use --dynamic-list for exporting executable symbols

Author: usamoi

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -835,6 +835,22 @@ impl<'a> Linker for GccLinker<'a> {
             if let Err(error) = res {
                 self.sess.dcx().emit_fatal(errors::LibDefWriteFailure { error });
             }
+        } else if crate_type == CrateType::Executable {
+            // Write an LD version script
+            let res: io::Result<()> = try {
+                let mut f = File::create_buffered(&path)?;
+                writeln!(f, "{{")?;
+                if !symbols.is_empty() {
+                    for (sym, _) in symbols {
+                        debug!("  {sym};");
+                        writeln!(f, "  {sym};")?;
+                    }
+                }
+                writeln!(f, "}};")?;
+            };
+            if let Err(error) = res {
+                self.sess.dcx().emit_fatal(errors::VersionScriptWriteFailure { error });
+            }
         } else {
             // Write an LD version script
             let res: io::Result<()> = try {
@@ -860,6 +876,8 @@ impl<'a> Linker for GccLinker<'a> {
             self.link_arg("-M").link_arg(path);
         } else if is_windows {
             self.link_arg(path);
+        } else if crate_type == CrateType::Executable {
+            self.link_arg("--dynamic-list").link_arg(path);
         } else {
             let mut arg = OsString::from("--version-script=");
             arg.push(path);

tests/ui/linking/export-executable-symbols.rs

@@ -0,0 +1,29 @@
+//@ run-pass
+//@ only-linux
+//@ compile-flags: -Zexport-executable-symbols
+//@ edition: 2024
+
+// Regression test for <https://github.com/rust-lang/rust/issues/101610>.
+
+#![feature(rustc_private)]
+
+extern crate libc;
+
+#[unsafe(no_mangle)]
+fn hack() -> u64 {
+    998244353
+}
+
+fn main() {
+    unsafe {
+        let handle = libc::dlopen(std::ptr::null(), libc::RTLD_NOW);
+        let ptr = libc::dlsym(handle, c"hack".as_ptr());
+        let ptr: Option<unsafe fn() -> u64> = std::mem::transmute(ptr);
+        if let Some(f) = ptr {
+            assert!(f() == 998244353);
+            println!("symbol `hack` is found successfully");
+        } else {
+            panic!("symbol `hack` is not found");
+        }
+    }
+}