cmd/go: permit C files if the package uses SWIG

They will be compiled and added to the archive, just as though the
package used cgo.  In effect all SWIG packages now use cgo anyhow.

Change-Id: I5d5a28ed0ec4295f24036b2834218bc980f080d0
Reviewed-on: https://go-review.googlesource.com/10146
Reviewed-by: Minux Ma <minux@golang.org>

diff --git a/src/cmd/go/pkg.go b/src/cmd/go/pkg.go
index 7a71471340f8fd52b8f86d8302580a88f14556ec..601c30362ff2592e65950dda5b5ae392f730c948 100644 (file)
--- a/src/cmd/go/pkg.go
+++ b/src/cmd/go/pkg.go
@@ -673,10 +673,10 @@ func (p *Package) load(stk *importStack, bp *build.Package, err error) *Package
        p.Target = p.target
 
        // The gc toolchain only permits C source files with cgo.
-       if len(p.CFiles) > 0 && !p.usesCgo() && buildContext.Compiler == "gc" {
+       if len(p.CFiles) > 0 && !p.usesCgo() && !p.usesSwig() && buildContext.Compiler == "gc" {
                p.Error = &PackageError{
                        ImportStack: stk.copy(),
-                       Err:         fmt.Sprintf("C source files not allowed when not using cgo: %s", strings.Join(p.CFiles, " ")),
+                       Err:         fmt.Sprintf("C source files not allowed when not using cgo or SWIG: %s", strings.Join(p.CFiles, " ")),
                }
                return p
        }