mirror of
https://github.com/golang/go
synced 2024-11-18 19:14:40 -07:00
91 lines
2.4 KiB
Go
91 lines
2.4 KiB
Go
// Copyright 2013 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 oracle
|
|
|
|
import (
|
|
"code.google.com/p/go.tools/pointer"
|
|
"code.google.com/p/go.tools/ssa"
|
|
)
|
|
|
|
// Callstack displays an arbitrary path from a root of the callgraph
|
|
// to the function at the current position.
|
|
//
|
|
// The information may be misleading in a context-insensitive
|
|
// analysis. e.g. the call path X->Y->Z might be infeasible if Y never
|
|
// calls Z when it is called from X. TODO(adonovan): think about UI.
|
|
//
|
|
// TODO(adonovan): permit user to specify a starting point other than
|
|
// the analysis root.
|
|
//
|
|
func callstack(o *oracle) (queryResult, error) {
|
|
pkg := o.prog.Package(o.queryPkgInfo.Pkg)
|
|
if pkg == nil {
|
|
return nil, o.errorf(o.queryPath[0], "no SSA package")
|
|
}
|
|
|
|
if !ssa.HasEnclosingFunction(pkg, o.queryPath) {
|
|
return nil, o.errorf(o.queryPath[0], "this position is not inside a function")
|
|
}
|
|
|
|
buildSSA(o)
|
|
|
|
target := ssa.EnclosingFunction(pkg, o.queryPath)
|
|
if target == nil {
|
|
return nil, o.errorf(o.queryPath[0],
|
|
"no SSA function built for this location (dead code?)")
|
|
}
|
|
|
|
// Run the pointer analysis and build the complete call graph.
|
|
callgraph := make(pointer.CallGraph)
|
|
o.config.Call = callgraph.AddEdge
|
|
root := ptrAnalysis(o)
|
|
|
|
return &callstackResult{
|
|
target: target,
|
|
root: root,
|
|
callgraph: callgraph,
|
|
}, nil
|
|
}
|
|
|
|
type callstackResult struct {
|
|
target *ssa.Function
|
|
root pointer.CallGraphNode
|
|
callgraph pointer.CallGraph
|
|
|
|
seen map[pointer.CallGraphNode]bool // used by display
|
|
}
|
|
|
|
func (r *callstackResult) search(o *oracle, cgn pointer.CallGraphNode) bool {
|
|
if !r.seen[cgn] {
|
|
r.seen[cgn] = true
|
|
if cgn.Func() == r.target {
|
|
o.printf(o, "Found a call path from root to %s", r.target)
|
|
o.printf(r.target, "%s", r.target)
|
|
return true
|
|
}
|
|
for callee, site := range r.callgraph[cgn] {
|
|
if r.search(o, callee) {
|
|
o.printf(site, "%s from %s", site.Description(), cgn.Func())
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (r *callstackResult) display(o *oracle) {
|
|
// Show only an arbitrary path from a root to the current function.
|
|
// We use depth-first search.
|
|
|
|
r.seen = make(map[pointer.CallGraphNode]bool)
|
|
|
|
for toplevel := range r.callgraph[r.root] {
|
|
if r.search(o, toplevel) {
|
|
return
|
|
}
|
|
}
|
|
o.printf(r.target, "%s is unreachable in this analysis scope", r.target)
|
|
}
|