Class: Idl::SymbolTable

Inherits:
Object
  • Object
show all
Defined in:
lib/idl/symbol_table.rb

Overview

scoped symbol table holding known symbols at a current point in parsing

Defined Under Namespace

Classes: DuplicateSymError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(arch_def, effective_xlen = nil) ⇒ SymbolTable

Returns a new instance of SymbolTable.



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# File 'lib/idl/symbol_table.rb', line 92

def initialize(arch_def, effective_xlen = nil)
  @archdef = arch_def
  if arch_def.fully_configured?
    raise "effective_xlen should not be set when symbol table is given a fully-configured ArchDef" unless effective_xlen.nil?
  else
    raise "effective_xlen should be set when symbol table is given an ArchDef" if effective_xlen.nil? && arch_def.mxlen.nil?
  end
  @mxlen = effective_xlen.nil? ? arch_def.mxlen : effective_xlen
  @callstack = [nil]
  @scopes = [{
    "X" => Var.new(
      "X",
      Type.new(:array, sub_type: XregType.new(@mxlen), width: 32, qualifiers: [:global])
    ),
    "XReg" => XregType.new(@mxlen),
    "Boolean" => Type.new(:boolean),
    "true" => Var.new(
      "true",
      Type.new(:boolean),
      true
    ),
    "false" => Var.new(
      "false",
      Type.new(:boolean),
      false
    )

  }]
  arch_def.params_with_value.each do |param_with_value|
    type = Type.from_json_schema(param_with_value.schema).make_const
    if type.kind == :array && type.width == :unknown
      type = Type.new(:array, width: param_with_value.value.length, sub_type: type.sub_type, qualifiers: [:const])
    end

    # could already be present...
    existing_sym = get(param_with_value.name)
    if existing_sym.nil?
      add!(param_with_value.name, Var.new(param_with_value.name, type, param_with_value.value))
    else
      unless existing_sym.type.equal_to?(type) && existing_sym.value == param_with_value.value
        raise DuplicateSymError, "Definition error: Param #{param.name} is defined by multiple extensions and is not the same definition in each"
      end
    end
  end
  # now add all parameters, even those not implemented
  arch_def.params_without_value.each do |param|
    if param.exts.size == 1
      if param.name == "XLEN"
        # special case: we actually do know XLEN
        add!(param.name, Var.new(param.name, param.idl_type.clone.make_const, @mxlen))
      else
        add!(param.name, Var.new(param.name, param.idl_type.clone.make_const))
      end
    else
      # could already be present...
      existing_sym = get(param.name)
      if existing_sym.nil?
        add!(param.name, Var.new(param.name, param.idl_type.clone.make_const))
      else
        unless existing_sym.type.equal_to?(param.idl_type)
          raise "Definition error: Param #{param.name} is defined by multiple extensions and is not the same definition in each"
        end
      end
    end
  end

  # add the builtin extensions
  # add!(
  #   "ExtensionName",
  #   EnumerationType.new(
  #     "ExtensionName",
  #     arch_def.extensions.map(&:name),
  #     Array.new(arch_def.extensions.size) { |i| i + 1 }
  #   )
  # )
  # add!(
  #   "ExceptionCode",
  #   EnumerationType.new(
  #     "ExceptionCode",
  #     arch_def.exception_codes.map(&:var),
  #     arch_def.exception_codes.map(&:num)
  #   )
  # )
  # add!(
  #   "InterruptCode",
  #   EnumerationType.new(
  #     "InterruptCode",
  #     arch_def.interrupt_codes.map(&:var),
  #     arch_def.interrupt_codes.map(&:num)
  #   )
  # )
end

Instance Attribute Details

#archdef ⇒ Object (readonly)

Returns the value of attribute archdef.



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# File 'lib/idl/symbol_table.rb', line 78

def archdef
  @archdef
end

#mxlen ⇒ Integer (readonly)

Returns 32 or 64, the XLEN in M-mode.

Returns:

  • (Integer) —

    32 or 64, the XLEN in M-mode



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# File 'lib/idl/symbol_table.rb', line 81

def mxlen
  @mxlen
end

Instance Method Details

#add(name, var) ⇒ Object

add a new symbol at the outermost scope

Parameters:

  • name (#to_s) —

    Symbol name

  • var (Object) —

    Symbol object (usually a Var or a Type)



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# File 'lib/idl/symbol_table.rb', line 309

def add(name, var)
  @scopes.last[name] = var
end

#add!(name, var) ⇒ Object

add a new symbol at the outermost scope, unless that symbol is already defined

Parameters:

  • name (#to_s) —

    Symbol name

  • var (Object) —

    Symbol object (usually a Var or a Type)

Raises:

  • (DuplicationSymError) —

    if ‘name’ is already in the symbol table



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# File 'lib/idl/symbol_table.rb', line 318

def add!(name, var)
  raise DuplicateSymError, "Symbol #{name} already defined as #{get(name)}" unless @scopes.select { |h| h.key? name }.empty?

  @scopes.last[name] = var
end

#add_above!(name, var) ⇒ Object

add to the scope above the tail, and make sure name is unique at that scope



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# File 'lib/idl/symbol_table.rb', line 325

def add_above!(name, var)
  raise "There is only one scope" if @scopes.size <= 1

  raise "Symbol #{name} already defined" unless @scopes[0..-2].select { |h| h.key? name }.empty?

  @scopes[-2][name] = var
end

#add_at!(level, name, var) ⇒ Object

add to the scope at level, and make sure name is unique at that scope



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# File 'lib/idl/symbol_table.rb', line 334

def add_at!(level, name, var)
  raise "Level #{level} is too large #{@scopes.size}" if  level >= @scopes.size

  raise "Symbol #{name} already defined" unless @scopes[0...level].select { |h| h.key? name }.empty?

  @scopes[level][name] = var
end

#at_global_scope? ⇒ Boolean

Returns true if the symbol table is at the global scope.

Returns:

  • (Boolean) —

    true if the symbol table is at the global scope



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# File 'lib/idl/symbol_table.rb', line 357

def at_global_scope?
  @scopes.size == 1
end

#callstack ⇒ Object 



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# File 'lib/idl/symbol_table.rb', line 243

def callstack
  @callstack.reverse.map { |ast| ast.nil? ? "" : "#{ast.input_file}:#{ast.lineno}" }.join("\n")
end

#deep_clone(clone_values: false, freeze_global: true) ⇒ SymbolTable

Returns a deep clone of this SymbolTable.

Returns:



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# File 'lib/idl/symbol_table.rb', line 402

def deep_clone(clone_values: false, freeze_global: true)
  raise "don't do this" unless freeze_global

  # globals are frozen, so we can just return a shallow clone
  # if we are in global scope
  if levels == 1
    copy = dup
    copy.instance_variable_set(:@scopes, copy.instance_variable_get(:@scopes).dup)
    copy.instance_variable_set(:@callstack, copy.instance_variable_get(:@callstack).dup)
    return copy
  end

  copy = dup
  # back up the table to global scope
  copy.instance_variable_set(:@callstack, @callstack.dup)
  copy.instance_variable_set(:@scopes, [])
  c_scopes = copy.instance_variable_get(:@scopes)
  c_scopes.push(@scopes[0])

  @scopes[1..].each do |scope|
    c_scopes << {}
    scope.each do |k, v|
      if clone_values
        c_scopes.last[k] = v.dup
      else
        c_scopes.last[k] = v
      end
    end
  end
  copy
end

#deep_freeze ⇒ Object

do a deep freeze to protect the sym table and all its entries from modification



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# File 'lib/idl/symbol_table.rb', line 186

def deep_freeze
  @scopes.each do |k, v|
    k.freeze
    v.freeze
  end
  @scopes.freeze

  # set frozen_hash so that we can quickly compare symtabs
  @frozen_hash = [@scopes.hash, @archdef.hash].hash

  # set up the global clone that be used as a mutable table
  @global_clone_pool = []

  5.times do
    copy = SymbolTable.allocate
    copy.instance_variable_set(:@scopes, [@scopes[0]])
    copy.instance_variable_set(:@callstack, [@callstack[0]])
    copy.instance_variable_set(:@archdef, @archdef)
    copy.instance_variable_set(:@mxlen, @mxlen)
    copy.instance_variable_set(:@global_clone_pool, @global_clone_pool)
    copy.instance_variable_set(:@in_use, false)
    @global_clone_pool << copy
  end

  freeze
  self
end

#find_all(single_scope: false) {|obj| ... } ⇒ Array<Object>

searches the symbol table scope-by-scope to find all entries for which the block returns true

Parameters:

  • single_scope (Boolean) (defaults to: false) —

    If true, stop searching more scope as soon as there are matches

Yield Parameters:

  • obj (Object) —

    A object stored in the symbol table

Yield Returns:

  • (Boolean) —

    Whether or not the object is the one you are looking for

Returns:

  • (Array<Object>) —

    All matches

Raises:

  • (ArgumentError) 


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# File 'lib/idl/symbol_table.rb', line 289

def find_all(single_scope: false, &block)
  raise ArgumentError, "Block needed" unless block_given?

  raise ArgumentError, "Find block takes one argument" unless block.arity == 1

  matches = []

  @scopes.reverse_each do |s|
    s.each_value do |v|
      matches << v if yield v
    end
    break if single_scope && !matches.empty?
  end
  matches
end

#get(name) ⇒ Object

searches the symbol table scope-by-scope to find ‘name’

Returns:

  • (Object) —

    A symbol named ‘name’, or nil if not found



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# File 'lib/idl/symbol_table.rb', line 259

def get(name)
  @scopes.reverse_each do |s|
    result = s.fetch(name, nil)
    return result unless result.nil?
  end
  nil
end

#get_from(name, level) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/idl/symbol_table.rb', line 267

def get_from(name, level)
  raise ArgumentError, "level must be positive" unless level.positive?

  raise "There is no level #{level}" unless level < levels

  @scopes[0..level - 1].reverse_each do |s|
    return s[name] if s.key?(name)
  end
  nil
end

#get_global(name) ⇒ Object

Returns the symbol named ‘name’ from global scope, or nil if not found.

Returns:

  • (Object) —

    the symbol named ‘name’ from global scope, or nil if not found



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# File 'lib/idl/symbol_table.rb', line 279

def get_global(name)
  get_from(name, 1)
end

#global_clone ⇒ SymbolTable

Returns a mutable clone of the global scope of this SymbolTable.

Returns:

  • (SymbolTable) —

    a mutable clone of the global scope of this SymbolTable



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# File 'lib/idl/symbol_table.rb', line 362

def global_clone
  # raise "symtab isn't frozen" if @global_clone.nil?
  # raise "global clone isn't at global scope" unless @global_clone.at_global_scope?

  @global_clone_pool.each do |symtab|
    unless symtab.in_use?
      symtab.instance_variable_set(:@in_use, true)
      return symtab
    end
  end

  # need more!
  warn "Allocating more SymbolTables"
  5.times do
    copy = SymbolTable.allocate
    copy.instance_variable_set(:@scopes, [@scopes[0]])
    copy.instance_variable_set(:@callstack, [@callstack[0]])
    copy.instance_variable_set(:@archdef, @archdef)
    copy.instance_variable_set(:@mxlen, @mxlen)
    copy.instance_variable_set(:@global_clone_pool, @global_clone_pool)
    copy.instance_variable_set(:@in_use, false)
    @global_clone_pool << copy
  end

  global_clone
end

#hash ⇒ Object 



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# File 'lib/idl/symbol_table.rb', line 86

def hash
  return @frozen_hash unless @frozen_hash.nil?

  [@scopes.hash, @archdef.hash].hash
end

#in_use? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/idl/symbol_table.rb', line 399

def in_use? = @in_use

#inspect ⇒ String

Returns inspection string.

Returns:

  • (String) —

    inspection string



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# File 'lib/idl/symbol_table.rb', line 215

def inspect
  "SymbolTable[#{@archdef.name}]#{frozen? ? ' (frozen)' : ''}"
end

#key?(name) ⇒ Boolean

Returns whether or not any symbol ‘name’ is defined at any level in the symbol table.

Returns:

  • (Boolean) —

    whether or not any symbol ‘name’ is defined at any level in the symbol table



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# File 'lib/idl/symbol_table.rb', line 248

def key?(name)
  @scopes.each { |s| return true if s.key?(name) }
end

#keys_pretty ⇒ Object 



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# File 'lib/idl/symbol_table.rb', line 252

def keys_pretty
  @scopes.map { |s| s.map { |k, v| v.is_a?(Var) && v.template_val? ? "#{k} (template)" : k }}
end

#levels ⇒ Integer

Returns Number of scopes on the symbol table (global at 1).

Returns:

  • (Integer) —

    Number of scopes on the symbol table (global at 1)



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# File 'lib/idl/symbol_table.rb', line 343

def levels
  @scopes.size
end

#pop ⇒ Object

pops the top of the scope stack



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# File 'lib/idl/symbol_table.rb', line 233

def pop
  # puts "pop #{caller[0]}"
  # puts "    from #{@scope_caller.pop}"
  raise "Error: popping the symbol table would remove global scope" if @scopes.size == 1

  raise "?" unless @scopes.size == @callstack.size
  @scopes.pop
  @callstack.pop
end

#print ⇒ Object

pretty-print the symbol table contents



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# File 'lib/idl/symbol_table.rb', line 348

def print
  @scopes.each do |s|
    s.each do |name, obj|
      puts "#{name} #{obj}"
    end
  end
end

#push(ast) ⇒ SymbolTable

pushes a new scope

Returns:



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# File 'lib/idl/symbol_table.rb', line 221

def push(ast)
  # puts "push #{caller[0]}"
  # @scope_caller ||= []
  # @scope_caller.push caller[0]
  raise "#{@scopes.size} #{@callstack.size}" unless @scopes.size == @callstack.size
  @scopes << {}
  @callstack << ast
  @frozen_hash = nil
  self
end

#release ⇒ Object 



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# File 'lib/idl/symbol_table.rb', line 389

def release
  pop while levels > 1
  raise "Clone isn't back in global scope" unless at_global_scope?
  raise "You are calling release on the frozen SymbolTable" if frozen?
  raise "??" if @in_use.nil?
  raise "Double release detected" unless @in_use

  @in_use = false
end