From 24a6fb0a17caf9b5137027e41751fc7e82c7e3f0 Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Sat, 7 Mar 2015 10:30:34 +0000
Subject: [PATCH] Teach the LLVM CMake build how to explicitly use libc++abi
 when using libc++. This lets me almost self-host on Linux with libc++ and
 libc++abi very simply.

Currently, MCJIT and OrcJIT are failing due to uncaught exceptions, and
the Go binding tests are failing to build due to not linking in the
correct C++ standard library.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231560 91177308-0d34-0410-b5e6-96231b3b80d8
---
 CMakeLists.txt                       |  1 +
 cmake/modules/HandleLLVMStdlib.cmake | 26 ++++++++++++++++----------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5dda69629e1..fe177259f0a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -252,6 +252,7 @@ endif()
 option(LLVM_ENABLE_MODULES "Compile with C++ modules enabled." OFF)
 option(LLVM_ENABLE_CXX1Y "Compile with C++1y enabled." OFF)
 option(LLVM_ENABLE_LIBCXX "Use libc++ if available." OFF)
+option(LLVM_ENABLE_LIBCXXABI "Use libc++abi when using libc++." OFF)
 option(LLVM_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
 option(LLVM_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
 
diff --git a/cmake/modules/HandleLLVMStdlib.cmake b/cmake/modules/HandleLLVMStdlib.cmake
index 47bb6cddc8e..66ad078fb66 100644
--- a/cmake/modules/HandleLLVMStdlib.cmake
+++ b/cmake/modules/HandleLLVMStdlib.cmake
@@ -12,22 +12,28 @@ if(NOT DEFINED LLVM_STDLIB_HANDLED)
     set(LLVM_COMPILER_IS_GCC_COMPATIBLE ON)
   endif()
 
-  function(append_if condition value)
-    if(${condition})
-      foreach(variable ${ARGN})
-        set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
-      endforeach(variable)
-    endif()
+  function(append value)
+    foreach(variable ${ARGN})
+      set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
+    endforeach(variable)
   endfunction()
 
   include(CheckCXXCompilerFlag)
   if(LLVM_ENABLE_LIBCXX)
     if(LLVM_COMPILER_IS_GCC_COMPATIBLE)
       check_cxx_compiler_flag("-stdlib=libc++" CXX_SUPPORTS_STDLIB)
-      append_if(CXX_SUPPORTS_STDLIB "-stdlib=libc++" CMAKE_CXX_FLAGS)
-      append_if(CXX_SUPPORTS_STDLIB "-stdlib=libc++" CMAKE_EXE_LINKER_FLAGS)
-      append_if(CXX_SUPPORTS_STDLIB "-stdlib=libc++" CMAKE_SHARED_LINKER_FLAGS)
-      append_if(CXX_SUPPORTS_STDLIB "-stdlib=libc++" CMAKE_MODULE_LINKER_FLAGS)
+      if(CXX_SUPPORTS_STDLIB)
+        append("-stdlib=libc++"
+          CMAKE_CXX_FLAGS CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS
+          CMAKE_MODULE_LINKER_FLAGS)
+        if(LLVM_ENABLE_LIBCXXABI)
+          append("-lc++abi"
+            CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS
+            CMAKE_MODULE_LINKER_FLAGS)
+        endif()
+      else()
+        message(WARNING "Can't specify libc++ with '-stdlib='")
+      endif()
     else()
       message(WARNING "Not sure how to specify libc++ for this compiler")
     endif()