Make separate config variable for `LLVM_LIBRARY_DIRS`

[Ericson2314]

Summary

@beanz tells me it should in fact exists, and it would be bad to put a
list of dirs in LLVM_LIBRARY_DIR. I am therefore making some changes
to help avoid this an other mistakes:

• Use a separate LLVM_CONFIG_LIBRARY_DIR (no "S") variable so we don't start putting a list in LLVM_LIBRARY_DIR by mistake.

• Define the individual dir variables first, and the define the list of dirs variables programmatically.

Also, I rearranged the definitions of the "regular" single dirs below so
LLVM_BINARY_DIR, which is the unsuffixed one, comes first before the
suffixed ones.

[beanz]

LGTM

[Ericson2314]

Fix conflicts

llvm/cmake/modules/CMakeLists.txt

 # this, but there is no easy solution.
 if(intrinsics_gen IN_LIST LLVM_COMMON_DEPENDS)
   list(REMOVE_ITEM LLVM_COMMON_DEPENDS intrinsics_gen)
 endif()
 if(omp_gen IN_LIST LLVM_COMMON_DEPENDS)
   list(REMOVE_ITEM LLVM_COMMON_DEPENDS omp_gen)
 endif()
 
+#
 # Generate LLVMConfig.cmake for the build tree.
+#
+
 set(LLVM_CONFIG_CODE "
 # LLVM_BUILD_* values available only from LLVM build tree.
 set(LLVM_BUILD_BINARY_DIR \"${LLVM_BINARY_DIR}\")
 set(LLVM_BUILD_LIBRARY_DIR \"${LLVM_LIBRARY_DIR}\")
 set(LLVM_BUILD_MAIN_INCLUDE_DIR \"${LLVM_MAIN_INCLUDE_DIR}\")
 set(LLVM_BUILD_MAIN_SRC_DIR \"${LLVM_MAIN_SRC_DIR}\")
 ")
+
+set(LLVM_CONFIG_MAIN_INCLUDE_DIR "${LLVM_MAIN_INCLUDE_DIR}")
+set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_INCLUDE_DIR}")
 set(LLVM_CONFIG_INCLUDE_DIRS
-  "${LLVM_MAIN_INCLUDE_DIR}"
-  "${LLVM_INCLUDE_DIR}"
-  )
-set(LLVM_CONFIG_INCLUDE_DIR
-  "${LLVM_INCLUDE_DIR}"
-  )
-set(LLVM_CONFIG_MAIN_INCLUDE_DIR
-  "${LLVM_MAIN_INCLUDE_DIR}"
+  "${LLVM_CONFIG_MAIN_INCLUDE_DIR}"
+  "${LLVM_CONFIG_INCLUDE_DIR}"
   )
+list(REMOVE_DUPLICATES LLVM_CONFIG_INCLUDE_DIRS)
+
+set(LLVM_CONFIG_LIBRARY_DIR "${LLVM_LIBRARY_DIR}")
 set(LLVM_CONFIG_LIBRARY_DIRS
-  "${LLVM_LIBRARY_DIR}"
+  "${LLVM_CONFIG_LIBRARY_DIR}"
+  # FIXME: Should there be other entries here?
   )
-set(LLVM_CONFIG_CMAKE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
+list(REMOVE_DUPLICATES LLVM_CONFIG_LIBRARY_DIRS)
+
 set(LLVM_CONFIG_BINARY_DIR "${LLVM_BINARY_DIR}")
+set(LLVM_CONFIG_CMAKE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
 set(LLVM_CONFIG_TOOLS_BINARY_DIR "${LLVM_TOOLS_BINARY_DIR}")
 
 # Generate a default location for lit
 if (LLVM_BUILD_UTILS)
   if (CMAKE_HOST_WIN32 AND NOT CYGWIN)
     set(LLVM_CONFIG_DEFAULT_EXTERNAL_LIT "${LLVM_CONFIG_TOOLS_BINARY_DIR}/llvm-lit.py")
   else()
     set(LLVM_CONFIG_DEFAULT_EXTERNAL_LIT "${LLVM_CONFIG_TOOLS_BINARY_DIR}/llvm-lit")

 # via CMAKE_MODULE_PATH, place API modules next to it.
 # This should be removed in the future.
 file(COPY .
   DESTINATION ${llvm_cmake_builddir}
   FILES_MATCHING PATTERN *.cmake
   PATTERN CMakeFiles EXCLUDE
   )
 
+#
 # Generate LLVMConfig.cmake for the install tree.
+#
+
 find_prefix_from_config(LLVM_CONFIG_CODE LLVM_INSTALL_PREFIX "${LLVM_INSTALL_PACKAGE_DIR}")
-set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
-set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
-set(LLVM_CONFIG_MAIN_INCLUDE_DIR "${LLVM_CONFIG_INCLUDE_DIRS}")
-set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
-set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
+
+set(LLVM_CONFIG_MAIN_INCLUDE_DIR "\${LLVM_INSTALL_PREFIX}/include")
+# This is the same as the above because the handwritten and generated headers
+# are combined in one directory at install time.
+set(LLVM_CONFIG_INCLUDE_DIR "${LLVM_CONFIG_MAIN_INCLUDE_DIR}")
+set(LLVM_CONFIG_INCLUDE_DIRS
+  "${LLVM_CONFIG_MAIN_INCLUDE_DIR}"
+  "${LLVM_CONFIG_INCLUDE_DIR}"
+  )
+list(REMOVE_DUPLICATES LLVM_CONFIG_INCLUDE_DIRS)
+
+set(LLVM_CONFIG_LIBRARY_DIR "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
+set(LLVM_CONFIG_LIBRARY_DIRS
+  "${LLVM_CONFIG_LIBRARY_DIR}"
+  # FIXME: Should there be other entries here?
+  )
+list(REMOVE_DUPLICATES LLVM_CONFIG_LIBRARY_DIRS)
+
 set(LLVM_CONFIG_BINARY_DIR "\${LLVM_INSTALL_PREFIX}")
+set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
 set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/bin")
 
 # Generate a default location for lit
 if (LLVM_INSTALL_UTILS AND LLVM_BUILD_UTILS)
   set(LLVM_CONFIG_DEFAULT_EXTERNAL_LIT "${LLVM_CONFIG_TOOLS_BINARY_DIR}/llvm-lit")
 endif()
 
 get_config_exports_includes(LLVM LLVM_CONFIG_INCLUDE_EXPORTS)

llvm/cmake/modules/LLVMConfig.cmake.in

 set(LLVM_LIBRARY_DIRS "@LLVM_CONFIG_LIBRARY_DIRS@")
 
 set(LLVM_APPEND_VC_REV "@LLVM_APPEND_VC_REV@")
 
 # These variables are duplicated for install tree but they have different
 # values for build tree.  LLVM_INCLUDE_DIRS contains both source
 # and generated include directories while the following variables have
 # them split.
-set(LLVM_INCLUDE_DIR "@LLVM_CONFIG_INCLUDE_DIR@")
+
+# These are the "main" dirs
 set(LLVM_MAIN_INCLUDE_DIR "@LLVM_CONFIG_MAIN_INCLUDE_DIR@")
-set(LLVM_LIBRARY_DIR "@LLVM_CONFIG_LIBRARY_DIRS@")
+set(LLVM_LIBRARY_DIR "@LLVM_CONFIG_LIBRARY_DIR@")
+
+# This is a secondary one for generated files
+set(LLVM_INCLUDE_DIR "@LLVM_CONFIG_INCLUDE_DIR@")
 
 set(LLVM_DEFINITIONS "@LLVM_DEFINITIONS@")
-set(LLVM_CMAKE_DIR "@LLVM_CONFIG_CMAKE_DIR@")
 set(LLVM_BINARY_DIR "@LLVM_CONFIG_BINARY_DIR@")
+set(LLVM_CMAKE_DIR "@LLVM_CONFIG_CMAKE_DIR@")
 set(LLVM_TOOLS_BINARY_DIR "@LLVM_CONFIG_TOOLS_BINARY_DIR@")
 set(LLVM_TOOLS_INSTALL_DIR "@LLVM_TOOLS_INSTALL_DIR@")
 set(LLVM_HAVE_OPT_VIEWER_MODULES @LLVM_HAVE_OPT_VIEWER_MODULES@)
 set(LLVM_CONFIGURATION_TYPES @CMAKE_CONFIGURATION_TYPES@)
 set(LLVM_ENABLE_SHARED_LIBS @BUILD_SHARED_LIBS@)
 
 set(LLVM_DEFAULT_EXTERNAL_LIT "@LLVM_CONFIG_DEFAULT_EXTERNAL_LIT@")
 set(LLVM_LIT_ARGS "@LLVM_LIT_ARGS@")