status-go/vendor/honnef.co/go/tools/staticcheck/vrp/channel.go

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2019-11-25 20:16:00 +00:00
package vrp
import (
"fmt"
"honnef.co/go/tools/ssa"
)
type ChannelInterval struct {
Size IntInterval
}
func (c ChannelInterval) Union(other Range) Range {
i, ok := other.(ChannelInterval)
if !ok {
i = ChannelInterval{EmptyIntInterval}
}
if c.Size.Empty() || !c.Size.IsKnown() {
return i
}
if i.Size.Empty() || !i.Size.IsKnown() {
return c
}
return ChannelInterval{
Size: c.Size.Union(i.Size).(IntInterval),
}
}
func (c ChannelInterval) String() string {
return c.Size.String()
}
func (c ChannelInterval) IsKnown() bool {
return c.Size.IsKnown()
}
type MakeChannelConstraint struct {
aConstraint
Buffer ssa.Value
}
type ChannelChangeTypeConstraint struct {
aConstraint
X ssa.Value
}
func NewMakeChannelConstraint(buffer, y ssa.Value) Constraint {
return &MakeChannelConstraint{NewConstraint(y), buffer}
}
func NewChannelChangeTypeConstraint(x, y ssa.Value) Constraint {
return &ChannelChangeTypeConstraint{NewConstraint(y), x}
}
func (c *MakeChannelConstraint) Operands() []ssa.Value { return []ssa.Value{c.Buffer} }
func (c *ChannelChangeTypeConstraint) Operands() []ssa.Value { return []ssa.Value{c.X} }
func (c *MakeChannelConstraint) String() string {
return fmt.Sprintf("%s = make(chan, %s)", c.Y().Name(), c.Buffer.Name())
}
func (c *ChannelChangeTypeConstraint) String() string {
return fmt.Sprintf("%s = changetype(%s)", c.Y().Name(), c.X.Name())
}
func (c *MakeChannelConstraint) Eval(g *Graph) Range {
i, ok := g.Range(c.Buffer).(IntInterval)
if !ok {
return ChannelInterval{NewIntInterval(NewZ(0), PInfinity)}
}
if i.Lower.Sign() == -1 {
i.Lower = NewZ(0)
}
return ChannelInterval{i}
}
func (c *ChannelChangeTypeConstraint) Eval(g *Graph) Range { return g.Range(c.X) }