Auto merge of #145384 - ywxt:parallel-tests, r=jieyouxu

Add more tests for the parallel rustc

At the moment, the parallel frontend test cases are severely lacking. Althought some reported issues have been resolved, they haven't been added into the tests.

This PR arranges the resolved ICE issues and adds tests for them.

Whether it is worthwhile to add a separate test suite for the paralel frontend still requires futher discussion. But we are trying coveraging issues being resolved through capability of the existing UI test suite.

Discussion: [Zulip](https://rust-lang.zulipchat.com/#narrow/channel/233931-t-compiler.2Fmajor-changes/topic/Proposal.20for.20a.20dedicated.20test.20suite.20for.20t.E2.80.A6.20compiler-team.23906)

Related issues:
- #120760
- #124423 fixed by #140358
- #127971 fxied by #140358
- #120601 fixed by #127311

cc `@jieyouxu`

Author: bors

src/doc/rustc-dev-guide/src/tests/directives.md

@@ -111,6 +111,7 @@ for more details.
 | `forbid-output`                   | A pattern which must not appear in stderr/`cfail` output                                                                 | `ui`, `incremental`                          | Regex pattern                                                                           |
 | `run-flags`                       | Flags passed to the test executable                                                                                      | `ui`                                         | Arbitrary flags                                                                         |
 | `known-bug`                       | No error annotation needed due to known bug                                                                              | `ui`, `crashes`, `incremental`               | Issue number `#123456`                                                                  |
+| `compare-output-by-lines`         | Compare the output by lines, rather than as a single string                                                              | All                                          | N/A                                                                                     |
 
 [^check_stdout]: presently <!-- date-check: Oct 2024 --> this has a weird quirk
     where the test binary's stdout and stderr gets concatenated and then

src/doc/rustc-dev-guide/src/tests/ui.md

@@ -95,6 +95,7 @@ will check for output files:
   [Normalization](#normalization)).
 - `dont-check-compiler-stderr` — Ignores stderr from the compiler.
 - `dont-check-compiler-stdout` — Ignores stdout from the compiler.
+- `compare-output-by-lines` — Some tests have non-deterministic orders of output, so we need to compare by lines.
 
 UI tests run with `-Zdeduplicate-diagnostics=no` flag which disables rustc's
 built-in diagnostic deduplication mechanism. This means you may see some

src/tools/compiletest/src/directives.rs

@@ -205,6 +205,8 @@ pub struct TestProps {
     pub dont_require_annotations: HashSet<ErrorKind>,
     /// Whether pretty printers should be disabled in gdb.
     pub disable_gdb_pretty_printers: bool,
+    /// Compare the output by lines, rather than as a single string.
+    pub compare_output_by_lines: bool,
 }
 
 mod directives {
@@ -254,6 +256,7 @@ mod directives {
     // This isn't a real directive, just one that is probably mistyped often
     pub const INCORRECT_COMPILER_FLAGS: &'static str = "compiler-flags";
     pub const DISABLE_GDB_PRETTY_PRINTERS: &'static str = "disable-gdb-pretty-printers";
+    pub const COMPARE_OUTPUT_BY_LINES: &'static str = "compare-output-by-lines";
 }
 
 impl TestProps {
@@ -310,6 +313,7 @@ impl TestProps {
             add_core_stubs: false,
             dont_require_annotations: Default::default(),
             disable_gdb_pretty_printers: false,
+            compare_output_by_lines: false,
         }
     }
 
@@ -664,6 +668,11 @@ impl TestProps {
                         DISABLE_GDB_PRETTY_PRINTERS,
                         &mut self.disable_gdb_pretty_printers,
                     );
+                    config.set_name_directive(
+                        ln,
+                        COMPARE_OUTPUT_BY_LINES,
+                        &mut self.compare_output_by_lines,
+                    );
                 },
             );
 

src/tools/compiletest/src/directives/directive_names.rs

@@ -17,6 +17,7 @@ pub(crate) const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "check-run-results",
     "check-stdout",
     "check-test-line-numbers-match",
+    "compare-output-by-lines",
     "compile-flags",
     "disable-gdb-pretty-printers",
     "doc-flags",

src/tools/compiletest/src/runtest.rs

@@ -2754,7 +2754,11 @@ impl<'test> TestCx<'test> {
         // Wrapper tools set by `runner` might provide extra output on failure,
         // for example a WebAssembly runtime might print the stack trace of an
         // `unreachable` instruction by default.
-        let compare_output_by_lines = self.config.runner.is_some();
+        //
+        // Also, some tests like `ui/parallel-rustc` have non-deterministic
+        // orders of output, so we need to compare by lines.
+        let compare_output_by_lines =
+            self.props.compare_output_by_lines || self.config.runner.is_some();
 
         let tmp;
         let (expected, actual): (&str, &str) = if compare_output_by_lines {

tests/ui/parallel-rustc/cache-after-waiting-issue-111528.rs

@@ -1,16 +1,18 @@
+// Test for #111528, the ice issue cause waiting on a query that panicked
+//
 //@ compile-flags: -Z threads=16
 //@ build-fail
+//@ compare-output-by-lines
 
-#![crate_type="rlib"]
+#![crate_type = "rlib"]
 #![allow(warnings)]
 
-#[export_name="fail"]
-pub fn a() {
-}
+#[export_name = "fail"]
+pub fn a() {}
 
-#[export_name="fail"]
+#[export_name = "fail"]
 pub fn b() {
-//~^ ERROR symbol `fail` is already defined
+    //~^ ERROR symbol `fail` is already defined
 }
 
 fn main() {}

tests/ui/parallel-rustc/cache-after-waiting-issue-111528.stderr

@@ -1,5 +1,5 @@
 error: symbol `fail` is already defined
-  --> $DIR/cache-after-waiting-issue-111528.rs:12:1
+  --> $DIR/cache-after-waiting-issue-111528.rs:14:1
    |
 LL | pub fn b() {
    | ^^^^^^^^^^

tests/ui/parallel-rustc/cycle_crash-issue-135870.rs

@@ -0,0 +1,8 @@
+// Test for #135870, which causes a deadlock bug
+//
+//@ compile-flags: -Z threads=2
+//@ compare-output-by-lines
+
+const FOO: usize = FOO; //~ ERROR cycle detected when simplifying constant for the type system `FOO`
+
+fn main() {}

tests/ui/parallel-rustc/cycle_crash.stderr renamed to tests/ui/parallel-rustc/cycle_crash-issue-135870.stderr

@@ -1,11 +1,11 @@
 error[E0391]: cycle detected when simplifying constant for the type system `FOO`
-  --> $DIR/cycle_crash.rs:3:1
+  --> $DIR/cycle_crash-issue-135870.rs:6:1
    |
 LL | const FOO: usize = FOO;
    | ^^^^^^^^^^^^^^^^
    |
 note: ...which requires const-evaluating + checking `FOO`...
-  --> $DIR/cycle_crash.rs:3:20
+  --> $DIR/cycle_crash-issue-135870.rs:6:20
    |
 LL | const FOO: usize = FOO;
    |                    ^^^