Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

go/types, types2: verify stateMask transitions in debug mode

Browse source 
Recently, we've changed the representation of Named type state from
an integer to a bit mask, which is a bit more complicated. To make
sure we uphold state invariants, we are adding a verification step
on each state transition.

This uncovered a few places where we do not uphold the transition
invariants; those are patched in this CL.

Change-Id: I76569e4326b2d362d7a1f078641029ffb3dca531
Reviewed-on: https://go-review.googlesource.com/c/go/+/714241
Auto-Submit: Mark Freeman <markfreeman@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This commit is contained in:
Mark Freeman 2025-10-22 14:04:09 -04:00 • committed by Gopher Robot
parent 92decdcbaa
commit b2af92270f
2 changed files with 54 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

37
src/cmd/compile/internal/types2/named.go
View file

@ -215,7 +215,7 @@ func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
// All others:
// Effectively, nothing happens.
func (n *Named) unpack() *Named {
if n.stateHas(unpacked | lazyLoaded) { // avoid locking below
if n.stateHas(lazyLoaded | unpacked) { // avoid locking below
return n
}
@ -225,7 +225,7 @@ func (n *Named) unpack() *Named {
defer n.mu.Unlock()
// only atomic for consistency; we are holding the mutex
if n.stateHas(unpacked | lazyLoaded) {
if n.stateHas(lazyLoaded | unpacked) {
return n
}
@ -243,10 +243,10 @@ func (n *Named) unpack() *Named {
n.tparams = orig.tparams
if len(orig.methods) == 0 {
n.setState(unpacked | hasMethods) // nothing further to do
n.setState(lazyLoaded | unpacked | hasMethods) // nothing further to do
n.inst.ctxt = nil
} else {
n.setState(unpacked)
n.setState(lazyLoaded | unpacked)
}
return n
}
@ -275,19 +275,36 @@ func (n *Named) unpack() *Named {
}
}
n.setState(unpacked | hasMethods)
n.setState(lazyLoaded | unpacked | hasMethods)
return n
}
// stateHas atomically determines whether the current state includes any active bit in sm.
func (n *Named) stateHas(sm stateMask) bool {
return atomic.LoadUint32(&n.state_)&uint32(sm) != 0
func (n *Named) stateHas(m stateMask) bool {
return stateMask(atomic.LoadUint32(&n.state_))&m != 0
}
// setState atomically sets the current state to include each active bit in sm.
// Must only be called while holding n.mu.
func (n *Named) setState(sm stateMask) {
atomic.OrUint32(&n.state_, uint32(sm))
func (n *Named) setState(m stateMask) {
atomic.OrUint32(&n.state_, uint32(m))
// verify state transitions
if debug {
m := stateMask(atomic.LoadUint32(&n.state_))
u := m&unpacked != 0
// unpacked => lazyLoaded
if u {
assert(m&lazyLoaded != 0)
}
// hasMethods => unpacked
if m&hasMethods != 0 {
assert(u)
}
// hasUnder => unpacked
if m&hasUnder != 0 {
assert(u)
}
}
}
// newNamed is like NewNamed but with a *Checker receiver.
@ -503,7 +520,7 @@ func (t *Named) SetUnderlying(u Type) {
t.fromRHS = u
t.allowNilRHS = false
t.setState(unpacked | hasMethods) // TODO(markfreeman): Why hasMethods?
t.setState(lazyLoaded | unpacked | hasMethods) // TODO(markfreeman): Why hasMethods?
t.underlying = u
t.allowNilUnderlying = false

37
src/go/types/named.go
View file

@ -218,7 +218,7 @@ func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
// All others:
// Effectively, nothing happens.
func (n *Named) unpack() *Named {
if n.stateHas(unpacked | lazyLoaded) { // avoid locking below
if n.stateHas(lazyLoaded | unpacked) { // avoid locking below
return n
}
@ -228,7 +228,7 @@ func (n *Named) unpack() *Named {
defer n.mu.Unlock()
// only atomic for consistency; we are holding the mutex
if n.stateHas(unpacked | lazyLoaded) {
if n.stateHas(lazyLoaded | unpacked) {
return n
}
@ -246,10 +246,10 @@ func (n *Named) unpack() *Named {
n.tparams = orig.tparams
if len(orig.methods) == 0 {
n.setState(unpacked | hasMethods) // nothing further to do
n.setState(lazyLoaded | unpacked | hasMethods) // nothing further to do
n.inst.ctxt = nil
} else {
n.setState(unpacked)
n.setState(lazyLoaded | unpacked)
}
return n
}
@ -278,19 +278,36 @@ func (n *Named) unpack() *Named {
}
}
n.setState(unpacked | hasMethods)
n.setState(lazyLoaded | unpacked | hasMethods)
return n
}
// stateHas atomically determines whether the current state includes any active bit in sm.
func (n *Named) stateHas(sm stateMask) bool {
return atomic.LoadUint32(&n.state_)&uint32(sm) != 0
func (n *Named) stateHas(m stateMask) bool {
return stateMask(atomic.LoadUint32(&n.state_))&m != 0
}
// setState atomically sets the current state to include each active bit in sm.
// Must only be called while holding n.mu.
func (n *Named) setState(sm stateMask) {
atomic.OrUint32(&n.state_, uint32(sm))
func (n *Named) setState(m stateMask) {
atomic.OrUint32(&n.state_, uint32(m))
// verify state transitions
if debug {
m := stateMask(atomic.LoadUint32(&n.state_))
u := m&unpacked != 0
// unpacked => lazyLoaded
if u {
assert(m&lazyLoaded != 0)
}
// hasMethods => unpacked
if m&hasMethods != 0 {
assert(u)
}
// hasUnder => unpacked
if m&hasUnder != 0 {
assert(u)
}
}
}
// newNamed is like NewNamed but with a *Checker receiver.
@ -506,7 +523,7 @@ func (t *Named) SetUnderlying(u Type) {
t.fromRHS = u
t.allowNilRHS = false
t.setState(unpacked | hasMethods) // TODO(markfreeman): Why hasMethods?
t.setState(lazyLoaded | unpacked | hasMethods) // TODO(markfreeman): Why hasMethods?
t.underlying = u
t.allowNilUnderlying = false