Merge branch 'move-llvm-target-versioning' into sdkroot

Author: madsmtm

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -39,6 +39,7 @@ use std::sync::Arc;
 use cranelift_codegen::isa::TargetIsa;
 use cranelift_codegen::settings::{self, Configurable};
 use rustc_codegen_ssa::CodegenResults;
+use rustc_codegen_ssa::apple::versioned_llvm_target;
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_errors::ErrorGuaranteed;
@@ -259,7 +260,9 @@ impl CodegenBackend for CraneliftCodegenBackend {
 }
 
 fn target_triple(sess: &Session) -> target_lexicon::Triple {
-    match sess.target.llvm_target.parse() {
+    // FIXME(madsmtm): Use `sess.target.llvm_target` once target-lexicon supports unversioned macOS.
+    // See <https://github.com/bytecodealliance/target-lexicon/pull/113>
+    match versioned_llvm_target(sess).parse() {
         Ok(triple) => triple,
         Err(err) => sess.dcx().fatal(format!("target not recognized: {}", err)),
     }

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -8,6 +8,7 @@ use libc::{c_char, c_int, c_void, size_t};
 use llvm::{
     LLVMRustLLVMHasZlibCompressionForDebugSymbols, LLVMRustLLVMHasZstdCompressionForDebugSymbols,
 };
+use rustc_codegen_ssa::apple::versioned_llvm_target;
 use rustc_codegen_ssa::back::link::ensure_removed;
 use rustc_codegen_ssa::back::write::{
     BitcodeSection, CodegenContext, EmitObj, ModuleConfig, TargetMachineFactoryConfig,
@@ -210,7 +211,7 @@ pub(crate) fn target_machine_factory(
         singlethread = false;
     }
 
-    let triple = SmallCStr::new(&sess.target.llvm_target);
+    let triple = SmallCStr::new(&versioned_llvm_target(sess));
     let cpu = SmallCStr::new(llvm_util::target_cpu(sess));
     let features = CString::new(target_features.join(",")).unwrap();
     let abi = SmallCStr::new(&sess.target.llvm_abiname);

compiler/rustc_codegen_llvm/src/context.rs

@@ -3,6 +3,7 @@ use std::cell::{Cell, RefCell};
 use std::ffi::{CStr, c_uint};
 use std::str;
 
+use rustc_codegen_ssa::apple::versioned_llvm_target;
 use rustc_codegen_ssa::base::{wants_msvc_seh, wants_wasm_eh};
 use rustc_codegen_ssa::errors as ssa_errors;
 use rustc_codegen_ssa::traits::*;
@@ -165,7 +166,7 @@ pub(crate) unsafe fn create_module<'ll>(
         llvm::LLVMSetDataLayout(llmod, data_layout.as_ptr());
     }
 
-    let llvm_target = SmallCStr::new(&sess.target.llvm_target);
+    let llvm_target = SmallCStr::new(&versioned_llvm_target(sess));
     unsafe {
         llvm::LLVMRustSetNormalizedTarget(llmod, llvm_target.as_ptr());
     }

compiler/rustc_codegen_ssa/messages.ftl

@@ -2,6 +2,12 @@ codegen_ssa_L4Bender_exporting_symbols_unimplemented = exporting symbols not imp
 
 codegen_ssa_add_native_library = failed to add native library {$library_path}: {$error}
 
+codegen_ssa_apple_deployment_target_invalid =
+    failed to parse deployment target specified in {$env_var}: {$error}
+
+codegen_ssa_apple_deployment_target_too_low =
+    deployment target in {$env_var} was set to {$version}, but the minimum supported by `rustc` is {$os_min}
+
 codegen_ssa_apple_sdk_error_failed_reading =
     failed reading `{$path}` while looking for SDK root: {$error}
 

compiler/rustc_codegen_ssa/src/apple.rs

@@ -1,12 +1,104 @@
+use std::borrow::Cow;
+use std::env;
 use std::fs;
 use std::io::ErrorKind;
+use std::fmt::{Display, from_fn};
 use std::path::{Path, PathBuf};
 
-use crate::errors::AppleSdkError;
+use rustc_session::Session;
+use rustc_target::spec::{
+    AppleOSVersion, apple_deployment_target_env_var, apple_minimum_deployment_target,
+    apple_os_minimum_deployment_target, apple_parse_version,
+};
+
+use crate::errors::{AppleDeploymentTarget, AppleSdkError};
 
 #[cfg(test)]
 mod tests;
 
+pub fn pretty_version(version: AppleOSVersion) -> impl Display {
+    let (major, minor, patch) = version;
+    from_fn(move |f| {
+        write!(f, "{major}.{minor}")?;
+        if patch != 0 {
+            write!(f, ".{patch}")?;
+        }
+        Ok(())
+    })
+}
+
+/// Get the deployment target based on the standard environment variables, or fall back to the
+/// minimum version supported by `rustc`.
+pub fn deployment_target(sess: &Session) -> AppleOSVersion {
+    let os_min = apple_os_minimum_deployment_target(&sess.target.os);
+    let min = apple_minimum_deployment_target(&sess.target);
+    let env_var = apple_deployment_target_env_var(&sess.target.os);
+
+    if let Ok(deployment_target) = env::var(env_var) {
+        match apple_parse_version(&deployment_target) {
+            Ok(version) => {
+                // It is common that the deployment target is set a bit too low, for example on
+                // macOS Aarch64 to also target older x86_64. So we only want to warn when variable
+                // is lower than the minimum OS supported by rustc, not when the variable is lower
+                // than the minimum for a specific target.
+                if version < os_min {
+                    sess.dcx().emit_warn(AppleDeploymentTarget::TooLow {
+                        env_var,
+                        version: pretty_version(version).to_string(),
+                        os_min: pretty_version(os_min).to_string(),
+                    });
+                }
+
+                // Raise the deployment target to the minimum supported.
+                version.max(min)
+            }
+            Err(error) => {
+                sess.dcx().emit_err(AppleDeploymentTarget::Invalid { env_var, error });
+                min
+            }
+        }
+    } else {
+        // If no deployment target variable is set, default to the minimum found above.
+        min
+    }
+}
+
+fn add_version_to_llvm_target(llvm_target: &str, deployment_target: AppleOSVersion) -> String {
+    let mut components = llvm_target.split("-");
+    let arch = components.next().expect("darwin target should have arch");
+    let vendor = components.next().expect("darwin target should have vendor");
+    let os = components.next().expect("darwin target should have os");
+    let environment = components.next();
+    assert_eq!(components.next(), None, "too many LLVM triple components");
+
+    let (major, minor, patch) = deployment_target;
+
+    assert!(
+        !os.contains(|c: char| c.is_ascii_digit()),
+        "LLVM target must not already be versioned"
+    );
+
+    if let Some(env) = environment {
+        // Insert version into OS, before environment
+        format!("{arch}-{vendor}-{os}{major}.{minor}.{patch}-{env}")
+    } else {
+        format!("{arch}-{vendor}-{os}{major}.{minor}.{patch}")
+    }
+}
+
+/// The target triple depends on the deployment target, and is required to
+/// enable features such as cross-language LTO, and for picking the right
+/// Mach-O commands.
+///
+/// Certain optimizations also depend on the deployment target.
+pub fn versioned_llvm_target(sess: &Session) -> Cow<'static, str> {
+    if sess.target.is_like_osx {
+        add_version_to_llvm_target(&sess.target.llvm_target, deployment_target(sess)).into()
+    } else {
+        sess.target.llvm_target.clone()
+    }
+}
+
 // TOCTOU is not _really_ an issue with our use of `try_exists` in here, we mostly use it for
 // diagnostics, and these directories are global state that the user may change anytime anyhow.
 fn try_exists(path: &Path) -> Result<bool, AppleSdkError> {

compiler/rustc_codegen_ssa/src/apple/tests.rs

@@ -2,7 +2,19 @@ use std::io;
 use std::path::PathBuf;
 use std::process::Command;
 
-use super::find_sdk_root;
+use super::{add_version_to_llvm_target, find_sdk_root};
+
+#[test]
+fn test_add_version_to_llvm_target() {
+    assert_eq!(
+        add_version_to_llvm_target("aarch64-apple-macosx", (10, 14, 1)),
+        "aarch64-apple-macosx10.14.1"
+    );
+    assert_eq!(
+        add_version_to_llvm_target("aarch64-apple-ios-simulator", (16, 1, 0)),
+        "aarch64-apple-ios16.1.0-simulator"
+    );
+}
 
 fn find_sdk_root_xcrun(sdk_name: &str) -> io::Result<PathBuf> {
     let output = Command::new("xcrun")

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, current_apple_deployment_target,
+    SplitDebuginfo,
 };
 use tempfile::Builder as TempFileBuilder;
 use tracing::{debug, info, warn};
@@ -50,7 +50,7 @@ use super::command::Command;
 use super::linker::{self, Linker};
 use super::metadata::{MetadataPosition, create_wrapper_file};
 use super::rpath::{self, RPathConfig};
-use crate::apple::find_sdk_root;
+use crate::apple::{deployment_target, find_sdk_root, versioned_llvm_target};
 use crate::{
     CodegenResults, CompiledModule, CrateInfo, NativeLib, common, errors,
     looks_like_rust_object_file,
@@ -2446,7 +2446,7 @@ fn add_order_independent_options(
     if flavor == LinkerFlavor::Llbc {
         cmd.link_args(&[
             "--target",
-            sess.target.llvm_target.as_ref(),
+            &versioned_llvm_target(sess),
             "--target-cpu",
             &codegen_results.crate_info.target_cpu,
         ]);
@@ -3038,7 +3038,7 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
             _ => bug!("invalid OS/ABI combination for Apple target: {target_os}, {target_abi}"),
         };
 
-        let (major, minor, patch) = current_apple_deployment_target(&sess.target);
+        let (major, minor, patch) = deployment_target(sess);
         let min_version = format!("{major}.{minor}.{patch}");
 
         // The SDK version is used at runtime when compiling with a newer SDK / version of Xcode:
@@ -3108,7 +3108,7 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
 
             // 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);
+            let (major, minor, patch) = deployment_target(sess);
             // 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}"));
@@ -3118,7 +3118,7 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
             //
             // We avoid `-m32`/`-m64`, as this is already encoded by `-arch`.
         } else {
-            cmd.cc_args(&["-target", &sess.target.llvm_target]);
+            cmd.cc_args(&["-target", &versioned_llvm_target(sess)]);
         }
     }
 }
@@ -3305,7 +3305,7 @@ fn add_lld_args(
         // targeting a different linker flavor on macOS, and that's also always
         // the case when targeting WASM.
         if sess.target.linker_flavor != sess.host.linker_flavor {
-            cmd.cc_arg(format!("--target={}", sess.target.llvm_target));
+            cmd.cc_arg(format!("--target={}", versioned_llvm_target(sess)));
         }
     }
 }

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -238,7 +238,7 @@ pub(crate) fn create_object_file(sess: &Session) -> Option<write::Object<'static
             file.set_macho_cpu_subtype(object::macho::CPU_SUBTYPE_ARM64E);
         }
 
-        file.set_macho_build_version(macho_object_build_version_for_target(&sess.target))
+        file.set_macho_build_version(macho_object_build_version_for_target(sess))
     }
     if binary_format == BinaryFormat::Coff {
         // Disable the default mangler to avoid mangling the special "@feat.00" symbol name.
@@ -391,7 +391,7 @@ pub(crate) fn create_object_file(sess: &Session) -> Option<write::Object<'static
 ///
 /// Since Xcode 15, Apple's LD apparently requires object files to use this load command, so this
 /// returns the `MachOBuildVersion` for the target to do so.
-fn macho_object_build_version_for_target(target: &Target) -> object::write::MachOBuildVersion {
+fn macho_object_build_version_for_target(sess: &Session) -> object::write::MachOBuildVersion {
     /// The `object` crate demands "X.Y.Z encoded in nibbles as xxxx.yy.zz"
     /// e.g. minOS 14.0 = 0x000E0000, or SDK 16.2 = 0x00100200
     fn pack_version((major, minor, patch): (u16, u8, u8)) -> u32 {
@@ -400,8 +400,8 @@ 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);
+        rustc_target::spec::current_apple_platform(&sess.target).expect("unknown Apple target OS");
+    let min_os = crate::apple::deployment_target(sess);
 
     let mut build_version = object::write::MachOBuildVersion::default();
     build_version.platform = platform;

compiler/rustc_codegen_ssa/src/errors.rs

@@ -2,6 +2,7 @@
 
 use std::borrow::Cow;
 use std::io::Error;
+use std::num::ParseIntError;
 use std::path::{Path, PathBuf};
 use std::process::ExitStatus;
 
@@ -532,6 +533,14 @@ pub enum ExtractBundledLibsError<'a> {
     ExtractSection { rlib: &'a Path, error: Box<dyn std::error::Error> },
 }
 
+#[derive(Diagnostic)]
+pub(crate) enum AppleDeploymentTarget {
+    #[diag(codegen_ssa_apple_deployment_target_invalid)]
+    Invalid { env_var: &'static str, error: ParseIntError },
+    #[diag(codegen_ssa_apple_deployment_target_too_low)]
+    TooLow { env_var: &'static str, version: String, os_min: String },
+}
+
 #[derive(Diagnostic, Debug)]
 pub(crate) enum AppleSdkError {
     #[diag(codegen_ssa_apple_sdk_error_failed_reading)]

compiler/rustc_codegen_ssa/src/lib.rs

@@ -6,6 +6,7 @@
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
+#![feature(debug_closure_helpers)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]