 LLVMBuildBr(b, opblocks[i + 1]);
      |                                                         ^
llvmjit_expr.c:1842:57: note: each undeclared identifier is reported only once for each function it appears in
In file included from ../../../../src/include/postgres.h:46,
                 from llvmjit_expr.c:16:
llvmjit_expr.c:1847:86: error: initialization of ‘struct LLVMOpaqueValue *’ from incompatible pointer type ‘ExprEvalStep *’ [-Werror=incompatible-pointer-types]
 1847 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:34: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                  ^~~~~
llvmjit_expr.c:1846:33: note: in expansion of macro ‘build_EvalXFunc’
 1846 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastStr",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1847:86: note: (near initialization for ‘(anonymous)[0]’)
 1847 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:34: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                  ^~~~~
llvmjit_expr.c:1846:33: note: in expansion of macro ‘build_EvalXFunc’
 1846 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastStr",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1847:86: error: initialization of ‘struct LLVMOpaqueValue *’ from incompatible pointer type ‘ExprEvalStep *’ [-Werror=incompatible-pointer-types]
 1847 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:52: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                                    ^~~~~
llvmjit_expr.c:1846:33: note: in expansion of macro ‘build_EvalXFunc’
 1846 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastStr",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1847:86: note: (near initialization for ‘(anonymous)[0]’)
 1847 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
../../../../src/include/c.h:780:52: note: in definition of macro ‘lengthof’
  780 | #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
      |                                                    ^~~~~
llvmjit_expr.c:1846:33: note: in expansion of macro ‘build_EvalXFunc’
 1846 |                                 build_EvalXFunc(b, mod, "ExecEvalScalarArrayOpFastStr",
      |                                 ^~~~~~~~~~~~~~~
llvmjit_expr.c:1847:86: error: initialization of ‘struct LLVMOpaqueValue *’ from incompatible pointer type ‘ExprEvalStep *’ [-Werror=incompatible-pointer-types]
 1847 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
llvmjit_expr.c:71:62: note: in definition of macro ‘build_EvalXFunc’
   71 |                                            ((LLVMValueRef[]){__VA_ARGS__}))
      |                                                              ^~~~~~~~~~~
llvmjit_expr.c:1847:86: note: (near initialization for ‘(anonymous)[0]’)
 1847 |                                                                 v_state, v_econtext, op);
      |                                                                                      ^~
llvmjit_expr.c:71:62: note: in definition of macro ‘build_EvalXFunc’
   71 |                                            ((LLVMValueRef[]){__VA_ARGS__}))
      |                                                              ^~~~~~~~~~~
llvmjit_expr.c:1847:74: error: passing argument 5 of ‘build_EvalXFuncInt’ from incompatible pointer type [-Werror=incompatible-pointer-types]
 1847 |                                                                 v_state, v_econtext, op);
      |                                                                          ^~~~~~~~~~
      |                                                                          |
      |                                                                          LLVMValueRef {aka struct LLVMOpaqueValue *}
llvmjit_expr.c:69:55: note: in definition of macro ‘build_EvalXFunc’
   69 |         build_EvalXFuncInt(b, mod, funcname, v_state, op, \
      |                                                       ^~
llvmjit_expr.c:63:90: note: expected ‘ExprEvalStep *’ but argument is of type ‘LLVMValueRef’ {aka ‘struct LLVMOpaqueValue *’}
   63 |                                                                            ExprEvalStep *op,
      |                                                                            ~~~~~~~~~~~~~~^~
cc1: all warnings being treated as errors
make[2]: *** [<builtin>: llvmjit_expr.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[2]: Leaving directory '/home/gpadmin/cloudberry/src/backend/jit/llvm'
make[1]: *** [Makefile:45: all-backend/jit/llvm-recurse] Error 2
make[1]: Leaving directory '/home/gpadmin/cloudberry/src'
make: *** [GNUmakefile:11: all-src-recurse] Error 2
make: Leaving directory '/home/gpadmin/cloudberry'

Could you help with this?

[kongfanshen-0801]

This error is caused by a compatibility issue with the LLVM API version. The error is displayed in the llvmjit_expr.c file, where the type of ExprEvalStep * is incompatible with the type of LLVMValueRef. Here is the solution:

Disable the -Werror option during compilation

make -j$(nproc) -C ~/cloudberry CFLAGS="-Wno-incompatible-pointer-types"

[edespino]

While building Cloudberry from source with the --with-llvm option, I ran into some issues on Rocky Linux 9, which ships with LLVM 19.

• Since Cloudberry is based on PostgreSQL 14.4, my understanding is that the supported LLVM versions likely extend only up to LLVM 14, consistent with the PostgreSQL REL_14_STABLE branch.
• Attempting to build with LLVM 19 fails, which makes sense given this mismatch.

Two concerns came up in this process:

1. Documentation gap: I wasn’t able to find anything in the Cloudberry docs specifying which LLVM versions are supported. This would be extremely helpful for adopters, especially as many distributions now ship newer LLVM toolchains by default.
2. Practical hurdle: Hunting for older pre-built LLVM/Clang binaries (or building them locally) isn’t a great experience.

Questions / Suggestions:

• Could the project add explicit documentation about supported LLVM versions (and perhaps recommended install methods)?
• Is there a roadmap or appetite for upgrading the JIT code base to support more current LLVM versions (LLVM 15+ through 19)?
• Finally, I don’t think disabling -Werror is a good workaround, as it risks masking critical warnings the project should catch.

I’d be happy to help test builds against newer LLVM versions if the community decides to move forward here.

Thanks,
-=e

[tuhaihe]

+1.

LLVM 19 is the default LLVM version under Rocky 8/9, which is easier for users to install from the software source via the dnf command.

During my testing with LLVM 11, I encountered a few unexpected issues in the subsequent Cloudberry build process, even after disabling -Werror. From my perspective as a regular user, it is essential to address these problems fundamentally rather than relying on temporary workarounds.

Updating the JIT code to accommodate newer LLVM versions will not only enhance compatibility but also ensure a smoother and more reliable build experience for users. I believe this is a worthwhile endeavor that will benefit the entire Cloudberry community.

[edespino]

FYI: I was able to build PostgreSQL 14.19 with LLVM/CLANG 19 on Rocky Linux 9 without any issues.