ocaml unable to find llvm module

Question

I installed llvm module with opam install llvm, and checked the libraries are correctly created. However, when I tried to use it I got Error: Unbound module Llvm error.

a@prosseek Chapter3> ocaml llvm.cma
Cannot find file llvm.cma. 

What might be wrong?

EDIT1

This is what I get from executing commands in command line.

a@prosseek Chapter4> eval `opam config env`
a@prosseek Chapter4> opam install llvm
[NOTE] Package llvm is already installed (current version is 3.2).
a@prosseek Chapter4> ocaml
        OCaml version 4.01.0

# #require "llvm";;
Unknown directive `require'.
# open Llvm;;
Error: Unbound module Llvm

From http://projects.camlcity.org/projects/dl/findlib-1.3.1/doc/guide-html/quickstart.html.

# #use "topfind";;
- : unit = ()
Findlib has been successfully loaded. Additional directives:
  #require "package";;      to load a package
  #list;;                   to list the available packages
  #camlp4o;;                to load camlp4 (standard syntax)
  #camlp4r;;                to load camlp4 (revised syntax)
  #predicates "p,q,...";;   to set these predicates
  Topfind.reset();;         to force that packages will be reloaded
  #thread;;                 to enable threads

- : unit = ()
# #require "llvm";;
/Users/smcho/.opam/system/lib/llvm/.: added to search path
# #require "llvm";;system/lib/llvm/./llvm.cma: loaded
Error: The external function `llvm_global_succ' is not available

Edit2

From llvm OCaml bindings

cd /Users/smcho/.opam/system/lib/llvm
a@prosseek llvm> ocamlfind ocamlmktop -o llvmtop -thread -linkpkg -package llvm llvm.cma -cc g++
File "llvm.cma(Llvm)", line 1:
Warning 31: files llvm.cma(Llvm) and /Users/smcho/.opam/system/lib/llvm/./llvm.cma(Llvm) both define a module named Llvm

a@prosseek llvm> llvmtop
        OCaml version 4.01.0
# #use "topfind";;
             to enable threads
- : unit = ()
# #require "llvm";;
/Users/smcho/.opam/system/lib/llvm/.: added to search path
/Users/smcho/.opam/system/lib/llvm/./llvm.cma: loaded
# open Llvm;;

However, I'm not sure how I can make it work with with ocaml, not with llvmtop. This site has the information about top loop - http://projects.camlcity.org/projects/dl/findlib-1.3.1/doc/guide-html/quickstart.html

Answer 1

I'm confused by symbols Chapter3> in your code. Where did you get it? Is it some kind of top-level? General procedure of loading modules into toplevel is:

$ eval `opam config env`
$ opam install llvm
$ ocaml
# #use "topfind";;
# #require "llvm";;
# open Llvm;;

Update Custom toplevel contains some C functions which are not loaded into default OCaml toplevel. They are linked into it. I think if you add -verbose option to ocamlfind invocation you will see some LLVM-specific linking options.