cmd/compile: add clear(x) builtin
To clear map, and zero content of slice.
Updates #56351
Change-Id: I5f81dfbc465500f5acadaf2c6beb9b5f0d2c4045
Reviewed-on: https://go-review.googlesource.com/c/go/+/453395
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
diff --git a/src/cmd/compile/internal/escape/call.go b/src/cmd/compile/internal/escape/call.go
index f1c2c30..f9eced7 100644
--- a/src/cmd/compile/internal/escape/call.go
+++ b/src/cmd/compile/internal/escape/call.go
@@ -179,7 +179,7 @@
argument(e.discardHole(), &call.Args[i])
}
- case ir.OLEN, ir.OCAP, ir.OREAL, ir.OIMAG, ir.OCLOSE:
+ case ir.OLEN, ir.OCAP, ir.OREAL, ir.OIMAG, ir.OCLOSE, ir.OCLEAR:
call := call.(*ir.UnaryExpr)
argument(e.discardHole(), &call.X)
diff --git a/src/cmd/compile/internal/escape/stmt.go b/src/cmd/compile/internal/escape/stmt.go
index 90d4f2d..1ce04d9 100644
--- a/src/cmd/compile/internal/escape/stmt.go
+++ b/src/cmd/compile/internal/escape/stmt.go
@@ -180,7 +180,7 @@
dsts[i] = res.Nname.(*ir.Name)
}
e.assignList(dsts, n.Results, "return", n)
- case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OINLCALL, ir.OCLOSE, ir.OCOPY, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
+ case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OINLCALL, ir.OCLEAR, ir.OCLOSE, ir.OCOPY, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
e.call(nil, n)
case ir.OGO, ir.ODEFER:
n := n.(*ir.GoDeferStmt)
diff --git a/src/cmd/compile/internal/ir/expr.go b/src/cmd/compile/internal/ir/expr.go
index a481b14..95c142b 100644
--- a/src/cmd/compile/internal/ir/expr.go
+++ b/src/cmd/compile/internal/ir/expr.go
@@ -747,7 +747,7 @@
default:
panic(n.no("SetOp " + op.String()))
case OBITNOT, ONEG, ONOT, OPLUS, ORECV,
- OALIGNOF, OCAP, OCLOSE, OIMAG, OLEN, ONEW,
+ OALIGNOF, OCAP, OCLEAR, OCLOSE, OIMAG, OLEN, ONEW,
OOFFSETOF, OPANIC, OREAL, OSIZEOF,
OCHECKNIL, OCFUNC, OIDATA, OITAB, OSPTR,
OUNSAFESTRINGDATA, OUNSAFESLICEDATA:
diff --git a/src/cmd/compile/internal/ir/fmt.go b/src/cmd/compile/internal/ir/fmt.go
index bac172d..ccd295d 100644
--- a/src/cmd/compile/internal/ir/fmt.go
+++ b/src/cmd/compile/internal/ir/fmt.go
@@ -39,6 +39,7 @@
OCALL: "function call", // not actual syntax
OCAP: "cap",
OCASE: "case",
+ OCLEAR: "clear",
OCLOSE: "close",
OCOMPLEX: "complex",
OBITNOT: "^",
@@ -182,6 +183,7 @@
OCALLMETH: 8,
OCALL: 8,
OCAP: 8,
+ OCLEAR: 8,
OCLOSE: 8,
OCOMPLIT: 8,
OCONVIFACE: 8,
@@ -767,6 +769,7 @@
case OREAL,
OIMAG,
OCAP,
+ OCLEAR,
OCLOSE,
OLEN,
ONEW,
diff --git a/src/cmd/compile/internal/ir/node.go b/src/cmd/compile/internal/ir/node.go
index b42f914..ad25b9f 100644
--- a/src/cmd/compile/internal/ir/node.go
+++ b/src/cmd/compile/internal/ir/node.go
@@ -159,6 +159,7 @@
OCALLMETH // X(Args) (direct method call x.Method(args))
OCALLINTER // X(Args) (interface method call x.Method(args))
OCAP // cap(X)
+ OCLEAR // clear(X)
OCLOSE // close(X)
OCLOSURE // func Type { Func.Closure.Body } (func literal)
OCOMPLIT // Type{List} (composite literal, not yet lowered to specific form)
diff --git a/src/cmd/compile/internal/ir/op_string.go b/src/cmd/compile/internal/ir/op_string.go
index d84a08e..e086145 100644
--- a/src/cmd/compile/internal/ir/op_string.go
+++ b/src/cmd/compile/internal/ir/op_string.go
@@ -42,132 +42,133 @@
_ = x[OCALLMETH-31]
_ = x[OCALLINTER-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[OCONVIDATA-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[OSTRINGHEADER-100]
- _ = x[ORECOVER-101]
- _ = x[ORECOVERFP-102]
- _ = x[ORECV-103]
- _ = x[ORUNESTR-104]
- _ = x[OSELRECV2-105]
- _ = x[OREAL-106]
- _ = x[OIMAG-107]
- _ = x[OCOMPLEX-108]
- _ = x[OALIGNOF-109]
- _ = x[OOFFSETOF-110]
- _ = x[OSIZEOF-111]
- _ = x[OUNSAFEADD-112]
- _ = x[OUNSAFESLICE-113]
- _ = x[OUNSAFESLICEDATA-114]
- _ = x[OUNSAFESTRING-115]
- _ = x[OUNSAFESTRINGDATA-116]
- _ = x[OMETHEXPR-117]
- _ = x[OMETHVALUE-118]
- _ = x[OBLOCK-119]
- _ = x[OBREAK-120]
- _ = x[OCASE-121]
- _ = x[OCONTINUE-122]
- _ = x[ODEFER-123]
- _ = x[OFALL-124]
- _ = x[OFOR-125]
- _ = x[OGOTO-126]
- _ = x[OIF-127]
- _ = x[OLABEL-128]
- _ = x[OGO-129]
- _ = x[ORANGE-130]
- _ = x[ORETURN-131]
- _ = x[OSELECT-132]
- _ = x[OSWITCH-133]
- _ = x[OTYPESW-134]
- _ = x[OFUNCINST-135]
- _ = x[OINLCALL-136]
- _ = x[OEFACE-137]
- _ = x[OITAB-138]
- _ = x[OIDATA-139]
- _ = x[OSPTR-140]
- _ = x[OCFUNC-141]
- _ = x[OCHECKNIL-142]
- _ = x[ORESULT-143]
- _ = x[OINLMARK-144]
- _ = x[OLINKSYMOFFSET-145]
- _ = x[OJUMPTABLE-146]
- _ = x[ODYNAMICDOTTYPE-147]
- _ = x[ODYNAMICDOTTYPE2-148]
- _ = x[ODYNAMICTYPE-149]
- _ = x[OTAILCALL-150]
- _ = x[OGETG-151]
- _ = x[OGETCALLERPC-152]
- _ = x[OGETCALLERSP-153]
- _ = x[OEND-154]
+ _ = x[OCLEAR-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[OCONVIDATA-45]
+ _ = x[OCONVNOP-46]
+ _ = x[OCOPY-47]
+ _ = x[ODCL-48]
+ _ = x[ODCLFUNC-49]
+ _ = x[ODCLCONST-50]
+ _ = x[ODCLTYPE-51]
+ _ = x[ODELETE-52]
+ _ = x[ODOT-53]
+ _ = x[ODOTPTR-54]
+ _ = x[ODOTMETH-55]
+ _ = x[ODOTINTER-56]
+ _ = x[OXDOT-57]
+ _ = x[ODOTTYPE-58]
+ _ = x[ODOTTYPE2-59]
+ _ = x[OEQ-60]
+ _ = x[ONE-61]
+ _ = x[OLT-62]
+ _ = x[OLE-63]
+ _ = x[OGE-64]
+ _ = x[OGT-65]
+ _ = x[ODEREF-66]
+ _ = x[OINDEX-67]
+ _ = x[OINDEXMAP-68]
+ _ = x[OKEY-69]
+ _ = x[OSTRUCTKEY-70]
+ _ = x[OLEN-71]
+ _ = x[OMAKE-72]
+ _ = x[OMAKECHAN-73]
+ _ = x[OMAKEMAP-74]
+ _ = x[OMAKESLICE-75]
+ _ = x[OMAKESLICECOPY-76]
+ _ = x[OMUL-77]
+ _ = x[ODIV-78]
+ _ = x[OMOD-79]
+ _ = x[OLSH-80]
+ _ = x[ORSH-81]
+ _ = x[OAND-82]
+ _ = x[OANDNOT-83]
+ _ = x[ONEW-84]
+ _ = x[ONOT-85]
+ _ = x[OBITNOT-86]
+ _ = x[OPLUS-87]
+ _ = x[ONEG-88]
+ _ = x[OOROR-89]
+ _ = x[OPANIC-90]
+ _ = x[OPRINT-91]
+ _ = x[OPRINTN-92]
+ _ = x[OPAREN-93]
+ _ = x[OSEND-94]
+ _ = x[OSLICE-95]
+ _ = x[OSLICEARR-96]
+ _ = x[OSLICESTR-97]
+ _ = x[OSLICE3-98]
+ _ = x[OSLICE3ARR-99]
+ _ = x[OSLICEHEADER-100]
+ _ = x[OSTRINGHEADER-101]
+ _ = x[ORECOVER-102]
+ _ = x[ORECOVERFP-103]
+ _ = x[ORECV-104]
+ _ = x[ORUNESTR-105]
+ _ = x[OSELRECV2-106]
+ _ = x[OREAL-107]
+ _ = x[OIMAG-108]
+ _ = x[OCOMPLEX-109]
+ _ = x[OALIGNOF-110]
+ _ = x[OOFFSETOF-111]
+ _ = x[OSIZEOF-112]
+ _ = x[OUNSAFEADD-113]
+ _ = x[OUNSAFESLICE-114]
+ _ = x[OUNSAFESLICEDATA-115]
+ _ = x[OUNSAFESTRING-116]
+ _ = x[OUNSAFESTRINGDATA-117]
+ _ = x[OMETHEXPR-118]
+ _ = x[OMETHVALUE-119]
+ _ = x[OBLOCK-120]
+ _ = x[OBREAK-121]
+ _ = x[OCASE-122]
+ _ = x[OCONTINUE-123]
+ _ = x[ODEFER-124]
+ _ = x[OFALL-125]
+ _ = x[OFOR-126]
+ _ = x[OGOTO-127]
+ _ = x[OIF-128]
+ _ = x[OLABEL-129]
+ _ = x[OGO-130]
+ _ = x[ORANGE-131]
+ _ = x[ORETURN-132]
+ _ = x[OSELECT-133]
+ _ = x[OSWITCH-134]
+ _ = x[OTYPESW-135]
+ _ = x[OFUNCINST-136]
+ _ = x[OINLCALL-137]
+ _ = x[OEFACE-138]
+ _ = x[OITAB-139]
+ _ = x[OIDATA-140]
+ _ = x[OSPTR-141]
+ _ = x[OCFUNC-142]
+ _ = x[OCHECKNIL-143]
+ _ = x[ORESULT-144]
+ _ = x[OINLMARK-145]
+ _ = x[OLINKSYMOFFSET-146]
+ _ = x[OJUMPTABLE-147]
+ _ = x[ODYNAMICDOTTYPE-148]
+ _ = x[ODYNAMICDOTTYPE2-149]
+ _ = x[ODYNAMICTYPE-150]
+ _ = x[OTAILCALL-151]
+ _ = x[OGETG-152]
+ _ = x[OGETCALLERPC-153]
+ _ = x[OGETCALLERSP-154]
+ _ = x[OEND-155]
}
-const _Op_name = "XXXNAMENONAMETYPELITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVIDATACONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERSTRINGHEADERRECOVERRECOVERFPRECVRUNESTRSELRECV2REALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEUNSAFESLICEDATAUNSAFESTRINGUNSAFESTRINGDATAMETHEXPRMETHVALUEBLOCKBREAKCASECONTINUEDEFERFALLFORGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTINLCALLEFACEITABIDATASPTRCFUNCCHECKNILRESULTINLMARKLINKSYMOFFSETJUMPTABLEDYNAMICDOTTYPEDYNAMICDOTTYPE2DYNAMICTYPETAILCALLGETGGETCALLERPCGETCALLERSPEND"
+const _Op_name = "XXXNAMENONAMETYPELITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCAPCLEARCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVIDATACONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERSTRINGHEADERRECOVERRECOVERFPRECVRUNESTRSELRECV2REALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEUNSAFESLICEDATAUNSAFESTRINGUNSAFESTRINGDATAMETHEXPRMETHVALUEBLOCKBREAKCASECONTINUEDEFERFALLFORGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTINLCALLEFACEITABIDATASPTRCFUNCCHECKNILRESULTINLMARKLINKSYMOFFSETJUMPTABLEDYNAMICDOTTYPEDYNAMICDOTTYPE2DYNAMICTYPETAILCALLGETGGETCALLERPCGETCALLERSPEND"
-var _Op_index = [...]uint16{0, 3, 7, 13, 17, 24, 27, 30, 33, 35, 38, 44, 48, 54, 60, 69, 81, 90, 99, 111, 120, 129, 141, 143, 146, 156, 163, 170, 177, 181, 185, 193, 201, 210, 213, 218, 225, 232, 238, 247, 255, 263, 269, 273, 282, 291, 298, 302, 305, 312, 320, 327, 333, 336, 342, 349, 357, 361, 368, 376, 378, 380, 382, 384, 386, 388, 393, 398, 406, 409, 418, 421, 425, 433, 440, 449, 462, 465, 468, 471, 474, 477, 480, 486, 489, 492, 498, 502, 505, 509, 514, 519, 525, 530, 534, 539, 547, 555, 561, 570, 581, 593, 600, 609, 613, 620, 628, 632, 636, 643, 650, 658, 664, 673, 684, 699, 711, 727, 735, 744, 749, 754, 758, 766, 771, 775, 778, 782, 784, 789, 791, 796, 802, 808, 814, 820, 828, 835, 840, 844, 849, 853, 858, 866, 872, 879, 892, 901, 915, 930, 941, 949, 953, 964, 975, 978}
+var _Op_index = [...]uint16{0, 3, 7, 13, 17, 24, 27, 30, 33, 35, 38, 44, 48, 54, 60, 69, 81, 90, 99, 111, 120, 129, 141, 143, 146, 156, 163, 170, 177, 181, 185, 193, 201, 210, 213, 218, 223, 230, 237, 243, 252, 260, 268, 274, 278, 287, 296, 303, 307, 310, 317, 325, 332, 338, 341, 347, 354, 362, 366, 373, 381, 383, 385, 387, 389, 391, 393, 398, 403, 411, 414, 423, 426, 430, 438, 445, 454, 467, 470, 473, 476, 479, 482, 485, 491, 494, 497, 503, 507, 510, 514, 519, 524, 530, 535, 539, 544, 552, 560, 566, 575, 586, 598, 605, 614, 618, 625, 633, 637, 641, 648, 655, 663, 669, 678, 689, 704, 716, 732, 740, 749, 754, 759, 763, 771, 776, 780, 783, 787, 789, 794, 796, 801, 807, 813, 819, 825, 833, 840, 845, 849, 854, 858, 863, 871, 877, 884, 897, 906, 920, 935, 946, 954, 958, 969, 980, 983}
func (i Op) String() string {
if i >= Op(len(_Op_index)-1) {
diff --git a/src/cmd/compile/internal/typecheck/const.go b/src/cmd/compile/internal/typecheck/const.go
index edc399f..26a3753 100644
--- a/src/cmd/compile/internal/typecheck/const.go
+++ b/src/cmd/compile/internal/typecheck/const.go
@@ -743,6 +743,7 @@
ir.OCALLINTER,
ir.OCALLMETH,
ir.OCAP,
+ ir.OCLEAR,
ir.OCLOSE,
ir.OCOMPLEX,
ir.OCOPY,
diff --git a/src/cmd/compile/internal/typecheck/func.go b/src/cmd/compile/internal/typecheck/func.go
index 065007b..f64523c 100644
--- a/src/cmd/compile/internal/typecheck/func.go
+++ b/src/cmd/compile/internal/typecheck/func.go
@@ -260,7 +260,7 @@
n.SetTypecheck(0) // re-typechecking new op is OK, not a loop
return typecheck(n, top)
- case ir.OCAP, ir.OCLOSE, ir.OIMAG, ir.OLEN, ir.OPANIC, ir.OREAL, ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:
+ case ir.OCAP, ir.OCLEAR, ir.OCLOSE, ir.OIMAG, ir.OLEN, ir.OPANIC, ir.OREAL, ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:
typecheckargs(n)
fallthrough
case ir.ONEW, ir.OALIGNOF, ir.OOFFSETOF, ir.OSIZEOF:
@@ -441,6 +441,28 @@
return n
}
+// tcClear typechecks an OCLEAR node.
+func tcClear(n *ir.UnaryExpr) ir.Node {
+ n.X = Expr(n.X)
+ n.X = DefaultLit(n.X, nil)
+ l := n.X
+ t := l.Type()
+ if t == nil {
+ n.SetType(nil)
+ return n
+ }
+
+ switch {
+ case t.IsMap(), t.IsSlice():
+ default:
+ base.Errorf("invalid operation: %v (argument must be a map or slice)", n)
+ n.SetType(nil)
+ return n
+ }
+
+ return n
+}
+
// tcClose typechecks an OCLOSE node.
func tcClose(n *ir.UnaryExpr) ir.Node {
n.X = Expr(n.X)
diff --git a/src/cmd/compile/internal/typecheck/stmt.go b/src/cmd/compile/internal/typecheck/stmt.go
index 5eeab41..2af6c26 100644
--- a/src/cmd/compile/internal/typecheck/stmt.go
+++ b/src/cmd/compile/internal/typecheck/stmt.go
@@ -273,6 +273,7 @@
case ir.OCALLINTER,
ir.OCALLMETH,
ir.OCALLFUNC,
+ ir.OCLEAR,
ir.OCLOSE,
ir.OCOPY,
ir.ODELETE,
diff --git a/src/cmd/compile/internal/typecheck/typecheck.go b/src/cmd/compile/internal/typecheck/typecheck.go
index ea49e76..b06b9d9 100644
--- a/src/cmd/compile/internal/typecheck/typecheck.go
+++ b/src/cmd/compile/internal/typecheck/typecheck.go
@@ -336,7 +336,7 @@
case ir.OAPPEND:
// Must be used (and not BinaryExpr/UnaryExpr).
isStmt = false
- case ir.OCLOSE, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN:
+ case ir.OCLEAR, ir.OCLOSE, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN:
// Must not be used.
isExpr = false
isStmt = true
@@ -621,6 +621,10 @@
n := n.(*ir.BinaryExpr)
return tcComplex(n)
+ case ir.OCLEAR:
+ n := n.(*ir.UnaryExpr)
+ return tcClear(n)
+
case ir.OCLOSE:
n := n.(*ir.UnaryExpr)
return tcClose(n)
diff --git a/src/cmd/compile/internal/typecheck/universe.go b/src/cmd/compile/internal/typecheck/universe.go
index 828a8db..6c6a504 100644
--- a/src/cmd/compile/internal/typecheck/universe.go
+++ b/src/cmd/compile/internal/typecheck/universe.go
@@ -34,6 +34,7 @@
}{
{"append", ir.OAPPEND},
{"cap", ir.OCAP},
+ {"clear", ir.OCLEAR},
{"close", ir.OCLOSE},
{"complex", ir.OCOMPLEX},
{"copy", ir.OCOPY},
diff --git a/src/cmd/compile/internal/walk/builtin.go b/src/cmd/compile/internal/walk/builtin.go
index 4c5ee9b..3c85b19 100644
--- a/src/cmd/compile/internal/walk/builtin.go
+++ b/src/cmd/compile/internal/walk/builtin.go
@@ -130,6 +130,18 @@
return s
}
+// walkClear walks an OCLEAR node.
+func walkClear(n *ir.UnaryExpr) ir.Node {
+ typ := n.X.Type()
+ switch {
+ case typ.IsSlice():
+ return arrayClear(n.X.Pos(), n.X, nil)
+ case typ.IsMap():
+ return mapClear(n.X, reflectdata.TypePtrAt(n.X.Pos(), n.X.Type()))
+ }
+ panic("unreachable")
+}
+
// walkClose walks an OCLOSE node.
func walkClose(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
// cannot use chanfn - closechan takes any, not chan any
diff --git a/src/cmd/compile/internal/walk/expr.go b/src/cmd/compile/internal/walk/expr.go
index 24fe0d0..6f4a533 100644
--- a/src/cmd/compile/internal/walk/expr.go
+++ b/src/cmd/compile/internal/walk/expr.go
@@ -279,6 +279,10 @@
case ir.OCOPY:
return walkCopy(n.(*ir.BinaryExpr), init, base.Flag.Cfg.Instrumenting && !base.Flag.CompilingRuntime)
+ case ir.OCLEAR:
+ n := n.(*ir.UnaryExpr)
+ return walkClear(n)
+
case ir.OCLOSE:
n := n.(*ir.UnaryExpr)
return walkClose(n, init)
diff --git a/src/cmd/compile/internal/walk/order.go b/src/cmd/compile/internal/walk/order.go
index d6712ae..b6b277c 100644
--- a/src/cmd/compile/internal/walk/order.go
+++ b/src/cmd/compile/internal/walk/order.go
@@ -740,7 +740,7 @@
}
}
- case ir.OCHECKNIL, ir.OCLOSE, ir.OPANIC, ir.ORECV:
+ case ir.OCHECKNIL, ir.OCLEAR, ir.OCLOSE, ir.OPANIC, ir.ORECV:
n := n.(*ir.UnaryExpr)
t := o.markTemp()
n.X = o.expr(n.X, nil)
diff --git a/src/cmd/compile/internal/walk/range.go b/src/cmd/compile/internal/walk/range.go
index 64af26b..67c13a8 100644
--- a/src/cmd/compile/internal/walk/range.go
+++ b/src/cmd/compile/internal/walk/range.go
@@ -13,6 +13,7 @@
"cmd/compile/internal/ssagen"
"cmd/compile/internal/typecheck"
"cmd/compile/internal/types"
+ "cmd/internal/src"
"cmd/internal/sys"
)
@@ -38,7 +39,7 @@
// the returned node.
func walkRange(nrange *ir.RangeStmt) ir.Node {
if isMapClear(nrange) {
- return mapClear(nrange)
+ return mapRangeClear(nrange)
}
nfor := ir.NewForStmt(nrange.Pos(), nil, nil, nil, nil)
@@ -77,7 +78,7 @@
base.Fatalf("walkRange")
case types.TARRAY, types.TSLICE, types.TPTR: // TPTR is pointer-to-array
- if nn := arrayClear(nrange, v1, v2, a); nn != nil {
+ if nn := arrayRangeClear(nrange, v1, v2, a); nn != nil {
base.Pos = lno
return nn
}
@@ -437,18 +438,23 @@
return true
}
-// mapClear constructs a call to runtime.mapclear for the map m.
-func mapClear(nrange *ir.RangeStmt) ir.Node {
+// mapRangeClear constructs a call to runtime.mapclear for the map range idiom.
+func mapRangeClear(nrange *ir.RangeStmt) ir.Node {
m := nrange.X
origPos := ir.SetPos(m)
defer func() { base.Pos = origPos }()
+ return mapClear(m, reflectdata.RangeMapRType(base.Pos, nrange))
+}
+
+// mapClear constructs a call to runtime.mapclear for the map m.
+func mapClear(m, rtyp ir.Node) ir.Node {
t := m.Type()
// instantiate mapclear(typ *type, hmap map[any]any)
fn := typecheck.LookupRuntime("mapclear")
fn = typecheck.SubstArgTypes(fn, t.Key(), t.Elem())
- n := mkcallstmt1(fn, reflectdata.RangeMapRType(base.Pos, nrange), m)
+ n := mkcallstmt1(fn, rtyp, m)
return walkStmt(typecheck.Stmt(n))
}
@@ -463,7 +469,7 @@
// in which the evaluation of a is side-effect-free.
//
// Parameters are as in walkRange: "for v1, v2 = range a".
-func arrayClear(loop *ir.RangeStmt, v1, v2, a ir.Node) ir.Node {
+func arrayRangeClear(loop *ir.RangeStmt, v1, v2, a ir.Node) ir.Node {
if base.Flag.N != 0 || base.Flag.Cfg.Instrumenting {
return nil
}
@@ -496,8 +502,17 @@
return nil
}
- elemsize := typecheck.RangeExprType(loop.X.Type()).Elem().Size()
- if elemsize <= 0 || !ir.IsZero(stmt.Y) {
+ if !ir.IsZero(stmt.Y) {
+ return nil
+ }
+
+ return arrayClear(stmt.Pos(), a, loop)
+}
+
+// arrayClear constructs a call to runtime.memclr for fast zeroing of slices and arrays.
+func arrayClear(wbPos src.XPos, a ir.Node, nrange *ir.RangeStmt) ir.Node {
+ elemsize := typecheck.RangeExprType(a.Type()).Elem().Size()
+ if elemsize <= 0 {
return nil
}
@@ -527,7 +542,7 @@
var fn ir.Node
if a.Type().Elem().HasPointers() {
// memclrHasPointers(hp, hn)
- ir.CurFunc.SetWBPos(stmt.Pos())
+ ir.CurFunc.SetWBPos(wbPos)
fn = mkcallstmt("memclrHasPointers", hp, hn)
} else {
// memclrNoHeapPointers(hp, hn)
@@ -536,10 +551,11 @@
n.Body.Append(fn)
- // i = len(a) - 1
- v1 = ir.NewAssignStmt(base.Pos, v1, ir.NewBinaryExpr(base.Pos, ir.OSUB, ir.NewUnaryExpr(base.Pos, ir.OLEN, a), ir.NewInt(1)))
-
- n.Body.Append(v1)
+ // For array range clear, also set "i = len(a) - 1"
+ if nrange != nil {
+ idx := ir.NewAssignStmt(base.Pos, nrange.Key, ir.NewBinaryExpr(base.Pos, ir.OSUB, ir.NewUnaryExpr(base.Pos, ir.OLEN, a), ir.NewInt(1)))
+ n.Body.Append(idx)
+ }
n.Cond = typecheck.Expr(n.Cond)
n.Cond = typecheck.DefaultLit(n.Cond, nil)
diff --git a/src/cmd/compile/internal/walk/stmt.go b/src/cmd/compile/internal/walk/stmt.go
index ceee1b1..c6a03d2 100644
--- a/src/cmd/compile/internal/walk/stmt.go
+++ b/src/cmd/compile/internal/walk/stmt.go
@@ -39,6 +39,7 @@
ir.OAS2RECV,
ir.OAS2FUNC,
ir.OAS2MAPR,
+ ir.OCLEAR,
ir.OCLOSE,
ir.OCOPY,
ir.OCALLINTER,
diff --git a/test/clear.go b/test/clear.go
new file mode 100644
index 0000000..60ee4ec
--- /dev/null
+++ b/test/clear.go
@@ -0,0 +1,47 @@
+// run
+
+// Copyright 2022 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.
+
+package main
+
+import "math"
+
+func checkClearSlice() {
+ s := []int{1, 2, 3}
+ clear(s)
+ for i := range s {
+ if s[i] != 0 {
+ panic("clear not zeroing slice elem")
+ }
+ }
+
+ clear([]int{})
+}
+
+func checkClearMap() {
+ m1 := make(map[int]int)
+ m1[0] = 0
+ m1[1] = 1
+ clear(m1)
+ if len(m1) != 0 {
+ panic("m1 is not cleared")
+ }
+
+ // map contains NaN keys is also cleared.
+ m2 := make(map[float64]int)
+ m2[math.NaN()] = 1
+ m2[math.NaN()] = 1
+ clear(m2)
+ if len(m2) != 0 {
+ panic("m2 is not cleared")
+ }
+
+ clear(map[int]int{})
+}
+
+func main() {
+ checkClearSlice()
+ checkClearMap()
+}
