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mirror of https://github.com/golang/go synced 2024-11-18 15:34:53 -07:00
go/oracle/callers.go
Alan Donovan e5d15a9781 go.tools/go/pointer: add intrinsic for time.startTimer, which is implemented in C.
Without it, no value appears to be sent on NewTicker/NewTimer channels.

+ test

Also:
- add (callgraph.Edge).{Description,Pos} convenience methods
  to simplify client code when Site==nil.

LGTM=gri
R=gri, friestein68503
CC=golang-codereviews
https://golang.org/cl/112610043
2014-07-22 18:30:06 -04:00

83 lines
2.1 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 (
"fmt"
"go/token"
"code.google.com/p/go.tools/go/callgraph"
"code.google.com/p/go.tools/go/ssa"
"code.google.com/p/go.tools/oracle/serial"
)
// Callers reports the possible callers of the function
// immediately enclosing the specified source location.
//
func callers(o *Oracle, qpos *QueryPos) (queryResult, error) {
pkg := o.prog.Package(qpos.info.Pkg)
if pkg == nil {
return nil, fmt.Errorf("no SSA package")
}
if !ssa.HasEnclosingFunction(pkg, qpos.path) {
return nil, fmt.Errorf("this position is not inside a function")
}
buildSSA(o)
target := ssa.EnclosingFunction(pkg, qpos.path)
if target == nil {
return nil, fmt.Errorf("no SSA function built for this location (dead code?)")
}
// Run the pointer analysis, recording each
// call found to originate from target.
o.ptaConfig.BuildCallGraph = true
cg := ptrAnalysis(o).CallGraph
cg.DeleteSyntheticNodes()
edges := cg.CreateNode(target).In
// TODO(adonovan): sort + dedup calls to ensure test determinism.
return &callersResult{
target: target,
callgraph: cg,
edges: edges,
}, nil
}
type callersResult struct {
target *ssa.Function
callgraph *callgraph.Graph
edges []*callgraph.Edge
}
func (r *callersResult) display(printf printfFunc) {
root := r.callgraph.Root
if r.edges == nil {
printf(r.target, "%s is not reachable in this program.", r.target)
} else {
printf(r.target, "%s is called from these %d sites:", r.target, len(r.edges))
for _, edge := range r.edges {
if edge.Caller == root {
printf(r.target, "the root of the call graph")
} else {
printf(edge, "\t%s from %s", edge.Description(), edge.Caller.Func)
}
}
}
}
func (r *callersResult) toSerial(res *serial.Result, fset *token.FileSet) {
var callers []serial.Caller
for _, edge := range r.edges {
callers = append(callers, serial.Caller{
Caller: edge.Caller.Func.String(),
Pos: fset.Position(edge.Pos()).String(),
Desc: edge.Description(),
})
}
res.Callers = callers
}