runtime: use go generate for zcallback_windows.go

replacement for CL 180640043

Change-Id: I8ff36645cfcbbda338faf7b29cbfdb95c47d5ec4
Reviewed-on: https://go-review.googlesource.com/1765
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

1 files changed, 22 insertions, 1 deletions

diff --git a/src/runtime/wincallback.go b/src/runtime/wincallback.go
index 4c0daf17c0..a16ad21cd5 100644
--- a/src/runtime/wincallback.go
+++ b/src/runtime/wincallback.go
@@ -17,7 +17,7 @@ import (
 
 const maxCallback = 2000
 
-func main() {
+func genasm() {
 	var buf bytes.Buffer
 
 	buf.WriteString(`// generated by wincallback.go; run go generate
@@ -41,3 +41,24 @@ TEXT runtime·callbackasm(SB),7,$0
 		os.Exit(2)
 	}
 }
+
+func gengo() {
+	var buf bytes.Buffer
+
+	buf.WriteString(fmt.Sprintf(`// generated by wincallback.go; run go generate
+
+package runtime
+
+const cb_max = %d // maximum number of windows callbacks allowed
+`, maxCallback))
+	err := ioutil.WriteFile("zcallback_windows.go", buf.Bytes(), 0666)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "wincallback: %s\n", err)
+		os.Exit(2)
+	}
+}
+
+func main() {
+	genasm()
+	gengo()
+}