Class: Idl::ReturnExpressionAst

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

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 Returns

#expected_return_type

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, #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, return_nodes) ⇒ ReturnExpressionAst

Returns a new instance of ReturnExpressionAst.



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# File 'lib/idlc/ast.rb', line 6914

def initialize(input, interval, return_nodes)
  super(input, interval, return_nodes)
  @func_type_cache = {}
end

Class Method Details

.from_h(yaml, source_mapper) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6997

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

  input = input_from_source_yaml(yaml.fetch("source"), source_mapper)
  interval = interval_from_source_yaml(yaml.fetch("source"))
  ReturnExpressionAst.new(
    input, interval,
    yaml.fetch("exprs").map { |r| AstNode.from_h(r, source_mapper) }
  )
end

Instance Method Details

#const_eval?(symtab) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/idlc/ast.rb', line 6910

def const_eval?(symtab) = return_value_nodes.all? { |node| node.const_eval?(symtab) }

#enclosing_function ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6960

def enclosing_function
  find_ancestor(FunctionDefAst)
end

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



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# File 'lib/idlc/passes/gen_adoc.rb', line 35

def gen_adoc(indent = 0, indent_spaces: 2)
  "#{' ' * indent}return #{return_value_nodes.map { |r| r.gen_adoc(0, indent_spaces:) }.join(', ')}"
end

#gen_option_adoc ⇒ Object 



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# File 'lib/idlc/passes/gen_option_adoc.rb', line 115

def gen_option_adoc
  raise "unexpected" if return_value_nodes.size != 1

  return_value_nodes[0].gen_option_adoc
end

#prune(symtab, forced_type: nil) ⇒ Object 



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# File 'lib/idlc/passes/prune.rb', line 877

def prune(symtab, forced_type: nil)
  ReturnExpressionAst.new(input, interval, return_value_nodes.map { |n| n.prune(symtab) })
end

#return_type(symtab) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6933

def return_type(symtab)
  types = return_types(symtab)
  if types.empty?
    return Type.new(:void)
  elsif types.size > 1
    Type.new(:tuple, tuple_types: types)
  else
    types.fetch(0)
  end
end

#return_types(symtab) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6921

def return_types(symtab)
  if return_value_nodes.empty?
    [Type.new(:void)]
  elsif return_value_nodes[0].type(symtab).kind == :tuple
    return_value_nodes[0].type(symtab).tuple_types
  else
    return_value_nodes.map { |v| v.type(symtab) }
  end
end

#return_value(symtab) ⇒ Integer, ...

Evaluate the compile-time return value of this node, or, if the node does not return (e.g., because it is an IfAst but there is no return on the taken path), execute the node and update the symtab

Parameters:

  • symtab (SymbolTable) —

    The symbol table for the context

Returns:

  • (Integer) —

    The return value, if it is integral

  • (Boolean) —

    The return value, if it is boolean

  • (nil) —

    if the return value is not compile-time-known

Raises:

  • ValueError if, during evaluation, a node without a compile-time value is found



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# File 'lib/idlc/ast.rb', line 6965

def return_value(symtab)
  if return_value_nodes.empty?
    :void
  elsif return_value_nodes.size == 1
    return_value_nodes[0].value(symtab)
  else
    return_value_nodes.map { |v| v.value(symtab) }
  end
end

#return_value_nodes ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6912

def return_value_nodes = @children

#return_values(symtab) ⇒ Array<Integer>, Array<Boolean>

Evaluate all possible compile-time return values of this node, or, if the node does not return (e.g., because it is an IfAst but there is no return on a possible path), execute the node and update the symtab

Parameters:

  • symtab (SymbolTable) —

    The symbol table for the context

Returns:

  • (Array<Integer>) —

    The possible return values. Will be an empty array if there are no return values

  • (Array<Boolean>) —

    The possible return values. Will be an empty array if there are no return values

Raises:

  • ValueError if, during evaluation, a node without a compile-time value is found



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# File 'lib/idlc/ast.rb', line 6976

def return_values(symtab)
  if return_value_nodes.empty?
    [:void]
  elsif return_value_nodes.size == 1
    return_value_nodes[0].values(symtab)
  else
    return_value_nodes.map { |v| v.values(symtab) }
  end
end

#to_h ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6990

def to_h = {
  "kind" => "return_expr",
  "exprs" => return_value_nodes.map(&:to_h),
  "source" => source_yaml
}

#to_idl ⇒ Object 



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# File 'lib/idlc/ast.rb', line 6987

def to_idl = "return #{return_value_nodes.map(&:to_idl).join(',')}"

#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 6945

def type_check(symtab, strict:)
  return_value_nodes.each do |v|
    v.type_check(symtab, strict:)
    type_error "Unknown type for #{v.text_value}" if v.type(symtab).nil?
  end

  if !return_value_nodes.empty? && return_value_nodes[0].type(symtab).kind == :tuple
    type_error("Can't combine tuple types in return") unless return_value_nodes.size == 1
  end

  unless return_type(symtab).convertable_to?(expected_return_type(symtab))
    type_error "Return type (#{return_type(symtab)}) not convertible to expected return type (#{expected_return_type(symtab)})"
  end
end