[clang] Add build and install targets for clang libraries

[smeenai]

Summary

This is modeled after the existing llvm-libraries target. It's a
convenient way to include all clang libraries in a distribution.

This differs slightly from the llvm-libraries target in that it adds any
library added via add_clang_library, whereas llvm-libraries only
includes targets added via add_llvm_library that didn't use the MODULE
or BUILDTREE_ONLY arguments. add_clang_library doesn't appear to have
any equivalents of those arguments, so the conditions don't apply.

[smeenai]

Fix condition

[smeenai]

A couple of things I noticed while writing this patch:

• clang guards its install target creation with CMAKE_CONFIGURATION_TYPES, whereas LLVM uses LLVM_ENABLE_IDE. Should clang be switched over to be consistent with LLVM?
• I realize we create the install-clang-libraries-stripped target (courtesy of add_llvm_install_targets), but don't actually add any dependencies to it, so it's a no-op. llvm-libraries has this problem too. I was thinking of just making install-clang-libraries-stripped synonymous with install-clang-libraries, because a lot of these libraries will be static, and stripping them makes them unusable since it removes their symbol tables. The target name will be a lie, but the behavior seems more useful. What do you think?

[phosek]

LGTM

CMakeLists.txt

 endif()
 
 option(CLANG_INCLUDE_DOCS "Generate build targets for the Clang docs."
   ${LLVM_INCLUDE_DOCS})
 if( CLANG_INCLUDE_DOCS )
   add_subdirectory(docs)
 endif()
 
+# Custom target to install all clang libraries.
+add_custom_target(clang-libraries)
+set_target_properties(clang-libraries PROPERTIES FOLDER "Misc")
+
+if(NOT CMAKE_CONFIGURATION_TYPES)
+  add_llvm_install_targets(install-clang-libraries
+                           DEPENDS clang-libraries
+                           COMPONENT clang-libraries)
+endif()
+
+get_property(CLANG_LIBS GLOBAL PROPERTY CLANG_LIBS)
+if(CLANG_LIBS)
+  list(REMOVE_DUPLICATES CLANG_LIBS)
+  foreach(lib ${CLANG_LIBS})
+    add_dependencies(clang-libraries ${lib})
+    if(NOT CMAKE_CONFIGURATION_TYPES)
+      add_dependencies(install-clang-libraries install-${lib})
+    endif()
+  endforeach()
+endif()
+
 add_subdirectory(cmake/modules)
 
 if(CLANG_STAGE)
   message(STATUS "Setting current clang stage to: ${CLANG_STAGE}")
 endif()
 
 if (CLANG_ENABLE_BOOTSTRAP)
   include(ExternalProject)

cmake/modules/AddClang.cmake

if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY OR ${name} STREQUAL "libclang")
         ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
         RUNTIME DESTINATION bin)
 
       if (NOT CMAKE_CONFIGURATION_TYPES)
         add_llvm_install_targets(install-${name}
                                  DEPENDS ${name}
                                  COMPONENT ${name})
       endif()
+
+      set_property(GLOBAL APPEND PROPERTY CLANG_LIBS ${name})
     endif()
     set_property(GLOBAL APPEND PROPERTY CLANG_EXPORTS ${name})
   else()
     # Add empty "phony" target
     add_custom_target(${name})
   endif()
 
   set_target_properties(${name} PROPERTIES FOLDER "Clang libraries")