dbstop: conditional breakpoint, dbstop if caught error etc. (bug #46795) * debug.cc (parse_dbfunction_params): Accept "in", "at" and "if" tokens. Only breakpoints are returned; "dbstop if error" etc. are processed in the parser. * debug.cc (dbstop_process_map_ags, Fdbstop): set breakpoints etc. based on the output of A=dbstatus. The structure of A is not Matlab compatible. * debug.cc (do_add_breakpoint_1, do_get_breakpoint_list): Store file (not subfunction) names in bp_set, to avoid crash in "dbclear all". * debug.cc (dbclear_all_signals, condition_valid, stop_on_err_warn_status): New function * debug.cc (do_add_breakpoint): take "condition" parameter. * debug.cc (do_get_breakpoint_list): Make invariant copy of bp_set (bug #44195) * debug.cc (do_add_breakpoint, do_remove_breakpoint, do_remove_all_breakpoints_in_file): More informative error messages. * debug.cc (Fdbclear): clear break on signals (error, warning etc.) * debug.cc (Fdbstatus): Return all breakpoints when debugging, so that "s = dbstatus; ...; dbstop (s)" works. (Related to bug #41338, bug #41556) * debug.cc (Fdbstatus): Return structure with conditions, and "if error" etc. * debug.h (debug_on_err, debug_on_caught, debug_on_warn): New functions * debug.h: Rename "fname_line_map" to "fname_bp_map", as it has conditions * error.cc (verror): Allow dbstop on selected errors, or errors in try/catch * error.h New globals: Vdebug_on_caught, in_try_catch. * toplev.cc: Experimental code for Matlab's "dbstop if naninf". * symtab.cc (load_class_constructor): Add class constructors to list of methods so they can be breakpointed * pt-pb.{cc,h} (take_action): Add "condition" to set_breakpoint call, track bp_cond_list. * pt-eval.cc visit_.*_command: Ask if breakpoint condition is satisfied. * pt-eval.cc (visit_try_catch_command): Count the number of levels of try/catch we are in to allow "dbstop if caught error". * pt-stmt.cc (set_breakpoint): Pass condition * pt-stmt.cc (is_breakpoint): If new argument is true, only return true if the condition is set. * pt-stmt.cc (bp_cond, preakpoints_and_conds): new function * pt-stmt.h: new declarations * pt.{cc,h} (meets_bp_condition, bp_cond): New function * octave-link.h (update_breakpoint): Accept condition

--- a/libinterp/corefcn/error.h	Sat Jan 30 08:22:36 2016 -0800
+++ b/libinterp/corefcn/error.h	Sun Jan 24 11:02:30 2016 +1100
@@ -132,6 +132,10 @@
 // traceback message (you will only see the top-level error message).
 extern OCTINTERP_API bool Vdebug_on_error;
 
+// TRUE means that Octave will try to enter the debugger when an error
+// is encountered within the 'try' section of a 'try' / 'catch' block.
+extern OCTINTERP_API bool Vdebug_on_caught;
+
 // TRUE means that Octave will try to enter the debugger when a warning
 // is encountered.
 extern OCTINTERP_API bool Vdebug_on_warning;
@@ -147,6 +151,10 @@
 // the 'unwind_protect' statement.
 extern OCTINTERP_API int buffer_error_messages;
 
+// The number of layers of try / catch blocks we're in.  Used to print
+// "caught error" instead of "error" when "dbstop if caught error" is on.
+extern OCTINTERP_API int in_try_catch;
+
 // TRUE means error messages are turned off.
 extern OCTINTERP_API bool discard_error_messages;