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Keith Randall 2b8e60d464 runtime: make typehash match compiler generated hashes exactly
If typehash (used by reflect) does not match the built-in map's hash,
then problems occur. If a map is built using reflect, and then
assigned to a variable of map type, the hash function can change. That
causes very bad things.

This issue is rare. MapOf consults a cache of all types that occur in
the binary before making a new one. To make a true new map type (with
a hash function derived from typehash) that map type must not occur in
the binary anywhere. But to cause the bug, we need a variable of that
type in order to assign to it. The only way to make that work is to
use a named map type for the variable, so it is distinct from the
unnamed version that MapOf looks for.

Fixes #37716

Change-Id: I3537bfceca8cbfa1af84202f432f3c06953fe0ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/222357
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-10 16:26:59 +00:00
.github .github: add link to questions in ISSUE_TEMPLATE 2020-01-06 17:05:31 +00:00
api sync: add new Map method LoadAndDelete 2020-02-25 14:31:55 +00:00
doc doc/go1.14: document that unparsable URL in net/url.Error is now quoted 2020-03-06 14:41:22 +00:00
lib/time lib/time: update tz data to 2019c 2019-11-26 12:03:08 +00:00
misc misc/cgo/test: fix sigaltstack test on AIX 2020-03-04 17:33:06 +00:00
src runtime: make typehash match compiler generated hashes exactly 2020-03-10 16:26:59 +00:00
test runtime: make typehash match compiler generated hashes exactly 2020-03-10 16:26:59 +00:00
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AUTHORS A+C: change email address for Akhil Indurti 2019-09-09 15:30:38 +00:00
CONTRIBUTING.md all: restore changes from faulty merge/revert 2018-02-12 20:13:59 +00:00
CONTRIBUTORS CONTRIBUTORS: second round of updates for Go 1.14 2020-02-21 19:59:34 +00:00
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README.md

The Go Programming Language

Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.

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