additional reworking of error handling in the parser (bug #46877) * oct-parse.in.yy (ABORT_PARSE): Delete. Replace all uses with YYABORT. Ensure that all uses of octave_base_parser::bison_error are followed by YYABORT. (octave_base_parser::make_for_command): Always delete unused parse tree elements if an error is detected. octave_base_parser::make_index_expression): Likewise. (octave_base_parser::parse_error_msg): New data member. (octave_base_parser::bison_error): Store error message for later use instead of calling parse_error. (octave_parser::run, octave_push_parser::run): Check return status of Bison-generated parser and call parse_error here with stored message. Handle exceptions generated while parsing.

--- a/libinterp/parse-tree/parse.h	Thu Jan 14 13:30:22 2016 -0800
+++ b/libinterp/parse-tree/parse.h	Thu Jan 14 16:40:12 2016 -0500
@@ -391,6 +391,10 @@
   // Generic error messages.
   void bison_error (const std::string& s, int l = -1, int c = -1);
 
+  // Contains error message if Bison-generated parser returns non-zero
+  // status.
+  std::string parse_error_msg;
+
   // Have we found an explicit end to a function?
   bool endfunction_found;