gotools/go/ssa/ssautil/switch.go

type ConstCase …

type TypeCase …

type Switch …

func (sw *Switch) String() string { … }

// Switches examines the control-flow graph of fn and returns the
// set of inferred value and type switches.  A value switch tests an
// ssa.Value for equality against two or more compile-time constant
// values.  Switches involving link-time constants (addresses) are
// ignored.  A type switch type-asserts an ssa.Value against two or
// more types.
//
// The switches are returned in dominance order.
//
// The resulting switches do not necessarily correspond to uses of the
// 'switch' keyword in the source: for example, a single source-level
// switch statement with non-constant cases may result in zero, one or
// many Switches, one per plural sequence of constant cases.
// Switches may even be inferred from if/else- or goto-based control flow.
// (In general, the control flow constructs of the source program
// cannot be faithfully reproduced from the SSA representation.)
func Switches(fn *ssa.Function) []Switch { … }

func valueSwitch(sw *Switch, k *ssa.Const, seen map[*ssa.BasicBlock]bool) { … }

func typeSwitch(sw *Switch, y ssa.Value, T types.Type, seen map[*ssa.BasicBlock]bool) { … }

// isComparisonBlock returns the operands (v, k) if a block ends with
// a comparison v==k, where k is a compile-time constant.
func isComparisonBlock(b *ssa.BasicBlock) (v ssa.Value, k *ssa.Const) { … }

// isTypeAssertBlock returns the operands (y, x, T) if a block ends with
// a type assertion "if y, ok := x.(T); ok {".
func isTypeAssertBlock(b *ssa.BasicBlock) (y, x ssa.Value, T types.Type) { … }