Before this change, when DeepEqual checks values with cycle, it may
panic due to stack overflow.
Here is a sample to reproduce the issue.
makeCycleMap := func() interface{} {
cycleMap := map[string]interface{}{}
cycleMap["foo"] = cycleMap
return cycleMap
}
m1 := makeCycleMap()
m2 := makeCycleMap()
reflect.DeepEqual(m1, m2) // stack overflow
The root cause is that DeepEqual fails to cache interface values
in visited map, which is used to detect cycle. DeepEqual calls
CanAddr to check whether a value should be cached or not. However,
all values referenced by interface don't have flagAddr thus all these
values are not cached.
THe fix is to remove CanAddr calls and use underlying ptr in value
directly. As ptr is only read-only in DeepEqual for caching, it's
safe to do so. We don't use UnsafeAddr this time, because this method
panics when CanAddr returns false.
Fixes#33907
Change-Id: I2aa88cc060a2c2192b1d34c129c0aad4bd5597e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/191940
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The meaning of DeepEqual has never been specified.
Do that.
Also fix bug involving maps with NaN keys.
Except for the map bug fix, there should be no semantic changes here.
Fixes#12025.
Change-Id: Ied562cf543a22ec645d42bdb9b41d451c16b1f21
Reviewed-on: https://go-review.googlesource.com/17450
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
This is more correct with respect to garbage collection.
I don't know of any specific failures it could cause today.
Change-Id: I7eed6a06d2f281051199e79e4a9913aa8360ded7
Reviewed-on: https://go-review.googlesource.com/14137
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Huan Du
Zhou Peng
Ian Lance Taylor
Russ Cox
Brad Fitzpatrick