Rollup merge of #112300 - Zalathar:run-coverage, r=wesleywiser

Convert `run-make/coverage-reports` tests to use a custom compiletest mode

I was frustrated by the fact that most of the coverage tests are glued together with makefiles and shell scripts, so I tried my hand at converting most of them over to a newly-implemented `run-coverage` mode/suite in compiletest.

This ~~*mostly*~~ resolves #85009, ~~though I've left a small number of the existing tests as-is because they would require more work to fix/support~~.

---

I had time to go back and add support for the more troublesome tests that I had initially skipped over, so this PR now manages to completely get rid of `run-make/coverage-reports`.

---

The patches are arranged as follows:

- Declare the new mode/suite in bootstrap
- Small changes to compiletest that will be used by the new mode
- Implement the new mode in compiletest
- Migrate most of the tests over
- Add more code to bootstrap and compiletest to support the remaining tests
- Migrate the remaining tests (with some temporary hacks to avoid re-blessing them)
- Remove the temporary hacks and re-bless the migrated tests
- Remove the unused remnants of `run-make/coverage-reports`

2 files changed, 18 insertions, 4 deletions

diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 7c8e3536df5..a1d3453377a 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -686,6 +686,7 @@ impl<'a> Builder<'a> {
                 test::Tidy,
                 test::Ui,
                 test::RunPassValgrind,
+                test::RunCoverage,
                 test::MirOpt,
                 test::Codegen,
                 test::CodegenUnits,
@@ -694,6 +695,7 @@ impl<'a> Builder<'a> {
                 test::Debuginfo,
                 test::UiFullDeps,
                 test::Rustdoc,
+                test::RunCoverageRustdoc,
                 test::Pretty,
                 test::Crate,
                 test::CrateLibrustc,
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index ec447a1cd73..2c1f612e39f 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1319,6 +1319,13 @@ host_test!(RunMakeFullDeps {
 
 default_test!(Assembly { path: "tests/assembly", mode: "assembly", suite: "assembly" });
 
+host_test!(RunCoverage { path: "tests/run-coverage", mode: "run-coverage", suite: "run-coverage" });
+host_test!(RunCoverageRustdoc {
+    path: "tests/run-coverage-rustdoc",
+    mode: "run-coverage",
+    suite: "run-coverage-rustdoc"
+});
+
 // For the mir-opt suite we do not use macros, as we need custom behavior when blessing.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct MirOpt {
@@ -1503,6 +1510,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
             || (mode == "ui" && is_rustdoc)
             || mode == "js-doc-test"
             || mode == "rustdoc-json"
+            || suite == "run-coverage-rustdoc"
         {
             cmd.arg("--rustdoc-path").arg(builder.rustdoc(compiler));
         }
@@ -1516,7 +1524,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
                 .arg(builder.ensure(tool::JsonDocLint { compiler: json_compiler, target }));
         }
 
-        if mode == "run-make" {
+        if mode == "run-make" || mode == "run-coverage" {
             let rust_demangler = builder
                 .ensure(tool::RustDemangler {
                     compiler,
@@ -1703,17 +1711,21 @@ note: if you're sure you want to do this, please open an issue as to why. In the
                 add_link_lib_path(vec![llvm_libdir.trim().into()], &mut cmd);
             }
 
-            // Only pass correct values for these flags for the `run-make` suite as it
-            // requires that a C++ compiler was configured which isn't always the case.
-            if !builder.config.dry_run() && matches!(suite, "run-make" | "run-make-fulldeps") {
+            if !builder.config.dry_run()
+                && (matches!(suite, "run-make" | "run-make-fulldeps") || mode == "run-coverage")
+            {
                 // The llvm/bin directory contains many useful cross-platform
                 // tools. Pass the path to run-make tests so they can use them.
+                // (The run-coverage tests also need these tools to process
+                // coverage reports.)
                 let llvm_bin_path = llvm_config
                     .parent()
                     .expect("Expected llvm-config to be contained in directory");
                 assert!(llvm_bin_path.is_dir());
                 cmd.arg("--llvm-bin-dir").arg(llvm_bin_path);
+            }
 
+            if !builder.config.dry_run() && matches!(suite, "run-make" | "run-make-fulldeps") {
                 // If LLD is available, add it to the PATH
                 if builder.config.lld_enabled {
                     let lld_install_root =