internal/trace: add "command" to convert text traces to raw

This is primarily helpful for parsing traces dumped via CI.

cmd/dist doesn't like commands in std which are not actually part of the
Go distribution. So rather than using a real command, this is actually a
test which does the conversion.

Change-Id: I6a6a636c829a4acc0bce8cf7548105ad59d83c67
Reviewed-on: https://go-review.googlesource.com/c/go/+/716882
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/internal/trace/testtrace/helpers.go b/src/internal/trace/testtrace/helpers.go
index 50f6825bab5df94dbf2462004e20fcc0cbe4acaa..ef676a9a143e61b12fce607cbe8ddc21fed62872 100644 (file)
--- a/src/internal/trace/testtrace/helpers.go
+++ b/src/internal/trace/testtrace/helpers.go
@@ -37,6 +37,7 @@ func Dump(t *testing.T, testName string, traceBytes []byte, forceToFile bool) {
                        t.Logf("text trace too large to dump (%d bytes)", len(s))
                } else {
                        t.Log(s)
+                       t.Log("Convert this to a raw trace with `go test internal/trace/testtrace -covert in.tracetxt -out out.trace`")
                }
        } else {
                // We asked to dump the trace or failed. Write the trace to a file.

diff --git a/src/internal/trace/testtrace/helpers_test.go b/src/internal/trace/testtrace/helpers_test.go
new file mode 100644 (file)
index 0000000..3b874ac
--- /dev/null
+++ b/src/internal/trace/testtrace/helpers_test.go
@@ -0,0 +1,79 @@
+// Copyright 2025 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 testtrace
+
+import (
+       "flag"
+       "fmt"
+       "io"
+       "internal/trace/raw"
+       "os"
+       "testing"
+)
+
+var (
+       convert = flag.String("convert", "", "Path to trace text file to convert to binary format")
+       output = flag.String("out", "", "Output path for converted trace")
+)
+
+// TestConvertDump is not actually a test, it is a tool for converting trace
+// text dumps generated by Dump into the binary trace format. Set -convert and
+// -o to perform a converison.
+//
+//  go test internal/trace/testtrace -convert in.tracetxt -out out.trace
+//
+// This would be cleaner as a dedicated internal command rather than a test,
+// but cmd/dist does not handle internal (non-distributed) commands in std
+// well.
+func TestConvertDump(t *testing.T) {
+       if *convert == "" {
+               t.Skip("Set -convert to convert a trace text file")
+       }
+       if *output == "" {
+               t.Fatal("Set -o to specify conversion output")
+       }
+
+       if err := convertDump(*convert, *output); err != nil {
+               t.Error(err)
+       }
+}
+
+func convertDump(inPath, outPath string) error {
+       in, err := os.Open(inPath)
+       if err != nil {
+               return fmt.Errorf("error opening input: %v", err)
+       }
+       defer in.Close()
+
+       out, err := os.Create(outPath)
+       if err != nil {
+               return fmt.Errorf("error creating output: %v", err)
+       }
+       defer out.Close()
+
+       tr, err := raw.NewTextReader(in)
+       if err != nil {
+               return fmt.Errorf("error creating text reader: %v", err)
+       }
+       tw, err := raw.NewWriter(out, tr.Version())
+       if err != nil {
+               return fmt.Errorf("error creating raw writer: %v", err)
+       }
+
+       for {
+               ev, err := tr.ReadEvent()
+               if err == io.EOF {
+                       break
+               }
+               if err != nil {
+                       return fmt.Errorf("bad trace file: %v", err)
+               }
+               if err := tw.WriteEvent(ev); err != nil {
+                       return fmt.Errorf("failed to write trace bytes: %v", err)
+               }
+       }
+
+       return nil
+}