Rollup merge of #149772 - dianqk:no-builtins-linker-plugin-lto, r=jieyouxu

test: Add a test for 146133

This is a test without using `-Zbuild-std` for #146133. There is another test using `-Zbuild-std`: rust-lang/cargo#16277.

Even if a crate is marked as `#![no_builtins]`, we can still generate bitcode for rlib, but we cannot emit bitcode to the linker in rustc's LTO.

Author: matthiaskrgr

tests/run-make/no-builtins-linker-plugin-lto/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    no_builtins::foo();
+}

tests/run-make/no-builtins-linker-plugin-lto/no_builtins.rs

@@ -0,0 +1,4 @@
+#![no_builtins]
+
+#[inline(never)]
+pub fn foo() {}

tests/run-make/no-builtins-linker-plugin-lto/rmake.rs

@@ -0,0 +1,53 @@
+//@ only-x86_64-unknown-linux-gnu
+
+use std::fs;
+use std::path::Path;
+
+use run_make_support::{cwd, has_extension, llvm_ar, llvm_bcanalyzer, rust_lib_name, rustc};
+
+// A regression test for #146133.
+
+fn main() {
+    // Compile a `#![no_builtins]` rlib crate with `-Clinker-plugin-lto`.
+    // It is acceptable to generate bitcode for rlib, so there is no need to check something.
+    rustc().input("no_builtins.rs").crate_type("rlib").linker_plugin_lto("on").run();
+
+    // Checks that rustc's LTO doesn't emit any bitcode to the linker.
+    let stdout = rustc()
+        .input("main.rs")
+        .extern_("no_builtins", rust_lib_name("no_builtins"))
+        .lto("thin")
+        .print("link-args")
+        .arg("-Csave-temps")
+        .arg("-Clinker-features=-lld")
+        .run()
+        .stdout_utf8();
+    for object in stdout
+        .split_whitespace()
+        .map(|s| s.trim_matches('"'))
+        .filter(|path| has_extension(path, "rlib") || has_extension(path, "o"))
+    {
+        let object_path = if !fs::exists(object).unwrap() {
+            cwd().join(object)
+        } else {
+            Path::new(object).to_path_buf()
+        };
+        if has_extension(object, "rlib") {
+            let ar_stdout = llvm_ar().arg("t").arg(&object_path).run().stdout_utf8();
+            llvm_ar().extract().arg(&object_path).run();
+            for object in ar_stdout.split_whitespace().filter(|o| has_extension(o, "o")) {
+                let object_path = cwd().join(object);
+                not_bitcode(&object_path);
+            }
+        } else {
+            not_bitcode(&object_path);
+        }
+    }
+}
+
+fn not_bitcode(object: &Path) {
+    llvm_bcanalyzer()
+        .input(object)
+        .run_fail()
+        .assert_stderr_contains("llvm-bcanalyzer: Invalid record at top-level");
+}