Use separate target dir when compiling Wasm code (#1044)

It should help with #971, until a more proper solution is in place.

In my experiments, this brings the time to run `./scripts/run_examples` without having made any changes from 440s down to 39s.

BUILD

@@ -29,7 +29,7 @@ exports_files(["LICENSE"])
 # These files are built via cargo outside of Bazel.
 exports_files(srcs = glob(["target/x86_64-unknown-linux-musl/release/*oak_loader"]))
 
-exports_files(srcs = glob(["target/wasm32-unknown-unknown/release/*.wasm"]))
+exports_files(srcs = glob(["examples/target/wasm32-unknown-unknown/release/*.wasm"]))
 
 # These files are necessary for the backend server in the Aggregator example application.
 exports_files(srcs = glob(["target/release/aggregator_*"]))

examples/abitest/config/BUILD

@@ -25,8 +25,8 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "frontend_module": "//:target/wasm32-unknown-unknown/release/abitest_0_frontend.wasm",
-        "backend_module": "//:target/wasm32-unknown-unknown/release/abitest_1_backend.wasm",
+        "frontend_module": "//:examples/target/wasm32-unknown-unknown/release/abitest_0_frontend.wasm",
+        "backend_module": "//:examples/target/wasm32-unknown-unknown/release/abitest_1_backend.wasm",
     },
     textproto = ":config.textproto",
 )

examples/aggregator/config/BUILD

@@ -26,7 +26,7 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/aggregator.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/aggregator.wasm",
     },
     textproto = ":config.textproto",
 )

examples/chat/config/BUILD

@@ -25,7 +25,7 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/chat.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/chat.wasm",
     },
     textproto = ":config.textproto",
 )

examples/hello_world/config/BUILD

@@ -26,8 +26,8 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/hello_world.wasm",
-        "translator": "//:target/wasm32-unknown-unknown/release/translator.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/hello_world.wasm",
+        "translator": "//:examples/target/wasm32-unknown-unknown/release/translator.wasm",
     },
     textproto = ":config.textproto",
 )

examples/machine_learning/config/BUILD

@@ -25,7 +25,7 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/machine_learning.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/machine_learning.wasm",
     },
     textproto = ":config.textproto",
 )

examples/private_set_intersection/config/BUILD

@@ -25,7 +25,7 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/private_set_intersection.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/private_set_intersection.wasm",
     },
     textproto = ":config.textproto",
 )

examples/running_average/config/BUILD

@@ -25,7 +25,7 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/running_average.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/running_average.wasm",
     },
     textproto = ":config.textproto",
 )

examples/rustfmt/config/BUILD

@@ -25,7 +25,7 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/rustfmt.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/rustfmt.wasm",
     },
     textproto = ":config.textproto",
 )

examples/translator/config/BUILD

@@ -25,7 +25,7 @@ exports_files(srcs = glob(["*.textproto"]))
 serialized_config(
     name = "config",
     modules = {
-        "app": "//:target/wasm32-unknown-unknown/release/translator.wasm",
+        "app": "//:examples/target/wasm32-unknown-unknown/release/translator.wasm",
     },
     textproto = ":config.textproto",
 )

scripts/build_example

@@ -48,16 +48,18 @@ fi
 case "${language}" in
   rust)
     for module in examples/"${EXAMPLE}"/module*/rust/Cargo.toml; do
-      cargo build --release --target=wasm32-unknown-unknown --manifest-path="${module}"
+      # Use a separate target dir for Wasm build artifacts. The precise name is not relevant, but it
+      # should end with `target` so that it gets automatically ignored by our `.gitignore`.
+      cargo build --release --target-dir=examples/target --target=wasm32-unknown-unknown --manifest-path="${module}"
     done
 
     # Serialize application configuration for Rust module.
     if [[ "${EXAMPLE}" == "hello_world" ]]; then
       # `hello_world` example has an optional additional `translator` module.
-      cargo build --release --target=wasm32-unknown-unknown --manifest-path="examples/translator/module/rust/Cargo.toml"
+      cargo build --release --target-dir=examples/target --target=wasm32-unknown-unknown --manifest-path="examples/translator/module/rust/Cargo.toml"
     elif [[ "${EXAMPLE}" == "aggregator" ]]; then
       # `aggregator` example has an additional Backend Docker image
-      cargo build --release --package=aggregator_backend
+      cargo build --release --target=x86_64-unknown-linux-musl --package=aggregator_backend
     fi
     bazel --output_base="${CACHE_DIR}/client" build "${bazel_build_flags[@]}" "//examples/${EXAMPLE}/config:config";;
   cpp)

scripts/build_reproducibility_index

@@ -12,7 +12,7 @@ source "$SCRIPTS_DIR/common"
 
 # List of artifacts that are expected to be reproducibly built.
 readonly REPRODUCIBLE_ARTIFACTS=(
-  ./target/wasm32-unknown-unknown/release/*.wasm
+  ./examples/target/wasm32-unknown-unknown/release/*.wasm
   ./target/x86_64-unknown-linux-musl/release/oak_loader
 )
 

scripts/check_formatting

@@ -16,6 +16,7 @@ find . \
     -not \( -path ./cargo-cache -prune \) -and \
     -not \( -path ./cargo -prune \) -and \
     -not \( -path ./target -prune \) -and \
+    -not \( -path ./examples/target -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name BUILD -or -name WORKSPACE -or -name '*.bzl' \) \
   \) -exec buildifier -lint=warn -mode=check {} +
@@ -27,6 +28,7 @@ readonly MISSING_LICENSES=$(find . \
     -not \( -path ./cargo-cache -prune \) -and \
     -not \( -path ./cargo -prune \) -and \
     -not \( -path ./target -prune \) -and \
+    -not \( -path ./examples/target -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name BUILD \) \
   \) -exec grep --files-without-match '^    licenses = \["notice"\],$' {} +)
@@ -53,7 +55,7 @@ find . \
     -not \( -path ./.git -prune \) -and \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name '*Dockerfile' \) \
   \) -exec hadolint {} +
@@ -63,7 +65,7 @@ find . \
     -not \( -path ./.git -prune \) -and \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name '*.md' -or -name '*.yaml' -or -name '*.toml' \) \
   \) -exec prettier --check {} +
@@ -73,7 +75,7 @@ find . \
     -not \( -path ./.git -prune \) -and \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name '*.md' \) \
   \) -exec markdownlint {} +
@@ -83,7 +85,7 @@ find . \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
     -not \( -path ./cargo -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f \( -name '*.rs' -o -name '*.cc' \) \) \
   \) -exec ./scripts/check_license {} +
@@ -92,7 +94,7 @@ find . \
   \(  \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f \( -name '*.rs' -o -name '*.cc' -o -name '*.proto' -o -name '*.h' \) \) \
   \) -exec ./scripts/check_todo {} +

scripts/format

@@ -15,7 +15,7 @@ find . \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
     -not \( -path ./cargo -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name BUILD -or -name WORKSPACE -or -name '*.bzl' \) \
   \) -exec buildifier -lint=warn -mode=fix {} +
@@ -25,7 +25,7 @@ find . \
     -not \( -path ./.git -prune \) -and \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name '*.h' -or -name '*.cc' -or -name '*.proto' \) \
   \) -exec clang-format -i -style=file {} +
@@ -37,7 +37,7 @@ find . \
     -not \( -path ./.git -prune \) -and \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name '*.md' -or -name '*.yaml' -or -name '*.toml' \) \
   \) -exec prettier --write {} +
@@ -47,7 +47,7 @@ find . \
     -not \( -path ./.git -prune \) -and \
     -not \( -path ./bazel-cache -prune \) -and \
     -not \( -path ./cargo-cache -prune \) -and \
-    -not \( -path ./target -prune \) -and \
+    -not \( -path '*/target' -prune \) -and \
     -not \( -path ./third_party -prune \) \
     \( -type f -name '*.md' \) \
   \) -exec markdownlint --fix {} +

sdk/rust/oak_tests/Cargo.toml

@@ -7,7 +7,6 @@ license = "Apache-2.0"
 
 [dependencies]
 byteorder = "*"
-cargo_metadata = "*"
 lazy_static = "*"
 log = { version = "*", features = ["std"] }
 oak = "=0.1.0"

sdk/rust/oak_tests/src/lib.rs

@@ -22,32 +22,38 @@ use oak_abi::proto::oak::application::{
     WebAssemblyConfiguration,
 };
 use prost::Message;
-use std::{collections::HashMap, process::Command};
+use std::{collections::HashMap, path::PathBuf, process::Command};
 use tonic::transport::Certificate;
 
 // TODO(#544): re-enable unit tests of SDK functionality
 
 /// Uses cargo to compile a Rust manifest to Wasm bytes.
 pub fn compile_rust_wasm(cargo_path: &str, module_name: &str) -> std::io::Result<Vec<u8>> {
-    let mut cmd = cargo_metadata::MetadataCommand::new();
-    cmd.manifest_path(cargo_path);
-    let metadata = cmd.exec().unwrap();
+    // Use a separate target dir for Wasm build artifacts. The precise name is not relevant, but it
+    // should end with `target` so that it gets automatically ignored by our `.gitignore`.
+    let target_dir = PathBuf::from("oak_tests/target");
 
     Command::new("cargo")
         .args(&[
             "build",
+            &format!(
+                "--target-dir={}",
+                target_dir.to_str().expect("invalid target dir")
+            ),
             "--target=wasm32-unknown-unknown",
             &format!("--manifest-path={}", cargo_path),
         ])
         .env_remove("RUSTFLAGS")
         .spawn()?
         .wait()?;
 
-    let mut path = metadata.target_directory;
-    path.push("wasm32-unknown-unknown/debug");
-    path.push(module_name);
+    let mut module_path = target_dir;
+    module_path.push("wasm32-unknown-unknown/debug");
+    module_path.push(module_name);
 
-    std::fs::read(path)
+    info!("compiled Wasm module path: {:?}", module_path);
+
+    std::fs::read(module_path)
 }
 
 const DEFAULT_ENTRYPOINT_NAME: &str = "oak_main";