Force rlibs to be linked in whole for cdylib and bin

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -2263,7 +2263,7 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
         sess: &'a Session,
         codegen_results: &CodegenResults,
         tmpdir: &Path,
-        crate_type: CrateType,
+        _crate_type: CrateType,
         cnum: CrateNum,
     ) {
         let src = &codegen_results.crate_info.used_crate_source[&cnum];
@@ -2274,13 +2274,15 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
             // whole of each object in our archive into that artifact. This is
             // because a `dylib` can be reused as an intermediate artifact.
             //
+            // NOTE(nbdd0121): Even for non-dylib, we still need to link rlibs
+            // in whole because so that `#[no_mangle]` and `#[used]` items from
+            // upstream need to be root (#47384, #50007).
+            //
             // Note, though, that we don't want to include the whole of a
             // compiler-builtins crate (e.g., compiler-rt) because it'll get
             // repeatedly linked anyway.
             let path = fix_windows_verbatim_for_gcc(path);
-            if crate_type == CrateType::Dylib
-                && codegen_results.crate_info.compiler_builtins != Some(cnum)
-            {
+            if codegen_results.crate_info.compiler_builtins != Some(cnum) {
                 cmd.link_whole_rlib(&path);
             } else {
                 cmd.link_rlib(&path);

src/test/run-make/issue-47384/Makefile

@@ -0,0 +1,12 @@
+-include ../../run-make-fulldeps/tools.mk
+
+# ignore-windows
+# ignore-cross-compile
+
+all: main.rs
+	$(RUSTC) --crate-type lib lib.rs
+	$(RUSTC) --crate-type cdylib -Clink-args="-Tlinker.ld" main.rs
+	# Ensure `#[used]` and `KEEP`-ed section is there
+	objdump -s -j".static" $(TMPDIR)/libmain.so
+	# Ensure `#[no_mangle]` symbol is there
+	nm $(TMPDIR)/libmain.so | $(CGREP) bar

src/test/run-make/issue-47384/lib.rs

@@ -0,0 +1,12 @@
+mod foo {
+    #[link_section = ".rodata.STATIC"]
+    #[used]
+    static STATIC: [u32; 10] = [1; 10];
+}
+
+mod bar {
+    #[no_mangle]
+    extern "C" fn bar() -> i32 {
+        0
+    }
+}

src/test/run-make/issue-47384/linker.ld

@@ -0,0 +1,7 @@
+SECTIONS
+{
+    .static : ALIGN(4)
+    {
+        KEEP(*(.rodata.STATIC));
+    }
+}

src/test/run-make/issue-47384/main.rs

@@ -0,0 +1 @@
+extern crate lib;