1 files changed, 125 insertions, 0 deletions
diff --git a/tools/aconfig/src/codegen/mod.rs b/tools/aconfig/src/codegen/mod.rs
new file mode 100644
index 0000000000..abc27c678f
--- /dev/null
+++ b/tools/aconfig/src/codegen/mod.rs
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+pub mod cpp;
+pub mod java;
+pub mod rust;
+
+use anyhow::{ensure, Result};
+
+pub fn is_valid_name_ident(s: &str) -> bool {
+    // Identifiers must match [a-z][a-z0-9_]*, except consecutive underscores are not allowed
+    if s.contains("__") {
+        return false;
+    }
+    let mut chars = s.chars();
+    let Some(first) = chars.next() else {
+        return false;
+    };
+    if !first.is_ascii_lowercase() {
+        return false;
+    }
+    chars.all(|ch| ch.is_ascii_lowercase() || ch.is_ascii_digit() || ch == '_')
+}
+
+pub fn is_valid_package_ident(s: &str) -> bool {
+    if !s.contains('.') {
+        return false;
+    }
+    s.split('.').all(is_valid_name_ident)
+}
+
+pub fn is_valid_container_ident(s: &str) -> bool {
+    is_valid_name_ident(s) || s.split('.').all(is_valid_name_ident)
+}
+
+pub fn create_device_config_ident(package: &str, flag_name: &str) -> Result<String> {
+    ensure!(is_valid_package_ident(package), "bad package");
+    ensure!(is_valid_name_ident(flag_name), "bad flag name");
+    Ok(format!("{}.{}", package, flag_name))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_is_valid_name_ident() {
+        assert!(is_valid_name_ident("foo"));
+        assert!(is_valid_name_ident("foo_bar_123"));
+        assert!(is_valid_name_ident("foo_"));
+
+        assert!(!is_valid_name_ident(""));
+        assert!(!is_valid_name_ident("123_foo"));
+        assert!(!is_valid_name_ident("foo-bar"));
+        assert!(!is_valid_name_ident("foo-b\u{00e5}r"));
+        assert!(!is_valid_name_ident("foo__bar"));
+        assert!(!is_valid_name_ident("_foo"));
+    }
+
+    #[test]
+    fn test_is_valid_package_ident() {
+        assert!(is_valid_package_ident("foo.bar"));
+        assert!(is_valid_package_ident("foo.bar_baz"));
+        assert!(is_valid_package_ident("foo.bar.a123"));
+
+        assert!(!is_valid_package_ident("foo_bar_123"));
+        assert!(!is_valid_package_ident("foo"));
+        assert!(!is_valid_package_ident("foo._bar"));
+        assert!(!is_valid_package_ident(""));
+        assert!(!is_valid_package_ident("123_foo"));
+        assert!(!is_valid_package_ident("foo-bar"));
+        assert!(!is_valid_package_ident("foo-b\u{00e5}r"));
+        assert!(!is_valid_package_ident("foo.bar.123"));
+        assert!(!is_valid_package_ident(".foo.bar"));
+        assert!(!is_valid_package_ident("foo.bar."));
+        assert!(!is_valid_package_ident("."));
+        assert!(!is_valid_package_ident(".."));
+        assert!(!is_valid_package_ident("foo..bar"));
+        assert!(!is_valid_package_ident("foo.__bar"));
+    }
+
+    #[test]
+    fn test_is_valid_container_ident() {
+        assert!(is_valid_container_ident("foo.bar"));
+        assert!(is_valid_container_ident("foo.bar_baz"));
+        assert!(is_valid_container_ident("foo.bar.a123"));
+        assert!(is_valid_container_ident("foo"));
+        assert!(is_valid_container_ident("foo_bar_123"));
+
+        assert!(!is_valid_container_ident(""));
+        assert!(!is_valid_container_ident("foo._bar"));
+        assert!(!is_valid_container_ident("_foo"));
+        assert!(!is_valid_container_ident("123_foo"));
+        assert!(!is_valid_container_ident("foo-bar"));
+        assert!(!is_valid_container_ident("foo-b\u{00e5}r"));
+        assert!(!is_valid_container_ident("foo.bar.123"));
+        assert!(!is_valid_container_ident(".foo.bar"));
+        assert!(!is_valid_container_ident("foo.bar."));
+        assert!(!is_valid_container_ident("."));
+        assert!(!is_valid_container_ident(".."));
+        assert!(!is_valid_container_ident("foo..bar"));
+        assert!(!is_valid_container_ident("foo.__bar"));
+    }
+
+    #[test]
+    fn test_create_device_config_ident() {
+        assert_eq!(
+            "com.foo.bar.some_flag",
+            create_device_config_ident("com.foo.bar", "some_flag").unwrap()
+        );
+    }
+}