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runtime: fix getgcmask

bv.data is an array of uint32s but the code was using
offsets computed for an array of bytes.
Add a test for stack GC info.
Fixes #8531.

LGTM=rsc
R=golang-codereviews
CC=golang-codereviews, khr, rsc
https://golang.org/cl/124450043
This commit is contained in:
Dmitriy Vyukov 2014-08-15 22:36:12 +04:00
parent 7f40e5e6e5
commit c5e648d684
2 changed files with 39 additions and 19 deletions

View File

@ -12,24 +12,30 @@ import (
// TestGCInfo tests that various objects in heap, data and bss receive correct GC pointer type info.
func TestGCInfo(t *testing.T) {
verifyGCInfo(t, "bss ScalarPtr", &bssScalarPtr, infoScalarPtr)
verifyGCInfo(t, "bss PtrScalar", &bssPtrScalar, infoPtrScalar)
verifyGCInfo(t, "bss Complex", &bssComplex, infoComplex())
verifyGCInfo(t, "bss string", &bssString, infoString)
verifyGCInfo(t, "bss eface", &bssEface, infoEface)
verifyGCInfo(t, "bss ScalarPtr", &bssScalarPtr, nonStackInfo(infoScalarPtr))
verifyGCInfo(t, "bss PtrScalar", &bssPtrScalar, nonStackInfo(infoPtrScalar))
verifyGCInfo(t, "bss Complex", &bssComplex, nonStackInfo(infoComplex()))
verifyGCInfo(t, "bss string", &bssString, nonStackInfo(infoString))
verifyGCInfo(t, "bss eface", &bssEface, nonStackInfo(infoEface))
verifyGCInfo(t, "data ScalarPtr", &dataScalarPtr, infoScalarPtr)
verifyGCInfo(t, "data PtrScalar", &dataPtrScalar, infoPtrScalar)
verifyGCInfo(t, "data Complex", &dataComplex, infoComplex())
verifyGCInfo(t, "data string", &dataString, infoString)
verifyGCInfo(t, "data eface", &dataEface, infoEface)
verifyGCInfo(t, "data ScalarPtr", &dataScalarPtr, nonStackInfo(infoScalarPtr))
verifyGCInfo(t, "data PtrScalar", &dataPtrScalar, nonStackInfo(infoPtrScalar))
verifyGCInfo(t, "data Complex", &dataComplex, nonStackInfo(infoComplex()))
verifyGCInfo(t, "data string", &dataString, nonStackInfo(infoString))
verifyGCInfo(t, "data eface", &dataEface, nonStackInfo(infoEface))
verifyGCInfo(t, "stack ScalarPtr", new(ScalarPtr), infoScalarPtr)
verifyGCInfo(t, "stack PtrScalar", new(PtrScalar), infoPtrScalar)
verifyGCInfo(t, "stack Complex", new(Complex), infoComplex())
verifyGCInfo(t, "stack string", new(string), infoString)
verifyGCInfo(t, "stack eface", new(interface{}), infoEface)
for i := 0; i < 3; i++ {
verifyGCInfo(t, "heap ScalarPtr", escape(new(ScalarPtr)), infoScalarPtr)
verifyGCInfo(t, "heap PtrScalar", escape(new(PtrScalar)), infoPtrScalar)
verifyGCInfo(t, "heap Complex", escape(new(Complex)), infoComplex())
verifyGCInfo(t, "heap string", escape(new(string)), infoString)
verifyGCInfo(t, "heap eface", escape(new(interface{})), infoEface)
verifyGCInfo(t, "heap ScalarPtr", escape(new(ScalarPtr)), nonStackInfo(infoScalarPtr))
verifyGCInfo(t, "heap PtrScalar", escape(new(PtrScalar)), nonStackInfo(infoPtrScalar))
verifyGCInfo(t, "heap Complex", escape(new(Complex)), nonStackInfo(infoComplex()))
verifyGCInfo(t, "heap string", escape(new(string)), nonStackInfo(infoString))
verifyGCInfo(t, "heap eface", escape(new(interface{})), nonStackInfo(infoEface))
}
}
@ -46,6 +52,20 @@ func verifyGCInfo(t *testing.T, name string, p interface{}, mask0 []byte) {
}
}
func nonStackInfo(mask []byte) []byte {
// BitsDead is replaced with BitsScalar everywhere except stacks.
mask1 := make([]byte, len(mask))
mw := false
for i, v := range mask {
if !mw && v == BitsDead {
v = BitsScalar
}
mw = !mw && v == BitsMultiWord
mask1[i] = v
}
return mask1
}
var gcinfoSink interface{}
func escape(p interface{}) interface{} {
@ -106,20 +126,20 @@ func infoComplex() []byte {
return []byte{
BitsPointer, BitsScalar, BitsScalar, BitsScalar,
BitsScalar, BitsScalar, BitsMultiWord, BitsSlice,
BitsScalar, BitsScalar, BitsScalar, BitsScalar,
BitsDead, BitsScalar, BitsScalar, BitsScalar,
BitsScalar, BitsMultiWord, BitsString,
}
case "amd64":
return []byte{
BitsPointer, BitsScalar, BitsScalar, BitsScalar,
BitsMultiWord, BitsSlice, BitsScalar, BitsScalar,
BitsMultiWord, BitsSlice, BitsDead, BitsScalar,
BitsScalar, BitsScalar, BitsMultiWord, BitsString,
}
case "amd64p32":
return []byte{
BitsPointer, BitsScalar, BitsScalar, BitsScalar,
BitsScalar, BitsScalar, BitsMultiWord, BitsSlice,
BitsScalar, BitsScalar, BitsScalar, BitsScalar,
BitsDead, BitsScalar, BitsScalar, BitsDead,
BitsScalar, BitsScalar, BitsMultiWord, BitsString,
}
default:

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@ -2087,7 +2087,7 @@ runtime·getgcmask(byte *p, Type *t, byte **mask, uintptr *len)
*mask = runtime·mallocgc(*len, nil, 0);
for(i = 0; i < n; i += PtrSize) {
off = (p+i-frame.varp+size)/PtrSize;
bits = (bv.data[off/PointersPerByte] >> ((off%PointersPerByte)*BitsPerPointer))&BitsMask;
bits = (bv.data[off*BitsPerPointer/32] >> ((off*BitsPerPointer)%32))&BitsMask;
(*mask)[i/PtrSize] = bits;
}
}