gc: new typechecking rules

* Code for assignment, conversions now mirrors spec.
* Changed some snprint -> smprint.
* Renamed runtime functions to separate
  interface conversions from type assertions:
  convT2I, assertI2T, etc.
* Correct checking of \U sequences.

Fixes issue 840.
Fixes issue 830.
Fixes issue 778.

R=ken2
CC=golang-dev
http://codereview.appspot.com/1303042

1 files changed, 40 insertions, 31 deletions

diff --git a/test/interface/receiver1.go b/test/interface/receiver1.go
index 8ce96424e..51312d000 100644
--- a/test/interface/receiver1.go
+++ b/test/interface/receiver1.go
@@ -9,41 +9,50 @@
 package main
 
 type T int
+
 func (t T) V()
 func (t *T) P()
 
-type V interface { V() }
-type P interface { P(); V() }
+type V interface {
+	V()
+}
+type P interface {
+	P()
+	V()
+}
 
-type S struct { T; }
-type SP struct { *T; }
+type S struct {
+	T
+}
+type SP struct {
+	*T
+}
 
 func main() {
-	var t T;
-	var v V;
-	var p P;
-	var s S;
-	var sp SP;
-
-	v = t;
-	p = t;	// ERROR "is not|requires a pointer"
-	_, _= v, p;
-	v = &t;
-	p = &t;
-	_, _= v, p;
-
-	v = s;
-	p = s;	// ERROR "is not|requires a pointer"
-	_, _= v, p;
-	v = &s;
-	p = &s;
-	_, _= v, p;
-
-	v = sp;
-	p = sp;	// no error!
-	_, _= v, p;
-	v = &sp;
-	p = &sp;
-	_, _= v, p;
+	var t T
+	var v V
+	var p P
+	var s S
+	var sp SP
+
+	v = t
+	p = t // ERROR "does not implement|requires a pointer"
+	_, _ = v, p
+	v = &t
+	p = &t
+	_, _ = v, p
+
+	v = s
+	p = s // ERROR "does not implement|requires a pointer"
+	_, _ = v, p
+	v = &s
+	p = &s
+	_, _ = v, p
+
+	v = sp
+	p = sp // no error!
+	_, _ = v, p
+	v = &sp
+	p = &sp
+	_, _ = v, p
 }
-