Merge: Catch em all

Extends the `do catch` construct to catch all run time errors.
The interpreter also keep the error information if one wants it.

Pull-Request: #2411

diff --combined src/interpreter/naive_interpreter.nit
index 6e6b24b,eced30f..991d8b5
--- 1/src/interpreter/naive_interpreter.nit
--- 2/src/interpreter/naive_interpreter.nit
+++ b/src/interpreter/naive_interpreter.nit
@@@ -61,7 -61,7 +61,7 @@@ class NaiveInterprete
        var modelbuilder: ModelBuilder
  
        # The main module of the program (used to lookup method)
 -      var mainmodule: MModule
 +      var mainmodule: MModule is writable
  
        # The command line arguments of the interpreted program
        # arguments.first is the program name
@@@ -119,7 -119,10 +119,10 @@@
        var escapemark: nullable EscapeMark = null
  
        # The count of `catch` blocs that have been encountered and can catch an abort
-       var catch_count = 0
+       var catch_count = 0 is writable
+ 
+       # The last error thrown on abort/runtime error where catch_count > 0
+       var last_error: nullable FatalError = null
  
        # Is a return or a break or a continue executed?
        # Use this function to know if you must skip the evaluation of statements
@@@ -685,6 -688,15 +688,15 @@@
        var error_instance = new MutableInstance(modelbuilder.model.null_type) is lazy
  end
  
+ # A runtime error
+ class FatalError
+       # The error message
+       var message: String
+ 
+       # The problematic node, if any
+       var node: nullable ANode
+ end
+ 
  # An instance represents a value of the executed program.
  abstract class Instance
        # The dynamic type of the instance
@@@ -821,6 -833,12 +833,12 @@@ redef class ANod
        # `v` is used to know if a colored message is displayed or not
        fun fatal(v: NaiveInterpreter, message: String)
        do
+               # Abort if there is a `catch` block
+               if v.catch_count > 0 then
+                       v.last_error = new FatalError(message, self)
+                       abort
+               end
+ 
                if v.modelbuilder.toolcontext.opt_no_color.value == true then
                        sys.stderr.write("Runtime error: {message} ({location.file.filename}:{location.line_start})\n")
                else
@@@ -1689,13 -1707,8 +1707,8 @@@ en
  redef class AAbortExpr
        redef fun stmt(v)
        do
-               # Abort as asked if there is no `catch` bloc
-               if v.catch_count <= 0 then
-                       fatal(v, "Aborted")
-                       exit(1)
-               else
-                       abort
-               end
+               fatal(v, "Aborted")
+               exit(1)
        end
  end