Re: broken JIT support on Fedora 40 - Mailing list pgsql-hackers

On Sun, Mar 31, 2024 at 12:49 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> https://github.com/llvm/llvm-project/pull/87093

Oh, with those clues, I think I might see...  It is a bit strange that
we copy attributes from AttributeTemplate(), a function that returns
Datum, to our void deform function.  It works (I mean doesn't crash)
if you just comment this line out:

    llvm_copy_attributes(AttributeTemplate, v_deform_fn);

... but I guess that disables inlining of the deform function?  So
perhaps we just need to teach that thing not to try to copy the return
value's attributes, which also seems to work here:

diff --git a/src/backend/jit/llvm/llvmjit.c b/src/backend/jit/llvm/llvmjit.c
index ec0fdd49324..92b4993a98a 100644
--- a/src/backend/jit/llvm/llvmjit.c
+++ b/src/backend/jit/llvm/llvmjit.c
@@ -552,8 +552,11 @@ llvm_copy_attributes(LLVMValueRef v_from,
LLVMValueRef v_to)
        /* copy function attributes */
        llvm_copy_attributes_at_index(v_from, v_to, LLVMAttributeFunctionIndex);

-       /* and the return value attributes */
-       llvm_copy_attributes_at_index(v_from, v_to, LLVMAttributeReturnIndex);
+       if (LLVMGetTypeKind(LLVMGetFunctionReturnType(v_to)) !=
LLVMVoidTypeKind)
+       {
+               /* and the return value attributes */
+               llvm_copy_attributes_at_index(v_from, v_to,
LLVMAttributeReturnIndex);
+       }