Module: MilkTea::CBackend::AggregateUtils

Included in:
MilkTea::CBackend
Defined in:
lib/milk_tea/core/c_backend/aggregate_utils.rb

Instance Method Summary collapse

Instance Method Details

#aggregate_can_reach?(from, to, value_refs, visited = {}) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 100

def aggregate_can_reach?(from, to, value_refs, visited = {})
  return false if visited[from]
  return true if from == to
  return true if (value_refs[from] || Set.new).include?(to)

  visited[from] = true
  (value_refs[from] || Set.new).any? { |next_name| aggregate_can_reach?(next_name, to, value_refs, visited) }
end

#aggregate_decl_dependencies(aggregate_decl) ⇒ Object 



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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 53

def aggregate_decl_dependencies(aggregate_decl)
  own_name = aggregate_decl.linkage_name
  deps = case aggregate_decl
  when IR::StructDecl, IR::UnionDecl
    aggregate_decl.fields.flat_map { |field| aggregate_type_dependencies(field.type) }
  when IR::VariantDecl
    aggregate_decl.arms.flat_map { |arm| arm.fields.flat_map { |field| aggregate_type_dependencies(field.type) } }
  else
    []
  end

  deps.uniq.reject do |dep|
    next true if dep == own_name
    next false unless aggregate_decl.is_a?(IR::VariantDecl)

    (@cyclic_aggregate_pairs || Set.new).include?([own_name, dep])
  end
end

#aggregate_field_creates_cycle?(field_type, outer_c) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 109

def aggregate_field_creates_cycle?(field_type, outer_c)
  resolved = resolved_aggregate_c_name(field_type)
  return false unless resolved

  return true if resolved == outer_c
  return false unless @cyclic_aggregate_pairs

  @cyclic_aggregate_pairs.include?([outer_c, resolved])
end

#aggregate_type_dependencies(type) ⇒ Object 



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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 132

def aggregate_type_dependencies(type)
  case type
  when Types::Nullable
    if c_backend_pointer_like_type?(type.base)
      aggregate_type_dependencies(type.base)
    else
      [nullable_opt_type_name(type)]
    end
  when Types::Task
    [task_type_name(type)]
  when Types::Proc
    [proc_type_name(type)]
  when Types::GenericInstance
    if pointer_type?(type)
      []
    elsif array_type?(type)
      aggregate_type_dependencies(array_element_type(type))
    elsif str_buffer_type?(type)
      [str_buffer_type_name(type)]
    else
      []
    end
  when Types::Function
    []
  when Types::Struct, Types::StructInstance, Types::Union, Types::Variant, Types::VariantInstance, Types::Event, Types::Subscription
    [named_type_c_name(type)]
  when Types::VariantArmPayload
    [named_type_c_name(type), named_type_c_name(type.variant_type)]
  else
    []
  end
end

#build_cyclic_aggregate_pairs(all_decls) ⇒ Object 



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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 72

def build_cyclic_aggregate_pairs(all_decls)
  by_name = all_decls.each_with_object({}) { |d, h| h[d.linkage_name] = d }
  value_refs = {}
  all_decls.each { |d| value_refs[d.linkage_name] = Set.new }

  all_decls.each do |decl|
    own = decl.linkage_name
    fields = case decl
    when IR::StructDecl, IR::UnionDecl then decl.fields
    when IR::VariantDecl then decl.arms.flat_map(&:fields)
    else []
    end
    fields.each do |f|
      aggregate_type_dependencies(f.type).each do |dep|
        value_refs[own] << dep if by_name.key?(dep) && dep != own
      end
    end
  end

  pairs = Set.new
  value_refs.each do |a, refs|
    refs.each do |b|
      pairs << [a, b] if aggregate_can_reach?(b, a, value_refs)
    end
  end
  pairs
end

#each_variant_arm_field_type ⇒ Object 



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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 6

def each_variant_arm_field_type
  @program.variants.each do |variant_decl|
    variant_decl.arms.each do |arm|
      arm.fields.each do |field|
        yield field.type
      end
    end
  end
end

#resolved_aggregate_c_name(type) ⇒ Object 



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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 119

def resolved_aggregate_c_name(type)
  case type
  when Types::Variant, Types::VariantInstance, Types::Struct, Types::StructInstance, Types::Union
    named_type_c_name(type)
  when Types::Nullable
    resolved_aggregate_c_name(type.base)
  when Types::GenericInstance
    if array_type?(type) || str_buffer_type?(type)
      resolved_aggregate_c_name(array_element_type(type))
    end
  end
end

#sort_aggregate_decls(struct_decls, union_decls, variant_decls) ⇒ Object 



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# File 'lib/milk_tea/core/c_backend/aggregate_utils.rb', line 16

def sort_aggregate_decls(struct_decls, union_decls, variant_decls)
  aggregate_decls = struct_decls + union_decls + variant_decls
  by_c_name = aggregate_decls.each_with_object({}) do |aggregate_decl, declarations|
    declarations[aggregate_decl.linkage_name] = aggregate_decl
  end
  variant_decls.each do |variant_decl|
    variant_decl.arms.each do |arm|
      next if arm.fields.empty?
      by_c_name[arm.linkage_name] = variant_decl
    end
  end
  visiting = {}
  visited = {}
  sorted = []

  visit = lambda do |aggregate_decl|
    return if visited[aggregate_decl.linkage_name]
    raise CBackendError.new("cyclic aggregate dependency involving #{aggregate_decl.linkage_name}", line: 0, column: 0, path: @path) if visiting[aggregate_decl.linkage_name]

    visiting[aggregate_decl.linkage_name] = true
    aggregate_decl_dependencies(aggregate_decl).each do |dependency|
      next unless by_c_name.key?(dependency)

      visit.call(by_c_name.fetch(dependency))
    end
    visiting.delete(aggregate_decl.linkage_name)
    visited[aggregate_decl.linkage_name] = true
    sorted << aggregate_decl
  end

  aggregate_decls.each do |aggregate_decl|
    visit.call(aggregate_decl)
  end

  sorted
end