Example #1
0
func ruleHash(target *core.BuildTarget, runtime bool) []byte {
	h := sha1.New()
	h.Write([]byte(target.Label.String()))
	for _, dep := range target.DeclaredDependencies() {
		h.Write([]byte(dep.String()))
	}
	for _, vis := range target.Visibility {
		h.Write([]byte(vis.String())) // Doesn't strictly affect the output, but best to be safe.
	}
	for _, hsh := range target.Hashes {
		h.Write([]byte(hsh))
	}
	for _, source := range target.AllSources() {
		h.Write([]byte(source.String()))
	}
	for _, out := range target.DeclaredOutputs() {
		h.Write([]byte(out))
	}
	for _, licence := range target.Licences {
		h.Write([]byte(licence))
	}
	for _, output := range target.TestOutputs {
		h.Write([]byte(output))
	}
	for _, output := range target.OptionalOutputs {
		h.Write([]byte(output))
	}
	for _, label := range target.Labels {
		h.Write([]byte(label))
	}
	hashBool(h, target.IsBinary)
	hashBool(h, target.IsTest)

	// Note that we only hash the current command here; whatever's set in commands that we're not going
	// to run is uninteresting to us.
	h.Write([]byte(target.GetCommand()))

	if runtime {
		// Similarly, we only hash the current command here again.
		h.Write([]byte(target.GetTestCommand()))
		for _, datum := range target.Data {
			h.Write([]byte(datum.String()))
		}
		hashBool(h, target.Containerise)
		if target.ContainerSettings != nil {
			e := gob.NewEncoder(h)
			if err := e.Encode(target.ContainerSettings); err != nil {
				panic(err)
			}
		}
		if target.Containerise {
			h.Write(core.State.Hashes.Containerisation)
		}
	}

	hashBool(h, target.NeedsTransitiveDependencies)
	hashBool(h, target.OutputIsComplete)
	// Should really not be conditional here, but we don't want adding the new flag to
	// change the hash of every single other target everywhere.
	// Might consider removing this the next time we peturb the hashing strategy.
	if target.Stamp {
		hashBool(h, target.Stamp)
	}
	for _, require := range target.Requires {
		h.Write([]byte(require))
	}
	// Indeterminate iteration order, yay...
	languages := []string{}
	for k := range target.Provides {
		languages = append(languages, k)
	}
	sort.Strings(languages)
	for _, lang := range languages {
		h.Write([]byte(lang))
		h.Write([]byte(target.Provides[lang].String()))
	}
	// Obviously we don't include the code pointer because it's a pointer.
	h.Write(target.PreBuildHash)
	h.Write(target.PostBuildHash)
	return h.Sum(nil)
}