Class: Idl::CsrReadExpressionAst

Inherits:
AstNode
  • Object
show all
Includes:
Rvalue
Defined in:
lib/idl/ast.rb

Instance Method Summary collapse

Constructor Details

#initialize(input, interval, idx) ⇒ CsrReadExpressionAst

Returns a new instance of CsrReadExpressionAst.



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# File 'lib/idl/ast.rb', line 5867

def initialize(input, interval, idx)
  if idx.is_a?(AstNode)
    super(input, interval, [idx])
  else
    super(input, interval, EMPTY_ARRAY)
  end

  @idx = idx
end

Instance Method Details

#csr_def(symtab) ⇒ Object 



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# File 'lib/idl/ast.rb', line 5927

def csr_def(symtab)
  cfg_arch = symtab.cfg_arch
  idx_text = @idx.is_a?(String) ? @idx : @idx.text_value
  csr = cfg_arch.csr(idx_text)
  if !csr.nil?
    # this is a known csr name
    csr
  else
    # this is an expression
    value_result = value_try do
      idx_value = @idx.value(symtab)
      return cfg_arch.csrs.find { |csr| csr.address == idx_value }
    end
    # || we don't know at compile time which CSR this is...
    nil
  end
end

#csr_known?(symtab) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/idl/ast.rb', line 5945

def csr_known?(symtab)
  !csr_def(symtab).nil?
end

#csr_name(symtab) ⇒ Object 



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# File 'lib/idl/ast.rb', line 5949

def csr_name(symtab)
  internal_error "No CSR" unless csr_known?(symtab)

  csr_def(symtab).name
end

#freeze_tree(symtab) ⇒ Object 



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# File 'lib/idl/ast.rb', line 5877

def freeze_tree(symtab)
  return if frozen?

  @cfg_arch = symtab.cfg_arch # remember cfg_arch, used by gen_adoc pass
  @idx.freeze_tree(symtab)
  freeze
end

#to_idl ⇒ String

Return valid IDL representation of the node (and its subtree)

Returns:

  • (String) —

    IDL code for the node



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# File 'lib/idl/ast.rb', line 5970

def to_idl = "CSR[#{@idx.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/idl/ast.rb', line 5886

def type(symtab)
  cfg_arch = symtab.cfg_arch

  cd = csr_def(symtab)
  if cd.nil?
    # we don't know anything about this index, so we can only
    # treat this as a generic
    if symtab.mxlen == 32
      Bits32Type
    else
      Bits64Type
    end
  else
    CsrType.new(cd, cfg_arch)
  end
end

#type_check(symtab) ⇒ 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/idl/ast.rb', line 5904

def type_check(symtab)
  cfg_arch = symtab.cfg_arch

  idx_text = @idx.is_a?(String) ? @idx : @idx.text_value
  if !cfg_arch.csr(idx_text).nil?
    # this is a known csr name
    # nothing else to check

  else
    # this is an expression
    @idx.type_check(symtab)
    type_error "Csr index must be integral" unless @idx.type(symtab).integral?

    value_result = value_try do
      idx_value = @idx.value(symtab)
      csr_index = cfg_arch.csrs.index { |csr| csr.address == idx_value }
      type_error "No csr number '#{idx_value}' was found" if csr_index.nil?
      :ok
    end
    # OK, index doesn't have to be known
  end
end

#value(symtab) ⇒ Object

Return the compile-time-known value of the node



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# File 'lib/idl/ast.rb', line 5956

def value(symtab)
  cd = csr_def(symtab)
  value_error "CSR number not knowable" if cd.nil?
  if symtab.cfg_arch.fully_configured?
    value_error "CSR is not implemented" unless symtab.cfg_arch.transitive_implemented_csrs.any? { |icsr| icsr.name == cd.name }
  else
    value_error "CSR is not defined" unless symtab.cfg_arch.csrs.any? { |icsr| icsr.name == cd.name }
  end
  cd.fields.each { |f| value_error "#{csr_name(symtab)}.#{f.name} not RO" unless f.type(symtab) == "RO" }

  csr_def(symtab).fields.reduce(0) { |val, f| val | (f.value << f.location.begin) }
end

#values(symtab) ⇒ Array<Integer>, ... Originally defined in module Rvalue

Return a complete list of possible compile-time-known values of the node, or raise a ValueError if the full list cannot be determined

For most AstNodes, this will just be a single-entry array

Parameters:

  • symtab (SymbolTable) —

    The context for the evaluation

Returns:

  • (Array<Integer>) —

    The complete list of compile-time-known values, when they are integral

  • (Array<Boolean>) —

    The complete list of compile-time-known values, when they are booleans

  • (AstNode::ValueError) —

    if the list of values is not knowable at compile time