Rollup merge of #121233 - Zalathar:extra-directives, r=oli-obk

Move the extra directives for `Mode::CoverageRun` into `iter_header`

When these extra directives were ported over as part of #112300, it made sense to introduce `iter_header_extra` and pass them in as an extra argument.

But now that #120881 has added a `mode` parameter to `iter_header` for its own purposes, it's slightly simpler to move the coverage special-case code directly into `iter_header` as well. This lets us get rid of `iter_header_extra`.

src/tools/compiletest/src/header.rs

@@ -55,7 +55,7 @@ pub fn from_reader<R: Read>(config: &Config, testfile: &Path, rdr: R) -> Self {
             &mut poisoned,
             testfile,
             rdr,
-            &mut |_, _, ln, _| {
+            &mut |HeaderLine { directive: ln, .. }| {
                 config.push_name_value_directive(ln, directives::AUX_BUILD, &mut props.aux, |r| {
                     r.trim().to_string()
                 });
@@ -330,8 +330,8 @@ fn load_from(&mut self, testfile: &Path, cfg: Option<&str>, config: &Config) {
                 &mut poisoned,
                 testfile,
                 file,
-                &mut |revision, _, ln, _| {
+                &mut |HeaderLine { header_revision, directive: ln, .. }| {
-                    if revision.is_some() && revision != cfg {
+                    if header_revision.is_some() && header_revision != cfg {
                         return;
                     }
 
@@ -672,17 +672,6 @@ pub fn line_directive<'line>(
     }
 }
 
-fn iter_header<R: Read>(
-    mode: Mode,
-    suite: &str,
-    poisoned: &mut bool,
-    testfile: &Path,
-    rdr: R,
-    it: &mut dyn FnMut(Option<&str>, &str, &str, usize),
-) {
-    iter_header_extra(mode, suite, poisoned, testfile, rdr, &[], it)
-}
-
 /// This is generated by collecting directives from ui tests and then extracting their directive
 /// names. This is **not** an exhaustive list of all possible directives. Instead, this is a
 /// best-effort approximation for diagnostics.
@@ -801,23 +790,49 @@ fn iter_header<R: Read>(
     "unset-rustc-env",
 ];
 
-fn iter_header_extra(
+/// Arguments passed to the callback in [`iter_header`].
+struct HeaderLine<'ln> {
+    /// Contents of the square brackets preceding this header, if present.
+    header_revision: Option<&'ln str>,
+    /// Raw line from the test file, including comment prefix and any revision.
+    original_line: &'ln str,
+    /// Remainder of the directive line, after the initial comment prefix
+    /// (`//` or `//@` or `#`) and revision (if any) have been stripped.
+    directive: &'ln str,
+    line_number: usize,
+}
+
+fn iter_header(
     mode: Mode,
     suite: &str,
     poisoned: &mut bool,
     testfile: &Path,
     rdr: impl Read,
-    extra_directives: &[&str],
+    it: &mut dyn FnMut(HeaderLine<'_>),
-    it: &mut dyn FnMut(Option<&str>, &str, &str, usize),
 ) {
     if testfile.is_dir() {
         return;
     }
 
-    // Process any extra directives supplied by the caller (e.g. because they
+    // Coverage tests in coverage-run mode always have these extra directives,
-    // are implied by the test mode), with a dummy line number of 0.
+    // without needing to specify them manually in every test file.
+    // (Some of the comments below have been copied over from the old
+    // `tests/run-make/coverage-reports/Makefile`, which no longer exists.)
+    if mode == Mode::CoverageRun {
+        let extra_directives: &[&str] = &[
+            "needs-profiler-support",
+            // FIXME(mati865): MinGW GCC miscompiles compiler-rt profiling library but with Clang it works
+            // properly. Since we only have GCC on the CI ignore the test for now.
+            "ignore-windows-gnu",
+            // FIXME(pietroalbini): this test currently does not work on cross-compiled
+            // targets because remote-test is not capable of sending back the *.profraw
+            // files generated by the LLVM instrumentation.
+            "ignore-cross-compile",
+        ];
+        // Process the extra implied directives, with a dummy line number of 0.
         for directive in extra_directives {
-        it(None, directive, directive, 0);
+            it(HeaderLine { header_revision: None, original_line: "", directive, line_number: 0 });
+        }
     }
 
     let comment = if testfile.extension().is_some_and(|e| e == "rs") {
@@ -843,14 +858,14 @@ fn iter_header_extra(
         // Assume that any directives will be found before the first
         // module or function. This doesn't seem to be an optimization
         // with a warm page cache. Maybe with a cold one.
-        let orig_ln = &ln;
+        let original_line = &ln;
         let ln = ln.trim();
         if ln.starts_with("fn") || ln.starts_with("mod") {
             return;
 
         // First try to accept `ui_test` style comments
-        } else if let Some((lncfg, ln)) = line_directive(comment, ln) {
+        } else if let Some((header_revision, directive)) = line_directive(comment, ln) {
-            it(lncfg, orig_ln, ln, line_number);
+            it(HeaderLine { header_revision, original_line, directive, line_number });
         } else if mode == Mode::Ui && suite == "ui" && !REVISION_MAGIC_COMMENT_RE.is_match(ln) {
             let Some((_, rest)) = line_directive("//", ln) else {
                 continue;
@@ -1150,37 +1165,16 @@ pub fn make_test_description<R: Read>(
     let mut ignore_message = None;
     let mut should_fail = false;
 
-    let extra_directives: &[&str] = match config.mode {
-        // The coverage-run tests are treated as having these extra directives,
-        // without needing to specify them manually in every test file.
-        // (Some of the comments below have been copied over from
-        // `tests/run-make/coverage-reports/Makefile`, which no longer exists.)
-        Mode::CoverageRun => {
-            &[
-                "needs-profiler-support",
-                // FIXME(mati865): MinGW GCC miscompiles compiler-rt profiling library but with Clang it works
-                // properly. Since we only have GCC on the CI ignore the test for now.
-                "ignore-windows-gnu",
-                // FIXME(pietroalbini): this test currently does not work on cross-compiled
-                // targets because remote-test is not capable of sending back the *.profraw
-                // files generated by the LLVM instrumentation.
-                "ignore-cross-compile",
-            ]
-        }
-        _ => &[],
-    };
-
     let mut local_poisoned = false;
 
-    iter_header_extra(
+    iter_header(
         config.mode,
         &config.suite,
         &mut local_poisoned,
         path,
         src,
-        extra_directives,
+        &mut |HeaderLine { header_revision, original_line, directive: ln, line_number }| {
-        &mut |revision, og_ln, ln, line_number| {
+            if header_revision.is_some() && header_revision != cfg {
-            if revision.is_some() && revision != cfg {
                 return;
             }
 
@@ -1204,7 +1198,7 @@ macro_rules! decision {
                 };
             }
 
-            if let Some((_, post)) = og_ln.trim_start().split_once("//") {
+            if let Some((_, post)) = original_line.trim_start().split_once("//") {
                 let post = post.trim_start();
                 if post.starts_with("ignore-tidy")
                     && config.mode == Mode::Ui