aconfig: allow dots in package fields

Allow package fields to include dots.

Update the generated code based on the package name: if the package name
is com.android.example:

  - java: package com.android.example; ...
  - C++: namespace com::android::example { ... }
  - Rust: mod com { mod android { mod example { ... } } }

Also, update examples to use dots in the package fields.

Also, remove unnecessary #include from the auto-generated C++ code: the
header should not include itself.

Bug: 285000854
Test: atest aconfig.test
Change-Id: I8a5352e25c64c34dee0725202a1b7c9957819de8
diff --git a/tools/aconfig/src/codegen_rust.rs b/tools/aconfig/src/codegen_rust.rs
index e972185..e27aa9c 100644
--- a/tools/aconfig/src/codegen_rust.rs
+++ b/tools/aconfig/src/codegen_rust.rs
@@ -24,9 +24,12 @@
 
 pub fn generate_rust_code(cache: &Cache) -> Result<OutputFile> {
     let package = cache.package();
-    let parsed_flags: Vec<TemplateParsedFlag> =
-        cache.iter().map(|item| create_template_parsed_flag(package, item)).collect();
-    let context = TemplateContext { package: package.to_string(), parsed_flags };
+    let parsed_flags: Vec<TemplateParsedFlag> = cache.iter().map(|item| item.into()).collect();
+    let context = TemplateContext {
+        package: package.to_string(),
+        parsed_flags,
+        modules: package.split('.').map(|s| s.to_string()).collect::<Vec<_>>(),
+    };
     let mut template = TinyTemplate::new();
     template.add_template("rust_code_gen", include_str!("../templates/rust.template"))?;
     let contents = template.render("rust_code_gen", &context)?;
@@ -38,12 +41,12 @@
 struct TemplateContext {
     pub package: String,
     pub parsed_flags: Vec<TemplateParsedFlag>,
+    pub modules: Vec<String>,
 }
 
 #[derive(Serialize)]
 struct TemplateParsedFlag {
     pub name: String,
-    pub fn_name: String,
 
     // TinyTemplate's conditionals are limited to single <bool> expressions; list all options here
     // Invariant: exactly one of these fields will be true
@@ -52,28 +55,29 @@
     pub is_read_write: bool,
 }
 
-#[allow(clippy::nonminimal_bool)]
-fn create_template_parsed_flag(package: &str, item: &Item) -> TemplateParsedFlag {
-    let template = TemplateParsedFlag {
-        name: item.name.clone(),
-        fn_name: format!("{}_{}", package, &item.name),
-        is_read_only_enabled: item.permission == Permission::ReadOnly
-            && item.state == FlagState::Enabled,
-        is_read_only_disabled: item.permission == Permission::ReadOnly
-            && item.state == FlagState::Disabled,
-        is_read_write: item.permission == Permission::ReadWrite,
-    };
-    #[rustfmt::skip]
-    debug_assert!(
-        (template.is_read_only_enabled && !template.is_read_only_disabled && !template.is_read_write) ||
-        (!template.is_read_only_enabled && template.is_read_only_disabled && !template.is_read_write) ||
-        (!template.is_read_only_enabled && !template.is_read_only_disabled && template.is_read_write),
-        "TemplateParsedFlag invariant failed: {} {} {}",
-        template.is_read_only_enabled,
-        template.is_read_only_disabled,
-        template.is_read_write,
-    );
-    template
+impl From<&Item> for TemplateParsedFlag {
+    #[allow(clippy::nonminimal_bool)]
+    fn from(item: &Item) -> Self {
+        let template = TemplateParsedFlag {
+            name: item.name.clone(),
+            is_read_only_enabled: item.permission == Permission::ReadOnly
+                && item.state == FlagState::Enabled,
+            is_read_only_disabled: item.permission == Permission::ReadOnly
+                && item.state == FlagState::Disabled,
+            is_read_write: item.permission == Permission::ReadWrite,
+        };
+        #[rustfmt::skip]
+        debug_assert!(
+            (template.is_read_only_enabled && !template.is_read_only_disabled && !template.is_read_write) ||
+            (!template.is_read_only_enabled && template.is_read_only_disabled && !template.is_read_write) ||
+            (!template.is_read_only_enabled && !template.is_read_only_disabled && template.is_read_write),
+            "TemplateParsedFlag invariant failed: {} {} {}",
+            template.is_read_only_enabled,
+            template.is_read_only_disabled,
+            template.is_read_write,
+        );
+        template
+    }
 }
 
 #[cfg(test)]
@@ -86,24 +90,33 @@
         let generated = generate_rust_code(&cache).unwrap();
         assert_eq!("src/lib.rs", format!("{}", generated.path.display()));
         let expected = r#"
+pub mod com {
+pub mod android {
+pub mod aconfig {
+pub mod test {
 #[inline(always)]
-pub const fn r#test_disabled_ro() -> bool {
+pub const fn r#disabled_ro() -> bool {
     false
 }
 
 #[inline(always)]
-pub fn r#test_disabled_rw() -> bool {
-    flags_rust::GetServerConfigurableFlag("test", "disabled_rw", "false") == "true"
+pub fn r#disabled_rw() -> bool {
+    flags_rust::GetServerConfigurableFlag("com.android.aconfig.test", "disabled_rw", "false") == "true"
 }
 
 #[inline(always)]
-pub const fn r#test_enabled_ro() -> bool {
+pub const fn r#enabled_ro() -> bool {
     true
 }
 
 #[inline(always)]
-pub fn r#test_enabled_rw() -> bool {
-    flags_rust::GetServerConfigurableFlag("test", "enabled_rw", "false") == "true"
+pub fn r#enabled_rw() -> bool {
+    flags_rust::GetServerConfigurableFlag("com.android.aconfig.test", "enabled_rw", "false") == "true"
+}
+
+}
+}
+}
 }
 "#;
         assert_eq!(expected.trim(), String::from_utf8(generated.contents).unwrap().trim());