diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
index 221d9bd9452..05b51d96d76 100644
--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
@@ -533,26 +533,28 @@ endfunction()
 
 macro(add_llvm_library name)
   cmake_parse_arguments(ARG
-    "SHARED"
+    "SHARED;BUILDTREE_ONLY"
     ""
     ""
     ${ARGN})
-  if( BUILD_SHARED_LIBS )
-    llvm_add_library(${name} SHARED ${ARGN})
+  if( BUILD_SHARED_LIBS OR ARG_SHARED )
+    llvm_add_library(${name} SHARED ${ARG_UNPARSED_ARGUMENTS})
   else()
-    llvm_add_library(${name} ${ARGN})
+    llvm_add_library(${name} ${ARG_UNPARSED_ARGUMENTS})
   endif()
-  # The gtest libraries should not be installed or exported as a target
-  if ("${name}" STREQUAL gtest OR "${name}" STREQUAL gtest_main)
-    set(_is_gtest TRUE)
-  else()
-    set(_is_gtest FALSE)
+
+  # Libraries that are meant to only be exposed via the build tree only are
+  # never installed and are only exported as a target in the special build tree
+  # config file.
+  if (NOT ARG_BUILDTREE_ONLY)
     set_property( GLOBAL APPEND PROPERTY LLVM_LIBS ${name} )
   endif()
 
   if( EXCLUDE_FROM_ALL )
     set_target_properties( ${name} PROPERTIES EXCLUDE_FROM_ALL ON)
-  elseif(NOT _is_gtest)
+  elseif(ARG_BUILDTREE_ONLY)
+    set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS_BUILDTREE_ONLY ${name})
+  else()
     if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "LTO")
       set(install_dir lib${LLVM_LIBDIR_SUFFIX})
       if(ARG_SHARED OR BUILD_SHARED_LIBS)
diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
index d2510b853ad..deeaaa8be8b 100644
--- a/cmake/modules/CMakeLists.txt
+++ b/cmake/modules/CMakeLists.txt
@@ -1,9 +1,17 @@
 set(LLVM_INSTALL_PACKAGE_DIR lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm)
 set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
 
+# First for users who use an installed LLVM, create the
+# LLVMInstallationExports.cmake
+set(LLVM_EXPORTS_FILE ${llvm_cmake_builddir}/LLVMExports.cmake)
 get_property(LLVM_EXPORTS GLOBAL PROPERTY LLVM_EXPORTS)
-export(TARGETS ${LLVM_EXPORTS}
-  FILE ${llvm_cmake_builddir}/LLVMExports.cmake)
+export(TARGETS ${LLVM_EXPORTS} FILE ${LLVM_EXPORTS_FILE})
+
+# Then for users who want to link against the LLVM build tree, provide the
+# normal targets and the build tree only targets.
+set(LLVM_BUILDTREEONLY_EXPORTS_FILE ${llvm_cmake_builddir}/LLVMBuildTreeOnlyTargets.cmake)
+get_property(LLVM_EXPORTS_BUILDTREE_ONLY GLOBAL PROPERTY LLVM_EXPORTS_BUILDTREE_ONLY)
+export(TARGETS ${LLVM_EXPORTS_BUILDTREE_ONLY} FILE ${LLVM_BUILDTREEONLY_EXPORTS_FILE})
 
 get_property(LLVM_AVAILABLE_LIBS GLOBAL PROPERTY LLVM_LIBS)
 
@@ -31,11 +39,21 @@ set(LLVM_CONFIG_LIBRARY_DIRS
 set(LLVM_CONFIG_CMAKE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
 set(LLVM_CONFIG_BINARY_DIR "${LLVM_BINARY_DIR}")
 set(LLVM_CONFIG_TOOLS_BINARY_DIR "${LLVM_TOOLS_BINARY_DIR}")
-set(LLVM_CONFIG_EXPORTS_FILE "${llvm_cmake_builddir}/LLVMExports.cmake")
+# We need to use the full path to the LLVM Exports file to make sure we get the
+# one from the build tree. This is due to our cmake files being split between
+# this source dir and the binary dir in the build tree configuration and the
+# LLVM_CONFIG_CMAKE_DIR being the source directory. In contrast in the install
+# tree, both the generated LLVMExports.cmake file and the rest of the cmake
+# source files are put in the same cmake directory.
+set(LLVM_CONFIG_EXPORTS_FILE "${LLVM_EXPORTS_FILE}")
+set(LLVM_CONFIG_EXPORTS "${LLVM_EXPORTS};${LLVM_EXPORTS_BUILDTREE_ONLY}")
+set(llvm_config_include_buildtree_only_exports
+"include(\"${LLVM_BUILDTREEONLY_EXPORTS_FILE}\")")
 configure_file(
   LLVMConfig.cmake.in
   ${llvm_cmake_builddir}/LLVMConfig.cmake
   @ONLY)
+set(llvm_config_include_buildtree_only_exports)
 
 # For compatibility with projects that include(LLVMConfig)
 # via CMAKE_MODULE_PATH, place API modules next to it.
@@ -64,6 +82,7 @@ set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
 set(LLVM_CONFIG_BINARY_DIR "\${LLVM_INSTALL_PREFIX}")
 set(LLVM_CONFIG_TOOLS_BINARY_DIR "\${LLVM_INSTALL_PREFIX}/bin")
 set(LLVM_CONFIG_EXPORTS_FILE "\${LLVM_CMAKE_DIR}/LLVMExports.cmake")
+set(LLVM_CONFIG_EXPORTS "${LLVM_EXPORTS}")
 configure_file(
   LLVMConfig.cmake.in
   ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/LLVMConfig.cmake
diff --git a/cmake/modules/LLVMConfig.cmake.in b/cmake/modules/LLVMConfig.cmake.in
index 5dc9a9ef582..f7412bac108 100644
--- a/cmake/modules/LLVMConfig.cmake.in
+++ b/cmake/modules/LLVMConfig.cmake.in
@@ -68,8 +68,9 @@ set(LLVM_TOOLS_BINARY_DIR "@LLVM_CONFIG_TOOLS_BINARY_DIR@")
 set(LLVM_TOOLS_INSTALL_DIR "@LLVM_TOOLS_INSTALL_DIR@")
 
 if(NOT TARGET LLVMSupport)
-  set(LLVM_EXPORTED_TARGETS "@LLVM_EXPORTS@")
+  set(LLVM_EXPORTED_TARGETS "@LLVM_CONFIG_EXPORTS@")
   include("@LLVM_CONFIG_EXPORTS_FILE@")
+  @llvm_config_include_buildtree_only_exports@
 endif()
 
 include(${LLVM_CMAKE_DIR}/LLVM-Config.cmake)
diff --git a/utils/unittest/CMakeLists.txt b/utils/unittest/CMakeLists.txt
index c9a2cdd45c8..933399e888a 100644
--- a/utils/unittest/CMakeLists.txt
+++ b/utils/unittest/CMakeLists.txt
@@ -45,6 +45,9 @@ add_llvm_library(gtest
 
   LINK_COMPONENTS
   Support # Depends on llvm::raw_ostream
+
+  # This is a library meant only for the build tree.
+  BUILDTREE_ONLY
 )
 
 add_subdirectory(UnitTestMain)
diff --git a/utils/unittest/UnitTestMain/CMakeLists.txt b/utils/unittest/UnitTestMain/CMakeLists.txt
index 520db4e8d2b..32f0f25a60f 100644
--- a/utils/unittest/UnitTestMain/CMakeLists.txt
+++ b/utils/unittest/UnitTestMain/CMakeLists.txt
@@ -6,4 +6,7 @@ add_llvm_library(gtest_main
 
   LINK_COMPONENTS
   Support # Depends on llvm::cl
+
+  # This library is not meant to be in the install tree, only the build tree.
+  BUILDTREE_ONLY
   )