1
0
mirror of https://github.com/golang/go synced 2024-11-11 22:20:22 -07:00

cmd/compile: allow conversion from slice to array ptr

Panic if the slice is too short.

Updates #395

Change-Id: I90f4bff2da5d8f3148ba06d2482084f32b25c29a
Reviewed-on: https://go-review.googlesource.com/c/go/+/301650
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This commit is contained in:
Josh Bleecher Snyder 2021-03-14 14:24:47 -07:00
parent 1c268431f4
commit faa4fa1a6e
33 changed files with 380 additions and 141 deletions

View File

@ -669,7 +669,10 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) {
k = e.spill(k, n)
}
e.expr(k.note(n, "interface-converted"), n.X)
case ir.OSLICE2ARRPTR:
// the slice pointer flows directly to the result
n := n.(*ir.ConvExpr)
e.expr(k, n.X)
case ir.ORECV:
n := n.(*ir.UnaryExpr)
e.discard(n.X)

View File

@ -277,7 +277,7 @@ func (n *ConvExpr) SetOp(op Op) {
switch op {
default:
panic(n.no("SetOp " + op.String()))
case OCONV, OCONVIFACE, OCONVNOP, OBYTES2STR, OBYTES2STRTMP, ORUNES2STR, OSTR2BYTES, OSTR2BYTESTMP, OSTR2RUNES, ORUNESTR:
case OCONV, OCONVIFACE, OCONVNOP, OBYTES2STR, OBYTES2STRTMP, ORUNES2STR, OSTR2BYTES, OSTR2BYTESTMP, OSTR2RUNES, ORUNESTR, OSLICE2ARRPTR:
n.op = op
}
}

View File

@ -206,6 +206,7 @@ var OpPrec = []int{
OPRINT: 8,
ORUNESTR: 8,
OSIZEOF: 8,
OSLICE2ARRPTR: 8,
OSTR2BYTES: 8,
OSTR2RUNES: 8,
OSTRUCTLIT: 8,
@ -804,7 +805,8 @@ func exprFmt(n Node, s fmt.State, prec int) {
ORUNES2STR,
OSTR2BYTES,
OSTR2RUNES,
ORUNESTR:
ORUNESTR,
OSLICE2ARRPTR:
n := n.(*ConvExpr)
if n.Type() == nil || n.Type().Sym() == nil {
fmt.Fprintf(s, "(%v)", n.Type())

View File

@ -137,6 +137,7 @@ const (
OSTR2BYTES // Type(Left) (Type is []byte, Left is a string)
OSTR2BYTESTMP // Type(Left) (Type is []byte, Left is a string, ephemeral)
OSTR2RUNES // Type(Left) (Type is []rune, Left is a string)
OSLICE2ARRPTR // Type(Left) (Type is *[N]T, Left is a []T)
// Left = Right or (if Colas=true) Left := Right
// If Colas, then Ninit includes a DCL node for Left.
OAS

View File

@ -29,143 +29,144 @@ func _() {
_ = x[OSTR2BYTES-18]
_ = x[OSTR2BYTESTMP-19]
_ = x[OSTR2RUNES-20]
_ = x[OAS-21]
_ = x[OAS2-22]
_ = x[OAS2DOTTYPE-23]
_ = x[OAS2FUNC-24]
_ = x[OAS2MAPR-25]
_ = x[OAS2RECV-26]
_ = x[OASOP-27]
_ = x[OCALL-28]
_ = x[OCALLFUNC-29]
_ = x[OCALLMETH-30]
_ = x[OCALLINTER-31]
_ = x[OCALLPART-32]
_ = x[OCAP-33]
_ = x[OCLOSE-34]
_ = x[OCLOSURE-35]
_ = x[OCOMPLIT-36]
_ = x[OMAPLIT-37]
_ = x[OSTRUCTLIT-38]
_ = x[OARRAYLIT-39]
_ = x[OSLICELIT-40]
_ = x[OPTRLIT-41]
_ = x[OCONV-42]
_ = x[OCONVIFACE-43]
_ = x[OCONVNOP-44]
_ = x[OCOPY-45]
_ = x[ODCL-46]
_ = x[ODCLFUNC-47]
_ = x[ODCLCONST-48]
_ = x[ODCLTYPE-49]
_ = x[ODELETE-50]
_ = x[ODOT-51]
_ = x[ODOTPTR-52]
_ = x[ODOTMETH-53]
_ = x[ODOTINTER-54]
_ = x[OXDOT-55]
_ = x[ODOTTYPE-56]
_ = x[ODOTTYPE2-57]
_ = x[OEQ-58]
_ = x[ONE-59]
_ = x[OLT-60]
_ = x[OLE-61]
_ = x[OGE-62]
_ = x[OGT-63]
_ = x[ODEREF-64]
_ = x[OINDEX-65]
_ = x[OINDEXMAP-66]
_ = x[OKEY-67]
_ = x[OSTRUCTKEY-68]
_ = x[OLEN-69]
_ = x[OMAKE-70]
_ = x[OMAKECHAN-71]
_ = x[OMAKEMAP-72]
_ = x[OMAKESLICE-73]
_ = x[OMAKESLICECOPY-74]
_ = x[OMUL-75]
_ = x[ODIV-76]
_ = x[OMOD-77]
_ = x[OLSH-78]
_ = x[ORSH-79]
_ = x[OAND-80]
_ = x[OANDNOT-81]
_ = x[ONEW-82]
_ = x[ONOT-83]
_ = x[OBITNOT-84]
_ = x[OPLUS-85]
_ = x[ONEG-86]
_ = x[OOROR-87]
_ = x[OPANIC-88]
_ = x[OPRINT-89]
_ = x[OPRINTN-90]
_ = x[OPAREN-91]
_ = x[OSEND-92]
_ = x[OSLICE-93]
_ = x[OSLICEARR-94]
_ = x[OSLICESTR-95]
_ = x[OSLICE3-96]
_ = x[OSLICE3ARR-97]
_ = x[OSLICEHEADER-98]
_ = x[ORECOVER-99]
_ = x[ORECV-100]
_ = x[ORUNESTR-101]
_ = x[OSELRECV2-102]
_ = x[OIOTA-103]
_ = x[OREAL-104]
_ = x[OIMAG-105]
_ = x[OCOMPLEX-106]
_ = x[OALIGNOF-107]
_ = x[OOFFSETOF-108]
_ = x[OSIZEOF-109]
_ = x[OMETHEXPR-110]
_ = x[OSTMTEXPR-111]
_ = x[OBLOCK-112]
_ = x[OBREAK-113]
_ = x[OCASE-114]
_ = x[OCONTINUE-115]
_ = x[ODEFER-116]
_ = x[OFALL-117]
_ = x[OFOR-118]
_ = x[OFORUNTIL-119]
_ = x[OGOTO-120]
_ = x[OIF-121]
_ = x[OLABEL-122]
_ = x[OGO-123]
_ = x[ORANGE-124]
_ = x[ORETURN-125]
_ = x[OSELECT-126]
_ = x[OSWITCH-127]
_ = x[OTYPESW-128]
_ = x[OFUNCINST-129]
_ = x[OTCHAN-130]
_ = x[OTMAP-131]
_ = x[OTSTRUCT-132]
_ = x[OTINTER-133]
_ = x[OTFUNC-134]
_ = x[OTARRAY-135]
_ = x[OTSLICE-136]
_ = x[OINLCALL-137]
_ = x[OEFACE-138]
_ = x[OITAB-139]
_ = x[OIDATA-140]
_ = x[OSPTR-141]
_ = x[OCFUNC-142]
_ = x[OCHECKNIL-143]
_ = x[OVARDEF-144]
_ = x[OVARKILL-145]
_ = x[OVARLIVE-146]
_ = x[ORESULT-147]
_ = x[OINLMARK-148]
_ = x[OLINKSYMOFFSET-149]
_ = x[OTAILCALL-150]
_ = x[OGETG-151]
_ = x[OEND-152]
_ = x[OSLICE2ARRPTR-21]
_ = x[OAS-22]
_ = x[OAS2-23]
_ = x[OAS2DOTTYPE-24]
_ = x[OAS2FUNC-25]
_ = x[OAS2MAPR-26]
_ = x[OAS2RECV-27]
_ = x[OASOP-28]
_ = x[OCALL-29]
_ = x[OCALLFUNC-30]
_ = x[OCALLMETH-31]
_ = x[OCALLINTER-32]
_ = x[OCALLPART-33]
_ = x[OCAP-34]
_ = x[OCLOSE-35]
_ = x[OCLOSURE-36]
_ = x[OCOMPLIT-37]
_ = x[OMAPLIT-38]
_ = x[OSTRUCTLIT-39]
_ = x[OARRAYLIT-40]
_ = x[OSLICELIT-41]
_ = x[OPTRLIT-42]
_ = x[OCONV-43]
_ = x[OCONVIFACE-44]
_ = x[OCONVNOP-45]
_ = x[OCOPY-46]
_ = x[ODCL-47]
_ = x[ODCLFUNC-48]
_ = x[ODCLCONST-49]
_ = x[ODCLTYPE-50]
_ = x[ODELETE-51]
_ = x[ODOT-52]
_ = x[ODOTPTR-53]
_ = x[ODOTMETH-54]
_ = x[ODOTINTER-55]
_ = x[OXDOT-56]
_ = x[ODOTTYPE-57]
_ = x[ODOTTYPE2-58]
_ = x[OEQ-59]
_ = x[ONE-60]
_ = x[OLT-61]
_ = x[OLE-62]
_ = x[OGE-63]
_ = x[OGT-64]
_ = x[ODEREF-65]
_ = x[OINDEX-66]
_ = x[OINDEXMAP-67]
_ = x[OKEY-68]
_ = x[OSTRUCTKEY-69]
_ = x[OLEN-70]
_ = x[OMAKE-71]
_ = x[OMAKECHAN-72]
_ = x[OMAKEMAP-73]
_ = x[OMAKESLICE-74]
_ = x[OMAKESLICECOPY-75]
_ = x[OMUL-76]
_ = x[ODIV-77]
_ = x[OMOD-78]
_ = x[OLSH-79]
_ = x[ORSH-80]
_ = x[OAND-81]
_ = x[OANDNOT-82]
_ = x[ONEW-83]
_ = x[ONOT-84]
_ = x[OBITNOT-85]
_ = x[OPLUS-86]
_ = x[ONEG-87]
_ = x[OOROR-88]
_ = x[OPANIC-89]
_ = x[OPRINT-90]
_ = x[OPRINTN-91]
_ = x[OPAREN-92]
_ = x[OSEND-93]
_ = x[OSLICE-94]
_ = x[OSLICEARR-95]
_ = x[OSLICESTR-96]
_ = x[OSLICE3-97]
_ = x[OSLICE3ARR-98]
_ = x[OSLICEHEADER-99]
_ = x[ORECOVER-100]
_ = x[ORECV-101]
_ = x[ORUNESTR-102]
_ = x[OSELRECV2-103]
_ = x[OIOTA-104]
_ = x[OREAL-105]
_ = x[OIMAG-106]
_ = x[OCOMPLEX-107]
_ = x[OALIGNOF-108]
_ = x[OOFFSETOF-109]
_ = x[OSIZEOF-110]
_ = x[OMETHEXPR-111]
_ = x[OSTMTEXPR-112]
_ = x[OBLOCK-113]
_ = x[OBREAK-114]
_ = x[OCASE-115]
_ = x[OCONTINUE-116]
_ = x[ODEFER-117]
_ = x[OFALL-118]
_ = x[OFOR-119]
_ = x[OFORUNTIL-120]
_ = x[OGOTO-121]
_ = x[OIF-122]
_ = x[OLABEL-123]
_ = x[OGO-124]
_ = x[ORANGE-125]
_ = x[ORETURN-126]
_ = x[OSELECT-127]
_ = x[OSWITCH-128]
_ = x[OTYPESW-129]
_ = x[OFUNCINST-130]
_ = x[OTCHAN-131]
_ = x[OTMAP-132]
_ = x[OTSTRUCT-133]
_ = x[OTINTER-134]
_ = x[OTFUNC-135]
_ = x[OTARRAY-136]
_ = x[OTSLICE-137]
_ = x[OINLCALL-138]
_ = x[OEFACE-139]
_ = x[OITAB-140]
_ = x[OIDATA-141]
_ = x[OSPTR-142]
_ = x[OCFUNC-143]
_ = x[OCHECKNIL-144]
_ = x[OVARDEF-145]
_ = x[OVARKILL-146]
_ = x[OVARLIVE-147]
_ = x[ORESULT-148]
_ = x[OINLMARK-149]
_ = x[OLINKSYMOFFSET-150]
_ = x[OTAILCALL-151]
_ = x[OGETG-152]
_ = x[OEND-153]
}
const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFMETHEXPRSTMTEXPRBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETTAILCALLGETGEND"
const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFMETHEXPRSTMTEXPRBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETTAILCALLGETGEND"
var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 126, 129, 139, 146, 153, 160, 164, 168, 176, 184, 193, 201, 204, 209, 216, 223, 229, 238, 246, 254, 260, 264, 273, 280, 284, 287, 294, 302, 309, 315, 318, 324, 331, 339, 343, 350, 358, 360, 362, 364, 366, 368, 370, 375, 380, 388, 391, 400, 403, 407, 415, 422, 431, 444, 447, 450, 453, 456, 459, 462, 468, 471, 474, 480, 484, 487, 491, 496, 501, 507, 512, 516, 521, 529, 537, 543, 552, 563, 570, 574, 581, 589, 593, 597, 601, 608, 615, 623, 629, 637, 645, 650, 655, 659, 667, 672, 676, 679, 687, 691, 693, 698, 700, 705, 711, 717, 723, 729, 737, 742, 746, 753, 759, 764, 770, 776, 783, 788, 792, 797, 801, 806, 814, 820, 827, 834, 840, 847, 860, 868, 872, 875}
var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 136, 138, 141, 151, 158, 165, 172, 176, 180, 188, 196, 205, 213, 216, 221, 228, 235, 241, 250, 258, 266, 272, 276, 285, 292, 296, 299, 306, 314, 321, 327, 330, 336, 343, 351, 355, 362, 370, 372, 374, 376, 378, 380, 382, 387, 392, 400, 403, 412, 415, 419, 427, 434, 443, 456, 459, 462, 465, 468, 471, 474, 480, 483, 486, 492, 496, 499, 503, 508, 513, 519, 524, 528, 533, 541, 549, 555, 564, 575, 582, 586, 593, 601, 605, 609, 613, 620, 627, 635, 641, 649, 657, 662, 667, 671, 679, 684, 688, 691, 699, 703, 705, 710, 712, 717, 723, 729, 735, 741, 749, 754, 758, 765, 771, 776, 782, 788, 795, 800, 804, 809, 813, 818, 826, 832, 839, 846, 852, 859, 872, 880, 884, 887}
func (i Op) String() string {
if i >= Op(len(_Op_index)-1) {

View File

@ -508,7 +508,7 @@ func (x *expandState) rewriteSelect(leaf *Value, selector *Value, offset int64,
ls := x.rewriteSelect(leaf, selector.Args[0], offset, regOffset)
locs = x.splitSlots(ls, ".ptr", 0, x.typs.BytePtr)
case OpSlicePtr:
case OpSlicePtr, OpSlicePtrUnchecked:
w := selector.Args[0]
ls := x.rewriteSelect(leaf, w, offset, regOffset)
locs = x.splitSlots(ls, ".ptr", 0, types.NewPtr(w.Type.Elem()))
@ -1202,7 +1202,7 @@ func expandCalls(f *Func) {
case OpStructSelect, OpArraySelect,
OpIData, OpITab,
OpStringPtr, OpStringLen,
OpSlicePtr, OpSliceLen, OpSliceCap,
OpSlicePtr, OpSliceLen, OpSliceCap, OpSlicePtrUnchecked,
OpComplexReal, OpComplexImag,
OpInt64Hi, OpInt64Lo:
w := v.Args[0]

View File

@ -56,6 +56,7 @@
(SlicePtr (SliceMake ptr _ _ )) => ptr
(SliceLen (SliceMake _ len _)) => len
(SliceCap (SliceMake _ _ cap)) => cap
(SlicePtrUnchecked (SliceMake ptr _ _ )) => ptr
(Load <t> ptr mem) && t.IsSlice() =>
(SliceMake

View File

@ -479,6 +479,10 @@ var genericOps = []opData{
{name: "SlicePtr", argLength: 1, typ: "BytePtr"}, // ptr(arg0)
{name: "SliceLen", argLength: 1}, // len(arg0)
{name: "SliceCap", argLength: 1}, // cap(arg0)
// SlicePtrUnchecked, like SlicePtr, extracts the pointer from a slice.
// SlicePtr values are assumed non-nil, because they are guarded by bounds checks.
// SlicePtrUnchecked values can be nil.
{name: "SlicePtrUnchecked", argLength: 1},
// Complex (part/whole)
{name: "ComplexMake", argLength: 2}, // arg0=real, arg1=imag

View File

@ -469,6 +469,7 @@ const (
BoundsSlice3BU // ... with unsigned high
BoundsSlice3C // 3-arg slicing operation, 0 <= low <= high failed
BoundsSlice3CU // ... with unsigned low
BoundsConvert // conversion to array pointer failed
BoundsKindCount
)
@ -496,7 +497,8 @@ func boundsABI(b int64) int {
case BoundsSlice3Alen,
BoundsSlice3AlenU,
BoundsSlice3Acap,
BoundsSlice3AcapU:
BoundsSlice3AcapU,
BoundsConvert:
return 0
case BoundsSliceAlen,
BoundsSliceAlenU,

View File

@ -2834,6 +2834,7 @@ const (
OpSlicePtr
OpSliceLen
OpSliceCap
OpSlicePtrUnchecked
OpComplexMake
OpComplexReal
OpComplexImag
@ -35898,6 +35899,11 @@ var opcodeTable = [...]opInfo{
argLen: 1,
generic: true,
},
{
name: "SlicePtrUnchecked",
argLen: 1,
generic: true,
},
{
name: "ComplexMake",
argLen: 2,

View File

@ -23,6 +23,8 @@ func rewriteValuedec(v *Value) bool {
return rewriteValuedec_OpSliceLen(v)
case OpSlicePtr:
return rewriteValuedec_OpSlicePtr(v)
case OpSlicePtrUnchecked:
return rewriteValuedec_OpSlicePtrUnchecked(v)
case OpStore:
return rewriteValuedec_OpStore(v)
case OpStringLen:
@ -248,6 +250,20 @@ func rewriteValuedec_OpSlicePtr(v *Value) bool {
}
return false
}
func rewriteValuedec_OpSlicePtrUnchecked(v *Value) bool {
v_0 := v.Args[0]
// match: (SlicePtrUnchecked (SliceMake ptr _ _ ))
// result: ptr
for {
if v_0.Op != OpSliceMake {
break
}
ptr := v_0.Args[0]
v.copyOf(ptr)
return true
}
return false
}
func rewriteValuedec_OpStore(v *Value) bool {
v_2 := v.Args[2]
v_1 := v.Args[1]

View File

@ -164,6 +164,7 @@ func InitConfig() {
BoundsCheckFunc[ssa.BoundsSlice3BU] = typecheck.LookupRuntimeFunc("goPanicSlice3BU")
BoundsCheckFunc[ssa.BoundsSlice3C] = typecheck.LookupRuntimeFunc("goPanicSlice3C")
BoundsCheckFunc[ssa.BoundsSlice3CU] = typecheck.LookupRuntimeFunc("goPanicSlice3CU")
BoundsCheckFunc[ssa.BoundsConvert] = typecheck.LookupRuntimeFunc("goPanicSliceConvert")
} else {
BoundsCheckFunc[ssa.BoundsIndex] = typecheck.LookupRuntimeFunc("panicIndex")
BoundsCheckFunc[ssa.BoundsIndexU] = typecheck.LookupRuntimeFunc("panicIndexU")
@ -181,6 +182,7 @@ func InitConfig() {
BoundsCheckFunc[ssa.BoundsSlice3BU] = typecheck.LookupRuntimeFunc("panicSlice3BU")
BoundsCheckFunc[ssa.BoundsSlice3C] = typecheck.LookupRuntimeFunc("panicSlice3C")
BoundsCheckFunc[ssa.BoundsSlice3CU] = typecheck.LookupRuntimeFunc("panicSlice3CU")
BoundsCheckFunc[ssa.BoundsConvert] = typecheck.LookupRuntimeFunc("panicSliceConvert")
}
if Arch.LinkArch.PtrSize == 4 {
ExtendCheckFunc[ssa.BoundsIndex] = typecheck.LookupRuntimeVar("panicExtendIndex")
@ -3148,6 +3150,18 @@ func (s *state) expr(n ir.Node) *ssa.Value {
p, l, _ := s.slice(v, i, j, nil, n.Bounded())
return s.newValue2(ssa.OpStringMake, n.Type(), p, l)
case ir.OSLICE2ARRPTR:
// if arrlen > slice.len {
// panic(...)
// }
// slice.ptr
n := n.(*ir.ConvExpr)
v := s.expr(n.X)
arrlen := s.constInt(types.Types[types.TINT], n.Type().Elem().NumElem())
cap := s.newValue1(ssa.OpSliceLen, types.Types[types.TINT], v)
s.boundsCheck(arrlen, cap, ssa.BoundsConvert, false)
return s.newValue1(ssa.OpSlicePtrUnchecked, types.Types[types.TINT], v)
case ir.OCALLFUNC:
n := n.(*ir.CallExpr)
if ir.IsIntrinsicCall(n) {

View File

@ -39,6 +39,7 @@ var runtimeDecls = [...]struct {
{"goPanicSlice3BU", funcTag, 18},
{"goPanicSlice3C", funcTag, 16},
{"goPanicSlice3CU", funcTag, 18},
{"goPanicSliceConvert", funcTag, 16},
{"printbool", funcTag, 19},
{"printfloat", funcTag, 21},
{"printint", funcTag, 23},

View File

@ -46,6 +46,7 @@ func goPanicSlice3B(x int, y int)
func goPanicSlice3BU(x uint, y int)
func goPanicSlice3C(x int, y int)
func goPanicSlice3CU(x uint, y int)
func goPanicSliceConvert(x int, y int)
func printbool(bool)
func printfloat(float64)

View File

@ -574,7 +574,7 @@ func Convertop(srcConstant bool, src, dst *types.Type) (ir.Op, string) {
return ir.OCONVNOP, ""
}
// src is map and dst is a pointer to corresponding hmap.
// 10. src is map and dst is a pointer to corresponding hmap.
// This rule is needed for the implementation detail that
// go gc maps are implemented as a pointer to a hmap struct.
if src.Kind() == types.TMAP && dst.IsPtr() &&
@ -582,6 +582,16 @@ func Convertop(srcConstant bool, src, dst *types.Type) (ir.Op, string) {
return ir.OCONVNOP, ""
}
// 11. src is a slice and dst is a pointer-to-array.
// They must have same element type.
if src.IsSlice() && dst.IsPtr() && dst.Elem().IsArray() &&
types.Identical(src.Elem(), dst.Elem().Elem()) {
if !types.AllowsGoVersion(curpkg(), 1, 17) {
return ir.OXXX, ":\n\tconversion of slices to array pointers only supported as of -lang=go1.17"
}
return ir.OSLICE2ARRPTR, ""
}
return ir.OXXX, ""
}

View File

@ -1578,6 +1578,9 @@ func TestConvertibleTo(t *testing.T) {
{newDefined(new(Struct)), new(Struct), true},
{newDefined(Typ[Int]), new(Struct), false},
{Typ[UntypedInt], Typ[Int], true},
{NewSlice(Typ[Int]), NewPointer(NewArray(Typ[Int], 10)), true},
{NewSlice(Typ[Int]), NewArray(Typ[Int], 10), false},
{NewSlice(Typ[Int]), NewPointer(NewArray(Typ[Uint], 10)), false},
// Untyped string values are not permitted by the spec, so the below
// behavior is undefined.
{Typ[UntypedString], Typ[String], true},

View File

@ -135,6 +135,18 @@ func (x *operand) convertibleTo(check *Checker, T Type) bool {
return true
}
// "x is a slice, T is a pointer-to-array type,
// and the slice and array types have identical element types."
if s := asSlice(V); s != nil {
if p := asPointer(T); p != nil {
if a := asArray(p.Elem()); a != nil {
if check.identical(s.Elem(), a.Elem()) {
return true
}
}
}
}
return false
}

View File

@ -205,6 +205,11 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
n := n.(*ir.ConvExpr)
return walkConv(n, init)
case ir.OSLICE2ARRPTR:
n := n.(*ir.ConvExpr)
n.X = walkExpr(n.X, init)
return n
case ir.ODIV, ir.OMOD:
n := n.(*ir.BinaryExpr)
return walkDivMod(n, init)

View File

@ -163,6 +163,10 @@ func TestStdTest(t *testing.T) {
"embedfunc.go", // tests //go:embed
"embedvers.go", // tests //go:embed
"linkname2.go", // go/types doesn't check validity of //go:xxx directives
"convert2.go", // temporary: go/types doesn't know yet about converting from slices to array pointers
"convert4.go", // temporary: go/types doesn't know yet about converting from slices to array pointers
"escape_slice.go", // temporary: go/types doesn't know yet about converting from slices to array pointers
)
}

View File

@ -1473,6 +1473,10 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-8
MOVL AX, x+0(FP)
MOVL CX, y+4(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-8
MOVL DX, x+0(FP)
MOVL BX, y+4(FP)
JMP runtime·goPanicSliceConvert(SB)
// Extended versions for 64-bit indexes.
TEXT runtime·panicExtendIndex(SB),NOSPLIT,$0-12

View File

@ -2091,6 +2091,14 @@ TEXT runtime·panicSlice3CU<ABIInternal>(SB),NOSPLIT,$0-16
MOVQ CX, y+8(FP)
#endif
JMP runtime·goPanicSlice3CU<ABIInternal>(SB)
TEXT runtime·panicSliceConvert<ABIInternal>(SB),NOSPLIT,$0-16
#ifdef GOEXPERIMENT_regabiargs
MOVQ DX, AX
#else
MOVQ DX, x+0(FP)
MOVQ BX, y+8(FP)
#endif
JMP runtime·goPanicSliceConvert<ABIInternal>(SB)
#ifdef GOOS_android
// Use the free TLS_SLOT_APP slot #2 on Android Q.

View File

@ -992,6 +992,10 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-8
MOVW R0, x+0(FP)
MOVW R1, y+4(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-8
MOVW R2, x+0(FP)
MOVW R3, y+4(FP)
JMP runtime·goPanicSliceConvert(SB)
// Extended versions for 64-bit indexes.
TEXT runtime·panicExtendIndex(SB),NOSPLIT,$0-12

View File

@ -1314,3 +1314,7 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
MOVD R0, x+0(FP)
MOVD R1, y+8(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
MOVD R2, x+0(FP)
MOVD R3, y+8(FP)
JMP runtime·goPanicSliceConvert(SB)

View File

@ -805,3 +805,7 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
MOVV R1, x+0(FP)
MOVV R2, y+8(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
MOVV R3, x+0(FP)
MOVV R4, y+8(FP)
JMP runtime·goPanicSliceConvert(SB)

View File

@ -801,6 +801,10 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-8
MOVW R1, x+0(FP)
MOVW R2, y+4(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-8
MOVW R3, x+0(FP)
MOVW R4, y+4(FP)
JMP runtime·goPanicSliceConvert(SB)
// Extended versions for 64-bit indexes.
TEXT runtime·panicExtendIndex(SB),NOSPLIT,$0-12

View File

@ -1022,3 +1022,7 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
MOVD R3, x+0(FP)
MOVD R4, y+8(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
MOVD R5, x+0(FP)
MOVD R6, y+8(FP)
JMP runtime·goPanicSliceConvert(SB)

View File

@ -806,6 +806,10 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
MOV T0, x+0(FP)
MOV T1, y+8(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
MOV T2, x+0(FP)
MOV T3, y+8(FP)
JMP runtime·goPanicSliceConvert(SB)
DATA runtime·mainPC+0(SB)/8,$runtime·main(SB)
GLOBL runtime·mainPC(SB),RODATA,$8

View File

@ -906,3 +906,7 @@ TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
MOVD R0, x+0(FP)
MOVD R1, y+8(FP)
JMP runtime·goPanicSlice3CU(SB)
TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
MOVD R2, x+0(FP)
MOVD R3, y+8(FP)
JMP runtime·goPanicSliceConvert(SB)

View File

@ -134,6 +134,7 @@ const (
boundsSlice3B // s[?:x:y], 0 <= x <= y failed (but boundsSlice3A didn't happen)
boundsSlice3C // s[x:y:?], 0 <= x <= y failed (but boundsSlice3A/B didn't happen)
boundsConvert // (*[x]T)(s), 0 <= x <= len(s) failed
// Note: in the above, len(s) and cap(s) are stored in y
)
@ -149,6 +150,7 @@ var boundsErrorFmts = [...]string{
boundsSlice3Acap: "slice bounds out of range [::%x] with capacity %y",
boundsSlice3B: "slice bounds out of range [:%x:%y]",
boundsSlice3C: "slice bounds out of range [%x:%y:]",
boundsConvert: "cannot convert slice with length %y to pointer to array with length %x",
}
// boundsNegErrorFmts are overriding formats if x is negative. In this case there's no need to report y.

View File

@ -160,6 +160,12 @@ func goPanicSlice3CU(x uint, y int) {
panic(boundsError{x: int64(x), signed: false, y: y, code: boundsSlice3C})
}
// failures in the conversion (*[x]T)s, 0 <= x <= y, x == cap(s)
func goPanicSliceConvert(x int, y int) {
panicCheck1(getcallerpc(), "slice length too short to convert to pointer to array")
panic(boundsError{x: int64(x), signed: true, y: y, code: boundsConvert})
}
// Implemented in assembly, as they take arguments in registers.
// Declared here to mark them as ABIInternal.
func panicIndex(x int, y int)
@ -178,6 +184,7 @@ func panicSlice3B(x int, y int)
func panicSlice3BU(x uint, y int)
func panicSlice3C(x int, y int)
func panicSlice3CU(x uint, y int)
func panicSliceConvert(x int, y int)
var shiftError = error(errorString("negative shift amount"))

View File

@ -313,3 +313,17 @@ func _() {
t = u // ERROR "cannot use .* in assignment|incompatible type"
t = (*T)(u) // ERROR "cannot convert"
}
func _() {
var s []byte
_ = ([4]byte)(s) // ERROR "cannot convert"
_ = (*[4]byte)(s)
type A [4]byte
_ = (A)(s) // ERROR "cannot convert"
_ = (*A)(s)
type P *[4]byte
_ = (P)(s)
_ = (*P)(s) // ERROR "cannot convert"
}

86
test/convert4.go Normal file
View File

@ -0,0 +1,86 @@
// run
// Copyright 2020 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.
// Test conversion from slice to array pointer.
package main
func wantPanic(fn func(), s string) {
defer func() {
err := recover()
if err == nil {
panic("expected panic")
}
if got := err.(error).Error(); got != s {
panic("expected panic " + s + " got " + got)
}
}()
fn()
}
func main() {
s := make([]byte, 8, 10)
if p := (*[8]byte)(s); &p[0] != &s[0] {
panic("*[8]byte conversion failed")
}
wantPanic(
func() {
_ = (*[9]byte)(s)
},
"runtime error: cannot convert slice with length 8 to pointer to array with length 9",
)
var n []byte
if p := (*[0]byte)(n); p != nil {
panic("nil slice converted to *[0]byte should be nil")
}
z := make([]byte, 0)
if p := (*[0]byte)(z); p == nil {
panic("empty slice converted to *[0]byte should be non-nil")
}
// Test with named types
type Slice []int
type Int4 [4]int
type PInt4 *[4]int
ii := make(Slice, 4)
if p := (*Int4)(ii); &p[0] != &ii[0] {
panic("*Int4 conversion failed")
}
if p := PInt4(ii); &p[0] != &ii[0] {
panic("PInt4 conversion failed")
}
}
// test static variable conversion
var (
ss = make([]string, 10)
s5 = (*[5]string)(ss)
s10 = (*[10]string)(ss)
ns []string
ns0 = (*[0]string)(ns)
zs = make([]string, 0)
zs0 = (*[0]string)(zs)
)
func init() {
if &ss[0] != &s5[0] {
panic("s5 conversion failed")
}
if &ss[0] != &s10[0] {
panic("s5 conversion failed")
}
if ns0 != nil {
panic("ns0 should be nil")
}
if zs0 == nil {
panic("zs0 should not be nil")
}
}

View File

@ -101,6 +101,10 @@ func slice11() {
_ = s
}
func slice12(x []int) *[1]int { // ERROR "leaking param: x to result ~r1 level=0$"
return (*[1]int)(x)
}
func envForDir(dir string) []string { // ERROR "dir does not escape"
env := os.Environ()
return mergeEnvLists([]string{"PWD=" + dir}, env) // ERROR ".PWD=. \+ dir escapes to heap" "\[\]string{...} does not escape"