Do not overwrite original config.toml in opt-dist

So that follow-up CI commands can proceed normally. It will also avoid overwriting `config.toml` when running opt-dist tests locally.

Author: Kobzol

src/tools/opt-dist/src/tests.rs

@@ -1,3 +1,5 @@
+use std::path::Path;
+
 use anyhow::Context;
 use camino::{Utf8Path,Utf8PathBuf};
 
@@ -86,36 +88,57 @@ llvm-config = "{llvm_config}"
  log::info!("Using following `config.toml` for running tests:\n{config_content}");
 
 // Simulate a stage 0 compiler with the extracted optimized dist artifacts.
- std::fs::write("config.toml", config_content)?;
-
-let x_py = env.checkout_path().join("x.py");
-letmut args = vec![
- env.python_binary(),
- x_py.as_str(),
-"test",
-"--build",
- env.host_tuple(),
-"--stage",
-"0",
-"tests/assembly",
-"tests/codegen",
-"tests/codegen-units",
-"tests/incremental",
-"tests/mir-opt",
-"tests/pretty",
-"tests/run-make/glibc-symbols-x86_64-unknown-linux-gnu",
-"tests/ui",
-"tests/crashes",
-];
-for test_path in env.skipped_tests(){
- args.extend(["--skip", test_path]);
+with_backed_up_file(Path::new("config.toml"),&config_content, || {
+let x_py = env.checkout_path().join("x.py");
+letmut args = vec![
+ env.python_binary(),
+ x_py.as_str(),
+"test",
+"--build",
+ env.host_tuple(),
+"--stage",
+"0",
+"tests/assembly",
+"tests/codegen",
+"tests/codegen-units",
+"tests/incremental",
+"tests/mir-opt",
+"tests/pretty",
+"tests/run-make/glibc-symbols-x86_64-unknown-linux-gnu",
+"tests/ui",
+"tests/crashes",
+];
+for test_path in env.skipped_tests(){
+ args.extend(["--skip", test_path]);
+}
+cmd(&args)
+.env("COMPILETEST_FORCE_STAGE0","1")
+// Also run dist-only tests
+.env("COMPILETEST_ENABLE_DIST_TESTS","1")
+.run()
+.context("Cannot execute tests")
+})
+}
+
+/// Backup `path` (if it exists), then write `contents` into it, and then restore the original
+/// contents of the file.
+fnwith_backed_up_file<F>(path:&Path,contents:&str,func:F) -> anyhow::Result<()>
+where
+F:FnOnce() -> anyhow::Result<()>,
+{
+let original_contents =
+if path.is_file(){Some(std::fs::read_to_string(path)?)}else{None};
+
+// Overwrite it with new contents
+ std::fs::write(path, contents)?;
+
+let ret = func();
+
+ifletSome(original_contents) = original_contents {
+ std::fs::write(path, original_contents)?;
 }
-cmd(&args)
-.env("COMPILETEST_FORCE_STAGE0","1")
-// Also run dist-only tests
-.env("COMPILETEST_ENABLE_DIST_TESTS","1")
-.run()
-.context("Cannot execute tests")
+
+ ret
 }
 
 /// Tries to find the version of the dist artifacts (either nightly, beta, or 1.XY.Z).