Auto merge of #121370 - jieyouxu:migrate-compiletest-directives, r=oli-obk

Migrate compiletest to use `ui_test`-style `//@` directives

## Preface

There's an on-going effort to rewrite parts of or the entirety of compiletest
(<https://github.com/rust-lang/compiler-team/issues/536>). A step towards this involve migrating
compiletest tests to use the [`ui_test`](https://github.com/oli-obk/ui_test) framework, which
involves changing compiletest directives in `// <directive-name>` style to `ui_test`
`//@ <directive-name>` style (https://github.com/rust-lang/compiler-team/issues/512).

This PR aims to implement the directive-style change from `//` to `//`@`` for the remaining
non-"ui" test suite tests.

## Key Changes

1. All `tests/` tests now use `//`@`` directives.
2. Compiletest only accepts `//`@`` and issues an error if an old-style directive is detected.
3. `// ignore-tidy` and `// ignore-tidy-*` are considered tidy directives and are ignored by
   compiletest header parsing.

## Diff Generation

The diff is generated by:

- Collecting directives from `tests/` via hijacking compiletest to emit successfully parsed
  directive lines.
- Using a migration tool
  (<https://github.com/jieyouxu/compiletest-ui_test-header-migration/tree/master>) to replace
  `//` directives in compiletest tests with `//`@`.`

### Reproduction Steps

0. Delete the temporary file `$RUSTC_REPO_PATH/build/<target_triple>/test/__directive_lines.txt`,
   if the collection script was previously ran.
1. Use the <https://github.com/jieyouxu/rust/tree/collect-test-directives> collect-test-directives
   script, which outputs a temporary file recording headers occuring in each compiletest test.
   - You need to checkout this branch: `git checkout collect-test-directives`.
   - This needs to be rebased on latest master to ensure up-to-date test directives can be collected.
   - You need to run `./x test` on each of the `test/*` subfolders once:

        ```bash
        ./x test tests/assembly/ --stage 1 --force-rerun
        ./x test tests/codegen/ --stage 1 --force-rerun
        ./x test tests/codegen-units/ --stage 1 --force-rerun
        ./x test tests/coverage/ --stage 1 --force-rerun
        ./x test tests/coverage-run-rustdoc/ --stage 1 --force-rerun
        ./x test tests/debuginfo/ --stage 1 --force-rerun
        ./x test tests/incremental/ --stage 1 --force-rerun
        ./x test tests/mir-opt/ --stage 1 --force-rerun
        ./x test tests/pretty/ --stage 1 --force-rerun
        ./x test tests/run-make/ --stage 1 --force-rerun
        ./x test tests/run-make-fulldeps/ --stage 1 --force-rerun
        ./x test tests/run-pass-valgrind/ --stage 1 --force-rerun
        ./x test tests/rustdoc/ --stage 1 --force-rerun
        TARGET=<target-triple> ./x test tests/rustdoc-gui/ --stage 1 --force-rerun
        ./x test tests/rustdoc-js/ --stage 1 --force-rerun
        ./x test tests/rustdoc-js-std/ --stage 1 --force-rerun
        ./x test tests/rustdoc-json/ --stage 1 --force-rerun
        ./x test tests/rustdoc-ui/ --stage 1 --force-rerun
        ./x test tests/ui/ --stage 1 --force-rerun
        ./x test tests/ui-fulldeps/ --stage 1 --force-rerun
        ```

2. Checkout the `migrate-compiletest-directives` branch.
3. Run the migration tool <https://github.com/jieyouxu/compiletest-ui_test-header-migration>.
4. Check that the migration at least does not cause test failures if you change compiletest to
   accept `//`@`` directives only. This is also required if the test outputs somehow need to be
   blessed.
   - `RUSTC_TEST_FAIL_FAST=1 ./x test tests/<secondary-directory>  --stage 1 --bless`
5. Confirm that there is no difference after running the migration tool when you are on the
   `migrate-compiletest-directives` branch.

## Follow Up Work

- [ ] Adjust rustc-dev-guide docs for compiletest directives (this time for all the other suites and modes). <https://github.com/rust-lang/rustc-dev-guide/pull/1895>.

11 files changed, 17 insertions, 17 deletions

diff --git a/tests/codegen/enum/enum-bounds-check-derived-idx.rs b/tests/codegen/enum/enum-bounds-check-derived-idx.rs
index aa66c2ed08e..15280cb2e6c 100644
--- a/tests/codegen/enum/enum-bounds-check-derived-idx.rs
+++ b/tests/codegen/enum/enum-bounds-check-derived-idx.rs
@@ -1,6 +1,6 @@
 // This test checks an optimization that is not guaranteed to work. This test case should not block
 // a future LLVM update.
-// compile-flags: -O
+//@ compile-flags: -O
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen/enum/enum-bounds-check-issue-13926.rs b/tests/codegen/enum/enum-bounds-check-issue-13926.rs
index b26945bc549..b60ff38ce39 100644
--- a/tests/codegen/enum/enum-bounds-check-issue-13926.rs
+++ b/tests/codegen/enum/enum-bounds-check-issue-13926.rs
@@ -1,6 +1,6 @@
 // This test checks an optimization that is not guaranteed to work. This test case should not block
 // a future LLVM update.
-// compile-flags: -O
+//@ compile-flags: -O
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen/enum/enum-bounds-check-issue-82871.rs b/tests/codegen/enum/enum-bounds-check-issue-82871.rs
index 32fdc4a5f4f..3b8a146838a 100644
--- a/tests/codegen/enum/enum-bounds-check-issue-82871.rs
+++ b/tests/codegen/enum/enum-bounds-check-issue-82871.rs
@@ -1,4 +1,4 @@
-// compile-flags: -C opt-level=0
+//@ compile-flags: -C opt-level=0
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen/enum/enum-bounds-check.rs b/tests/codegen/enum/enum-bounds-check.rs
index 17322d5911b..a1b32ec9295 100644
--- a/tests/codegen/enum/enum-bounds-check.rs
+++ b/tests/codegen/enum/enum-bounds-check.rs
@@ -1,4 +1,4 @@
-// compile-flags: -O
+//@ compile-flags: -O
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen/enum/enum-debug-clike.rs b/tests/codegen/enum/enum-debug-clike.rs
index 1e369a2c4e6..205c57d1456 100644
--- a/tests/codegen/enum/enum-debug-clike.rs
+++ b/tests/codegen/enum/enum-debug-clike.rs
@@ -2,9 +2,9 @@
 // This is ignored for the fallback mode on MSVC due to problems with PDB.
 
 //
-// ignore-msvc
+//@ ignore-msvc
 
-// compile-flags: -g -C no-prepopulate-passes
+//@ compile-flags: -g -C no-prepopulate-passes
 
 // CHECK-LABEL: @main
 // CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_enumeration_type,{{.*}}name: "E",{{.*}}flags: DIFlagEnumClass,{{.*}}
diff --git a/tests/codegen/enum/enum-debug-niche-2.rs b/tests/codegen/enum/enum-debug-niche-2.rs
index 4b607d50574..4315741e0bd 100644
--- a/tests/codegen/enum/enum-debug-niche-2.rs
+++ b/tests/codegen/enum/enum-debug-niche-2.rs
@@ -2,9 +2,9 @@
 // This is ignored for the fallback mode on MSVC due to problems with PDB.
 
 //
-// ignore-msvc
+//@ ignore-msvc
 
-// compile-flags: -g -C no-prepopulate-passes
+//@ compile-flags: -g -C no-prepopulate-passes
 
 // CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_variant_part,{{.*}}size: 32,{{.*}}
 // CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "Placeholder",{{.*}}extraData: i128 4294967295{{[,)].*}}
diff --git a/tests/codegen/enum/enum-debug-niche.rs b/tests/codegen/enum/enum-debug-niche.rs
index b718a6854dd..fc6a73e8472 100644
--- a/tests/codegen/enum/enum-debug-niche.rs
+++ b/tests/codegen/enum/enum-debug-niche.rs
@@ -1,9 +1,9 @@
 // This tests that optimized enum debug info accurately reflects the enum layout.
 // This is ignored for the fallback mode on MSVC due to problems with PDB.
 
-// ignore-msvc
+//@ ignore-msvc
 
-// compile-flags: -g -C no-prepopulate-passes
+//@ compile-flags: -g -C no-prepopulate-passes
 
 // CHECK-LABEL: @main
 // CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_variant_part,{{.*}}discriminator:{{.*}}
diff --git a/tests/codegen/enum/enum-debug-tagged.rs b/tests/codegen/enum/enum-debug-tagged.rs
index 095c49ac3ac..87a6ccae291 100644
--- a/tests/codegen/enum/enum-debug-tagged.rs
+++ b/tests/codegen/enum/enum-debug-tagged.rs
@@ -1,9 +1,9 @@
 // This tests that debug info for tagged (ordinary) enums is properly emitted.
 // This is ignored for the fallback mode on MSVC due to problems with PDB.
 
-// ignore-msvc
+//@ ignore-msvc
 
-// compile-flags: -g -C no-prepopulate-passes
+//@ compile-flags: -g -C no-prepopulate-passes
 
 // CHECK-LABEL: @main
 // CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "E",{{.*}}
diff --git a/tests/codegen/enum/enum-discriminant-value.rs b/tests/codegen/enum/enum-discriminant-value.rs
index cc14c212002..d6b0c6d6c10 100644
--- a/tests/codegen/enum/enum-discriminant-value.rs
+++ b/tests/codegen/enum/enum-discriminant-value.rs
@@ -1,6 +1,6 @@
 // Verify that DIEnumerator uses isUnsigned flag when appropriate.
 //
-// compile-flags: -g -C no-prepopulate-passes
+//@ compile-flags: -g -C no-prepopulate-passes
 
 #[repr(i64)]
 pub enum I64 {
diff --git a/tests/codegen/enum/enum-match.rs b/tests/codegen/enum/enum-match.rs
index 5548cd25147..2e6dad8791b 100644
--- a/tests/codegen/enum/enum-match.rs
+++ b/tests/codegen/enum/enum-match.rs
@@ -1,5 +1,5 @@
-// compile-flags: -Copt-level=1
-// only-x86_64
+//@ compile-flags: -Copt-level=1
+//@ only-x86_64
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen/enum/enum-u128.rs b/tests/codegen/enum/enum-u128.rs
index f50d360ac9f..94e80e34068 100644
--- a/tests/codegen/enum/enum-u128.rs
+++ b/tests/codegen/enum/enum-u128.rs
@@ -2,9 +2,9 @@
 // This is ignored for the fallback mode on MSVC due to problems with PDB.
 
 //
-// ignore-msvc
+//@ ignore-msvc
 
-// compile-flags: -g -C no-prepopulate-passes
+//@ compile-flags: -g -C no-prepopulate-passes
 
 // CHECK-LABEL: @main
 // CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_enumeration_type,{{.*}}name: "Foo",{{.*}}flags: DIFlagEnumClass,{{.*}}