cmake,common: flag for stack trace

By default the flag is enabled whenever libunwind is found on the
system, with the exception of static build on OSX (for which we can't
install the throw hook #932 due to lack of support for --wrap in OSX
ld64 linker).

CMakeLists.txt

@@ -249,14 +249,29 @@ 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")
+# Can't install hook in static build on OSX, because OSX linker does not support --wrap
+if(LIBUNWIND_FOUND AND NOT (STATIC AND APPLE))
+  set(DEFAULT_STACK_TRACE ON)
 else()
-  message(STATUS "Stack traces disabled")
+  set(DEFAULT_STACK_TRACE OFF)
   set(LIBUNWIND_LIBRARIES "")
 endif()
 
+option(STACK_TRACE "Install a hook that dumps stack on exception" ${DEFAULT_STACK_TRACE})
+
+if(STACK_TRACE)
+  message(STATUS "Stack trace on exception enabled")
+  # Don't set CMAKE_*_FLAGS directly or add_definitions, because this flag must
+  # not be set for tests targets (TODO: per-target logic into nested CMakeLists)
+  set(STACK_TRACE_C_FLAG "-DSTACK_TRACE")
+  if (STATIC)
+    set(STACK_TRACE_LINK_FLAG "-Wl,--wrap=__cxa_throw")
+  endif()
+else()
+  message(STATUS "Stack trace on exception disabled")
+endif()
+
+
 if (UNIX AND NOT APPLE)
   # Note that at the time of this writing the -Wstrict-prototypes flag added below will make this fail
   set(THREADS_PREFER_PTHREAD_FLAG ON)
@@ -424,11 +439,6 @@ else()
   if(STATIC AND NOT APPLE AND NOT FREEBSD AND NOT OPENBSD)
     set(COMMON_EXE_LINKER_FLAGS "${COMMON_EXE_LINKER_FLAGS} -static-libgcc -static-libstdc++")
   endif()
-
-  if(STATIC AND NOT FREEBSD AND NOT OPENBSD)
-    # Install hook on throw for dumping stack on exception (implemented in libcommon)
-    set(WRAP_CXA_THROW_FLAG "-Wl,--wrap=__cxa_throw")
-  endif()
 endif()
 
 if (${BOOST_IGNORE_SYSTEM_PATHS} STREQUAL "ON")
@@ -476,12 +486,10 @@ endif()
 
 include(version.cmake)
 
-# When building the following sources...
-#   ...treat warnings as errors, install throw wrapper
-set(CMAKE_C_FLAGS "${COMMON_C_FLAGS} ${WARNINGS_AS_ERRORS_FLAG}")
-set(CMAKE_CXX_FLAGS "${COMMON_CXX_FLAGS} ${WARNINGS_AS_ERRORS_FLAG}")
-#   ...install hook on throw
-set(CMAKE_EXE_LINKER_FLAGS "${COMMON_EXE_LINKER_FLAGS} ${WRAP_CXA_THROW_FLAG}")
+# When building the following sources treat warnings as errors, install throw wrapper
+set(CMAKE_C_FLAGS "${COMMON_C_FLAGS} ${WARNINGS_AS_ERRORS_FLAG} ${STACK_TRACE_C_FLAG}")
+set(CMAKE_CXX_FLAGS "${COMMON_CXX_FLAGS} ${WARNINGS_AS_ERRORS_FLAG} ${STACK_TRACE_C_FLAG}")
+set(CMAKE_EXE_LINKER_FLAGS "${COMMON_EXE_LINKER_FLAGS} ${STACK_TRACE_LINK_FLAG}")
 
 add_subdirectory(contrib)
 add_subdirectory(src)
@@ -490,11 +498,9 @@ add_subdirectory(src)
 option(BUILD_TESTS "Build tests." OFF)
 
 if(BUILD_TESTS)
-  # When building tests...
-  #  ...do *not* treat warnings as errors
+  # When building tests, don't add some of the flags added to source build
   set(CMAKE_C_FLAGS "${COMMON_C_FLAGS}")
   set(CMAKE_CXX_FLAGS "${COMMON_CXX_FLAGS}")
-  #  ...do *not* install hook on throw
   set(CMAKE_EXE_LINKER_FLAGS "${COMMON_CXX_FLAGS}")
   add_subdirectory(tests)
 endif()

src/common/CMakeLists.txt

@@ -31,8 +31,11 @@ set(common_sources
   command_line.cpp
   dns_utils.cpp
   util.cpp
-  i18n.cpp
-  stack_trace.cpp)
+  i18n.cpp)
+
+if (STACK_TRACE)
+  list(APPEND common_sources stack_trace.cpp)
+endif()
 
 set(common_headers)
 

src/common/stack_trace.cpp

@@ -28,10 +28,8 @@
 
 #include "common/stack_trace.h"
 #include "misc_log_ex.h"
-#ifdef HAVE_LIBUNWIND
 #define UNW_LOCAL_ONLY
 #include <libunwind.h>
-#endif
 #include <cxxabi.h>
 #ifndef STATICLIB
 #include <dlfcn.h>
@@ -96,7 +94,6 @@ void set_stack_trace_log(const std::string &log)
 
 void log_stack_trace(const char *msg)
 {
-#ifdef HAVE_LIBUNWIND
   unw_context_t ctx;
   unw_cursor_t cur;
   unw_word_t ip, off;
@@ -136,7 +133,6 @@ void log_stack_trace(const char *msg)
     LOG_PRINT2(log, "  " << std::setw(4) << level << std::setbase(16) << std::setw(20) << "0x" << ip << " " << (!status && dsym ? dsym : sym) << " + " << "0x" << off, LOG_LEVEL_0);
     free(dsym);
   }
-#endif
 }
 
 }  // namespace tools

src/daemon/main.cpp

@@ -31,7 +31,6 @@
 #include "common/command_line.h"
 #include "common/scoped_message_writer.h"
 #include "common/util.h"
-#include "common/stack_trace.h"
 #include "cryptonote_core/cryptonote_core.h"
 #include "cryptonote_core/miner.h"
 #include "daemon/command_server.h"
@@ -44,6 +43,10 @@
 #include "daemon/command_line_args.h"
 #include "blockchain_db/db_types.h"
 
+#ifdef STACK_TRACE
+#include "common/stack_trace.h"
+#endif // STACK_TRACE
+
 namespace po = boost::program_options;
 namespace bf = boost::filesystem;
 
@@ -269,7 +272,9 @@ int main(int argc, char const * argv[])
         , log_file_path.filename().string().c_str()
         , log_file_path.parent_path().string().c_str()
         );
+#ifdef STACK_TRACE
       tools::set_stack_trace_log(log_file_path.filename().string());
+#endif // STACK_TRACE
     }
 
     if (command_line::has_arg(vm, daemon_args::arg_max_concurrency))