CC @golang/compiler.

https://github.com/google/perf_data_converter should be the way to do this, but there a couple of minor roadblocks:

1. perf_data_converter doesn't symbolize its output profile (it just contains PCs). That's not a fundamental problem, as pprof will symbolize profiles, so you could do something like pprof -proto converted.pprof > symbolized.pprof. But this leads to problem 2.
2. pprof symbolization doesn't set the Function.start_line field in the profiles, which Go's PGO requires. This should be a fairly small change to pprof to support, but it hasn't been done yet.

pprof symbolization doesn't set the Function.start_line field in the profiles, which Go's PGO requires. This should be a fairly small change to pprof to support, but it hasn't been done yet.

Do we need to create a separate issue in the pprof repo to add this functionality?

I filed google/pprof#823 for this, including a prototype implementation.

This made me realize one more tiny snag: the compiler is picky about the sample types reported by the profile (mostly to warn users if they try to use a heap profile or something), but the sample types selected by perf_to_profile aren't quite right. It is easy to change them [1], but we should probably just make the compiler less picky.

[1]

change_sample.go:

package main

import (
        "os"

        "github.com/google/pprof/profile"
)

func main() {
        p, _ := profile.Parse(os.Stdin)
        p.SampleType = []*profile.ValueType{
                {
                        Type: "event",
                        Unit: "count",
                },
                {
                        Type: "samples",
                        Unit: "count",
                },
        }
        p.Write(os.Stdout)
}

$ go run change_sample.go < perf.pprof > perf.changed.pprof