Libguestfs - Oct 2022 - Why cant't use the pie link option when compiling libgustfs

Hello?   When I compile libgustfs, it will throw
exception: undefined reference to 'caml_local_roots' when adding pie
link option. 
Why is that? The command is like this: ./configure CFLAGS="-O2 -fPIC"
LDFLAGS="-pie -Wl".


I look forward to hearing from you.
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On Fri, Oct 21, 2022 at 12:10:43AM +0800, guiHua wrote:
> Hello  
>    When I compile libgustfs, it will throw exception: undefined reference
to
> 'caml_local_roots' when adding pie link option. 
> Why is that? The command is like this:
> ./configure CFLAGS="-O2 -fPIC" LDFLAGS="-pie -Wl".
Is that LDFLAGS actually valid?  You might try putting -pie into
CFLAGS, and I don't know if -Wl has any effect at all.
> I look forward to hearing from you.
I'm not certain why, but I can tell you that caml_local_roots is a
symbol in the OCaml runtime:

$ cat > hello.ml
print_endline "hello, world"
$ ocamlopt hello.ml -o hello
$ ./hello
hello, world
$ nm hello | grep caml_local_roots
0000000000000024 a domain_field_caml_local_roots

It's actually defined here:

https://github.com/ocaml/ocaml/blob/trunk/runtime/caml/memory.h#L238

(The "domain_field_" prefix is something to do with multicore, it used
to be a global variable, but now is stored per-thread.)

What distro is this?

Rich.

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