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
use std::borrow::Borrow;
use std::cell::{Cell, RefCell};
use std::ffi::CStr;
use std::str;

use libc::c_uint;
use rustc_codegen_ssa::base::{wants_msvc_seh, wants_wasm_eh};
use rustc_codegen_ssa::errors as ssa_errors;
use rustc_codegen_ssa::traits::*;
use rustc_data_structures::base_n::{ToBaseN, ALPHANUMERIC_ONLY};
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::small_c_str::SmallCStr;
use rustc_hir::def_id::DefId;
use rustc_middle::middle::codegen_fn_attrs::PatchableFunctionEntry;
use rustc_middle::mir::mono::CodegenUnit;
use rustc_middle::ty::layout::{
    FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, LayoutError, LayoutOfHelpers,
    TyAndLayout,
};
use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
use rustc_middle::{bug, span_bug};
use rustc_session::config::{
    BranchProtection, CFGuard, CFProtection, CrateType, DebugInfo, PAuthKey, PacRet,
};
use rustc_session::Session;
use rustc_span::source_map::Spanned;
use rustc_span::{Span, DUMMY_SP};
use rustc_target::abi::call::FnAbi;
use rustc_target::abi::{HasDataLayout, TargetDataLayout, VariantIdx};
use rustc_target::spec::{HasTargetSpec, RelocModel, Target, TlsModel};
use smallvec::SmallVec;

use crate::back::write::to_llvm_code_model;
use crate::callee::get_fn;
use crate::debuginfo::metadata::apply_vcall_visibility_metadata;
use crate::type_::Type;
use crate::value::Value;
use crate::{attributes, coverageinfo, debuginfo, llvm, llvm_util};

/// There is one `CodegenCx` per compilation unit. Each one has its own LLVM
/// `llvm::Context` so that several compilation units may be optimized in parallel.
/// All other LLVM data structures in the `CodegenCx` are tied to that `llvm::Context`.
pub(crate) struct CodegenCx<'ll, 'tcx> {
    pub tcx: TyCtxt<'tcx>,
    pub use_dll_storage_attrs: bool,
    pub tls_model: llvm::ThreadLocalMode,

    pub llmod: &'ll llvm::Module,
    pub llcx: &'ll llvm::Context,
    pub codegen_unit: &'tcx CodegenUnit<'tcx>,

    /// Cache instances of monomorphic and polymorphic items
    pub instances: RefCell<FxHashMap<Instance<'tcx>, &'ll Value>>,
    /// Cache generated vtables
    pub vtables:
        RefCell<FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), &'ll Value>>,
    /// Cache of constant strings,
    pub const_str_cache: RefCell<FxHashMap<String, &'ll Value>>,

    /// Cache of emitted const globals (value -> global)
    pub const_globals: RefCell<FxHashMap<&'ll Value, &'ll Value>>,

    /// List of globals for static variables which need to be passed to the
    /// LLVM function ReplaceAllUsesWith (RAUW) when codegen is complete.
    /// (We have to make sure we don't invalidate any Values referring
    /// to constants.)
    pub statics_to_rauw: RefCell<Vec<(&'ll Value, &'ll Value)>>,

    /// Statics that will be placed in the llvm.used variable
    /// See <https://llvm.org/docs/LangRef.html#the-llvm-used-global-variable> for details
    pub used_statics: RefCell<Vec<&'ll Value>>,

    /// Statics that will be placed in the llvm.compiler.used variable
    /// See <https://llvm.org/docs/LangRef.html#the-llvm-compiler-used-global-variable> for details
    pub compiler_used_statics: RefCell<Vec<&'ll Value>>,

    /// Mapping of non-scalar types to llvm types.
    pub type_lowering: RefCell<FxHashMap<(Ty<'tcx>, Option<VariantIdx>), &'ll Type>>,

    /// Mapping of scalar types to llvm types.
    pub scalar_lltypes: RefCell<FxHashMap<Ty<'tcx>, &'ll Type>>,

    pub isize_ty: &'ll Type,

    pub coverage_cx: Option<coverageinfo::CrateCoverageContext<'ll, 'tcx>>,
    pub dbg_cx: Option<debuginfo::CodegenUnitDebugContext<'ll, 'tcx>>,

    eh_personality: Cell<Option<&'ll Value>>,
    eh_catch_typeinfo: Cell<Option<&'ll Value>>,
    pub rust_try_fn: Cell<Option<(&'ll Type, &'ll Value)>>,

    intrinsics: RefCell<FxHashMap<&'static str, (&'ll Type, &'ll Value)>>,

    /// A counter that is used for generating local symbol names
    local_gen_sym_counter: Cell<usize>,

    /// `codegen_static` will sometimes create a second global variable with a
    /// different type and clear the symbol name of the original global.
    /// `global_asm!` needs to be able to find this new global so that it can
    /// compute the correct mangled symbol name to insert into the asm.
    pub renamed_statics: RefCell<FxHashMap<DefId, &'ll Value>>,
}

fn to_llvm_tls_model(tls_model: TlsModel) -> llvm::ThreadLocalMode {
    match tls_model {
        TlsModel::GeneralDynamic => llvm::ThreadLocalMode::GeneralDynamic,
        TlsModel::LocalDynamic => llvm::ThreadLocalMode::LocalDynamic,
        TlsModel::InitialExec => llvm::ThreadLocalMode::InitialExec,
        TlsModel::LocalExec => llvm::ThreadLocalMode::LocalExec,
        TlsModel::Emulated => llvm::ThreadLocalMode::GeneralDynamic,
    }
}

pub(crate) unsafe fn create_module<'ll>(
    tcx: TyCtxt<'_>,
    llcx: &'ll llvm::Context,
    mod_name: &str,
) -> &'ll llvm::Module {
    let sess = tcx.sess;
    let mod_name = SmallCStr::new(mod_name);
    let llmod = unsafe { llvm::LLVMModuleCreateWithNameInContext(mod_name.as_ptr(), llcx) };

    let mut target_data_layout = sess.target.data_layout.to_string();
    let llvm_version = llvm_util::get_version();
    if llvm_version < (18, 0, 0) {
        if sess.target.arch == "x86" || sess.target.arch == "x86_64" {
            // LLVM 18 adjusts i128 to be 128-bit aligned on x86 variants.
            // Earlier LLVMs leave this as default alignment, so remove it.
            // See https://reviews.llvm.org/D86310
            target_data_layout = target_data_layout.replace("-i128:128", "");
        }
    }

    if llvm_version < (19, 0, 0) {
        if sess.target.arch == "aarch64" || sess.target.arch.starts_with("arm64") {
            // LLVM 19 sets -Fn32 in its data layout string for 64-bit ARM
            // Earlier LLVMs leave this default, so remove it.
            // See https://github.com/llvm/llvm-project/pull/90702
            target_data_layout = target_data_layout.replace("-Fn32", "");
        }
    }

    if llvm_version < (19, 0, 0) {
        if sess.target.arch == "loongarch64" {
            // LLVM 19 updates the LoongArch64 data layout.
            // See https://github.com/llvm/llvm-project/pull/93814
            target_data_layout = target_data_layout.replace("-n32:64", "-n64");
        }
    }

    // Ensure the data-layout values hardcoded remain the defaults.
    {
        let tm = crate::back::write::create_informational_target_machine(tcx.sess, false);
        unsafe {
            llvm::LLVMRustSetDataLayoutFromTargetMachine(llmod, &tm);
        }

        let llvm_data_layout = unsafe { llvm::LLVMGetDataLayoutStr(llmod) };
        let llvm_data_layout =
            str::from_utf8(unsafe { CStr::from_ptr(llvm_data_layout) }.to_bytes())
                .expect("got a non-UTF8 data-layout from LLVM");

        if target_data_layout != llvm_data_layout {
            tcx.dcx().emit_err(crate::errors::MismatchedDataLayout {
                rustc_target: sess.opts.target_triple.to_string().as_str(),
                rustc_layout: target_data_layout.as_str(),
                llvm_target: sess.target.llvm_target.borrow(),
                llvm_layout: llvm_data_layout,
            });
        }
    }

    let data_layout = SmallCStr::new(&target_data_layout);
    unsafe {
        llvm::LLVMSetDataLayout(llmod, data_layout.as_ptr());
    }

    let llvm_target = SmallCStr::new(&sess.target.llvm_target);
    unsafe {
        llvm::LLVMRustSetNormalizedTarget(llmod, llvm_target.as_ptr());
    }

    let reloc_model = sess.relocation_model();
    if matches!(reloc_model, RelocModel::Pic | RelocModel::Pie) {
        unsafe {
            llvm::LLVMRustSetModulePICLevel(llmod);
        }
        // PIE is potentially more effective than PIC, but can only be used in executables.
        // If all our outputs are executables, then we can relax PIC to PIE.
        if reloc_model == RelocModel::Pie
            || tcx.crate_types().iter().all(|ty| *ty == CrateType::Executable)
        {
            unsafe {
                llvm::LLVMRustSetModulePIELevel(llmod);
            }
        }
    }

    // Linking object files with different code models is undefined behavior
    // because the compiler would have to generate additional code (to span
    // longer jumps) if a larger code model is used with a smaller one.
    //
    // See https://reviews.llvm.org/D52322 and https://reviews.llvm.org/D52323.
    unsafe {
        llvm::LLVMRustSetModuleCodeModel(llmod, to_llvm_code_model(sess.code_model()));
    }

    // If skipping the PLT is enabled, we need to add some module metadata
    // to ensure intrinsic calls don't use it.
    if !sess.needs_plt() {
        let avoid_plt = c"RtLibUseGOT".as_ptr();
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(llmod, llvm::LLVMModFlagBehavior::Warning, avoid_plt, 1);
        }
    }

    // Enable canonical jump tables if CFI is enabled. (See https://reviews.llvm.org/D65629.)
    if sess.is_sanitizer_cfi_canonical_jump_tables_enabled() && sess.is_sanitizer_cfi_enabled() {
        let canonical_jump_tables = c"CFI Canonical Jump Tables".as_ptr();
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(
                llmod,
                llvm::LLVMModFlagBehavior::Override,
                canonical_jump_tables,
                1,
            );
        }
    }

    // If we're normalizing integers with CFI, ensure LLVM generated functions do the same.
    // See https://github.com/llvm/llvm-project/pull/104826
    if sess.is_sanitizer_cfi_normalize_integers_enabled() {
        let cfi_normalize_integers = c"cfi-normalize-integers".as_ptr().cast();
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(
                llmod,
                llvm::LLVMModFlagBehavior::Override,
                cfi_normalize_integers,
                1,
            );
        }
    }

    // Enable LTO unit splitting if specified or if CFI is enabled. (See https://reviews.llvm.org/D53891.)
    if sess.is_split_lto_unit_enabled() || sess.is_sanitizer_cfi_enabled() {
        let enable_split_lto_unit = c"EnableSplitLTOUnit".as_ptr();
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(
                llmod,
                llvm::LLVMModFlagBehavior::Override,
                enable_split_lto_unit,
                1,
            );
        }
    }

    // Add "kcfi" module flag if KCFI is enabled. (See https://reviews.llvm.org/D119296.)
    if sess.is_sanitizer_kcfi_enabled() {
        let kcfi = c"kcfi".as_ptr();
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(llmod, llvm::LLVMModFlagBehavior::Override, kcfi, 1);
        }

        // Add "kcfi-offset" module flag with -Z patchable-function-entry (See
        // https://reviews.llvm.org/D141172).
        let pfe =
            PatchableFunctionEntry::from_config(sess.opts.unstable_opts.patchable_function_entry);
        if pfe.prefix() > 0 {
            let kcfi_offset = c"kcfi-offset".as_ptr().cast();
            unsafe {
                llvm::LLVMRustAddModuleFlagU32(
                    llmod,
                    llvm::LLVMModFlagBehavior::Override,
                    kcfi_offset,
                    pfe.prefix().into(),
                );
            }
        }
    }

    // Control Flow Guard is currently only supported by the MSVC linker on Windows.
    if sess.target.is_like_msvc {
        unsafe {
            match sess.opts.cg.control_flow_guard {
                CFGuard::Disabled => {}
                CFGuard::NoChecks => {
                    // Set `cfguard=1` module flag to emit metadata only.
                    llvm::LLVMRustAddModuleFlagU32(
                        llmod,
                        llvm::LLVMModFlagBehavior::Warning,
                        c"cfguard".as_ptr() as *const _,
                        1,
                    )
                }
                CFGuard::Checks => {
                    // Set `cfguard=2` module flag to emit metadata and checks.
                    llvm::LLVMRustAddModuleFlagU32(
                        llmod,
                        llvm::LLVMModFlagBehavior::Warning,
                        c"cfguard".as_ptr() as *const _,
                        2,
                    )
                }
            }
        }
    }

    if let Some(BranchProtection { bti, pac_ret }) = sess.opts.unstable_opts.branch_protection {
        if sess.target.arch == "aarch64" {
            unsafe {
                llvm::LLVMRustAddModuleFlagU32(
                    llmod,
                    llvm::LLVMModFlagBehavior::Min,
                    c"branch-target-enforcement".as_ptr(),
                    bti.into(),
                );
                llvm::LLVMRustAddModuleFlagU32(
                    llmod,
                    llvm::LLVMModFlagBehavior::Min,
                    c"sign-return-address".as_ptr(),
                    pac_ret.is_some().into(),
                );
                let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, key: PAuthKey::A });
                llvm::LLVMRustAddModuleFlagU32(
                    llmod,
                    llvm::LLVMModFlagBehavior::Min,
                    c"sign-return-address-all".as_ptr(),
                    pac_opts.leaf.into(),
                );
                llvm::LLVMRustAddModuleFlagU32(
                    llmod,
                    llvm::LLVMModFlagBehavior::Min,
                    c"sign-return-address-with-bkey".as_ptr(),
                    u32::from(pac_opts.key == PAuthKey::B),
                );
            }
        } else {
            bug!(
                "branch-protection used on non-AArch64 target; \
                  this should be checked in rustc_session."
            );
        }
    }

    // Pass on the control-flow protection flags to LLVM (equivalent to `-fcf-protection` in Clang).
    if let CFProtection::Branch | CFProtection::Full = sess.opts.unstable_opts.cf_protection {
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(
                llmod,
                llvm::LLVMModFlagBehavior::Override,
                c"cf-protection-branch".as_ptr(),
                1,
            );
        }
    }
    if let CFProtection::Return | CFProtection::Full = sess.opts.unstable_opts.cf_protection {
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(
                llmod,
                llvm::LLVMModFlagBehavior::Override,
                c"cf-protection-return".as_ptr(),
                1,
            );
        }
    }

    if sess.opts.unstable_opts.virtual_function_elimination {
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(
                llmod,
                llvm::LLVMModFlagBehavior::Error,
                c"Virtual Function Elim".as_ptr(),
                1,
            );
        }
    }

    // Set module flag to enable Windows EHCont Guard (/guard:ehcont).
    if sess.opts.unstable_opts.ehcont_guard {
        unsafe {
            llvm::LLVMRustAddModuleFlagU32(
                llmod,
                llvm::LLVMModFlagBehavior::Warning,
                c"ehcontguard".as_ptr() as *const _,
                1,
            )
        }
    }

    // Insert `llvm.ident` metadata.
    //
    // On the wasm targets it will get hooked up to the "producer" sections
    // `processed-by` information.
    #[allow(clippy::option_env_unwrap)]
    let rustc_producer =
        format!("rustc version {}", option_env!("CFG_VERSION").expect("CFG_VERSION"));
    let name_metadata = unsafe {
        llvm::LLVMMDStringInContext(
            llcx,
            rustc_producer.as_ptr().cast(),
            rustc_producer.as_bytes().len() as c_uint,
        )
    };
    unsafe {
        llvm::LLVMAddNamedMetadataOperand(
            llmod,
            c"llvm.ident".as_ptr(),
            llvm::LLVMMDNodeInContext(llcx, &name_metadata, 1),
        );
    }

    // Emit RISC-V specific target-abi metadata
    // to workaround lld as the LTO plugin not
    // correctly setting target-abi for the LTO object
    // FIXME: https://github.com/llvm/llvm-project/issues/50591
    // If llvm_abiname is empty, emit nothing.
    let llvm_abiname = &sess.target.options.llvm_abiname;
    if matches!(sess.target.arch.as_ref(), "riscv32" | "riscv64") && !llvm_abiname.is_empty() {
        unsafe {
            llvm::LLVMRustAddModuleFlagString(
                llmod,
                llvm::LLVMModFlagBehavior::Error,
                c"target-abi".as_ptr(),
                llvm_abiname.as_ptr().cast(),
                llvm_abiname.len(),
            );
        }
    }

    // Add module flags specified via -Z llvm_module_flag
    for (key, value, behavior) in &sess.opts.unstable_opts.llvm_module_flag {
        let key = format!("{key}\0");
        let behavior = match behavior.as_str() {
            "error" => llvm::LLVMModFlagBehavior::Error,
            "warning" => llvm::LLVMModFlagBehavior::Warning,
            "require" => llvm::LLVMModFlagBehavior::Require,
            "override" => llvm::LLVMModFlagBehavior::Override,
            "append" => llvm::LLVMModFlagBehavior::Append,
            "appendunique" => llvm::LLVMModFlagBehavior::AppendUnique,
            "max" => llvm::LLVMModFlagBehavior::Max,
            "min" => llvm::LLVMModFlagBehavior::Min,
            // We already checked this during option parsing
            _ => unreachable!(),
        };
        unsafe { llvm::LLVMRustAddModuleFlagU32(llmod, behavior, key.as_ptr().cast(), *value) }
    }

    llmod
}

impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
    pub(crate) fn new(
        tcx: TyCtxt<'tcx>,
        codegen_unit: &'tcx CodegenUnit<'tcx>,
        llvm_module: &'ll crate::ModuleLlvm,
    ) -> Self {
        // An interesting part of Windows which MSVC forces our hand on (and
        // apparently MinGW didn't) is the usage of `dllimport` and `dllexport`
        // attributes in LLVM IR as well as native dependencies (in C these
        // correspond to `__declspec(dllimport)`).
        //
        // LD (BFD) in MinGW mode can often correctly guess `dllexport` but
        // relying on that can result in issues like #50176.
        // LLD won't support that and expects symbols with proper attributes.
        // Because of that we make MinGW target emit dllexport just like MSVC.
        // When it comes to dllimport we use it for constants but for functions
        // rely on the linker to do the right thing. Opposed to dllexport this
        // task is easy for them (both LD and LLD) and allows us to easily use
        // symbols from static libraries in shared libraries.
        //
        // Whenever a dynamic library is built on Windows it must have its public
        // interface specified by functions tagged with `dllexport` or otherwise
        // they're not available to be linked against. This poses a few problems
        // for the compiler, some of which are somewhat fundamental, but we use
        // the `use_dll_storage_attrs` variable below to attach the `dllexport`
        // attribute to all LLVM functions that are exported e.g., they're
        // already tagged with external linkage). This is suboptimal for a few
        // reasons:
        //
        // * If an object file will never be included in a dynamic library,
        //   there's no need to attach the dllexport attribute. Most object
        //   files in Rust are not destined to become part of a dll as binaries
        //   are statically linked by default.
        // * If the compiler is emitting both an rlib and a dylib, the same
        //   source object file is currently used but with MSVC this may be less
        //   feasible. The compiler may be able to get around this, but it may
        //   involve some invasive changes to deal with this.
        //
        // The flip side of this situation is that whenever you link to a dll and
        // you import a function from it, the import should be tagged with
        // `dllimport`. At this time, however, the compiler does not emit
        // `dllimport` for any declarations other than constants (where it is
        // required), which is again suboptimal for even more reasons!
        //
        // * Calling a function imported from another dll without using
        //   `dllimport` causes the linker/compiler to have extra overhead (one
        //   `jmp` instruction on x86) when calling the function.
        // * The same object file may be used in different circumstances, so a
        //   function may be imported from a dll if the object is linked into a
        //   dll, but it may be just linked against if linked into an rlib.
        // * The compiler has no knowledge about whether native functions should
        //   be tagged dllimport or not.
        //
        // For now the compiler takes the perf hit (I do not have any numbers to
        // this effect) by marking very little as `dllimport` and praying the
        // linker will take care of everything. Fixing this problem will likely
        // require adding a few attributes to Rust itself (feature gated at the
        // start) and then strongly recommending static linkage on Windows!
        let use_dll_storage_attrs = tcx.sess.target.is_like_windows;

        let tls_model = to_llvm_tls_model(tcx.sess.tls_model());

        let (llcx, llmod) = (&*llvm_module.llcx, llvm_module.llmod());

        let coverage_cx =
            tcx.sess.instrument_coverage().then(coverageinfo::CrateCoverageContext::new);

        let dbg_cx = if tcx.sess.opts.debuginfo != DebugInfo::None {
            let dctx = debuginfo::CodegenUnitDebugContext::new(llmod);
            debuginfo::metadata::build_compile_unit_di_node(
                tcx,
                codegen_unit.name().as_str(),
                &dctx,
            );
            Some(dctx)
        } else {
            None
        };

        let isize_ty = Type::ix_llcx(llcx, tcx.data_layout.pointer_size.bits());

        CodegenCx {
            tcx,
            use_dll_storage_attrs,
            tls_model,
            llmod,
            llcx,
            codegen_unit,
            instances: Default::default(),
            vtables: Default::default(),
            const_str_cache: Default::default(),
            const_globals: Default::default(),
            statics_to_rauw: RefCell::new(Vec::new()),
            used_statics: RefCell::new(Vec::new()),
            compiler_used_statics: RefCell::new(Vec::new()),
            type_lowering: Default::default(),
            scalar_lltypes: Default::default(),
            isize_ty,
            coverage_cx,
            dbg_cx,
            eh_personality: Cell::new(None),
            eh_catch_typeinfo: Cell::new(None),
            rust_try_fn: Cell::new(None),
            intrinsics: Default::default(),
            local_gen_sym_counter: Cell::new(0),
            renamed_statics: Default::default(),
        }
    }

    pub(crate) fn statics_to_rauw(&self) -> &RefCell<Vec<(&'ll Value, &'ll Value)>> {
        &self.statics_to_rauw
    }

    #[inline]
    pub(crate) fn coverage_context(
        &self,
    ) -> Option<&coverageinfo::CrateCoverageContext<'ll, 'tcx>> {
        self.coverage_cx.as_ref()
    }

    pub(crate) fn create_used_variable_impl(&self, name: &'static CStr, values: &[&'ll Value]) {
        let array = self.const_array(self.type_ptr(), values);

        unsafe {
            let g = llvm::LLVMAddGlobal(self.llmod, self.val_ty(array), name.as_ptr());
            llvm::LLVMSetInitializer(g, array);
            llvm::LLVMRustSetLinkage(g, llvm::Linkage::AppendingLinkage);
            llvm::LLVMSetSection(g, c"llvm.metadata".as_ptr());
        }
    }
}

impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
    fn vtables(
        &self,
    ) -> &RefCell<FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), &'ll Value>>
    {
        &self.vtables
    }

    fn apply_vcall_visibility_metadata(
        &self,
        ty: Ty<'tcx>,
        poly_trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
        vtable: &'ll Value,
    ) {
        apply_vcall_visibility_metadata(self, ty, poly_trait_ref, vtable);
    }

    fn get_fn(&self, instance: Instance<'tcx>) -> &'ll Value {
        get_fn(self, instance)
    }

    fn get_fn_addr(&self, instance: Instance<'tcx>) -> &'ll Value {
        get_fn(self, instance)
    }

    fn eh_personality(&self) -> &'ll Value {
        // The exception handling personality function.
        //
        // If our compilation unit has the `eh_personality` lang item somewhere
        // within it, then we just need to codegen that. Otherwise, we're
        // building an rlib which will depend on some upstream implementation of
        // this function, so we just codegen a generic reference to it. We don't
        // specify any of the types for the function, we just make it a symbol
        // that LLVM can later use.
        //
        // Note that MSVC is a little special here in that we don't use the
        // `eh_personality` lang item at all. Currently LLVM has support for
        // both Dwarf and SEH unwind mechanisms for MSVC targets and uses the
        // *name of the personality function* to decide what kind of unwind side
        // tables/landing pads to emit. It looks like Dwarf is used by default,
        // injecting a dependency on the `_Unwind_Resume` symbol for resuming
        // an "exception", but for MSVC we want to force SEH. This means that we
        // can't actually have the personality function be our standard
        // `rust_eh_personality` function, but rather we wired it up to the
        // CRT's custom personality function, which forces LLVM to consider
        // landing pads as "landing pads for SEH".
        if let Some(llpersonality) = self.eh_personality.get() {
            return llpersonality;
        }

        let name = if wants_msvc_seh(self.sess()) {
            Some("__CxxFrameHandler3")
        } else if wants_wasm_eh(self.sess()) {
            // LLVM specifically tests for the name of the personality function
            // There is no need for this function to exist anywhere, it will
            // not be called. However, its name has to be "__gxx_wasm_personality_v0"
            // for native wasm exceptions.
            Some("__gxx_wasm_personality_v0")
        } else {
            None
        };

        let tcx = self.tcx;
        let llfn = match tcx.lang_items().eh_personality() {
            Some(def_id) if name.is_none() => self.get_fn_addr(ty::Instance::expect_resolve(
                tcx,
                ty::ParamEnv::reveal_all(),
                def_id,
                ty::List::empty(),
                DUMMY_SP,
            )),
            _ => {
                let name = name.unwrap_or("rust_eh_personality");
                if let Some(llfn) = self.get_declared_value(name) {
                    llfn
                } else {
                    let fty = self.type_variadic_func(&[], self.type_i32());
                    let llfn = self.declare_cfn(name, llvm::UnnamedAddr::Global, fty);
                    let target_cpu = attributes::target_cpu_attr(self);
                    attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[target_cpu]);
                    llfn
                }
            }
        };
        self.eh_personality.set(Some(llfn));
        llfn
    }

    fn sess(&self) -> &Session {
        self.tcx.sess
    }

    fn codegen_unit(&self) -> &'tcx CodegenUnit<'tcx> {
        self.codegen_unit
    }

    fn set_frame_pointer_type(&self, llfn: &'ll Value) {
        if let Some(attr) = attributes::frame_pointer_type_attr(self) {
            attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &[attr]);
        }
    }

    fn apply_target_cpu_attr(&self, llfn: &'ll Value) {
        let mut attrs = SmallVec::<[_; 2]>::new();
        attrs.push(attributes::target_cpu_attr(self));
        attrs.extend(attributes::tune_cpu_attr(self));
        attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &attrs);
    }

    fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> {
        let entry_name = self.sess().target.entry_name.as_ref();
        if self.get_declared_value(entry_name).is_none() {
            Some(self.declare_entry_fn(
                entry_name,
                self.sess().target.entry_abi.into(),
                llvm::UnnamedAddr::Global,
                fn_type,
            ))
        } else {
            // If the symbol already exists, it is an error: for example, the user wrote
            // #[no_mangle] extern "C" fn main(..) {..}
            // instead of #[start]
            None
        }
    }
}

impl<'ll> CodegenCx<'ll, '_> {
    pub(crate) fn get_intrinsic(&self, key: &str) -> (&'ll Type, &'ll Value) {
        if let Some(v) = self.intrinsics.borrow().get(key).cloned() {
            return v;
        }

        self.declare_intrinsic(key).unwrap_or_else(|| bug!("unknown intrinsic '{}'", key))
    }

    fn insert_intrinsic(
        &self,
        name: &'static str,
        args: Option<&[&'ll llvm::Type]>,
        ret: &'ll llvm::Type,
    ) -> (&'ll llvm::Type, &'ll llvm::Value) {
        let fn_ty = if let Some(args) = args {
            self.type_func(args, ret)
        } else {
            self.type_variadic_func(&[], ret)
        };
        let f = self.declare_cfn(name, llvm::UnnamedAddr::No, fn_ty);
        self.intrinsics.borrow_mut().insert(name, (fn_ty, f));
        (fn_ty, f)
    }

    fn declare_intrinsic(&self, key: &str) -> Option<(&'ll Type, &'ll Value)> {
        macro_rules! ifn {
            ($name:expr, fn() -> $ret:expr) => (
                if key == $name {
                    return Some(self.insert_intrinsic($name, Some(&[]), $ret));
                }
            );
            ($name:expr, fn(...) -> $ret:expr) => (
                if key == $name {
                    return Some(self.insert_intrinsic($name, None, $ret));
                }
            );
            ($name:expr, fn($($arg:expr),*) -> $ret:expr) => (
                if key == $name {
                    return Some(self.insert_intrinsic($name, Some(&[$($arg),*]), $ret));
                }
            );
        }
        macro_rules! mk_struct {
            ($($field_ty:expr),*) => (self.type_struct( &[$($field_ty),*], false))
        }

        let ptr = self.type_ptr();
        let void = self.type_void();
        let i1 = self.type_i1();
        let t_i8 = self.type_i8();
        let t_i16 = self.type_i16();
        let t_i32 = self.type_i32();
        let t_i64 = self.type_i64();
        let t_i128 = self.type_i128();
        let t_isize = self.type_isize();
        let t_f16 = self.type_f16();
        let t_f32 = self.type_f32();
        let t_f64 = self.type_f64();
        let t_f128 = self.type_f128();
        let t_metadata = self.type_metadata();
        let t_token = self.type_token();

        ifn!("llvm.wasm.get.exception", fn(t_token) -> ptr);
        ifn!("llvm.wasm.get.ehselector", fn(t_token) -> t_i32);

        ifn!("llvm.wasm.trunc.unsigned.i32.f32", fn(t_f32) -> t_i32);
        ifn!("llvm.wasm.trunc.unsigned.i32.f64", fn(t_f64) -> t_i32);
        ifn!("llvm.wasm.trunc.unsigned.i64.f32", fn(t_f32) -> t_i64);
        ifn!("llvm.wasm.trunc.unsigned.i64.f64", fn(t_f64) -> t_i64);
        ifn!("llvm.wasm.trunc.signed.i32.f32", fn(t_f32) -> t_i32);
        ifn!("llvm.wasm.trunc.signed.i32.f64", fn(t_f64) -> t_i32);
        ifn!("llvm.wasm.trunc.signed.i64.f32", fn(t_f32) -> t_i64);
        ifn!("llvm.wasm.trunc.signed.i64.f64", fn(t_f64) -> t_i64);

        ifn!("llvm.fptosi.sat.i8.f32", fn(t_f32) -> t_i8);
        ifn!("llvm.fptosi.sat.i16.f32", fn(t_f32) -> t_i16);
        ifn!("llvm.fptosi.sat.i32.f32", fn(t_f32) -> t_i32);
        ifn!("llvm.fptosi.sat.i64.f32", fn(t_f32) -> t_i64);
        ifn!("llvm.fptosi.sat.i128.f32", fn(t_f32) -> t_i128);
        ifn!("llvm.fptosi.sat.i8.f64", fn(t_f64) -> t_i8);
        ifn!("llvm.fptosi.sat.i16.f64", fn(t_f64) -> t_i16);
        ifn!("llvm.fptosi.sat.i32.f64", fn(t_f64) -> t_i32);
        ifn!("llvm.fptosi.sat.i64.f64", fn(t_f64) -> t_i64);
        ifn!("llvm.fptosi.sat.i128.f64", fn(t_f64) -> t_i128);

        ifn!("llvm.fptoui.sat.i8.f32", fn(t_f32) -> t_i8);
        ifn!("llvm.fptoui.sat.i16.f32", fn(t_f32) -> t_i16);
        ifn!("llvm.fptoui.sat.i32.f32", fn(t_f32) -> t_i32);
        ifn!("llvm.fptoui.sat.i64.f32", fn(t_f32) -> t_i64);
        ifn!("llvm.fptoui.sat.i128.f32", fn(t_f32) -> t_i128);
        ifn!("llvm.fptoui.sat.i8.f64", fn(t_f64) -> t_i8);
        ifn!("llvm.fptoui.sat.i16.f64", fn(t_f64) -> t_i16);
        ifn!("llvm.fptoui.sat.i32.f64", fn(t_f64) -> t_i32);
        ifn!("llvm.fptoui.sat.i64.f64", fn(t_f64) -> t_i64);
        ifn!("llvm.fptoui.sat.i128.f64", fn(t_f64) -> t_i128);

        ifn!("llvm.trap", fn() -> void);
        ifn!("llvm.debugtrap", fn() -> void);
        ifn!("llvm.frameaddress", fn(t_i32) -> ptr);

        ifn!("llvm.powi.f16.i32", fn(t_f16, t_i32) -> t_f16);
        ifn!("llvm.powi.f32.i32", fn(t_f32, t_i32) -> t_f32);
        ifn!("llvm.powi.f64.i32", fn(t_f64, t_i32) -> t_f64);
        ifn!("llvm.powi.f128.i32", fn(t_f128, t_i32) -> t_f128);

        ifn!("llvm.pow.f16", fn(t_f16, t_f16) -> t_f16);
        ifn!("llvm.pow.f32", fn(t_f32, t_f32) -> t_f32);
        ifn!("llvm.pow.f64", fn(t_f64, t_f64) -> t_f64);
        ifn!("llvm.pow.f128", fn(t_f128, t_f128) -> t_f128);

        ifn!("llvm.sqrt.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.sqrt.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.sqrt.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.sqrt.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.sin.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.sin.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.sin.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.sin.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.cos.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.cos.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.cos.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.cos.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.exp.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.exp.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.exp.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.exp.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.exp2.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.exp2.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.exp2.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.exp2.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.log.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.log.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.log.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.log.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.log10.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.log10.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.log10.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.log10.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.log2.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.log2.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.log2.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.log2.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.fma.f16", fn(t_f16, t_f16, t_f16) -> t_f16);
        ifn!("llvm.fma.f32", fn(t_f32, t_f32, t_f32) -> t_f32);
        ifn!("llvm.fma.f64", fn(t_f64, t_f64, t_f64) -> t_f64);
        ifn!("llvm.fma.f128", fn(t_f128, t_f128, t_f128) -> t_f128);

        ifn!("llvm.fabs.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.fabs.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.fabs.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.fabs.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.minnum.f16", fn(t_f16, t_f16) -> t_f16);
        ifn!("llvm.minnum.f32", fn(t_f32, t_f32) -> t_f32);
        ifn!("llvm.minnum.f64", fn(t_f64, t_f64) -> t_f64);
        ifn!("llvm.minnum.f128", fn(t_f128, t_f128) -> t_f128);

        ifn!("llvm.maxnum.f16", fn(t_f16, t_f16) -> t_f16);
        ifn!("llvm.maxnum.f32", fn(t_f32, t_f32) -> t_f32);
        ifn!("llvm.maxnum.f64", fn(t_f64, t_f64) -> t_f64);
        ifn!("llvm.maxnum.f128", fn(t_f128, t_f128) -> t_f128);

        ifn!("llvm.floor.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.floor.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.floor.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.floor.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.ceil.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.ceil.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.ceil.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.ceil.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.trunc.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.trunc.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.trunc.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.trunc.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.copysign.f16", fn(t_f16, t_f16) -> t_f16);
        ifn!("llvm.copysign.f32", fn(t_f32, t_f32) -> t_f32);
        ifn!("llvm.copysign.f64", fn(t_f64, t_f64) -> t_f64);
        ifn!("llvm.copysign.f128", fn(t_f128, t_f128) -> t_f128);

        ifn!("llvm.round.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.round.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.round.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.round.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.roundeven.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.roundeven.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.roundeven.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.roundeven.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.rint.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.rint.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.rint.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.rint.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.nearbyint.f16", fn(t_f16) -> t_f16);
        ifn!("llvm.nearbyint.f32", fn(t_f32) -> t_f32);
        ifn!("llvm.nearbyint.f64", fn(t_f64) -> t_f64);
        ifn!("llvm.nearbyint.f128", fn(t_f128) -> t_f128);

        ifn!("llvm.ctpop.i8", fn(t_i8) -> t_i8);
        ifn!("llvm.ctpop.i16", fn(t_i16) -> t_i16);
        ifn!("llvm.ctpop.i32", fn(t_i32) -> t_i32);
        ifn!("llvm.ctpop.i64", fn(t_i64) -> t_i64);
        ifn!("llvm.ctpop.i128", fn(t_i128) -> t_i128);

        ifn!("llvm.ctlz.i8", fn(t_i8, i1) -> t_i8);
        ifn!("llvm.ctlz.i16", fn(t_i16, i1) -> t_i16);
        ifn!("llvm.ctlz.i32", fn(t_i32, i1) -> t_i32);
        ifn!("llvm.ctlz.i64", fn(t_i64, i1) -> t_i64);
        ifn!("llvm.ctlz.i128", fn(t_i128, i1) -> t_i128);

        ifn!("llvm.cttz.i8", fn(t_i8, i1) -> t_i8);
        ifn!("llvm.cttz.i16", fn(t_i16, i1) -> t_i16);
        ifn!("llvm.cttz.i32", fn(t_i32, i1) -> t_i32);
        ifn!("llvm.cttz.i64", fn(t_i64, i1) -> t_i64);
        ifn!("llvm.cttz.i128", fn(t_i128, i1) -> t_i128);

        ifn!("llvm.bswap.i16", fn(t_i16) -> t_i16);
        ifn!("llvm.bswap.i32", fn(t_i32) -> t_i32);
        ifn!("llvm.bswap.i64", fn(t_i64) -> t_i64);
        ifn!("llvm.bswap.i128", fn(t_i128) -> t_i128);

        ifn!("llvm.bitreverse.i8", fn(t_i8) -> t_i8);
        ifn!("llvm.bitreverse.i16", fn(t_i16) -> t_i16);
        ifn!("llvm.bitreverse.i32", fn(t_i32) -> t_i32);
        ifn!("llvm.bitreverse.i64", fn(t_i64) -> t_i64);
        ifn!("llvm.bitreverse.i128", fn(t_i128) -> t_i128);

        ifn!("llvm.fshl.i8", fn(t_i8, t_i8, t_i8) -> t_i8);
        ifn!("llvm.fshl.i16", fn(t_i16, t_i16, t_i16) -> t_i16);
        ifn!("llvm.fshl.i32", fn(t_i32, t_i32, t_i32) -> t_i32);
        ifn!("llvm.fshl.i64", fn(t_i64, t_i64, t_i64) -> t_i64);
        ifn!("llvm.fshl.i128", fn(t_i128, t_i128, t_i128) -> t_i128);

        ifn!("llvm.fshr.i8", fn(t_i8, t_i8, t_i8) -> t_i8);
        ifn!("llvm.fshr.i16", fn(t_i16, t_i16, t_i16) -> t_i16);
        ifn!("llvm.fshr.i32", fn(t_i32, t_i32, t_i32) -> t_i32);
        ifn!("llvm.fshr.i64", fn(t_i64, t_i64, t_i64) -> t_i64);
        ifn!("llvm.fshr.i128", fn(t_i128, t_i128, t_i128) -> t_i128);

        ifn!("llvm.sadd.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1});
        ifn!("llvm.sadd.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1});
        ifn!("llvm.sadd.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1});
        ifn!("llvm.sadd.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1});
        ifn!("llvm.sadd.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1});

        ifn!("llvm.uadd.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1});
        ifn!("llvm.uadd.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1});
        ifn!("llvm.uadd.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1});
        ifn!("llvm.uadd.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1});
        ifn!("llvm.uadd.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1});

        ifn!("llvm.ssub.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1});
        ifn!("llvm.ssub.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1});
        ifn!("llvm.ssub.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1});
        ifn!("llvm.ssub.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1});
        ifn!("llvm.ssub.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1});

        ifn!("llvm.usub.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1});
        ifn!("llvm.usub.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1});
        ifn!("llvm.usub.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1});
        ifn!("llvm.usub.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1});
        ifn!("llvm.usub.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1});

        ifn!("llvm.smul.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1});
        ifn!("llvm.smul.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1});
        ifn!("llvm.smul.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1});
        ifn!("llvm.smul.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1});
        ifn!("llvm.smul.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1});

        ifn!("llvm.umul.with.overflow.i8", fn(t_i8, t_i8) -> mk_struct! {t_i8, i1});
        ifn!("llvm.umul.with.overflow.i16", fn(t_i16, t_i16) -> mk_struct! {t_i16, i1});
        ifn!("llvm.umul.with.overflow.i32", fn(t_i32, t_i32) -> mk_struct! {t_i32, i1});
        ifn!("llvm.umul.with.overflow.i64", fn(t_i64, t_i64) -> mk_struct! {t_i64, i1});
        ifn!("llvm.umul.with.overflow.i128", fn(t_i128, t_i128) -> mk_struct! {t_i128, i1});

        ifn!("llvm.sadd.sat.i8", fn(t_i8, t_i8) -> t_i8);
        ifn!("llvm.sadd.sat.i16", fn(t_i16, t_i16) -> t_i16);
        ifn!("llvm.sadd.sat.i32", fn(t_i32, t_i32) -> t_i32);
        ifn!("llvm.sadd.sat.i64", fn(t_i64, t_i64) -> t_i64);
        ifn!("llvm.sadd.sat.i128", fn(t_i128, t_i128) -> t_i128);

        ifn!("llvm.uadd.sat.i8", fn(t_i8, t_i8) -> t_i8);
        ifn!("llvm.uadd.sat.i16", fn(t_i16, t_i16) -> t_i16);
        ifn!("llvm.uadd.sat.i32", fn(t_i32, t_i32) -> t_i32);
        ifn!("llvm.uadd.sat.i64", fn(t_i64, t_i64) -> t_i64);
        ifn!("llvm.uadd.sat.i128", fn(t_i128, t_i128) -> t_i128);

        ifn!("llvm.ssub.sat.i8", fn(t_i8, t_i8) -> t_i8);
        ifn!("llvm.ssub.sat.i16", fn(t_i16, t_i16) -> t_i16);
        ifn!("llvm.ssub.sat.i32", fn(t_i32, t_i32) -> t_i32);
        ifn!("llvm.ssub.sat.i64", fn(t_i64, t_i64) -> t_i64);
        ifn!("llvm.ssub.sat.i128", fn(t_i128, t_i128) -> t_i128);

        ifn!("llvm.usub.sat.i8", fn(t_i8, t_i8) -> t_i8);
        ifn!("llvm.usub.sat.i16", fn(t_i16, t_i16) -> t_i16);
        ifn!("llvm.usub.sat.i32", fn(t_i32, t_i32) -> t_i32);
        ifn!("llvm.usub.sat.i64", fn(t_i64, t_i64) -> t_i64);
        ifn!("llvm.usub.sat.i128", fn(t_i128, t_i128) -> t_i128);

        ifn!("llvm.lifetime.start.p0i8", fn(t_i64, ptr) -> void);
        ifn!("llvm.lifetime.end.p0i8", fn(t_i64, ptr) -> void);

        // FIXME: This is an infinitesimally small portion of the types you can
        // pass to this intrinsic, if we can ever lazily register intrinsics we
        // should register these when they're used, that way any type can be
        // passed.
        ifn!("llvm.is.constant.i1", fn(i1) -> i1);
        ifn!("llvm.is.constant.i8", fn(t_i8) -> i1);
        ifn!("llvm.is.constant.i16", fn(t_i16) -> i1);
        ifn!("llvm.is.constant.i32", fn(t_i32) -> i1);
        ifn!("llvm.is.constant.i64", fn(t_i64) -> i1);
        ifn!("llvm.is.constant.i128", fn(t_i128) -> i1);
        ifn!("llvm.is.constant.isize", fn(t_isize) -> i1);
        ifn!("llvm.is.constant.f16", fn(t_f16) -> i1);
        ifn!("llvm.is.constant.f32", fn(t_f32) -> i1);
        ifn!("llvm.is.constant.f64", fn(t_f64) -> i1);
        ifn!("llvm.is.constant.f128", fn(t_f128) -> i1);
        ifn!("llvm.is.constant.ptr", fn(ptr) -> i1);

        ifn!("llvm.expect.i1", fn(i1, i1) -> i1);
        ifn!("llvm.eh.typeid.for", fn(ptr) -> t_i32);
        ifn!("llvm.localescape", fn(...) -> void);
        ifn!("llvm.localrecover", fn(ptr, ptr, t_i32) -> ptr);
        ifn!("llvm.x86.seh.recoverfp", fn(ptr, ptr) -> ptr);

        ifn!("llvm.assume", fn(i1) -> void);
        ifn!("llvm.prefetch", fn(ptr, t_i32, t_i32, t_i32) -> void);

        // This isn't an "LLVM intrinsic", but LLVM's optimization passes
        // recognize it like one (including turning it into `bcmp` sometimes)
        // and we use it to implement intrinsics like `raw_eq` and `compare_bytes`
        match self.sess().target.arch.as_ref() {
            "avr" | "msp430" => ifn!("memcmp", fn(ptr, ptr, t_isize) -> t_i16),
            _ => ifn!("memcmp", fn(ptr, ptr, t_isize) -> t_i32),
        }

        // variadic intrinsics
        ifn!("llvm.va_start", fn(ptr) -> void);
        ifn!("llvm.va_end", fn(ptr) -> void);
        ifn!("llvm.va_copy", fn(ptr, ptr) -> void);

        if self.sess().instrument_coverage() {
            ifn!("llvm.instrprof.increment", fn(ptr, t_i64, t_i32, t_i32) -> void);
        }

        ifn!("llvm.type.test", fn(ptr, t_metadata) -> i1);
        ifn!("llvm.type.checked.load", fn(ptr, t_i32, t_metadata) -> mk_struct! {ptr, i1});

        if self.sess().opts.debuginfo != DebugInfo::None {
            ifn!("llvm.dbg.declare", fn(t_metadata, t_metadata) -> void);
            ifn!("llvm.dbg.value", fn(t_metadata, t_i64, t_metadata) -> void);
        }

        ifn!("llvm.ptrmask", fn(ptr, t_isize) -> ptr);

        None
    }

    pub(crate) fn eh_catch_typeinfo(&self) -> &'ll Value {
        if let Some(eh_catch_typeinfo) = self.eh_catch_typeinfo.get() {
            return eh_catch_typeinfo;
        }
        let tcx = self.tcx;
        assert!(self.sess().target.os == "emscripten");
        let eh_catch_typeinfo = match tcx.lang_items().eh_catch_typeinfo() {
            Some(def_id) => self.get_static(def_id),
            _ => {
                let ty = self.type_struct(&[self.type_ptr(), self.type_ptr()], false);
                self.declare_global("rust_eh_catch_typeinfo", ty)
            }
        };
        self.eh_catch_typeinfo.set(Some(eh_catch_typeinfo));
        eh_catch_typeinfo
    }
}

impl CodegenCx<'_, '_> {
    /// Generates a new symbol name with the given prefix. This symbol name must
    /// only be used for definitions with `internal` or `private` linkage.
    pub(crate) fn generate_local_symbol_name(&self, prefix: &str) -> String {
        let idx = self.local_gen_sym_counter.get();
        self.local_gen_sym_counter.set(idx + 1);
        // Include a '.' character, so there can be no accidental conflicts with
        // user defined names
        let mut name = String::with_capacity(prefix.len() + 6);
        name.push_str(prefix);
        name.push('.');
        name.push_str(&(idx as u64).to_base(ALPHANUMERIC_ONLY));
        name
    }
}

impl HasDataLayout for CodegenCx<'_, '_> {
    #[inline]
    fn data_layout(&self) -> &TargetDataLayout {
        &self.tcx.data_layout
    }
}

impl HasTargetSpec for CodegenCx<'_, '_> {
    #[inline]
    fn target_spec(&self) -> &Target {
        &self.tcx.sess.target
    }
}

impl<'tcx> ty::layout::HasTyCtxt<'tcx> for CodegenCx<'_, 'tcx> {
    #[inline]
    fn tcx(&self) -> TyCtxt<'tcx> {
        self.tcx
    }
}

impl<'tcx, 'll> HasParamEnv<'tcx> for CodegenCx<'ll, 'tcx> {
    fn param_env(&self) -> ty::ParamEnv<'tcx> {
        ty::ParamEnv::reveal_all()
    }
}

impl<'tcx> LayoutOfHelpers<'tcx> for CodegenCx<'_, 'tcx> {
    type LayoutOfResult = TyAndLayout<'tcx>;

    #[inline]
    fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! {
        if let LayoutError::SizeOverflow(_) | LayoutError::ReferencesError(_) = err {
            self.tcx.dcx().emit_fatal(Spanned { span, node: err.into_diagnostic() })
        } else {
            self.tcx.dcx().emit_fatal(ssa_errors::FailedToGetLayout { span, ty, err })
        }
    }
}

impl<'tcx> FnAbiOfHelpers<'tcx> for CodegenCx<'_, 'tcx> {
    type FnAbiOfResult = &'tcx FnAbi<'tcx, Ty<'tcx>>;

    #[inline]
    fn handle_fn_abi_err(
        &self,
        err: FnAbiError<'tcx>,
        span: Span,
        fn_abi_request: FnAbiRequest<'tcx>,
    ) -> ! {
        if let FnAbiError::Layout(LayoutError::SizeOverflow(_)) = err {
            self.tcx.dcx().emit_fatal(Spanned { span, node: err })
        } else {
            match fn_abi_request {
                FnAbiRequest::OfFnPtr { sig, extra_args } => {
                    span_bug!(span, "`fn_abi_of_fn_ptr({sig}, {extra_args:?})` failed: {err:?}",);
                }
                FnAbiRequest::OfInstance { instance, extra_args } => {
                    span_bug!(
                        span,
                        "`fn_abi_of_instance({instance}, {extra_args:?})` failed: {err:?}",
                    );
                }
            }
        }
    }
}