open-nomad/vendor/honnef.co/go/tools/ir/irutil/visit.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

80 lines
2 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 irutil // import "honnef.co/go/tools/ir/irutil"
import "honnef.co/go/tools/ir"
// This file defines utilities for visiting the IR of
// a Program.
//
// TODO(adonovan): test coverage.
// AllFunctions finds and returns the set of functions potentially
// needed by program prog, as determined by a simple linker-style
// reachability algorithm starting from the members and method-sets of
// each package. The result may include anonymous functions and
// synthetic wrappers.
//
// Precondition: all packages are built.
//
func AllFunctions(prog *ir.Program) map[*ir.Function]bool {
visit := visitor{
prog: prog,
seen: make(map[*ir.Function]bool),
}
visit.program()
return visit.seen
}
type visitor struct {
prog *ir.Program
seen map[*ir.Function]bool
}
func (visit *visitor) program() {
for _, pkg := range visit.prog.AllPackages() {
for _, mem := range pkg.Members {
if fn, ok := mem.(*ir.Function); ok {
visit.function(fn)
}
}
}
for _, T := range visit.prog.RuntimeTypes() {
mset := visit.prog.MethodSets.MethodSet(T)
for i, n := 0, mset.Len(); i < n; i++ {
visit.function(visit.prog.MethodValue(mset.At(i)))
}
}
}
func (visit *visitor) function(fn *ir.Function) {
if !visit.seen[fn] {
visit.seen[fn] = true
var buf [10]*ir.Value // avoid alloc in common case
for _, b := range fn.Blocks {
for _, instr := range b.Instrs {
for _, op := range instr.Operands(buf[:0]) {
if fn, ok := (*op).(*ir.Function); ok {
visit.function(fn)
}
}
}
}
}
}
// MainPackages returns the subset of the specified packages
// named "main" that define a main function.
// The result may include synthetic "testmain" packages.
func MainPackages(pkgs []*ir.Package) []*ir.Package {
var mains []*ir.Package
for _, pkg := range pkgs {
if pkg.Pkg.Name() == "main" && pkg.Func("main") != nil {
mains = append(mains, pkg)
}
}
return mains
}