Auto merge of #147372 - jieyouxu:rust-analyzer-main-tests, r=Kobzol

Run main rust-analyzer tests in rust-lang/rust CI

Part of #147370.
MCP: rust-lang/compiler-team#923

This PR prepares `rust-analyzer` crates with `in-rust-tree` cargo featues where needed, and and updates bootstrap to run the main `rust-analyzer` tests in rust-lang/rust CI, not just the `proc-macro-srv` crate tests.

This supersedes the earlier attempt at #136779. I was honestly expecting more failures in this PR, but looking back at the previous attempt, that makes sense because we no longer run `i686-mingw` (32-bit windows-gnu) which had a _bunch_ of these failures. In the earlier attempt I also disabled the `i686-mingw`-related failures for `i686-msvc` since I didn't feel like digging into 32-bit msvc at the time. Try results from this PR shows that it's most likely limited to 32-bit windows-gnu specifically.

### `rust-analyzer` test remarks

- I actually had to _remove_ the `CARGO_WORKSPACE_DIR` `expect-test`-hack in order for `expect-test` to be able to find the test expectation HTML files (for `syntax_highlighting` tests in `ide`). When I added the hack, ironically, it made `expect-test` unable to find the expectation files. I think this was because previously the path was of the `proc-macro-srv` crate specifically, now we point to the root r-a workspace?
- The `cfg`-related differences on `aarch64-apple-darwin` might've been fixed? I can't tell, but we don't seem to be observing the differences now.
- I'm not sure why `config::{generate_config_documentation, generate_package_json_config}` no longer fails. Perhaps they were fixed to no longer try to write to source directory?

### Review remarks

- Commit 1 updates r-a crates that are involved in tests needing artifacts from `rustc_private` compiler crates to use the `in-rust-tree` cargo feature. I briefly tried to use a plain `--cfg=in_rust_tree`, but quickly realized it was very hacky, and needed invasive bootstrap changes. The cargo feature approach seems most "natural"/well-supported to both bootstrap and cargo.
- Commit 2 updates bootstrap to not only run the `proc-macro-srv` tests, but the whole r-a tests.
- Commit 3 restricts r-a main tests to non-32-bit targets we test in CI, since (1) r-a repo does not run tests against 32-bit platforms, and (2) there are some target pointer width sensitive hash differences causing tests to fail. Notably, this means that we also no longer run r-a `proc-macro-srv` tests against 32-bit targets, but we don't expect that crate to be have target pointer width differences. Discussed this in [#t-compiler/rust-analyzer > 32-bit tests?](https://rust-lang.zulipchat.com/#narrow/channel/185405-t-compiler.2Frust-analyzer/topic/32-bit.20tests.3F/with/563145736).

---

// try-job: aarch64-gnu
// try-job: aarch64-apple
// try-job: x86_64-mingw-1
// try-job: i686-msvc-1
// try-job: x86_64-msvc-1
// try-job: aarch64-msvc-1

Author: bors

src/bootstrap/src/core/build_steps/test.rs

@@ -465,35 +465,73 @@ impl Step for RustAnalyzer {
 
     /// Runs `cargo test` for rust-analyzer
     fn run(self, builder: &Builder<'_>) {
-        let host = self.compilers.target();
+        let build_compiler = self.compilers.build_compiler();
+        let target = self.compilers.target();
+
+        // NOTE: rust-analyzer repo currently (as of 2025-12-11) does not run tests against 32-bit
+        // targets, so we also don't run them in rust-lang/rust CI (because that will just mean that
+        // subtree syncs will keep getting 32-bit-specific failures that are not observed in
+        // rust-analyzer repo CI).
+        //
+        // Some 32-bit specific failures include e.g. target pointer width specific hashes.
+
+        // FIXME: eventually, we should probably reduce the amount of target tuple substring
+        // matching in bootstrap.
+        if target.starts_with("i686") {
+            return;
+        }
 
-        let workspace_path = "src/tools/rust-analyzer";
-        // until the whole RA test suite runs on `i686`, we only run
-        // `proc-macro-srv` tests
-        let crate_path = "src/tools/rust-analyzer/crates/proc-macro-srv";
         let mut cargo = tool::prepare_tool_cargo(
             builder,
-            self.compilers.build_compiler(),
+            build_compiler,
             Mode::ToolRustcPrivate,
-            host,
+            target,
             Kind::Test,
-            crate_path,
+            "src/tools/rust-analyzer",
             SourceType::InTree,
             &["in-rust-tree".to_owned()],
         );
         cargo.allow_features(tool::RustAnalyzer::ALLOW_FEATURES);
 
-        let dir = builder.src.join(workspace_path);
-        // needed by rust-analyzer to find its own text fixtures, cf.
-        // https://github.com/rust-analyzer/expect-test/issues/33
-        cargo.env("CARGO_WORKSPACE_DIR", &dir);
+        // N.B. it turns out _setting_ `CARGO_WORKSPACE_DIR` actually somehow breaks `expect-test`,
+        // even though previously we actually needed to set that hack to allow `expect-test` to
+        // correctly discover the r-a workspace instead of the outer r-l/r workspace.
 
-        // RA's test suite tries to write to the source directory, that can't
-        // work in Rust CI
+        // FIXME: RA's test suite tries to write to the source directory, that can't work in Rust CI
+        // without properly wiring up the writable test dir.
         cargo.env("SKIP_SLOW_TESTS", "1");
 
+        // NOTE: we need to skip `src/tools/rust-analyzer/xtask` as they seem to exercise rustup /
+        // stable rustfmt.
+        //
+        // NOTE: you can only skip a specific workspace package via `--exclude=...` if you *also*
+        // specify `--workspace`.
+        cargo.arg("--workspace");
+        cargo.arg("--exclude=xtask");
+
+        let mut skip_tests = vec![];
+
+        // NOTE: the following test skips is a bit cheeky in that it assumes there are no
+        // identically named tests across different r-a packages, where we want to run the
+        // identically named test in one package but not another. If we want to support that use
+        // case, we'd have to run the r-a tests in two batches (with one excluding the package that
+        // we *don't* want to run the test for, and the other batch including).
+
+        // Across all platforms.
+        skip_tests.extend_from_slice(&[
+            // FIXME: this test wants to find a `rustc`. We need to provide it with a path to staged
+            // in-tree `rustc`, but setting `RUSTC` env var requires some reworking of bootstrap.
+            "tests::smoke_test_real_sysroot_cargo",
+            // NOTE: part of `smol-str` test suite; this tries to access a stable rustfmt from the
+            // environment, which is not something we want to do.
+            "check_code_formatting",
+        ]);
+
+        let skip_tests = skip_tests.iter().map(|name| format!("--skip={name}")).collect::<Vec<_>>();
+        let skip_tests = skip_tests.iter().map(|s| s.as_str()).collect::<Vec<_>>();
+
         cargo.add_rustc_lib_path(builder);
-        run_cargo_test(cargo, &[], &[], "rust-analyzer", host, builder);
+        run_cargo_test(cargo, skip_tests.as_slice(), &[], "rust-analyzer", target, builder);
     }
 
     fn metadata(&self) -> Option<StepMetadata> {

src/tools/rust-analyzer/crates/base-db/Cargo.toml

@@ -31,5 +31,9 @@ vfs.workspace = true
 span.workspace = true
 intern.workspace = true
 
+[features]
+default = []
+in-rust-tree = []
+
 [lints]
 workspace = true

src/tools/rust-analyzer/crates/base-db/src/lib.rs

@@ -1,5 +1,10 @@
 //! base_db defines basic database traits. The concrete DB is defined by ide.
 
+#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
+
+#[cfg(feature = "in-rust-tree")]
+extern crate rustc_driver as _;
+
 pub use salsa;
 pub use salsa_macros;
 

src/tools/rust-analyzer/crates/cfg/Cargo.toml

@@ -33,5 +33,9 @@ syntax.workspace = true
 # tt is needed for testing
 cfg = { path = ".", default-features = false, features = ["tt"] }
 
+[features]
+default = []
+in-rust-tree = []
+
 [lints]
 workspace = true

src/tools/rust-analyzer/crates/cfg/src/lib.rs

@@ -1,5 +1,10 @@
 //! cfg defines conditional compiling options, `cfg` attribute parser and evaluator
 
+#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
+
+#[cfg(feature = "in-rust-tree")]
+extern crate rustc_driver as _;
+
 mod cfg_expr;
 mod dnf;
 #[cfg(test)]

src/tools/rust-analyzer/crates/ide-completion/Cargo.toml

@@ -37,5 +37,9 @@ expect-test = "1.5.1"
 test-utils.workspace = true
 test-fixture.workspace = true
 
+[features]
+default = []
+in-rust-tree = []
+
 [lints]
 workspace = true

src/tools/rust-analyzer/crates/ide-completion/src/lib.rs

@@ -3,6 +3,11 @@
 // It's useful to refer to code that is private in doc comments.
 #![allow(rustdoc::private_intra_doc_links)]
 
+#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
+
+#[cfg(feature = "in-rust-tree")]
+extern crate rustc_driver as _;
+
 mod completions;
 mod config;
 mod context;

src/tools/rust-analyzer/crates/ide-db/Cargo.toml

@@ -52,5 +52,9 @@ line-index.workspace = true
 [dev-dependencies]
 expect-test = "1.5.1"
 
+[features]
+default = []
+in-rust-tree = []
+
 [lints]
 workspace = true

src/tools/rust-analyzer/crates/ide-db/src/lib.rs

@@ -2,6 +2,11 @@
 //!
 //! It is mainly a `HirDatabase` for semantic analysis, plus a `SymbolsDatabase`, for fuzzy search.
 
+#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
+
+#[cfg(feature = "in-rust-tree")]
+extern crate rustc_driver as _;
+
 extern crate self as ide_db;
 
 mod apply_change;

src/tools/rust-analyzer/crates/ide-diagnostics/Cargo.toml

@@ -34,5 +34,9 @@ expect-test = "1.5.1"
 test-utils.workspace = true
 test-fixture.workspace = true
 
+[features]
+default = []
+in-rust-tree = []
+
 [lints]
 workspace = true