--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2015 Julien Pagès <julien.pages@lirmm.fr>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Handle all numbering operations related to local variables in the Nit virtual machine
+module variables_numbering
+
+import vm
+
+redef class VirtualMachine
+
+ # Number the variables in `n`.
+ # Do nothing if `n` is null
+ fun numbering(n: nullable AExpr, position: Int): Int
+ do
+ if n == null then return position
+
+ var pos = n.numbering(self, position)
+ return pos
+ end
+end
+
+redef class Variable
+ # The position in the environment
+ var position: Int
+end
+
+redef class AExpr
+ # Give a position to each variable declared in the node.
+ # NOTE: Do not call this method directly, but use `v.numbering`
+ # This method is here to be implemented by subclasses.
+ # *`v` The current instance of the virtual machine
+ # *`position` The first available position in the environment a variable can have
+ # Return the next available position a variable can have
+ public fun numbering(v: VirtualMachine, position: Int): Int
+ do
+ return position
+ end
+end
+
+redef class APropdef
+ # Indicate if the variables numbering has been done
+ private var is_numbering: Bool = false
+
+ # The size of the environment to create to call this method
+ private var environment_size: Int = 0
+end
+
+redef class AMethPropdef
+ # Assign a position in the environment to each local variable of `mpropdef`
+ # *`v` The current VirtualMachine
+ # *`mpropdef` The method to number
+ private fun numbering_variables(v: VirtualMachine, mpropdef: MMethodDef)
+ do
+ # The position in the environment
+ var position = 0
+
+ # The `self` variable has the first position
+ if self.selfvariable != null then
+ self.selfvariable.position = position
+ position += 1
+ end
+
+ # Number the parameters
+ for i in [0..mpropdef.msignature.arity[ do
+ var variable = self.n_signature.n_params[i].variable
+ variable.as(not null).position = position
+ position += 1
+ end
+
+ # Recursively go into the AST nodes to number all local variables
+ if n_block != null then
+ position = v.numbering(self.n_block, position)
+ end
+
+ is_numbering = true
+
+ # The size of the environment to create to execute a call to this method
+ environment_size = position
+ end
+end
+
+redef class AAttrPropdef
+ # Assign a position in the environment to each local variable of `mpropdef`
+ # *`v` The current VirtualMachine
+ private fun numbering_variables(v: VirtualMachine)
+ do
+ # The position in the environment
+ var position = 0
+
+ # The `self` variable has the first position
+ if self.selfvariable != null then
+ self.selfvariable.position = position
+ position += 1
+ end
+
+ # Recursively go into the AST nodes to number all local variables
+ if n_block != null then
+ position = v.numbering(self.n_block, position)
+ end
+
+ is_numbering = true
+
+ # The size of the environment to create to execute a call to this method
+ environment_size = position
+ end
+end
+
+redef class AVardeclExpr
+ redef fun numbering(v, position)
+ do
+ # Attribute a position to this variable
+ self.variable.as(not null).position = position
+ position += 1
+
+ # Recursively continue to numbering the variables
+ position = v.numbering(self.n_expr, position)
+
+ # `position` is the next available position in the environment
+ return position
+ end
+end
+
+redef class ABlockExpr
+ redef fun numbering(v, position)
+ do
+ for e in self.n_expr do
+ position = v.numbering(e, position)
+ end
+ return position
+ end
+end
+
+redef class AIfExpr
+ redef fun numbering(v, position)
+ do
+ # Attribute numbers separetely for the two branches
+ var pos = v.numbering(self.n_then, position)
+ var pos1 = v.numbering(self.n_else, position)
+
+ if pos > pos1 then
+ return pos
+ else
+ return pos1
+ end
+ end
+end
+
+redef class AIfexprExpr
+ redef fun numbering(v, position)
+ do
+ # Attribute numbers separetely for the two branches
+ var pos = v.numbering(self.n_then, position)
+ var pos1 = v.numbering(self.n_else, position)
+
+ if pos > pos1 then
+ return pos
+ else
+ return pos1
+ end
+ end
+end
+
+redef class ADoExpr
+ redef fun numbering(v, position)
+ do
+ return v.numbering(self.n_block, position)
+ end
+end
+
+redef class AWhileExpr
+ redef fun numbering(v, position)
+ do
+ return v.numbering(self.n_block, position)
+ end
+end
+
+redef class ALoopExpr
+ redef fun numbering(v, position)
+ do
+ return v.numbering(self.n_block, position)
+ end
+end
+
+redef class AForExpr
+ redef fun numbering(v, position)
+ do
+ # Give a position to each variable declared in the header of the for
+ if self.variables.length == 1 then
+ self.variables.first.position = position
+ self.variables[0].position = position
+ position += 1
+ else if self.variables.length == 2 then
+ self.variables[0].position = position
+ position += 1
+ self.variables[1].position = position
+ position += 1
+ end
+ return v.numbering(self.n_block, position)
+ end
+end
+
+redef class AArrayExpr
+ redef fun numbering(v, position)
+ do
+ for nexpr in self.n_exprs do
+ position = v.numbering(nexpr, position)
+ end
+ return position
+ end
+end
nitlanguage / nit.git / commitdiff