cmd/go: look for tool build ID before hashing entire file
Also fix the key used to store the ID.
This is a significant speedup in cmd/go run time.
Change-Id: Ie4c2f945872204fe24118d2adb2163f498d4394e
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194257
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/libgo/go/cmd/go/internal/work/buildid.go b/libgo/go/cmd/go/internal/work/buildid.go
index 1f6d1e8..5ff9337 100644
--- a/libgo/go/cmd/go/internal/work/buildid.go
+++ b/libgo/go/cmd/go/internal/work/buildid.go
@@ -291,14 +291,19 @@
exe = lp
}
}
- if _, err := os.Stat(exe); err != nil {
- return "", fmt.Errorf("%s: can not find compiler %q: %v; output %q", name, exe, err, out)
+ id, err = buildid.ReadFile(exe)
+ if err != nil {
+ return "", err
}
- id = b.fileHash(exe)
+
+ // If we can't find a build ID, use a hash.
+ if id == "" {
+ id = b.fileHash(exe)
+ }
}
b.id.Lock()
- b.toolIDCache[name] = id
+ b.toolIDCache[key] = id
b.id.Unlock()
return id, nil
