engine: Handle a case when function has no range associated.

E.g. when it was mis-detected as being a function in first place (when
accepting a symbol list files, all symbols in executable area are treated
as a function, but it still may be a constant data).

engine.py

@@ -61,7 +61,9 @@ def add_insn(self, addr, sz):
     def get_end(self):
         if self.end is not None:
             return self.end
-        return self.ranges.bounds()[1]
+        bounds = self.ranges.bounds()
+        if bounds:
+            return bounds[1]
 
     def get_end_method(self):
         if self.end is not None:
@@ -558,7 +560,8 @@ def finish_func(f):
     if f:
         log.info("Function %s (0x%x) ranges: %s" % (ADDRESS_SPACE.get_label(f.start), f.start, f.ranges.str(hex)))
         end = f.get_end()
-        ADDRESS_SPACE.set_func_end(f, end)
+        if end is not None:
+            ADDRESS_SPACE.set_func_end(f, end)
 
 def analyze(callback=lambda cnt:None):
     cnt = 0

rangeset.py

@@ -30,7 +30,8 @@ def add(self, r):
         self.r.append(r)
 
     def bounds(self):
-        return (self.r[0][0], self.r[-1][1])
+        if self.r:
+            return (self.r[0][0], self.r[-1][1])
 
     def __str__(self):
         return str(self.r)