gc: fix send precedence

Test and fix case found by Robert.
Add receive inside send to tree too.

R=ken2
CC=golang-dev
https://golang.org/cl/3973052

diff --git a/src/cmd/gc/go.y b/src/cmd/gc/go.y
index 1060fdd2bf22b061cf9a9fba6e59d216b5473531..b711d360d2d8813f19ed601d4e17834fa9f11405 100644 (file)
--- a/src/cmd/gc/go.y
+++ b/src/cmd/gc/go.y
@@ -93,9 +93,10 @@ static void fixlbrace(int);
 %type  <type>  hidden_type_func
 %type  <type>  hidden_type_recv_chan hidden_type_non_recv_chan
 
+%left          LCOMM   /* outside the usual hierarchy; here for good error messages */
+
 %left          LOROR
 %left          LANDAND
-%left          LCOMM
 %left          LEQ LNE LLE LGE LLT LGT
 %left          '+' '-' '|' '^'
 %left          '*' '/' '%' '&' LLSH LRSH LANDNOT

diff --git a/test/chan/sendstmt.go b/test/chan/sendstmt.go
new file mode 100644 (file)
index 0000000..ee6f765
--- /dev/null
+++ b/test/chan/sendstmt.go
@@ -0,0 +1,37 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2011 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.
+
+// Test various parsing cases that are a little
+// different now that send is a statement, not a expression.
+
+package main
+
+func main() {
+       chanchan()
+       sendprec()
+}
+
+func chanchan() {
+       cc := make(chan chan int, 1)
+       c := make(chan int, 1)
+       cc <- c
+       select {
+       case <-cc <- 2:
+       default:
+               panic("nonblock")
+       }
+       if <-c != 2 {
+               panic("bad receive")
+       }
+}
+
+func sendprec() {
+       c := make(chan bool, 1)
+       c <- false || true      // not a syntax error: same as c <- (false || true)
+       if !<-c {
+               panic("sent false")
+       }
+}