Import protobuf-codegen-2.14.0

* Add OWNERS, Android.bp, and README.android.
* Hard code version number in src/lib.rs for now.
  It could be in a smarter update_package.sh to get the
  new version number from Cargo.tom. But until then,
  the difference in lib.rs will be caught and fixed manually.
* Rename protoc_gen_rust to protoc-gen-rust for aprotoc plugin.

Bug: 143953733
Test: make
Change-Id: I9b3c3b9f2e7ad0eb203c26534f2b6ba5fac46eef
diff --git a/src/code_writer.rs b/src/code_writer.rs
new file mode 100644
index 0000000..61ce92f
--- /dev/null
+++ b/src/code_writer.rs
@@ -0,0 +1,383 @@
+// TODO: used by grpc-rust, should move it into separate crate.
+#![doc(hidden)]
+
+use std::io::Write;
+
+/// Field visibility.
+pub enum Visibility {
+    Public,
+    Default,
+}
+
+pub struct CodeWriter<'a> {
+    writer: &'a mut (dyn Write + 'a),
+    indent: String,
+}
+
+impl<'a> CodeWriter<'a> {
+    pub fn new(writer: &'a mut dyn Write) -> CodeWriter<'a> {
+        CodeWriter {
+            writer: writer,
+            indent: "".to_string(),
+        }
+    }
+
+    pub fn write_line<S: AsRef<str>>(&mut self, line: S) {
+        (if line.as_ref().is_empty() {
+            self.writer.write_all("\n".as_bytes())
+        } else {
+            let s: String = [self.indent.as_ref(), line.as_ref(), "\n"].concat();
+            self.writer.write_all(s.as_bytes())
+        })
+        .unwrap();
+    }
+
+    pub fn write_generated(&mut self) {
+        self.write_line("// This file is generated. Do not edit");
+        self.write_generated_common();
+    }
+
+    pub fn write_generated_by(&mut self, pkg: &str, version: &str) {
+        self.write_line(format!(
+            "// This file is generated by {pkg} {version}. Do not edit",
+            pkg = pkg,
+            version = version
+        ));
+        self.write_generated_common();
+    }
+
+    fn write_generated_common(&mut self) {
+        // https://secure.phabricator.com/T784
+        self.write_line("// @generated");
+
+        self.write_line("");
+        self.comment("https://github.com/rust-lang/rust-clippy/issues/702");
+        self.write_line("#![allow(unknown_lints)]");
+        self.write_line("#![allow(clippy::all)]");
+        self.write_line("");
+        self.write_line("#![cfg_attr(rustfmt, rustfmt_skip)]");
+        self.write_line("");
+        self.write_line("#![allow(box_pointers)]");
+        self.write_line("#![allow(dead_code)]");
+        self.write_line("#![allow(missing_docs)]");
+        self.write_line("#![allow(non_camel_case_types)]");
+        self.write_line("#![allow(non_snake_case)]");
+        self.write_line("#![allow(non_upper_case_globals)]");
+        self.write_line("#![allow(trivial_casts)]");
+        self.write_line("#![allow(unsafe_code)]");
+        self.write_line("#![allow(unused_imports)]");
+        self.write_line("#![allow(unused_results)]");
+    }
+
+    pub fn todo(&mut self, message: &str) {
+        self.write_line(format!("panic!(\"TODO: {}\");", message));
+    }
+
+    pub fn unimplemented(&mut self) {
+        self.write_line(format!("unimplemented!();"));
+    }
+
+    pub fn indented<F>(&mut self, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        cb(&mut CodeWriter {
+            writer: self.writer,
+            indent: format!("{}    ", self.indent),
+        });
+    }
+
+    #[allow(dead_code)]
+    pub fn commented<F>(&mut self, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        cb(&mut CodeWriter {
+            writer: self.writer,
+            indent: format!("// {}", self.indent),
+        });
+    }
+
+    pub fn pub_const(&mut self, name: &str, field_type: &str, init: &str) {
+        self.write_line(&format!("pub const {}: {} = {};", name, field_type, init));
+    }
+
+    pub fn lazy_static(&mut self, name: &str, ty: &str) {
+        self.lazy_static_protobuf_path(name, ty, "::protobuf")
+    }
+
+    pub fn lazy_static_protobuf_path(&mut self, name: &str, ty: &str, protobuf_crate_path: &str) {
+        self.write_line(&format!(
+            "static mut {}: {}::lazy::Lazy<{}> = {}::lazy::Lazy::INIT;",
+            name, protobuf_crate_path, ty, protobuf_crate_path,
+        ));
+    }
+
+    pub fn lazy_static_decl_get<F>(&mut self, name: &str, ty: &str, init: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.lazy_static(name, ty);
+        self.unsafe_expr(|w| {
+            w.write_line(&format!("{}.get(|| {{", name));
+            w.indented(|w| init(w));
+            w.write_line(&format!("}})"));
+        });
+    }
+
+    pub fn lazy_static_decl_get_simple(&mut self, name: &str, ty: &str, init: &str) {
+        self.lazy_static(name, ty);
+        self.unsafe_expr(|w| {
+            w.write_line(&format!("{}.get({})", name, init));
+        });
+    }
+
+    pub fn block<F>(&mut self, first_line: &str, last_line: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.write_line(first_line);
+        self.indented(cb);
+        self.write_line(last_line);
+    }
+
+    pub fn expr_block<F>(&mut self, prefix: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.block(&format!("{} {{", prefix), "}", cb);
+    }
+
+    pub fn stmt_block<S: AsRef<str>, F>(&mut self, prefix: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.block(&format!("{} {{", prefix.as_ref()), "};", cb);
+    }
+
+    pub fn unsafe_expr<F>(&mut self, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block("unsafe", cb);
+    }
+
+    pub fn impl_self_block<S: AsRef<str>, F>(&mut self, name: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("impl {}", name.as_ref()), cb);
+    }
+
+    pub fn impl_for_block<S1: AsRef<str>, S2: AsRef<str>, F>(&mut self, tr: S1, ty: S2, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.impl_args_for_block(&[], tr.as_ref(), ty.as_ref(), cb);
+    }
+
+    pub fn impl_args_for_block<F>(&mut self, args: &[&str], tr: &str, ty: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        let args_str = if args.is_empty() {
+            "".to_owned()
+        } else {
+            format!("<{}>", args.join(", "))
+        };
+        self.expr_block(&format!("impl{} {} for {}", args_str, tr, ty), cb);
+    }
+
+    pub fn unsafe_impl(&mut self, what: &str, for_what: &str) {
+        self.write_line(&format!("unsafe impl {} for {} {{}}", what, for_what));
+    }
+
+    pub fn pub_struct<S: AsRef<str>, F>(&mut self, name: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("pub struct {}", name.as_ref()), cb);
+    }
+
+    pub fn def_struct<S: AsRef<str>, F>(&mut self, name: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("struct {}", name.as_ref()), cb);
+    }
+
+    pub fn pub_enum<F>(&mut self, name: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("pub enum {}", name), cb);
+    }
+
+    pub fn pub_trait<F>(&mut self, name: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("pub trait {}", name), cb);
+    }
+
+    pub fn pub_trait_extend<F>(&mut self, name: &str, extend: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("pub trait {} : {}", name, extend), cb);
+    }
+
+    pub fn field_entry(&mut self, name: &str, value: &str) {
+        self.write_line(&format!("{}: {},", name, value));
+    }
+
+    pub fn field_decl(&mut self, name: &str, field_type: &str) {
+        self.write_line(&format!("{}: {},", name, field_type));
+    }
+
+    pub fn pub_field_decl(&mut self, name: &str, field_type: &str) {
+        self.write_line(&format!("pub {}: {},", name, field_type));
+    }
+
+    pub fn field_decl_vis(&mut self, vis: Visibility, name: &str, field_type: &str) {
+        match vis {
+            Visibility::Public => self.pub_field_decl(name, field_type),
+            Visibility::Default => self.field_decl(name, field_type),
+        }
+    }
+
+    pub fn derive(&mut self, derive: &[&str]) {
+        let v: Vec<String> = derive.iter().map(|&s| s.to_string()).collect();
+        self.write_line(&format!("#[derive({})]", v.join(",")));
+    }
+
+    pub fn allow(&mut self, what: &[&str]) {
+        let v: Vec<String> = what.iter().map(|&s| s.to_string()).collect();
+        self.write_line(&format!("#[allow({})]", v.join(",")));
+    }
+
+    pub fn comment(&mut self, comment: &str) {
+        if comment.is_empty() {
+            self.write_line("//");
+        } else {
+            self.write_line(&format!("// {}", comment));
+        }
+    }
+
+    pub fn fn_def(&mut self, sig: &str) {
+        self.write_line(&format!("fn {};", sig));
+    }
+
+    pub fn fn_block<F>(&mut self, public: bool, sig: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        if public {
+            self.expr_block(&format!("pub fn {}", sig), cb);
+        } else {
+            self.expr_block(&format!("fn {}", sig), cb);
+        }
+    }
+
+    pub fn pub_fn<F>(&mut self, sig: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.fn_block(true, sig, cb);
+    }
+
+    pub fn def_fn<F>(&mut self, sig: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.fn_block(false, sig, cb);
+    }
+
+    pub fn def_mod<F>(&mut self, name: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("mod {}", name), cb)
+    }
+
+    pub fn pub_mod<F>(&mut self, name: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("pub mod {}", name), cb)
+    }
+
+    pub fn while_block<S: AsRef<str>, F>(&mut self, cond: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("while {}", cond.as_ref()), cb);
+    }
+
+    // if ... { ... }
+    pub fn if_stmt<S: AsRef<str>, F>(&mut self, cond: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("if {}", cond.as_ref()), cb);
+    }
+
+    // if ... {} else { ... }
+    pub fn if_else_stmt<S: AsRef<str>, F>(&mut self, cond: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.write_line(&format!("if {} {{", cond.as_ref()));
+        self.write_line("} else {");
+        self.indented(cb);
+        self.write_line("}");
+    }
+
+    // if let ... = ... { ... }
+    pub fn if_let_stmt<F>(&mut self, decl: &str, expr: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.if_stmt(&format!("let {} = {}", decl, expr), cb);
+    }
+
+    // if let ... = ... { } else { ... }
+    pub fn if_let_else_stmt<F>(&mut self, decl: &str, expr: &str, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.if_else_stmt(&format!("let {} = {}", decl, expr), cb);
+    }
+
+    pub fn for_stmt<S1: AsRef<str>, S2: AsRef<str>, F>(&mut self, over: S1, varn: S2, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.stmt_block(&format!("for {} in {}", varn.as_ref(), over.as_ref()), cb)
+    }
+
+    pub fn match_block<S: AsRef<str>, F>(&mut self, value: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.stmt_block(&format!("match {}", value.as_ref()), cb);
+    }
+
+    pub fn match_expr<S: AsRef<str>, F>(&mut self, value: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.expr_block(&format!("match {}", value.as_ref()), cb);
+    }
+
+    pub fn case_block<S: AsRef<str>, F>(&mut self, cond: S, cb: F)
+    where
+        F: Fn(&mut CodeWriter),
+    {
+        self.block(&format!("{} => {{", cond.as_ref()), "},", cb);
+    }
+
+    pub fn case_expr<S1: AsRef<str>, S2: AsRef<str>>(&mut self, cond: S1, body: S2) {
+        self.write_line(&format!("{} => {},", cond.as_ref(), body.as_ref()));
+    }
+}