From 57fa1c7c949c5ea1efd756e2ed0c4442998690a9 Mon Sep 17 00:00:00 2001 From: Anthony Sottile Date: Sat, 9 Sep 2017 21:38:51 -0700 Subject: [PATCH] cmd/cgo: treat simple C typedefs as go aliases Fixes #21809 Change-Id: Ic43077c6bea3c7cdc9611e74abf07b6deab70433 Reviewed-on: https://go-review.googlesource.com/62670 Run-TryBot: Ian Lance Taylor TryBot-Result: Gobot Gobot Reviewed-by: Ian Lance Taylor --- misc/cgo/test/cgo_test.go | 1 + misc/cgo/test/issue21809.go | 45 +++++++++++++++++++++++++++++++++++++ src/cmd/cgo/out.go | 8 ++++++- 3 files changed, 53 insertions(+), 1 deletion(-) create mode 100644 misc/cgo/test/issue21809.go diff --git a/misc/cgo/test/cgo_test.go b/misc/cgo/test/cgo_test.go index f6cf86befc..4d1bc378dc 100644 --- a/misc/cgo/test/cgo_test.go +++ b/misc/cgo/test/cgo_test.go @@ -82,5 +82,6 @@ func Test20266(t *testing.T) { test20266(t) } func Test20129(t *testing.T) { test20129(t) } func Test20910(t *testing.T) { test20910(t) } func Test21708(t *testing.T) { test21708(t) } +func Test21809(t *testing.T) { test21809(t) } func BenchmarkCgoCall(b *testing.B) { benchCgoCall(b) } diff --git a/misc/cgo/test/issue21809.go b/misc/cgo/test/issue21809.go new file mode 100644 index 0000000000..fd01dd71c3 --- /dev/null +++ b/misc/cgo/test/issue21809.go @@ -0,0 +1,45 @@ +// Copyright 2017 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 cgotest + +// Issue 21809. Compile C `typedef` to go type aliases. + +// typedef long MySigned_t; +// /* tests alias-to-alias */ +// typedef MySigned_t MySigned2_t; +// +// long takes_long(long x) { return x * x; } +// MySigned_t takes_typedef(MySigned_t x) { return x * x; } +import "C" + +import "testing" + +func test21809(t *testing.T) { + longVar := C.long(3) + typedefVar := C.MySigned_t(4) + typedefTypedefVar := C.MySigned2_t(5) + + // all three should be considered identical to `long` + if ret := C.takes_long(longVar); ret != 9 { + t.Errorf("got %v but expected %v", ret, 9) + } + if ret := C.takes_long(typedefVar); ret != 16 { + t.Errorf("got %v but expected %v", ret, 16) + } + if ret := C.takes_long(typedefTypedefVar); ret != 25 { + t.Errorf("got %v but expected %v", ret, 25) + } + + // They should also be identical to the typedef'd type + if ret := C.takes_typedef(longVar); ret != 9 { + t.Errorf("got %v but expected %v", ret, 9) + } + if ret := C.takes_typedef(typedefVar); ret != 16 { + t.Errorf("got %v but expected %v", ret, 16) + } + if ret := C.takes_typedef(typedefTypedefVar); ret != 25 { + t.Errorf("got %v but expected %v", ret, 25) + } +} diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go index edbfc35b1d..6df400d96c 100644 --- a/src/cmd/cgo/out.go +++ b/src/cmd/cgo/out.go @@ -110,7 +110,13 @@ func (p *Package) writeDefs() { // Which is not useful. Moreover we never override source info, // so subsequent source code uses the same source info. // Moreover, empty file name makes compile emit no source debug info at all. - noSourceConf.Fprint(fgo2, fset, def.Go) + var buf bytes.Buffer + noSourceConf.Fprint(&buf, fset, def.Go) + if bytes.HasPrefix(buf.Bytes(), []byte("_Ctype_")) { + // This typedef is of the form `typedef a b` and should be an alias. + fmt.Fprintf(fgo2, "= ") + } + fmt.Fprintf(fgo2, "%s", buf.Bytes()) fmt.Fprintf(fgo2, "\n\n") } if *gccgo { -- 2.50.0