diff --git a/src/tools/compiletest/src/command-list.rs b/src/tools/compiletest/src/command-list.rs
index 288f90ea12399..0706f3bee05c1 100644
--- a/src/tools/compiletest/src/command-list.rs
+++ b/src/tools/compiletest/src/command-list.rs
@@ -18,6 +18,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "check-test-line-numbers-match",
     "compare-output-lines-by-subset",
     "compile-flags",
+    "doc-flags",
     "dont-check-compiler-stderr",
     "dont-check-compiler-stdout",
     "dont-check-failure-status",
@@ -226,6 +227,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "should-ice",
     "stderr-per-bitwidth",
     "test-mir-pass",
+    "unique-doc-out-dir",
     "unset-exec-env",
     "unset-rustc-env",
     // Used by the tidy check `unknown_revision`.
diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index cde3e3295c631..1fc24301c85e6 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -95,6 +95,8 @@ pub struct TestProps {
     pub compile_flags: Vec<String>,
     // Extra flags to pass when the compiled code is run (such as --bench)
     pub run_flags: Vec<String>,
+    /// Extra flags to pass to rustdoc but not the compiler.
+    pub doc_flags: Vec<String>,
     // If present, the name of a file that this test should match when
     // pretty-printed
     pub pp_exact: Option<PathBuf>,
@@ -122,6 +124,9 @@ pub struct TestProps {
     pub unset_exec_env: Vec<String>,
     // Build documentation for all specified aux-builds as well
     pub build_aux_docs: bool,
+    /// Build the documentation for each crate in a unique output directory.
+    /// Uses <root output directory>/docs/<test name>/doc
+    pub unique_doc_out_dir: bool,
     // Flag to force a crate to be built with the host architecture
     pub force_host: bool,
     // Check stdout for error-pattern output as well as stderr
@@ -220,8 +225,10 @@ mod directives {
     pub const REGEX_ERROR_PATTERN: &'static str = "regex-error-pattern";
     pub const COMPILE_FLAGS: &'static str = "compile-flags";
     pub const RUN_FLAGS: &'static str = "run-flags";
+    pub const DOC_FLAGS: &'static str = "doc-flags";
     pub const SHOULD_ICE: &'static str = "should-ice";
     pub const BUILD_AUX_DOCS: &'static str = "build-aux-docs";
+    pub const UNIQUE_DOC_OUT_DIR: &'static str = "unique-doc-out-dir";
     pub const FORCE_HOST: &'static str = "force-host";
     pub const CHECK_STDOUT: &'static str = "check-stdout";
     pub const CHECK_RUN_RESULTS: &'static str = "check-run-results";
@@ -267,6 +274,7 @@ impl TestProps {
             regex_error_patterns: vec![],
             compile_flags: vec![],
             run_flags: vec![],
+            doc_flags: vec![],
             pp_exact: None,
             aux_builds: vec![],
             aux_bins: vec![],
@@ -281,6 +289,7 @@ impl TestProps {
             exec_env: vec![],
             unset_exec_env: vec![],
             build_aux_docs: false,
+            unique_doc_out_dir: false,
             force_host: false,
             check_stdout: false,
             check_run_results: false,
@@ -378,6 +387,8 @@ impl TestProps {
                         |r| r,
                     );
 
+                    config.push_name_value_directive(ln, DOC_FLAGS, &mut self.doc_flags, |r| r);
+
                     fn split_flags(flags: &str) -> Vec<String> {
                         // Individual flags can be single-quoted to preserve spaces; see
                         // <https://github.com/rust-lang/rust/pull/115948/commits/957c5db6>.
@@ -415,6 +426,8 @@ impl TestProps {
 
                     config.set_name_directive(ln, SHOULD_ICE, &mut self.should_ice);
                     config.set_name_directive(ln, BUILD_AUX_DOCS, &mut self.build_aux_docs);
+                    config.set_name_directive(ln, UNIQUE_DOC_OUT_DIR, &mut self.unique_doc_out_dir);
+
                     config.set_name_directive(ln, FORCE_HOST, &mut self.force_host);
                     config.set_name_directive(ln, CHECK_STDOUT, &mut self.check_stdout);
                     config.set_name_directive(ln, CHECK_RUN_RESULTS, &mut self.check_run_results);
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 1f15605d8beed..b1b6d6fc8eb18 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -1,5 +1,6 @@
 // ignore-tidy-filelength
 
+use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::ffi::{OsStr, OsString};
 use std::fs::{self, create_dir_all, File, OpenOptions};
@@ -723,7 +724,7 @@ impl<'test> TestCx<'test> {
         self.maybe_add_external_args(&mut rustc, &self.config.target_rustcflags);
         rustc.args(&self.props.compile_flags);
 
-        self.compose_and_run_compiler(rustc, Some(src))
+        self.compose_and_run_compiler(rustc, Some(src), self.testpaths)
     }
 
     fn run_debuginfo_test(&self) {
@@ -1579,13 +1580,15 @@ impl<'test> TestCx<'test> {
             passes,
         );
 
-        self.compose_and_run_compiler(rustc, None)
+        self.compose_and_run_compiler(rustc, None, self.testpaths)
     }
 
-    fn document(&self, out_dir: &Path) -> ProcRes {
+    /// `root_out_dir` and `root_testpaths` refer to the parameters of the actual test being run.
+    /// Auxiliaries, no matter how deep, have the same root_out_dir and root_testpaths.
+    fn document(&self, root_out_dir: &Path, root_testpaths: &TestPaths) -> ProcRes {
         if self.props.build_aux_docs {
             for rel_ab in &self.props.aux_builds {
-                let aux_testpaths = self.compute_aux_test_paths(&self.testpaths, rel_ab);
+                let aux_testpaths = self.compute_aux_test_paths(root_testpaths, rel_ab);
                 let aux_props =
                     self.props.from_aux_file(&aux_testpaths.file, self.revision, self.config);
                 let aux_cx = TestCx {
@@ -1596,7 +1599,9 @@ impl<'test> TestCx<'test> {
                 };
                 // Create the directory for the stdout/stderr files.
                 create_dir_all(aux_cx.output_base_dir()).unwrap();
-                let auxres = aux_cx.document(out_dir);
+                // use root_testpaths here, because aux-builds should have the
+                // same --out-dir and auxiliary directory.
+                let auxres = aux_cx.document(&root_out_dir, root_testpaths);
                 if !auxres.status.success() {
                     return auxres;
                 }
@@ -1606,21 +1611,40 @@ impl<'test> TestCx<'test> {
         let aux_dir = self.aux_output_dir_name();
 
         let rustdoc_path = self.config.rustdoc_path.as_ref().expect("--rustdoc-path not passed");
-        let mut rustdoc = Command::new(rustdoc_path);
 
+        // actual --out-dir given to the auxiliary or test, as opposed to the root out dir for the entire
+        // test
+        let out_dir: Cow<'_, Path> = if self.props.unique_doc_out_dir {
+            let file_name = self.testpaths.file.file_stem().expect("file name should not be empty");
+            let out_dir = PathBuf::from_iter([
+                root_out_dir,
+                Path::new("docs"),
+                Path::new(file_name),
+                Path::new("doc"),
+            ]);
+            create_dir_all(&out_dir).unwrap();
+            Cow::Owned(out_dir)
+        } else {
+            Cow::Borrowed(root_out_dir)
+        };
+
+        let mut rustdoc = Command::new(rustdoc_path);
+        let current_dir = output_base_dir(self.config, root_testpaths, self.safe_revision());
+        rustdoc.current_dir(current_dir);
         rustdoc
             .arg("-L")
             .arg(self.config.run_lib_path.to_str().unwrap())
             .arg("-L")
             .arg(aux_dir)
             .arg("-o")
-            .arg(out_dir)
+            .arg(out_dir.as_ref())
             .arg("--deny")
             .arg("warnings")
             .arg(&self.testpaths.file)
             .arg("-A")
             .arg("internal_features")
-            .args(&self.props.compile_flags);
+            .args(&self.props.compile_flags)
+            .args(&self.props.doc_flags);
 
         if self.config.mode == RustdocJson {
             rustdoc.arg("--output-format").arg("json").arg("-Zunstable-options");
@@ -1630,7 +1654,7 @@ impl<'test> TestCx<'test> {
             rustdoc.arg(format!("-Clinker={}", linker));
         }
 
-        self.compose_and_run_compiler(rustdoc, None)
+        self.compose_and_run_compiler(rustdoc, None, root_testpaths)
     }
 
     fn exec_compiled_test(&self) -> ProcRes {
@@ -1828,9 +1852,16 @@ impl<'test> TestCx<'test> {
         }
     }
 
-    fn compose_and_run_compiler(&self, mut rustc: Command, input: Option<String>) -> ProcRes {
+    /// `root_testpaths` refers to the path of the original test.
+    /// the auxiliary and the test with an aux-build have the same `root_testpaths`.
+    fn compose_and_run_compiler(
+        &self,
+        mut rustc: Command,
+        input: Option<String>,
+        root_testpaths: &TestPaths,
+    ) -> ProcRes {
         let aux_dir = self.aux_output_dir();
-        self.build_all_auxiliary(&self.testpaths, &aux_dir, &mut rustc);
+        self.build_all_auxiliary(root_testpaths, &aux_dir, &mut rustc);
 
         rustc.envs(self.props.rustc_env.clone());
         self.props.unset_rustc_env.iter().fold(&mut rustc, Command::env_remove);
@@ -2545,7 +2576,7 @@ impl<'test> TestCx<'test> {
             Vec::new(),
         );
 
-        let proc_res = self.compose_and_run_compiler(rustc, None);
+        let proc_res = self.compose_and_run_compiler(rustc, None, self.testpaths);
         let output_path = self.get_filecheck_file("ll");
         (proc_res, output_path)
     }
@@ -2581,7 +2612,7 @@ impl<'test> TestCx<'test> {
             Vec::new(),
         );
 
-        let proc_res = self.compose_and_run_compiler(rustc, None);
+        let proc_res = self.compose_and_run_compiler(rustc, None, self.testpaths);
         let output_path = self.get_filecheck_file("s");
         (proc_res, output_path)
     }
@@ -2664,7 +2695,7 @@ impl<'test> TestCx<'test> {
         let out_dir = self.output_base_dir();
         remove_and_create_dir_all(&out_dir);
 
-        let proc_res = self.document(&out_dir);
+        let proc_res = self.document(&out_dir, &self.testpaths);
         if !proc_res.status.success() {
             self.fatal_proc_rec("rustdoc failed!", &proc_res);
         }
@@ -2723,7 +2754,7 @@ impl<'test> TestCx<'test> {
         let aux_dir = new_rustdoc.aux_output_dir();
         new_rustdoc.build_all_auxiliary(&new_rustdoc.testpaths, &aux_dir, &mut rustc);
 
-        let proc_res = new_rustdoc.document(&compare_dir);
+        let proc_res = new_rustdoc.document(&compare_dir, &new_rustdoc.testpaths);
         if !proc_res.status.success() {
             eprintln!("failed to run nightly rustdoc");
             return;
@@ -2847,7 +2878,7 @@ impl<'test> TestCx<'test> {
         let out_dir = self.output_base_dir();
         remove_and_create_dir_all(&out_dir);
 
-        let proc_res = self.document(&out_dir);
+        let proc_res = self.document(&out_dir, &self.testpaths);
         if !proc_res.status.success() {
             self.fatal_proc_rec("rustdoc failed!", &proc_res);
         }
@@ -2923,31 +2954,24 @@ impl<'test> TestCx<'test> {
     fn check_rustdoc_test_option(&self, res: ProcRes) {
         let mut other_files = Vec::new();
         let mut files: HashMap<String, Vec<usize>> = HashMap::new();
-        let cwd = env::current_dir().unwrap();
-        files.insert(
-            self.testpaths
-                .file
-                .strip_prefix(&cwd)
-                .unwrap_or(&self.testpaths.file)
-                .to_str()
-                .unwrap()
-                .replace('\\', "/"),
-            self.get_lines(&self.testpaths.file, Some(&mut other_files)),
-        );
+        let normalized = fs::canonicalize(&self.testpaths.file).expect("failed to canonicalize");
+        let normalized = normalized.to_str().unwrap().replace('\\', "/");
+        files.insert(normalized, self.get_lines(&self.testpaths.file, Some(&mut other_files)));
         for other_file in other_files {
             let mut path = self.testpaths.file.clone();
             path.set_file_name(&format!("{}.rs", other_file));
-            files.insert(
-                path.strip_prefix(&cwd).unwrap_or(&path).to_str().unwrap().replace('\\', "/"),
-                self.get_lines(&path, None),
-            );
+            let path = fs::canonicalize(path).expect("failed to canonicalize");
+            let normalized = path.to_str().unwrap().replace('\\', "/");
+            files.insert(normalized, self.get_lines(&path, None));
         }
 
         let mut tested = 0;
         for _ in res.stdout.split('\n').filter(|s| s.starts_with("test ")).inspect(|s| {
             if let Some((left, right)) = s.split_once(" - ") {
                 let path = left.rsplit("test ").next().unwrap();
-                if let Some(ref mut v) = files.get_mut(&path.replace('\\', "/")) {
+                let path = fs::canonicalize(&path).expect("failed to canonicalize");
+                let path = path.to_str().unwrap().replace('\\', "/");
+                if let Some(ref mut v) = files.get_mut(&path) {
                     tested += 1;
                     let mut iter = right.split("(line ");
                     iter.next();
@@ -3779,7 +3803,7 @@ impl<'test> TestCx<'test> {
         if let Some(nodejs) = &self.config.nodejs {
             let out_dir = self.output_base_dir();
 
-            self.document(&out_dir);
+            self.document(&out_dir, &self.testpaths);
 
             let root = self.config.find_rust_src_root().unwrap();
             let file_stem =
@@ -4095,7 +4119,7 @@ impl<'test> TestCx<'test> {
                 rustc.arg(crate_name);
             }
 
-            let res = self.compose_and_run_compiler(rustc, None);
+            let res = self.compose_and_run_compiler(rustc, None, self.testpaths);
             if !res.status.success() {
                 self.fatal_proc_rec("failed to compile fixed code", &res);
             }
diff --git a/src/tools/compiletest/src/runtest/coverage.rs b/src/tools/compiletest/src/runtest/coverage.rs
index 6ee147da5a965..05191a159801c 100644
--- a/src/tools/compiletest/src/runtest/coverage.rs
+++ b/src/tools/compiletest/src/runtest/coverage.rs
@@ -191,7 +191,7 @@ impl<'test> TestCx<'test> {
 
         rustdoc_cmd.arg(&self.testpaths.file);
 
-        let proc_res = self.compose_and_run_compiler(rustdoc_cmd, None);
+        let proc_res = self.compose_and_run_compiler(rustdoc_cmd, None, self.testpaths);
         if !proc_res.status.success() {
             self.fatal_proc_rec("rustdoc --test failed!", &proc_res)
         }
diff --git a/src/tools/run-make-support/src/env.rs b/src/tools/run-make-support/src/env.rs
index f52524e7d54cd..e6460fb93d3e9 100644
--- a/src/tools/run-make-support/src/env.rs
+++ b/src/tools/run-make-support/src/env.rs
@@ -17,3 +17,10 @@ pub fn env_var_os(name: &str) -> OsString {
         None => panic!("failed to retrieve environment variable {name:?}"),
     }
 }
+
+/// Check if `NO_DEBUG_ASSERTIONS` is set (usually this may be set in CI jobs).
+#[track_caller]
+#[must_use]
+pub fn no_debug_assertions() -> bool {
+    std::env::var_os("NO_DEBUG_ASSERTIONS").is_some()
+}
diff --git a/src/tools/run-make-support/src/external_deps/llvm.rs b/src/tools/run-make-support/src/external_deps/llvm.rs
index 259bb6159461b..c06cefa91a924 100644
--- a/src/tools/run-make-support/src/external_deps/llvm.rs
+++ b/src/tools/run-make-support/src/external_deps/llvm.rs
@@ -42,6 +42,12 @@ pub fn llvm_nm() -> LlvmNm {
     LlvmNm::new()
 }
 
+/// Construct a new `llvm-bcanalyzer` invocation. This assumes that `llvm-bcanalyzer` is available
+/// at `$LLVM_BIN_DIR/llvm-bcanalyzer`.
+pub fn llvm_bcanalyzer() -> LlvmBcanalyzer {
+    LlvmBcanalyzer::new()
+}
+
 /// A `llvm-readobj` invocation builder.
 #[derive(Debug)]
 #[must_use]
@@ -84,12 +90,20 @@ pub struct LlvmNm {
     cmd: Command,
 }
 
+/// A `llvm-bcanalyzer` invocation builder.
+#[derive(Debug)]
+#[must_use]
+pub struct LlvmBcanalyzer {
+    cmd: Command,
+}
+
 crate::macros::impl_common_helpers!(LlvmReadobj);
 crate::macros::impl_common_helpers!(LlvmProfdata);
 crate::macros::impl_common_helpers!(LlvmFilecheck);
 crate::macros::impl_common_helpers!(LlvmObjdump);
 crate::macros::impl_common_helpers!(LlvmAr);
 crate::macros::impl_common_helpers!(LlvmNm);
+crate::macros::impl_common_helpers!(LlvmBcanalyzer);
 
 /// Generate the path to the bin directory of LLVM.
 #[must_use]
@@ -250,6 +264,12 @@ impl LlvmAr {
         self
     }
 
+    /// Extract archive members back to files.
+    pub fn extract(&mut self) -> &mut Self {
+        self.cmd.arg("x");
+        self
+    }
+
     /// Provide an output, then an input file. Bundled in one function, as llvm-ar has
     /// no "--output"-style flag.
     pub fn output_input(&mut self, out: impl AsRef<Path>, input: impl AsRef<Path>) -> &mut Self {
@@ -274,3 +294,19 @@ impl LlvmNm {
         self
     }
 }
+
+impl LlvmBcanalyzer {
+    /// Construct a new `llvm-bcanalyzer` invocation. This assumes that `llvm-bcanalyzer` is available
+    /// at `$LLVM_BIN_DIR/llvm-bcanalyzer`.
+    pub fn new() -> Self {
+        let llvm_bcanalyzer = llvm_bin_dir().join("llvm-bcanalyzer");
+        let cmd = Command::new(llvm_bcanalyzer);
+        Self { cmd }
+    }
+
+    /// Provide an input file.
+    pub fn input<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.cmd.arg(path.as_ref());
+        self
+    }
+}
diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index f28f2a120a44b..97c6bfe86d2bb 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -21,6 +21,7 @@ pub mod run;
 pub mod scoped_run;
 pub mod string;
 pub mod targets;
+pub mod symbols;
 
 // Internally we call our fs-related support module as `fs`, but re-export its content as `rfs`
 // to tests to avoid colliding with commonly used `use std::fs;`.
@@ -48,8 +49,8 @@ pub use cc::{cc, cxx, extra_c_flags, extra_cxx_flags, Cc};
 pub use clang::{clang, Clang};
 pub use htmldocck::htmldocck;
 pub use llvm::{
-    llvm_ar, llvm_filecheck, llvm_nm, llvm_objdump, llvm_profdata, llvm_readobj, LlvmAr,
-    LlvmFilecheck, LlvmNm, LlvmObjdump, LlvmProfdata, LlvmReadobj,
+    llvm_ar, llvm_bcanalyzer, llvm_filecheck, llvm_nm, llvm_objdump, llvm_profdata, llvm_readobj,
+    LlvmAr, LlvmBcanalyzer, LlvmFilecheck, LlvmNm, LlvmObjdump, LlvmProfdata, LlvmReadobj,
 };
 pub use python::python_command;
 pub use rustc::{aux_build, bare_rustc, rustc, Rustc};
diff --git a/src/tools/run-make-support/src/symbols.rs b/src/tools/run-make-support/src/symbols.rs
new file mode 100644
index 0000000000000..fd0c866bcc927
--- /dev/null
+++ b/src/tools/run-make-support/src/symbols.rs
@@ -0,0 +1,44 @@
+use std::path::Path;
+
+use object::{self, Object, ObjectSymbol, SymbolIterator};
+
+/// Iterate through the symbols in an object file.
+///
+/// Uses a callback because `SymbolIterator` does not own its data.
+///
+/// Panics if `path` is not a valid object file readable by the current user.
+pub fn with_symbol_iter<P, F, R>(path: P, func: F) -> R
+where
+    P: AsRef<Path>,
+    F: FnOnce(&mut SymbolIterator<'_, '_>) -> R,
+{
+    let raw_bytes = crate::fs::read(path);
+    let f = object::File::parse(raw_bytes.as_slice()).expect("unable to parse file");
+    let mut iter = f.symbols();
+    func(&mut iter)
+}
+
+/// Check an object file's symbols for substrings.
+///
+/// Returns `true` if any of the symbols found in the object file at
+/// `path` contain a substring listed in `substrings`.
+///
+/// Panics if `path` is not a valid object file readable by the current user.
+pub fn any_symbol_contains(path: impl AsRef<Path>, substrings: &[&str]) -> bool {
+    with_symbol_iter(path, |syms| {
+        for sym in syms {
+            for substring in substrings {
+                if sym
+                    .name_bytes()
+                    .unwrap()
+                    .windows(substring.len())
+                    .any(|x| x == substring.as_bytes())
+                {
+                    eprintln!("{:?} contains {}", sym, substring);
+                    return true;
+                }
+            }
+        }
+        false
+    })
+}
diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index 8747a6265c61e..ed84c68f3c88a 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -4,13 +4,11 @@ run-make/cdylib-dylib-linkage/Makefile
 run-make/cross-lang-lto-clang/Makefile
 run-make/cross-lang-lto-pgo-smoketest/Makefile
 run-make/cross-lang-lto-upstream-rlibs/Makefile
-run-make/cross-lang-lto/Makefile
 run-make/dep-info-doesnt-run-much/Makefile
 run-make/dep-info-spaces/Makefile
 run-make/dep-info/Makefile
 run-make/emit-to-stdout/Makefile
 run-make/extern-fn-reachable/Makefile
-run-make/fmt-write-bloat/Makefile
 run-make/foreign-double-unwind/Makefile
 run-make/foreign-exceptions/Makefile
 run-make/incr-add-rust-src-component/Makefile
@@ -19,13 +17,11 @@ run-make/issue-36710/Makefile
 run-make/issue-47551/Makefile
 run-make/issue-69368/Makefile
 run-make/issue-84395-lto-embed-bitcode/Makefile
-run-make/issue-88756-default-output/Makefile
 run-make/jobserver-error/Makefile
 run-make/libs-through-symlinks/Makefile
 run-make/libtest-json/Makefile
 run-make/libtest-junit/Makefile
 run-make/libtest-thread-limit/Makefile
-run-make/link-cfg/Makefile
 run-make/long-linker-command-lines-cmd-exe/Makefile
 run-make/long-linker-command-lines/Makefile
 run-make/macos-deployment-target/Makefile
diff --git a/tests/run-make/cross-lang-lto/Makefile b/tests/run-make/cross-lang-lto/Makefile
deleted file mode 100644
index 92058f952a9fc..0000000000000
--- a/tests/run-make/cross-lang-lto/Makefile
+++ /dev/null
@@ -1,57 +0,0 @@
-
-include ../tools.mk
-
-# ignore windows due to libLLVM being present in PATH and the PATH and library path being the same
-# (so fixing it is harder). See #57765 for context
-ifndef IS_WINDOWS
-
-# This test makes sure that the object files we generate are actually
-# LLVM bitcode files (as used by linker LTO plugins) when compiling with
-# -Clinker-plugin-lto.
-
-# this only succeeds for bitcode files
-ASSERT_IS_BITCODE_OBJ=("$(LLVM_BIN_DIR)"/llvm-bcanalyzer $(1))
-EXTRACT_OBJS=(cd $(TMPDIR); rm -f ./*.o; "$(LLVM_BIN_DIR)"/llvm-ar x $(1))
-
-BUILD_LIB=$(RUSTC) lib.rs -Copt-level=2 -Clinker-plugin-lto -Ccodegen-units=1
-BUILD_EXE=$(RUSTC) main.rs -Copt-level=2 -Clinker-plugin-lto -Ccodegen-units=1 --emit=obj
-
-all: staticlib staticlib-fat-lto staticlib-thin-lto rlib exe cdylib rdylib
-
-staticlib: lib.rs
-	$(BUILD_LIB) --crate-type=staticlib -o $(TMPDIR)/liblib.a
-	$(call EXTRACT_OBJS, liblib.a)
-	for file in $(TMPDIR)/liblib.*.rcgu.o; do $(call ASSERT_IS_BITCODE_OBJ, $$file); done
-
-staticlib-fat-lto: lib.rs
-	$(BUILD_LIB) --crate-type=staticlib -o $(TMPDIR)/liblib-fat-lto.a -Clto=fat
-	$(call EXTRACT_OBJS, liblib-fat-lto.a)
-	for file in $(TMPDIR)/liblib-fat-lto.*.rcgu.o; do $(call ASSERT_IS_BITCODE_OBJ, $$file); done
-
-staticlib-thin-lto: lib.rs
-	$(BUILD_LIB) --crate-type=staticlib -o $(TMPDIR)/liblib-thin-lto.a -Clto=thin
-	$(call EXTRACT_OBJS, liblib-thin-lto.a)
-	for file in $(TMPDIR)/liblib-thin-lto.*.rcgu.o; do $(call ASSERT_IS_BITCODE_OBJ, $$file); done
-
-rlib: lib.rs
-	$(BUILD_LIB) --crate-type=rlib -o $(TMPDIR)/liblib.rlib
-	$(call EXTRACT_OBJS, liblib.rlib)
-	for file in $(TMPDIR)/liblib.*.rcgu.o; do $(call ASSERT_IS_BITCODE_OBJ, $$file); done
-
-cdylib: lib.rs
-	$(BUILD_LIB) --crate-type=cdylib --emit=obj -o $(TMPDIR)/cdylib.o
-	$(call ASSERT_IS_BITCODE_OBJ, $(TMPDIR)/cdylib.o)
-
-rdylib: lib.rs
-	$(BUILD_LIB) --crate-type=dylib --emit=obj -o $(TMPDIR)/rdylib.o
-	$(call ASSERT_IS_BITCODE_OBJ, $(TMPDIR)/rdylib.o)
-
-exe: lib.rs
-	$(BUILD_EXE) -o $(TMPDIR)/exe.o
-	$(call ASSERT_IS_BITCODE_OBJ, $(TMPDIR)/exe.o)
-
-else
-
-all:
-
-endif
diff --git a/tests/run-make/cross-lang-lto/rmake.rs b/tests/run-make/cross-lang-lto/rmake.rs
new file mode 100644
index 0000000000000..dc376b561e43e
--- /dev/null
+++ b/tests/run-make/cross-lang-lto/rmake.rs
@@ -0,0 +1,110 @@
+// This test checks that the object files we generate are actually
+// LLVM bitcode files (as used by linker LTO plugins) when compiling with
+// -Clinker-plugin-lto.
+// See https://github.com/rust-lang/rust/pull/50000
+
+#![feature(path_file_prefix)]
+
+use std::path::PathBuf;
+
+use run_make_support::{
+    cwd, has_extension, has_prefix, llvm_ar, llvm_bcanalyzer, path, rfs, rust_lib_name, rustc,
+    shallow_find_files, static_lib_name,
+};
+
+fn main() {
+    check_bitcode(LibBuild {
+        source: path("lib.rs"),
+        crate_type: Some("staticlib"),
+        output: path(static_lib_name("liblib")),
+        lto: None,
+        emit_obj: false,
+    });
+    check_bitcode(LibBuild {
+        source: path("lib.rs"),
+        crate_type: Some("staticlib"),
+        output: path(static_lib_name("liblib-fat-lto")),
+        lto: Some("fat"),
+        emit_obj: false,
+    });
+    check_bitcode(LibBuild {
+        source: path("lib.rs"),
+        crate_type: Some("staticlib"),
+        output: path(static_lib_name("liblib-thin-lto")),
+        lto: Some("thin"),
+        emit_obj: false,
+    });
+    check_bitcode(LibBuild {
+        source: path("lib.rs"),
+        crate_type: Some("rlib"),
+        output: path(rust_lib_name("liblib")),
+        lto: None,
+        emit_obj: false,
+    });
+    check_bitcode(LibBuild {
+        source: path("lib.rs"),
+        crate_type: Some("cdylib"),
+        output: path("cdylib.o"),
+        lto: None,
+        emit_obj: true,
+    });
+    check_bitcode(LibBuild {
+        source: path("lib.rs"),
+        crate_type: Some("dylib"),
+        output: path("rdylib.o"),
+        lto: None,
+        emit_obj: true,
+    });
+    check_bitcode(LibBuild {
+        source: path("main.rs"),
+        crate_type: None,
+        output: path("exe.o"),
+        lto: None,
+        emit_obj: true,
+    });
+}
+
+#[track_caller]
+fn check_bitcode(instructions: LibBuild) {
+    let mut rustc = rustc();
+    rustc
+        .input(instructions.source)
+        .output(&instructions.output)
+        .opt_level("2")
+        .codegen_units(1)
+        .arg("-Clinker-plugin-lto");
+    if instructions.emit_obj {
+        rustc.emit("obj");
+    }
+    if let Some(crate_type) = instructions.crate_type {
+        rustc.crate_type(crate_type);
+    }
+    if let Some(lto) = instructions.lto {
+        rustc.arg(format!("-Clto={lto}"));
+    }
+    rustc.run();
+
+    if instructions.output.extension().unwrap() != "o" {
+        // Remove all potential leftover object files, then turn the output into an object file.
+        for object in shallow_find_files(cwd(), |path| has_extension(path, "o")) {
+            rfs::remove_file(object);
+        }
+        llvm_ar().extract().arg(&instructions.output).run();
+    }
+
+    for object in shallow_find_files(cwd(), |path| {
+        has_prefix(path, instructions.output.file_prefix().unwrap().to_str().unwrap())
+            && has_extension(path, "o")
+    }) {
+        // All generated object files should be LLVM bitcode files - this will fail otherwise.
+        llvm_bcanalyzer().input(object).run();
+    }
+}
+
+struct LibBuild {
+    source: PathBuf,
+    crate_type: Option<&'static str>,
+    output: PathBuf,
+    lto: Option<&'static str>,
+    emit_obj: bool,
+}
diff --git a/tests/run-make/fmt-write-bloat/Makefile b/tests/run-make/fmt-write-bloat/Makefile
deleted file mode 100644
index 70e04b9af51fe..0000000000000
--- a/tests/run-make/fmt-write-bloat/Makefile
+++ /dev/null
@@ -1,25 +0,0 @@
-include ../tools.mk
-
-# ignore-windows
-
-ifeq ($(shell $(RUSTC) -vV | grep 'host: $(TARGET)'),)
-
-# Don't run this test when cross compiling.
-all:
-
-else
-
-NM = nm
-
-PANIC_SYMS = panic_bounds_check Debug
-
-# Allow for debug_assert!() in debug builds of std.
-ifdef NO_DEBUG_ASSERTIONS
-PANIC_SYMS += panicking panic_fmt pad_integral Display Debug
-endif
-
-all: main.rs
-	$(RUSTC) $< -O
-	$(NM) $(call RUN_BINFILE,main) | $(CGREP) -v $(PANIC_SYMS)
-
-endif
diff --git a/tests/run-make/fmt-write-bloat/rmake.rs b/tests/run-make/fmt-write-bloat/rmake.rs
new file mode 100644
index 0000000000000..4ae226ec0e234
--- /dev/null
+++ b/tests/run-make/fmt-write-bloat/rmake.rs
@@ -0,0 +1,37 @@
+//! Before #78122, writing any `fmt::Arguments` would trigger the inclusion of `usize` formatting
+//! and padding code in the resulting binary, because indexing used in `fmt::write` would generate
+//! code using `panic_bounds_check`, which prints the index and length.
+//!
+//! These bounds checks are not necessary, as `fmt::Arguments` never contains any out-of-bounds
+//! indexes. The test is a `run-make` test, because it needs to check the result after linking. A
+//! codegen or assembly test doesn't check the parts that will be pulled in from `core` by the
+//! linker.
+//!
+//! In this test, we try to check that the `usize` formatting and padding code are not present in
+//! the final binary by checking that panic symbols such as `panic_bounds_check` are **not**
+//! present.
+//!
+//! Some CI jobs try to run faster by disabling debug assertions (through setting
+//! `NO_DEBUG_ASSERTIONS=1`). If debug assertions are disabled, then we can check for the absence of
+//! additional `usize` formatting and padding related symbols.
+
+// Reason: This test is `ignore-windows` because the `no_std` test (using `#[link(name = "c")])`
+// doesn't link on windows.
+//@ ignore-windows
+//@ ignore-cross-compile
+
+use run_make_support::env::no_debug_assertions;
+use run_make_support::rustc;
+use run_make_support::symbols::any_symbol_contains;
+
+fn main() {
+    rustc().input("main.rs").opt().run();
+    // panic machinery identifiers, these should not appear in the final binary
+    let mut panic_syms = vec!["panic_bounds_check", "Debug"];
+    if no_debug_assertions() {
+        // if debug assertions are allowed, we need to allow these,
+        // otherwise, add them to the list of symbols to deny.
+        panic_syms.extend_from_slice(&["panicking", "panic_fmt", "pad_integral", "Display"]);
+    }
+    assert!(!any_symbol_contains("main", &panic_syms));
+}
diff --git a/tests/run-make/issue-88756-default-output/Makefile b/tests/run-make/issue-88756-default-output/Makefile
deleted file mode 100644
index d1c3d0fe08249..0000000000000
--- a/tests/run-make/issue-88756-default-output/Makefile
+++ /dev/null
@@ -1,4 +0,0 @@
-include ../tools.mk
-
-all:
-	$(BARE_RUSTDOC) 2>&1 | sed -E 's@/nightly/|/beta/|/stable/|/1\.[0-9]+\.[0-9]+/@/$$CHANNEL/@g' | diff - output-default.stdout
diff --git a/tests/run-make/issue-88756-default-output/README.md b/tests/run-make/issue-88756-default-output/README.md
deleted file mode 100644
index 8cbfac4f7d2f1..0000000000000
--- a/tests/run-make/issue-88756-default-output/README.md
+++ /dev/null
@@ -1 +0,0 @@
-This is a test to verify that the default behavior of `rustdoc` is printing out help output instead of erroring out (#88756).
diff --git a/tests/run-make/issue-88756-default-output/x.rs b/tests/run-make/issue-88756-default-output/x.rs
deleted file mode 100644
index 5df7576133a68..0000000000000
--- a/tests/run-make/issue-88756-default-output/x.rs
+++ /dev/null
@@ -1 +0,0 @@
-// nothing to see here
diff --git a/tests/run-make/link-cfg/Makefile b/tests/run-make/link-cfg/Makefile
deleted file mode 100644
index a40997011443c..0000000000000
--- a/tests/run-make/link-cfg/Makefile
+++ /dev/null
@@ -1,23 +0,0 @@
-# ignore-cross-compile
-include ../tools.mk
-
-all: $(call DYLIB,return1) $(call DYLIB,return2) $(call NATIVE_STATICLIB,return3)
-	ls $(TMPDIR)
-	$(BARE_RUSTC) --print cfg --target x86_64-unknown-linux-musl | $(CGREP) crt-static
-
-	$(RUSTC) no-deps.rs --cfg foo
-	$(call RUN,no-deps)
-	$(RUSTC) no-deps.rs --cfg bar
-	$(call RUN,no-deps)
-
-	$(RUSTC) dep.rs
-	$(RUSTC) with-deps.rs --cfg foo
-	$(call RUN,with-deps)
-	$(RUSTC) with-deps.rs --cfg bar
-	$(call RUN,with-deps)
-
-	$(RUSTC) dep-with-staticlib.rs
-	$(RUSTC) with-staticlib-deps.rs --cfg foo
-	$(call RUN,with-staticlib-deps)
-	$(RUSTC) with-staticlib-deps.rs --cfg bar
-	$(call RUN,with-staticlib-deps)
diff --git a/tests/run-make/link-cfg/rmake.rs b/tests/run-make/link-cfg/rmake.rs
new file mode 100644
index 0000000000000..732de5dbd0b80
--- /dev/null
+++ b/tests/run-make/link-cfg/rmake.rs
@@ -0,0 +1,43 @@
+// The `#[link(cfg(..))]` annotation means that the `#[link]`
+// directive is only active in a compilation unit if that `cfg` value is satisfied.
+// For example, when compiling an rlib, these directives are just encoded and
+// ignored for dylibs, and all staticlibs are continued to be put into the rlib as
+// usual. When placing that rlib into a staticlib, executable, or dylib, however,
+// the `cfg` is evaluated *as if it were defined in the final artifact* and the
+// library is decided to be linked or not.
+// This test exercises this new feature by testing it with no dependencies, then
+// with only dynamic libraries, then with both a staticlib and dylibs. Compilation
+// and execution should be successful.
+// See https://github.com/rust-lang/rust/pull/37545
+
+//@ ignore-cross-compile
+// Reason: the compiled binary is executed
+
+use run_make_support::{bare_rustc, build_native_dynamic_lib, build_native_static_lib, run, rustc};
+
+fn main() {
+    build_native_dynamic_lib("return1");
+    build_native_dynamic_lib("return2");
+    build_native_static_lib("return3");
+    bare_rustc()
+        .print("cfg")
+        .target("x86_64-unknown-linux-musl")
+        .run()
+        .assert_stdout_contains("crt-static");
+    rustc().input("no-deps.rs").cfg("foo").run();
+    run("no-deps");
+    rustc().input("no-deps.rs").cfg("bar").run();
+    run("no-deps");
+
+    rustc().input("dep.rs").run();
+    rustc().input("with-deps.rs").cfg("foo").run();
+    run("with-deps");
+    rustc().input("with-deps.rs").cfg("bar").run();
+    run("with-deps");
+
+    rustc().input("dep-with-staticlib.rs").run();
+    rustc().input("with-staticlib-deps.rs").cfg("foo").run();
+    run("with-staticlib-deps");
+    rustc().input("with-staticlib-deps.rs").cfg("bar").run();
+    run("with-staticlib-deps");
+}
diff --git a/tests/run-make/issue-88756-default-output/output-default.stdout b/tests/run-make/rustdoc-default-output/output-default.stdout
similarity index 100%
rename from tests/run-make/issue-88756-default-output/output-default.stdout
rename to tests/run-make/rustdoc-default-output/output-default.stdout
diff --git a/tests/run-make/rustdoc-default-output/rmake.rs b/tests/run-make/rustdoc-default-output/rmake.rs
new file mode 100644
index 0000000000000..940c089ecd4ab
--- /dev/null
+++ b/tests/run-make/rustdoc-default-output/rmake.rs
@@ -0,0 +1,16 @@
+// Calling rustdoc with no arguments, which should bring up a help menu, used to
+// cause an error as rustdoc expects an input file. Fixed in #98331, this test
+// ensures the output of rustdoc's help menu is as expected.
+// See https://github.com/rust-lang/rust/issues/88756
+
+use run_make_support::{bare_rustdoc, diff};
+
+fn main() {
+    let out = bare_rustdoc().run().stdout_utf8();
+    diff()
+        .expected_file("output-default.stdout")
+        .actual_text("actual", out)
+        // replace the channel type in the URL with $CHANNEL
+        .normalize(r"/nightly/|beta/|stable/|1\.[0-9]+\.[0-9]+/", "/$$CHANNEL/")
+        .run();
+}
diff --git a/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/auxiliary/q.rs b/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/auxiliary/q.rs
new file mode 100644
index 0000000000000..5d0881029cb2f
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/auxiliary/q.rs
@@ -0,0 +1,2 @@
+//@ build-aux-docs
+pub struct Quebec;
diff --git a/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/auxiliary/t.rs b/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/auxiliary/t.rs
new file mode 100644
index 0000000000000..fab9ec4a92b96
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/auxiliary/t.rs
@@ -0,0 +1,4 @@
+//@ aux-build:q.rs
+//@ build-aux-docs
+extern crate q;
+pub trait Tango {}
diff --git a/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/s.rs b/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/s.rs
new file mode 100644
index 0000000000000..85c460ace642f
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-transitive-no-index/s.rs
@@ -0,0 +1,16 @@
+//@ aux-build:t.rs
+//@ build-aux-docs
+//@ has q/struct.Quebec.html
+//@ has s/struct.Sierra.html
+//@ has t/trait.Tango.html
+//@ hasraw s/struct.Sierra.html 'Tango'
+//@ hasraw trait.impl/t/trait.Tango.js 'struct.Sierra.html'
+//@ hasraw search-index.js 'Tango'
+//@ hasraw search-index.js 'Sierra'
+//@ hasraw search-index.js 'Quebec'
+
+// We document multiple crates into the same output directory, which
+// merges the cross-crate information. Everything is available.
+extern crate t;
+pub struct Sierra;
+impl t::Tango for Sierra {}
diff --git a/tests/rustdoc/cross-crate-info/cargo-transitive/auxiliary/q.rs b/tests/rustdoc/cross-crate-info/cargo-transitive/auxiliary/q.rs
new file mode 100644
index 0000000000000..932a0b17206d6
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-transitive/auxiliary/q.rs
@@ -0,0 +1,5 @@
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+pub struct Quebec;
diff --git a/tests/rustdoc/cross-crate-info/cargo-transitive/auxiliary/t.rs b/tests/rustdoc/cross-crate-info/cargo-transitive/auxiliary/t.rs
new file mode 100644
index 0000000000000..c21a59c65188f
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-transitive/auxiliary/t.rs
@@ -0,0 +1,7 @@
+//@ aux-build:q.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+extern crate q;
+pub trait Tango {}
diff --git a/tests/rustdoc/cross-crate-info/cargo-transitive/s.rs b/tests/rustdoc/cross-crate-info/cargo-transitive/s.rs
new file mode 100644
index 0000000000000..68bfc34883bd8
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-transitive/s.rs
@@ -0,0 +1,24 @@
+//@ aux-build:t.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+//@ has index.html
+//@ has index.html '//h1' 'List of all crates'
+//@ has index.html '//ul[@class="all-items"]//a[@href="q/index.html"]' 'q'
+//@ has index.html '//ul[@class="all-items"]//a[@href="s/index.html"]' 's'
+//@ has index.html '//ul[@class="all-items"]//a[@href="t/index.html"]' 't'
+//@ has q/struct.Quebec.html
+//@ has s/struct.Sierra.html
+//@ has t/trait.Tango.html
+//@ hasraw s/struct.Sierra.html 'Tango'
+//@ hasraw trait.impl/t/trait.Tango.js 'struct.Sierra.html'
+//@ hasraw search-index.js 'Tango'
+//@ hasraw search-index.js 'Sierra'
+//@ hasraw search-index.js 'Quebec'
+
+// We document multiple crates into the same output directory, which
+// merges the cross-crate information. Everything is available.
+extern crate t;
+pub struct Sierra;
+impl t::Tango for Sierra {}
diff --git a/tests/rustdoc/cross-crate-info/cargo-two-no-index/auxiliary/f.rs b/tests/rustdoc/cross-crate-info/cargo-two-no-index/auxiliary/f.rs
new file mode 100644
index 0000000000000..abc580a388cd2
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-two-no-index/auxiliary/f.rs
@@ -0,0 +1,2 @@
+//@ build-aux-docs
+pub trait Foxtrot {}
diff --git a/tests/rustdoc/cross-crate-info/cargo-two-no-index/e.rs b/tests/rustdoc/cross-crate-info/cargo-two-no-index/e.rs
new file mode 100644
index 0000000000000..c93298f969eab
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-two-no-index/e.rs
@@ -0,0 +1,14 @@
+//@ aux-build:f.rs
+//@ build-aux-docs
+//@ has e/enum.Echo.html
+//@ has f/trait.Foxtrot.html
+//@ hasraw e/enum.Echo.html 'Foxtrot'
+//@ hasraw trait.impl/f/trait.Foxtrot.js 'enum.Echo.html'
+//@ hasraw search-index.js 'Foxtrot'
+//@ hasraw search-index.js 'Echo'
+
+// document two crates in the same way that cargo does. do not provide
+// --enable-index-page
+extern crate f;
+pub enum Echo {}
+impl f::Foxtrot for Echo {}
diff --git a/tests/rustdoc/cross-crate-info/cargo-two/auxiliary/f.rs b/tests/rustdoc/cross-crate-info/cargo-two/auxiliary/f.rs
new file mode 100644
index 0000000000000..a2a7033b13112
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-two/auxiliary/f.rs
@@ -0,0 +1,5 @@
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+pub trait Foxtrot {}
diff --git a/tests/rustdoc/cross-crate-info/cargo-two/e.rs b/tests/rustdoc/cross-crate-info/cargo-two/e.rs
new file mode 100644
index 0000000000000..00f86cbc34889
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/cargo-two/e.rs
@@ -0,0 +1,21 @@
+//@ aux-build:f.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+//@ has index.html
+//@ has index.html '//h1' 'List of all crates'
+//@ has index.html '//ul[@class="all-items"]//a[@href="f/index.html"]' 'f'
+//@ has index.html '//ul[@class="all-items"]//a[@href="e/index.html"]' 'e'
+//@ has e/enum.Echo.html
+//@ has f/trait.Foxtrot.html
+//@ hasraw e/enum.Echo.html 'Foxtrot'
+//@ hasraw trait.impl/f/trait.Foxtrot.js 'enum.Echo.html'
+//@ hasraw search-index.js 'Foxtrot'
+//@ hasraw search-index.js 'Echo'
+
+// document two crates in the same way that cargo does, writing them both
+// into the same output directory
+extern crate f;
+pub enum Echo {}
+impl f::Foxtrot for Echo {}
diff --git a/tests/rustdoc/cross-crate-info/index-on-last/auxiliary/f.rs b/tests/rustdoc/cross-crate-info/index-on-last/auxiliary/f.rs
new file mode 100644
index 0000000000000..abc580a388cd2
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/index-on-last/auxiliary/f.rs
@@ -0,0 +1,2 @@
+//@ build-aux-docs
+pub trait Foxtrot {}
diff --git a/tests/rustdoc/cross-crate-info/index-on-last/e.rs b/tests/rustdoc/cross-crate-info/index-on-last/e.rs
new file mode 100644
index 0000000000000..ffee898cd966d
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/index-on-last/e.rs
@@ -0,0 +1,20 @@
+//@ aux-build:f.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+//@ has index.html
+//@ has index.html '//h1' 'List of all crates'
+//@ has index.html '//ul[@class="all-items"]//a[@href="f/index.html"]' 'f'
+//@ has index.html '//ul[@class="all-items"]//a[@href="e/index.html"]' 'e'
+//@ has e/enum.Echo.html
+//@ has f/trait.Foxtrot.html
+//@ hasraw e/enum.Echo.html 'Foxtrot'
+//@ hasraw trait.impl/f/trait.Foxtrot.js 'enum.Echo.html'
+//@ hasraw search-index.js 'Foxtrot'
+//@ hasraw search-index.js 'Echo'
+
+// only declare --enable-index-page to the last rustdoc invocation
+extern crate f;
+pub enum Echo {}
+impl f::Foxtrot for Echo {}
diff --git a/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/q.rs b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/q.rs
new file mode 100644
index 0000000000000..932a0b17206d6
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/q.rs
@@ -0,0 +1,5 @@
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+pub struct Quebec;
diff --git a/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/r.rs b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/r.rs
new file mode 100644
index 0000000000000..2c0db2abc53d9
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/r.rs
@@ -0,0 +1,7 @@
+//@ aux-build:s.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+extern crate s;
+pub type Romeo = s::Sierra;
diff --git a/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/s.rs b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/s.rs
new file mode 100644
index 0000000000000..355d3f1aaa883
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/s.rs
@@ -0,0 +1,8 @@
+//@ aux-build:t.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+extern crate t;
+pub struct Sierra;
+impl t::Tango for Sierra {}
diff --git a/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/t.rs b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/t.rs
new file mode 100644
index 0000000000000..c21a59c65188f
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/kitchen-sink/auxiliary/t.rs
@@ -0,0 +1,7 @@
+//@ aux-build:q.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+extern crate q;
+pub trait Tango {}
diff --git a/tests/rustdoc/cross-crate-info/kitchen-sink/i.rs b/tests/rustdoc/cross-crate-info/kitchen-sink/i.rs
new file mode 100644
index 0000000000000..bcb9464795af2
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/kitchen-sink/i.rs
@@ -0,0 +1,30 @@
+//@ aux-build:r.rs
+//@ aux-build:q.rs
+//@ aux-build:t.rs
+//@ aux-build:s.rs
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+//@ has index.html '//h1' 'List of all crates'
+//@ has index.html
+//@ has index.html '//ul[@class="all-items"]//a[@href="i/index.html"]' 'i'
+//@ has index.html '//ul[@class="all-items"]//a[@href="q/index.html"]' 'q'
+//@ has index.html '//ul[@class="all-items"]//a[@href="r/index.html"]' 'r'
+//@ has index.html '//ul[@class="all-items"]//a[@href="s/index.html"]' 's'
+//@ has index.html '//ul[@class="all-items"]//a[@href="t/index.html"]' 't'
+//@ has q/struct.Quebec.html
+//@ has r/type.Romeo.html
+//@ has s/struct.Sierra.html
+//@ has t/trait.Tango.html
+//@ hasraw s/struct.Sierra.html 'Tango'
+//@ hasraw trait.impl/t/trait.Tango.js 'struct.Sierra.html'
+//@ hasraw search-index.js 'Quebec'
+//@ hasraw search-index.js 'Romeo'
+//@ hasraw search-index.js 'Sierra'
+//@ hasraw search-index.js 'Tango'
+//@ has type.impl/s/struct.Sierra.js
+//@ hasraw type.impl/s/struct.Sierra.js 'Tango'
+//@ hasraw type.impl/s/struct.Sierra.js 'Romeo'
+
+// document everything in the default mode
diff --git a/tests/rustdoc/cross-crate-info/single-crate-baseline/q.rs b/tests/rustdoc/cross-crate-info/single-crate-baseline/q.rs
new file mode 100644
index 0000000000000..c5e3dc0a0f4e5
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/single-crate-baseline/q.rs
@@ -0,0 +1,12 @@
+//@ build-aux-docs
+//@ doc-flags:--enable-index-page
+//@ doc-flags:-Zunstable-options
+
+//@ has index.html
+//@ has index.html '//h1' 'List of all crates'
+//@ has index.html '//ul[@class="all-items"]//a[@href="q/index.html"]' 'q'
+//@ has q/struct.Quebec.html
+//@ hasraw search-index.js 'Quebec'
+
+// there's nothing cross-crate going on here
+pub struct Quebec;
diff --git a/tests/rustdoc/cross-crate-info/single-crate-no-index/q.rs b/tests/rustdoc/cross-crate-info/single-crate-no-index/q.rs
new file mode 100644
index 0000000000000..d3e71fa0ce35f
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/single-crate-no-index/q.rs
@@ -0,0 +1,6 @@
+//@ build-aux-docs
+//@ has q/struct.Quebec.html
+//@ hasraw search-index.js 'Quebec'
+
+// there's nothing cross-crate going on here
+pub struct Quebec;
diff --git a/tests/rustdoc/cross-crate-info/transitive/auxiliary/q.rs b/tests/rustdoc/cross-crate-info/transitive/auxiliary/q.rs
new file mode 100644
index 0000000000000..5d0881029cb2f
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/transitive/auxiliary/q.rs
@@ -0,0 +1,2 @@
+//@ build-aux-docs
+pub struct Quebec;
diff --git a/tests/rustdoc/cross-crate-info/transitive/auxiliary/t.rs b/tests/rustdoc/cross-crate-info/transitive/auxiliary/t.rs
new file mode 100644
index 0000000000000..fab9ec4a92b96
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/transitive/auxiliary/t.rs
@@ -0,0 +1,4 @@
+//@ aux-build:q.rs
+//@ build-aux-docs
+extern crate q;
+pub trait Tango {}
diff --git a/tests/rustdoc/cross-crate-info/transitive/s.rs b/tests/rustdoc/cross-crate-info/transitive/s.rs
new file mode 100644
index 0000000000000..0a4e5f646ddaa
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/transitive/s.rs
@@ -0,0 +1,6 @@
+//@ aux-build:t.rs
+//@ build-aux-docs
+// simple test to see if we support building transitive crates
+extern crate t;
+pub struct Sierra;
+impl t::Tango for Sierra {}
diff --git a/tests/rustdoc/cross-crate-info/two/auxiliary/f.rs b/tests/rustdoc/cross-crate-info/two/auxiliary/f.rs
new file mode 100644
index 0000000000000..abc580a388cd2
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/two/auxiliary/f.rs
@@ -0,0 +1,2 @@
+//@ build-aux-docs
+pub trait Foxtrot {}
diff --git a/tests/rustdoc/cross-crate-info/two/e.rs b/tests/rustdoc/cross-crate-info/two/e.rs
new file mode 100644
index 0000000000000..9665af62706d1
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/two/e.rs
@@ -0,0 +1,6 @@
+//@ aux-build:f.rs
+//@ build-aux-docs
+// simple test to assert that we can do a two-level aux-build
+extern crate f;
+pub enum Echo {}
+impl f::Foxtrot for Echo {}
diff --git a/tests/rustdoc/cross-crate-info/working-dir-examples/q.rs b/tests/rustdoc/cross-crate-info/working-dir-examples/q.rs
new file mode 100644
index 0000000000000..a7ab062fd9e28
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/working-dir-examples/q.rs
@@ -0,0 +1,10 @@
+//@ build-aux-docs
+//@ doc-flags:--scrape-examples-output-path=examples
+//@ doc-flags:--scrape-examples-target-crate=q
+//@ doc-flags:-Zunstable-options
+
+//@ has examples
+
+// where will --scrape-examples-output-path resolve the path to be?
+// should be the root output directory
+pub struct Quebec;
diff --git a/tests/rustdoc/cross-crate-info/write-docs-somewhere-else/auxiliary/f.rs b/tests/rustdoc/cross-crate-info/write-docs-somewhere-else/auxiliary/f.rs
new file mode 100644
index 0000000000000..f8c9adcaf9cad
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/write-docs-somewhere-else/auxiliary/f.rs
@@ -0,0 +1,3 @@
+//@ build-aux-docs
+//@ unique-doc-out-dir
+pub trait Foxtrot {}
diff --git a/tests/rustdoc/cross-crate-info/write-docs-somewhere-else/e.rs b/tests/rustdoc/cross-crate-info/write-docs-somewhere-else/e.rs
new file mode 100644
index 0000000000000..9dcec211e1787
--- /dev/null
+++ b/tests/rustdoc/cross-crate-info/write-docs-somewhere-else/e.rs
@@ -0,0 +1,14 @@
+//@ aux-build:f.rs
+//@ build-aux-docs
+//@ has e/enum.Echo.html
+//@ !has f/trait.Foxtrot.html
+//@ hasraw e/enum.Echo.html 'Foxtrot'
+//@ hasraw trait.impl/f/trait.Foxtrot.js 'enum.Echo.html'
+//@ !hasraw search-index.js 'Foxtrot'
+//@ hasraw search-index.js 'Echo'
+
+// test the fact that our test runner will document this crate somewhere
+// else
+extern crate f;
+pub enum Echo {}
+impl f::Foxtrot for Echo {}