Auto merge of #128356 - Oneirical:real-estate-reaLTOr, r=jieyouxu

Migrate `cross-lang-lto-clang` and `cross-lang-lto-pgo-smoketest` `run-make` tests to rmake

Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

This has the same problem outlined by #126180, where the tests do not actually run as no test-running CI enviroment has `RUSTBUILD_FORCE_CLANG_BASED_TESTS` set.

However, I still find it interesting to turn the Makefiles into the rmake format until the Clang issue is fixed.

This should technically be tested on MSVC... if MSVC actually ran Clang tests.

try-job: x86_64-gnu-debug

13 files changed, 200 insertions, 121 deletions

diff --git a/src/tools/run-make-support/src/external_deps/clang.rs b/src/tools/run-make-support/src/external_deps/clang.rs
index 2b0712541cd..2d110c6825e 100644
--- a/src/tools/run-make-support/src/external_deps/clang.rs
+++ b/src/tools/run-make-support/src/external_deps/clang.rs
@@ -1,7 +1,7 @@
 use std::path::Path;
 
 use crate::command::Command;
-use crate::{bin_name, env_var};
+use crate::{bin_name, cwd, env_var};
 
 /// Construct a new `clang` invocation. `clang` is not always available for all targets.
 #[track_caller]
@@ -23,7 +23,8 @@ impl Clang {
     #[track_caller]
     pub fn new() -> Self {
         let clang = env_var("CLANG");
-        let cmd = Command::new(clang);
+        let mut cmd = Command::new(clang);
+        cmd.arg("-L").arg(cwd());
         Self { cmd }
     }
 
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 c06cefa91a9..56021cec269 100644
--- a/src/tools/run-make-support/src/external_deps/llvm.rs
+++ b/src/tools/run-make-support/src/external_deps/llvm.rs
@@ -246,6 +246,12 @@ impl LlvmObjdump {
         self.cmd.arg(path.as_ref());
         self
     }
+
+    /// Disassemble all executable sections found in the input files.
+    pub fn disassemble(&mut self) -> &mut Self {
+        self.cmd.arg("-d");
+        self
+    }
 }
 
 impl LlvmAr {
diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index 2561df2e477..a04e239abb0 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -1,8 +1,6 @@
 run-make/branch-protection-check-IBT/Makefile
 run-make/cat-and-grep-sanity-check/Makefile
 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/dep-info-doesnt-run-much/Makefile
 run-make/dep-info-spaces/Makefile
diff --git a/tests/run-make/cross-lang-lto-clang/Makefile b/tests/run-make/cross-lang-lto-clang/Makefile
deleted file mode 100644
index acf49c8f5c8..00000000000
--- a/tests/run-make/cross-lang-lto-clang/Makefile
+++ /dev/null
@@ -1,25 +0,0 @@
-# needs-force-clang-based-tests
-
-# This test makes sure that cross-language inlining actually works by checking
-# the generated machine code.
-
-include ../tools.mk
-
-all: cpp-executable rust-executable
-
-cpp-executable:
-	$(RUSTC) -Clinker-plugin-lto=on -o $(TMPDIR)/librustlib-xlto.a -Copt-level=2 -Ccodegen-units=1 ./rustlib.rs
-	$(CLANG) -flto=thin -fuse-ld=lld -L $(TMPDIR) -lrustlib-xlto -o $(TMPDIR)/cmain ./cmain.c -O3
-	# Make sure we don't find a call instruction to the function we expect to
-	# always be inlined.
-	"$(LLVM_BIN_DIR)"/llvm-objdump -d $(TMPDIR)/cmain | $(CGREP) -v -e "call.*rust_always_inlined"
-	# As a sanity check, make sure we do find a call instruction to a
-	# non-inlined function
-	"$(LLVM_BIN_DIR)"/llvm-objdump -d $(TMPDIR)/cmain | $(CGREP) -e "call.*rust_never_inlined"
-
-rust-executable:
-	$(CLANG) ./clib.c -flto=thin -c -o $(TMPDIR)/clib.o -O2
-	(cd $(TMPDIR); $(AR) crus ./libxyz.a ./clib.o)
-	$(RUSTC) -Clinker-plugin-lto=on -L$(TMPDIR) -Copt-level=2 -Clinker=$(CLANG) -Clink-arg=-fuse-ld=lld ./main.rs -o $(TMPDIR)/rsmain
-	"$(LLVM_BIN_DIR)"/llvm-objdump -d $(TMPDIR)/rsmain | $(CGREP) -e "call.*c_never_inlined"
-	"$(LLVM_BIN_DIR)"/llvm-objdump -d $(TMPDIR)/rsmain | $(CGREP) -v -e "call.*c_always_inlined"
diff --git a/tests/run-make/cross-lang-lto-clang/rmake.rs b/tests/run-make/cross-lang-lto-clang/rmake.rs
new file mode 100644
index 00000000000..1b15a54aacb
--- /dev/null
+++ b/tests/run-make/cross-lang-lto-clang/rmake.rs
@@ -0,0 +1,62 @@
+// This test checks that cross-language inlining actually works by checking
+// the generated machine code.
+// See https://github.com/rust-lang/rust/pull/57514
+
+//@ needs-force-clang-based-tests
+// NOTE(#126180): This test only runs on `x86_64-gnu-debug`, because that CI job sets
+// RUSTBUILD_FORCE_CLANG_BASED_TESTS and only runs tests which contain "clang" in their
+// name.
+
+use run_make_support::{clang, env_var, llvm_ar, llvm_objdump, rustc, static_lib_name};
+
+fn main() {
+    rustc()
+        .linker_plugin_lto("on")
+        .output(static_lib_name("rustlib-xlto"))
+        .opt_level("2")
+        .codegen_units(1)
+        .input("rustlib.rs")
+        .run();
+    clang()
+        .lto("thin")
+        .use_ld("lld")
+        .arg("-lrustlib-xlto")
+        .out_exe("cmain")
+        .input("cmain.c")
+        .arg("-O3")
+        .run();
+    // Make sure we don't find a call instruction to the function we expect to
+    // always be inlined.
+    llvm_objdump()
+        .disassemble()
+        .input("cmain")
+        .run()
+        .assert_stdout_not_contains_regex("call.*rust_always_inlined");
+    // As a sanity check, make sure we do find a call instruction to a
+    // non-inlined function
+    llvm_objdump()
+        .disassemble()
+        .input("cmain")
+        .run()
+        .assert_stdout_contains_regex("call.*rust_never_inlined");
+    clang().input("clib.c").lto("thin").arg("-c").out_exe("clib.o").arg("-O2").run();
+    llvm_ar().obj_to_ar().output_input(static_lib_name("xyz"), "clib.o").run();
+    rustc()
+        .linker_plugin_lto("on")
+        .opt_level("2")
+        .linker(&env_var("CLANG"))
+        .link_arg("-fuse-ld=lld")
+        .input("main.rs")
+        .output("rsmain")
+        .run();
+    llvm_objdump()
+        .disassemble()
+        .input("rsmain")
+        .run()
+        .assert_stdout_not_contains_regex("call.*c_always_inlined");
+    llvm_objdump()
+        .disassemble()
+        .input("rsmain")
+        .run()
+        .assert_stdout_contains_regex("call.*c_never_inlined");
+}
diff --git a/tests/run-make/cross-lang-lto-pgo-smoketest/clib.c b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/clib.c
index 90f33f24dc4..90f33f24dc4 100644
--- a/tests/run-make/cross-lang-lto-pgo-smoketest/clib.c
+++ b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/clib.c
diff --git a/tests/run-make/cross-lang-lto-pgo-smoketest/cmain.c b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/cmain.c
index e3f24828be3..e3f24828be3 100644
--- a/tests/run-make/cross-lang-lto-pgo-smoketest/cmain.c
+++ b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/cmain.c
diff --git a/tests/run-make/cross-lang-lto-pgo-smoketest/main.rs b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/main.rs
index 8129dcb85d9..8129dcb85d9 100644
--- a/tests/run-make/cross-lang-lto-pgo-smoketest/main.rs
+++ b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/main.rs
diff --git a/tests/run-make/cross-lang-lto-pgo-smoketest-clang/rmake.rs b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/rmake.rs
new file mode 100644
index 00000000000..03c9af4bb89
--- /dev/null
+++ b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/rmake.rs
@@ -0,0 +1,120 @@
+// This test makes sure that cross-language inlining can be used in conjunction
+// with profile-guided optimization. The test only tests that the whole workflow
+// can be executed without anything crashing. It does not test whether PGO or
+// xLTO have any specific effect on the generated code.
+// See https://github.com/rust-lang/rust/pull/61036
+
+//@ needs-force-clang-based-tests
+// NOTE(#126180): This test would only run on `x86_64-gnu-debug`, because that CI job sets
+// RUSTBUILD_FORCE_CLANG_BASED_TESTS and only runs tests which contain "clang" in their
+// name.
+
+//@ needs-profiler-support
+// FIXME(Oneirical): Except that due to the reliance on llvm-profdata, this test
+// never runs, because `x86_64-gnu-debug` does not have the `profiler_builtins` crate.
+
+//FIXME(Oneirical): There was a strange workaround for MSVC on this test
+// which added -C panic=abort to every RUSTC call. It was justified as follows:
+
+// "LLVM doesn't support instrumenting binaries that use SEH:
+// https://bugs.llvm.org/show_bug.cgi?id=41279
+// Things work fine with -Cpanic=abort though."
+
+// This isn't very pertinent, however, as the test does not get run on any
+// MSVC platforms.
+
+use run_make_support::{
+    clang, env_var, has_extension, has_prefix, llvm_ar, llvm_profdata, rfs, run, rustc,
+    shallow_find_files, static_lib_name,
+};
+
+fn main() {
+    rustc()
+        .linker_plugin_lto("on")
+        .output(static_lib_name("rustlib-xlto"))
+        .opt_level("3")
+        .codegen_units(1)
+        .input("rustlib.rs")
+        .arg("-Cprofile-generate=cpp-profdata")
+        .run();
+    clang()
+        .lto("thin")
+        .arg("-fprofile-generate=cpp-profdata")
+        .use_ld("lld")
+        .arg("-lrustlib-xlto")
+        .out_exe("cmain")
+        .input("cmain.c")
+        .arg("-O3")
+        .run();
+    run("cmain");
+    // Postprocess the profiling data so it can be used by the compiler
+    let profraw_files = shallow_find_files("cpp-profdata", |path| {
+        has_prefix(path, "default") && has_extension(path, "profraw")
+    });
+    let profraw_file = profraw_files.get(0).unwrap();
+    llvm_profdata().merge().output("cpp-profdata/merged.profdata").input(profraw_file).run();
+    rustc()
+        .linker_plugin_lto("on")
+        .profile_use("cpp-profdata/merged.profdata")
+        .output(static_lib_name("rustlib-xlto"))
+        .opt_level("3")
+        .codegen_units(1)
+        .input("rustlib.rs")
+        .run();
+    clang()
+        .lto("thin")
+        .arg("-fprofile-use=cpp-profdata/merged.profdata")
+        .use_ld("lld")
+        .arg("-lrustlib-xlto")
+        .out_exe("cmain")
+        .input("cmain.c")
+        .arg("-O3")
+        .run();
+
+    clang()
+        .input("clib.c")
+        .arg("-fprofile-generate=rs-profdata")
+        .lto("thin")
+        .arg("-c")
+        .out_exe("clib.o")
+        .arg("-O3")
+        .run();
+    llvm_ar().obj_to_ar().output_input(static_lib_name("xyz"), "clib.o").run();
+    rustc()
+        .linker_plugin_lto("on")
+        .opt_level("3")
+        .codegen_units(1)
+        .arg("-Cprofile-generate=rs-profdata")
+        .linker(&env_var("CLANG"))
+        .link_arg("-fuse-ld=lld")
+        .input("main.rs")
+        .output("rsmain")
+        .run();
+    run("rsmain");
+    // Postprocess the profiling data so it can be used by the compiler
+    let profraw_files = shallow_find_files("rs-profdata", |path| {
+        has_prefix(path, "default") && has_extension(path, "profraw")
+    });
+    let profraw_file = profraw_files.get(0).unwrap();
+    llvm_profdata().merge().output("rs-profdata/merged.profdata").input(profraw_file).run();
+    clang()
+        .input("clib.c")
+        .arg("-fprofile-use=rs-profdata/merged.profdata")
+        .arg("-c")
+        .lto("thin")
+        .out_exe("clib.o")
+        .arg("-O3")
+        .run();
+    rfs::remove_file(static_lib_name("xyz"));
+    llvm_ar().obj_to_ar().output_input(static_lib_name("xyz"), "clib.o").run();
+    rustc()
+        .linker_plugin_lto("on")
+        .opt_level("3")
+        .codegen_units(1)
+        .arg("-Cprofile-use=rs-profdata/merged.profdata")
+        .linker(&env_var("CLANG"))
+        .link_arg("-fuse-ld=lld")
+        .input("main.rs")
+        .output("rsmain")
+        .run();
+}
diff --git a/tests/run-make/cross-lang-lto-pgo-smoketest/rustlib.rs b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/rustlib.rs
index 9aff29ef9bb..9aff29ef9bb 100644
--- a/tests/run-make/cross-lang-lto-pgo-smoketest/rustlib.rs
+++ b/tests/run-make/cross-lang-lto-pgo-smoketest-clang/rustlib.rs
diff --git a/tests/run-make/cross-lang-lto-pgo-smoketest/Makefile b/tests/run-make/cross-lang-lto-pgo-smoketest/Makefile
deleted file mode 100644
index 738e23f9c66..00000000000
--- a/tests/run-make/cross-lang-lto-pgo-smoketest/Makefile
+++ /dev/null
@@ -1,90 +0,0 @@
-# needs-force-clang-based-tests
-
-# FIXME(#126180): This test doesn't actually run anywhere, because the only
-# CI job that sets RUSTBUILD_FORCE_CLANG_BASED_TESTS runs very few tests.
-
-# This test makes sure that cross-language inlining can be used in conjunction
-# with profile-guided optimization. The test only tests that the whole workflow
-# can be executed without anything crashing. It does not test whether PGO or
-# xLTO have any specific effect on the generated code.
-
-include ../tools.mk
-
-COMMON_FLAGS=-Copt-level=3 -Ccodegen-units=1
-
-# LLVM doesn't support instrumenting binaries that use SEH:
-# https://bugs.llvm.org/show_bug.cgi?id=41279
-#
-# Things work fine with -Cpanic=abort though.
-ifdef IS_MSVC
-COMMON_FLAGS+= -Cpanic=abort
-endif
-
-all: cpp-executable rust-executable
-
-cpp-executable:
-	$(RUSTC) -Clinker-plugin-lto=on \
-	         -Cprofile-generate="$(TMPDIR)"/cpp-profdata \
-	         -o "$(TMPDIR)"/librustlib-xlto.a \
-	         $(COMMON_FLAGS) \
-	         ./rustlib.rs
-	$(CLANG) -flto=thin \
-	         -fprofile-generate="$(TMPDIR)"/cpp-profdata \
-	         -fuse-ld=lld \
-	         -L "$(TMPDIR)" \
-	         -lrustlib-xlto \
-	         -o "$(TMPDIR)"/cmain \
-	         -O3 \
-	         ./cmain.c
-	$(TMPDIR)/cmain
-	# Postprocess the profiling data so it can be used by the compiler
-	"$(LLVM_BIN_DIR)"/llvm-profdata merge \
-		-o "$(TMPDIR)"/cpp-profdata/merged.profdata \
-		"$(TMPDIR)"/cpp-profdata/default_*.profraw
-	$(RUSTC) -Clinker-plugin-lto=on \
-	         -Cprofile-use="$(TMPDIR)"/cpp-profdata/merged.profdata \
-	         -o "$(TMPDIR)"/librustlib-xlto.a \
-	         $(COMMON_FLAGS) \
-	         ./rustlib.rs
-	$(CLANG) -flto=thin \
-	         -fprofile-use="$(TMPDIR)"/cpp-profdata/merged.profdata \
-	         -fuse-ld=lld \
-	         -L "$(TMPDIR)" \
-	         -lrustlib-xlto \
-	         -o "$(TMPDIR)"/cmain \
-	         -O3 \
-	         ./cmain.c
-
-rust-executable:
-	exit
-	$(CLANG) ./clib.c -fprofile-generate="$(TMPDIR)"/rs-profdata -flto=thin -c -o $(TMPDIR)/clib.o -O3
-	(cd $(TMPDIR); $(AR) crus ./libxyz.a ./clib.o)
-	$(RUSTC) -Clinker-plugin-lto=on \
-	         -Cprofile-generate="$(TMPDIR)"/rs-profdata \
-	         -L$(TMPDIR) \
-	         $(COMMON_FLAGS) \
-	         -Clinker=$(CLANG) \
-	         -Clink-arg=-fuse-ld=lld \
-	         -o $(TMPDIR)/rsmain \
-	         ./main.rs
-	$(TMPDIR)/rsmain
-	# Postprocess the profiling data so it can be used by the compiler
-	"$(LLVM_BIN_DIR)"/llvm-profdata merge \
-		-o "$(TMPDIR)"/rs-profdata/merged.profdata \
-		"$(TMPDIR)"/rs-profdata/default_*.profraw
-	$(CLANG) ./clib.c \
-	         -fprofile-use="$(TMPDIR)"/rs-profdata/merged.profdata \
-	         -flto=thin \
-	         -c \
-	         -o $(TMPDIR)/clib.o \
-	         -O3
-	rm "$(TMPDIR)"/libxyz.a
-	(cd $(TMPDIR); $(AR) crus ./libxyz.a ./clib.o)
-	$(RUSTC) -Clinker-plugin-lto=on \
-	         -Cprofile-use="$(TMPDIR)"/rs-profdata/merged.profdata \
-	         -L$(TMPDIR) \
-	         $(COMMON_FLAGS) \
-	         -Clinker=$(CLANG) \
-	         -Clink-arg=-fuse-ld=lld \
-	         -o $(TMPDIR)/rsmain \
-	         ./main.rs
diff --git a/tests/run-make/cross-lang-lto-riscv-abi/rmake.rs b/tests/run-make/cross-lang-lto-riscv-abi/rmake.rs
index 391759ec5f6..92573353a74 100644
--- a/tests/run-make/cross-lang-lto-riscv-abi/rmake.rs
+++ b/tests/run-make/cross-lang-lto-riscv-abi/rmake.rs
@@ -3,8 +3,11 @@
 //@ needs-force-clang-based-tests
 //@ needs-llvm-components riscv
 
-// FIXME(#126180): This test doesn't actually run anywhere, because the only
-// CI job that sets RUSTBUILD_FORCE_CLANG_BASED_TESTS runs very few tests.
+//@ needs-force-clang-based-tests
+// FIXME(#126180): This test can only run on `x86_64-gnu-debug`, because that CI job sets
+// RUSTBUILD_FORCE_CLANG_BASED_TESTS and only runs tests which contain "clang" in their
+// name.
+// However, this test does not run at all as its name does not contain "clang".
 
 use std::path::PathBuf;
 use std::process::{Command, Output};
diff --git a/tests/run-make/wasm-override-linker/rmake.rs b/tests/run-make/wasm-override-linker/rmake.rs
index 01bc08e9901..b04edc18eef 100644
--- a/tests/run-make/wasm-override-linker/rmake.rs
+++ b/tests/run-make/wasm-override-linker/rmake.rs
@@ -2,6 +2,10 @@
 // $ RUSTBUILD_FORCE_CLANG_BASED_TESTS=1 ./x.py test tests/run-make/wasm-override-linker/
 
 //@ needs-force-clang-based-tests
+// FIXME(#126180): This test can only run on `x86_64-gnu-debug`, because that CI job sets
+// RUSTBUILD_FORCE_CLANG_BASED_TESTS and only runs tests which contain "clang" in their
+// name.
+// However, this test does not run at all as its name does not contain "clang".
 
 use run_make_support::{env_var, rustc, target};