[release-branch.go1.15] cmd/cgo: remove unnecessary space in cgo export header

The cgo header has an unnecessary space in the exported function
definition on non-windows goos.

This was introduced in go1.16 so it would be good to fix it before
release.

Example:

// Current behavior, notice there is an unecessary space
// between extern and void
extern  void Foo();

// With this CL
extern void Foo();

Updates #43591.

Change-Id: Ic2c21f8d806fe35a7be7183dbfe35ac605b6e4f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/283892
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Katie Hockman <katie@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/300694
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
index ee1c56349558345c8bb4f3ec2501d90413043ff2..be4f6ad2d5835ea27cfd5683df0ca8e592a39004 100644 (file)
--- a/src/cmd/cgo/out.go
+++ b/src/cmd/cgo/out.go
@@ -963,9 +963,9 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) {
                // Build the wrapper function compiled by gcc.
                gccExport := ""
                if goos == "windows" {
-                       gccExport = "__declspec(dllexport)"
+                       gccExport = "__declspec(dllexport) "
                }
-               s := fmt.Sprintf("%s %s %s(", gccExport, gccResult, exp.ExpName)
+               s := fmt.Sprintf("%s%s %s(", gccExport, gccResult, exp.ExpName)
                if fn.Recv != nil {
                        s += p.cgoType(fn.Recv.List[0].Type).C.String()
                        s += " recv"