diff --git a/bp2build/compatibility.go b/bp2build/compatibility.go
new file mode 100644
index 0000000..5baa524
--- /dev/null
+++ b/bp2build/compatibility.go
@@ -0,0 +1,31 @@
+package bp2build
+
+import (
+	"android/soong/bazel"
+	"fmt"
+)
+
+// Data from the code generation process that is used to improve compatibility
+// between build systems.
+type CodegenCompatLayer struct {
+	// A map from the original module name to the generated/handcrafted Bazel
+	// label for legacy build systems to be able to build a fully-qualified
+	// Bazel target from an unique module name.
+	NameToLabelMap map[string]string
+}
+
+// Log an entry of module name -> Bazel target label.
+func (compatLayer CodegenCompatLayer) AddNameToLabelEntry(name, label string) {
+	// The module name may be prefixed with bazel.BazelTargetModuleNamePrefix if
+	// generated from bp2build.
+	name = bazel.StripNamePrefix(name)
+	if existingLabel, ok := compatLayer.NameToLabelMap[name]; ok {
+		panic(fmt.Errorf(
+			"Module '%s' maps to more than one Bazel target label: %s, %s. "+
+				"This shouldn't happen. It probably indicates a bug with the bp2build internals.",
+			name,
+			existingLabel,
+			label))
+	}
+	compatLayer.NameToLabelMap[name] = label
+}