[llvm] [bindings/OCaml] Remove unused dep on ounit2

[mgorny]

Summary

Remove the dependency on ounit2 and the relevant lit code. It seems
that ounit2 is not used at all and all OCaml binding tests pass without
it installed.

Thanks for Josh Berdine for noticing.

[jberdine]

Looks good, thanks!

Note that it was @arbipher who first noticed that ounit is no longer used.

[arbipher]

It looks good to me.

My 5 cent (for ocaml) is to keep it and it would be easier to really add some useful ounit tests, however, this PR also has shown what needs to do to revert it back.

[mgorny]

In D119884#3326249, @jberdine wrote:

Note that it was @arbipher who first noticed that ounit is no longer used.

Ok, thanks for the correction and sorry for the mistake.

In D119884#3326515, @arbipher wrote:

My 5 cent (for ocaml) is to keep it and it would be easier to really add some useful ounit tests, however, this PR also has shown what needs to do to revert it back.

Yeah, we can easily revert this if we ever introduce ounit-based tests.

[mgorny]

Do you think this should be backported to 14.x? On one hand, it isn't exactly urgent, but it kinda sucks to require this unused dep for another release.

llvm/bindings/ocaml/README.txt

 This directory contains LLVM bindings for the OCaml programming language
 (http://ocaml.org).
 
 Prerequisites
 -------------
 
 * OCaml 4.00.0+.
 * ctypes 0.4+.
-* oUnit 2+ (only required for tests).
 * CMake (to build LLVM).
 
 Building the bindings
 ---------------------
 
 If all dependencies are present, the bindings will be built and installed
 as a part of the default CMake configuration, with no further action.
 They will only work with the specific OCaml compiler detected during the build.

llvm/cmake/config-ix.cmake

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.")
     else()
       find_ocamlfind_package(ctypes VERSION 0.4 OPTIONAL)
       if( HAVE_OCAML_CTYPES )
         message(STATUS "OCaml bindings enabled.")
-        find_ocamlfind_package(ounit2 OPTIONAL)
-        if ( HAVE_OCAML_OUNIT2 )
-          set(HAVE_OCAML_OUNIT TRUE)
-        else()
-          find_ocamlfind_package(oUnit VERSION 2 OPTIONAL)
-        endif()
         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()

llvm/test/Bindings/OCaml/lit.local.cfg

 config.suffixes = ['.ml']
 
 if not 'ocaml' in config.root.llvm_bindings:
     config.unsupported = True
-
-if not config.root.have_ocaml_ounit:
-    config.unsupported = True

llvm/test/CMakeLists.txt

 llvm_canonicalize_cmake_booleans(
   BUILD_SHARED_LIBS
   LLVM_HAVE_LIBXAR
   HAVE_OCAMLOPT
-  HAVE_OCAML_OUNIT
   LLVM_ENABLE_DIA_SDK
   LLVM_ENABLE_FFI
   LLVM_ENABLE_THREADS
   LLVM_ENABLE_CURL
   LLVM_ENABLE_ZLIB
   LLVM_ENABLE_LIBXML2
   LLVM_INCLUDE_GO_TESTS
   LLVM_LINK_LLVM_DYLIB

llvm/test/lit.site.cfg.py.in

 config.lit_tools_dir = path(r"@LLVM_LIT_TOOLS_DIR@")
 config.errc_messages = "@LLVM_LIT_ERRC_MESSAGES@"
 config.python_executable = "@Python3_EXECUTABLE@"
 config.gold_executable = "@GOLD_EXECUTABLE@"
 config.ld64_executable = "@LD64_EXECUTABLE@"
 config.osx_sysroot = path(r"@CMAKE_OSX_SYSROOT@")
 config.ocamlfind_executable = "@OCAMLFIND@"
 config.have_ocamlopt = @HAVE_OCAMLOPT@
-config.have_ocaml_ounit = @HAVE_OCAML_OUNIT@
 config.ocaml_flags = "@OCAMLFLAGS@"
 config.include_go_tests = @LLVM_INCLUDE_GO_TESTS@
 config.go_executable = "@GO_EXECUTABLE@"
 config.enable_shared = @ENABLE_SHARED@
 config.enable_assertions = @ENABLE_ASSERTIONS@
 config.targets_to_build = "@TARGETS_TO_BUILD@"
 config.native_target = "@LLVM_NATIVE_ARCH@"
 config.llvm_bindings = "@LLVM_BINDINGS@".split(' ')

llvm/utils/gn/secondary/llvm/test/BUILD.gn

extra_values = [
     # No bindings are implemented in the GN build.
     "LLVM_BINDINGS=",
     "LLVM_BYE_LINK_INTO_TOOLS=0",
 
     "GO_EXECUTABLE=",
     "LLVM_INCLUDE_GO_TESTS=0",
 
     "HAVE_OCAMLOPT=0",
-    "HAVE_OCAML_OUNIT=0",
     "OCAMLFIND=OCAMLFIND-NOTFOUND",
     "OCAMLFLAGS=",
     "LLVM_BUILD_EXAMPLES=0",
     "LLVM_HAVE_TF_AOT=0",
     "LLVM_HAVE_TF_API=0",
     "LLVM_INLINER_MODEL_AUTOGENERATED=0",
     "LLVM_RAEVICT_MODEL_AUTOGENERATED=0",
   ]