don't use singleton for symbol_table This is the first of a series of changes to make the symbol table a part of the interpreter instead of a global object. These changes also aim to simplify the implementation of symbol table so that it is easier to understand and modify. * Functions now own their scope (workspace) data. * The list of subfunctions is contained in the scope rather than a global list. * symtab.h, symtab.cc (class symbol_table): Don't use singleton pattern. * interpreter.h, interpreter.cc (interpreter::m_symbol_table): New data member. (interpreter::~interpreter): Don't set instance to 0. * interpreter-private.h, interpreter-private.cc (__get_symbol_table__): New function. Change all uses of call_stack to access call_stack object from the interpreter.

--- a/libinterp/parse-tree/pt-idx.cc	Fri Jun 09 11:36:34 2017 -0400
+++ b/libinterp/parse-tree/pt-idx.cc	Fri Jun 09 02:21:28 2017 -0400
@@ -26,6 +26,7 @@
 
 #include "Cell.h"
 #include "error.h"
+#include "interpreter-private.h"
 #include "oct-map.h"
 #include "ovl.h"
 #include "oct-lvalue.h"
@@ -215,7 +216,9 @@
 
       e.set_var (var);
 
-      octave_value fcn = symbol_table::find_function (var);
+      symbol_table& symtab = octave::__get_symbol_table__ ("final_index_error");
+
+      octave_value fcn = symtab.find_function (var);
 
       if (fcn.is_function ())
         {