go/types: correct result type for append (bug fix)
Rewrote existing code to prevent similar mistakes.
R=adonovan
CC=golang-dev
https://golang.org/cl/7129046
diff --git a/src/pkg/go/types/builtins.go b/src/pkg/go/types/builtins.go
index aabb2e66..3875a3c 100644
--- a/src/pkg/go/types/builtins.go
+++ b/src/pkg/go/types/builtins.go
@@ -21,8 +21,7 @@
id := bin.id
// declare before goto's
- var arg0 ast.Expr
- var typ0 Type
+ var arg0 ast.Expr // first argument, if present
// check argument count
n := len(args)
@@ -42,31 +41,24 @@
if n > 0 {
arg0 = args[0]
switch id {
- case _Make, _New:
- // argument must be a type
- typ0 = check.typ(arg0, false)
- if typ0 == Typ[Invalid] {
- goto Error
- }
- case _Trace:
- // _Trace implementation does the work
+ case _Make, _New, _Trace:
+ // respective cases below do the work
default:
// argument must be an expression
check.expr(x, arg0, nil, iota)
if x.mode == invalid {
goto Error
}
- typ0 = underlying(x.typ)
}
}
switch id {
case _Append:
- s, ok := typ0.(*Slice)
- if !ok {
+ if _, ok := underlying(x.typ).(*Slice); !ok {
check.invalidArg(x.pos(), "%s is not a typed slice", x)
goto Error
}
+ resultTyp := x.typ
for _, arg := range args[1:] {
check.expr(x, arg, nil, iota)
if x.mode == invalid {
@@ -75,12 +67,12 @@
// TODO(gri) check assignability
}
x.mode = value
- x.typ = s
+ x.typ = resultTyp
case _Cap, _Len:
mode := invalid
var val interface{}
- switch typ := implicitDeref(typ0).(type) {
+ switch typ := implicitDeref(underlying(x.typ)).(type) {
case *Basic:
if isString(typ) && id == _Len {
if x.mode == constant {
@@ -116,7 +108,7 @@
x.val = val
case _Close:
- ch, ok := typ0.(*Chan)
+ ch, ok := underlying(x.typ).(*Chan)
if !ok {
check.invalidArg(x.pos(), "%s is not a channel", x)
goto Error
@@ -182,7 +174,7 @@
}
var dst, src Type
- if t, ok := typ0.(*Slice); ok {
+ if t, ok := underlying(x.typ).(*Slice); ok {
dst = t.Elt
}
switch t := underlying(y.typ).(type) {
@@ -208,7 +200,7 @@
x.typ = Typ[Int]
case _Delete:
- m, ok := typ0.(*Map)
+ m, ok := underlying(x.typ).(*Map)
if !ok {
check.invalidArg(x.pos(), "%s is not a map", x)
goto Error
@@ -224,7 +216,7 @@
x.mode = novalue
case _Imag, _Real:
- if !isComplex(typ0) {
+ if !isComplex(x.typ) {
check.invalidArg(x.pos(), "%s must be a complex number", x)
goto Error
}
@@ -242,7 +234,7 @@
x.mode = value
}
k := Invalid
- switch typ0.(*Basic).Kind {
+ switch underlying(x.typ).(*Basic).Kind {
case Complex64:
k = Float32
case Complex128:
@@ -255,8 +247,12 @@
x.typ = Typ[k]
case _Make:
+ resultTyp := check.typ(arg0, false)
+ if resultTyp == Typ[Invalid] {
+ goto Error
+ }
var min int // minimum number of arguments
- switch underlying(typ0).(type) {
+ switch underlying(resultTyp).(type) {
case *Slice:
min = 2
case *Map, *Chan:
@@ -291,11 +287,15 @@
// safe to continue
}
x.mode = variable
- x.typ = typ0
+ x.typ = resultTyp
case _New:
+ resultTyp := check.typ(arg0, false)
+ if resultTyp == Typ[Invalid] {
+ goto Error
+ }
x.mode = variable
- x.typ = &Pointer{Base: typ0}
+ x.typ = &Pointer{Base: resultTyp}
case _Panic, _Print, _Println:
for _, arg := range args[1:] {
@@ -329,14 +329,14 @@
case _Sizeof:
x.mode = constant
+ x.val = sizeof(check.ctxt, x.typ)
x.typ = Typ[Uintptr]
- x.val = sizeof(check.ctxt, typ0)
case _Assert:
// assert(pred) causes a typechecker error if pred is false.
// The result of assert is the value of pred if there is no error.
// Note: assert is only available in self-test mode.
- if x.mode != constant || !isBoolean(typ0) {
+ if x.mode != constant || !isBoolean(x.typ) {
check.invalidArg(x.pos(), "%s is not a boolean constant", x)
goto Error
}
