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go/oracle/callers.go
Alan Donovan afcda55b39 go/ssa: rename some API features (incompatible change)
Rename the following exported names:
	(*Program).BuildAll → Build
	(*Program).Method   → MethodValue
	Package.Object      → Pkg
Also:
	(*Function).pkgobj  → pkg

Change-Id: Iff7e6c240ebe6786ba759278ac0daa3d66698013
Reviewed-on: https://go-review.googlesource.com/14134
Reviewed-by: Robert Griesemer <gri@golang.org>
2015-08-31 22:20:12 +00:00

116 lines
2.8 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"
"golang.org/x/tools/go/callgraph"
"golang.org/x/tools/go/loader"
"golang.org/x/tools/go/ssa"
"golang.org/x/tools/go/ssa/ssautil"
"golang.org/x/tools/oracle/serial"
)
// Callers reports the possible callers of the function
// immediately enclosing the specified source location.
//
func callers(q *Query) error {
lconf := loader.Config{Build: q.Build}
if err := setPTAScope(&lconf, q.Scope); err != nil {
return err
}
// Load/parse/type-check the program.
lprog, err := lconf.Load()
if err != nil {
return err
}
q.Fset = lprog.Fset
qpos, err := parseQueryPos(lprog, q.Pos, false)
if err != nil {
return err
}
prog := ssautil.CreateProgram(lprog, 0)
ptaConfig, err := setupPTA(prog, lprog, q.PTALog, q.Reflection)
if err != nil {
return err
}
pkg := prog.Package(qpos.info.Pkg)
if pkg == nil {
return fmt.Errorf("no SSA package")
}
if !ssa.HasEnclosingFunction(pkg, qpos.path) {
return fmt.Errorf("this position is not inside a function")
}
// Defer SSA construction till after errors are reported.
prog.Build()
target := ssa.EnclosingFunction(pkg, qpos.path)
if target == nil {
return fmt.Errorf("no SSA function built for this location (dead code?)")
}
// TODO(adonovan): opt: if function is never address-taken, skip
// the pointer analysis. Just look for direct calls. This can
// be done in a single pass over the SSA.
// Run the pointer analysis, recording each
// call found to originate from target.
ptaConfig.BuildCallGraph = true
cg := ptrAnalysis(ptaConfig).CallGraph
cg.DeleteSyntheticNodes()
edges := cg.CreateNode(target).In
// TODO(adonovan): sort + dedup calls to ensure test determinism.
q.result = &callersResult{
target: target,
callgraph: cg,
edges: edges,
}
return 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
}