Class: Idl::PostDecrementExpressionAst

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

Overview

represents a post-decrement expression

for example:

i--

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 Executable

#executable?

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, #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, rval) ⇒ PostDecrementExpressionAst

Returns a new instance of PostDecrementExpressionAst.



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# File 'lib/idlc/ast.rb', line 5660

def initialize(input, interval, rval)
  super(input, interval, [rval])
end

Class Method Details

.from_h(yaml, source_mapper) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 5703

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

  input = input_from_source_yaml(yaml.fetch("source"), source_mapper)
  interval = interval_from_source_yaml(yaml.fetch("source"))
  PostDecrementExpressionAst.new(
    input, interval,
    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 5655

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

#execute(symtab) ⇒ void

This method returns an undefined value.

"execute" the statement by updating the variables in the symbol table

Parameters:

  • symtab (SymbolTable) —

    The symbol table for the context

Raises:

  • ValueError if some part of the statement cannot be executed at compile time



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# File 'lib/idlc/ast.rb', line 5677

def execute(symtab)
  var = symtab.get(rval.text_value)
  value_result = value_try do
    internal_error "No symbol #{rval.text_value}" if var.nil?

    value_error "value of variable '#{rval.text_value}' not know" if var.value.nil?

    var.value = var.value - 1
  end
  value_else(value_result) do
    var.value = nil
    value_error "value of variable '#{rval.text_value}' not know"
  end
end

#gen_adoc(indent, indent_spaces: 2) ⇒ Object 



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# File 'lib/idlc/passes/gen_adoc.rb', line 55

def gen_adoc(indent, indent_spaces: 2)
  "#{' ' * indent}#{rval.gen_adoc(indent, indent_spaces:)}--"
end

#nullify_assignments(symtab) ⇒ Object 



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# File 'lib/idlc/passes/prune.rb', line 199

def nullify_assignments(symtab)
  var = symtab.get(rval.text_value)
  var.value = nil unless var.nil?
end

#prune(symtab, forced_type: nil) ⇒ Object 



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# File 'lib/idlc/passes/prune.rb', line 972

def prune(symtab, forced_type: nil)
  new_ast = PostDecrementExpressionAst.new(input, interval, rval.dup)
  value_try do
    new_ast.execute(symtab)
  end
  # value_else: execute already sets nil on failure, nothing more to do
  new_ast
end

#rval ⇒ Object 



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# File 'lib/idlc/ast.rb', line 5658

def rval = T.cast(@children.fetch(0), T.any(IntLiteralAst, BuiltinVariableAst, StringLiteralAst, IdAst))

#to_h ⇒ Object 



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# File 'lib/idlc/ast.rb', line 5696

def to_h = {
  "kind" => "post_decrement_expr",
  "expr" => rval.to_h,
  "source" => source_yaml
}

#to_idl ⇒ Object 



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# File 'lib/idlc/ast.rb', line 5693

def to_idl = "#{rval.to_idl}--"

#type(symtab) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 5672

def type(symtab)
  rval.type(symtab)
end

#type_check(symtab, strict:) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 5664

def type_check(symtab, strict:)
  rval.type_check(symtab, strict:)
  rval_immutable =
    rval.is_a?(IdAst) && (rval.type(symtab).const? && !symtab.get(T.cast(rval, IdAst).name).for_loop_iter?)
  type_error "Cannot decrement a const variable" if rval_immutable
  type_error "Post decement must be integral" unless rval.type(symtab).integral?
end