Rollup of 8 pull requests

compiler/rustc_codegen_gcc/src/archive.rs

@@ -2,6 +2,7 @@ use std::path::Path;
 
 use rustc_codegen_ssa::back::archive::{
     ArArchiveBuilder, ArchiveBuilder, ArchiveBuilderBuilder, DEFAULT_OBJECT_READER,
+    ImportLibraryItem,
 };
 use rustc_session::Session;
 
@@ -16,7 +17,7 @@ impl ArchiveBuilderBuilder for ArArchiveBuilderBuilder {
         &self,
         _sess: &Session,
         _lib_name: &str,
-        _import_name_and_ordinal_vector: Vec<(String, Option<u16>)>,
+        _items: Vec<ImportLibraryItem>,
         _output_path: &Path,
     ) {
         unimplemented!("creating dll imports is not yet supported");

compiler/rustc_codegen_llvm/src/callee.rs

@@ -44,6 +44,22 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
         let llfn = if tcx.sess.target.arch == "x86"
             && let Some(dllimport) = crate::common::get_dllimport(tcx, instance_def_id, sym)
         {
+            // When calling functions in generated import libraries, MSVC needs
+            // the fully decorated name (as would have been in the declaring
+            // object file), but MinGW wants the name as exported (as would be
+            // in the def file) which may be missing decorations.
+            let mingw_gnu_toolchain = common::is_mingw_gnu_toolchain(&tcx.sess.target);
+            let llfn = cx.declare_fn(
+                &common::i686_decorated_name(
+                    dllimport,
+                    mingw_gnu_toolchain,
+                    true,
+                    !mingw_gnu_toolchain,
+                ),
+                fn_abi,
+                Some(instance),
+            );
+
             // Fix for https://github.com/rust-lang/rust/issues/104453
             // On x86 Windows, LLVM uses 'L' as the prefix for any private
             // global symbols, so when we create an undecorated function symbol
@@ -55,15 +71,6 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
             // LLVM will prefix the name with `__imp_`. Ideally, we'd like the
             // existing logic below to set the Storage Class, but it has an
             // exemption for MinGW for backwards compatibility.
-            let llfn = cx.declare_fn(
-                &common::i686_decorated_name(
-                    dllimport,
-                    common::is_mingw_gnu_toolchain(&tcx.sess.target),
-                    true,
-                ),
-                fn_abi,
-                Some(instance),
-            );
             unsafe {
                 llvm::LLVMSetDLLStorageClass(llfn, llvm::DLLStorageClass::DllImport);
             }

compiler/rustc_codegen_llvm/src/consts.rs

@@ -194,16 +194,10 @@ fn check_and_apply_linkage<'ll, 'tcx>(
         unsafe { llvm::LLVMSetInitializer(g2, g1) };
         g2
     } else if cx.tcx.sess.target.arch == "x86"
+        && common::is_mingw_gnu_toolchain(&cx.tcx.sess.target)
         && let Some(dllimport) = crate::common::get_dllimport(cx.tcx, def_id, sym)
     {
-        cx.declare_global(
-            &common::i686_decorated_name(
-                dllimport,
-                common::is_mingw_gnu_toolchain(&cx.tcx.sess.target),
-                true,
-            ),
-            llty,
-        )
+        cx.declare_global(&common::i686_decorated_name(dllimport, true, true, false), llty)
     } else {
         // Generate an external declaration.
         // FIXME(nagisa): investigate whether it can be changed into define_global

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -26,6 +26,35 @@ use crate::errors::{
     DlltoolFailImportLibrary, ErrorCallingDllTool, ErrorCreatingImportLibrary, ErrorWritingDEFFile,
 };
 
+/// An item to be included in an import library.
+/// This is a slimmed down version of `COFFShortExport` from `ar-archive-writer`.
+pub struct ImportLibraryItem {
+    /// The name to be exported.
+    pub name: String,
+    /// The ordinal to be exported, if any.
+    pub ordinal: Option<u16>,
+    /// The original, decorated name if `name` is not decorated.
+    pub symbol_name: Option<String>,
+    /// True if this is a data export, false if it is a function export.
+    pub is_data: bool,
+}
+
+impl From<ImportLibraryItem> for COFFShortExport {
+    fn from(item: ImportLibraryItem) -> Self {
+        COFFShortExport {
+            name: item.name,
+            ext_name: None,
+            symbol_name: item.symbol_name,
+            alias_target: None,
+            ordinal: item.ordinal.unwrap_or(0),
+            noname: item.ordinal.is_some(),
+            data: item.is_data,
+            private: false,
+            constant: false,
+        }
+    }
+}
+
 pub trait ArchiveBuilderBuilder {
     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a>;
 
@@ -38,7 +67,7 @@ pub trait ArchiveBuilderBuilder {
         &self,
         sess: &Session,
         lib_name: &str,
-        import_name_and_ordinal_vector: Vec<(String, Option<u16>)>,
+        items: Vec<ImportLibraryItem>,
         output_path: &Path,
     ) {
         if common::is_mingw_gnu_toolchain(&sess.target) {
@@ -47,21 +76,16 @@ pub trait ArchiveBuilderBuilder {
             // that loaded but crashed with an AV upon calling one of the imported
             // functions. Therefore, use binutils to create the import library instead,
             // by writing a .DEF file to the temp dir and calling binutils's dlltool.
-            create_mingw_dll_import_lib(
-                sess,
-                lib_name,
-                import_name_and_ordinal_vector,
-                output_path,
-            );
+            create_mingw_dll_import_lib(sess, lib_name, items, output_path);
         } else {
             trace!("creating import library");
             trace!("  dll_name {:#?}", lib_name);
             trace!("  output_path {}", output_path.display());
             trace!(
                 "  import names: {}",
-                import_name_and_ordinal_vector
+                items
                     .iter()
-                    .map(|(name, _ordinal)| name.clone())
+                    .map(|ImportLibraryItem { name, .. }| name.clone())
                     .collect::<Vec<_>>()
                     .join(", "),
             );
@@ -79,20 +103,7 @@ pub trait ArchiveBuilderBuilder {
                     .emit_fatal(ErrorCreatingImportLibrary { lib_name, error: error.to_string() }),
             };
 
-            let exports = import_name_and_ordinal_vector
-                .iter()
-                .map(|(name, ordinal)| COFFShortExport {
-                    name: name.to_string(),
-                    ext_name: None,
-                    symbol_name: None,
-                    alias_target: None,
-                    ordinal: ordinal.unwrap_or(0),
-                    noname: ordinal.is_some(),
-                    data: false,
-                    private: false,
-                    constant: false,
-                })
-                .collect::<Vec<_>>();
+            let exports = items.into_iter().map(Into::into).collect::<Vec<_>>();
             let machine = match &*sess.target.arch {
                 "x86_64" => MachineTypes::AMD64,
                 "x86" => MachineTypes::I386,
@@ -160,16 +171,16 @@ pub trait ArchiveBuilderBuilder {
 fn create_mingw_dll_import_lib(
     sess: &Session,
     lib_name: &str,
-    import_name_and_ordinal_vector: Vec<(String, Option<u16>)>,
+    items: Vec<ImportLibraryItem>,
     output_path: &Path,
 ) {
     let def_file_path = output_path.with_extension("def");
 
     let def_file_content = format!(
         "EXPORTS\n{}",
-        import_name_and_ordinal_vector
+        items
             .into_iter()
-            .map(|(name, ordinal)| {
+            .map(|ImportLibraryItem { name, ordinal, .. }| {
                 match ordinal {
                     Some(n) => format!("{name} @{n} NONAME"),
                     None => name,

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -45,7 +45,7 @@ use rustc_target::spec::{
 use tempfile::Builder as TempFileBuilder;
 use tracing::{debug, info, warn};
 
-use super::archive::{ArchiveBuilder, ArchiveBuilderBuilder};
+use super::archive::{ArchiveBuilder, ArchiveBuilderBuilder, ImportLibraryItem};
 use super::command::Command;
 use super::linker::{self, Linker};
 use super::metadata::{MetadataPosition, create_wrapper_file};
@@ -495,24 +495,43 @@ fn create_dll_import_libs<'a>(
 
             let mingw_gnu_toolchain = common::is_mingw_gnu_toolchain(&sess.target);
 
-            let import_name_and_ordinal_vector: Vec<(String, Option<u16>)> = raw_dylib_imports
+            let items: Vec<ImportLibraryItem> = raw_dylib_imports
                 .iter()
                 .map(|import: &DllImport| {
                     if sess.target.arch == "x86" {
-                        (
-                            common::i686_decorated_name(import, mingw_gnu_toolchain, false),
-                            import.ordinal(),
-                        )
+                        ImportLibraryItem {
+                            name: common::i686_decorated_name(
+                                import,
+                                mingw_gnu_toolchain,
+                                false,
+                                false,
+                            ),
+                            ordinal: import.ordinal(),
+                            symbol_name: import.is_missing_decorations().then(|| {
+                                common::i686_decorated_name(
+                                    import,
+                                    mingw_gnu_toolchain,
+                                    false,
+                                    true,
+                                )
+                            }),
+                            is_data: !import.is_fn,
+                        }
                     } else {
-                        (import.name.to_string(), import.ordinal())
+                        ImportLibraryItem {
+                            name: import.name.to_string(),
+                            ordinal: import.ordinal(),
+                            symbol_name: None,
+                            is_data: !import.is_fn,
+                        }
                     }
                 })
                 .collect();
 
             archive_builder_builder.create_dll_import_lib(
                 sess,
                 &raw_dylib_name,
-                import_name_and_ordinal_vector,
+                items,
                 &output_path,
             );
 

compiler/rustc_codegen_ssa/src/common.rs

@@ -187,12 +187,15 @@ pub fn i686_decorated_name(
     dll_import: &DllImport,
     mingw: bool,
     disable_name_mangling: bool,
+    force_fully_decorated: bool,
 ) -> String {
     let name = dll_import.name.as_str();
 
-    let (add_prefix, add_suffix) = match dll_import.import_name_type {
-        Some(PeImportNameType::NoPrefix) => (false, true),
-        Some(PeImportNameType::Undecorated) => (false, false),
+    let (add_prefix, add_suffix) = match (force_fully_decorated, dll_import.import_name_type) {
+        // No prefix is a bit weird, in that LLVM/ar_archive_writer won't emit it, so we will
+        // ignore `force_fully_decorated` and always partially decorate it.
+        (_, Some(PeImportNameType::NoPrefix)) => (false, true),
+        (false, Some(PeImportNameType::Undecorated)) => (false, false),
         _ => (true, true),
     };