Merge pull request #19826 from lnicola/sync-from-rust

minor: Sync from downstream

4 files changed, 120 insertions, 51 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 323538969d7..c5792da2678 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -768,7 +768,7 @@ fn link_natively(
             && cmd.get_args().iter().any(|e| e.to_string_lossy() == "-fuse-ld=lld")
         {
             info!("linker output: {:?}", out);
-            warn!("The linker driver does not support `-fuse-ld=lld`. Retrying without it.");
+            info!("The linker driver does not support `-fuse-ld=lld`. Retrying without it.");
             for arg in cmd.take_args() {
                 if arg.to_string_lossy() != "-fuse-ld=lld" {
                     cmd.arg(arg);
@@ -1053,9 +1053,10 @@ fn link_natively(
                 strip_with_external_utility(sess, stripcmd, out_filename, &["--strip-debug"])
             }
             // Per the manpage, `-x` is the maximum safe strip level for dynamic libraries. (#93988)
-            (Strip::Symbols, CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro) => {
-                strip_with_external_utility(sess, stripcmd, out_filename, &["-x"])
-            }
+            (
+                Strip::Symbols,
+                CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro | CrateType::Sdylib,
+            ) => strip_with_external_utility(sess, stripcmd, out_filename, &["-x"]),
             (Strip::Symbols, _) => {
                 strip_with_external_utility(sess, stripcmd, out_filename, &["--strip-all"])
             }
@@ -1243,8 +1244,10 @@ fn add_sanitizer_libraries(
     // which should be linked to both executables and dynamic libraries.
     // Everywhere else the runtimes are currently distributed as static
     // libraries which should be linked to executables only.
-    if matches!(crate_type, CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro)
-        && !(sess.target.is_like_darwin || sess.target.is_like_msvc)
+    if matches!(
+        crate_type,
+        CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro | CrateType::Sdylib
+    ) && !(sess.target.is_like_darwin || sess.target.is_like_msvc)
     {
         return;
     }
@@ -1938,6 +1941,7 @@ fn add_late_link_args(
     codegen_results: &CodegenResults,
 ) {
     let any_dynamic_crate = crate_type == CrateType::Dylib
+        || crate_type == CrateType::Sdylib
         || codegen_results.crate_info.dependency_formats.iter().any(|(ty, list)| {
             *ty == crate_type && list.iter().any(|&linkage| linkage == Linkage::Dynamic)
         });
diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs
index a09eec5dd74..8fc83908efb 100644
--- a/compiler/rustc_codegen_ssa/src/back/linker.rs
+++ b/compiler/rustc_codegen_ssa/src/back/linker.rs
@@ -816,7 +816,9 @@ impl<'a> Linker for GccLinker<'a> {
                 writeln!(f, "EXPORTS")?;
                 for symbol in symbols {
                     debug!("  _{symbol}");
-                    writeln!(f, "  {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}\"")?;
                 }
             };
             if let Err(error) = res {
@@ -1815,7 +1817,7 @@ pub(crate) fn linked_symbols(
     crate_type: CrateType,
 ) -> Vec<(String, SymbolExportKind)> {
     match crate_type {
-        CrateType::Executable | CrateType::Cdylib | CrateType::Dylib => (),
+        CrateType::Executable | CrateType::Cdylib | CrateType::Dylib | CrateType::Sdylib => (),
         CrateType::Staticlib | CrateType::ProcMacro | CrateType::Rlib => {
             return Vec::new();
         }
diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs
index ebcccf1b97d..ec46c71b0e4 100644
--- a/compiler/rustc_codegen_ssa/src/back/metadata.rs
+++ b/compiler/rustc_codegen_ssa/src/back/metadata.rs
@@ -270,45 +270,61 @@ pub(super) fn elf_os_abi(sess: &Session) -> u8 {
 
 pub(super) fn elf_e_flags(architecture: Architecture, sess: &Session) -> u32 {
     match architecture {
-        Architecture::Mips => {
-            let arch = match sess.target.options.cpu.as_ref() {
-                "mips1" => elf::EF_MIPS_ARCH_1,
-                "mips2" => elf::EF_MIPS_ARCH_2,
+        Architecture::Mips | Architecture::Mips64 | Architecture::Mips64_N32 => {
+            // "N32" indicates an "ILP32" data model on a 64-bit MIPS CPU
+            // like SPARC's "v8+", x86_64's "x32", or the watchOS "arm64_32".
+            let is_32bit = architecture == Architecture::Mips;
+            let mut e_flags = match sess.target.options.cpu.as_ref() {
+                "mips1" if is_32bit => elf::EF_MIPS_ARCH_1,
+                "mips2" if is_32bit => elf::EF_MIPS_ARCH_2,
                 "mips3" => elf::EF_MIPS_ARCH_3,
                 "mips4" => elf::EF_MIPS_ARCH_4,
                 "mips5" => elf::EF_MIPS_ARCH_5,
-                s if s.contains("r6") => elf::EF_MIPS_ARCH_32R6,
-                _ => elf::EF_MIPS_ARCH_32R2,
+                "mips32r2" if is_32bit => elf::EF_MIPS_ARCH_32R2,
+                "mips32r6" if is_32bit => elf::EF_MIPS_ARCH_32R6,
+                "mips64r2" if !is_32bit => elf::EF_MIPS_ARCH_64R2,
+                "mips64r6" if !is_32bit => elf::EF_MIPS_ARCH_64R6,
+                s if s.starts_with("mips32") && !is_32bit => {
+                    sess.dcx().fatal(format!("invalid CPU `{}` for 64-bit MIPS target", s))
+                }
+                s if s.starts_with("mips64") && is_32bit => {
+                    sess.dcx().fatal(format!("invalid CPU `{}` for 32-bit MIPS target", s))
+                }
+                _ if is_32bit => elf::EF_MIPS_ARCH_32R2,
+                _ => elf::EF_MIPS_ARCH_64R2,
             };
 
-            let mut e_flags = elf::EF_MIPS_CPIC | arch;
-
-            // If the ABI is explicitly given, use it or default to O32.
-            match sess.target.options.llvm_abiname.to_lowercase().as_str() {
-                "n32" => e_flags |= elf::EF_MIPS_ABI2,
-                "o32" => e_flags |= elf::EF_MIPS_ABI_O32,
-                _ => e_flags |= elf::EF_MIPS_ABI_O32,
+            // If the ABI is explicitly given, use it, or default to O32 on 32-bit MIPS,
+            // which is the only "true" 32-bit option that LLVM supports.
+            match sess.target.options.llvm_abiname.as_ref() {
+                "o32" if is_32bit => e_flags |= elf::EF_MIPS_ABI_O32,
+                "n32" if !is_32bit => e_flags |= elf::EF_MIPS_ABI2,
+                "n64" if !is_32bit => {}
+                "" if is_32bit => e_flags |= elf::EF_MIPS_ABI_O32,
+                "" => sess.dcx().fatal("LLVM ABI must be specifed for 64-bit MIPS targets"),
+                s if is_32bit => {
+                    sess.dcx().fatal(format!("invalid LLVM ABI `{}` for 32-bit MIPS target", s))
+                }
+                s => sess.dcx().fatal(format!("invalid LLVM ABI `{}` for 64-bit MIPS target", s)),
             };
 
             if sess.target.options.relocation_model != RelocModel::Static {
-                e_flags |= elf::EF_MIPS_PIC;
+                // PIC means position-independent code. CPIC means "calls PIC".
+                // CPIC was mutually exclusive with PIC according to
+                // the SVR4 MIPS ABI https://refspecs.linuxfoundation.org/elf/mipsabi.pdf
+                // and should have only appeared on static objects with dynamically calls.
+                // At some point someone (GCC?) decided to set CPIC even for PIC.
+                // Nowadays various things expect both set on the same object file
+                // and may even error if you mix CPIC and non-CPIC object files,
+                // despite that being the entire point of the CPIC ABI extension!
+                // As we are in Rome, we do as the Romans do.
+                e_flags |= elf::EF_MIPS_PIC | elf::EF_MIPS_CPIC;
             }
             if sess.target.options.cpu.contains("r6") {
                 e_flags |= elf::EF_MIPS_NAN2008;
             }
             e_flags
         }
-        Architecture::Mips64 => {
-            // copied from `mips64el-linux-gnuabi64-gcc foo.c -c`
-            let e_flags = elf::EF_MIPS_CPIC
-                | elf::EF_MIPS_PIC
-                | if sess.target.options.cpu.contains("r6") {
-                    elf::EF_MIPS_ARCH_64R6 | elf::EF_MIPS_NAN2008
-                } else {
-                    elf::EF_MIPS_ARCH_64R2
-                };
-            e_flags
-        }
         Architecture::Riscv32 | Architecture::Riscv64 => {
             // Source: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/079772828bd10933d34121117a222b4cc0ee2200/riscv-elf.adoc
             let mut e_flags: u32 = 0x0;
diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 2bfab1f43bc..96aec9769d2 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -29,7 +29,7 @@ fn crate_export_threshold(crate_type: CrateType) -> SymbolExportLevel {
         CrateType::Executable | CrateType::Staticlib | CrateType::ProcMacro | CrateType::Cdylib => {
             SymbolExportLevel::C
         }
-        CrateType::Rlib | CrateType::Dylib => SymbolExportLevel::Rust,
+        CrateType::Rlib | CrateType::Dylib | CrateType::Sdylib => SymbolExportLevel::Rust,
     }
 }
 
@@ -45,7 +45,7 @@ pub fn crates_export_threshold(crate_types: &[CrateType]) -> SymbolExportLevel {
 }
 
 fn reachable_non_generics_provider(tcx: TyCtxt<'_>, _: LocalCrate) -> DefIdMap<SymbolExportInfo> {
-    if !tcx.sess.opts.output_types.should_codegen() {
+    if !tcx.sess.opts.output_types.should_codegen() && !tcx.is_sdylib_interface_build() {
         return Default::default();
     }
 
@@ -164,11 +164,11 @@ fn is_reachable_non_generic_provider_extern(tcx: TyCtxt<'_>, def_id: DefId) -> b
     tcx.reachable_non_generics(def_id.krate).contains_key(&def_id)
 }
 
-fn exported_symbols_provider_local(
-    tcx: TyCtxt<'_>,
+fn exported_symbols_provider_local<'tcx>(
+    tcx: TyCtxt<'tcx>,
     _: LocalCrate,
-) -> &[(ExportedSymbol<'_>, SymbolExportInfo)] {
-    if !tcx.sess.opts.output_types.should_codegen() {
+) -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportInfo)] {
+    if !tcx.sess.opts.output_types.should_codegen() && !tcx.is_sdylib_interface_build() {
         return &[];
     }
 
@@ -321,6 +321,38 @@ fn exported_symbols_provider_local(
 
         let cgus = tcx.collect_and_partition_mono_items(()).codegen_units;
 
+        // Do not export symbols that cannot be instantiated by downstream crates.
+        let reachable_set = tcx.reachable_set(());
+        let is_local_to_current_crate = |ty: Ty<'_>| {
+            let no_refs = ty.peel_refs();
+            let root_def_id = match no_refs.kind() {
+                ty::Closure(closure, _) => *closure,
+                ty::FnDef(def_id, _) => *def_id,
+                ty::Coroutine(def_id, _) => *def_id,
+                ty::CoroutineClosure(def_id, _) => *def_id,
+                ty::CoroutineWitness(def_id, _) => *def_id,
+                _ => return false,
+            };
+            let Some(root_def_id) = root_def_id.as_local() else {
+                return false;
+            };
+
+            let is_local = !reachable_set.contains(&root_def_id);
+            is_local
+        };
+
+        let is_instantiable_downstream =
+            |did: Option<DefId>, generic_args: GenericArgsRef<'tcx>| {
+                generic_args
+                    .types()
+                    .chain(did.into_iter().map(move |did| tcx.type_of(did).skip_binder()))
+                    .all(move |arg| {
+                        arg.walk().all(|ty| {
+                            ty.as_type().map_or(true, |ty| !is_local_to_current_crate(ty))
+                        })
+                    })
+            };
+
         // The symbols created in this loop are sorted below it
         #[allow(rustc::potential_query_instability)]
         for (mono_item, data) in cgus.iter().flat_map(|cgu| cgu.items().iter()) {
@@ -338,7 +370,7 @@ fn exported_symbols_provider_local(
 
             if !tcx.sess.opts.share_generics() {
                 if tcx.codegen_fn_attrs(mono_item.def_id()).inline
-                    == rustc_attr_parsing::InlineAttr::Never
+                    == rustc_attr_data_structures::InlineAttr::Never
                 {
                     // this is OK, we explicitly allow sharing inline(never) across crates even
                     // without share-generics.
@@ -349,7 +381,12 @@ fn exported_symbols_provider_local(
 
             match *mono_item {
                 MonoItem::Fn(Instance { def: InstanceKind::Item(def), args }) => {
-                    if args.non_erasable_generics().next().is_some() {
+                    let has_generics = args.non_erasable_generics().next().is_some();
+
+                    let should_export =
+                        has_generics && is_instantiable_downstream(Some(def), &args);
+
+                    if should_export {
                         let symbol = ExportedSymbol::Generic(def, args);
                         symbols.push((
                             symbol,
@@ -364,14 +401,24 @@ fn exported_symbols_provider_local(
                 MonoItem::Fn(Instance { def: InstanceKind::DropGlue(_, Some(ty)), args }) => {
                     // A little sanity-check
                     assert_eq!(args.non_erasable_generics().next(), Some(GenericArgKind::Type(ty)));
-                    symbols.push((
-                        ExportedSymbol::DropGlue(ty),
-                        SymbolExportInfo {
-                            level: SymbolExportLevel::Rust,
-                            kind: SymbolExportKind::Text,
-                            used: false,
-                        },
-                    ));
+
+                    // Drop glue did is always going to be non-local outside of libcore, thus we don't need to check it's locality (which includes invoking `type_of` query).
+                    let should_export = match ty.kind() {
+                        ty::Adt(_, args) => is_instantiable_downstream(None, args),
+                        ty::Closure(_, args) => is_instantiable_downstream(None, args),
+                        _ => true,
+                    };
+
+                    if should_export {
+                        symbols.push((
+                            ExportedSymbol::DropGlue(ty),
+                            SymbolExportInfo {
+                                level: SymbolExportLevel::Rust,
+                                kind: SymbolExportKind::Text,
+                                used: false,
+                            },
+                        ));
+                    }
                 }
                 MonoItem::Fn(Instance {
                     def: InstanceKind::AsyncDropGlueCtorShim(_, ty),
@@ -565,7 +612,7 @@ pub(crate) fn symbol_name_for_instance_in_crate<'tcx>(
         ExportedSymbol::Generic(def_id, args) => {
             rustc_symbol_mangling::symbol_name_for_instance_in_crate(
                 tcx,
-                Instance::new(def_id, args),
+                Instance::new_raw(def_id, args),
                 instantiating_crate,
             )
         }
@@ -613,7 +660,7 @@ fn calling_convention_for_symbol<'tcx>(
             None
         }
         ExportedSymbol::NonGeneric(def_id) => Some(Instance::mono(tcx, def_id)),
-        ExportedSymbol::Generic(def_id, args) => Some(Instance::new(def_id, args)),
+        ExportedSymbol::Generic(def_id, args) => Some(Instance::new_raw(def_id, args)),
         // DropGlue always use the Rust calling convention and thus follow the target's default
         // symbol decoration scheme.
         ExportedSymbol::DropGlue(..) => None,