gopls/internal/golang: package move: handle mixed build configs

When there are files in a metadata.Package that are ignored because
they are not in the package with the current build configuration,
we should not allow moving that package.

Change-Id: I2cc4f078113ce370cdafaee2333ffabc0befd673
Reviewed-on: https://go-review.googlesource.com/c/tools/+/721040
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

Author: madelinekalil

gopls/internal/golang/rename.go

@@ -452,7 +452,7 @@ func Rename(ctx context.Context, snapshot *cache.Snapshot, f file.Handle, pp pro
 
 	var (
 		editMap   map[protocol.DocumentURI][]diff.Edit
-		newPkgDir string // declared here so it can be used later to rename the package's enclosing directory
+		newPkgDir string // declared here so it can be used later to move the package's contents to the new directory
 	)
 	if inPackageName {
 		countRenamePackage.Inc()

gopls/internal/golang/rename_check.go

@@ -927,6 +927,14 @@ func checkPackageRename(opts *settings.Options, curPkg *cache.Package, f file.Ha
 	if newName == curPkg.String() || newName == string(curPkg.Metadata().Name) {
 		return f.URI().DirPath(), curPkg.Metadata().Name, curPkg.Metadata().PkgPath, nil
 	}
+
+	// If there are any Go files in the package that are not in the compiled package
+	// with the current build config, we should not allow a package move.
+	ignored := hasIgnoredGoFiles(curPkg)
+	if ignored {
+		return "", "", "", fmt.Errorf("moving a package with ignored files is not supported")
+	}
+
 	// TODO(mkalil): support relative paths
 	if build.IsLocalImport(newName) {
 		return "", "", "", fmt.Errorf("specifying relative paths in package rename not yet supported")
@@ -981,6 +989,18 @@ func checkPackageRename(opts *settings.Options, curPkg *cache.Package, f file.Ha
 	return newPkgDir, newPkgName, PackagePath(newName), nil
 }
 
+// hasIgnoredGoFiles returns true if the input pkg contains any Go files that
+// are not part of package pkg with the current build configuration.
+func hasIgnoredGoFiles(pkg *cache.Package) bool {
+	// If any ignored files are Go files, don't allow a package move.
+	for _, f := range pkg.Metadata().IgnoredFiles {
+		if strings.HasSuffix(f.Path(), ".go") {
+			return true
+		}
+	}
+	return false
+}
+
 // isLocal reports whether obj is local to some function.
 // Precondition: not a struct field or interface method.
 func isLocal(obj types.Object) bool {

gopls/internal/test/marker/testdata/rename/packagedecl.txt

@@ -102,6 +102,13 @@ import "golang.org/lsptests/rename/nine/nine/nine"
 -- othermoddir/go.mod --
 module mod.com/other
 
+-- foo/windows.go --
+//go:build windows
+package foo
+
+-- foo/default.go --
+//go:build !windows
+package foo //@ renameerr("foo", "golang.org/lsptests/rename/foo2", re"ignored files")
 
 -- @moveDownTwoDirs/nine/nine/nine/eight/eight.go --
 @@ -0,0 +1 @@