cmd/go: do not permit importing a main package
Fixes #4210.
Change-Id: Id981814a6e55a57403ce7a8ac45ab3ba081a3a86
Reviewed-on: https://go-review.googlesource.com/10925
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index 4360603..0ba72b0 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -1830,3 +1830,21 @@
tg.cd(tg.path("src/rsc.io"))
tg.run("get", "./toolstash")
}
+
+// Test that you can not import a main package.
+func TestIssue4210(t *testing.T) {
+ tg := testgo(t)
+ defer tg.cleanup()
+ tg.tempFile("src/x/main.go", `package main
+ var X int
+ func main() {}`)
+ tg.tempFile("src/y/main.go", `package main
+ import "fmt"
+ import xmain "x"
+ func main() {
+ fmt.Println(xmain.X)
+ }`)
+ tg.setenv("GOPATH", tg.path("."))
+ tg.runFail("build", "y")
+ tg.grepBoth("is a program", `did not find expected error message ("is a program")`)
+}
diff --git a/src/cmd/go/pkg.go b/src/cmd/go/pkg.go
index cf3e8b3..71d6587 100644
--- a/src/cmd/go/pkg.go
+++ b/src/cmd/go/pkg.go
@@ -631,6 +631,16 @@
continue
}
p1 := loadImport(path, p.Dir, stk, p.build.ImportPos[path])
+ if p1.Name == "main" {
+ p.Error = &PackageError{
+ ImportStack: stk.copy(),
+ Err: fmt.Sprintf("import %q is a program, not an importable package", path),
+ }
+ pos := p.build.ImportPos[path]
+ if len(pos) > 0 {
+ p.Error.Pos = pos[0].String()
+ }
+ }
if p1.local {
if !p.local && p.Error == nil {
p.Error = &PackageError{
