Print stack trace on exceptions

if libunwind is found.

Useful for debugging logs.

CMakeLists.txt

@@ -243,6 +243,14 @@ endif()
 
 add_definitions("-DBLOCKCHAIN_DB=${BLOCKCHAIN_DB}")
 
+find_package(Libunwind)
+if(LIBUNWIND_FOUND)
+  message(STATUS "Using libunwind to provide stack traces")
+  add_definitions("-DHAVE_LIBUNWIND")
+else()
+  message(STATUS "Stack traces disabled")
+endif()
+
 if (UNIX AND NOT APPLE)
   # Note that at the time of this writing the -Wstrict-prototypes flag added below will make this fail
   set(THREADS_PREFER_PTHREAD_FLAG ON)
@@ -274,6 +282,10 @@ if (BERKELEY_DB)
   include_directories(${BDB_INCLUDE})
 endif()
 
+# Final setup for libunwind
+include_directories(${LIBUNWIND_INCLUDE})
+link_directories(${LIBUNWIND_LIBRARY_DIRS})
+
 if(MSVC)
   add_definitions("/bigobj /MP /W3 /GS- /D_CRT_SECURE_NO_WARNINGS /wd4996 /wd4345 /D_WIN32_WINNT=0x0600 /DWIN32_LEAN_AND_MEAN /DGTEST_HAS_TR1_TUPLE=0 /FIinline_c.h /D__SSE4_1__")
   # set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /Dinline=__inline")
@@ -394,6 +406,7 @@ else()
   set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} ${RELEASE_FLAGS}")
   if(STATIC AND NOT APPLE AND NOT FREEBSD AND NOT OPENBSD)
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static-libgcc -static-libstdc++")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--wrap=__cxa_throw")
   endif()
 endif()
 
@@ -431,6 +444,11 @@ elseif(NOT MSVC)
   set(EXTRA_LIBRARIES ${RT})
 endif()
 
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  find_library(DL dl)
+  set(EXTRA_LIBRARIES ${DL})
+endif()
+
 include(version.cmake)
 
 add_subdirectory(contrib)