Switch from rust-toolchain to rust-toolchain.toml so we can specify components

c2rust-transpile/rust-toolchain.toml

@@ -0,0 +1 @@
+../rust-toolchain.toml

c2rust-transpile/src/build_files/mod.rs

@@ -259,8 +259,8 @@ fn emit_lib_rs(
 /// If we translate variadic functions, the output will only compile
 /// on a nightly toolchain until the `c_variadics` feature is stable.
 fn emit_rust_toolchain(tcfg: &TranspilerConfig, build_dir: &Path) {
-    let output_path = build_dir.join("rust-toolchain");
-    let output = include_str!("../../../rust-toolchain").to_string();
+    let output_path = build_dir.join("rust-toolchain.toml");
+    let output = include_str!("../../rust-toolchain.toml").to_string();
     maybe_write_to_file(&output_path, output, tcfg.overwrite_existing);
 }
 

c2rust/rust-toolchain.toml

@@ -0,0 +1 @@
+../rust-toolchain.toml

docker/Dockerfile

@@ -1,6 +1,6 @@
 # Docker image for c2rust CI and containerized development.
 # Multi-distro via optional BASE_IMAGE argument.
-# RUST_VER argument should be set to the contents of the rust-toolchain file in
+# RUST_VER argument should be set to the channel of the rust-toolchain.toml file in
 # the repo root (because dockerfiles can't access files above the location where
 # `docker build` is run).
 

docs/README-developers.md

@@ -27,7 +27,7 @@ Then run `./scripts/provision_mac.sh`.
   - `python-dev`
   - `python` >= 3.6
   - [python dependencies](../scripts/requirements.txt)
-  - `rustc` [version](../rust-toolchain)
+  - `rustc` [version](../rust-toolchain.toml)
   - `rustfmt-preview` component for the above `rustc` version
   - `libssl` (development library, dependency of the refactoring tool)
 

dynamic_instrumentation/Cargo.toml

@@ -15,6 +15,9 @@ fs-err = "2"
 clap = { version = "3.2", features = ["derive"] }
 cargo_metadata = "0.15"
 camino = "1.0"
+# Used for parsing `rust-toolchain.toml`.
+# We don't need to edit at all, but `cargo` uses `toml-edit`, so we want to match it.
+toml_edit = "0.14"
 
 [build-dependencies]
 rustc-private-link = { path = "../rustc-private-link" }

dynamic_instrumentation/rust-toolchain.toml

@@ -0,0 +1 @@
+../rust-toolchain.toml

dynamic_instrumentation/src/main.rs

@@ -268,15 +268,27 @@ fn rustc_wrapper() -> anyhow::Result<()> {
     Ok(())
 }
 
+/// Set `$RUST_TOOLCHAIN` to the toolchain channel specified in `rust-toolchain.toml`.
+/// This ensures that we use a toolchain compatible with the `rustc` private crates that we linked to.
+fn set_rust_toolchain() -> anyhow::Result<()> {
+    let toml = include_str!("../rust-toolchain.toml");
+    // Couldn't find an `include_toml!` macro to do this at compile time.
+    let doc = toml.parse::<toml_edit::Document>()?;
+    let channel = doc["toolchain"]["channel"].as_str();
+    if let Some(toolchain) = channel {
+        env::set_var("RUSTUP_TOOLCHAIN", toolchain);
+    }
+    Ok(())
+}
+
 /// Run as a `cargo` wrapper/plugin, the default invocation.
 fn cargo_wrapper(rustc_wrapper: &Path) -> anyhow::Result<()> {
     let Args {
         metadata,
         mut cargo_args,
     } = Args::parse();
 
-    // Ensure we use a toolchain compatible with the `rustc` private crates we linked to.
-    env::set_var("RUSTUP_TOOLCHAIN", include_str!("../rust-toolchain").trim());
+    set_rust_toolchain()?;
 
     // Resolve the sysroot once in the [`cargo_wrapper`]
     // so that we don't need all of the [`rustc_wrapper`]s to have to do it.

examples/robotfindskitten/repo/rust/rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly-2022-02-14"

manual/rust-toolchain.toml

@@ -0,0 +1 @@
+../rust-toolchain.toml

rust-toolchain.toml

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "nightly-2022-02-14"
+components = ["rustfmt-preview", "rustc-dev", "rust-src"]

scripts/common.py

@@ -11,11 +11,13 @@
 import platform
 import multiprocessing
 
-from typing import List, Callable
+from pathlib import Path
+from typing import List
 
 import plumbum as pb
 
 from plumbum.machines import LocalCommand as Command
+from query_toml import query_toml
 
 
 class Colors:
@@ -99,9 +101,7 @@ class Config:
 
     CC_DB_JSON = "compile_commands.json"
 
-    # Look up rust toolchain from repo root
-    with open(os.path.join(ROOT_DIR, "rust-toolchain")) as fh:
-        CUSTOM_RUST_NAME = fh.readline().strip()
+    CUSTOM_RUST_NAME = query_toml(path=Path(ROOT_DIR).joinpath("rust-toolchain.toml"), query=("toolchain", "channel"))
 
     LLVM_SKIP_SIGNATURE_CHECKS  = False
 

scripts/docker_build.sh

@@ -27,9 +27,9 @@ build_image() {
     BASE_IMAGE=${1}
     IMAGE_TAG=$(echo ${BASE_IMAGE} | tr -s :/ - ) # replace colons and slashes with hyphens
 
-    # pull the rust version out of ../rust-toolchain to keep things synched
-    RUST_TOOLCHAIN_FILE="$SCRIPT_DIR/../rust-toolchain"
-    RUST_VER=$(cat $RUST_TOOLCHAIN_FILE | tr -d '\n')
+    # pull the rust version out of ../rust-toolchain.toml to keep things synced
+    RUST_TOOLCHAIN_FILE="$SCRIPT_DIR/../rust-toolchain.toml"
+    RUST_VER=$($SCRIPT_DIR/query_toml.py toolchain.channel $RUST_TOOLCHAIN_FILE)
 
     docker pull "$BASE_IMAGE"
     docker build -f $SCRIPT_DIR/../docker/Dockerfile \

scripts/provision_mac.sh

@@ -34,10 +34,7 @@ type -P "pip3" >/dev/null || {
 pip3 install --user --upgrade pip
 pip3 install -r "$SCRIPT_DIR/requirements.txt" --user --disable-pip-version-check
 
-RUST_TOOLCHAIN_FILE="$SCRIPT_DIR/../rust-toolchain"
-export RUST_VER=$(cat $RUST_TOOLCHAIN_FILE | tr -d '\n')
-
 # Rust and dependencies
-RUST_TOOLCHAIN_FILE="$SCRIPT_DIR/../rust-toolchain"
-export RUST_VER=$(cat $RUST_TOOLCHAIN_FILE | tr -d '\n')
+RUST_TOOLCHAIN_FILE="$SCRIPT_DIR/../rust-toolchain.toml"
+export RUST_VER=$($SCRIPT_DIR/query_toml.py toolchain.channel $RUST_TOOLCHAIN_FILE)
 "$SCRIPT_DIR/provision_rust.sh"

scripts/query_toml.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+
+from argparse import ArgumentParser
+from pathlib import Path
+from typing import Any, Iterable
+import toml
+
+
+def query_toml(path: Path, query: Iterable[str]) -> Any:
+    result = toml.load(path)
+    for field in query:
+        if isinstance(result, list):
+            field = int(field)
+        result = result[field]
+    return result
+
+
+def main():
+    parser = ArgumentParser()
+    parser.add_argument("query", type=str, help="the TOML query, with fields separated by .")
+    parser.add_argument("path", type=Path, help="the path to a TOML file")
+    args = parser.parse_args()
+    print(query_toml(path=args.path, query=args.query.split(".")))
+
+
+if __name__ == "__main__":
+    main()

scripts/requirements.txt

@@ -9,3 +9,4 @@ pygments
 typing;python_version<"3.5"
 scan-build
 pyyaml
+toml

scripts/test_rust_refactor.py

@@ -91,7 +91,7 @@ def main():
 
     setup_logging()
     # NOTE: it seems safe to disable this check since we now
-    # that we use a rust-toolchain file for rustc versioning.
+    # that we use a rust-toolchain.toml file for rustc versioning.
     # ensure_rustc_version(c.CUSTOM_RUST_RUSTC_VERSION)
     # TODO: update rustfmt version check once c2rust-refactor bitrot has been fixed
     # ensure_rustfmt_version()

scripts/test_translator.py

@@ -422,7 +422,7 @@ def run(self) -> List[TestOutcome]:
                 self.generated_files["rust_src"].append(self.full_path + "/src/Cargo.toml")
                 self.generated_files["rust_src"].append(self.full_path + "/src/build.rs")
                 self.generated_files["rust_src"].append(self.full_path + "/src/c2rust-lib.rs")
-                self.generated_files["rust_src"].append(self.full_path + "/src/rust-toolchain")
+                self.generated_files["rust_src"].append(self.full_path + "/src/rust-toolchain.toml")
 
             _, rust_file_short = os.path.split(translated_rust_file.path)
             extensionless_rust_file, _ = os.path.splitext(rust_file_short)
@@ -657,7 +657,7 @@ def main() -> None:
             die(msg, errno.ENOENT)
 
     # NOTE: it seems safe to disable this check since we now
-    # that we use a rust-toolchain file for rustc versioning.
+    # that we use a rust-toolchain.toml file for rustc versioning.
     # ensure_rustc_version(c.CUSTOM_RUST_RUSTC_VERSION)
 
     if not test_directories: