src/auto_super_init.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2012 Jean Privat <jean@pryen.org>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # Computing of super-constructors that must be implicitely called at the begin of constructors.
  18 # The current rules are a bit crazy but whatever.
  19 module auto_super_init
  20
  21 import typing
  22 import modelbuilder
  23 import phase
  24
  25 redef class ToolContext
  26         var auto_super_init_phase: Phase = new AutoSuperInitPhase(self, [typing_phase])
  27 end
  28
  29 private class AutoSuperInitPhase
  30         super Phase
  31         redef fun process_npropdef(npropdef) do if npropdef isa AConcreteMethPropdef then npropdef.do_auto_super_init(toolcontext.modelbuilder)
  32 end
  33
  34 private class AutoSuperInitVisitor
  35         super Visitor
  36         init
  37         do
  38         end
  39
  40         redef fun visit(n)
  41         do
  42                 n.accept_auto_super_init(self)
  43                 n.visit_all(self)
  44         end
  45
  46         var has_explicit_super_init: Bool = false
  47 end
  48
  49
  50 redef class AConcreteMethPropdef
  51         # In case of constructor, the list of implicit auto super init constructors invoked (if needed)
  52         var auto_super_inits: nullable Array[MMethod] = null
  53
  54         fun do_auto_super_init(modelbuilder: ModelBuilder)
  55         do
  56                 var mclassdef = self.parent.as(AClassdef).mclassdef.as(not null)
  57                 var mpropdef = self.mpropdef.as(not null)
  58                 var mmodule = mpropdef.mclassdef.mmodule
  59
  60                 # Collect only for constructors
  61                 if not mpropdef.mproperty.is_init then return
  62
  63                 # FIXME: THIS IS STUPID (be here to keep the old code working)
  64                 if not mpropdef.mclassdef.is_intro then return
  65
  66                 # Do we inherit for a constructor?
  67                 var skip = true
  68                 for cd in mclassdef.in_hierarchy.direct_greaters do
  69                         if cd.mclass.kind.need_init then skip = false
  70                 end
  71                 if skip then return
  72
  73                 # Now we search for the absence of any explicit super-init invocation
  74                 #  * via a "super"
  75                 #  * via a call of an other init
  76                 var nblock = self.n_block
  77                 if nblock != null then
  78                         var v = new AutoSuperInitVisitor
  79                         v.enter_visit(nblock)
  80                         if v.has_explicit_super_init then return
  81                 end
  82
  83                 # Still here? So it means that we must determine what super inits need to be automatically invoked
  84
  85                 var auto_super_inits = new Array[MMethod]
  86                 for msupertype in mclassdef.supertypes do
  87                         # FIXME: the order is quite arbitrary
  88                         if not msupertype.mclass.kind.need_init then continue
  89                         msupertype = msupertype.anchor_to(mmodule, mclassdef.bound_mtype)
  90                         var candidate = modelbuilder.try_get_mproperty_by_name2(self, mmodule, msupertype, mpropdef.mproperty.name)
  91                         if candidate == null then
  92                                 candidate = modelbuilder.try_get_mproperty_by_name2(self, mmodule, msupertype, "init")
  93                         end
  94                         if candidate == null then
  95                                 modelbuilder.error(self, "Cannot do an implicit constructor call for {mpropdef}: there is no costructor named {mpropdef.mproperty.name} in {msupertype}.")
  96                                 return
  97                         end
  98                         assert candidate isa MMethod
  99                         auto_super_inits.add(candidate)
 100                 end
 101                 if auto_super_inits.is_empty then
 102                         modelbuilder.error(self, "No constructors to call implicitely. Call one explicitely.")
 103                         return
 104                 end
 105                 for auto_super_init in auto_super_inits do
 106                         var auto_super_init_def = auto_super_init.intro
 107                         var msig = mpropdef.msignature.as(not null)
 108                         var supermsig = auto_super_init_def.msignature.as(not null)
 109                         if auto_super_init_def.msignature.arity != 0 and auto_super_init_def.msignature.arity != mpropdef.msignature.arity then
 110                                 # TODO: Better check of the signature
 111                                 modelbuilder.error(self, "Problem with signature of constructor {auto_super_init_def}{supermsig}. Expected {msig}")
 112                         end
 113                 end
 114                 self.auto_super_inits = auto_super_inits
 115         end
 116
 117 end
 118
 119 redef class ANode
 120         private fun accept_auto_super_init(v: AutoSuperInitVisitor) do end
 121 end
 122
 123
 124 redef class ASendExpr
 125         redef fun accept_auto_super_init(v)
 126         do
 127                 var mproperty = self.mproperty
 128                 if mproperty == null then return
 129                 if mproperty.is_init then
 130                         v.has_explicit_super_init = true
 131                 end
 132         end
 133 end
 134
 135 redef class ASuperExpr
 136         redef fun accept_auto_super_init(v)
 137         do
 138                 # If the super is a standard call-next-method then there it is considered am explicit super init call
 139                 # The the super is a "super int" then it is also an explicit super init call
 140                 v.has_explicit_super_init = true
 141         end
 142 end