Merge from rust-lang/rust

4 files changed, 256 insertions, 33 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 892dfb91201..e7b1c63a822 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -40,7 +40,7 @@ use rustc_target::spec::crt_objects::CrtObjects;
 use rustc_target::spec::{
     Cc, LinkOutputKind, LinkSelfContainedComponents, LinkSelfContainedDefault, LinkerFeatures,
     LinkerFlavor, LinkerFlavorCli, Lld, PanicStrategy, RelocModel, RelroLevel, SanitizerSet,
-    SplitDebuginfo,
+    SplitDebuginfo, current_apple_deployment_target,
 };
 use tempfile::Builder as TempFileBuilder;
 use tracing::{debug, info, warn};
@@ -1087,16 +1087,17 @@ fn link_natively(
     let strip = sess.opts.cg.strip;
 
     if sess.target.is_like_osx {
+        let stripcmd = "/usr/bin/strip";
         match (strip, crate_type) {
             (Strip::Debuginfo, _) => {
-                strip_symbols_with_external_utility(sess, "strip", out_filename, Some("-S"))
+                strip_symbols_with_external_utility(sess, stripcmd, out_filename, Some("-S"))
             }
             // Per the manpage, `-x` is the maximum safe strip level for dynamic libraries. (#93988)
             (Strip::Symbols, CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro) => {
-                strip_symbols_with_external_utility(sess, "strip", out_filename, Some("-x"))
+                strip_symbols_with_external_utility(sess, stripcmd, out_filename, Some("-x"))
             }
             (Strip::Symbols, _) => {
-                strip_symbols_with_external_utility(sess, "strip", out_filename, None)
+                strip_symbols_with_external_utility(sess, stripcmd, out_filename, None)
             }
             (Strip::None, _) => {}
         }
@@ -2404,6 +2405,8 @@ fn add_order_independent_options(
     // Take care of the flavors and CLI options requesting the `lld` linker.
     add_lld_args(cmd, sess, flavor, self_contained_components);
 
+    add_apple_link_args(cmd, sess, flavor);
+
     let apple_sdk_root = add_apple_sdk(cmd, sess, flavor);
 
     add_link_script(cmd, sess, tmpdir, crate_type);
@@ -2487,7 +2490,7 @@ fn add_order_independent_options(
         }
     }
 
-    cmd.set_output_kind(link_output_kind, out_filename);
+    cmd.set_output_kind(link_output_kind, crate_type, out_filename);
 
     add_relro_args(cmd, sess);
 
@@ -2956,6 +2959,169 @@ pub(crate) fn are_upstream_rust_objects_already_included(sess: &Session) -> bool
     }
 }
 
+/// We need to communicate five things to the linker on Apple/Darwin targets:
+/// - The architecture.
+/// - The operating system (and that it's an Apple platform).
+/// - The environment / ABI.
+/// - The deployment target.
+/// - The SDK version.
+fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) {
+    if !sess.target.is_like_osx {
+        return;
+    }
+    let LinkerFlavor::Darwin(cc, _) = flavor else {
+        return;
+    };
+
+    // `sess.target.arch` (`target_arch`) is not detailed enough.
+    let llvm_arch = sess.target.llvm_target.split_once('-').expect("LLVM target must have arch").0;
+    let target_os = &*sess.target.os;
+    let target_abi = &*sess.target.abi;
+
+    // The architecture name to forward to the linker.
+    //
+    // Supported architecture names can be found in the source:
+    // https://github.com/apple-oss-distributions/ld64/blob/ld64-951.9/src/abstraction/MachOFileAbstraction.hpp#L578-L648
+    //
+    // Intentially verbose to ensure that the list always matches correctly
+    // with the list in the source above.
+    let ld64_arch = match llvm_arch {
+        "armv7k" => "armv7k",
+        "armv7s" => "armv7s",
+        "arm64" => "arm64",
+        "arm64e" => "arm64e",
+        "arm64_32" => "arm64_32",
+        // ld64 doesn't understand i686, so fall back to i386 instead.
+        //
+        // Same story when linking with cc, since that ends up invoking ld64.
+        "i386" | "i686" => "i386",
+        "x86_64" => "x86_64",
+        "x86_64h" => "x86_64h",
+        _ => bug!("unsupported architecture in Apple target: {}", sess.target.llvm_target),
+    };
+
+    if cc == Cc::No {
+        // From the man page for ld64 (`man ld`):
+        // > The linker accepts universal (multiple-architecture) input files,
+        // > but always creates a "thin" (single-architecture), standard
+        // > Mach-O output file. The architecture for the output file is
+        // > specified using the -arch option.
+        //
+        // The linker has heuristics to determine the desired architecture,
+        // but to be safe, and to avoid a warning, we set the architecture
+        // explicitly.
+        cmd.link_args(&["-arch", ld64_arch]);
+
+        // Man page says that ld64 supports the following platform names:
+        // > - macos
+        // > - ios
+        // > - tvos
+        // > - watchos
+        // > - bridgeos
+        // > - visionos
+        // > - xros
+        // > - mac-catalyst
+        // > - ios-simulator
+        // > - tvos-simulator
+        // > - watchos-simulator
+        // > - visionos-simulator
+        // > - xros-simulator
+        // > - driverkit
+        let platform_name = match (target_os, target_abi) {
+            (os, "") => os,
+            ("ios", "macabi") => "mac-catalyst",
+            ("ios", "sim") => "ios-simulator",
+            ("tvos", "sim") => "tvos-simulator",
+            ("watchos", "sim") => "watchos-simulator",
+            ("visionos", "sim") => "visionos-simulator",
+            _ => bug!("invalid OS/ABI combination for Apple target: {target_os}, {target_abi}"),
+        };
+
+        let (major, minor, patch) = current_apple_deployment_target(&sess.target);
+        let min_version = format!("{major}.{minor}.{patch}");
+
+        // The SDK version is used at runtime when compiling with a newer SDK / version of Xcode:
+        // - By dyld to give extra warnings and errors, see e.g.:
+        //   <https://github.com/apple-oss-distributions/dyld/blob/dyld-1165.3/common/MachOFile.cpp#L3029>
+        //   <https://github.com/apple-oss-distributions/dyld/blob/dyld-1165.3/common/MachOFile.cpp#L3738-L3857>
+        // - By system frameworks to change certain behaviour. For example, the default value of
+        //   `-[NSView wantsBestResolutionOpenGLSurface]` is `YES` when the SDK version is >= 10.15.
+        //   <https://developer.apple.com/documentation/appkit/nsview/1414938-wantsbestresolutionopenglsurface?language=objc>
+        //
+        // We do not currently know the actual SDK version though, so we have a few options:
+        // 1. Use the minimum version supported by rustc.
+        // 2. Use the same as the deployment target.
+        // 3. Use an arbitary recent version.
+        // 4. Omit the version.
+        //
+        // The first option is too low / too conservative, and means that users will not get the
+        // same behaviour from a binary compiled with rustc as with one compiled by clang.
+        //
+        // The second option is similarly conservative, and also wrong since if the user specified a
+        // higher deployment target than the SDK they're compiling/linking with, the runtime might
+        // make invalid assumptions about the capabilities of the binary.
+        //
+        // The third option requires that `rustc` is periodically kept up to date with Apple's SDK
+        // version, and is also wrong for similar reasons as above.
+        //
+        // The fourth option is bad because while `ld`, `otool`, `vtool` and such understand it to
+        // mean "absent" or `n/a`, dyld doesn't actually understand it, and will end up interpreting
+        // it as 0.0, which is again too low/conservative.
+        //
+        // Currently, we lie about the SDK version, and choose the second option.
+        //
+        // FIXME(madsmtm): Parse the SDK version from the SDK root instead.
+        // <https://github.com/rust-lang/rust/issues/129432>
+        let sdk_version = &*min_version;
+
+        // From the man page for ld64 (`man ld`):
+        // > This is set to indicate the platform, oldest supported version of
+        // > that platform that output is to be used on, and the SDK that the
+        // > output was built against.
+        //
+        // Like with `-arch`, the linker can figure out the platform versions
+        // itself from the binaries being linked, but to be safe, we specify
+        // the desired versions here explicitly.
+        cmd.link_args(&["-platform_version", platform_name, &*min_version, sdk_version]);
+    } else {
+        // cc == Cc::Yes
+        //
+        // We'd _like_ to use `-target` everywhere, since that can uniquely
+        // communicate all the required details except for the SDK version
+        // (which is read by Clang itself from the SDKROOT), but that doesn't
+        // work on GCC, and since we don't know whether the `cc` compiler is
+        // Clang, GCC, or something else, we fall back to other options that
+        // also work on GCC when compiling for macOS.
+        //
+        // Targets other than macOS are ill-supported by GCC (it doesn't even
+        // support e.g. `-miphoneos-version-min`), so in those cases we can
+        // fairly safely use `-target`. See also the following, where it is
+        // made explicit that the recommendation by LLVM developers is to use
+        // `-target`: <https://github.com/llvm/llvm-project/issues/88271>
+        if target_os == "macos" {
+            // `-arch` communicates the architecture.
+            //
+            // CC forwards the `-arch` to the linker, so we use the same value
+            // here intentionally.
+            cmd.cc_args(&["-arch", ld64_arch]);
+
+            // The presence of `-mmacosx-version-min` makes CC default to
+            // macOS, and it sets the deployment target.
+            let (major, minor, patch) = current_apple_deployment_target(&sess.target);
+            // Intentionally pass this as a single argument, Clang doesn't
+            // seem to like it otherwise.
+            cmd.cc_arg(&format!("-mmacosx-version-min={major}.{minor}.{patch}"));
+
+            // macOS has no environment, so with these two, we've told CC the
+            // four desired parameters.
+            //
+            // We avoid `-m32`/`-m64`, as this is already encoded by `-arch`.
+        } else {
+            cmd.cc_args(&["-target", &sess.target.llvm_target]);
+        }
+    }
+}
+
 fn add_apple_sdk(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) -> Option<PathBuf> {
     let arch = &sess.target.arch;
     let os = &sess.target.os;
diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs
index 84817e19844..3f3d305da01 100644
--- a/compiler/rustc_codegen_ssa/src/back/linker.rs
+++ b/compiler/rustc_codegen_ssa/src/back/linker.rs
@@ -1,9 +1,8 @@
 use std::ffi::{OsStr, OsString};
 use std::fs::{self, File};
 use std::io::prelude::*;
-use std::io::{self, BufWriter};
 use std::path::{Path, PathBuf};
-use std::{env, iter, mem, str};
+use std::{env, io, iter, mem, str};
 
 use cc::windows_registry;
 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
@@ -276,7 +275,12 @@ pub(crate) trait Linker {
     fn is_cc(&self) -> bool {
         false
     }
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path);
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        crate_type: CrateType,
+        out_filename: &Path,
+    );
     fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) {
         bug!("dylib linked with unsupported linker")
     }
@@ -397,7 +401,7 @@ impl<'a> GccLinker<'a> {
         ]);
     }
 
-    fn build_dylib(&mut self, out_filename: &Path) {
+    fn build_dylib(&mut self, crate_type: CrateType, out_filename: &Path) {
         // On mac we need to tell the linker to let this library be rpathed
         if self.sess.target.is_like_osx {
             if !self.is_ld {
@@ -428,7 +432,7 @@ impl<'a> GccLinker<'a> {
                     let mut out_implib = OsString::from("--out-implib=");
                     out_implib.push(out_filename.with_file_name(implib_name));
                     self.link_arg(out_implib);
-                } else {
+                } else if crate_type == CrateType::Dylib {
                     // When dylibs are linked by a full path this value will get into `DT_NEEDED`
                     // instead of the full path, so the library can be later found in some other
                     // location than that specific path.
@@ -475,7 +479,12 @@ impl<'a> Linker for GccLinker<'a> {
         !self.is_ld
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        crate_type: CrateType,
+        out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicNoPicExe => {
                 if !self.is_ld && self.is_gnu {
@@ -510,10 +519,10 @@ impl<'a> Linker for GccLinker<'a> {
                     self.link_args(&["-static", "-pie", "--no-dynamic-linker", "-z", "text"]);
                 }
             }
-            LinkOutputKind::DynamicDylib => self.build_dylib(out_filename),
+            LinkOutputKind::DynamicDylib => self.build_dylib(crate_type, out_filename),
             LinkOutputKind::StaticDylib => {
                 self.link_or_cc_arg("-static");
-                self.build_dylib(out_filename);
+                self.build_dylib(crate_type, out_filename);
             }
             LinkOutputKind::WasiReactorExe => {
                 self.link_args(&["--entry", "_initialize"]);
@@ -754,7 +763,7 @@ impl<'a> Linker for GccLinker<'a> {
         if self.sess.target.is_like_osx {
             // Write a plain, newline-separated list of symbols
             let res: io::Result<()> = try {
-                let mut f = BufWriter::new(File::create(&path)?);
+                let mut f = File::create_buffered(&path)?;
                 for sym in symbols {
                     debug!("  _{sym}");
                     writeln!(f, "_{sym}")?;
@@ -765,7 +774,7 @@ impl<'a> Linker for GccLinker<'a> {
             }
         } else if is_windows {
             let res: io::Result<()> = try {
-                let mut f = BufWriter::new(File::create(&path)?);
+                let mut f = File::create_buffered(&path)?;
 
                 // .def file similar to MSVC one but without LIBRARY section
                 // because LD doesn't like when it's empty
@@ -781,7 +790,7 @@ impl<'a> Linker for GccLinker<'a> {
         } else {
             // Write an LD version script
             let res: io::Result<()> = try {
-                let mut f = BufWriter::new(File::create(&path)?);
+                let mut f = File::create_buffered(&path)?;
                 writeln!(f, "{{")?;
                 if !symbols.is_empty() {
                     writeln!(f, "  global:")?;
@@ -867,7 +876,12 @@ impl<'a> Linker for MsvcLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicNoPicExe
             | LinkOutputKind::DynamicPicExe
@@ -1059,7 +1073,7 @@ impl<'a> Linker for MsvcLinker<'a> {
 
         let path = tmpdir.join("lib.def");
         let res: io::Result<()> = try {
-            let mut f = BufWriter::new(File::create(&path)?);
+            let mut f = File::create_buffered(&path)?;
 
             // Start off with the standard module name header and then go
             // straight to exports.
@@ -1125,7 +1139,13 @@ impl<'a> Linker for EmLinker<'a> {
         true
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_dylib_by_name(&mut self, name: &str, _verbatim: bool, _as_needed: bool) {
         // Emscripten always links statically
@@ -1274,7 +1294,12 @@ impl<'a> Linker for WasmLd<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, _out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicNoPicExe
             | LinkOutputKind::DynamicPicExe
@@ -1423,7 +1448,13 @@ impl<'a> Linker for L4Bender<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, name: &str, _verbatim: bool, whole_archive: bool) {
         self.hint_static();
@@ -1569,7 +1600,12 @@ impl<'a> Linker for AixLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicDylib => {
                 self.hint_dynamic();
@@ -1648,7 +1684,7 @@ impl<'a> Linker for AixLinker<'a> {
     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 = BufWriter::new(File::create(&path)?);
+            let mut f = File::create_buffered(&path)?;
             // FIXME: use llvm-nm to generate export list.
             for symbol in symbols {
                 debug!("  _{symbol}");
@@ -1776,7 +1812,13 @@ impl<'a> Linker for PtxLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) {
         panic!("staticlibs not supported")
@@ -1842,7 +1884,13 @@ impl<'a> Linker for LlbcLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) {
         panic!("staticlibs not supported")
@@ -1913,7 +1961,13 @@ impl<'a> Linker for BpfLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) {
         panic!("staticlibs not supported")
@@ -1961,7 +2015,7 @@ impl<'a> Linker for BpfLinker<'a> {
     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 = BufWriter::new(File::create(&path)?);
+            let mut f = File::create_buffered(&path)?;
             for sym in symbols {
                 writeln!(f, "{sym}")?;
             }
diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs
index 06433484ea3..8857fda1e97 100644
--- a/compiler/rustc_codegen_ssa/src/back/metadata.rs
+++ b/compiler/rustc_codegen_ssa/src/back/metadata.rs
@@ -402,13 +402,17 @@ fn macho_object_build_version_for_target(target: &Target) -> object::write::Mach
     let platform =
         rustc_target::spec::current_apple_platform(target).expect("unknown Apple target OS");
     let min_os = rustc_target::spec::current_apple_deployment_target(target);
-    let (sdk_major, sdk_minor) =
-        rustc_target::spec::current_apple_sdk_version(platform).expect("unknown Apple target OS");
 
     let mut build_version = object::write::MachOBuildVersion::default();
     build_version.platform = platform;
     build_version.minos = pack_version(min_os);
-    build_version.sdk = pack_version((sdk_major, sdk_minor, 0));
+    // The version here does not _really_ matter, since it is only used at runtime, and we specify
+    // it when linking the final binary, so we will omit the version. This is also what LLVM does,
+    // and the tooling also allows this (and shows the SDK version as `n/a`). Finally, it is the
+    // semantically correct choice, as the SDK has not influenced the binary generated by rustc at
+    // this point in time.
+    build_version.sdk = 0;
+
     build_version
 }
 
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 4d81ff933dd..e22dd8373bd 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -11,7 +11,6 @@ use rustc_ast::attr;
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_data_structures::memmap::Mmap;
 use rustc_data_structures::profiling::{SelfProfilerRef, VerboseTimingGuard};
-use rustc_data_structures::sync::Lrc;
 use rustc_errors::emitter::Emitter;
 use rustc_errors::translation::Translate;
 use rustc_errors::{
@@ -1889,7 +1888,7 @@ impl SharedEmitter {
 }
 
 impl Translate for SharedEmitter {
-    fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+    fn fluent_bundle(&self) -> Option<&FluentBundle> {
         None
     }
 
@@ -1924,7 +1923,7 @@ impl Emitter for SharedEmitter {
         );
     }
 
-    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+    fn source_map(&self) -> Option<&SourceMap> {
         None
     }
 }