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cmd/compile: disallow typed non-integer constant len and cap make arguments

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make(T, n, m) returns a slice of type T with length n and capacity m
where "The size arguments n and m must be of integer type or untyped."
https://tip.golang.org/ref/spec#Making_slices_maps_and_channels

The failure to reject typed non-integer size arguments in make
during compile time was uncovered after https://golang.org/cl/27851
changed the generation of makeslice calls.

Fixes   #16940
Updates #16949

Change-Id: Ib1e3576f0e6ad199c9b16b7a50c2db81290c63b4
Reviewed-on: https://go-review.googlesource.com/28301
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This commit is contained in:
Martin Möhrmann 2016-09-01 08:31:37 +02:00 committed by Martin Möhrmann
parent 809bb3a71c
commit 8895a99c9f
2 changed files with 35 additions and 5 deletions
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10
src/cmd/compile/internal/gc/typecheck.go
View file

@ -3754,6 +3754,11 @@ ret:
}
func checkmake(t *Type, arg string, n *Node) bool {
if !n.Type.IsInteger() && n.Type.Etype != TIDEAL {
Yyerror("non-integer %s argument in make(%v) - %v", arg, t, n.Type)
return false
}
if n.Op == OLITERAL {
switch n.Val().Ctype() {
case CTINT, CTRUNE, CTFLT, CTCPLX:
@ -3779,11 +3784,6 @@ func checkmake(t *Type, arg string, n *Node) bool {
}
}
if !n.Type.IsInteger() && n.Type.Etype != TIDEAL {
Yyerror("non-integer %s argument in make(%v) - %v", arg, t, n.Type)
return false
}
// Defaultlit still necessary for non-constant: n might be 1<<k.
n = defaultlit(n, Types[TINT])

30
test/fixedbugs/issue16949.go Normal file
View file

@ -0,0 +1,30 @@
// errorcheck
// Copyright 2016 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.
// Ensure that typed non-integer len and cap make arguments are not accepted.
package main
var sink []byte
func main() {
sink = make([]byte, 1.0)
sink = make([]byte, float32(1.0)) // ERROR "non-integer.*len"
sink = make([]byte, float64(1.0)) // ERROR "non-integer.*len"
sink = make([]byte, 0, 1.0)
sink = make([]byte, 0, float32(1.0)) // ERROR "non-integer.*cap"
sink = make([]byte, 0, float64(1.0)) // ERROR "non-integer.*cap"
sink = make([]byte, 1+0i)
sink = make([]byte, complex64(1+0i)) // ERROR "non-integer.*len"
sink = make([]byte, complex128(1+0i)) // ERROR "non-integer.*len"
sink = make([]byte, 0, 1+0i)
sink = make([]byte, 0, complex64(1+0i)) // ERROR "non-integer.*cap"
sink = make([]byte, 0, complex128(1+0i)) // ERROR "non-integer.*cap"
}