Initial commit: Go 1.23 release state

src/cmd/preprofile/main.go

@@ -0,0 +1,90 @@
+// Copyright 2023 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.
+
+// Preprofile creates an intermediate representation of a pprof profile for use
+// during PGO in the compiler. This transformation depends only on the profile
+// itself and is thus wasteful to perform in every invocation of the compiler.
+//
+// Usage:
+//
+//	go tool preprofile [-v] [-o output] -i input
+//
+//
+
+package main
+
+import (
+	"bufio"
+	"cmd/internal/objabi"
+	"cmd/internal/pgo"
+	"cmd/internal/telemetry/counter"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: go tool preprofile [-v] [-o output] -i input\n\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+var (
+	output = flag.String("o", "", "output file path")
+	input  = flag.String("i", "", "input pprof file path")
+)
+
+func preprocess(profileFile string, outputFile string) error {
+	f, err := os.Open(profileFile)
+	if err != nil {
+		return fmt.Errorf("error opening profile: %w", err)
+	}
+	defer f.Close()
+
+	r := bufio.NewReader(f)
+	d, err := pgo.FromPProf(r)
+	if err != nil {
+		return fmt.Errorf("error parsing profile: %w", err)
+	}
+
+	var out *os.File
+	if outputFile == "" {
+		out = os.Stdout
+	} else {
+		out, err = os.Create(outputFile)
+		if err != nil {
+			return fmt.Errorf("error creating output file: %w", err)
+		}
+		defer out.Close()
+	}
+
+	w := bufio.NewWriter(out)
+	if _, err := d.WriteTo(w); err != nil {
+		return fmt.Errorf("error writing output file: %w", err)
+	}
+
+	return nil
+}
+
+func main() {
+	objabi.AddVersionFlag()
+
+	log.SetFlags(0)
+	log.SetPrefix("preprofile: ")
+	counter.Open()
+
+	flag.Usage = usage
+	flag.Parse()
+	counter.Inc("preprofile/invocations")
+	counter.CountFlags("preprofile/flag:", *flag.CommandLine)
+	if *input == "" {
+		log.Print("Input pprof path required (-i)")
+		usage()
+	}
+
+	if err := preprocess(*input, *output); err != nil {
+		log.Fatal(err)
+	}
+}