pkg/corpus: a separate package for the corpus functionality

pkg/fuzzer and syz-manager have a common corpus functionality that can
be well be unified.

Create a separate pkg/corpus package that would be used by both of them.
It will simplify further work of moving pkg/fuzzer to the host.

1 files changed, 41 insertions, 0 deletions

diff --git a/pkg/corpus/minimize.go b/pkg/corpus/minimize.go
new file mode 100644
index 000000000..b47816ccf
--- /dev/null
+++ b/pkg/corpus/minimize.go
@@ -0,0 +1,41 @@
+// Copyright 2024 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package corpus
+
+import (
+	"sort"
+
+	"github.com/google/syzkaller/pkg/signal"
+)
+
+func (corpus *Corpus) Minimize(cover bool) {
+	corpus.mu.Lock()
+	defer corpus.mu.Unlock()
+
+	inputs := make([]signal.Context, 0, len(corpus.progs))
+	for _, inp := range corpus.progs {
+		inputs = append(inputs, signal.Context{
+			Signal:  inp.Signal,
+			Context: inp,
+		})
+	}
+
+	// Note: inputs are unsorted (based on map iteration).
+	// This gives some intentional non-determinism during minimization.
+	// However, we want to give preference to non-squashed inputs,
+	// so let's sort by this criteria.
+	sort.SliceStable(inputs, func(i, j int) bool {
+		firstAny := inputs[i].Context.(*Item).HasAny
+		secondAny := inputs[j].Context.(*Item).HasAny
+		return !firstAny && secondAny
+	})
+
+	corpus.progs = make(map[string]*Item)
+	corpus.ProgramsList = ProgramsList{}
+	for _, ctx := range signal.Minimize(inputs) {
+		inp := ctx.(*Item)
+		corpus.progs[inp.Sig] = inp
+		corpus.saveProgram(inp.Prog, inp.Signal)
+	}
+}