1 files changed, 73 insertions, 0 deletions
diff --git a/vendor/honnef.co/go/tools/staticcheck/vrp/channel.go b/vendor/honnef.co/go/tools/staticcheck/vrp/channel.go
new file mode 100644
index 0000000..c8fbacb
--- /dev/null
+++ b/vendor/honnef.co/go/tools/staticcheck/vrp/channel.go
@@ -0,0 +1,73 @@
+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) }