DebugCheckArrayBounds

Checks at run time that the shapes in an array assignment conform.

Declaration

Syntax

DebugCheckArrayBounds(expr target, expr* components,
    bool move_allocation)

Arguments

Argument	Description
target	the array being assigned to.
components	the array operands of the right hand side, whose shapes must match target.
move_allocation	true when the assignment it guards moves an allocation instead of copying.

Return values

None.

Description

This node is inserted by the array_op pass ahead of an array assignment when bounds checking is enabled, and it is never produced by a frontend. It fails at run time with a diagnostic naming the mismatching extents rather than writing out of bounds.

Each element of components must itself be an array: the check compares the extents of the target against the extents of the operands the assignment reads.

Examples

(DebugCheckArrayBounds
  :target (Var
    :v (SymbolRef 1 "a")
  )
  :components [
    (Var
      :v (SymbolRef 1 "b")
    )
  ]
  :move_allocation false
)

It comes from this complete ASR text document:

(TranslationUnit
  :symtab (SymbolTable
    :id 0
    :symbols {
      "main" (Program
        :symtab (SymbolTable
          :id 1
          :symbols {
            "a" (Variable
              :parent_symtab 1
              :name "a"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Array
                :type (Integer
                  :kind 4
                )
                :dims [
                  (dimension
                    :start (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :length (IntegerConstant
                      :n 3
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :physical_type :FixedSizeArray
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "b" (Variable
              :parent_symtab 1
              :name "b"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Array
                :type (Integer
                  :kind 4
                )
                :dims [
                  (dimension
                    :start (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :length (IntegerConstant
                      :n 3
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :physical_type :FixedSizeArray
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
          }
        )
        :name "main"
        :dependencies []
        :body [
          (DebugCheckArrayBounds
            :target (Var
              :v (SymbolRef 1 "a")
            )
            :components [
              (Var
                :v (SymbolRef 1 "b")
              )
            ]
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "a")
            )
            :value (Var
              :v (SymbolRef 1 "b")
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
        ]
      )
    }
  )
  :items []
)

See Also

Assignment, ArraySize, ArrayBound