cmd/compile: builtins may be in the unsafe package

Now that unsafe.Sizeof and friends can operate on generic parameters,
and evaluate to non-constants, we need to export/import them correctly.

Fixes #48094

Change-Id: If3ebf77255385cd5462e13fb7ced8b157ba3cf5b
Reviewed-on: https://go-review.googlesource.com/c/go/+/346469
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

diff --git a/src/cmd/compile/internal/typecheck/iexport.go b/src/cmd/compile/internal/typecheck/iexport.go
index 89eab4df1625c1d40fc71f90ecae10810c6e1abe..f001017a867b273b21564e509e88abf710847053 100644 (file)
--- a/src/cmd/compile/internal/typecheck/iexport.go
+++ b/src/cmd/compile/internal/typecheck/iexport.go
@@ -1692,6 +1692,7 @@ func (w *exportWriter) expr(n ir.Node) {
                isBuiltin := n.BuiltinOp != ir.OXXX
                w.bool(isBuiltin)
                if isBuiltin {
+                       w.bool(n.Sym().Pkg == types.UnsafePkg)
                        w.string(n.Sym().Name)
                        break
                }

diff --git a/src/cmd/compile/internal/typecheck/iimport.go b/src/cmd/compile/internal/typecheck/iimport.go
index 0dfc33db201e96dd5e03ece02f5092de9006c727..45bf2563aa603c2018f611a2090f3deaa712cb80 100644 (file)
--- a/src/cmd/compile/internal/typecheck/iimport.go
+++ b/src/cmd/compile/internal/typecheck/iimport.go
@@ -1269,7 +1269,11 @@ func (r *importReader) node() ir.Node {
        case ir.ONAME:
                isBuiltin := r.bool()
                if isBuiltin {
-                       return types.BuiltinPkg.Lookup(r.string()).Def.(*ir.Name)
+                       pkg := types.BuiltinPkg
+                       if r.bool() {
+                               pkg = types.UnsafePkg
+                       }
+                       return pkg.Lookup(r.string()).Def.(*ir.Name)
                }
                return r.localName()
 

diff --git a/test/typeparam/issue48094.dir/a.go b/test/typeparam/issue48094.dir/a.go
new file mode 100644 (file)
index 0000000..dd8c16f
--- /dev/null
+++ b/test/typeparam/issue48094.dir/a.go
@@ -0,0 +1,26 @@
+// 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.
+
+package a
+
+import "unsafe"
+
+func F[T any]() uintptr {
+       var t T
+       return unsafe.Sizeof(t)
+}
+
+func G[T any]() uintptr {
+       var t T
+       return unsafe.Alignof(t)
+}
+
+//func H[T any]() uintptr {
+//     type S struct {
+//             a T
+//             b T
+//     }
+//     var s S
+//     return unsafe.Offsetof(s.b)
+//}

diff --git a/test/typeparam/issue48094.dir/main.go b/test/typeparam/issue48094.dir/main.go
new file mode 100644 (file)
index 0000000..eb1ddbe
--- /dev/null
+++ b/test/typeparam/issue48094.dir/main.go
@@ -0,0 +1,20 @@
+// 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.
+
+package main
+
+import "a"
+
+func main() {
+       if a.F[int64]() != 8 {
+               panic("bad")
+       }
+       if a.G[int8]() != 1 {
+               panic("bad")
+       }
+       // TODO: enable once 47631 is fixed.
+       //if a.H[int64]() != 8 {
+       //      panic("bad")
+       //}
+}

diff --git a/test/typeparam/issue48094.go b/test/typeparam/issue48094.go
new file mode 100644 (file)
index 0000000..76930e5
--- /dev/null
+++ b/test/typeparam/issue48094.go
@@ -0,0 +1,7 @@
+// rundir -G=3
+
+// 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.
+
+package ignored