cmake: Install the OCaml libraries into a more correct path

Add a OCAML_INSTALL_PATH variable that can be used to control
the install path for OCaml libraries. The new variable defaults to
${OCAML_STDLIB_PATH}, i.e. the OCaml library path obtained from
the OCaml compiler. Install libraries into "llvm" subdirectory.

This fixes two issues:

1. OCaml library directories differ between systems, and 'lib/ocaml' is
incorrect e.g. on amd64 Gentoo where OCaml is installed
in 'lib64/ocaml'. Therefore, obtain the library path from the OCaml
compiler using 'ocamlc -where' (which is already used to set
OCAML_STDLIB_PATH), which is the method used commonly in OCaml packages.

2. The top-level directory is reserved for the standard library, and has
precedence over local directory in search path. As a result, OCaml
preferred the files installed along with previous LLVM version over the
source tree when building a new version, resulting in two versions being
mixed during the build. The new layout is used commonly by other OCaml
packages, and findlib is able to find the LLVM libraries successfully.

Bug: https://bugs.gentoo.org/559134
Bug: https://bugs.gentoo.org/559624

Differential Revision: https://reviews.llvm.org/D24354

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282895 91177308-0d34-0410-b5e6-96231b3b80d8

bindings/ocaml/backends/CMakeLists.txt

@@ -23,5 +23,5 @@ foreach(TARGET ${LLVM_TARGETS_TO_BUILD})
     "${LLVM_LIBRARY_DIR}/ocaml/META.llvm_${TARGET}")
 
   install(FILES "${LLVM_LIBRARY_DIR}/ocaml/META.llvm_${TARGET}"
-          DESTINATION lib/ocaml)
+          DESTINATION "${LLVM_OCAML_INSTALL_PATH}")
 endforeach()

bindings/ocaml/backends/META.llvm_backend.in

@@ -4,4 +4,4 @@ description = "@TARGET@ Backend for LLVM"
 requires = "llvm"
 archive(byte) = "llvm_@TARGET@.cma"
 archive(native) = "llvm_@TARGET@.cmxa"
-directory = "."
+directory = "llvm"

bindings/ocaml/llvm/CMakeLists.txt

@@ -8,4 +8,4 @@ configure_file(
   "${LLVM_LIBRARY_DIR}/ocaml/META.llvm")
 
 install(FILES "${LLVM_LIBRARY_DIR}/ocaml/META.llvm"
-        DESTINATION lib/ocaml)
+        DESTINATION "${LLVM_OCAML_INSTALL_PATH}")

bindings/ocaml/llvm/META.llvm.in

@@ -3,7 +3,7 @@ version = "@PACKAGE_VERSION@"
 description = "LLVM OCaml bindings"
 archive(byte) = "llvm.cma"
 archive(native) = "llvm.cmxa"
-directory = "."
+directory = "llvm"
 
 package "analysis" (
     requires = "llvm"

cmake/config-ix.cmake

@@ -554,6 +554,9 @@ else()
         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()

cmake/modules/AddOCaml.cmake

@@ -53,8 +53,8 @@ function(add_ocaml_library name)
   endif()
 
   set(ocaml_flags "-lstdc++" "-ldopt" "-L${LLVM_LIBRARY_DIR}"
-                  "-ccopt" "-L\\$CAMLORIGIN/.."
-                  "-ccopt" "-Wl,-rpath,\\$CAMLORIGIN/.."
+                  "-ccopt" "-L\\$CAMLORIGIN/../.."
+                  "-ccopt" "-Wl,-rpath,\\$CAMLORIGIN/../.."
                   ${ocaml_pkgs})
 
   foreach( ocaml_dep ${ARG_OCAMLDEP} )
@@ -135,9 +135,9 @@ function(add_ocaml_library name)
   endforeach()
 
   if( APPLE )
-    set(ocaml_rpath "@executable_path/../../lib")
+    set(ocaml_rpath "@executable_path/../../../lib${LLVM_LIBDIR_SUFFIX}")
   elseif( UNIX )
-    set(ocaml_rpath "\\$ORIGIN/../../lib")
+    set(ocaml_rpath "\\$ORIGIN/../../../lib${LLVM_LIBDIR_SUFFIX}")
   endif()
   list(APPEND ocaml_flags "-ldopt" "-Wl,-rpath,${ocaml_rpath}")
 
@@ -152,7 +152,7 @@ function(add_ocaml_library name)
     OUTPUT "${bin}/${name}.odoc"
     COMMAND "${OCAMLFIND}" "ocamldoc"
             "-I" "${bin}"
-            "-I" "${LLVM_LIBRARY_DIR}/ocaml/"
+            "-I" "${LLVM_LIBRARY_DIR}/ocaml/llvm/"
             "-dump" "${bin}/${name}.odoc"
             ${ocaml_pkgs} ${ocaml_inputs}
     DEPENDS ${ocaml_inputs} ${ocaml_outputs}
@@ -193,22 +193,25 @@ function(add_ocaml_library name)
   endforeach()
 
   install(FILES ${install_files}
-          DESTINATION lib/ocaml)
+          DESTINATION "${LLVM_OCAML_INSTALL_PATH}/llvm")
   install(FILES ${install_shlibs}
           PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE
                       GROUP_READ GROUP_EXECUTE
                       WORLD_READ WORLD_EXECUTE
-          DESTINATION lib/ocaml)
+          DESTINATION "${LLVM_OCAML_INSTALL_PATH}/llvm")
 
   foreach( install_file ${install_files} ${install_shlibs} )
     get_filename_component(filename "${install_file}" NAME)
     add_custom_command(TARGET "ocaml_${name}" POST_BUILD
       COMMAND "${CMAKE_COMMAND}" "-E" "copy" "${install_file}"
-                                             "${LLVM_LIBRARY_DIR}/ocaml/"
+                                             "${LLVM_LIBRARY_DIR}/ocaml/llvm/"
       COMMENT "Copying OCaml library component ${filename} to intermediate area"
       VERBATIM)
+    add_dependencies("ocaml_${name}" ocaml_make_directory)
   endforeach()
 endfunction()
 
+add_custom_target(ocaml_make_directory
+  COMMAND "${CMAKE_COMMAND}" "-E" "make_directory" "${LLVM_LIBRARY_DIR}/ocaml/llvm")
 add_custom_target("ocaml_all")
-set_target_properties(ocaml_all PROPERTIES FOLDER "Misc")
+set_target_properties(ocaml_all PROPERTIES FOLDER "Misc")

test/lit.cfg

@@ -102,13 +102,13 @@ if llvm_lib_dir is None:
         llvm_lib_dir = os.path.join(llvm_obj_root, 'lib')
 
 if llvm_lib_dir is not None:
-    llvm_ocaml_lib = os.path.join(llvm_lib_dir, 'ocaml')
+    top_ocaml_lib = os.path.join(llvm_lib_dir, 'ocaml')
+    llvm_ocaml_lib = os.path.join(top_ocaml_lib, 'llvm')
     if llvm_ocaml_lib is not None:
+        ocamlpath = os.path.pathsep.join((llvm_ocaml_lib, top_ocaml_lib))
         if 'OCAMLPATH' in os.environ:
-            ocamlpath = os.path.pathsep.join((llvm_ocaml_lib, os.environ['OCAMLPATH']))
-            config.environment['OCAMLPATH'] = ocamlpath
-        else:
-            config.environment['OCAMLPATH'] = llvm_ocaml_lib
+            ocamlpath = os.path.pathsep.join((ocamlpath, os.environ['OCAMLPATH']))
+        config.environment['OCAMLPATH'] = ocamlpath
 
         if 'CAML_LD_LIBRARY_PATH' in os.environ:
             caml_ld_library_path = os.path.pathsep.join((llvm_ocaml_lib,