sdl: integrate backward-cpp (https://github.com/bombela/backward-cpp) to generate more helpful debugging output

SConstruct

@@ -27,7 +27,7 @@ opts.AddVariables(
   BoolVariable('SYSTEM_LUA','Use system lua instead of static lua provided with fceux', 1),
   BoolVariable('SYSTEM_MINIZIP', 'Use system minizip instead of static minizip provided with fceux', 0),
   BoolVariable('LSB_FIRST', 'Least signficant byte first (non-PPC)', 1),
-  BoolVariable('CLANG', 'Compile with llvm-clang instead of gcc', 1),
+  BoolVariable('CLANG', 'Compile with llvm-clang instead of gcc', 0),
   BoolVariable('SDL2', 'Compile using SDL2 instead of SDL 1.2 (experimental/non-functional)', 0)
 )
 AddOption('--prefix', dest='prefix', type='string', nargs=1, action='store', metavar='DIR', help='installation prefix')
@@ -83,6 +83,13 @@ if env['PLATFORM'] == 'win32':
   env.Append(LIBS = ["rpcrt4", "comctl32", "vfw32", "winmm", "ws2_32", "comdlg32", "ole32", "gdi32", "htmlhelp"])
 else:
   conf = Configure(env)
+  # If libdw is available, compile in backward-cpp support
+  if conf.CheckLib('dw'):
+    conf.env.Append(CCFLAGS = "-DBACKWARD_HAS_DW=1")
+    conf.env.Append(LINKFLAGS = "-ldw")
+    # workaround for upstream backward-cpp issue (https://github.com/bombela/backward-cpp/issues/2)
+    if env['CLANG']:
+      conf.env.Append(CCFLAGS = "-DBACKWARD_HAS_BACKTRACE=1")
   if conf.CheckFunc('asprintf'):
     conf.env.Append(CCFLAGS = "-DHAVE_ASPRINTF")
   if env['SYSTEM_MINIZIP']:

src/utils/SConscript

@@ -2,6 +2,7 @@ import glob
 #source_list = glob.glob('*.cpp')
 source_list = Split(
 """
+backward.cpp
 ConvertUTF.c
 xstring.cpp
 crc32.cpp     
@@ -14,6 +15,7 @@ memory.cpp
 
 Import('env')
 
+
 if env['SYSTEM_MINIZIP'] == 0:
   source_list.append('unzip.cpp')
   source_list.append('ioapi.cpp')

src/utils/backward.cpp

@@ -0,0 +1,33 @@
+// Pick your poison.
+//
+// On GNU/Linux, you have few choices to get the most out of your stack trace.
+//
+// By default you get:
+//	- object filename
+//	- function name
+//
+// In order to add:
+//	- source filename
+//	- line and column numbers
+//	- source code snippet (assuming the file is accessible)
+
+// Install one of the following library then uncomment one of the macro (or
+// better, add the detection of the lib and the macro definition in your build
+// system)
+
+// - apt-get install libdw-dev ...
+// - g++/clang++ -ldw ...
+// #define BACKWARD_HAS_DW 1
+
+// - apt-get install binutils-dev ...
+// - g++/clang++ -lbfd ...
+// #define BACKWARD_HAS_BFD 1
+#if BACKWARD_HAS_DW==1
+#include "backward.hpp"
+
+namespace backward {
+
+backward::SignalHandling sh;
+
+} // namespace backward
+#endif