rustc_builtin_macros/
asm.rs

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
use ast::token::IdentIsRaw;
use lint::BuiltinLintDiag;
use rustc_ast::AsmMacro;
use rustc_ast::ptr::P;
use rustc_ast::token::{self, Delimiter};
use rustc_ast::tokenstream::TokenStream;
use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
use rustc_errors::PResult;
use rustc_expand::base::*;
use rustc_index::bit_set::GrowableBitSet;
use rustc_parse::parser::Parser;
use rustc_session::lint;
use rustc_span::symbol::{Ident, Symbol, kw, sym};
use rustc_span::{ErrorGuaranteed, InnerSpan, Span};
use rustc_target::asm::InlineAsmArch;
use smallvec::smallvec;
use {rustc_ast as ast, rustc_parse_format as parse};

use crate::errors;
use crate::util::expr_to_spanned_string;

pub struct AsmArgs {
    pub templates: Vec<P<ast::Expr>>,
    pub operands: Vec<(ast::InlineAsmOperand, Span)>,
    named_args: FxIndexMap<Symbol, usize>,
    reg_args: GrowableBitSet<usize>,
    pub clobber_abis: Vec<(Symbol, Span)>,
    options: ast::InlineAsmOptions,
    pub options_spans: Vec<Span>,
}

/// Used for better error messages when operand types are used that are not
/// supported by the current macro (e.g. `in` or `out` for `global_asm!`)
///
/// returns
///
/// - `Ok(true)` if the current token matches the keyword, and was expected
/// - `Ok(false)` if the current token does not match the keyword
/// - `Err(_)` if the current token matches the keyword, but was not expected
fn eat_operand_keyword<'a>(
    p: &mut Parser<'a>,
    symbol: Symbol,
    asm_macro: AsmMacro,
) -> PResult<'a, bool> {
    if matches!(asm_macro, AsmMacro::Asm) {
        Ok(p.eat_keyword(symbol))
    } else {
        let span = p.token.span;
        if p.eat_keyword_noexpect(symbol) {
            // in gets printed as `r#in` otherwise
            let symbol = if symbol == kw::In { "in" } else { symbol.as_str() };
            Err(p.dcx().create_err(errors::AsmUnsupportedOperand {
                span,
                symbol,
                macro_name: asm_macro.macro_name(),
            }))
        } else {
            Ok(false)
        }
    }
}

fn parse_args<'a>(
    ecx: &ExtCtxt<'a>,
    sp: Span,
    tts: TokenStream,
    asm_macro: AsmMacro,
) -> PResult<'a, AsmArgs> {
    let mut p = ecx.new_parser_from_tts(tts);
    parse_asm_args(&mut p, sp, asm_macro)
}

// Primarily public for rustfmt consumption.
// Internal consumers should continue to leverage `expand_asm`/`expand__global_asm`
pub fn parse_asm_args<'a>(
    p: &mut Parser<'a>,
    sp: Span,
    asm_macro: AsmMacro,
) -> PResult<'a, AsmArgs> {
    let dcx = p.dcx();

    if p.token == token::Eof {
        return Err(dcx.create_err(errors::AsmRequiresTemplate { span: sp }));
    }

    let first_template = p.parse_expr()?;
    let mut args = AsmArgs {
        templates: vec![first_template],
        operands: vec![],
        named_args: Default::default(),
        reg_args: Default::default(),
        clobber_abis: Vec::new(),
        options: ast::InlineAsmOptions::empty(),
        options_spans: vec![],
    };

    let mut allow_templates = true;
    while p.token != token::Eof {
        if !p.eat(&token::Comma) {
            if allow_templates {
                // After a template string, we always expect *only* a comma...
                return Err(dcx.create_err(errors::AsmExpectedComma { span: p.token.span }));
            } else {
                // ...after that delegate to `expect` to also include the other expected tokens.
                return Err(p.expect(&token::Comma).err().unwrap());
            }
        }
        if p.token == token::Eof {
            break;
        } // accept trailing commas

        // Parse clobber_abi
        if p.eat_keyword(sym::clobber_abi) {
            parse_clobber_abi(p, &mut args)?;
            allow_templates = false;
            continue;
        }

        // Parse options
        if p.eat_keyword(sym::options) {
            parse_options(p, &mut args, asm_macro)?;
            allow_templates = false;
            continue;
        }

        let span_start = p.token.span;

        // Parse operand names
        let name = if p.token.is_ident() && p.look_ahead(1, |t| *t == token::Eq) {
            let (ident, _) = p.token.ident().unwrap();
            p.bump();
            p.expect(&token::Eq)?;
            allow_templates = false;
            Some(ident.name)
        } else {
            None
        };

        let mut explicit_reg = false;
        let op = if eat_operand_keyword(p, kw::In, asm_macro)? {
            let reg = parse_reg(p, &mut explicit_reg)?;
            if p.eat_keyword(kw::Underscore) {
                let err = dcx.create_err(errors::AsmUnderscoreInput { span: p.token.span });
                return Err(err);
            }
            let expr = p.parse_expr()?;
            ast::InlineAsmOperand::In { reg, expr }
        } else if eat_operand_keyword(p, sym::out, asm_macro)? {
            let reg = parse_reg(p, &mut explicit_reg)?;
            let expr = if p.eat_keyword(kw::Underscore) { None } else { Some(p.parse_expr()?) };
            ast::InlineAsmOperand::Out { reg, expr, late: false }
        } else if eat_operand_keyword(p, sym::lateout, asm_macro)? {
            let reg = parse_reg(p, &mut explicit_reg)?;
            let expr = if p.eat_keyword(kw::Underscore) { None } else { Some(p.parse_expr()?) };
            ast::InlineAsmOperand::Out { reg, expr, late: true }
        } else if eat_operand_keyword(p, sym::inout, asm_macro)? {
            let reg = parse_reg(p, &mut explicit_reg)?;
            if p.eat_keyword(kw::Underscore) {
                let err = dcx.create_err(errors::AsmUnderscoreInput { span: p.token.span });
                return Err(err);
            }
            let expr = p.parse_expr()?;
            if p.eat(&token::FatArrow) {
                let out_expr =
                    if p.eat_keyword(kw::Underscore) { None } else { Some(p.parse_expr()?) };
                ast::InlineAsmOperand::SplitInOut { reg, in_expr: expr, out_expr, late: false }
            } else {
                ast::InlineAsmOperand::InOut { reg, expr, late: false }
            }
        } else if eat_operand_keyword(p, sym::inlateout, asm_macro)? {
            let reg = parse_reg(p, &mut explicit_reg)?;
            if p.eat_keyword(kw::Underscore) {
                let err = dcx.create_err(errors::AsmUnderscoreInput { span: p.token.span });
                return Err(err);
            }
            let expr = p.parse_expr()?;
            if p.eat(&token::FatArrow) {
                let out_expr =
                    if p.eat_keyword(kw::Underscore) { None } else { Some(p.parse_expr()?) };
                ast::InlineAsmOperand::SplitInOut { reg, in_expr: expr, out_expr, late: true }
            } else {
                ast::InlineAsmOperand::InOut { reg, expr, late: true }
            }
        } else if eat_operand_keyword(p, sym::label, asm_macro)? {
            let block = p.parse_block()?;
            ast::InlineAsmOperand::Label { block }
        } else if p.eat_keyword(kw::Const) {
            let anon_const = p.parse_expr_anon_const()?;
            ast::InlineAsmOperand::Const { anon_const }
        } else if p.eat_keyword(sym::sym) {
            let expr = p.parse_expr()?;
            let ast::ExprKind::Path(qself, path) = &expr.kind else {
                let err = dcx.create_err(errors::AsmSymNoPath { span: expr.span });
                return Err(err);
            };
            let sym = ast::InlineAsmSym {
                id: ast::DUMMY_NODE_ID,
                qself: qself.clone(),
                path: path.clone(),
            };
            ast::InlineAsmOperand::Sym { sym }
        } else if allow_templates {
            let template = p.parse_expr()?;
            // If it can't possibly expand to a string, provide diagnostics here to include other
            // things it could have been.
            match template.kind {
                ast::ExprKind::Lit(token_lit)
                    if matches!(
                        token_lit.kind,
                        token::LitKind::Str | token::LitKind::StrRaw(_)
                    ) => {}
                ast::ExprKind::MacCall(..) => {}
                _ => {
                    let err = dcx.create_err(errors::AsmExpectedOther {
                        span: template.span,
                        is_inline_asm: matches!(asm_macro, AsmMacro::Asm),
                    });
                    return Err(err);
                }
            }
            args.templates.push(template);
            continue;
        } else {
            p.unexpected_any()?
        };

        allow_templates = false;
        let span = span_start.to(p.prev_token.span);
        let slot = args.operands.len();
        args.operands.push((op, span));

        // Validate the order of named, positional & explicit register operands and
        // clobber_abi/options. We do this at the end once we have the full span
        // of the argument available.
        if explicit_reg {
            if name.is_some() {
                dcx.emit_err(errors::AsmExplicitRegisterName { span });
            }
            args.reg_args.insert(slot);
        } else if let Some(name) = name {
            if let Some(&prev) = args.named_args.get(&name) {
                dcx.emit_err(errors::AsmDuplicateArg { span, name, prev: args.operands[prev].1 });
                continue;
            }
            args.named_args.insert(name, slot);
        } else if !args.named_args.is_empty() || !args.reg_args.is_empty() {
            let named = args.named_args.values().map(|p| args.operands[*p].1).collect();
            let explicit = args.reg_args.iter().map(|p| args.operands[p].1).collect();

            dcx.emit_err(errors::AsmPositionalAfter { span, named, explicit });
        }
    }

    if args.options.contains(ast::InlineAsmOptions::NOMEM)
        && args.options.contains(ast::InlineAsmOptions::READONLY)
    {
        let spans = args.options_spans.clone();
        dcx.emit_err(errors::AsmMutuallyExclusive { spans, opt1: "nomem", opt2: "readonly" });
    }
    if args.options.contains(ast::InlineAsmOptions::PURE)
        && args.options.contains(ast::InlineAsmOptions::NORETURN)
    {
        let spans = args.options_spans.clone();
        dcx.emit_err(errors::AsmMutuallyExclusive { spans, opt1: "pure", opt2: "noreturn" });
    }
    if args.options.contains(ast::InlineAsmOptions::PURE)
        && !args.options.intersects(ast::InlineAsmOptions::NOMEM | ast::InlineAsmOptions::READONLY)
    {
        let spans = args.options_spans.clone();
        dcx.emit_err(errors::AsmPureCombine { spans });
    }

    let mut have_real_output = false;
    let mut outputs_sp = vec![];
    let mut regclass_outputs = vec![];
    let mut labels_sp = vec![];
    for (op, op_sp) in &args.operands {
        match op {
            ast::InlineAsmOperand::Out { reg, expr, .. }
            | ast::InlineAsmOperand::SplitInOut { reg, out_expr: expr, .. } => {
                outputs_sp.push(*op_sp);
                have_real_output |= expr.is_some();
                if let ast::InlineAsmRegOrRegClass::RegClass(_) = reg {
                    regclass_outputs.push(*op_sp);
                }
            }
            ast::InlineAsmOperand::InOut { reg, .. } => {
                outputs_sp.push(*op_sp);
                have_real_output = true;
                if let ast::InlineAsmRegOrRegClass::RegClass(_) = reg {
                    regclass_outputs.push(*op_sp);
                }
            }
            ast::InlineAsmOperand::Label { .. } => {
                labels_sp.push(*op_sp);
            }
            _ => {}
        }
    }
    if args.options.contains(ast::InlineAsmOptions::PURE) && !have_real_output {
        dcx.emit_err(errors::AsmPureNoOutput { spans: args.options_spans.clone() });
    }
    if args.options.contains(ast::InlineAsmOptions::NORETURN) && !outputs_sp.is_empty() {
        let err = dcx.create_err(errors::AsmNoReturn { outputs_sp });
        // Bail out now since this is likely to confuse MIR
        return Err(err);
    }
    if args.options.contains(ast::InlineAsmOptions::MAY_UNWIND) && !labels_sp.is_empty() {
        dcx.emit_err(errors::AsmMayUnwind { labels_sp });
    }

    if !args.clobber_abis.is_empty() {
        match asm_macro {
            AsmMacro::GlobalAsm | AsmMacro::NakedAsm => {
                let err = dcx.create_err(errors::AsmUnsupportedClobberAbi {
                    spans: args.clobber_abis.iter().map(|(_, span)| *span).collect(),
                    macro_name: asm_macro.macro_name(),
                });

                // Bail out now since this is likely to confuse later stages
                return Err(err);
            }
            AsmMacro::Asm => {
                if !regclass_outputs.is_empty() {
                    dcx.emit_err(errors::AsmClobberNoReg {
                        spans: regclass_outputs,
                        clobbers: args.clobber_abis.iter().map(|(_, span)| *span).collect(),
                    });
                }
            }
        }
    }

    Ok(args)
}

/// Report a duplicate option error.
///
/// This function must be called immediately after the option token is parsed.
/// Otherwise, the suggestion will be incorrect.
fn err_duplicate_option(p: &Parser<'_>, symbol: Symbol, span: Span) {
    // Tool-only output
    let full_span = if p.token == token::Comma { span.to(p.token.span) } else { span };
    p.dcx().emit_err(errors::AsmOptAlreadyprovided { span, symbol, full_span });
}

/// Report an invalid option error.
///
/// This function must be called immediately after the option token is parsed.
/// Otherwise, the suggestion will be incorrect.
fn err_unsupported_option(p: &Parser<'_>, asm_macro: AsmMacro, symbol: Symbol, span: Span) {
    // Tool-only output
    let full_span = if p.token == token::Comma { span.to(p.token.span) } else { span };
    p.dcx().emit_err(errors::AsmUnsupportedOption {
        span,
        symbol,
        full_span,
        macro_name: asm_macro.macro_name(),
    });
}

/// Try to set the provided option in the provided `AsmArgs`.
/// If it is already set, report a duplicate option error.
///
/// This function must be called immediately after the option token is parsed.
/// Otherwise, the error will not point to the correct spot.
fn try_set_option<'a>(
    p: &Parser<'a>,
    args: &mut AsmArgs,
    asm_macro: AsmMacro,
    symbol: Symbol,
    option: ast::InlineAsmOptions,
) {
    if !asm_macro.is_supported_option(option) {
        err_unsupported_option(p, asm_macro, symbol, p.prev_token.span);
    } else if args.options.contains(option) {
        err_duplicate_option(p, symbol, p.prev_token.span);
    } else {
        args.options |= option;
    }
}

fn parse_options<'a>(
    p: &mut Parser<'a>,
    args: &mut AsmArgs,
    asm_macro: AsmMacro,
) -> PResult<'a, ()> {
    let span_start = p.prev_token.span;

    p.expect(&token::OpenDelim(Delimiter::Parenthesis))?;

    while !p.eat(&token::CloseDelim(Delimiter::Parenthesis)) {
        const OPTIONS: [(Symbol, ast::InlineAsmOptions); ast::InlineAsmOptions::COUNT] = [
            (sym::pure, ast::InlineAsmOptions::PURE),
            (sym::nomem, ast::InlineAsmOptions::NOMEM),
            (sym::readonly, ast::InlineAsmOptions::READONLY),
            (sym::preserves_flags, ast::InlineAsmOptions::PRESERVES_FLAGS),
            (sym::noreturn, ast::InlineAsmOptions::NORETURN),
            (sym::nostack, ast::InlineAsmOptions::NOSTACK),
            (sym::may_unwind, ast::InlineAsmOptions::MAY_UNWIND),
            (sym::att_syntax, ast::InlineAsmOptions::ATT_SYNTAX),
            (kw::Raw, ast::InlineAsmOptions::RAW),
        ];

        'blk: {
            for (symbol, option) in OPTIONS {
                let kw_matched = if asm_macro.is_supported_option(option) {
                    p.eat_keyword(symbol)
                } else {
                    p.eat_keyword_noexpect(symbol)
                };

                if kw_matched {
                    try_set_option(p, args, asm_macro, symbol, option);
                    break 'blk;
                }
            }

            return p.unexpected();
        }

        // Allow trailing commas
        if p.eat(&token::CloseDelim(Delimiter::Parenthesis)) {
            break;
        }
        p.expect(&token::Comma)?;
    }

    let new_span = span_start.to(p.prev_token.span);
    args.options_spans.push(new_span);

    Ok(())
}

fn parse_clobber_abi<'a>(p: &mut Parser<'a>, args: &mut AsmArgs) -> PResult<'a, ()> {
    let span_start = p.prev_token.span;

    p.expect(&token::OpenDelim(Delimiter::Parenthesis))?;

    if p.eat(&token::CloseDelim(Delimiter::Parenthesis)) {
        return Err(p.dcx().create_err(errors::NonABI { span: p.token.span }));
    }

    let mut new_abis = Vec::new();
    while !p.eat(&token::CloseDelim(Delimiter::Parenthesis)) {
        match p.parse_str_lit() {
            Ok(str_lit) => {
                new_abis.push((str_lit.symbol_unescaped, str_lit.span));
            }
            Err(opt_lit) => {
                let span = opt_lit.map_or(p.token.span, |lit| lit.span);
                return Err(p.dcx().create_err(errors::AsmExpectedStringLiteral { span }));
            }
        };

        // Allow trailing commas
        if p.eat(&token::CloseDelim(Delimiter::Parenthesis)) {
            break;
        }
        p.expect(&token::Comma)?;
    }

    let full_span = span_start.to(p.prev_token.span);

    match &new_abis[..] {
        // should have errored above during parsing
        [] => unreachable!(),
        [(abi, _span)] => args.clobber_abis.push((*abi, full_span)),
        abis => {
            for (abi, span) in abis {
                args.clobber_abis.push((*abi, *span));
            }
        }
    }

    Ok(())
}

fn parse_reg<'a>(
    p: &mut Parser<'a>,
    explicit_reg: &mut bool,
) -> PResult<'a, ast::InlineAsmRegOrRegClass> {
    p.expect(&token::OpenDelim(Delimiter::Parenthesis))?;
    let result = match p.token.uninterpolate().kind {
        token::Ident(name, IdentIsRaw::No) => ast::InlineAsmRegOrRegClass::RegClass(name),
        token::Literal(token::Lit { kind: token::LitKind::Str, symbol, suffix: _ }) => {
            *explicit_reg = true;
            ast::InlineAsmRegOrRegClass::Reg(symbol)
        }
        _ => {
            return Err(p.dcx().create_err(errors::ExpectedRegisterClassOrExplicitRegister {
                span: p.token.span,
            }));
        }
    };
    p.bump();
    p.expect(&token::CloseDelim(Delimiter::Parenthesis))?;
    Ok(result)
}

fn expand_preparsed_asm(
    ecx: &mut ExtCtxt<'_>,
    asm_macro: AsmMacro,
    args: AsmArgs,
) -> ExpandResult<Result<ast::InlineAsm, ErrorGuaranteed>, ()> {
    let mut template = vec![];
    // Register operands are implicitly used since they are not allowed to be
    // referenced in the template string.
    let mut used = vec![false; args.operands.len()];
    for pos in args.reg_args.iter() {
        used[pos] = true;
    }
    let named_pos: FxHashMap<usize, Symbol> =
        args.named_args.iter().map(|(&sym, &idx)| (idx, sym)).collect();
    let mut line_spans = Vec::with_capacity(args.templates.len());
    let mut curarg = 0;

    let mut template_strs = Vec::with_capacity(args.templates.len());

    for (i, template_expr) in args.templates.into_iter().enumerate() {
        if i != 0 {
            template.push(ast::InlineAsmTemplatePiece::String("\n".into()));
        }

        let msg = "asm template must be a string literal";
        let template_sp = template_expr.span;
        let template_is_mac_call = matches!(template_expr.kind, ast::ExprKind::MacCall(_));
        let (template_str, template_style, template_span) = {
            let ExpandResult::Ready(mac) = expr_to_spanned_string(ecx, template_expr, msg) else {
                return ExpandResult::Retry(());
            };
            match mac {
                Ok(template_part) => template_part,
                Err(err) => {
                    return ExpandResult::Ready(Err(match err {
                        Ok((err, _)) => err.emit(),
                        Err(guar) => guar,
                    }));
                }
            }
        };

        let str_style = match template_style {
            ast::StrStyle::Cooked => None,
            ast::StrStyle::Raw(raw) => Some(raw as usize),
        };

        let template_snippet = ecx.source_map().span_to_snippet(template_sp).ok();
        template_strs.push((
            template_str,
            template_snippet.as_deref().map(Symbol::intern),
            template_sp,
        ));
        let template_str = template_str.as_str();

        if let Some(InlineAsmArch::X86 | InlineAsmArch::X86_64) = ecx.sess.asm_arch {
            let find_span = |needle: &str| -> Span {
                if let Some(snippet) = &template_snippet {
                    if let Some(pos) = snippet.find(needle) {
                        let end = pos
                            + snippet[pos..]
                                .find(|c| matches!(c, '\n' | ';' | '\\' | '"'))
                                .unwrap_or(snippet[pos..].len() - 1);
                        let inner = InnerSpan::new(pos, end);
                        return template_sp.from_inner(inner);
                    }
                }
                template_sp
            };

            if template_str.contains(".intel_syntax") {
                ecx.psess().buffer_lint(
                    lint::builtin::BAD_ASM_STYLE,
                    find_span(".intel_syntax"),
                    ecx.current_expansion.lint_node_id,
                    BuiltinLintDiag::AvoidUsingIntelSyntax,
                );
            }
            if template_str.contains(".att_syntax") {
                ecx.psess().buffer_lint(
                    lint::builtin::BAD_ASM_STYLE,
                    find_span(".att_syntax"),
                    ecx.current_expansion.lint_node_id,
                    BuiltinLintDiag::AvoidUsingAttSyntax,
                );
            }
        }

        // Don't treat raw asm as a format string.
        if args.options.contains(ast::InlineAsmOptions::RAW) {
            template.push(ast::InlineAsmTemplatePiece::String(template_str.to_string().into()));
            let template_num_lines = 1 + template_str.matches('\n').count();
            line_spans.extend(std::iter::repeat(template_sp).take(template_num_lines));
            continue;
        }

        let mut parser = parse::Parser::new(
            template_str,
            str_style,
            template_snippet,
            false,
            parse::ParseMode::InlineAsm,
        );
        parser.curarg = curarg;

        let mut unverified_pieces = Vec::new();
        while let Some(piece) = parser.next() {
            if !parser.errors.is_empty() {
                break;
            } else {
                unverified_pieces.push(piece);
            }
        }

        if !parser.errors.is_empty() {
            let err = parser.errors.remove(0);
            let err_sp = if template_is_mac_call {
                // If the template is a macro call we can't reliably point to the error's
                // span so just use the template's span as the error span (fixes #129503)
                template_span
            } else {
                template_span.from_inner(InnerSpan::new(err.span.start, err.span.end))
            };

            let msg = format!("invalid asm template string: {}", err.description);
            let mut e = ecx.dcx().struct_span_err(err_sp, msg);
            e.span_label(err_sp, err.label + " in asm template string");
            if let Some(note) = err.note {
                e.note(note);
            }
            if let Some((label, span)) = err.secondary_label {
                let err_sp = template_span.from_inner(InnerSpan::new(span.start, span.end));
                e.span_label(err_sp, label);
            }
            let guar = e.emit();
            return ExpandResult::Ready(Err(guar));
        }

        curarg = parser.curarg;

        let mut arg_spans = parser
            .arg_places
            .iter()
            .map(|span| template_span.from_inner(InnerSpan::new(span.start, span.end)));
        for piece in unverified_pieces {
            match piece {
                parse::Piece::String(s) => {
                    template.push(ast::InlineAsmTemplatePiece::String(s.to_string().into()))
                }
                parse::Piece::NextArgument(arg) => {
                    let span = arg_spans.next().unwrap_or(template_sp);

                    let operand_idx = match arg.position {
                        parse::ArgumentIs(idx) | parse::ArgumentImplicitlyIs(idx) => {
                            if idx >= args.operands.len()
                                || named_pos.contains_key(&idx)
                                || args.reg_args.contains(idx)
                            {
                                let msg = format!("invalid reference to argument at index {idx}");
                                let mut err = ecx.dcx().struct_span_err(span, msg);
                                err.span_label(span, "from here");

                                let positional_args = args.operands.len()
                                    - args.named_args.len()
                                    - args.reg_args.len();
                                let positional = if positional_args != args.operands.len() {
                                    "positional "
                                } else {
                                    ""
                                };
                                let msg = match positional_args {
                                    0 => format!("no {positional}arguments were given"),
                                    1 => format!("there is 1 {positional}argument"),
                                    x => format!("there are {x} {positional}arguments"),
                                };
                                err.note(msg);

                                if named_pos.contains_key(&idx) {
                                    err.span_label(args.operands[idx].1, "named argument");
                                    err.span_note(
                                        args.operands[idx].1,
                                        "named arguments cannot be referenced by position",
                                    );
                                } else if args.reg_args.contains(idx) {
                                    err.span_label(
                                        args.operands[idx].1,
                                        "explicit register argument",
                                    );
                                    err.span_note(
                                        args.operands[idx].1,
                                        "explicit register arguments cannot be used in the asm template",
                                    );
                                    err.span_help(
                                        args.operands[idx].1,
                                        "use the register name directly in the assembly code",
                                    );
                                }
                                err.emit();
                                None
                            } else {
                                Some(idx)
                            }
                        }
                        parse::ArgumentNamed(name) => {
                            match args.named_args.get(&Symbol::intern(name)) {
                                Some(&idx) => Some(idx),
                                None => {
                                    let span = arg.position_span;
                                    ecx.dcx()
                                        .create_err(errors::AsmNoMatchedArgumentName {
                                            name: name.to_owned(),
                                            span: template_span
                                                .from_inner(InnerSpan::new(span.start, span.end)),
                                        })
                                        .emit();
                                    None
                                }
                            }
                        }
                    };

                    let mut chars = arg.format.ty.chars();
                    let mut modifier = chars.next();
                    if chars.next().is_some() {
                        let span = arg
                            .format
                            .ty_span
                            .map(|sp| template_sp.from_inner(InnerSpan::new(sp.start, sp.end)))
                            .unwrap_or(template_sp);
                        ecx.dcx().emit_err(errors::AsmModifierInvalid { span });
                        modifier = None;
                    }

                    if let Some(operand_idx) = operand_idx {
                        used[operand_idx] = true;
                        template.push(ast::InlineAsmTemplatePiece::Placeholder {
                            operand_idx,
                            modifier,
                            span,
                        });
                    }
                }
            }
        }

        if parser.line_spans.is_empty() {
            let template_num_lines = 1 + template_str.matches('\n').count();
            line_spans.extend(std::iter::repeat(template_sp).take(template_num_lines));
        } else {
            line_spans.extend(
                parser
                    .line_spans
                    .iter()
                    .map(|span| template_span.from_inner(InnerSpan::new(span.start, span.end))),
            );
        };
    }

    let mut unused_operands = vec![];
    let mut help_str = String::new();
    for (idx, used) in used.into_iter().enumerate() {
        if !used {
            let msg = if let Some(sym) = named_pos.get(&idx) {
                help_str.push_str(&format!(" {{{}}}", sym));
                "named argument never used"
            } else {
                help_str.push_str(&format!(" {{{}}}", idx));
                "argument never used"
            };
            unused_operands.push((args.operands[idx].1, msg));
        }
    }
    match unused_operands[..] {
        [] => {}
        [(sp, msg)] => {
            ecx.dcx()
                .struct_span_err(sp, msg)
                .with_span_label(sp, msg)
                .with_help(format!(
                    "if this argument is intentionally unused, \
                     consider using it in an asm comment: `\"/*{help_str} */\"`"
                ))
                .emit();
        }
        _ => {
            let mut err = ecx.dcx().struct_span_err(
                unused_operands.iter().map(|&(sp, _)| sp).collect::<Vec<Span>>(),
                "multiple unused asm arguments",
            );
            for (sp, msg) in unused_operands {
                err.span_label(sp, msg);
            }
            err.help(format!(
                "if these arguments are intentionally unused, \
                 consider using them in an asm comment: `\"/*{help_str} */\"`"
            ));
            err.emit();
        }
    }

    ExpandResult::Ready(Ok(ast::InlineAsm {
        asm_macro,
        template,
        template_strs: template_strs.into_boxed_slice(),
        operands: args.operands,
        clobber_abis: args.clobber_abis,
        options: args.options,
        line_spans,
    }))
}

pub(super) fn expand_asm<'cx>(
    ecx: &'cx mut ExtCtxt<'_>,
    sp: Span,
    tts: TokenStream,
) -> MacroExpanderResult<'cx> {
    ExpandResult::Ready(match parse_args(ecx, sp, tts, AsmMacro::Asm) {
        Ok(args) => {
            let ExpandResult::Ready(mac) = expand_preparsed_asm(ecx, AsmMacro::Asm, args) else {
                return ExpandResult::Retry(());
            };
            let expr = match mac {
                Ok(inline_asm) => P(ast::Expr {
                    id: ast::DUMMY_NODE_ID,
                    kind: ast::ExprKind::InlineAsm(P(inline_asm)),
                    span: sp,
                    attrs: ast::AttrVec::new(),
                    tokens: None,
                }),
                Err(guar) => DummyResult::raw_expr(sp, Some(guar)),
            };
            MacEager::expr(expr)
        }
        Err(err) => {
            let guar = err.emit();
            DummyResult::any(sp, guar)
        }
    })
}

pub(super) fn expand_naked_asm<'cx>(
    ecx: &'cx mut ExtCtxt<'_>,
    sp: Span,
    tts: TokenStream,
) -> MacroExpanderResult<'cx> {
    ExpandResult::Ready(match parse_args(ecx, sp, tts, AsmMacro::NakedAsm) {
        Ok(args) => {
            let ExpandResult::Ready(mac) = expand_preparsed_asm(ecx, AsmMacro::NakedAsm, args)
            else {
                return ExpandResult::Retry(());
            };
            let expr = match mac {
                Ok(inline_asm) => P(ast::Expr {
                    id: ast::DUMMY_NODE_ID,
                    kind: ast::ExprKind::InlineAsm(P(inline_asm)),
                    span: sp,
                    attrs: ast::AttrVec::new(),
                    tokens: None,
                }),
                Err(guar) => DummyResult::raw_expr(sp, Some(guar)),
            };
            MacEager::expr(expr)
        }
        Err(err) => {
            let guar = err.emit();
            DummyResult::any(sp, guar)
        }
    })
}

pub(super) fn expand_global_asm<'cx>(
    ecx: &'cx mut ExtCtxt<'_>,
    sp: Span,
    tts: TokenStream,
) -> MacroExpanderResult<'cx> {
    ExpandResult::Ready(match parse_args(ecx, sp, tts, AsmMacro::GlobalAsm) {
        Ok(args) => {
            let ExpandResult::Ready(mac) = expand_preparsed_asm(ecx, AsmMacro::GlobalAsm, args)
            else {
                return ExpandResult::Retry(());
            };
            match mac {
                Ok(inline_asm) => MacEager::items(smallvec![P(ast::Item {
                    ident: Ident::empty(),
                    attrs: ast::AttrVec::new(),
                    id: ast::DUMMY_NODE_ID,
                    kind: ast::ItemKind::GlobalAsm(Box::new(inline_asm)),
                    vis: ast::Visibility {
                        span: sp.shrink_to_lo(),
                        kind: ast::VisibilityKind::Inherited,
                        tokens: None,
                    },
                    span: sp,
                    tokens: None,
                })]),
                Err(guar) => DummyResult::any(sp, guar),
            }
        }
        Err(err) => {
            let guar = err.emit();
            DummyResult::any(sp, guar)
        }
    })
}