Module: MilkTea::Layout

Defined in:
lib/milk_tea/core/types/layout.rb

Constant Summary collapse

POINTER_SIZE = 
Fiddle::SIZEOF_VOIDP

Class Method Summary collapse

Class Method Details

.align_up(value, alignment) ⇒ Object 



248
249
250
251
252
253
 
# File 'lib/milk_tea/core/types/layout.rb', line 248

def self.align_up(value, alignment)
  return value if alignment <= 1

  remainder = value % alignment
  remainder.zero? ? value : value + alignment - remainder
end

.alignment_of(type) ⇒ Object 



15
16
17
 
# File 'lib/milk_tea/core/types/layout.rb', line 15

def self.alignment_of(type)
  size_and_alignment(type, {})&.last
end

.array_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


217
218
219
 
# File 'lib/milk_tea/core/types/layout.rb', line 217

def self.array_type?(type)
  type.arguments.length == 2 && type.arguments[1].is_a?(Types::LiteralTypeArg) && type.arguments[1].value.is_a?(Integer)
end

.explicit_alignment(type) ⇒ Object 



213
214
215
 
# File 'lib/milk_tea/core/types/layout.rb', line 213

def self.explicit_alignment(type)
  type.respond_to?(:alignment) ? type.alignment : nil
end

.generic_layout(type, stack) ⇒ Object 



116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
 
# File 'lib/milk_tea/core/types/layout.rb', line 116

def self.generic_layout(type, stack)
  case type.name
  when "ptr", "const_ptr", "own", "ref"
    [POINTER_SIZE, POINTER_SIZE]
  when "array"
    return unless array_type?(type)

    element_layout = size_and_alignment(type.arguments.first, stack)
    return unless element_layout

    [element_layout.first * type.arguments[1].value, element_layout.last]
  when "str_buffer"
    return unless str_buffer_type?(type)

    with_stack(type, stack) do
      layout = struct_layout(str_buffer_fields(type), packed: false, alignment: nil, stack:)
      [layout[:size], layout[:alignment]]
    end
  end
end

.layout_pointer_like_nullable_base?(base) ⇒ Boolean

Returns:

  • (Boolean) 


234
235
236
237
238
239
 
# File 'lib/milk_tea/core/types/layout.rb', line 234

def self.layout_pointer_like_nullable_base?(base)
  return true if base.is_a?(Types::Function) || base.is_a?(Types::Proc) || base.is_a?(Types::Opaque)
  return true if base.is_a?(Types::Primitive) && base.name == "cstr"

  base.is_a?(Types::GenericInstance) && %w[ptr const_ptr own ref].include?(base.name)
end

.nullable_opt_layout_fields(base) ⇒ Object 



241
242
243
244
245
246
 
# File 'lib/milk_tea/core/types/layout.rb', line 241

def self.nullable_opt_layout_fields(base)
  {
    "has_value" => Types::Registry.primitive("bool"),
    "value" => base,
  }
end

.offset_of(type, field_name) ⇒ Object 



19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
 
# File 'lib/milk_tea/core/types/layout.rb', line 19

def self.offset_of(type, field_name)
  case type
  when Types::Struct, Types::StructInstance, Types::Span, Types::StringView, Types::Task
    fields = ordered_fields(type)
    return unless fields.key?(field_name)

    struct_layout(fields, packed: packed_layout?(type), alignment: explicit_alignment(type), stack: {})[:offsets][field_name]
  when Types::Union
    type.field(field_name) ? 0 : nil
  when Types::GenericInstance
    return unless str_buffer_type?(type)

    fields = str_buffer_fields(type)
    return unless fields.key?(field_name)

    struct_layout(fields, packed: false, alignment: nil, stack: {})[:offsets][field_name]
  else
    nil
  end
end

.ordered_fields(type) ⇒ Object 



205
206
207
 
# File 'lib/milk_tea/core/types/layout.rb', line 205

def self.ordered_fields(type)
  type.fields
end

.packed_layout?(type) ⇒ Boolean

Returns:

  • (Boolean) 


209
210
211
 
# File 'lib/milk_tea/core/types/layout.rb', line 209

def self.packed_layout?(type)
  type.respond_to?(:packed) && type.packed
end

.primitive_layout(type) ⇒ Object 



99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
 
# File 'lib/milk_tea/core/types/layout.rb', line 99

def self.primitive_layout(type)
  case type.name
  when "bool", "byte", "ubyte", "char"
    [1, 1]
  when "short", "ushort"
    [2, 2]
  when "int", "uint", "float"
    [4, 4]
  when "long", "ulong", "double"
    [8, 8]
  when "ptr_int", "ptr_uint", "cstr"
    [POINTER_SIZE, POINTER_SIZE]
  else
    nil
  end
end

.size_and_alignment(type, stack) ⇒ Object 



40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
 
# File 'lib/milk_tea/core/types/layout.rb', line 40

def self.size_and_alignment(type, stack)
  case type
  when Types::Primitive
    primitive_layout(type)
  when Types::EnumBase
    size_and_alignment(type.backing_type, stack)
  when Types::Nullable, Types::Function
    if type.is_a?(Types::Function) || layout_pointer_like_nullable_base?(type.base)
      [POINTER_SIZE, POINTER_SIZE]
    else
      with_stack(type, stack) do
        layout = struct_layout(nullable_opt_layout_fields(type.base), packed: false, alignment: nil, stack:)
        [layout[:size], layout[:alignment]]
      end
    end
  when Types::StringView, Types::Span, Types::Task, Types::Struct, Types::StructInstance
    with_stack(type, stack) do
      layout = struct_layout(ordered_fields(type), packed: packed_layout?(type), alignment: explicit_alignment(type), stack:)
      [layout[:size], layout[:alignment]]
    end
  when Types::Union
    with_stack(type, stack) do
      layout = union_layout(ordered_fields(type), packed: packed_layout?(type), alignment: explicit_alignment(type), stack:)
      [layout[:size], layout[:alignment]]
    end
  when Types::Variant, Types::VariantInstance
    with_stack(type, stack) do
      layout = variant_layout(type, stack:)
      [layout[:size], layout[:alignment]]
    end
  when Types::GenericInstance
    generic_layout(type, stack)
  when Types::Simd
    element_layout = size_and_alignment(type.element_type, stack)
    return unless element_layout

    total = element_layout.first * type.lane_count
    alignment = total > 16 ? 32 : 16
    [total, alignment]
  when Types::Vector
    element_layout = size_and_alignment(type.element_type, stack)
    return unless element_layout

    [element_layout.first * type.width, element_layout.last]
  when Types::Matrix
    element_layout = size_and_alignment(Types::BUILTIN_VECTOR_ELEMENT, stack)
    return unless element_layout

    [element_layout.first * type.dim * type.dim, element_layout.last]
  when Types::Quaternion
    element_layout = size_and_alignment(Types::BUILTIN_VECTOR_ELEMENT, stack)
    return unless element_layout

    [element_layout.first * 4, element_layout.last]
  else
    nil
  end
end

.size_of(type) ⇒ Object 



11
12
13
 
# File 'lib/milk_tea/core/types/layout.rb', line 11

def self.size_of(type)
  size_and_alignment(type, {})&.first
end

.str_buffer_fields(type) ⇒ Object 



225
226
227
228
229
230
231
232
 
# File 'lib/milk_tea/core/types/layout.rb', line 225

def self.str_buffer_fields(type)
  storage_capacity = type.arguments.first.value + 1
  {
    "data" => Types::Registry.generic_instance("array", [Types::Registry.primitive("char"), Types::LiteralTypeArg.new(storage_capacity)]),
    "len" => Types::Registry.primitive("ptr_uint"),
    "dirty" => Types::Registry.primitive("bool"),
  }
end

.str_buffer_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


221
222
223
 
# File 'lib/milk_tea/core/types/layout.rb', line 221

def self.str_buffer_type?(type)
  type.arguments.length == 1 && type.arguments.first.is_a?(Types::LiteralTypeArg) && type.arguments.first.value.is_a?(Integer)
end

.struct_layout(fields, packed:, alignment:, stack:) ⇒ Object 



151
152
153
154
155
156
157
158
159
160
 
# File 'lib/milk_tea/core/types/layout.rb', line 151

def self.struct_layout(fields, packed:, alignment:, stack:)
  field_infos = fields.map do |field_name, field_type|
    field_layout = size_and_alignment(field_type, stack)
    return nil unless field_layout

    [field_name, field_layout.first, field_layout.last]
  end

  struct_layout_from_infos(field_infos, packed:, alignment:)
end

.struct_layout_from_infos(field_infos, packed:, alignment:) ⇒ Object 



173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
 
# File 'lib/milk_tea/core/types/layout.rb', line 173

def self.struct_layout_from_infos(field_infos, packed:, alignment:)
  offsets = {}
  offset = 0
  natural_alignment = 1

  field_infos.each do |field_name, field_size, field_alignment|
    effective_alignment = packed ? 1 : field_alignment
    natural_alignment = [natural_alignment, effective_alignment].max
    offset = align_up(offset, effective_alignment) unless packed
    offsets[field_name] = offset
    offset += field_size
  end

  overall_alignment = [natural_alignment, alignment || 1].max
  {
    size: align_up(offset, overall_alignment),
    alignment: overall_alignment,
    offsets:,
  }
end

.union_layout(fields, packed:, alignment:, stack:) ⇒ Object 



162
163
164
165
166
167
168
169
170
171
 
# File 'lib/milk_tea/core/types/layout.rb', line 162

def self.union_layout(fields, packed:, alignment:, stack:)
  field_infos = fields.map do |_field_name, field_type|
    field_layout = size_and_alignment(field_type, stack)
    return nil unless field_layout

    field_layout
  end

  union_layout_from_layouts(field_infos.map { |size, field_alignment| { size:, alignment: field_alignment } }, packed:, alignment:)
end

.union_layout_from_layouts(layouts, packed:, alignment:) ⇒ Object 



194
195
196
197
198
199
200
201
202
203
 
# File 'lib/milk_tea/core/types/layout.rb', line 194

def self.union_layout_from_layouts(layouts, packed:, alignment:)
  natural_alignment = packed ? 1 : (layouts.map { |layout| layout[:alignment] }.max || 1)
  overall_alignment = [natural_alignment, alignment || 1].max
  size = layouts.map { |layout| layout[:size] }.max || 0

  {
    size: align_up(size, overall_alignment),
    alignment: overall_alignment,
  }
end

.variant_layout(type, stack:) ⇒ Object 



137
138
139
140
141
142
143
144
145
146
147
148
149
 
# File 'lib/milk_tea/core/types/layout.rb', line 137

def self.variant_layout(type, stack:)
  payload_layouts = type.arm_names.filter_map do |arm_name|
    fields = type.arm(arm_name)
    next if fields.nil? || fields.empty?

    struct_layout(fields, packed: false, alignment: nil, stack:)
  end

  data_layout = union_layout_from_layouts(payload_layouts, packed: false, alignment: nil)
  field_infos = [["kind", 4, 4]]
  field_infos << ["data", data_layout[:size], data_layout[:alignment]] if data_layout[:size].positive?
  struct_layout_from_infos(field_infos, packed: false, alignment: nil)
end

.with_stack(type, stack) ⇒ Object 



255
256
257
258
259
260
261
262
 
# File 'lib/milk_tea/core/types/layout.rb', line 255

def self.with_stack(type, stack)
  return if stack[type]

  stack[type] = true
  yield
ensure
  stack.delete(type)
end