Add a tool to diff assembly files against OpenSSL.
Change-Id: I771c6c9d186c5ec0684696a3066a3e675691e60d
Reviewed-on: https://boringssl-review.googlesource.com/8516
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/util/diff_asm.go b/util/diff_asm.go
new file mode 100644
index 0000000..0a0888b
--- /dev/null
+++ b/util/diff_asm.go
@@ -0,0 +1,112 @@
+/* Copyright (c) 2016, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+package main
+
+import (
+ "flag"
+ "fmt"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "strings"
+ "syscall"
+)
+
+var (
+ boringsslDir = flag.String("boringssl", ".", "The path to the BoringSSL checkout.")
+ opensslDir = flag.String("openssl", filepath.Join("..", "openssl"), "The path to the OpenSSL checkout.")
+)
+
+func mapName(path string) string {
+ switch filepath.ToSlash(path) {
+ case "crypto/rand/asm/rdrand-x86_64.pl":
+ return ""
+ case "crypto/ec/asm/p256-x86_64-asm.pl":
+ return filepath.FromSlash("crypto/ec/asm/ecp_nistz256-x86_64.pl")
+ }
+ return path
+}
+
+func diff(from, to string) error {
+ cmd := exec.Command("diff", "-u", "--", from, to)
+ cmd.Stdout = os.Stdout
+ cmd.Stderr = os.Stderr
+ err := cmd.Run()
+ // diff returns exit code 1 if the files differ but it was otherwise
+ // successful.
+ if exitError, ok := err.(*exec.ExitError); ok && exitError.Sys().(syscall.WaitStatus).ExitStatus() == 1 {
+ return nil
+ }
+ return err
+}
+
+func main() {
+ flag.Usage = func() {
+ fmt.Fprintf(os.Stderr, "Usage: diff_asm [flag...] [filter...]\n")
+ fmt.Fprintf(os.Stderr, "Filter arguments limit to assembly files which match arguments.\n")
+ fmt.Fprintf(os.Stderr, "If not using a filter, piping to `diffstat` may be useful.\n\n")
+ flag.PrintDefaults()
+ }
+ flag.Parse()
+
+ // Find all the assembly files.
+ var files []string
+ err := filepath.Walk(*boringsslDir, func(path string, info os.FileInfo, err error) error {
+ if err != nil {
+ return nil
+ }
+
+ path, err = filepath.Rel(*boringsslDir, path)
+ if err != nil {
+ return err
+ }
+
+ dir := filepath.Base(filepath.Dir(path))
+ if !info.IsDir() && (dir == "asm" || dir == "perlasm") && strings.HasSuffix(filepath.Base(path), ".pl") {
+ files = append(files, path)
+ }
+
+ return nil
+ })
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "Error finding assembly: %s\n", err)
+ os.Exit(1)
+ }
+
+ for _, file := range files {
+ opensslFile := mapName(file)
+ if len(opensslFile) == 0 {
+ continue
+ }
+
+ if flag.NArg() > 0 {
+ var found bool
+ for _, arg := range flag.Args() {
+ if strings.Contains(file, arg) {
+ found = true
+ break
+ }
+ }
+ if !found {
+ continue
+ }
+ }
+
+ if err := diff(filepath.Join(*opensslDir, opensslFile), filepath.Join(*boringsslDir, file)); err != nil {
+ fmt.Fprintf(os.Stderr, "Error comparing %s: %s\n", file, err)
+ os.Exit(1)
+ }
+ }
+}
