cmd/compile/internal/types2: slice-to-array-pointer conversion requires go1.17
Add missing version check. Even though this is a new types2 error
we separate between the compiler and the types2 error message: we
have the compiler error message to match the compiler style, and
we have a types2-specific error message to match the types2 style
for these kinds of errors (for now).
Eventually we need to decide which style we like better and clean
this up.
Follow-up on https://golang.org/cl/301650.
Updates #395.
Change-Id: I5b779f345994c66b1f4a4db466466f98b7d3c491
Reviewed-on: https://go-review.googlesource.com/c/go/+/315169
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
diff --git a/src/cmd/compile/internal/types2/conversions.go b/src/cmd/compile/internal/types2/conversions.go
index 51be50e..30201e2 100644
--- a/src/cmd/compile/internal/types2/conversions.go
+++ b/src/cmd/compile/internal/types2/conversions.go
@@ -38,8 +38,10 @@
}
if !ok {
- check.errorf(x, "cannot convert %s to %s", x, T)
- x.mode = invalid
+ if x.mode != invalid {
+ check.errorf(x, "cannot convert %s to %s", x, T)
+ x.mode = invalid
+ }
return
}
@@ -141,7 +143,16 @@
if p := asPointer(T); p != nil {
if a := asArray(p.Elem()); a != nil {
if check.identical(s.Elem(), a.Elem()) {
- return true
+ if check == nil || check.allowVersion(check.pkg, 1, 17) {
+ return true
+ }
+ // check != nil
+ if check.conf.CompilerErrorMessages {
+ check.error(x, "conversion of slices to array pointers only supported as of -lang=go1.17")
+ } else {
+ check.error(x, "conversion of slices to array pointers requires go1.17 or later")
+ }
+ x.mode = invalid // avoid follow-up error
}
}
}
diff --git a/src/cmd/compile/internal/types2/decl.go b/src/cmd/compile/internal/types2/decl.go
index 4966f19..1333e4c 100644
--- a/src/cmd/compile/internal/types2/decl.go
+++ b/src/cmd/compile/internal/types2/decl.go
@@ -601,7 +601,7 @@
if alias {
// type alias declaration
- if !check.allowVersion(obj.pkg, 1, 9) {
+ if !check.allowVersion(check.pkg, 1, 9) {
if check.conf.CompilerErrorMessages {
check.error(tdecl, "type aliases only supported as of -lang=go1.9")
} else {
diff --git a/src/cmd/compile/internal/types2/testdata/check/go1_16.src b/src/cmd/compile/internal/types2/testdata/check/go1_16.src
new file mode 100644
index 0000000..fdf5c99
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/check/go1_16.src
@@ -0,0 +1,13 @@
+// Copyright 2021 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.
+
+// Check Go language version-specific errors.
+
+package go1_16 // go1.16
+
+type Slice []byte
+type Array [8]byte
+
+var s Slice
+var p = (*Array)(s /* ERROR requires go1.17 or later */ )
