Don't look for OCaml if LLVM_ENABLE_OCAMLDOC=OFF

[whitequark]

Why?

[amadio]

Because the "Could NOT find ..." messages interfere with automated checks of issues: https://bugs.gentoo.org/641536.
Maybe LLVM should consider at least using find_package($PKG QUIET) to avoid the unnecessary verbosity, although in the case of OCaml it didn't have any effect, due to the custom FindOCaml.cmake which does not implement the QUIET option.

[whitequark]

Whether the bindings are enabled have nothing to do with whether ocamldoc is. Fix your automated checker.

[amadio]

I patched ROOT in Gentoo to avoid the error messages, but how could OCaml bindings be turned off in LLVM if OCaml is installed at configure time? (and avoiding the package lookup if it's not needed?)
Another comment is that include(FindOCaml) and find_package(OCaml) serve more or less the same purpose, so the error message appears twice. One of the lines could be removed.

[whitequark]

how could OCaml bindings be turned off in LLVM if OCaml is installed at configure time? (and avoiding the package lookup if it's not needed?)

That's not supported for any of the bindings right now.

Another comment is that include(FindOCaml) and find_package(OCaml) serve more or less the same purpose, so the error message appears twice. One of the lines could be removed.

ACK on this.

[amadio]

This patch can be dropped as it no longer applies and there is now the option to disable OCaml bindings via LLVM_ENABLE_BINDINGS.

cmake/config-ix.cmake

 endif()
 
 # Keep the version requirements in sync with bindings/ocaml/README.txt.
-include(FindOCaml)
-include(AddOCaml)
 if(WIN32)
   message(STATUS "OCaml bindings disabled.")
 else()
-  find_package(OCaml)
-  if( NOT OCAML_FOUND )
-    message(STATUS "OCaml bindings disabled.")
-  else()
-    if( OCAML_VERSION VERSION_LESS "4.00.0" )
-      message(STATUS "OCaml bindings disabled, need OCaml >=4.00.0.")
+  if (LLVM_ENABLE_OCAMLDOC)
+    include(FindOCaml)
+    include(AddOCaml)
+    find_package(OCaml)
+    if(NOT OCAML_FOUND)
+      message(STATUS "OCaml bindings disabled.")
     else()
-      find_ocamlfind_package(ctypes VERSION 0.4 OPTIONAL)
-      if( HAVE_OCAML_CTYPES )
-        message(STATUS "OCaml bindings enabled.")
-        find_ocamlfind_package(oUnit VERSION 2 OPTIONAL)
-        set(LLVM_BINDINGS "${LLVM_BINDINGS} ocaml")
-
-        set(LLVM_OCAML_INSTALL_PATH "${OCAML_STDLIB_PATH}" CACHE STRING
-            "Install directory for LLVM OCaml packages")
+      if(OCAML_VERSION VERSION_LESS "4.00.0")
+        message(STATUS "OCaml bindings disabled, need OCaml >=4.00.0.")
       else()
-        message(STATUS "OCaml bindings disabled, need ctypes >=0.4.")
+        find_ocamlfind_package(ctypes VERSION 0.4 OPTIONAL)
+        if(HAVE_OCAML_CTYPES)
+          message(STATUS "OCaml bindings enabled.")
+          find_ocamlfind_package(oUnit VERSION 2 OPTIONAL)
+          set(LLVM_BINDINGS "${LLVM_BINDINGS} ocaml")
+
+          set(LLVM_OCAML_INSTALL_PATH "${OCAML_STDLIB_PATH}" CACHE STRING
+            "Install directory for LLVM OCaml packages")
+        else()
+          message(STATUS "OCaml bindings disabled, need ctypes >=0.4.")
+        endif()
       endif()
     endif()
   endif()