Import protobuf-2.14.0

* Add OWNERS and Android.bp
* add generated version.rs into out

Bug: 143953733
Test: make
Change-Id: Ib53a973b74679c4dd78e2de2fa54141e55048c17
diff --git a/src/descriptorx.rs b/src/descriptorx.rs
new file mode 100644
index 0000000..033aa2a
--- /dev/null
+++ b/src/descriptorx.rs
@@ -0,0 +1,657 @@
+// Should not be a part of public API
+#![doc(hidden)]
+
+use descriptor::DescriptorProto;
+use descriptor::EnumDescriptorProto;
+use descriptor::EnumValueDescriptorProto;
+use descriptor::FieldDescriptorProto;
+/// utilities to work with descriptor
+use descriptor::FileDescriptorProto;
+use descriptor::OneofDescriptorProto;
+
+use rust;
+use strx;
+
+// Copy-pasted from libsyntax.
+fn ident_start(c: char) -> bool {
+    (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_'
+}
+
+// Copy-pasted from libsyntax.
+fn ident_continue(c: char) -> bool {
+    (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_'
+}
+
+pub fn proto_path_to_rust_mod(path: &str) -> String {
+    let without_dir = strx::remove_to(path, '/');
+    let without_suffix = strx::remove_suffix(without_dir, ".proto");
+
+    let name = without_suffix
+        .chars()
+        .enumerate()
+        .map(|(i, c)| {
+            let valid = if i == 0 {
+                ident_start(c)
+            } else {
+                ident_continue(c)
+            };
+            if valid {
+                c
+            } else {
+                '_'
+            }
+        })
+        .collect::<String>();
+
+    let name = if rust::is_rust_keyword(&name) {
+        format!("{}_pb", name)
+    } else {
+        name
+    };
+    name
+}
+
+pub struct RootScope<'a> {
+    pub file_descriptors: &'a [FileDescriptorProto],
+}
+
+impl<'a> RootScope<'a> {
+    fn packages(&'a self) -> Vec<FileScope<'a>> {
+        self.file_descriptors
+            .iter()
+            .map(|fd| FileScope {
+                file_descriptor: fd,
+            })
+            .collect()
+    }
+
+    // find enum by fully qualified name
+    pub fn find_enum(&'a self, fqn: &str) -> EnumWithScope<'a> {
+        match self.find_message_or_enum(fqn) {
+            MessageOrEnumWithScope::Enum(e) => e,
+            _ => panic!("not an enum: {}", fqn),
+        }
+    }
+
+    // find message by fully qualified name
+    pub fn find_message(&'a self, fqn: &str) -> MessageWithScope<'a> {
+        match self.find_message_or_enum(fqn) {
+            MessageOrEnumWithScope::Message(m) => m,
+            _ => panic!("not a message: {}", fqn),
+        }
+    }
+
+    // find message or enum by fully qualified name
+    pub fn find_message_or_enum(&'a self, fqn: &str) -> MessageOrEnumWithScope<'a> {
+        assert!(fqn.starts_with("."), "name must start with dot: {}", fqn);
+        let fqn1 = &fqn[1..];
+        self.packages()
+            .into_iter()
+            .flat_map(|p| {
+                (if p.get_package().is_empty() {
+                    p.find_message_or_enum(fqn1)
+                } else if fqn1.starts_with(&(p.get_package().to_string() + ".")) {
+                    let remaining = &fqn1[(p.get_package().len() + 1)..];
+                    p.find_message_or_enum(remaining)
+                } else {
+                    None
+                })
+                .into_iter()
+            })
+            .next()
+            .expect(&format!("enum not found by name: {}", fqn))
+    }
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum Syntax {
+    PROTO2,
+    PROTO3,
+}
+
+impl Syntax {
+    pub fn parse(s: &str) -> Self {
+        match s {
+            "" | "proto2" => Syntax::PROTO2,
+            "proto3" => Syntax::PROTO3,
+            _ => panic!("unsupported syntax value: {:?}", s),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct FileScope<'a> {
+    pub file_descriptor: &'a FileDescriptorProto,
+}
+
+impl<'a> FileScope<'a> {
+    fn get_package(&self) -> &'a str {
+        self.file_descriptor.get_package()
+    }
+
+    pub fn syntax(&self) -> Syntax {
+        Syntax::parse(self.file_descriptor.get_syntax())
+    }
+
+    pub fn to_scope(&self) -> Scope<'a> {
+        Scope {
+            file_scope: self.clone(),
+            path: Vec::new(),
+        }
+    }
+
+    fn find_message_or_enum(&self, name: &str) -> Option<MessageOrEnumWithScope<'a>> {
+        assert!(!name.starts_with("."));
+        self.find_messages_and_enums()
+            .into_iter()
+            .filter(|e| e.name_to_package() == name)
+            .next()
+    }
+
+    // find all enums in given file descriptor
+    pub fn find_enums(&self) -> Vec<EnumWithScope<'a>> {
+        let mut r = Vec::new();
+
+        self.to_scope().walk_scopes(|scope| {
+            r.extend(scope.get_enums());
+        });
+
+        r
+    }
+
+    // find all messages in given file descriptor
+    pub fn find_messages(&self) -> Vec<MessageWithScope<'a>> {
+        let mut r = Vec::new();
+
+        self.to_scope().walk_scopes(|scope| {
+            r.extend(scope.get_messages());
+        });
+
+        r
+    }
+
+    // find all messages and enums in given file descriptor
+    pub fn find_messages_and_enums(&self) -> Vec<MessageOrEnumWithScope<'a>> {
+        let mut r = Vec::new();
+
+        self.to_scope().walk_scopes(|scope| {
+            r.extend(scope.get_messages_and_enums());
+        });
+
+        r
+    }
+}
+
+#[derive(Clone)]
+pub struct Scope<'a> {
+    pub file_scope: FileScope<'a>,
+    pub path: Vec<&'a DescriptorProto>,
+}
+
+impl<'a> Scope<'a> {
+    pub fn get_file_descriptor(&self) -> &'a FileDescriptorProto {
+        self.file_scope.file_descriptor
+    }
+
+    // get message descriptors in this scope
+    fn get_message_descriptors(&self) -> &'a [DescriptorProto] {
+        if self.path.is_empty() {
+            self.file_scope.file_descriptor.get_message_type()
+        } else {
+            self.path.last().unwrap().get_nested_type()
+        }
+    }
+
+    // get enum descriptors in this scope
+    fn get_enum_descriptors(&self) -> &'a [EnumDescriptorProto] {
+        if self.path.is_empty() {
+            self.file_scope.file_descriptor.get_enum_type()
+        } else {
+            self.path.last().unwrap().get_enum_type()
+        }
+    }
+
+    // get messages with attached scopes in this scope
+    pub fn get_messages(&self) -> Vec<MessageWithScope<'a>> {
+        self.get_message_descriptors()
+            .iter()
+            .map(|m| MessageWithScope {
+                scope: self.clone(),
+                message: m,
+            })
+            .collect()
+    }
+
+    // get enums with attached scopes in this scope
+    pub fn get_enums(&self) -> Vec<EnumWithScope<'a>> {
+        self.get_enum_descriptors()
+            .iter()
+            .map(|e| EnumWithScope {
+                scope: self.clone(),
+                en: e,
+            })
+            .collect()
+    }
+
+    // get messages and enums with attached scopes in this scope
+    pub fn get_messages_and_enums(&self) -> Vec<MessageOrEnumWithScope<'a>> {
+        self.get_messages()
+            .into_iter()
+            .map(|m| MessageOrEnumWithScope::Message(m))
+            .chain(
+                self.get_enums()
+                    .into_iter()
+                    .map(|m| MessageOrEnumWithScope::Enum(m)),
+            )
+            .collect()
+    }
+
+    // nested scopes, i. e. scopes of nested messages
+    fn nested_scopes(&self) -> Vec<Scope<'a>> {
+        self.get_message_descriptors()
+            .iter()
+            .map(|m| {
+                let mut nested = self.clone();
+                nested.path.push(m);
+                nested
+            })
+            .collect()
+    }
+
+    fn walk_scopes_impl<F: FnMut(&Scope<'a>)>(&self, callback: &mut F) {
+        (*callback)(self);
+
+        for nested in self.nested_scopes() {
+            nested.walk_scopes_impl(callback);
+        }
+    }
+
+    // apply callback for this scope and all nested scopes
+    fn walk_scopes<F>(&self, mut callback: F)
+    where
+        F: FnMut(&Scope<'a>),
+    {
+        self.walk_scopes_impl(&mut callback);
+    }
+
+    pub fn prefix(&self) -> String {
+        if self.path.is_empty() {
+            "".to_string()
+        } else {
+            let v: Vec<&'a str> = self.path.iter().map(|m| m.get_name()).collect();
+            let mut r = v.join(".");
+            r.push_str(".");
+            r
+        }
+    }
+
+    // rust type name prefix for this scope
+    pub fn rust_prefix(&self) -> String {
+        self.prefix().replace(".", "_")
+    }
+}
+
+pub trait WithScope<'a> {
+    fn get_scope(&self) -> &Scope<'a>;
+
+    fn get_file_descriptor(&self) -> &'a FileDescriptorProto {
+        self.get_scope().get_file_descriptor()
+    }
+
+    // message or enum name
+    fn get_name(&self) -> &'a str;
+
+    fn escape_prefix(&self) -> &'static str;
+
+    fn name_to_package(&self) -> String {
+        let mut r = self.get_scope().prefix();
+        r.push_str(self.get_name());
+        r
+    }
+
+    /// Return absolute name starting with dot
+    fn name_absolute(&self) -> String {
+        let mut r = String::new();
+        r.push_str(".");
+        let package = self.get_file_descriptor().get_package();
+        if !package.is_empty() {
+            r.push_str(package);
+            r.push_str(".");
+        }
+        r.push_str(&self.name_to_package());
+        r
+    }
+
+    // rust type name of this descriptor
+    fn rust_name(&self) -> String {
+        let mut r = self.get_scope().rust_prefix();
+        // Only escape if prefix is not empty
+        if r.is_empty() && rust::is_rust_keyword(self.get_name()) {
+            r.push_str(self.escape_prefix());
+        }
+        r.push_str(self.get_name());
+        r
+    }
+
+    // fully-qualified name of this type
+    fn rust_fq_name(&self) -> String {
+        format!(
+            "{}::{}",
+            proto_path_to_rust_mod(self.get_scope().get_file_descriptor().get_name()),
+            self.rust_name()
+        )
+    }
+}
+
+#[derive(Clone)]
+pub struct MessageWithScope<'a> {
+    pub scope: Scope<'a>,
+    pub message: &'a DescriptorProto,
+}
+
+impl<'a> WithScope<'a> for MessageWithScope<'a> {
+    fn get_scope(&self) -> &Scope<'a> {
+        &self.scope
+    }
+
+    fn escape_prefix(&self) -> &'static str {
+        "message_"
+    }
+
+    fn get_name(&self) -> &'a str {
+        self.message.get_name()
+    }
+}
+
+impl<'a> MessageWithScope<'a> {
+    pub fn into_scope(mut self) -> Scope<'a> {
+        self.scope.path.push(self.message);
+        self.scope
+    }
+
+    pub fn to_scope(&self) -> Scope<'a> {
+        self.clone().into_scope()
+    }
+
+    pub fn fields(&self) -> Vec<FieldWithContext<'a>> {
+        self.message
+            .get_field()
+            .iter()
+            .map(|f| FieldWithContext {
+                field: f,
+                message: self.clone(),
+            })
+            .collect()
+    }
+
+    pub fn oneofs(&self) -> Vec<OneofWithContext<'a>> {
+        self.message
+            .get_oneof_decl()
+            .iter()
+            .enumerate()
+            .map(|(index, oneof)| OneofWithContext {
+                message: self.clone(),
+                oneof: &oneof,
+                index: index as u32,
+            })
+            .collect()
+    }
+
+    pub fn oneof_by_index(&self, index: u32) -> OneofWithContext<'a> {
+        self.oneofs().swap_remove(index as usize)
+    }
+
+    /// Pair of (key, value) if this message is map entry
+    pub fn map_entry(&'a self) -> Option<(FieldWithContext<'a>, FieldWithContext<'a>)> {
+        if self.message.get_options().get_map_entry() {
+            let key = self
+                .fields()
+                .into_iter()
+                .find(|f| f.field.get_number() == 1)
+                .unwrap();
+            let value = self
+                .fields()
+                .into_iter()
+                .find(|f| f.field.get_number() == 2)
+                .unwrap();
+            Some((key, value))
+        } else {
+            None
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct EnumWithScope<'a> {
+    pub scope: Scope<'a>,
+    pub en: &'a EnumDescriptorProto,
+}
+
+impl<'a> EnumWithScope<'a> {
+    // enum values
+    pub fn values(&'a self) -> &'a [EnumValueDescriptorProto] {
+        self.en.get_value()
+    }
+
+    // find enum value by name
+    pub fn value_by_name(&'a self, name: &str) -> &'a EnumValueDescriptorProto {
+        self.en
+            .get_value()
+            .into_iter()
+            .find(|v| v.get_name() == name)
+            .unwrap()
+    }
+}
+
+pub trait EnumValueDescriptorEx {
+    fn rust_name(&self) -> String;
+}
+
+impl EnumValueDescriptorEx for EnumValueDescriptorProto {
+    fn rust_name(&self) -> String {
+        let mut r = String::new();
+        if rust::is_rust_keyword(self.get_name()) {
+            r.push_str("value_");
+        }
+        r.push_str(self.get_name());
+        r
+    }
+}
+
+impl<'a> WithScope<'a> for EnumWithScope<'a> {
+    fn get_scope(&self) -> &Scope<'a> {
+        &self.scope
+    }
+
+    fn escape_prefix(&self) -> &'static str {
+        "enum_"
+    }
+
+    fn get_name(&self) -> &'a str {
+        self.en.get_name()
+    }
+}
+
+pub enum MessageOrEnumWithScope<'a> {
+    Message(MessageWithScope<'a>),
+    Enum(EnumWithScope<'a>),
+}
+
+impl<'a> WithScope<'a> for MessageOrEnumWithScope<'a> {
+    fn get_scope(&self) -> &Scope<'a> {
+        match self {
+            &MessageOrEnumWithScope::Message(ref m) => m.get_scope(),
+            &MessageOrEnumWithScope::Enum(ref e) => e.get_scope(),
+        }
+    }
+
+    fn escape_prefix(&self) -> &'static str {
+        match self {
+            &MessageOrEnumWithScope::Message(ref m) => m.escape_prefix(),
+            &MessageOrEnumWithScope::Enum(ref e) => e.escape_prefix(),
+        }
+    }
+
+    fn get_name(&self) -> &'a str {
+        match self {
+            &MessageOrEnumWithScope::Message(ref m) => m.get_name(),
+            &MessageOrEnumWithScope::Enum(ref e) => e.get_name(),
+        }
+    }
+}
+
+pub trait FieldDescriptorProtoExt {
+    fn rust_name(&self) -> String;
+}
+
+impl FieldDescriptorProtoExt for FieldDescriptorProto {
+    fn rust_name(&self) -> String {
+        if rust::is_rust_keyword(self.get_name()) {
+            format!("field_{}", self.get_name())
+        } else {
+            self.get_name().to_string()
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct FieldWithContext<'a> {
+    pub field: &'a FieldDescriptorProto,
+    pub message: MessageWithScope<'a>,
+}
+
+impl<'a> FieldWithContext<'a> {
+    #[doc(hidden)]
+    pub fn is_oneof(&self) -> bool {
+        self.field.has_oneof_index()
+    }
+
+    pub fn oneof(&self) -> Option<OneofWithContext<'a>> {
+        if self.is_oneof() {
+            Some(
+                self.message
+                    .oneof_by_index(self.field.get_oneof_index() as u32),
+            )
+        } else {
+            None
+        }
+    }
+
+    pub fn number(&self) -> u32 {
+        self.field.get_number() as u32
+    }
+
+    /// Shortcut
+    pub fn name(&self) -> &str {
+        self.field.get_name()
+    }
+
+    // field name in generated code
+    #[deprecated]
+    pub fn rust_name(&self) -> String {
+        self.field.rust_name()
+    }
+
+    // From field to file root
+    pub fn containing_messages(&self) -> Vec<&'a DescriptorProto> {
+        let mut r = Vec::new();
+        r.push(self.message.message);
+        r.extend(self.message.scope.path.iter().rev());
+        r
+    }
+}
+
+#[derive(Clone)]
+pub struct OneofVariantWithContext<'a> {
+    pub oneof: &'a OneofWithContext<'a>,
+    pub field: &'a FieldDescriptorProto,
+}
+
+#[derive(Clone)]
+pub struct OneofWithContext<'a> {
+    pub oneof: &'a OneofDescriptorProto,
+    pub index: u32,
+    pub message: MessageWithScope<'a>,
+}
+
+impl<'a> OneofWithContext<'a> {
+    /// Oneof rust name
+    pub fn name(&'a self) -> &'a str {
+        match self.oneof.get_name() {
+            "type" => "field_type",
+            "box" => "field_box",
+            x => x,
+        }
+    }
+
+    /// rust type name of enum
+    pub fn rust_name(&self) -> String {
+        format!(
+            "{}_oneof_{}",
+            self.message.rust_name(),
+            self.oneof.get_name()
+        )
+    }
+
+    /// Oneof variants
+    pub fn variants(&'a self) -> Vec<OneofVariantWithContext<'a>> {
+        self.message
+            .fields()
+            .iter()
+            .filter(|f| f.field.has_oneof_index() && f.field.get_oneof_index() == self.index as i32)
+            .map(|f| OneofVariantWithContext {
+                oneof: self,
+                field: &f.field,
+            })
+            .collect()
+    }
+}
+
+/// Find message by rust type name
+pub fn find_message_by_rust_name<'a>(
+    fd: &'a FileDescriptorProto,
+    rust_name: &str,
+) -> MessageWithScope<'a> {
+    FileScope {
+        file_descriptor: fd,
+    }
+    .find_messages()
+    .into_iter()
+    .find(|m| m.rust_name() == rust_name)
+    .unwrap()
+}
+
+/// Find enum by rust type name
+pub fn find_enum_by_rust_name<'a>(
+    fd: &'a FileDescriptorProto,
+    rust_name: &str,
+) -> EnumWithScope<'a> {
+    FileScope {
+        file_descriptor: fd,
+    }
+    .find_enums()
+    .into_iter()
+    .find(|e| e.rust_name() == rust_name)
+    .unwrap()
+}
+
+#[cfg(test)]
+mod test {
+
+    use super::proto_path_to_rust_mod;
+
+    #[test]
+    fn test_mod_path_proto_ext() {
+        assert_eq!("proto", proto_path_to_rust_mod("proto.proto"));
+    }
+
+    #[test]
+    fn test_mod_path_unknown_ext() {
+        assert_eq!("proto_proto3", proto_path_to_rust_mod("proto.proto3"));
+    }
+
+    #[test]
+    fn test_mod_path_empty_ext() {
+        assert_eq!("proto", proto_path_to_rust_mod("proto"));
+    }
+}