+++ /dev/null
-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package analysis
-
-// This file computes the channel "peers" relation over all pairs of
-// channel operations in the program. The peers are displayed in the
-// lower pane when a channel operation (make, <-, close) is clicked.
-
-// TODO(adonovan): handle calls to reflect.{Select,Recv,Send,Close} too,
-// then enable reflection in PTA.
-
-import (
- "fmt"
- "go/token"
- "go/types"
-
- "golang.org/x/tools/go/pointer"
- "golang.org/x/tools/go/ssa"
-)
-
-func (a *analysis) doChannelPeers(ptsets map[ssa.Value]pointer.Pointer) {
- addSendRecv := func(j *commJSON, op chanOp) {
- j.Ops = append(j.Ops, commOpJSON{
- Op: anchorJSON{
- Text: op.mode,
- Href: a.posURL(op.pos, op.len),
- },
- Fn: prettyFunc(nil, op.fn),
- })
- }
-
- // Build an undirected bipartite multigraph (binary relation)
- // of MakeChan ops and send/recv/close ops.
- //
- // TODO(adonovan): opt: use channel element types to partition
- // the O(n^2) problem into subproblems.
- aliasedOps := make(map[*ssa.MakeChan][]chanOp)
- opToMakes := make(map[chanOp][]*ssa.MakeChan)
- for _, op := range a.ops {
- // Combine the PT sets from all contexts.
- var makes []*ssa.MakeChan // aliased ops
- ptr, ok := ptsets[op.ch]
- if !ok {
- continue // e.g. channel op in dead code
- }
- for _, label := range ptr.PointsTo().Labels() {
- makechan, ok := label.Value().(*ssa.MakeChan)
- if !ok {
- continue // skip intrinsically-created channels for now
- }
- if makechan.Pos() == token.NoPos {
- continue // not possible?
- }
- makes = append(makes, makechan)
- aliasedOps[makechan] = append(aliasedOps[makechan], op)
- }
- opToMakes[op] = makes
- }
-
- // Now that complete relation is built, build links for ops.
- for _, op := range a.ops {
- v := commJSON{
- Ops: []commOpJSON{}, // (JS wants non-nil)
- }
- ops := make(map[chanOp]bool)
- for _, makechan := range opToMakes[op] {
- v.Ops = append(v.Ops, commOpJSON{
- Op: anchorJSON{
- Text: "made",
- Href: a.posURL(makechan.Pos()-token.Pos(len("make")),
- len("make")),
- },
- Fn: makechan.Parent().RelString(op.fn.Package().Pkg),
- })
- for _, op := range aliasedOps[makechan] {
- ops[op] = true
- }
- }
- for op := range ops {
- addSendRecv(&v, op)
- }
-
- // Add links for each aliased op.
- fi, offset := a.fileAndOffset(op.pos)
- fi.addLink(aLink{
- start: offset,
- end: offset + op.len,
- title: "show channel ops",
- onclick: fmt.Sprintf("onClickComm(%d)", fi.addData(v)),
- })
- }
- // Add links for makechan ops themselves.
- for makechan, ops := range aliasedOps {
- v := commJSON{
- Ops: []commOpJSON{}, // (JS wants non-nil)
- }
- for _, op := range ops {
- addSendRecv(&v, op)
- }
-
- fi, offset := a.fileAndOffset(makechan.Pos())
- fi.addLink(aLink{
- start: offset - len("make"),
- end: offset,
- title: "show channel ops",
- onclick: fmt.Sprintf("onClickComm(%d)", fi.addData(v)),
- })
- }
-}
-
-// -- utilities --------------------------------------------------------
-
-// chanOp abstracts an ssa.Send, ssa.Unop(ARROW), close(), or a SelectState.
-// Derived from cmd/guru/peers.go.
-type chanOp struct {
- ch ssa.Value
- mode string // sent|received|closed
- pos token.Pos
- len int
- fn *ssa.Function
-}
-
-// chanOps returns a slice of all the channel operations in the instruction.
-// Derived from cmd/guru/peers.go.
-func chanOps(instr ssa.Instruction) []chanOp {
- fn := instr.Parent()
- var ops []chanOp
- switch instr := instr.(type) {
- case *ssa.UnOp:
- if instr.Op == token.ARROW {
- // TODO(adonovan): don't assume <-ch; could be 'range ch'.
- ops = append(ops, chanOp{instr.X, "received", instr.Pos(), len("<-"), fn})
- }
- case *ssa.Send:
- ops = append(ops, chanOp{instr.Chan, "sent", instr.Pos(), len("<-"), fn})
- case *ssa.Select:
- for _, st := range instr.States {
- mode := "received"
- if st.Dir == types.SendOnly {
- mode = "sent"
- }
- ops = append(ops, chanOp{st.Chan, mode, st.Pos, len("<-"), fn})
- }
- case ssa.CallInstruction:
- call := instr.Common()
- if blt, ok := call.Value.(*ssa.Builtin); ok && blt.Name() == "close" {
- pos := instr.Common().Pos()
- ops = append(ops, chanOp{call.Args[0], "closed", pos - token.Pos(len("close")), len("close("), fn})
- }
- }
- return ops
-}
projects / dotfiles / .git / blobdiff