Fix re-building in-tree libc++ against in-tree libc++abi

[kutuzov.viktor.84]

Summary

Since the LIBCXX_CXX_ABI variable is a cached one, the code that detects in-tree libc++abi (added in rL214037) only executes during the initial build, so any successive builds actually link against the system (and not the in-tree) libc++abi.

This patch fixes that bug by introducing a dedicated non-cached variable LIB_CXX_ABI_LIBNAME.

[kutuzov.viktor.84]

Added support for custom library names specified with LIBCXX_CXX_ABI.

[kutuzov.viktor.84]

Also, it seems we should replace 'NOT DEFINED LIBCXX_CXX_ABI' with just 'NOT LIBCXX_CXX_ABI' as LIBCXX_CXX_ABI is defined during successive builds.

[kutuzov.viktor.84]

'NOT DEFINED LIBCXX_CXX_ABI' replaced with 'NOT LIBCXX_CXX_ABI'; '${LIBCXX_CXX_ABI}' quoted when set to LIBCXX_CXX_ABI_LIBNAME.

[danalbert]

Confirmed this fixes the issue. Nice catch.

[kutuzov.viktor.84]

Closed by commit rL215186 (authored by vkutuzov).

libcxx/trunk/CMakeLists.txt

 option(LIBCXX_ENABLE_ASSERTIONS "Enable assertions independent of build mode." ON)
 option(LIBCXX_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
 option(LIBCXX_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
 option(LIBCXX_ENABLE_CXX0X "Enable -std=c++0x and use of c++0x language features if the compiler supports it." ON)
 option(LIBCXX_ENABLE_SHARED "Build libc++ as a shared library." ON)
 option(LIBCXX_INSTALL_SUPPORT_HEADERS "Install libc++ support headers." ON)
 
 set(CXXABIS none libcxxabi libcxxrt libstdc++ libsupc++)
-if (NOT DEFINED LIBCXX_CXX_ABI)
-  if (NOT DEFINED LIBCXX_BUILT_STANDALONE AND IS_DIRECTORY "${CMAKE_SOURCE_DIR}/projects/libcxxabi")
-    set(LIBCXX_CXX_ABI "libcxxabi")
+if (NOT LIBCXX_CXX_ABI)
+  if (NOT DEFINED LIBCXX_BUILT_STANDALONE AND
+      IS_DIRECTORY "${CMAKE_SOURCE_DIR}/projects/libcxxabi")
+    set(LIBCXX_CXX_ABI_LIBNAME "libcxxabi")
     set(LIBCXX_LIBCXXABI_INCLUDE_PATHS "${CMAKE_SOURCE_DIR}/projects/libcxxabi/include")
     set(LIBCXX_CXX_ABI_INTREE 1)
   else ()
-    set(LIBCXX_CXX_ABI "none")
+    set(LIBCXX_CXX_ABI_LIBNAME "none")
   endif ()
-endif()
+else ()
+  set(LIBCXX_CXX_ABI_LIBNAME "${LIBCXX_CXX_ABI}")
+endif ()
 set(LIBCXX_CXX_ABI "${LIBCXX_CXX_ABI}" CACHE STRING
     "Specify C++ ABI library to use." FORCE)
 set_property(CACHE LIBCXX_CXX_ABI PROPERTY STRINGS ;${CXXABIS})
 
 #===============================================================================
 # Configure System
 #===============================================================================
 
macro(setup_abi_lib abipathvar abidefines abilibs abifiles abidirs)
   include_directories("${CMAKE_BINARY_DIR}/include")
 
   install(FILES ${abilib_headers}
     DESTINATION include/c++/v1
     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
     )
 endmacro()
 
-if ("${LIBCXX_CXX_ABI}" STREQUAL "libstdc++" OR
-    "${LIBCXX_CXX_ABI}" STREQUAL "libsupc++")
+if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++" OR
+    "${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libsupc++")
   set(_LIBSUPCXX_INCLUDE_FILES
     cxxabi.h bits/c++config.h bits/os_defines.h bits/cpu_defines.h
     bits/cxxabi_tweaks.h bits/cxxabi_forced.h
     )
-  if ("${LIBCXX_CXX_ABI}" STREQUAL "libstdc++")
+  if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++")
     set(_LIBSUPCXX_DEFINES "-DLIBSTDCXX")
     set(_LIBSUPCXX_LIBNAME stdc++)
   else()
     set(_LIBSUPCXX_DEFINES "")
     set(_LIBSUPCXX_LIBNAME supc++)
   endif()
   setup_abi_lib("LIBCXX_LIBSUPCXX_INCLUDE_PATHS"
     "-D__GLIBCXX__ ${_LIBSUPCXX_DEFINES}"
     "${_LIBSUPCXX_LIBNAME}" "${_LIBSUPCXX_INCLUDE_FILES}" "bits"
     )
-elseif ("${LIBCXX_CXX_ABI}" STREQUAL "libcxxabi")
+elseif ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libcxxabi")
   if (LIBCXX_CXX_ABI_INTREE)
     # Link against just-built "cxxabi" target.
     set(CXXABI_LIBNAME cxxabi)
   else()
     # Assume c++abi is installed in the system, rely on -lc++abi link flag.
     set(CXXABI_LIBNAME "c++abi")
   endif()
   setup_abi_lib("LIBCXX_LIBCXXABI_INCLUDE_PATHS" ""
     ${CXXABI_LIBNAME} "cxxabi.h" ""
     )
-elseif ("${LIBCXX_CXX_ABI}" STREQUAL "libcxxrt")
+elseif ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libcxxrt")
   setup_abi_lib("LIBCXX_LIBCXXRT_INCLUDE_PATHS" "-DLIBCXXRT"
     "cxxrt" "cxxabi.h;unwind.h;unwind-arm.h;unwind-itanium.h" ""
     )
-elseif (NOT "${LIBCXX_CXX_ABI}" STREQUAL "none")
+elseif (NOT "${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "none")
   message(FATAL_ERROR
     "Currently libstdc++, libsupc++, libcxxabi, libcxxrt and none are "
     "supported for c++ abi."
     )
 endif ()
 
 # Configure compiler.
 include(config-ix)

libcxx/trunk/test/lit.site.cfg.in

 @AUTO_GEN_COMMENT@
 config.cxx_under_test        = "@LIBCXX_COMPILER@"
 config.cxx_has_stdcxx0x_flag = @LIBCXX_HAS_STDCXX0X_FLAG@
 config.libcxx_src_root       = "@LIBCXX_SOURCE_DIR@"
 config.libcxx_obj_root       = "@LIBCXX_BINARY_DIR@"
 config.python_executable     = "@PYTHON_EXECUTABLE@"
 config.enable_shared         = @LIBCXX_ENABLE_SHARED@
-config.cxx_abi               = "@LIBCXX_CXX_ABI@"
+config.cxx_abi               = "@LIBCXX_CXX_ABI_LIBNAME@"
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@LIBCXX_SOURCE_DIR@/test/lit.cfg")