Use a ninja variable for Protoc binary (#2345)

* Use a ninja variable for Protoc binary

* fix whitespace

.cargo/config.toml

@@ -1,7 +1,7 @@
 [env]
 STRINGS_JSON = { value = "out/rslib/i18n/strings.json", relative = true }
 # build script will append .exe if necessary
-PROTOC = { value = "out/extracted/protoc/bin/protoc", relative = true }
+PROTOC_BINARY = { value = "out/extracted/protoc/bin/protoc", relative = true }
 PYO3_NO_PYTHON = "1"
 MACOSX_DEPLOYMENT_TARGET = "10.13.4"
 

CONTRIBUTORS

@@ -109,6 +109,7 @@ Zoom <zoomrmc+git@gmail.com>
 TRIAEIOU <github.com/TRIAEIOU>
 Stefan Kangas <stefankangas@gmail.com>
 Fabricio Duarte <fabricio.duarte.jr@gmail.com>
+Mani <github.com/krmanik>
 
 ********************
 

build/configure/src/proto.rs

@@ -1,6 +1,8 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
+use std::env;
+
 use ninja_gen::archives::download_and_extract;
 use ninja_gen::archives::with_exe;
 use ninja_gen::glob;
@@ -10,16 +12,31 @@ use ninja_gen::protobuf::protoc_archive;
 use ninja_gen::protobuf::ClangFormat;
 use ninja_gen::Build;
 use ninja_gen::Result;
+use ninja_gen::Utf8Path;
 
-pub fn download_protoc(build: &mut Build) -> Result<()> {
-    download_and_extract(
-        build,
-        "protoc",
-        protoc_archive(build.host_platform),
-        hashmap! {
-            "bin" => [with_exe("bin/protoc")]
-        },
-    )?;
+pub fn setup_protoc(build: &mut Build) -> Result<()> {
+    let protoc_binary = match env::var("PROTOC_BINARY") {
+        Ok(path) => {
+            assert!(
+                Utf8Path::new(&path).is_absolute(),
+                "PROTOC_BINARY must be absolute"
+            );
+            path.into()
+        }
+        Err(_) => {
+            download_and_extract(
+                build,
+                "protoc",
+                protoc_archive(build.host_platform),
+                hashmap! {
+                    "bin" => [with_exe("bin/protoc")]
+                },
+            )?;
+            inputs![":extract:protoc:bin"]
+        }
+    };
+    let protoc_binary = build.expand_inputs(protoc_binary);
+    build.variable("protoc_binary", &protoc_binary[0]);
     Ok(())
 }
 

build/configure/src/python.rs

@@ -178,7 +178,7 @@ impl BuildAction for GenPythonProto {
             })
             .collect();
         build.add_inputs("in", &self.proto_files);
-        build.add_inputs("protoc", inputs![":extract:protoc:bin"]);
+        build.add_inputs("protoc", inputs!["$protoc_binary"]);
         build.add_inputs("protoc-gen-mypy", inputs![":pyenv:protoc-gen-mypy"]);
         build.add_outputs("", python_outputs);
     }

build/configure/src/rust.rs

@@ -14,11 +14,11 @@ use ninja_gen::Build;
 use ninja_gen::Result;
 
 use crate::platform::overriden_rust_target_triple;
-use crate::proto::download_protoc;
+use crate::proto::setup_protoc;
 
 pub fn build_rust(build: &mut Build) -> Result<()> {
     prepare_translations(build)?;
-    download_protoc(build)?;
+    setup_protoc(build)?;
     build_rsbridge(build)
 }
 
@@ -79,7 +79,7 @@ fn build_rsbridge(build: &mut Build) -> Result<()> {
         CargoBuild {
             inputs: inputs![
                 glob!["{pylib/rsbridge/**,rslib/**,proto/**}"],
-                ":extract:protoc:bin",
+                "$protoc_binary",
                 // declare a dependency on i18n so it gets built first, allowing
                 // things depending on strings.json to build faster, and ensuring
                 // changes to the ftl files trigger a rebuild

docs/linux.md

@@ -76,9 +76,9 @@ There are a few things to be aware of:
 
 ## Packaging considerations
 
-Python and node are downloaded as part of the build. You can optionally define
-PYTHON_BINARY as the full path to a Python binary, to use it instead of the downloaded
-version. A similar approach could be done with node in the future; a PR would be
+Python, node and protoc are downloaded as part of the build. You can optionally define
+PYTHON_BINARY and PROTOC_BINARY as the full path to a Python binary and Protoc binary respectively,
+to use it instead of the downloaded version. A similar approach could be done with node in the future; a PR would be
 welcome.
 
 If rust-toolchain.toml is removed, newer Rust versions can be used. Older versions

rslib/build/protobuf.rs

@@ -125,7 +125,8 @@ pub fn write_backend_proto_rs() {
 /// If PROTOC is not defined, and protoc is not on path, use the protoc
 /// fetched by Bazel so that Rust Analyzer does not fail.
 fn maybe_add_protobuf_to_path() {
-    if let Ok(protoc) = env::var("PROTOC") {
+    if let Ok(protoc) = env::var("PROTOC_BINARY") {
+        env::set_var("PROTOC", &protoc);
         if cfg!(windows) && !protoc.ends_with(".exe") {
             env::set_var("PROTOC", format!("{protoc}.exe"));
         }