Class: Idl::UnaryOperatorExpressionAst

Inherits:
AstNode
  • Object
show all
Includes:
Rvalue
Defined in:
lib/idlc/ast.rb,
lib/idlc/passes/prune.rb,
lib/idlc/passes/gen_adoc.rb

Overview

represents a unary operator

for example:

-value
~value
!bool_variable

Constant Summary

Constants inherited from AstNode

AstNode::Bits1Type, AstNode::Bits32Type, AstNode::Bits64Type, AstNode::BoolType, AstNode::ConstBoolType, AstNode::PossiblyUnknownBits1Type, AstNode::PossiblyUnknownBits32Type, AstNode::PossiblyUnknownBits64Type, AstNode::ReachableFunctionCacheType, AstNode::StringType, AstNode::VoidType

Instance Attribute Summary

Attributes inherited from AstNode

#children, #input, #interval, #parent

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Rvalue

#max_value, #min_value, #truncate, #values

Methods inherited from AstNode

#always_terminates?, #declaration?, #executable?, extract_base_var_name, #find_ancestor, #find_dst_registers, #find_referenced_csrs, #find_src_registers, #freeze_tree, #gen_option_adoc, #input_file, input_from_source_yaml, #inspect, #internal_error, interval_from_source_yaml, #lineno, #lines_around, #nullify_assignments, #pass_find_return_values, #path, #print_ast, #reachable_exceptions, #reachable_functions, #set_input_file, #set_input_file_unless_already_set, #source_line_file_offsets, #source_starting_offset, #source_yaml, #starting_line, #text_value, #truncation_warn, #type_error, #unindent, value_else, #value_else, value_error, #value_error, value_try, #value_try, write_back_nested

Constructor Details

#initialize(input, interval, op, expression) ⇒ UnaryOperatorExpressionAst

Returns a new instance of UnaryOperatorExpressionAst.



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# File 'lib/idlc/ast.rb', line 6192

def initialize(input, interval, op, expression)
  super(input, interval, [expression])

  raise "Bad op #{op.inspect}" unless ["~", "!", "-"].include?(op)
  @op = op
end

Class Method Details

.from_h(yaml, source_mapper) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6304

def self.from_h(yaml, source_mapper)
  raise "Bad YAML" unless yaml.key?("kind") && yaml.fetch("kind") == "unary_operator_expr"

  input = input_from_source_yaml(yaml.fetch("source"), source_mapper)
  interval = interval_from_source_yaml(yaml.fetch("source"))
  UnaryOperatorExpressionAst.new(
    input, interval,
    yaml.fetch("op"),
    AstNode.from_h(yaml.fetch("expr"), source_mapper)
  )
end

Instance Method Details

#const_eval?(symtab) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/idlc/ast.rb', line 6188

def const_eval?(symtab) = expression.const_eval?(symtab)

#exp ⇒ AstNode

Returns the operated-on expression.

Returns:

  • (AstNode) —

    the operated-on expression



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# File 'lib/idlc/ast.rb', line 6282

def exp
  expression
end

#expression ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6190

def expression = @children[0]

#gen_adoc(indent = 0, indent_spaces: 2) ⇒ Object 



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# File 'lib/idlc/passes/gen_adoc.rb', line 270

def gen_adoc(indent = 0, indent_spaces: 2)
  "#{' ' * indent}#{op}#{exp.gen_adoc(0, indent_spaces:)}"
end

#invert(symtab) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6199

def invert(symtab)
  unless symtab.nil?
    type_error "Not a boolean operator" unless type(symtab).kind == :boolean
  end

  type_error "Invert only works with !" unless op == "!"

  expression
end

#op ⇒ String

Returns The operator.

Returns:

  • (String) —

    The operator



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# File 'lib/idlc/ast.rb', line 6287

def op
  @op
end

#prune(symtab, forced_type: nil) ⇒ Object 



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# File 'lib/idlc/passes/prune.rb', line 791

def prune(symtab, forced_type: nil)
  value_result = value_try do
    v = value(symtab)
    if type(symtab).kind == :bits
      if type(symtab).width == :unknown
        value_error "Unknown width"
      end
    end
    return PruneHelpers.create_literal(symtab, v, type(symtab), forced_type: forced_type || type(symtab))
  end
  value_else(value_result) do
    UnaryOperatorExpressionAst.new(input, interval, @op, exp.prune(symtab, forced_type:))
  end
end

#to_h ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6296

def to_h = {
  "kind" => "unary_operator_expr",
  "op" => op,
  "expr" => expression.to_h,
  "source" => source_yaml
}

#to_idl ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6293

def to_idl = "#{op}#{expression.to_idl}"

#type(symtab) ⇒ Type

Given a specific symbol table, return the type of this node.

Should not be called until #type_check is called with the same arguments

Parameters:

Returns:

  • (Type) —

    The type of the node

Raises:



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# File 'lib/idlc/ast.rb', line 6210

def type(symtab)
  case op
  when "-", "~"
    exp.type(symtab).clone
  when "!"
    if exp.type(symtab).const?
      ConstBoolType
    else
      BoolType
    end
  else
    internal_error "unhandled op #{op}"
  end
end

#type_check(symtab, strict:) ⇒ void

This method returns an undefined value.

type check this node and all children

Calls to #type and/or #value may depend on type_check being called first with the same symtab. If not, those functions may raise an AstNode::InternalError

Parameters:

Raises:



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# File 'lib/idlc/ast.rb', line 6226

def type_check(symtab, strict:)
  exp.type_check(symtab, strict:)

  case op
  when "-"
    unless [:bits, :bitfield].include?(exp.type(symtab).kind)
      type_error "#{exp.type(symtab)} does not support unary #{op} operator"
    end

    # type_error "Unary minus only works on signed values" unless exp.type(symtab).signed?
  when "~"
    unless [:bits, :bitfield].include?(exp.type(symtab).kind)
      type_error "#{exp.type(symtab)} does not support unary #{op} operator"
    end
  when "!"
    unless exp.type(symtab).convertable_to?(:boolean)
      if exp.type(symtab).kind == :bits
        type_error "#{exp.type(symtab)} does not support unary #{op} operator. Perhaps you want '#{exp.text_value} != 0'?"
      else
        type_error "#{exp.type(symtab)} does not support unary #{op} operator"
      end
    end
  else
    internal_error "Unhandled op #{op}"
  end
end

#value(symtab) ⇒ Object

Return the compile-time-known value of the node



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# File 'lib/idlc/ast.rb', line 6254

def value(symtab)
  val = val_trunc =
    case op
    when "-"
      -exp.value(symtab)
    when "~"
      ~exp.value(symtab)
    when "!"
      !exp.value(symtab)
    else
      internal_error "Unhandled unary op #{op}"
    end
  t = type(symtab)
  if t.integral?
    if t.width == :unknown
      value_error("Unknown width for truncation")
    end
    val_trunc = truncate(val, t.width, t.signed?)
  end

  if op != "~"
    truncation_warn "#{text_value} is truncated due to insufficient bit width (from #{val} to #{val_trunc})" if val_trunc != val
  end

  val_trunc
end