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
|
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Identify mismatches between assembly files and Go func declarations.
package main
import (
"bytes"
"fmt"
"go/ast"
"go/build"
"go/token"
"go/types"
"regexp"
"strconv"
"strings"
)
// 'kind' is a kind of assembly variable.
// The kinds 1, 2, 4, 8 stand for values of that size.
type asmKind int
// These special kinds are not valid sizes.
const (
asmString asmKind = 100 + iota
asmSlice
asmArray
asmInterface
asmEmptyInterface
asmStruct
asmComplex
)
// An asmArch describes assembly parameters for an architecture
type asmArch struct {
name string
bigEndian bool
stack string
lr bool
// calculated during initialization
sizes types.Sizes
intSize int
ptrSize int
maxAlign int
}
// An asmFunc describes the expected variables for a function on a given architecture.
type asmFunc struct {
arch *asmArch
size int // size of all arguments
vars map[string]*asmVar
varByOffset map[int]*asmVar
}
// An asmVar describes a single assembly variable.
type asmVar struct {
name string
kind asmKind
typ string
off int
size int
inner []*asmVar
}
var (
asmArch386 = asmArch{name: "386", bigEndian: false, stack: "SP", lr: false}
asmArchArm = asmArch{name: "arm", bigEndian: false, stack: "R13", lr: true}
asmArchArm64 = asmArch{name: "arm64", bigEndian: false, stack: "RSP", lr: true}
asmArchAmd64 = asmArch{name: "amd64", bigEndian: false, stack: "SP", lr: false}
asmArchAmd64p32 = asmArch{name: "amd64p32", bigEndian: false, stack: "SP", lr: false}
asmArchMips = asmArch{name: "mips", bigEndian: true, stack: "R29", lr: true}
asmArchMipsLE = asmArch{name: "mipsle", bigEndian: false, stack: "R29", lr: true}
asmArchMips64 = asmArch{name: "mips64", bigEndian: true, stack: "R29", lr: true}
asmArchMips64LE = asmArch{name: "mips64le", bigEndian: false, stack: "R29", lr: true}
asmArchPpc64 = asmArch{name: "ppc64", bigEndian: true, stack: "R1", lr: true}
asmArchPpc64LE = asmArch{name: "ppc64le", bigEndian: false, stack: "R1", lr: true}
asmArchS390X = asmArch{name: "s390x", bigEndian: true, stack: "R15", lr: true}
arches = []*asmArch{
&asmArch386,
&asmArchArm,
&asmArchArm64,
&asmArchAmd64,
&asmArchAmd64p32,
&asmArchMips,
&asmArchMipsLE,
&asmArchMips64,
&asmArchMips64LE,
&asmArchPpc64,
&asmArchPpc64LE,
&asmArchS390X,
}
)
func init() {
for _, arch := range arches {
arch.sizes = types.SizesFor("gc", arch.name)
if arch.sizes == nil {
panic("missing SizesFor for gc/" + arch.name)
}
arch.intSize = int(arch.sizes.Sizeof(types.Typ[types.Int]))
arch.ptrSize = int(arch.sizes.Sizeof(types.Typ[types.UnsafePointer]))
arch.maxAlign = int(arch.sizes.Alignof(types.Typ[types.Int64]))
}
}
var (
re = regexp.MustCompile
asmPlusBuild = re(`//\s+\+build\s+([^\n]+)`)
asmTEXT = re(`\bTEXT\b(.*)·([^\(]+)\(SB\)(?:\s*,\s*([0-9A-Z|+()]+))?(?:\s*,\s*\$(-?[0-9]+)(?:-([0-9]+))?)?`)
asmDATA = re(`\b(DATA|GLOBL)\b`)
asmNamedFP = re(`([a-zA-Z0-9_\xFF-\x{10FFFF}]+)(?:\+([0-9]+))\(FP\)`)
asmUnnamedFP = re(`[^+\-0-9](([0-9]+)\(FP\))`)
asmSP = re(`[^+\-0-9](([0-9]+)\(([A-Z0-9]+)\))`)
asmOpcode = re(`^\s*(?:[A-Z0-9a-z_]+:)?\s*([A-Z]+)\s*([^,]*)(?:,\s*(.*))?`)
ppc64Suff = re(`([BHWD])(ZU|Z|U|BR)?$`)
)
func asmCheck(pkg *Package) {
if !vet("asmdecl") {
return
}
// No work if no assembly files.
if !pkg.hasFileWithSuffix(".s") {
return
}
// Gather declarations. knownFunc[name][arch] is func description.
knownFunc := make(map[string]map[string]*asmFunc)
for _, f := range pkg.files {
if f.file != nil {
for _, decl := range f.file.Decls {
if decl, ok := decl.(*ast.FuncDecl); ok && decl.Body == nil {
knownFunc[decl.Name.Name] = f.asmParseDecl(decl)
}
}
}
}
Files:
for _, f := range pkg.files {
if !strings.HasSuffix(f.name, ".s") {
continue
}
Println("Checking file", f.name)
// Determine architecture from file name if possible.
var arch string
var archDef *asmArch
for _, a := range arches {
if strings.HasSuffix(f.name, "_"+a.name+".s") {
arch = a.name
archDef = a
break
}
}
lines := strings.SplitAfter(string(f.content), "\n")
var (
fn *asmFunc
fnName string
localSize, argSize int
wroteSP bool
haveRetArg bool
retLine []int
)
flushRet := func() {
if fn != nil && fn.vars["ret"] != nil && !haveRetArg && len(retLine) > 0 {
v := fn.vars["ret"]
for _, line := range retLine {
f.Badf(token.NoPos, "%s:%d: [%s] %s: RET without writing to %d-byte ret+%d(FP)", f.name, line, arch, fnName, v.size, v.off)
}
}
retLine = nil
}
for lineno, line := range lines {
lineno++
badf := func(format string, args ...interface{}) {
f.Badf(token.NoPos, "%s:%d: [%s] %s: %s", f.name, lineno, arch, fnName, fmt.Sprintf(format, args...))
}
if arch == "" {
// Determine architecture from +build line if possible.
if m := asmPlusBuild.FindStringSubmatch(line); m != nil {
// There can be multiple architectures in a single +build line,
// so accumulate them all and then prefer the one that
// matches build.Default.GOARCH.
var archCandidates []*asmArch
for _, fld := range strings.Fields(m[1]) {
for _, a := range arches {
if a.name == fld {
archCandidates = append(archCandidates, a)
}
}
}
for _, a := range archCandidates {
if a.name == build.Default.GOARCH {
archCandidates = []*asmArch{a}
break
}
}
if len(archCandidates) > 0 {
arch = archCandidates[0].name
archDef = archCandidates[0]
}
}
}
if m := asmTEXT.FindStringSubmatch(line); m != nil {
flushRet()
if arch == "" {
// Arch not specified by filename or build tags.
// Fall back to build.Default.GOARCH.
for _, a := range arches {
if a.name == build.Default.GOARCH {
arch = a.name
archDef = a
break
}
}
if arch == "" {
f.Warnf(token.NoPos, "%s: cannot determine architecture for assembly file", f.name)
continue Files
}
}
fnName = m[2]
if pkgName := strings.TrimSpace(m[1]); pkgName != "" {
pathParts := strings.Split(pkgName, "∕")
pkgName = pathParts[len(pathParts)-1]
if pkgName != f.pkg.path {
f.Warnf(token.NoPos, "%s:%d: [%s] cannot check cross-package assembly function: %s is in package %s", f.name, lineno, arch, fnName, pkgName)
fn = nil
fnName = ""
continue
}
}
fn = knownFunc[fnName][arch]
if fn != nil {
size, _ := strconv.Atoi(m[5])
flag := m[3]
if size != fn.size && (flag != "7" && !strings.Contains(flag, "NOSPLIT") || size != 0) {
badf("wrong argument size %d; expected $...-%d", size, fn.size)
}
}
localSize, _ = strconv.Atoi(m[4])
localSize += archDef.intSize
if archDef.lr {
// Account for caller's saved LR
localSize += archDef.intSize
}
argSize, _ = strconv.Atoi(m[5])
if fn == nil && !strings.Contains(fnName, "<>") {
badf("function %s missing Go declaration", fnName)
}
wroteSP = false
haveRetArg = false
continue
} else if strings.Contains(line, "TEXT") && strings.Contains(line, "SB") {
// function, but not visible from Go (didn't match asmTEXT), so stop checking
flushRet()
fn = nil
fnName = ""
continue
}
if strings.Contains(line, "RET") {
retLine = append(retLine, lineno)
}
if fnName == "" {
continue
}
if asmDATA.FindStringSubmatch(line) != nil {
fn = nil
}
if archDef == nil {
continue
}
if strings.Contains(line, ", "+archDef.stack) || strings.Contains(line, ",\t"+archDef.stack) {
wroteSP = true
continue
}
for _, m := range asmSP.FindAllStringSubmatch(line, -1) {
if m[3] != archDef.stack || wroteSP {
continue
}
off := 0
if m[1] != "" {
off, _ = strconv.Atoi(m[2])
}
if off >= localSize {
if fn != nil {
v := fn.varByOffset[off-localSize]
if v != nil {
badf("%s should be %s+%d(FP)", m[1], v.name, off-localSize)
continue
}
}
if off >= localSize+argSize {
badf("use of %s points beyond argument frame", m[1])
continue
}
badf("use of %s to access argument frame", m[1])
}
}
if fn == nil {
continue
}
for _, m := range asmUnnamedFP.FindAllStringSubmatch(line, -1) {
off, _ := strconv.Atoi(m[2])
v := fn.varByOffset[off]
if v != nil {
badf("use of unnamed argument %s; offset %d is %s+%d(FP)", m[1], off, v.name, v.off)
} else {
badf("use of unnamed argument %s", m[1])
}
}
for _, m := range asmNamedFP.FindAllStringSubmatch(line, -1) {
name := m[1]
off := 0
if m[2] != "" {
off, _ = strconv.Atoi(m[2])
}
if name == "ret" || strings.HasPrefix(name, "ret_") {
haveRetArg = true
}
v := fn.vars[name]
if v == nil {
// Allow argframe+0(FP).
if name == "argframe" && off == 0 {
continue
}
v = fn.varByOffset[off]
if v != nil {
badf("unknown variable %s; offset %d is %s+%d(FP)", name, off, v.name, v.off)
} else {
badf("unknown variable %s", name)
}
continue
}
asmCheckVar(badf, fn, line, m[0], off, v)
}
}
flushRet()
}
}
func asmKindForType(t types.Type, size int) asmKind {
switch t := t.Underlying().(type) {
case *types.Basic:
switch t.Kind() {
case types.String:
return asmString
case types.Complex64, types.Complex128:
return asmComplex
}
return asmKind(size)
case *types.Pointer, *types.Chan, *types.Map, *types.Signature:
return asmKind(size)
case *types.Struct:
return asmStruct
case *types.Interface:
if t.Empty() {
return asmEmptyInterface
}
return asmInterface
case *types.Array:
return asmArray
case *types.Slice:
return asmSlice
}
panic("unreachable")
}
// A component is an assembly-addressable component of a composite type,
// or a composite type itself.
type component struct {
size int
offset int
kind asmKind
typ string
suffix string // Such as _base for string base, _0_lo for lo half of first element of [1]uint64 on 32 bit machine.
outer string // The suffix for immediately containing composite type.
}
func newComponent(suffix string, kind asmKind, typ string, offset, size int, outer string) component {
return component{suffix: suffix, kind: kind, typ: typ, offset: offset, size: size, outer: outer}
}
// componentsOfType generates a list of components of type t.
// For example, given string, the components are the string itself, the base, and the length.
func componentsOfType(arch *asmArch, t types.Type) []component {
return appendComponentsRecursive(arch, t, nil, "", 0)
}
// appendComponentsRecursive implements componentsOfType.
// Recursion is required to correct handle structs and arrays,
// which can contain arbitrary other types.
func appendComponentsRecursive(arch *asmArch, t types.Type, cc []component, suffix string, off int) []component {
s := t.String()
size := int(arch.sizes.Sizeof(t))
kind := asmKindForType(t, size)
cc = append(cc, newComponent(suffix, kind, s, off, size, suffix))
switch kind {
case 8:
if arch.ptrSize == 4 {
w1, w2 := "lo", "hi"
if arch.bigEndian {
w1, w2 = w2, w1
}
cc = append(cc, newComponent(suffix+"_"+w1, 4, "half "+s, off, 4, suffix))
cc = append(cc, newComponent(suffix+"_"+w2, 4, "half "+s, off+4, 4, suffix))
}
case asmEmptyInterface:
cc = append(cc, newComponent(suffix+"_type", asmKind(arch.ptrSize), "interface type", off, arch.ptrSize, suffix))
cc = append(cc, newComponent(suffix+"_data", asmKind(arch.ptrSize), "interface data", off+arch.ptrSize, arch.ptrSize, suffix))
case asmInterface:
cc = append(cc, newComponent(suffix+"_itable", asmKind(arch.ptrSize), "interface itable", off, arch.ptrSize, suffix))
cc = append(cc, newComponent(suffix+"_data", asmKind(arch.ptrSize), "interface data", off+arch.ptrSize, arch.ptrSize, suffix))
case asmSlice:
cc = append(cc, newComponent(suffix+"_base", asmKind(arch.ptrSize), "slice base", off, arch.ptrSize, suffix))
cc = append(cc, newComponent(suffix+"_len", asmKind(arch.intSize), "slice len", off+arch.ptrSize, arch.intSize, suffix))
cc = append(cc, newComponent(suffix+"_cap", asmKind(arch.intSize), "slice cap", off+arch.ptrSize+arch.intSize, arch.intSize, suffix))
case asmString:
cc = append(cc, newComponent(suffix+"_base", asmKind(arch.ptrSize), "string base", off, arch.ptrSize, suffix))
cc = append(cc, newComponent(suffix+"_len", asmKind(arch.intSize), "string len", off+arch.ptrSize, arch.intSize, suffix))
case asmComplex:
fsize := size / 2
cc = append(cc, newComponent(suffix+"_real", asmKind(fsize), fmt.Sprintf("real(complex%d)", size*8), off, fsize, suffix))
cc = append(cc, newComponent(suffix+"_imag", asmKind(fsize), fmt.Sprintf("imag(complex%d)", size*8), off+fsize, fsize, suffix))
case asmStruct:
tu := t.Underlying().(*types.Struct)
fields := make([]*types.Var, tu.NumFields())
for i := 0; i < tu.NumFields(); i++ {
fields[i] = tu.Field(i)
}
offsets := arch.sizes.Offsetsof(fields)
for i, f := range fields {
cc = appendComponentsRecursive(arch, f.Type(), cc, suffix+"_"+f.Name(), off+int(offsets[i]))
}
case asmArray:
tu := t.Underlying().(*types.Array)
elem := tu.Elem()
// Calculate offset of each element array.
fields := []*types.Var{
types.NewVar(token.NoPos, nil, "fake0", elem),
types.NewVar(token.NoPos, nil, "fake1", elem),
}
offsets := arch.sizes.Offsetsof(fields)
elemoff := int(offsets[1])
for i := 0; i < int(tu.Len()); i++ {
cc = appendComponentsRecursive(arch, elem, cc, suffix+"_"+strconv.Itoa(i), i*elemoff)
}
}
return cc
}
// asmParseDecl parses a function decl for expected assembly variables.
func (f *File) asmParseDecl(decl *ast.FuncDecl) map[string]*asmFunc {
var (
arch *asmArch
fn *asmFunc
offset int
)
// addParams adds asmVars for each of the parameters in list.
// isret indicates whether the list are the arguments or the return values.
addParams := func(list []*ast.Field, isret bool) {
argnum := 0
for _, fld := range list {
t := f.pkg.types[fld.Type].Type
align := int(arch.sizes.Alignof(t))
size := int(arch.sizes.Sizeof(t))
offset += -offset & (align - 1)
cc := componentsOfType(arch, t)
// names is the list of names with this type.
names := fld.Names
if len(names) == 0 {
// Anonymous args will be called arg, arg1, arg2, ...
// Similarly so for return values: ret, ret1, ret2, ...
name := "arg"
if isret {
name = "ret"
}
if argnum > 0 {
name += strconv.Itoa(argnum)
}
names = []*ast.Ident{ast.NewIdent(name)}
}
argnum += len(names)
// Create variable for each name.
for _, id := range names {
name := id.Name
for _, c := range cc {
outer := name + c.outer
v := asmVar{
name: name + c.suffix,
kind: c.kind,
typ: c.typ,
off: offset + c.offset,
size: c.size,
}
if vo := fn.vars[outer]; vo != nil {
vo.inner = append(vo.inner, &v)
}
fn.vars[v.name] = &v
for i := 0; i < v.size; i++ {
fn.varByOffset[v.off+i] = &v
}
}
offset += size
}
}
}
m := make(map[string]*asmFunc)
for _, arch = range arches {
fn = &asmFunc{
arch: arch,
vars: make(map[string]*asmVar),
varByOffset: make(map[int]*asmVar),
}
offset = 0
addParams(decl.Type.Params.List, false)
if decl.Type.Results != nil && len(decl.Type.Results.List) > 0 {
offset += -offset & (arch.maxAlign - 1)
addParams(decl.Type.Results.List, true)
}
fn.size = offset
m[arch.name] = fn
}
return m
}
// asmCheckVar checks a single variable reference.
func asmCheckVar(badf func(string, ...interface{}), fn *asmFunc, line, expr string, off int, v *asmVar) {
m := asmOpcode.FindStringSubmatch(line)
if m == nil {
if !strings.HasPrefix(strings.TrimSpace(line), "//") {
badf("cannot find assembly opcode")
}
return
}
// Determine operand sizes from instruction.
// Typically the suffix suffices, but there are exceptions.
var src, dst, kind asmKind
op := m[1]
switch fn.arch.name + "." + op {
case "386.FMOVLP":
src, dst = 8, 4
case "arm.MOVD":
src = 8
case "arm.MOVW":
src = 4
case "arm.MOVH", "arm.MOVHU":
src = 2
case "arm.MOVB", "arm.MOVBU":
src = 1
// LEA* opcodes don't really read the second arg.
// They just take the address of it.
case "386.LEAL":
dst = 4
case "amd64.LEAQ":
dst = 8
case "amd64p32.LEAL":
dst = 4
default:
switch fn.arch.name {
case "386", "amd64":
if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "D") || strings.HasSuffix(op, "DP")) {
// FMOVDP, FXCHD, etc
src = 8
break
}
if strings.HasPrefix(op, "P") && strings.HasSuffix(op, "RD") {
// PINSRD, PEXTRD, etc
src = 4
break
}
if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "F") || strings.HasSuffix(op, "FP")) {
// FMOVFP, FXCHF, etc
src = 4
break
}
if strings.HasSuffix(op, "SD") {
// MOVSD, SQRTSD, etc
src = 8
break
}
if strings.HasSuffix(op, "SS") {
// MOVSS, SQRTSS, etc
src = 4
break
}
if strings.HasPrefix(op, "SET") {
// SETEQ, etc
src = 1
break
}
switch op[len(op)-1] {
case 'B':
src = 1
case 'W':
src = 2
case 'L':
src = 4
case 'D', 'Q':
src = 8
}
case "ppc64", "ppc64le":
// Strip standard suffixes to reveal size letter.
m := ppc64Suff.FindStringSubmatch(op)
if m != nil {
switch m[1][0] {
case 'B':
src = 1
case 'H':
src = 2
case 'W':
src = 4
case 'D':
src = 8
}
}
case "mips", "mipsle", "mips64", "mips64le":
switch op {
case "MOVB", "MOVBU":
src = 1
case "MOVH", "MOVHU":
src = 2
case "MOVW", "MOVWU", "MOVF":
src = 4
case "MOVV", "MOVD":
src = 8
}
case "s390x":
switch op {
case "MOVB", "MOVBZ":
src = 1
case "MOVH", "MOVHZ":
src = 2
case "MOVW", "MOVWZ", "FMOVS":
src = 4
case "MOVD", "FMOVD":
src = 8
}
}
}
if dst == 0 {
dst = src
}
// Determine whether the match we're holding
// is the first or second argument.
if strings.Index(line, expr) > strings.Index(line, ",") {
kind = dst
} else {
kind = src
}
vk := v.kind
vs := v.size
vt := v.typ
switch vk {
case asmInterface, asmEmptyInterface, asmString, asmSlice:
// allow reference to first word (pointer)
vk = v.inner[0].kind
vs = v.inner[0].size
vt = v.inner[0].typ
}
if off != v.off {
var inner bytes.Buffer
for i, vi := range v.inner {
if len(v.inner) > 1 {
fmt.Fprintf(&inner, ",")
}
fmt.Fprintf(&inner, " ")
if i == len(v.inner)-1 {
fmt.Fprintf(&inner, "or ")
}
fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
}
badf("invalid offset %s; expected %s+%d(FP)%s", expr, v.name, v.off, inner.String())
return
}
if kind != 0 && kind != vk {
var inner bytes.Buffer
if len(v.inner) > 0 {
fmt.Fprintf(&inner, " containing")
for i, vi := range v.inner {
if i > 0 && len(v.inner) > 2 {
fmt.Fprintf(&inner, ",")
}
fmt.Fprintf(&inner, " ")
if i > 0 && i == len(v.inner)-1 {
fmt.Fprintf(&inner, "and ")
}
fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
}
}
badf("invalid %s of %s; %s is %d-byte value%s", op, expr, vt, vs, inner.String())
}
}
|