Auto merge of #141024 - jieyouxu:revert-arm64ec, r=wesleywiser

Revert "Fix linking statics on Arm64EC #140176"

This reverts PR #140176.
Unfortunately, this will reopen #138541 (re-breaking the `arm64ec-pc-windows-msvc` target).

Unfortunately, multiple people are [reporting linker warnings related to `__rust_no_alloc_shim_is_unstable`](#140176 (comment)) after this change in `x86_64-pc-windows-msvc` as well. The solution isn't quite clear yet, let's revert to avoid the linker warnings on the Tier 1 MSVC target for now[^timing], and try a reland with a determined solution for `__rust_no_alloc_shim_is_unstable`.

Judging from [people reporting that they are observing this also when bootstrapping w/ stage0 rustc](#140176 (comment)), we may have to cut a new beta and then repoint stage0 against that newer beta?

cc `@dpaoliello` `@wesleywiser`

r? `@wesleywiser` (or compiler)

[^timing]: Note that it's still RustWeek this week, so most team members are N/A.

Author: bors

compiler/rustc_codegen_llvm/src/consts.rs

@@ -364,12 +364,7 @@ impl<'ll> CodegenCx<'ll, '_> {
 
         if !def_id.is_local() {
             let needs_dll_storage_attr = self.use_dll_storage_attrs
-                // If the symbol is a foreign item, then don't automatically apply DLLImport, as
-                // we'll rely on the #[link] attribute instead. BUT, if this is an internal symbol
-                // then it may be generated by the compiler in some crate, so we do need to apply
-                // DLLImport when linking with the MSVC linker.
-                && (!self.tcx.is_foreign_item(def_id)
-                    || (self.sess().target.is_like_msvc && fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL)))
+                && !self.tcx.is_foreign_item(def_id)
                 // Local definitions can never be imported, so we must not apply
                 // the DLLImport annotation.
                 && !dso_local

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -337,12 +337,7 @@ pub(crate) trait Linker {
     fn debuginfo(&mut self, strip: Strip, natvis_debugger_visualizers: &[PathBuf]);
     fn no_crt_objects(&mut self);
     fn no_default_libraries(&mut self);
-    fn export_symbols(
-        &mut self,
-        tmpdir: &Path,
-        crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    );
+    fn export_symbols(&mut self, tmpdir: &Path, crate_type: CrateType, symbols: &[String]);
     fn subsystem(&mut self, subsystem: &str);
     fn linker_plugin_lto(&mut self);
     fn add_eh_frame_header(&mut self) {}
@@ -775,12 +770,7 @@ impl<'a> Linker for GccLinker<'a> {
         }
     }
 
-    fn export_symbols(
-        &mut self,
-        tmpdir: &Path,
-        crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    ) {
+    fn export_symbols(&mut self, tmpdir: &Path, crate_type: CrateType, symbols: &[String]) {
         // Symbol visibility in object files typically takes care of this.
         if crate_type == CrateType::Executable {
             let should_export_executable_symbols =
@@ -809,7 +799,7 @@ impl<'a> Linker for GccLinker<'a> {
             // Write a plain, newline-separated list of symbols
             let res: io::Result<()> = try {
                 let mut f = File::create_buffered(&path)?;
-                for (sym, _) in symbols {
+                for sym in symbols {
                     debug!("  _{sym}");
                     writeln!(f, "_{sym}")?;
                 }
@@ -824,12 +814,11 @@ impl<'a> Linker for GccLinker<'a> {
                 // .def file similar to MSVC one but without LIBRARY section
                 // because LD doesn't like when it's empty
                 writeln!(f, "EXPORTS")?;
-                for (symbol, kind) in symbols {
-                    let kind_marker = if *kind == SymbolExportKind::Data { " DATA" } else { "" };
+                for symbol in symbols {
                     debug!("  _{symbol}");
                     // Quote the name in case it's reserved by linker in some way
                     // (this accounts for names with dots in particular).
-                    writeln!(f, "  \"{symbol}\"{kind_marker}")?;
+                    writeln!(f, "  \"{symbol}\"")?;
                 }
             };
             if let Err(error) = res {
@@ -842,7 +831,7 @@ impl<'a> Linker for GccLinker<'a> {
                 writeln!(f, "{{")?;
                 if !symbols.is_empty() {
                     writeln!(f, "  global:")?;
-                    for (sym, _) in symbols {
+                    for sym in symbols {
                         debug!("    {sym};");
                         writeln!(f, "    {sym};")?;
                     }
@@ -1109,12 +1098,7 @@ impl<'a> Linker for MsvcLinker<'a> {
     // crates. Upstream rlibs may be linked statically to this dynamic library,
     // in which case they may continue to transitively be used and hence need
     // their symbols exported.
-    fn export_symbols(
-        &mut self,
-        tmpdir: &Path,
-        crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    ) {
+    fn export_symbols(&mut self, tmpdir: &Path, crate_type: CrateType, symbols: &[String]) {
         // Symbol visibility takes care of this typically
         if crate_type == CrateType::Executable {
             let should_export_executable_symbols =
@@ -1132,10 +1116,9 @@ impl<'a> Linker for MsvcLinker<'a> {
             // straight to exports.
             writeln!(f, "LIBRARY")?;
             writeln!(f, "EXPORTS")?;
-            for (symbol, kind) in symbols {
-                let kind_marker = if *kind == SymbolExportKind::Data { " DATA" } else { "" };
+            for symbol in symbols {
                 debug!("  _{symbol}");
-                writeln!(f, "  {symbol}{kind_marker}")?;
+                writeln!(f, "  {symbol}")?;
             }
         };
         if let Err(error) = res {
@@ -1276,19 +1259,14 @@ impl<'a> Linker for EmLinker<'a> {
         self.cc_arg("-nodefaultlibs");
     }
 
-    fn export_symbols(
-        &mut self,
-        _tmpdir: &Path,
-        _crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    ) {
+    fn export_symbols(&mut self, _tmpdir: &Path, _crate_type: CrateType, symbols: &[String]) {
         debug!("EXPORTED SYMBOLS:");
 
         self.cc_arg("-s");
 
         let mut arg = OsString::from("EXPORTED_FUNCTIONS=");
         let encoded = serde_json::to_string(
-            &symbols.iter().map(|(sym, _)| "_".to_owned() + sym).collect::<Vec<_>>(),
+            &symbols.iter().map(|sym| "_".to_owned() + sym).collect::<Vec<_>>(),
         )
         .unwrap();
         debug!("{encoded}");
@@ -1450,13 +1428,8 @@ impl<'a> Linker for WasmLd<'a> {
 
     fn no_default_libraries(&mut self) {}
 
-    fn export_symbols(
-        &mut self,
-        _tmpdir: &Path,
-        _crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    ) {
-        for (sym, _) in symbols {
+    fn export_symbols(&mut self, _tmpdir: &Path, _crate_type: CrateType, symbols: &[String]) {
+        for sym in symbols {
             self.link_args(&["--export", sym]);
         }
 
@@ -1590,7 +1563,7 @@ impl<'a> Linker for L4Bender<'a> {
         self.cc_arg("-nostdlib");
     }
 
-    fn export_symbols(&mut self, _: &Path, _: CrateType, _: &[(String, SymbolExportKind)]) {
+    fn export_symbols(&mut self, _: &Path, _: CrateType, _: &[String]) {
         // ToDo, not implemented, copy from GCC
         self.sess.dcx().emit_warn(errors::L4BenderExportingSymbolsUnimplemented);
     }
@@ -1747,17 +1720,12 @@ impl<'a> Linker for AixLinker<'a> {
 
     fn no_default_libraries(&mut self) {}
 
-    fn export_symbols(
-        &mut self,
-        tmpdir: &Path,
-        _crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    ) {
+    fn export_symbols(&mut self, tmpdir: &Path, _crate_type: CrateType, symbols: &[String]) {
         let path = tmpdir.join("list.exp");
         let res: io::Result<()> = try {
             let mut f = File::create_buffered(&path)?;
             // FIXME: use llvm-nm to generate export list.
-            for (symbol, _) in symbols {
+            for symbol in symbols {
                 debug!("  _{symbol}");
                 writeln!(f, "  {symbol}")?;
             }
@@ -1801,12 +1769,9 @@ fn for_each_exported_symbols_include_dep<'tcx>(
     }
 }
 
-pub(crate) fn exported_symbols(
-    tcx: TyCtxt<'_>,
-    crate_type: CrateType,
-) -> Vec<(String, SymbolExportKind)> {
+pub(crate) fn exported_symbols(tcx: TyCtxt<'_>, crate_type: CrateType) -> Vec<String> {
     if let Some(ref exports) = tcx.sess.target.override_export_symbols {
-        return exports.iter().map(|name| (name.to_string(), SymbolExportKind::Text)).collect();
+        return exports.iter().map(ToString::to_string).collect();
     }
 
     if let CrateType::ProcMacro = crate_type {
@@ -1816,29 +1781,25 @@ pub(crate) fn exported_symbols(
     }
 }
 
-fn exported_symbols_for_non_proc_macro(
-    tcx: TyCtxt<'_>,
-    crate_type: CrateType,
-) -> Vec<(String, SymbolExportKind)> {
+fn exported_symbols_for_non_proc_macro(tcx: TyCtxt<'_>, crate_type: CrateType) -> Vec<String> {
     let mut symbols = Vec::new();
     let export_threshold = symbol_export::crates_export_threshold(&[crate_type]);
     for_each_exported_symbols_include_dep(tcx, crate_type, |symbol, info, cnum| {
         // Do not export mangled symbols from cdylibs and don't attempt to export compiler-builtins
         // from any cdylib. The latter doesn't work anyway as we use hidden visibility for
         // compiler-builtins. Most linkers silently ignore it, but ld64 gives a warning.
         if info.level.is_below_threshold(export_threshold) && !tcx.is_compiler_builtins(cnum) {
-            symbols.push((
-                symbol_export::exporting_symbol_name_for_instance_in_crate(tcx, symbol, cnum),
-                info.kind,
+            symbols.push(symbol_export::exporting_symbol_name_for_instance_in_crate(
+                tcx, symbol, cnum,
             ));
-            symbol_export::extend_exported_symbols(&mut symbols, tcx, symbol, info, cnum);
+            symbol_export::extend_exported_symbols(&mut symbols, tcx, symbol, cnum);
         }
     });
 
     symbols
 }
 
-fn exported_symbols_for_proc_macro_crate(tcx: TyCtxt<'_>) -> Vec<(String, SymbolExportKind)> {
+fn exported_symbols_for_proc_macro_crate(tcx: TyCtxt<'_>) -> Vec<String> {
     // `exported_symbols` will be empty when !should_codegen.
     if !tcx.sess.opts.output_types.should_codegen() {
         return Vec::new();
@@ -1848,10 +1809,7 @@ fn exported_symbols_for_proc_macro_crate(tcx: TyCtxt<'_>) -> Vec<(String, Symbol
     let proc_macro_decls_name = tcx.sess.generate_proc_macro_decls_symbol(stable_crate_id);
     let metadata_symbol_name = exported_symbols::metadata_symbol_name(tcx);
 
-    vec![
-        (proc_macro_decls_name, SymbolExportKind::Text),
-        (metadata_symbol_name, SymbolExportKind::Text),
-    ]
+    vec![proc_macro_decls_name, metadata_symbol_name]
 }
 
 pub(crate) fn linked_symbols(
@@ -1873,9 +1831,7 @@ pub(crate) fn linked_symbols(
             || info.used
         {
             symbols.push((
-                symbol_export::linking_symbol_name_for_instance_in_crate(
-                    tcx, symbol, info.kind, cnum,
-                ),
+                symbol_export::linking_symbol_name_for_instance_in_crate(tcx, symbol, cnum),
                 info.kind,
             ));
         }
@@ -1950,13 +1906,7 @@ impl<'a> Linker for PtxLinker<'a> {
 
     fn ehcont_guard(&mut self) {}
 
-    fn export_symbols(
-        &mut self,
-        _tmpdir: &Path,
-        _crate_type: CrateType,
-        _symbols: &[(String, SymbolExportKind)],
-    ) {
-    }
+    fn export_symbols(&mut self, _tmpdir: &Path, _crate_type: CrateType, _symbols: &[String]) {}
 
     fn subsystem(&mut self, _subsystem: &str) {}
 
@@ -2025,15 +1975,10 @@ impl<'a> Linker for LlbcLinker<'a> {
 
     fn ehcont_guard(&mut self) {}
 
-    fn export_symbols(
-        &mut self,
-        _tmpdir: &Path,
-        _crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    ) {
+    fn export_symbols(&mut self, _tmpdir: &Path, _crate_type: CrateType, symbols: &[String]) {
         match _crate_type {
             CrateType::Cdylib => {
-                for (sym, _) in symbols {
+                for sym in symbols {
                     self.link_args(&["--export-symbol", sym]);
                 }
             }
@@ -2107,16 +2052,11 @@ impl<'a> Linker for BpfLinker<'a> {
 
     fn ehcont_guard(&mut self) {}
 
-    fn export_symbols(
-        &mut self,
-        tmpdir: &Path,
-        _crate_type: CrateType,
-        symbols: &[(String, SymbolExportKind)],
-    ) {
+    fn export_symbols(&mut self, tmpdir: &Path, _crate_type: CrateType, symbols: &[String]) {
         let path = tmpdir.join("symbols");
         let res: io::Result<()> = try {
             let mut f = File::create_buffered(&path)?;
-            for (sym, _) in symbols {
+            for sym in symbols {
                 writeln!(f, "{sym}")?;
             }
         };

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -692,7 +692,6 @@ fn calling_convention_for_symbol<'tcx>(
 pub(crate) fn linking_symbol_name_for_instance_in_crate<'tcx>(
     tcx: TyCtxt<'tcx>,
     symbol: ExportedSymbol<'tcx>,
-    export_kind: SymbolExportKind,
     instantiating_crate: CrateNum,
 ) -> String {
     let mut undecorated = symbol_name_for_instance_in_crate(tcx, symbol, instantiating_crate);
@@ -713,9 +712,8 @@ pub(crate) fn linking_symbol_name_for_instance_in_crate<'tcx>(
     let prefix = match &target.arch[..] {
         "x86" => Some('_'),
         "x86_64" => None,
-        // Only functions are decorated for arm64ec.
-        "arm64ec" if export_kind == SymbolExportKind::Text => Some('#'),
-        // Only x86/64 and arm64ec use symbol decorations.
+        "arm64ec" => Some('#'),
+        // Only x86/64 use symbol decorations.
         _ => return undecorated,
     };
 
@@ -755,10 +753,9 @@ pub(crate) fn exporting_symbol_name_for_instance_in_crate<'tcx>(
 /// Add it to the symbols list for all kernel functions, so that it is exported in the linked
 /// object.
 pub(crate) fn extend_exported_symbols<'tcx>(
-    symbols: &mut Vec<(String, SymbolExportKind)>,
+    symbols: &mut Vec<String>,
     tcx: TyCtxt<'tcx>,
     symbol: ExportedSymbol<'tcx>,
-    info: SymbolExportInfo,
     instantiating_crate: CrateNum,
 ) {
     let (conv, _) = calling_convention_for_symbol(tcx, symbol);
@@ -770,7 +767,7 @@ pub(crate) fn extend_exported_symbols<'tcx>(
     let undecorated = symbol_name_for_instance_in_crate(tcx, symbol, instantiating_crate);
 
     // Add the symbol for the kernel descriptor (with .kd suffix)
-    symbols.push((format!("{undecorated}.kd"), info.kind));
+    symbols.push(format!("{undecorated}.kd"));
 }
 
 fn maybe_emutls_symbol_name<'tcx>(