rustc_target: introduce Env

Improve type safety by using an enum rather than strings.

Author: tamird

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -47,7 +47,7 @@ use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_session::Session;
 use rustc_session::config::OutputFilenames;
 use rustc_span::{Symbol, sym};
-use rustc_target::spec::{ABI, Arch};
+use rustc_target::spec::{ABI, Arch, Env};
 
 pub use crate::config::*;
 use crate::prelude::*;
@@ -215,7 +215,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
             // available when using a LLVM-built sysroot.
             Arch::X86_64
                 if sess.target.os == "windows"
-                    && sess.target.env == "gnu"
+                    && sess.target.env == Env::Gnu
                     && sess.target.abi != ABI::Llvm =>
             {
                 false

compiler/rustc_codegen_llvm/src/callee.rs

@@ -7,7 +7,7 @@
 use rustc_codegen_ssa::common;
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, HasTypingEnv};
 use rustc_middle::ty::{self, Instance, TypeVisitableExt};
-use rustc_target::spec::Arch;
+use rustc_target::spec::{Arch, Env};
 use tracing::debug;
 
 use crate::context::CodegenCx;
@@ -145,7 +145,7 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
         if cx.use_dll_storage_attrs
             && let Some(library) = tcx.native_library(instance_def_id)
             && library.kind.is_dllimport()
-            && !matches!(tcx.sess.target.env.as_ref(), "gnu" | "uclibc")
+            && !matches!(tcx.sess.target.env, Env::Gnu | Env::Uclibc)
         {
             llvm::set_dllimport_storage_class(llfn);
         }

compiler/rustc_codegen_llvm/src/context.rs

@@ -29,7 +29,7 @@ use rustc_span::source_map::Spanned;
 use rustc_span::{DUMMY_SP, Span, Symbol};
 use rustc_symbol_mangling::mangle_internal_symbol;
 use rustc_target::spec::{
-    ABI, Arch, HasTargetSpec, RelocModel, SmallDataThresholdSupport, Target, TlsModel,
+    ABI, Arch, Env, HasTargetSpec, RelocModel, SmallDataThresholdSupport, Target, TlsModel,
 };
 use smallvec::SmallVec;
 
@@ -336,7 +336,7 @@ pub(crate) unsafe fn create_module<'ll>(
     // Control Flow Guard is currently only supported by MSVC and LLVM on Windows.
     if sess.target.is_like_msvc
         || (sess.target.options.os == "windows"
-            && sess.target.options.env == "gnu"
+            && sess.target.options.env == Env::Gnu
             && sess.target.options.abi == ABI::Llvm)
     {
         match sess.opts.cg.control_flow_guard {
@@ -710,7 +710,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
             },
         );
 
-        if self.tcx.sess.target.env == "sim" {
+        if self.tcx.sess.target.env == Env::Sim {
             llvm::add_module_flag_u32(
                 self.llmod,
                 llvm::ModuleFlagMergeBehavior::Error,

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -15,7 +15,9 @@ use rustc_fs_util::path_to_c_string;
 use rustc_middle::bug;
 use rustc_session::Session;
 use rustc_session::config::{PrintKind, PrintRequest};
-use rustc_target::spec::{ABI, Arch, MergeFunctions, PanicStrategy, SmallDataThresholdSupport};
+use rustc_target::spec::{
+    ABI, Arch, Env, MergeFunctions, PanicStrategy, SmallDataThresholdSupport,
+};
 use smallvec::{SmallVec, smallvec};
 
 use crate::back::write::create_informational_target_machine;
@@ -352,7 +354,7 @@ pub(crate) fn target_config(sess: &Session) -> TargetConfig {
 fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
     let target_arch = &sess.target.arch;
     let target_os = sess.target.options.os.as_ref();
-    let target_env = sess.target.options.env.as_ref();
+    let target_env = &sess.target.options.env;
     let target_abi = &sess.target.options.abi;
     let target_pointer_width = sess.target.pointer_width;
     let version = get_version();
@@ -371,7 +373,7 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         // Selection failure <https://github.com/llvm/llvm-project/issues/50374> (fixed in llvm21)
         (Arch::S390x, _) if lt_21_0_0 => false,
         // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054>
-        (Arch::X86_64, "windows") if target_env == "gnu" && *target_abi != ABI::Llvm => false,
+        (Arch::X86_64, "windows") if *target_env == Env::Gnu && *target_abi != ABI::Llvm => false,
         // Infinite recursion <https://github.com/llvm/llvm-project/issues/97981>
         (Arch::CSky, _) => false,
         (Arch::Hexagon, _) if lt_21_0_0 => false, // (fixed in llvm21)
@@ -403,7 +405,7 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         // not fail if our compiler-builtins is linked. (fixed in llvm21)
         (Arch::X86, _) if lt_21_0_0 => false,
         // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054>
-        (Arch::X86_64, "windows") if target_env == "gnu" && *target_abi != ABI::Llvm => false,
+        (Arch::X86_64, "windows") if *target_env == Env::Gnu && *target_abi != ABI::Llvm => false,
         // There are no known problems on other platforms, so the only requirement is that symbols
         // are available. `compiler-builtins` provides all symbols required for core `f128`
         // support, so this should work for everything else.
@@ -424,7 +426,7 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) {
         // (ld is 80-bit extended precision).
         //
         // musl does not implement the symbols required for f128 math at all.
-        _ if target_env == "musl" => false,
+        _ if *target_env == Env::Musl => false,
         (Arch::X86_64, _) => false,
         (_, "linux") if target_pointer_width == 64 => true,
         _ => false,

compiler/rustc_codegen_ssa/src/back/apple.rs

@@ -6,7 +6,7 @@ use itertools::Itertools;
 use rustc_middle::middle::exported_symbols::SymbolExportKind;
 use rustc_session::Session;
 pub(super) use rustc_target::spec::apple::OSVersion;
-use rustc_target::spec::{Arch, Target};
+use rustc_target::spec::{Arch, Env, Target};
 use tracing::debug;
 
 use crate::errors::{XcrunError, XcrunSdkPathWarning};
@@ -17,35 +17,35 @@ mod tests;
 
 /// The canonical name of the desired SDK for a given target.
 pub(super) fn sdk_name(target: &Target) -> &'static str {
-    match (&*target.os, &*target.env) {
-        ("macos", "") => "MacOSX",
-        ("ios", "") => "iPhoneOS",
-        ("ios", "sim") => "iPhoneSimulator",
+    match (&*target.os, &target.env) {
+        ("macos", Env::Unspecified) => "MacOSX",
+        ("ios", Env::Unspecified) => "iPhoneOS",
+        ("ios", Env::Sim) => "iPhoneSimulator",
         // Mac Catalyst uses the macOS SDK
-        ("ios", "macabi") => "MacOSX",
-        ("tvos", "") => "AppleTVOS",
-        ("tvos", "sim") => "AppleTVSimulator",
-        ("visionos", "") => "XROS",
-        ("visionos", "sim") => "XRSimulator",
-        ("watchos", "") => "WatchOS",
-        ("watchos", "sim") => "WatchSimulator",
+        ("ios", Env::MacAbi) => "MacOSX",
+        ("tvos", Env::Unspecified) => "AppleTVOS",
+        ("tvos", Env::Sim) => "AppleTVSimulator",
+        ("visionos", Env::Unspecified) => "XROS",
+        ("visionos", Env::Sim) => "XRSimulator",
+        ("watchos", Env::Unspecified) => "WatchOS",
+        ("watchos", Env::Sim) => "WatchSimulator",
         (os, abi) => unreachable!("invalid os '{os}' / abi '{abi}' combination for Apple target"),
     }
 }
 
 pub(super) fn macho_platform(target: &Target) -> u32 {
-    match (&*target.os, &*target.env) {
+    match (&*target.os, &target.env) {
         ("macos", _) => object::macho::PLATFORM_MACOS,
-        ("ios", "macabi") => object::macho::PLATFORM_MACCATALYST,
-        ("ios", "sim") => object::macho::PLATFORM_IOSSIMULATOR,
+        ("ios", Env::MacAbi) => object::macho::PLATFORM_MACCATALYST,
+        ("ios", Env::Sim) => object::macho::PLATFORM_IOSSIMULATOR,
         ("ios", _) => object::macho::PLATFORM_IOS,
-        ("watchos", "sim") => object::macho::PLATFORM_WATCHOSSIMULATOR,
+        ("watchos", Env::Sim) => object::macho::PLATFORM_WATCHOSSIMULATOR,
         ("watchos", _) => object::macho::PLATFORM_WATCHOS,
-        ("tvos", "sim") => object::macho::PLATFORM_TVOSSIMULATOR,
+        ("tvos", Env::Sim) => object::macho::PLATFORM_TVOSSIMULATOR,
         ("tvos", _) => object::macho::PLATFORM_TVOS,
-        ("visionos", "sim") => object::macho::PLATFORM_XROSSIMULATOR,
+        ("visionos", Env::Sim) => object::macho::PLATFORM_XROSSIMULATOR,
         ("visionos", _) => object::macho::PLATFORM_XROS,
-        _ => unreachable!("tried to get Mach-O platform for non-Apple target"),
+        (os, env) => unreachable!("invalid os '{os}' / env '{env}' combination for Apple target"),
     }
 }
 

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -46,7 +46,7 @@ use rustc_session::{Session, filesearch};
 use rustc_span::Symbol;
 use rustc_target::spec::crt_objects::CrtObjects;
 use rustc_target::spec::{
-    BinaryFormat, Cc, LinkOutputKind, LinkSelfContainedComponents, LinkSelfContainedDefault,
+    BinaryFormat, Cc, Env, LinkOutputKind, LinkSelfContainedComponents, LinkSelfContainedDefault,
     LinkerFeatures, LinkerFlavor, LinkerFlavorCli, Lld, RelocModel, RelroLevel, SanitizerSet,
     SplitDebuginfo, Vendor,
 };
@@ -3072,7 +3072,7 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
     // `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_env = &*sess.target.env;
+    let target_env = &sess.target.env;
 
     // The architecture name to forward to the linker.
     //
@@ -3124,12 +3124,12 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
         // > - xros-simulator
         // > - driverkit
         let platform_name = match (target_os, target_env) {
-            (os, "") => os,
-            ("ios", "macabi") => "mac-catalyst",
-            ("ios", "sim") => "ios-simulator",
-            ("tvos", "sim") => "tvos-simulator",
-            ("watchos", "sim") => "watchos-simulator",
-            ("visionos", "sim") => "visionos-simulator",
+            (os, Env::Unspecified) => os,
+            ("ios", Env::MacAbi) => "mac-catalyst",
+            ("ios", Env::Sim) => "ios-simulator",
+            ("tvos", Env::Sim) => "tvos-simulator",
+            ("watchos", Env::Sim) => "watchos-simulator",
+            ("visionos", Env::Sim) => "visionos-simulator",
             _ => bug!("invalid OS/env combination for Apple target: {target_os}, {target_env}"),
         };
 

compiler/rustc_codegen_ssa/src/common.rs

@@ -7,7 +7,7 @@ use rustc_middle::ty::{self, Instance, TyCtxt};
 use rustc_middle::{bug, mir, span_bug};
 use rustc_session::cstore::{DllCallingConvention, DllImport};
 use rustc_span::Span;
-use rustc_target::spec::{ABI, Target, Vendor};
+use rustc_target::spec::{ABI, Env, Target, Vendor};
 
 use crate::traits::*;
 
@@ -173,7 +173,7 @@ pub fn asm_const_to_str<'tcx>(
 pub fn is_mingw_gnu_toolchain(target: &Target) -> bool {
     target.vendor == Vendor::Pc
         && target.os == "windows"
-        && target.env == "gnu"
+        && target.env == Env::Gnu
         && target.abi == ABI::Unspecified
 }
 

compiler/rustc_metadata/src/native_libs.rs

@@ -15,7 +15,7 @@ use rustc_session::cstore::{DllCallingConvention, DllImport, ForeignModule, Nati
 use rustc_session::search_paths::PathKind;
 use rustc_span::Symbol;
 use rustc_span::def_id::{DefId, LOCAL_CRATE};
-use rustc_target::spec::{Arch, BinaryFormat, LinkSelfContainedComponents, Vendor};
+use rustc_target::spec::{Arch, BinaryFormat, Env, LinkSelfContainedComponents, Vendor};
 
 use crate::errors;
 
@@ -79,7 +79,7 @@ pub fn walk_native_lib_search_dirs<R>(
     // Mac Catalyst uses the macOS SDK, but to link to iOS-specific frameworks
     // we must have the support library stubs in the library search path (#121430).
     if let Some(sdk_root) = apple_sdk_root
-        && sess.target.env == "macabi"
+        && sess.target.env == Env::MacAbi
     {
         f(&sdk_root.join("System/iOSSupport/usr/lib"), false)?;
         f(&sdk_root.join("System/iOSSupport/System/Library/Frameworks"), true)?;

compiler/rustc_session/src/config/cfg.rs

@@ -242,7 +242,7 @@ pub(crate) fn default_configuration(sess: &Session) -> Cfg {
     ins_sym!(sym::target_abi, sess.target.abi.desc_symbol());
     ins_sym!(sym::target_arch, sess.target.arch.desc_symbol());
     ins_str!(sym::target_endian, sess.target.endian.as_str());
-    ins_str!(sym::target_env, &sess.target.env);
+    ins_sym!(sym::target_env, sess.target.env.desc_symbol());
 
     for family in sess.target.families.as_ref() {
         ins_str!(sym::target_family, family);
@@ -450,7 +450,7 @@ impl CheckCfg {
                     values_target_abi.insert(target.options.abi.desc_symbol());
                     values_target_arch.insert(target.arch.desc_symbol());
                     values_target_endian.insert(Symbol::intern(target.options.endian.as_str()));
-                    values_target_env.insert(Symbol::intern(&target.options.env));
+                    values_target_env.insert(target.options.env.desc_symbol());
                     values_target_family.extend(
                         target.options.families.iter().map(|family| Symbol::intern(family)),
                     );

compiler/rustc_target/src/asm/aarch64.rs

@@ -4,7 +4,7 @@ use rustc_data_structures::fx::FxIndexSet;
 use rustc_span::{Symbol, sym};
 
 use super::{InlineAsmArch, InlineAsmType, ModifierInfo};
-use crate::spec::{RelocModel, Target};
+use crate::spec::{Env, RelocModel, Target};
 
 def_reg_class! {
     AArch64 AArch64InlineAsmRegClass {
@@ -77,7 +77,7 @@ pub(crate) fn target_reserves_x18(target: &Target, target_features: &FxIndexSet<
     // Note that +reserve-x18 is currently not set for the above targets.
     target.os == "android"
         || target.os == "fuchsia"
-        || target.env == "ohos"
+        || target.env == Env::Ohos
         || target.is_like_darwin
         || target.is_like_windows
         || target_features.contains(&sym::reserve_x18)