add optional build components for the test environment

Author: lqd

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

@@ -25,6 +25,27 @@ pub struct Environment {
     prebuilt_rustc_perf: Option<Utf8PathBuf>,
     use_bolt: bool,
     shared_llvm: bool,
+    /// Additional configuration that bootstrap needs to know only when running tests.
+    #[builder(default)]
+    test_config: TestConfig,
+}
+
+/// Builds have optional components, and their presence/absence can enable/disable a subset of
+/// tests. When testing the optimized artifacts, bootstrap needs to know about these enabled
+/// components to run the expected subset. This structure holds the known components where this
+/// matters: currently only whether the build to test is using debug assertions.
+///
+/// FIXME: ultimately, this is a temporary band-aid, and opt-dist should be more transparent to the
+/// CI config and bootstrap optional components: bootstrap has default values, combinations of flags
+/// that cascade into others, etc logic that we'd have to duplicate here otherwise. It's more
+/// sensible for opt-dist to never know about the config apart from the minimal set of paths
+/// required to configure stage0 tests.
+#[derive(Builder, Default, Clone, Debug)]
+pub struct TestConfig {
+    /// Whether the build under test is explicitly using `--enable-debug-assertions`.
+    /// Note that this flag can be implied from others, like `rust.debug`, and we do not handle any
+    /// of these subtleties and defaults here, as per the FIXME above.
+    pub enable_debug_assertions: bool,
 }
 
 impl Environment {
@@ -101,6 +122,21 @@ impl Environment {
     pub fn benchmark_cargo_config(&self) -> &[String] {
         &self.benchmark_cargo_config
     }
+
+    pub fn test_config(&self) -> &TestConfig {
+        &self.test_config
+    }
+}
+
+impl TestConfig {
+    /// Returns the test config matching the given `RUST_CONFIGURE_ARGS` for the known optional
+    /// components for tests. This is obviously extremely fragile and we'd rather opt-dist not
+    /// handle any optional components.
+    pub fn from_configure_args(configure_args: &str) -> TestConfig {
+        let enable_debug_assertions =
+            configure_args.split(" ").find(|part| *part == "--enable-debug-assertions").is_some();
+        TestConfig { enable_debug_assertions }
+    }
 }
 
 /// What is the extension of binary executables on this platform?