cmd/pprof: handle empty profile gracefully
The command "go tool pprof -top $GOROOT/bin/go /dev/null" now logs that
profile is empty instead of panicking.
Fixes #9207
Change-Id: I3d55c179277cb19ad52c8f24f1aca85db53ee08d
Reviewed-on: https://go-review.googlesource.com/2571
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/pprof/internal/driver/driver.go b/src/cmd/pprof/internal/driver/driver.go
index 9703baf..acb29d1 100644
--- a/src/cmd/pprof/internal/driver/driver.go
+++ b/src/cmd/pprof/internal/driver/driver.go
@@ -1013,6 +1013,10 @@
w = outputFile
}
+ if prof.Empty() {
+ return fmt.Errorf("profile is empty")
+ }
+
value, stype, unit := sampleFormat(prof, f)
o.SampleType = stype
rpt := report.New(prof, *o, value, unit)
diff --git a/src/cmd/pprof/internal/profile/profile.go b/src/cmd/pprof/internal/profile/profile.go
index 7ee58ee..5eb641f 100644
--- a/src/cmd/pprof/internal/profile/profile.go
+++ b/src/cmd/pprof/internal/profile/profile.go
@@ -565,3 +565,8 @@
}
return nil
}
+
+// Empty returns true if the profile contains no samples.
+func (p *Profile) Empty() bool {
+ return len(p.Sample) == 0
+}
diff --git a/src/cmd/pprof/internal/profile/profile_test.go b/src/cmd/pprof/internal/profile/profile_test.go
new file mode 100644
index 0000000..09b11a4
--- /dev/null
+++ b/src/cmd/pprof/internal/profile/profile_test.go
@@ -0,0 +1,24 @@
+// Copyright 2015 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 profile
+
+import (
+ "bytes"
+ "testing"
+)
+
+func TestEmptyProfile(t *testing.T) {
+ var buf bytes.Buffer
+ p, err := Parse(&buf)
+ if err != nil {
+ t.Error("Want no error, got", err)
+ }
+ if p == nil {
+ t.Fatal("Want a valid profile, got <nil>")
+ }
+ if !p.Empty() {
+ t.Errorf("Profile should be empty, got %#v", p)
+ }
+}
