Merge pull request #1494

0020ad7d cmake: link against liblzma when found, for libunwind (moneromooo-monero)

cmake/FindLibunwind.cmake

@@ -17,6 +17,22 @@ find_path(LIBUNWIND_INCLUDE_DIR libunwind.h
 )
 
 find_library(LIBUNWIND_LIBRARIES NAMES unwind )
+if(NOT LIBUNWIND_LIBRARIES STREQUAL "LIBUNWIND_LIBRARIES-NOTFOUND")
+  if (CMAKE_COMPILER_IS_GNUCC)
+    set(LIBUNWIND_LIBRARIES "gcc_eh;${LIBUNWIND_LIBRARIES}")
+  endif()
+endif()
+
+# some versions of libunwind need liblzma, and we don't use pkg-config
+# so we just look whether liblzma is installed, and add it if it is.
+# It might not be actually needed, but doesn't hurt if it is not.
+# We don't need any headers, just the lib, as it's privately needed.
+message(STATUS "looking for liblzma")
+find_library(LIBLZMA_LIBRARIES lzma )
+if(NOT LIBLZMA_LIBRARIES STREQUAL "LIBLZMA_LIBRARIES-NOTFOUND")
+  message(STATUS "liblzma found")
+  set(LIBUNWIND_LIBRARIES "${LIBUNWIND_LIBRARIES};${LIBLZMA_LIBRARIES}")
+endif()
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Libunwind "Could not find libunwind" LIBUNWIND_INCLUDE_DIR LIBUNWIND_LIBRARIES)