protoc-gen-rust-grpc: Fix well-known protos for prost

examples/Cargo.toml

@@ -324,3 +324,4 @@ grpc = { path = "../grpc", optional = true }
 [build-dependencies]
 tonic-prost-build = { path = "../tonic-prost-build" }
 grpc-protobuf-build = { path = "../grpc-protobuf-build", default-features = false }
+protoc-gen-rust-grpc = { path = "../protoc-gen-rust-grpc", optional = true }

examples/README.md

@@ -2,8 +2,17 @@
 
 Set of examples that show off the features provided by `tonic` and `grpc`.
 
-In order to build these examples, you must have the `protoc` Protocol Buffers compiler
-installed, along with the Protocol Buffers resource files.
+In order to build these examples, you must have the `protoc` Protocol Buffers
+compiler.  You need to have installed either:
+
+ * the `protoc` binary, made available in your PATH. This is the default.
+
+ * A compatible C++ compiler and CMake as described in the
+   [`protoc-gen-rust-grpc` crate](../protoc-gen-rust-grpc/README.md).  Choose
+   this option by passing `--features protoc-gen-rust-grpc` to `cargo`.
+
+If you choose to install protobuf, here are the steps for a variety of operating
+systems.
 
 Ubuntu:
 
@@ -28,16 +37,18 @@ brew install protobuf
 
 # `grpc` crate examples
 
-For the examples related to the `grpc` crate, the protobuf generated code is not
-regenerated by default when running `cargo`.  Instead you must set
-`GRPC_RUST_REGENERATE_PROTO=1` in your environment.  This requires that you have
-the `protoc-gen-rust-grpc` binary installed in your path.  This can be
-downloaded from [our releases].
+For the examples related to the `grpc` crate, the generated code is checked into
+the repo to allow building without `protoc`.  To rebuild the generated code you
+must set `GRPC_RUST_REGENERATE_PROTO=1` in your environment.  This requires that
+you have installed either:
+
+ * the `protoc` and `protoc-gen-rust-grpc` binaries, made available in your
+   PATH.  See above for `protoc`.  `protoc-gen-rust-grpc` can be downloaded from
+   [our releases].
 
-Alternatively, you can also set the `grpc-protobuf-build/build-plugin` feature
-flag when building via `cargo` using the `--features` flag.  In this case you
-will need a compatible C++ compiler and CMake as described in the
-`protoc-gen-rust-grpc` crate.
+ * A compatible C++ compiler and CMake as described in the
+   [`protoc-gen-rust-grpc` crate](../protoc-gen-rust-grpc/README.md).  Choose
+   this option by passing `--features grpc-protobuf-build/build-plugin` to `cargo`.
 
 [our releases]: https://github.com/grpc/grpc-rust/releases
 

examples/build.rs

@@ -2,6 +2,17 @@ use std::{env, path::PathBuf};
 
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
+
+    // Optionally use protoc-gen-rust-grpc's protoc for prost. protoc-gen-rust-grpc will skip its
+    // build when PROTOC_GEN_RUST_GRPC_NO_BUILD=1 (used in gRPC's CI), so we check that the binary
+    // exists.
+    #[cfg(feature = "protoc-gen-rust-grpc")]
+    if protoc_gen_rust_grpc::protoc().exists() {
+        unsafe {
+            env::set_var("PROTOC", protoc_gen_rust_grpc::protoc());
+        }
+    }
+
     tonic_prost_build::configure()
         .compile_protos(&["proto/routeguide/route_guide.proto"], &["proto"])
         .unwrap();

grpc-protobuf-build/src/lib.rs

@@ -260,8 +260,8 @@ impl CodeGen {
         // 2. Compiled via protoc-gen-rust-grpc (build-plugin feature)
         #[cfg(feature = "build-plugin")]
         {
-            let compiled_protoc = PathBuf::from(protoc_gen_rust_grpc::protoc());
-            let compiled_plugin = PathBuf::from(protoc_gen_rust_grpc::protoc_gen_rust_grpc());
+            let compiled_protoc = protoc_gen_rust_grpc::protoc();
+            let compiled_plugin = protoc_gen_rust_grpc::protoc_gen_rust_grpc();
             if compiled_protoc.exists() && compiled_plugin.exists() {
                 // The files may not exist if a build setting instructed protoc-gen-rust-grpc to
                 // skip the C++ build (DOCS_RS / our CI setting).

protoc-gen-rust-grpc/src/cpp_source/CMakeLists.txt

@@ -126,6 +126,11 @@ if(BUILD_PROTOC)
     install(PROGRAMS ${CMAKE_BINARY_DIR}/bin/${PROTOC_OUTPUT_NAME}
         DESTINATION bin
     )
+
+    install(DIRECTORY ${protobuf_SOURCE_DIR}/src/google/protobuf/
+        DESTINATION include/google/protobuf
+        FILES_MATCHING PATTERN "*.proto"
+    )
 endif()
 
 # Print summary

protoc-gen-rust-grpc/src/lib.rs

@@ -29,33 +29,26 @@
 
 use std::path::PathBuf;
 
-fn bin_file(file: &str) -> String {
-    let mut path = PathBuf::from(bin()).join(file);
+fn bin_file(file: &str) -> PathBuf {
+    let mut path = bin().join(file);
     if cfg!(target_os = "windows") {
         path.set_extension("exe");
     }
-    path.to_str()
-        .expect("Path contains invalid UTF-8")
-        .to_owned()
+    path
 }
 
 /// The full path to the `protoc` executable.
-pub fn protoc() -> String {
+pub fn protoc() -> PathBuf {
     bin_file("protoc")
 }
 
 /// The full path to the gRPC `protoc` plugin, `protoc-gen-rust-grpc`.
-pub fn protoc_gen_rust_grpc() -> String {
+pub fn protoc_gen_rust_grpc() -> PathBuf {
     bin_file("protoc-gen-rust-grpc")
 }
 
 /// The path to the `bin` directory containing the C++ binaries this package
 /// builds.
-pub fn bin() -> String {
-    PathBuf::from(env!("OUT_DIR"))
-        .join("build")
-        .join("bin")
-        .to_str()
-        .expect("Path contains invalid UTF-8")
-        .to_owned()
+pub fn bin() -> PathBuf {
+    PathBuf::from(env!("OUT_DIR")).join("bin")
 }