updated godoc documentation

R=r
http://go/go-review/1026007

diff --git a/src/cmd/godoc/doc.go b/src/cmd/godoc/doc.go
index cdf107ab292cbd8933a867a742d331c886774ede..a116e321fb7ee4ed744a554546f9a8d68fad3a87 100644 (file)
--- a/src/cmd/godoc/doc.go
+++ b/src/cmd/godoc/doc.go
@@ -25,11 +25,13 @@ The flags are:
                verbose mode
        -tabwidth=4
                width of tabs in units of spaces
+       -cmdroot="src/cmd"
+               root command source directory (if unrooted, relative to -goroot)
        -tmplroot="lib/godoc"
-               root template directory (if unrooted, relative to --goroot)
+               root template directory (if unrooted, relative to -goroot)
        -pkgroot="src/pkg"
-               root package source directory (if unrooted, relative to --goroot)
-       -html=
+               root package source directory (if unrooted, relative to -goroot)
+       -html
                print HTML in command-line mode
        -goroot=$GOROOT
                Go root directory
@@ -42,5 +44,17 @@ The flags are:
        -sync_minutes=0
                sync interval in minutes; sync is disabled if <= 0
 
+When godoc runs as a web server, it creates a search index from all .go files
+under $GOROOT (excluding files starting with .). The index is created at startup
+and is automatically updated every time the -sync command terminates with exit
+status 0, indicating that files have changed.
+
+If the sync exit status is 1, godoc assumes that it succeeded without errors
+but that no files changed; the index is not updated in this case.
+
+In all other cases, sync is assumed to have failed and godoc backs off running
+sync exponentially (up to 1 day). As soon as sync succeeds again (exit status 0
+or 1), the normal sync rhythm is re-established.
+
 */
 package documentation