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go/oracle/callers.go
Alan Donovan 99b2441d95 go.tools/oracle: optionally restrict 'callgraph' query to a single package.
If a -pos argument is specified, a 'callgraph' query reports only the
functions within the query package.  This produces a far more manageable
amount of information, and because we don't need to package-qualify the
names, the result is easier to read.

Added tests:
- callgraph query with/without -pos
  (The test driver was extended to allow "nopos" queries.)
- callers and callees queries don't return wrappers

Also, in go/callgraph:
- (*Node).String, (*Edge).String
- (*Graph).DeleteSyntheticNodes eliminates synthetic wrapper functions,
  preserving topology.  Used in all four oracle "call*" queries.
- (*Graph).DeleteNode

LGTM=crawshaw
R=crawshaw
CC=golang-codereviews
https://golang.org/cl/66240044
2014-02-21 10:46:02 -05:00

88 lines
2.3 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.Site, "\t%s from %s", edge.Site.Common().Description(), edge.Caller.Func)
}
}
}
}
func (r *callersResult) toSerial(res *serial.Result, fset *token.FileSet) {
root := r.callgraph.Root
var callers []serial.Caller
for _, edge := range r.edges {
var c serial.Caller
c.Caller = edge.Caller.Func.String()
if edge.Caller == root {
c.Desc = "synthetic call"
} else {
c.Pos = fset.Position(edge.Site.Pos()).String()
c.Desc = edge.Site.Common().Description()
}
callers = append(callers, c)
}
res.Callers = callers
}