commit d2f56dec302114d2bff748d59335bc1263f45566
author Adhemerval Zanella <adhemerval.zanella@linaro.org> Wed Sep 25 21:46:24 2019 +0000
committer Adhemerval Zanella <adhemerval.zanella@linaro.org> Wed Sep 25 21:46:24 2019 +0000
tree abfc1e32ba84f44b9503a2658d3337340d04662d
parent 61bb6c013f9957e21e755ec9dc7ad90deb869a59

[libcxxabi] Fix arm build failer with libgcc

Both arm32 armv7/armv8 bots which do not use compiler-rt are failing
to a linking issue:

[100%] Built target cxxabi_static
CMakeFiles/cxxabi_shared.dir/cxa_demangle.cpp.o: In function `(anonymous namespace)::itanium_demangle::OutputStream::writeUnsigned(unsigned long long, bool)':
/home/buildslave/buildslave/libcxx-libcxxabi-libunwind-armv7-linux-noexceptions/llvm/projects/libcxxabi/src/demangle/Utility.h:55: undefined reference to `__aeabi_uldivmod'
/home/buildslave/buildslave/libcxx-libcxxabi-libunwind-armv7-linux-noexceptions/llvm/projects/libcxxabi/src/demangle/Utility.h:56: undefined reference to `__aeabi_uldivmod'
clang-6.0: error: linker command failed with exit code 1 (use -v to see invocation)

It seems after r371273 OutputStream is used more extensively and
is pulling OutputStream::writeUnsigned (which thus requires unsigned
integer module).

The straightfoward fix is to explicit link against libgcc if
compiler-rt is not used.

git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@372921 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/config-ix.cmake

diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 9195dfc..94f89be 100644
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -7,6 +7,7 @@
 check_library_exists(c fopen "" LIBCXXABI_HAS_C_LIB)
 if (NOT LIBCXXABI_USE_COMPILER_RT)
   check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXXABI_HAS_GCC_S_LIB)
+  check_library_exists(gcc __aeabi_uldivmod "" LIBCXXABI_HAS_GCC_LIB)
 endif ()
 
 # libc++abi is built with -nodefaultlibs, so we want all our checks to also
@@ -26,8 +27,13 @@
     list(APPEND CMAKE_REQUIRED_FLAGS -rtlib=compiler-rt)
     find_compiler_rt_library(builtins LIBCXXABI_BUILTINS_LIBRARY)
     list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBCXXABI_BUILTINS_LIBRARY}")
-  elseif (LIBCXXABI_HAS_GCC_S_LIB)
-    list(APPEND CMAKE_REQUIRED_LIBRARIES gcc_s)
+  else ()
+    if (LIBCXXABI_HAS_GCC_S_LIB)
+      list(APPEND CMAKE_REQUIRED_LIBRARIES gcc_s)
+    endif ()
+    if (LIBCXXABI_HAS_GCC_LIB)
+      list(APPEND CMAKE_REQUIRED_LIBRARIES gcc)
+    endif ()
   endif ()
   if (MINGW)
     # Mingw64 requires quite a few "C" runtime libraries in order for basic

src/CMakeLists.txt

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 6b8f76b..6cfcb9c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -91,6 +91,10 @@
   list(APPEND LIBCXXABI_LIBRARIES ${MINGW_LIBRARIES})
 endif()
 
+if (NOT LIBCXXABI_USE_COMPILER_RT)
+  add_library_flags_if(LIBCXXABI_HAS_GCC_LIB gcc)
+endif ()
+
 # Setup flags.
 add_link_flags_if_supported(-nodefaultlibs)