typing: Added typing resolution for `ACallrefExpr`
[nit.git] / src / interpreter / naive_interpreter.nit
index 1c48d8f..9b4fb1c 100644 (file)
@@ -21,7 +21,8 @@ import literal
 import semantize
 private import parser::tables
 import mixin
-import primitive_types
+private import model::serialize_model
+private import frontend::explain_assert_api
 
 redef class ToolContext
        # --discover-call-trace
@@ -60,7 +61,7 @@ class NaiveInterpreter
        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
@@ -118,7 +119,10 @@ class NaiveInterpreter
        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
@@ -316,34 +320,46 @@ class NaiveInterpreter
                end
        end
 
-       # Return a new native string initialized with `txt`
-       fun native_string_instance(txt: String): Instance
+       # Return a new C string initialized with `txt`
+       fun c_string_instance(txt: String): Instance
        do
-               var instance = native_string_instance_len(txt.byte_length+1)
+               var instance = c_string_instance_len(txt.byte_length+1)
                var val = instance.val
-               val[txt.byte_length] = 0u8
+               val[txt.byte_length] = 0
                txt.to_cstring.copy_to(val, txt.byte_length, 0, 0)
 
                return instance
        end
 
-       # Return a new native string initialized with `txt`
-       fun native_string_instance_from_ns(txt: NativeString, len: Int): Instance
+       # Return a new C string initialized with `txt`
+       fun c_string_instance_from_ns(txt: CString, len: Int): Instance
        do
-               var instance = native_string_instance_len(len)
+               var instance = c_string_instance_len(len)
                var val = instance.val
                txt.copy_to(val, len, 0, 0)
 
                return instance
        end
 
-       # Return a new native string initialized of `length`
-       fun native_string_instance_len(length: Int): PrimitiveInstance[NativeString]
+       # Return a new C string instance sharing the same data space as `txt`
+       fun c_string_instance_fast_cstr(txt: CString, from: Int): Instance
+       do
+               var ncstr = txt.fast_cstring(from)
+               var t = mainmodule.c_string_type
+
+               var instance = new PrimitiveInstance[CString](t, ncstr)
+               init_instance_primitive(instance)
+
+               return instance
+       end
+
+       # Return a new C string initialized of `length`
+       fun c_string_instance_len(length: Int): PrimitiveInstance[CString]
        do
-               var val = new NativeString(length)
+               var val = new CString(length)
 
-               var t = mainmodule.native_string_type
-               var instance = new PrimitiveInstance[NativeString](t, val)
+               var t = mainmodule.c_string_type
+               var instance = new PrimitiveInstance[CString](t, val)
                init_instance_primitive(instance)
                return instance
        end
@@ -351,8 +367,8 @@ class NaiveInterpreter
        # Return a new String instance for `txt`
        fun string_instance(txt: String): Instance
        do
-               var nat = native_string_instance(txt)
-               var res = self.send(self.force_get_primitive_method("to_s_full", nat.mtype), [nat, self.int_instance(txt.byte_length), self.int_instance(txt.length)])
+               var nat = c_string_instance(txt)
+               var res = self.send(self.force_get_primitive_method("to_s_unsafe", nat.mtype), [nat, self.int_instance(txt.byte_length), self.int_instance(txt.length), self.false_instance, self.false_instance])
                assert res != null
                return res
        end
@@ -470,7 +486,6 @@ class NaiveInterpreter
                        exprs.add e
                end
 
-
                # Fill `res` with the result of the evaluation according to the mapping
                for i in [0..msignature.arity[ do
                        var param = msignature.mparameters[i]
@@ -684,17 +699,31 @@ class NaiveInterpreter
        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
        # ASSERT: not self.mtype.is_anchored
        var mtype: MType
 
-       # return true if the instance is the true value.
-       # return false if the instance is the true value.
-       # else aborts
+       # Return `true` if the instance is the `true` value.
+       #
+       # Return `false` if the instance is the `false` value.
+       # Abort if the instance is not a boolean value.
        fun is_true: Bool do abort
 
+       # Return `true` if the instance is null.
+       # Return `false` otherwise.
+       fun is_null: Bool do return mtype isa MNullType
+
        # Return true if `self` IS `o` (using the Nit semantic of is)
        fun eq_is(o: Instance): Bool do return self.is_same_instance(o)
 
@@ -747,7 +776,7 @@ class MutableInstance
 end
 
 # Special instance to handle primitives values (int, bool, etc.)
-# The trick it just to encapsulate the <<real>> value
+# The trick is just to encapsulate the “real” value.
 class PrimitiveInstance[E]
        super Instance
 
@@ -811,7 +840,7 @@ class InterpreterFrame
        super Frame
 
        # Mapping between a variable and the current value
-       private var map: Map[Variable, Instance] = new HashMap[Variable, Instance]
+       var map: Map[Variable, Instance] = new HashMap[Variable, Instance]
 end
 
 redef class ANode
@@ -819,7 +848,13 @@ redef class ANode
        # `v` is used to know if a colored message is displayed or not
        fun fatal(v: NaiveInterpreter, message: String)
        do
-               if v.modelbuilder.toolcontext.opt_no_color.value == true then
+               # 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 then
                        sys.stderr.write("Runtime error: {message} ({location.file.filename}:{location.line_start})\n")
                else
                        sys.stderr.write("{location}: Runtime error: {message}\n{location.colored_line("0;31")}\n")
@@ -854,7 +889,10 @@ redef class AMethPropdef
                return res
        end
 
-       private fun call_commons(v: NaiveInterpreter, mpropdef: MMethodDef, arguments: Array[Instance], f: Frame): nullable Instance
+       # Execution of the body of the method
+       #
+       # It handle the common special cases: super, intern, extern
+       fun call_commons(v: NaiveInterpreter, mpropdef: MMethodDef, arguments: Array[Instance], f: Frame): nullable Instance
        do
                v.frames.unshift(f)
 
@@ -940,7 +978,7 @@ redef class AMethPropdef
                else if pname == "native_class_name" then
                        var recv = args.first
                        var txt = recv.mtype.to_s
-                       return v.native_string_instance(txt)
+                       return v.c_string_instance(txt)
                else if pname == "==" then
                        # == is correctly redefined for instances
                        return v.bool_instance(args[0] == args[1])
@@ -950,6 +988,8 @@ redef class AMethPropdef
                        return v.bool_instance(args[0].mtype == args[1].mtype)
                else if pname == "is_same_instance" then
                        return v.bool_instance(args[0].eq_is(args[1]))
+               else if pname == "class_inheritance_metamodel_json" then
+                       return v.c_string_instance(v.mainmodule.flatten_mclass_hierarchy.to_thin_json)
                else if pname == "exit" then
                        exit(args[1].to_i)
                        abort
@@ -1145,21 +1185,21 @@ redef class AMethPropdef
                        else if pname == "round" then
                                return v.float_instance(args[0].to_f.round)
                        end
-               else if cname == "NativeString" then
+               else if cname == "CString" then
                        if pname == "new" then
-                               return v.native_string_instance_len(args[1].to_i)
+                               return v.c_string_instance_len(args[1].to_i)
                        end
-                       var recvval = args.first.val.as(NativeString)
+                       var recvval = args.first.val.as(CString)
                        if pname == "[]" then
                                var arg1 = args[1].to_i
-                               return v.byte_instance(recvval[arg1])
+                               return v.int_instance(recvval[arg1])
                        else if pname == "[]=" then
                                var arg1 = args[1].to_i
-                               recvval[arg1] = args[2].val.as(Byte)
+                               recvval[arg1] = args[2].val.as(Int)
                                return null
                        else if pname == "copy_to" then
-                               # sig= copy_to(dest: NativeString, length: Int, from: Int, to: Int)
-                               var destval = args[1].val.as(NativeString)
+                               # sig= copy_to(dest: CString, length: Int, from: Int, to: Int)
+                               var destval = args[1].val.as(CString)
                                var lenval = args[2].to_i
                                var fromval = args[3].to_i
                                var toval = args[4].to_i
@@ -1168,14 +1208,13 @@ redef class AMethPropdef
                        else if pname == "atoi" then
                                return v.int_instance(recvval.atoi)
                        else if pname == "fast_cstring" then
-                               var ns = recvval.fast_cstring(args[1].to_i)
-                               return v.native_string_instance(ns.to_s)
+                               return v.c_string_instance_fast_cstr(args[0].val.as(CString), args[1].to_i)
                        else if pname == "fetch_4_chars" then
-                               return v.int_instance(args[0].val.as(NativeString).fetch_4_chars(args[1].to_i))
+                               return v.uint32_instance(args[0].val.as(CString).fetch_4_chars(args[1].to_i))
                        else if pname == "fetch_4_hchars" then
-                               return v.int_instance(args[0].val.as(NativeString).fetch_4_hchars(args[1].to_i))
+                               return v.uint32_instance(args[0].val.as(CString).fetch_4_hchars(args[1].to_i))
                        else if pname == "utf8_length" then
-                               return v.int_instance(args[0].val.as(NativeString).utf8_length(args[1].to_i, args[2].to_i))
+                               return v.int_instance(args[0].val.as(CString).utf8_length(args[1].to_i, args[2].to_i))
                        end
                else if cname == "NativeArray" then
                        if pname == "new" then
@@ -1465,7 +1504,7 @@ redef class AMethPropdef
                        return v.int_instance(v.arguments.length)
                else if pname == "native_argv" then
                        var txt = v.arguments[args[1].to_i]
-                       return v.native_string_instance(txt)
+                       return v.c_string_instance(txt)
                else if pname == "lexer_goto" then
                        return v.int_instance(lexer_goto(args[1].to_i, args[2].to_i))
                else if pname == "lexer_accept" then
@@ -1493,7 +1532,7 @@ redef class AAttrPropdef
                else if mpropdef == mwritepropdef then
                        assert args.length == 2
                        var arg = args[1]
-                       if is_optional and arg.mtype isa MNullType then
+                       if is_optional and arg.is_null then
                                var f = v.new_frame(self, mpropdef, args)
                                arg = evaluate_expr(v, recv, f)
                        end
@@ -1677,6 +1716,8 @@ redef class AEscapeExpr
                        var i = v.expr(ne)
                        if i == null then return
                        v.escapevalue = i
+               else
+                       v.escapevalue = null
                end
                v.escapemark = self.escapemark
        end
@@ -1685,13 +1726,8 @@ end
 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
 
@@ -1791,7 +1827,7 @@ redef class AForExpr
                for g in n_groups do
                        var col = v.expr(g.n_expr)
                        if col == null then return
-                       if col.mtype isa MNullType then fatal(v, "Receiver is null")
+                       if col.is_null then fatal(v, "Receiver is null")
 
                        var iter = v.callsite(g.method_iterator, [col]).as(not null)
                        iters.add iter
@@ -1858,6 +1894,22 @@ redef class AAssertExpr
                if not cond.is_true then
                        v.stmt(self.n_else)
                        if v.is_escaping then return
+
+                       # Explain assert if it fails
+                       var explain_assert_str = explain_assert_str
+                       if explain_assert_str != null then
+                               var i = v.expr(explain_assert_str)
+                               if i isa MutableInstance then
+                                       var res = v.send(v.force_get_primitive_method("to_cstring", i.mtype), [i])
+                                       if res != null then
+                                               var val = res.val
+                                               if val != null then
+                                                       print_error "Runtime assert: {val.to_s}"
+                                               end
+                                       end
+                               end
+                       end
+
                        var nid = self.n_id
                        if nid != null then
                                fatal(v, "Assert '{nid.text}' failed")
@@ -1942,8 +1994,9 @@ end
 redef class ACharExpr
        redef fun expr(v)
        do
-               if is_ascii then return v.byte_instance(self.value.as(not null).ascii)
-               if is_code_point then return v.int_instance(self.value.as(not null).code_point)
+               if is_code_point then
+                       return v.int_instance(self.value.as(not null).code_point)
+               end
                return v.char_instance(self.value.as(not null))
        end
 end
@@ -2016,7 +2069,7 @@ redef class AStringExpr
                var s = v.string_instance(value)
                if is_string then return s
                if is_bytestring then
-                       var ns = v.native_string_instance_from_ns(bytes.items, bytes.length)
+                       var ns = v.c_string_instance_from_ns(bytes.items, bytes.length)
                        var ln = v.int_instance(bytes.length)
                        var prop = to_bytes_with_copy
                        assert prop != null
@@ -2135,7 +2188,7 @@ redef class AAsNotnullExpr
        do
                var i = v.expr(self.n_expr)
                if i == null then return null
-               if i.mtype isa MNullType then
+               if i.is_null then
                        fatal(v, "Cast failed")
                end
                return i
@@ -2168,6 +2221,12 @@ redef class ASendExpr
        do
                var recv = v.expr(self.n_expr)
                if recv == null then return null
+
+               # Safe call shortcut if recv is null
+               if is_safe and recv.is_null then
+                       return recv
+               end
+
                var args = v.varargize(callsite.mpropdef, callsite.signaturemap, recv, self.raw_arguments)
                if args == null then return null
 
@@ -2176,6 +2235,14 @@ redef class ASendExpr
        end
 end
 
+redef class ACallrefExpr
+        redef fun expr(v)
+        do
+                fatal(v, "NOT YET IMPLEMENTED callref expressions.")
+                return null
+        end
+end
+
 redef class ASendReassignFormExpr
        redef fun stmt(v)
        do
@@ -2264,7 +2331,7 @@ redef class AAttrExpr
        do
                var recv = v.expr(self.n_expr)
                if recv == null then return null
-               if recv.mtype isa MNullType then fatal(v, "Receiver is null")
+               if recv.is_null then fatal(v, "Receiver is null")
                var mproperty = self.mproperty.as(not null)
                return v.read_attribute(mproperty, recv)
        end
@@ -2275,7 +2342,7 @@ redef class AAttrAssignExpr
        do
                var recv = v.expr(self.n_expr)
                if recv == null then return
-               if recv.mtype isa MNullType then fatal(v, "Receiver is null")
+               if recv.is_null then fatal(v, "Receiver is null")
                var i = v.expr(self.n_value)
                if i == null then return
                var mproperty = self.mproperty.as(not null)
@@ -2288,7 +2355,7 @@ redef class AAttrReassignExpr
        do
                var recv = v.expr(self.n_expr)
                if recv == null then return
-               if recv.mtype isa MNullType then fatal(v, "Receiver is null")
+               if recv.is_null then fatal(v, "Receiver is null")
                var value = v.expr(self.n_value)
                if value == null then return
                var mproperty = self.mproperty.as(not null)
@@ -2304,7 +2371,7 @@ redef class AIssetAttrExpr
        do
                var recv = v.expr(self.n_expr)
                if recv == null then return null
-               if recv.mtype isa MNullType then fatal(v, "Receiver is null")
+               if recv.is_null then fatal(v, "Receiver is null")
                var mproperty = self.mproperty.as(not null)
                return v.bool_instance(v.isset_attribute(mproperty, recv))
        end
@@ -2317,6 +2384,13 @@ redef class AVarargExpr
        end
 end
 
+redef class ASafeExpr
+       redef fun expr(v)
+       do
+               return v.expr(self.n_expr)
+       end
+end
+
 redef class ANamedargExpr
        redef fun expr(v)
        do