1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
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
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
use crate::compile::{CommonOptions, CompiledArtifact};
use spirv_cross_sys as sys;

/// An MSL `constexpr` inlined sampler.
pub use spirv_cross_sys::MslConstexprSampler as ConstexprSampler;

/// Sampler addressing mode for inlined samplers.
pub use spirv_cross_sys::MslSamplerAddress as SamplerAddress;
/// Sampler border color for inlined samplers.
pub use spirv_cross_sys::MslSamplerBorderColor as SamplerBorderColor;
/// Sampler compare function for inline samplers.
pub use spirv_cross_sys::MslSamplerCompareFunc as SamplerCompareFunc;
/// Whether texture coordinates are normalized or not for inline samplers.
pub use spirv_cross_sys::MslSamplerCoord as SamplerCoord;
/// Mag and min filter mode for inline samplers.
pub use spirv_cross_sys::MslSamplerFilter as SamplerFilter;
/// Mip filtering mode for inline samplers.
pub use spirv_cross_sys::MslSamplerMipFilter as SamplerMipFilter;

/// Y′CbCr chroma location.
pub use spirv_cross_sys::MslChromaLocation as YcbcrChromaLocation;
/// Y′CbCr conversion component swizzle.
pub use spirv_cross_sys::MslComponentSwizzle as YcbcrComponentSwizzle;
/// Y′CbCr conversion format resolution.
pub use spirv_cross_sys::MslFormatResolution as YcbcrFormatResolution;
/// Y′CbCr model conversion options for inline samplers.
pub use spirv_cross_sys::MslSamplerYcbcrConversion as SamplerYcbcrConversion;
/// Format to convert when converting Y′CbCr.
pub use spirv_cross_sys::MslSamplerYcbcrModelConversion as YcbcrTargetFormat;

/// Conversion range for Y′CbCr.
pub use spirv_cross_sys::MslSamplerYcbcrRange as YcbcrConversionRange;

/// Indicates the format of a shader interface variable. Currently limited to specifying
/// if the input is an 8-bit unsigned integer, 16-bit unsigned integer, or
/// some other format.
pub use spirv_cross_sys::MslShaderVariableFormat as ShaderVariableFormat;

/// Indicates the rate at which a variable changes value, one of: per-vertex,
/// per-primitive, or per-patch.
pub use spirv_cross_sys::MslShaderVariableRate as ShaderVariableRate;

/// Maximum number of argument buffers supported.
pub const MAX_ARGUMENT_BUFFERS: u32 = 8;

use crate::error::ToContextError;
use crate::handle::{Handle, VariableId};
use crate::sealed::Sealed;
use crate::string::CompilerStr;
use crate::targets::Msl;
use crate::{error, Compiler, ContextRooted};
use spirv_cross_sys::{MslResourceBinding2, MslShaderInterfaceVar2, SpvBuiltIn, SpvExecutionModel};
use std::fmt::{Debug, Formatter};
use std::num::NonZeroU32;

impl Sealed for CompilerOptions {}
/// MSL compiler options
#[non_exhaustive]
#[derive(Debug, spirv_cross2_derive::CompilerOptions)]
pub struct CompilerOptions {
    /// Compile options common to GLSL, HLSL, and MSL.
    #[expand]
    pub common: CommonOptions,

    /// The MSL version to compile to.
    ///
    /// Defaults to MSL 1.2.
    #[option(SPVC_COMPILER_OPTION_MSL_VERSION)]
    pub version: MslVersion,

    /// Width of 2D Metal textures used as 1D texel buffers.
    #[option(SPVC_COMPILER_OPTION_MSL_TEXEL_BUFFER_TEXTURE_WIDTH, 4096)]
    pub texel_buffer_texture_width: u32,

    /// Index of the swizzle buffer.
    ///
    /// The default is 30.
    #[option(SPVC_COMPILER_OPTION_MSL_SWIZZLE_BUFFER_INDEX, 30)]
    pub swizzle_buffer_index: u32,

    /// Index of the indirect params buffer.
    ///
    /// The default is 29.
    #[option(SPVC_COMPILER_OPTION_MSL_INDIRECT_PARAMS_BUFFER_INDEX, 29)]
    pub indirect_params_buffer_index: u32,

    /// Index of the shader output buffer.
    ///
    /// The default is 28.
    #[option(SPVC_COMPILER_OPTION_MSL_SHADER_OUTPUT_BUFFER_INDEX, 28)]
    pub shader_output_buffer_index: u32,

    /// Index of the shader patch output buffer.
    ///
    /// The default is 27.
    #[option(SPVC_COMPILER_OPTION_MSL_SHADER_PATCH_OUTPUT_BUFFER_INDEX, 27)]
    pub shader_patch_output_buffer_index: u32,

    /// Index of the shader tesselation factor output buffer.
    ///
    /// The default is 26.
    #[option(SPVC_COMPILER_OPTION_MSL_SHADER_TESS_FACTOR_OUTPUT_BUFFER_INDEX, 26)]
    pub shader_tess_factor_output_buffer_index: u32,

    /// Index of the buffer size buffer.
    ///
    /// The default is 25.
    #[option(SPVC_COMPILER_OPTION_MSL_BUFFER_SIZE_BUFFER_INDEX, 25)]
    pub buffer_size_buffer_index: u32,

    /// Index of the view mask buffer.
    ///
    /// The default is 24
    #[option(SPVC_COMPILER_OPTION_MSL_VIEW_MASK_BUFFER_INDEX, 24)]
    pub view_mask_buffer_index: u32,

    /// Index of the dynamic offsets buffer.
    ///
    /// The default is 23
    #[option(SPVC_COMPILER_OPTION_MSL_DYNAMIC_OFFSETS_BUFFER_INDEX, 23)]
    pub dynamic_offsets_buffer_index: u32,

    /// Index of the shader input buffer.
    ///
    /// The default is 22.
    #[option(SPVC_COMPILER_OPTION_MSL_SHADER_INPUT_BUFFER_INDEX, 22)]
    pub shader_input_buffer_index: u32,

    /// Index of the shader index buffer.
    ///
    /// The default is 21.
    #[option(SPVC_COMPILER_OPTION_MSL_SHADER_INDEX_BUFFER_INDEX, 21)]
    pub shader_index_buffer_index: u32,

    /// Index of the shader patch input buffer.
    ///
    /// The default is 20.
    #[option(SPVC_COMPILER_OPTION_MSL_SHADER_PATCH_INPUT_BUFFER_INDEX, 20)]
    pub shader_patch_input_buffer_index: u32,

    /// Index of the input workgroup index buffer.
    ///
    /// The default is 0
    #[option(SPVC_COMPILER_OPTION_MSL_SHADER_INPUT_WORKGROUP_INDEX, 0)]
    pub shader_input_workgroup_index: u32,

    /// Enable `point_size` builtin.
    #[option(SPVC_COMPILER_OPTION_MSL_ENABLE_POINT_SIZE_BUILTIN, true)]
    pub enable_point_size_builtin: bool,

    /// Enable the `FragDepth` builtin.
    ///
    /// Disable if pipeline does not enable depth, as pipeline
    /// creation might otherwise fail.
    #[option(SPVC_COMPILER_OPTION_MSL_ENABLE_FRAG_DEPTH_BUILTIN, true)]
    pub enable_frag_depth_builtin: bool,

    /// Enable the `FragStencilRef` output.
    ///
    /// Disablle if pipeline does not enable  stencil  output,
    /// as pipeline creation might otherwise fail.
    #[option(SPVC_COMPILER_OPTION_MSL_ENABLE_FRAG_STENCIL_REF_BUILTIN, true)]
    pub enable_frag_stencil_ref_builtin: bool,

    ///
    #[option(SPVC_COMPILER_OPTION_MSL_DISABLE_RASTERIZATION, false)]
    pub disable_rasterization: bool,

    /// Writes geometry varyings to a buffer instead of as stage-outputs.
    #[option(SPVC_COMPILER_OPTION_MSL_CAPTURE_OUTPUT_TO_BUFFER, false)]
    pub capture_output_to_buffer: bool,

    /// Works around lack of support for VkImageView component swizzles.
    /// Recent Metal versions do not require this workaround.
    /// This has a massive impact on performance and bloat.
    ///
    /// Do not use this unless you are absolutely forced to.
    ///
    /// To use this feature, the API side must pass down swizzle buffers.
    /// Should only be used by translation layers as a last resort.
    #[option(SPVC_COMPILER_OPTION_MSL_SWIZZLE_TEXTURE_SAMPLES, false)]
    pub swizzle_texture_samples: bool,

    /// Always emit color outputs as 4-component variables.
    ///
    /// In Metal, the fragment shader must emit at least as many components
    /// as the render target format.
    #[option(SPVC_COMPILER_OPTION_MSL_PAD_FRAGMENT_OUTPUT_COMPONENTS, false)]
    pub pad_fragment_output_components: bool,

    /// Use a lower-left tessellation domain.
    #[option(SPVC_COMPILER_OPTION_MSL_TESS_DOMAIN_ORIGIN_LOWER_LEFT, false)]
    pub tess_domain_origin_lower_left: bool,

    /// The plattform to output MSL for. Defaults to macOS.
    #[option(SPVC_COMPILER_OPTION_MSL_PLATFORM, MetalPlatform::MacOS)]
    pub platform: MetalPlatform,

    /// Enable use of Metal argument buffers.
    ///
    /// MSL 2.0 or higher must be used.
    #[option(SPVC_COMPILER_OPTION_MSL_ARGUMENT_BUFFERS, false)]
    pub argument_buffers: bool,

    /// Defines Metal argument buffer tier levels.
    /// Uses same values as Metal `MTLArgumentBuffersTier` enumeration.
    #[option(
        SPVC_COMPILER_OPTION_MSL_ARGUMENT_BUFFERS_TIER,
        ArgumentBuffersTier::Tier1
    )]
    pub argument_buffers_tier: ArgumentBuffersTier,

    /// Requires MSL 2.1, use the native support for texel buffers.
    #[option(SPVC_COMPILER_OPTION_MSL_TEXTURE_BUFFER_NATIVE, false)]
    pub texture_buffer_native: bool,

    /// Enable SPV_KHR_multiview emulation.
    #[option(SPVC_COMPILER_OPTION_MSL_MULTIVIEW, false)]
    pub multiview: bool,

    /// If disabled, don't set `[[render_target_array_index]]` in multiview shaders.
    ///
    /// Useful for devices which don't support layered rendering.
    ///
    /// Only effective when [`CompilerOptions::multiview`] is enabled.
    #[option(SPVC_COMPILER_OPTION_MSL_MULTIVIEW_LAYERED_RENDERING, true)]
    pub multiview_layered_rendering: bool,

    /// The index of the device
    #[option(SPVC_COMPILER_OPTION_MSL_DEVICE_INDEX, 0)]
    pub device_index: u32,

    /// Treat the view index as the device index instead. For multi-GPU rendering.
    #[option(SPVC_COMPILER_OPTION_MSL_VIEW_INDEX_FROM_DEVICE_INDEX, false)]
    pub view_index_from_device_index: bool,

    /// Add  support for `vkCmdDispatchBase()` or similar APIs.
    ///
    /// Offsets the workgroup ID based on a buffer.
    #[option(SPVC_COMPILER_OPTION_MSL_DISPATCH_BASE, false)]
    pub dispatch_base: bool,

    /// Emit Image variables of dimension Dim1D as `texture2d`.
    ///
    /// In Metal, 1D textures do not support all features that 2D textures do.
    ///
    /// Use this option if your code relies on these features.
    #[option(SPVC_COMPILER_OPTION_MSL_TEXTURE_1D_AS_2D, false)]
    pub texture_1d_as_2d: bool,

    /// Ensures vertex and instance indices start at zero.
    ///
    /// This reflects the behavior of HLSL with SV_VertexID and SV_InstanceID.
    #[option(SPVC_COMPILER_OPTION_MSL_ENABLE_BASE_INDEX_ZERO, false)]
    pub enable_base_index_zero: bool,

    /// Use Metal's native frame-buffer fetch API for subpass inputs.
    #[option(SPVC_COMPILER_OPTION_MSL_FRAMEBUFFER_FETCH_SUBPASS, false)]
    pub framebuffer_fetch_subpass: bool,

    /// Enables use of "fma" intrinsic for invariant float math
    #[option(SPVC_COMPILER_OPTION_MSL_INVARIANT_FP_MATH, false)]
    pub invariant_fp_math: bool,

    /// Emulate texturecube_array with texture2d_array for iOS where this type is not available
    #[option(SPVC_COMPILER_OPTION_MSL_EMULATE_CUBEMAP_ARRAY, false)]
    pub emulate_cubemap_array: bool,

    /// Allow user to enable decoration binding
    #[option(SPVC_COMPILER_OPTION_MSL_ENABLE_DECORATION_BINDING, false)]
    pub enable_decoration_binding: bool,

    /// Forces all resources which are part of an argument buffer to be considered active.
    ///
    /// This ensures ABI compatibility between shaders where some resources might be unused,
    /// and would otherwise declare a different ABI.
    #[option(SPVC_COMPILER_OPTION_MSL_FORCE_ACTIVE_ARGUMENT_BUFFER_RESOURCES, false)]
    pub force_active_argument_buffer_resources: bool,

    /// Forces the use of plain arrays, which works around certain driver bugs on certain versions
    /// of Intel Macbooks.
    ///
    /// See <https://github.com/KhronosGroup/SPIRV-Cross/issues/1210>.
    /// May reduce performance in scenarios where arrays are copied around as value-types.
    #[option(SPVC_COMPILER_OPTION_MSL_FORCE_NATIVE_ARRAYS, false)]
    pub force_native_arrays: bool,

    /// Only selectively enable fragment outputs.
    ///
    /// Useful if pipeline does not enable
    /// fragment output for certain locations, as pipeline creation might otherwise fail.
    #[option(SPVC_COMPILER_OPTION_MSL_ENABLE_FRAG_OUTPUT_MASK, 0xffffffff)]
    pub enable_frag_output_mask: u32,

    /// If a shader writes clip distance, also emit user varyings which
    /// can be read in subsequent stages.
    #[option(SPVC_COMPILER_OPTION_MSL_ENABLE_CLIP_DISTANCE_USER_VARYING, true)]
    pub enable_clip_distance_user_varying: bool,

    /// In a tessellation control shader, assume that more than one patch can be processed in a
    /// single workgroup. This requires changes to the way the InvocationId and PrimitiveId
    /// builtins are processed, but should result in more efficient usage of the GPU.
    #[option(SPVC_COMPILER_OPTION_MSL_MULTI_PATCH_WORKGROUP, false)]
    pub multi_patch_workgroup: bool,

    /// If set, a vertex shader will be compiled as part of a tessellation pipeline.
    /// It will be translated as a compute kernel, so it can use the global invocation ID
    /// to index the output buffer.
    #[option(SPVC_COMPILER_OPTION_MSL_VERTEX_FOR_TESSELLATION, false)]
    pub vertex_for_tessellation: bool,

    /// The type of index in the index buffer, if present. For a compute shader, Metal
    /// requires specifying the indexing at pipeline creation, rather than at draw time
    /// as with graphics pipelines. This means we must create three different pipelines,
    /// for no indexing, 16-bit indices, and 32-bit indices. Each requires different
    /// handling for the gl_VertexIndex builtin. We may as well, then, create three
    /// different shaders for these three scenarios.
    #[option(SPVC_COMPILER_OPTION_MSL_VERTEX_INDEX_TYPE, IndexType::None)]
    pub vertex_index_type: IndexType,

    /// Assume that SubpassData images have multiple layers. Layered input attachments
    /// are addressed relative to the Layer output from the vertex pipeline. This option
    /// has no effect with multiview, since all input attachments are assumed to be layered
    /// and will be addressed using the current ViewIndex.
    #[option(SPVC_COMPILER_OPTION_MSL_ARRAYED_SUBPASS_INPUT, false)]
    pub arrayed_subpass_input: bool,

    /// The required alignment of linear textures of format `MTLPixelFormatR32Uint`.
    ///
    /// This is used to align the row stride for atomic accesses to such images.
    #[option(SPVC_COMPILER_OPTION_MSL_R32UI_LINEAR_TEXTURE_ALIGNMENT, 4)]
    pub r32ui_linear_texture_alignment: u32,

    /// The function constant ID to use for the linear texture alignment.
    ///
    /// On MSL 1.2 or later, you can override the alignment by setting this function constant.
    #[option(SPVC_COMPILER_OPTION_MSL_R32UI_ALIGNMENT_CONSTANT_ID, 65535)]
    pub r32ui_alignment_constant_id: u32,

    /// Whether to use SIMD-group or quadgroup functions to implement group non-uniform
    /// operations. Some GPUs on iOS do not support the SIMD-group functions, only the
    /// quadgroup functions.
    #[option(SPVC_COMPILER_OPTION_MSL_IOS_USE_SIMDGROUP_FUNCTIONS, false)]
    pub ios_use_simdgroup_functions: bool,

    /// If set, the subgroup size will be assumed to be one, and subgroup-related
    /// builtins and operations will be emitted accordingly.
    ///
    /// This mode is intended to be used by MoltenVK on hardware/software configurations
    /// which do not provide sufficient support for subgroups.
    #[option(SPVC_COMPILER_OPTION_MSL_EMULATE_SUBGROUPS, false)]
    pub emulate_subgroups: bool,

    /// If nonzero, a fixed subgroup size to assume. Metal, similarly to VK_EXT_subgroup_size_control,
    /// allows the SIMD-group size (aka thread execution width) to vary depending on
    /// register usage and requirements.
    ///
    /// In certain circumstances--for example, a pipeline
    /// in MoltenVK without VK_PIPELINE_SHADER_STAGE_CREATE_ALLOW_VARYING_SUBGROUP_SIZE_BIT_EXT--
    /// this is undesirable. This fixes the value of the SubgroupSize builtin, instead of
    /// mapping it to the Metal builtin `[[thread_execution_width]]`. If the thread
    /// execution width is reduced, the extra invocations will appear to be inactive.
    ///
    /// If zero, the SubgroupSize will be allowed to vary, and the builtin will be mapped
    /// to the Metal `[[thread_execution_width]]` builtin.
    #[option(SPVC_COMPILER_OPTION_MSL_FIXED_SUBGROUP_SIZE, 0)]
    pub fixed_subgroup_size: u32,

    /// If set, a dummy `[[sample_id]]` input is added to a fragment shader if none is present.
    ///
    /// This will force the shader to run at sample rate, assuming Metal does not optimize
    /// the extra threads away.
    #[option(SPVC_COMPILER_OPTION_MSL_FORCE_SAMPLE_RATE_SHADING, false)]
    pub force_sample_rate_shading: bool,

    /// Specifies whether the iOS target version supports the `[[base_vertex]]`
    /// and `[[base_instance]]` attributes.
    #[option(SPVC_COMPILER_OPTION_MSL_IOS_SUPPORT_BASE_VERTEX_INSTANCE, false)]
    pub ios_support_base_vertex_instance: bool,

    /// Use storage buffers instead of vertex-style attributes for tessellation evaluation
    /// input.
    ///
    /// This may require conversion of inputs in the generated post-tessellation
    /// vertex shader, but allows the use of nested arrays.
    #[option(SPVC_COMPILER_OPTION_MSL_RAW_BUFFER_TESE_INPUT, false)]
    pub raw_buffer_tese_input: bool,

    /// If set, gl_HelperInvocation will be set manually whenever a fragment is discarded.
    /// Some Metal devices have a bug where `simd_is_helper_thread()` does not return true
    /// after a fragment has been discarded.
    ///
    /// This is a workaround that is only expected to be needed
    /// until the bug is fixed in Metal; it is provided as an option to allow disabling it when that occurs.
    #[option(SPVC_COMPILER_OPTION_MSL_MANUAL_HELPER_INVOCATION_UPDATES, true)]
    pub manual_helper_invocation_updates: bool,

    /// If set, extra checks will be emitted in fragment shaders to prevent writes
    /// from discarded fragments. Some Metal devices have a bug where writes to storage resources
    /// from discarded fragment threads continue to occur, despite the fragment being
    /// discarded.
    ///
    /// This is a workaround that is only expected to be needed until the
    /// bug is fixed in Metal; it is provided as an option so it can be enabled
    /// only when the bug is present.
    #[option(SPVC_COMPILER_OPTION_MSL_CHECK_DISCARDED_FRAG_STORES, false)]
    pub check_discarded_frag_stores: bool,

    /// If set, Lod operands to OpImageSample*DrefExplicitLod for 1D and 2D array images
    /// will be implemented using a gradient instead of passing the level operand directly.
    ///
    /// Some Metal devices have a bug where the `level()` argument to `depth2d_array<T>::sample_compare()`
    /// in a fragment shader is biased by some unknown amount, possibly dependent on the
    /// partial derivatives of the texture coordinates.
    ///
    /// This is a workaround that is only
    /// expected to be needed until the bug is fixed in Metal; it is provided as an option
    /// so it can be enabled only when the bug is present.
    #[option(SPVC_COMPILER_OPTION_MSL_SAMPLE_DREF_LOD_ARRAY_AS_GRAD, false)]
    pub sample_dref_lod_array_as_grad: bool,

    /// MSL doesn't guarantee coherence between writes and subsequent reads of read_write textures.
    /// This inserts fences before each read of a read_write texture to ensure coherency.
    /// If you're sure you never rely on this, you can set this to false for a possible performance improvement.
    /// Note: Only Apple's GPU compiler takes advantage of the lack of coherency, so make sure to test on Apple GPUs if you disable this.
    #[option(SPVC_COMPILER_OPTION_MSL_READWRITE_TEXTURE_FENCES, true)]
    pub readwrite_texture_fences: bool,

    /// Metal 3.1 introduced a Metal regression bug which causes infinite recursion during
    /// Metal's analysis of an entry point input structure that is itself recursive. Enabling
    /// this option will replace the recursive input declaration with a alternate variable of
    /// type void*, and then cast to the correct type at the top of the entry point function.
    /// The bug has been reported to Apple, and will hopefully be fixed in future releases.
    #[option(SPVC_COMPILER_OPTION_MSL_REPLACE_RECURSIVE_INPUTS, false)]
    pub replace_recursive_inputs: bool,

    /// If set, manual fixups of gradient vectors for cube texture lookups will be performed.
    /// All released Apple Silicon GPUs to date behave incorrectly when sampling a cube texture
    /// with explicit gradients. They will ignore one of the three partial derivatives based
    /// on the selected major axis, and expect the remaining derivatives to be partially
    /// transformed.
    #[option(SPVC_COMPILER_OPTION_MSL_AGX_MANUAL_CUBE_GRAD_FIXUP, false)]
    pub agx_manual_cube_grad_fixup: bool,

    /// Metal will discard fragments with side effects under certain circumstances prematurely.
    /// Example: CTS test dEQP-VK.fragment_operations.early_fragment.discard_no_early_fragment_tests_depth
    /// Test will render a full screen quad with varying depth `[0,1]` for each fragment.
    /// Each fragment will do an operation with side effects, modify the depth value and
    /// discard the fragment. The test expects the fragment to be run due to:
    /// <https://registry.khronos.org/vulkan/specs/1.0-extensions/html/vkspec.html#fragops-shader-depthreplacement>
    /// which states that the fragment shader must be run due to replacing the depth in shader.
    ///
    /// However, Metal may prematurely discards fragments without executing them
    /// (I believe this to be due to a greedy optimization on their end) making the test fail.
    ///
    /// This option enforces fragment execution for such cases where the fragment has operations
    /// with side effects. Provided as an option hoping Metal will fix this issue in the future.
    #[option(
        SPVC_COMPILER_OPTION_MSL_FORCE_FRAGMENT_WITH_SIDE_EFFECTS_EXECUTION,
        false
    )]
    pub force_fragment_with_side_effects_execution: bool,
}

/// The version of Metal Shading Language to compile to.
///
/// Defaults to MSL 1.2.
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct MslVersion {
    /// The major version of MSL.
    pub major: u32,
    /// The minor version of MSL.
    pub minor: u32,
    /// The patch version of MSL.
    pub patch: u32,
}

impl MslVersion {
    /// Create a new `MslVersion`.
    pub const fn new(major: u32, minor: u32, patch: u32) -> Self {
        Self {
            major,
            minor,
            patch,
        }
    }
}

impl Default for MslVersion {
    fn default() -> Self {
        MslVersion::from((1, 2))
    }
}

impl Debug for MslVersion {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "MslVersion({}.{}.{})",
            self.major, self.minor, self.patch
        )
    }
}

impl From<MslVersion> for u32 {
    fn from(value: MslVersion) -> Self {
        (value.major * 10000) + (value.minor * 100) + value.patch
    }
}

impl From<(u32, u32)> for MslVersion {
    fn from(value: (u32, u32)) -> Self {
        Self {
            major: value.0,
            minor: value.1,
            patch: 0,
        }
    }
}

impl From<(u32, u32, u32)> for MslVersion {
    fn from(value: (u32, u32, u32)) -> Self {
        Self {
            major: value.0,
            minor: value.1,
            patch: value.2,
        }
    }
}

/// When using Metal argument buffers, indicates the Metal argument buffer tier level supported by the Metal platform.
///
/// Tier capabilities based on recommendations from Apple engineering.
#[repr(u32)]
#[derive(Debug, Copy, Clone)]
pub enum ArgumentBuffersTier {
    /// Tier1 supports writable images on macOS, but not on iOS.
    Tier1 = 0,
    /// Tier2 supports writable images on macOS and iOS, and higher resource count limits.
    Tier2 = 1,
}

/// The platform that the Metal runtime will be on.
#[repr(u32)]
#[derive(Debug, Copy, Clone)]
pub enum MetalPlatform {
    #[allow(non_camel_case_types)]
    /// iOS (mobile and iPad)
    iOS = 0,
    /// macOS (Desktop)
    MacOS = 1,
}

/// The type of index in the index buffer.
#[repr(u32)]
#[derive(Debug, Copy, Clone)]
pub enum IndexType {
    /// No index
    None = 0,
    /// Uint16 indices.
    Uint16 = 1,
    /// Uint32 indices.
    Uint32 = 2,
}

impl From<MetalPlatform> for u32 {
    fn from(value: MetalPlatform) -> Self {
        match value {
            MetalPlatform::iOS => 0,
            MetalPlatform::MacOS => 1,
        }
    }
}

impl From<IndexType> for u32 {
    fn from(value: IndexType) -> Self {
        match value {
            IndexType::None => 0,
            IndexType::Uint16 => 1,
            IndexType::Uint32 => 1,
        }
    }
}

impl From<ArgumentBuffersTier> for u32 {
    fn from(value: ArgumentBuffersTier) -> Self {
        match value {
            ArgumentBuffersTier::Tier1 => 0,
            ArgumentBuffersTier::Tier2 => 1,
        }
    }
}

/// Buffers that need to be provided to the MSL shader.
#[non_exhaustive]
#[derive(Debug, Clone)]
pub struct BufferRequirements {
    /// Whether an auxiliary swizzle buffer is needed by the shader.
    pub needs_swizzle_buffer: bool,
    /// Whether a buffer containing `STORAGE_BUFFER` buffer sizes to support OpArrayLength
    /// is needed by the shader.
    pub needs_buffer_size_buffer: bool,
    /// Whether an output buffer is needed by the shader.
    pub needs_output_buffer: bool,
    /// Whether a patch output buffer is needed by the shader.
    pub needs_patch_output_buffer: bool,
    /// Whether an input threadgroup buffer is needed by the shader.
    pub needs_input_threadgroup_buffer: bool,
}

/// Pipeline binding information for a resource.
///
/// Used to map a SPIR-V resource to an MSL buffer.
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum ResourceBinding {
    /// A resource with a qualified layout.
    ///
    /// i.e. `layout(set = 0, binding = 1)` in GLSL.
    Qualified {
        /// The descriptor set of the qualified layout.
        set: u32,
        /// The binding number of the qualified layout.
        binding: u32,
    },
    /// The push constant buffer.
    PushConstantBuffer,
    /// The swizzle buffer, at the given index.
    SwizzleBuffer(u32),
    /// The buffer binding for buffer size
    /// buffers to support `OpArrayLength`.
    BufferSizeBuffer(u32),
    /// The argument buffer, at the given index.
    ///
    /// This buffer binding should be kept as small as possible as all automatic bindings for buffers
    /// will start at `max(ResourceBinding::ArgumentBuffer) + 1`.
    ArgumentBuffer(u32),
}

impl ResourceBinding {
    /// Create a resource binding for a qualified SPIR-V layout
    /// specifier.
    pub const fn from_qualified(set: u32, binding: u32) -> Self {
        ResourceBinding::Qualified { set, binding }
    }

    const fn descriptor_set(&self) -> u32 {
        const PUSH_CONSTANT_DESCRIPTOR_SET: u32 = !0;
        match self {
            ResourceBinding::Qualified { set, .. }
            | ResourceBinding::SwizzleBuffer(set)
            | ResourceBinding::BufferSizeBuffer(set)
            | ResourceBinding::ArgumentBuffer(set) => *set,
            ResourceBinding::PushConstantBuffer => PUSH_CONSTANT_DESCRIPTOR_SET,
        }
    }

    const fn binding(&self) -> u32 {
        const PUSH_CONSTANT_BINDING: u32 = 0;
        const SWIZZLE_BUFFER_BINDING: u32 = !1;
        const BUFFER_SIZE_BUFFER_BINDING: u32 = !2;
        const ARGUMENT_BUFFER_BINDING: u32 = !3;

        match self {
            ResourceBinding::Qualified { binding, .. } => *binding,
            ResourceBinding::PushConstantBuffer => PUSH_CONSTANT_BINDING,
            ResourceBinding::SwizzleBuffer(_) => SWIZZLE_BUFFER_BINDING,
            ResourceBinding::BufferSizeBuffer(_) => BUFFER_SIZE_BUFFER_BINDING,
            ResourceBinding::ArgumentBuffer(_) => ARGUMENT_BUFFER_BINDING,
        }
    }
}

/// The MSL target to bind a resource to.
///
/// A single SPIR-V binding may bind to multiple
/// registers for multiple resource types.
///
/// The count field indicates the number of resources consumed by this binding, if the binding
/// represents an array of resources.
///
/// If the resource array is a run-time-sized array, which are legal in GLSL or SPIR-V, this value
/// will be used to declare the array size in MSL, which does not support run-time-sized arrays.
///
/// If using MSL 2.0 argument buffers (for iOS only) the resource is not a storage image,
/// the binding reference we remap to will become an `[[id(N)]]` attribute within
/// the argument buffer index specified in
/// [`ResourceBinding::ArgumentBuffer`].
///
/// For resources which are bound in the "classic" MSL 1.0 way or discrete descriptors, the remap will
/// become a `[[buffer(N)]]`, `[[texture(N)]]` or `[[sampler(N)]]` depending on the resource types used.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct BindTarget {
    /// The buffer index to bind to, if applicable.
    pub buffer: u32,
    /// The texture index to bind to, if applicable.
    pub texture: u32,
    /// The sampler index to bind to, if applicable.
    pub sampler: u32,
    /// The number of resources consumed by this binding,
    /// if the binding is an array of resources.
    pub count: Option<NonZeroU32>,
}

/// Defines MSL characteristics of a shader interface variable.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct ShaderInterfaceVariable {
    /// The builtin for the variable, if any.
    pub builtin: Option<spirv::BuiltIn>,
    /// The `vecsize` for this variable, if applicable.
    ///
    /// If `vecsize` is Some, it must be greater than or equal to the `vecsize` declared in the shader,
    /// or behavior in the generated shader is undefined.
    pub vecsize: Option<NonZeroU32>,
    /// The format of a shader interface variable.
    pub format: ShaderVariableFormat,
    /// Indicates the rate at which a variable changes value.
    pub rate: ShaderVariableRate,
}

impl ShaderInterfaceVariable {
    /// We need to be maybeuninit, because None builtin is represented by i32::MAX,
    /// which is invalid in Rust. I don't want to expose it just for this, so we'll just
    /// do some magic.
    #[must_use]
    fn to_raw(&self, location: u32) -> MslShaderInterfaceVar2 {
        let mut base = MslShaderInterfaceVar2 {
            location,
            format: self.format,
            builtin: SpvBuiltIn::Position,
            vecsize: self.vecsize.map_or(0, NonZeroU32::get),
            rate: self.rate,
        };

        if let Some(builtin) = self.builtin {
            // happy path, we can just set the builtin.
            base.builtin = SpvBuiltIn(builtin as u32 as i32);
        } else {
            base.builtin = SpvBuiltIn(i32::MAX);
        }

        base
    }
}

/// MSL specific APIs.
impl Compiler<Msl> {
    /// Get whether the vertex shader requires rasterization to be disabled.
    pub fn is_rasterization_disabled(&self) -> bool {
        unsafe { sys::spvc_compiler_msl_is_rasterization_disabled(self.ptr.as_ptr()) }
    }

    /// Get information such as required buffers for the MSL shader
    pub fn buffer_requirements(&self) -> BufferRequirements {
        unsafe {
            let needs_swizzle_buffer =
                sys::spvc_compiler_msl_needs_swizzle_buffer(self.ptr.as_ptr());
            let needs_buffer_size_buffer =
                sys::spvc_compiler_msl_needs_buffer_size_buffer(self.ptr.as_ptr());
            let needs_output_buffer = sys::spvc_compiler_msl_needs_output_buffer(self.ptr.as_ptr());
            let needs_patch_output_buffer =
                sys::spvc_compiler_msl_needs_patch_output_buffer(self.ptr.as_ptr());
            let needs_input_threadgroup_buffer =
                sys::spvc_compiler_msl_needs_input_threadgroup_mem(self.ptr.as_ptr());

            BufferRequirements {
                needs_swizzle_buffer,
                needs_buffer_size_buffer,
                needs_output_buffer,
                needs_patch_output_buffer,
                needs_input_threadgroup_buffer,
            }
        }
    }

    /// Add a shader interface variable description used to fix up shader input variables.
    ///
    /// If shader inputs are provided, [`CompiledArtifact::is_shader_input_used`] will return true after
    /// calling [`Compiler::compile`] if the location were used by the MSL code.
    ///
    /// Note: this covers the functionality implemented by the SPIR-V Cross
    /// C API `spvc_compiler_msl_add_vertex_attribute`.
    pub fn add_shader_input(
        &mut self,
        location: u32,
        variable: &ShaderInterfaceVariable,
    ) -> error::Result<()> {
        let variable = variable.to_raw(location);
        unsafe {
            sys::spvc_compiler_msl_add_shader_input_2(self.ptr.as_ptr(), &variable).ok(&*self)
        }
    }

    /// Add a shader interface variable description used to fix up shader output variables.
    ///
    /// If shader outputs are provided, [`CompiledArtifact::is_shader_input_used`] will return true after
    /// calling [`Compiler::compile`] if the location were used by the MSL code.
    ///
    /// Note: this covers the functionality implemented by the SPIR-V Cross
    /// C API `spvc_compiler_msl_add_vertex_attribute`.
    pub fn add_shader_output(
        &mut self,
        location: u32,
        variable: &ShaderInterfaceVariable,
    ) -> error::Result<()> {
        let variable = variable.to_raw(location);
        unsafe {
            sys::spvc_compiler_msl_add_shader_output_2(self.ptr.as_ptr(), &variable).ok(&*self)
        }
    }

    /// Add a resource binding to indicate the MSL buffer, texture or sampler index to use for a
    /// particular resource.
    ///
    /// If resource bindings are provided,
    /// [`CompiledArtifact<Msl>::is_resource_used`] will return true after [`Compiler::compile`] if
    /// the set/binding combination was used by the MSL code.
    pub fn add_resource_binding(
        &mut self,
        stage: spirv::ExecutionModel,
        binding: ResourceBinding,
        bind_target: &BindTarget,
    ) -> error::Result<()> {
        let binding = MslResourceBinding2 {
            stage: SpvExecutionModel(stage as u32 as i32),
            desc_set: binding.descriptor_set(),
            binding: binding.binding(),
            count: bind_target.count.map_or(0, NonZeroU32::get),
            msl_buffer: bind_target.buffer,
            msl_texture: bind_target.texture,
            msl_sampler: bind_target.sampler,
        };
        unsafe {
            sys::spvc_compiler_msl_add_resource_binding_2(self.ptr.as_ptr(), &binding).ok(&*self)
        }
    }

    /// When using MSL argument buffers, we can force "classic" MSL 1.0 binding schemes for certain descriptor sets.
    /// This corresponds to VK_KHR_push_descriptor in Vulkan.
    pub fn add_discrete_descriptor_set(&mut self, desc_set: u32) -> error::Result<()> {
        unsafe {
            sys::spvc_compiler_msl_add_discrete_descriptor_set(self.ptr.as_ptr(), desc_set)
                .ok(&*self)
        }
    }

    /// This function marks a resource as using a dynamic offset
    /// (`VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC` or `VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC`).
    ///
    /// `desc_set` and `binding` are the SPIR-V descriptor set and binding of a buffer resource
    /// in this shader.
    ///
    /// `index` is the index within the dynamic offset buffer to use.
    ///
    /// This function only has any effect if argument buffers are enabled.
    /// If so, the buffer will have its address adjusted at the beginning of the shader with
    /// an offset taken from the dynamic offset buffer.
    pub fn add_dynamic_buffer(
        &mut self,
        desc_set: u32,
        binding: u32,
        index: u32,
    ) -> error::Result<()> {
        unsafe {
            sys::spvc_compiler_msl_add_dynamic_buffer(self.ptr.as_ptr(), desc_set, binding, index)
                .ok(&*self)
        }
    }

    /// This function marks a resource an inline uniform block
    /// (`VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK_EXT`)
    ///
    /// `desc_set` and `binding` are the SPIR-V descriptor set and binding of a buffer resource
    /// in this shader.
    ///
    /// This function only has any effect if argument buffers are enabled.
    /// If so, the buffer block will be directly embedded into the argument
    /// buffer, instead of being referenced indirectly via pointer.
    pub fn add_inline_uniform_block(&mut self, desc_set: u32, binding: u32) -> error::Result<()> {
        unsafe {
            sys::spvc_compiler_msl_add_inline_uniform_block(self.ptr.as_ptr(), desc_set, binding)
                .ok(&*self)
        }
    }

    /// If an argument buffer is large enough, it may need to be in the device storage space rather than
    /// constant. Opt-in to this behavior here on a per-set basis.
    pub fn set_argument_buffer_device_address_space(
        &mut self,
        desc_set: u32,
        device_address: bool,
    ) -> error::Result<()> {
        unsafe {
            sys::spvc_compiler_msl_set_argument_buffer_device_address_space(
                self.ptr.as_ptr(),
                desc_set,
                device_address,
            )
            .ok(&*self)
        }
    }

    /// Remap a sampler with ID to a constexpr sampler.
    /// Older iOS targets must use constexpr samplers in certain cases (PCF),
    /// so a static sampler must be used.
    ///
    /// The sampler will not consume a binding, but be declared in the entry point as a constexpr sampler.
    /// This can be used on both combined image/samplers (sampler2D) or standalone samplers.
    /// The remapped sampler must not be an array of samplers.
    ///
    /// Prefer [`Compiler<Msl>::remap_constexpr_sampler_by_binding`] unless you're also doing reflection anyways.
    pub fn remap_constexpr_sampler(
        &mut self,
        variable: impl Into<Handle<VariableId>>,
        sampler: &ConstexprSampler,
        ycbcr: Option<&SamplerYcbcrConversion>,
    ) -> error::Result<()> {
        let variable = variable.into();
        let id = self.yield_id(variable)?;
        if let Some(ycbcr) = ycbcr {
            unsafe {
                sys::spvc_compiler_msl_remap_constexpr_sampler_ycbcr(
                    self.ptr.as_ptr(),
                    id,
                    sampler,
                    ycbcr,
                )
                .ok(&*self)
            }
        } else {
            unsafe {
                sys::spvc_compiler_msl_remap_constexpr_sampler(self.ptr.as_ptr(), id, sampler)
                    .ok(&*self)
            }
        }
    }

    /// Remap a sampler with set/binding, to a constexpr sampler.
    /// Older iOS targets must use constexpr samplers in certain cases (PCF),
    /// so a static sampler must be used.
    ///
    /// The sampler will not consume a binding, but be declared in the entry point as a constexpr sampler.
    /// This can be used on both combined image/samplers (sampler2D) or standalone samplers.
    /// The remapped sampler must not be an array of samplers.
    ///
    /// Remaps based on ID take priority over set/binding remaps.
    pub fn remap_constexpr_sampler_by_binding(
        &mut self,
        desc_set: u32,
        binding: u32,
        sampler: &ConstexprSampler,
        ycbcr: Option<&SamplerYcbcrConversion>,
    ) -> error::Result<()> {
        if let Some(ycbcr) = ycbcr {
            unsafe {
                sys::spvc_compiler_msl_remap_constexpr_sampler_by_binding_ycbcr(
                    self.ptr.as_ptr(),
                    desc_set,
                    binding,
                    sampler,
                    ycbcr,
                )
                .ok(&*self)
            }
        } else {
            unsafe {
                sys::spvc_compiler_msl_remap_constexpr_sampler_by_binding(
                    self.ptr.as_ptr(),
                    desc_set,
                    binding,
                    sampler,
                )
                .ok(&*self)
            }
        }
    }

    /// If using [`CompilerOptions::pad_fragment_output_components`], override the number of components we expect
    /// to use for a particular location. The default is 4 if number of components is not overridden.
    pub fn set_fragment_output_components(
        &mut self,
        location: u32,
        components: u32,
    ) -> error::Result<()> {
        unsafe {
            sys::spvc_compiler_msl_set_fragment_output_components(
                self.ptr.as_ptr(),
                location,
                components,
            )
            .ok(&*self)
        }
    }

    /// Set the suffix for combined image samplers.
    pub fn set_combined_sampler_suffix<'str>(
        &mut self,
        str: impl Into<CompilerStr<'str>>,
    ) -> error::Result<()> {
        unsafe {
            let str = str.into();

            let suffix = str.into_cstring_ptr()?;

            sys::spvc_compiler_msl_set_combined_sampler_suffix(self.ptr.as_ptr(), suffix.as_ptr())
                .ok(&*self)
        }
    }

    /// Get the suffix for combined image samplers.
    pub fn combined_sampler_suffix(&self) -> CompilerStr {
        unsafe {
            let suffix = sys::spvc_compiler_msl_get_combined_sampler_suffix(self.ptr.as_ptr());
            CompilerStr::from_ptr(suffix, self.ctx.drop_guard())
        }
    }

    /// Mask a stage output by location.
    ///
    /// If a shader output is active in this stage, but inactive in a subsequent stage,
    /// this can be signalled here. This can be used to work around certain cross-stage matching problems
    /// which plagues MSL in certain scenarios.
    ///
    /// An output which matches one of these will not be emitted in stage output interfaces, but rather treated as a private
    /// variable.
    ///
    /// This option is only meaningful for MSL and HLSL, since GLSL matches by location directly.
    ///
    pub fn mask_stage_output_by_location(
        &mut self,
        location: u32,
        component: u32,
    ) -> crate::error::Result<()> {
        unsafe {
            sys::spvc_compiler_mask_stage_output_by_location(self.ptr.as_ptr(), location, component)
                .ok(&*self)
        }
    }

    /// Mask a stage output by builtin. Masking builtins only takes effect if the builtin in question is part of the stage output interface.
    ///
    /// If a shader output is active in this stage, but inactive in a subsequent stage,
    /// this can be signalled here. This can be used to work around certain cross-stage matching problems
    /// which plagues MSL in certain scenarios.
    ///
    /// An output which matches one of these will not be emitted in stage output interfaces, but rather treated as a private
    /// variable.
    ///
    /// This option is only meaningful for MSL and HLSL, since GLSL matches by location directly.
    /// Masking builtins only takes effect if the builtin in question is part of the stage output interface.
    pub fn mask_stage_output_by_builtin(
        &mut self,
        builtin: spirv::BuiltIn,
    ) -> crate::error::Result<()> {
        unsafe {
            sys::spvc_compiler_mask_stage_output_by_builtin(
                self.ptr.as_ptr(),
                SpvBuiltIn(builtin as u32 as i32),
            )
            .ok(&*self)
        }
    }
}

#[derive(Copy, Clone, Debug, Default)]
#[non_exhaustive]
/// The tier of automatic resource binding.
///
/// Note that tertiary and quaternary bindings are not accessible via
/// the SPIR-V Cross C API.
pub enum AutomaticResourceBindingTier {
    #[default]
    /// The primary automatic resource binding.
    Primary,

    /// Should only be used for combined image samplers, in which case the
    /// sampler's binding is returned instead.
    ///
    /// Also used for the auxillary image atomic buffer.
    Secondary,
}

impl CompiledArtifact<Msl> {
    /// Returns whether the set/binding combination provided in [`Compiler<Msl>::add_resource_binding`]
    /// was used.
    pub fn is_resource_used(&self, model: spirv::ExecutionModel, binding: ResourceBinding) -> bool {
        unsafe {
            sys::spvc_compiler_msl_is_resource_used(
                self.compiler.ptr.as_ptr(),
                SpvExecutionModel(model as u32 as i32),
                binding.descriptor_set(),
                binding.binding(),
            )
        }
    }

    /// Returns whether the location provided in [`Compiler<Msl>::add_shader_input`]
    /// was used.
    pub fn is_shader_input_used(&self, location: u32) -> bool {
        unsafe { sys::spvc_compiler_msl_is_shader_input_used(self.compiler.ptr.as_ptr(), location) }
    }

    /// Returns whether the location provided in [`Compiler<Msl>::add_shader_output`]
    /// was used.
    pub fn is_shader_output_used(&self, location: u32) -> bool {
        unsafe {
            sys::spvc_compiler_msl_is_shader_output_used(self.compiler.ptr.as_ptr(), location)
        }
    }

    /// For a variable resource ID, report the automatically assigned resource index.
    ///
    /// If the descriptor set was part of an argument buffer, report the `[[id(N)]]`,
    /// or `[[buffer/texture/sampler]]` binding for other resources.
    ///
    /// If the resource was a combined image sampler, report the image binding for [`AutomaticResourceBindingTier::Primary`],
    /// or the sampler half for [`AutomaticResourceBindingTier::Secondary`].
    ///
    /// If no binding exists, None is returned.
    pub fn automatic_resource_binding(
        &self,
        handle: impl Into<Handle<VariableId>>,
        tier: AutomaticResourceBindingTier,
    ) -> error::Result<Option<u32>> {
        let handle = handle.into();
        let id = self.yield_id(handle)?;

        let res = match tier {
            AutomaticResourceBindingTier::Primary => unsafe {
                sys::spvc_compiler_msl_get_automatic_resource_binding(self.ptr.as_ptr(), id)
            },
            AutomaticResourceBindingTier::Secondary => unsafe {
                sys::spvc_compiler_msl_get_automatic_resource_binding_secondary(
                    self.ptr.as_ptr(),
                    id,
                )
            },
        };

        if res == u32::MAX {
            Ok(None)
        } else {
            Ok(Some(res))
        }
    }

    /// Query if a variable ID was used as a depth resource.
    ///
    /// This is meaningful for MSL since descriptor types depend on this knowledge.
    /// Cases which return true:
    /// - Images which are declared with depth = 1 image type.
    /// - Samplers which are statically used at least once with Dref opcodes.
    /// - Images which are statically used at least once with Dref opcodes.
    pub fn variable_is_depth_or_compare(
        &self,
        variable: impl Into<Handle<VariableId>>,
    ) -> error::Result<bool> {
        let variable = variable.into();
        let id = self.yield_id(variable)?;
        unsafe {
            Ok(sys::spvc_compiler_variable_is_depth_or_compare(
                self.ptr.as_ptr(),
                id,
            ))
        }
    }
}

#[cfg(test)]
mod test {
    use crate::compile::msl::CompilerOptions;
    use spirv_cross_sys::spvc_compiler_create_compiler_options;

    use crate::compile::sealed::ApplyCompilerOptions;
    use crate::error::{SpirvCrossError, ToContextError};
    use crate::Compiler;
    use crate::{targets, Module};

    static BASIC_SPV: &[u8] = include_bytes!("../../../basic.spv");

    #[test]
    pub fn msl_opts() -> Result<(), SpirvCrossError> {
        let words = Vec::from(BASIC_SPV);
        let words = Module::from_words(bytemuck::cast_slice(&words));

        let compiler: Compiler<targets::Msl> = Compiler::new(words)?;
        let resources = compiler.shader_resources()?.all_resources()?;

        let mut opts_ptr = std::ptr::null_mut();

        unsafe {
            spvc_compiler_create_compiler_options(compiler.ptr.as_ptr(), &mut opts_ptr)
                .ok(&compiler)?;
        }

        // println!("{:#?}", resources);
        let opts = CompilerOptions::default();
        unsafe {
            opts.apply(opts_ptr, &compiler)?;
        }

        // match ty.inner {
        //     TypeInner::Struct(ty) => {
        //         compiler.get_type(ty.members[0].id)?;
        //     }
        //     TypeInner::Vector { .. } => {}
        //     _ => {}
        // }
        Ok(())
    }
}