rustc_target: introduce Abi

Improve type safety by using an enum rather than strings.

Author: tamird

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -49,7 +49,7 @@ 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::Arch;
+use rustc_target::spec::{Abi, Arch};
 
 pub use crate::config::*;
 use crate::prelude::*;
@@ -186,7 +186,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
         let has_reliable_f16_f128 = !(sess.target.arch == Arch::X86_64
             && sess.target.os == "windows"
             && sess.target.env == "gnu"
-            && sess.target.abi != "llvm");
+            && sess.target.abi != Abi::Llvm);
 
         TargetConfig {
             target_features,

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::{
-    Arch, HasTargetSpec, RelocModel, SmallDataThresholdSupport, Target, TlsModel,
+    Abi, Arch, HasTargetSpec, RelocModel, SmallDataThresholdSupport, Target, TlsModel,
 };
 use smallvec::SmallVec;
 
@@ -337,7 +337,7 @@ pub(crate) unsafe fn create_module<'ll>(
     if sess.target.is_like_msvc
         || (sess.target.options.os == "windows"
             && sess.target.options.env == "gnu"
-            && sess.target.options.abi == "llvm")
+            && sess.target.options.abi == Abi::Llvm)
     {
         match sess.opts.cg.control_flow_guard {
             CFGuard::Disabled => {}

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -15,7 +15,7 @@ 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::{Arch, MergeFunctions, PanicStrategy, SmallDataThresholdSupport};
+use rustc_target::spec::{Abi, Arch, MergeFunctions, PanicStrategy, SmallDataThresholdSupport};
 use smallvec::{SmallVec, smallvec};
 
 use crate::back::write::create_informational_target_machine;
@@ -353,7 +353,7 @@ 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_abi = sess.target.options.abi.as_ref();
+    let target_abi = &sess.target.options.abi;
     let target_pointer_width = sess.target.pointer_width;
     let version = get_version();
     let lt_20_1_1 = version < (20, 1, 1);
@@ -371,7 +371,7 @@ 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 != "llvm" => false,
+        (Arch::X86_64, "windows") if target_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 +403,7 @@ 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 != "llvm" => false,
+        (Arch::X86_64, "windows") if target_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.

compiler/rustc_codegen_llvm/src/va_arg.rs

@@ -7,7 +7,7 @@ use rustc_codegen_ssa::traits::{
 };
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
-use rustc_target::spec::Arch;
+use rustc_target::spec::{Abi, Arch};
 
 use crate::builder::Builder;
 use crate::llvm::{Type, Value};
@@ -270,7 +270,7 @@ fn emit_powerpc_va_arg<'ll, 'tcx>(
 
     // Rust does not currently support any powerpc softfloat targets.
     let target = &bx.cx.tcx.sess.target;
-    let is_soft_float_abi = target.abi == "softfloat";
+    let is_soft_float_abi = target.abi == Abi::SoftFloat;
     assert!(!is_soft_float_abi);
 
     // All instances of VaArgSafe are passed directly.

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,
+    Abi, BinaryFormat, Cc, LinkOutputKind, LinkSelfContainedComponents, LinkSelfContainedDefault,
     LinkerFeatures, LinkerFlavor, LinkerFlavorCli, Lld, RelocModel, RelroLevel, SanitizerSet,
     SplitDebuginfo,
 };
@@ -1819,7 +1819,7 @@ fn self_contained_components(
                 LinkSelfContainedDefault::InferredForMusl => sess.crt_static(Some(crate_type)),
                 LinkSelfContainedDefault::InferredForMingw => {
                     sess.host == sess.target
-                        && sess.target.abi != "uwp"
+                        && sess.target.abi != Abi::Uwp
                         && detect_self_contained_mingw(sess, linker)
                 }
             }

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -17,7 +17,7 @@ use rustc_middle::middle::exported_symbols::{
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_session::config::{self, CrateType, DebugInfo, LinkerPluginLto, Lto, OptLevel, Strip};
-use rustc_target::spec::{Arch, Cc, LinkOutputKind, LinkerFlavor, Lld};
+use rustc_target::spec::{Abi, Arch, Cc, LinkOutputKind, LinkerFlavor, Lld};
 use tracing::{debug, warn};
 
 use super::command::Command;
@@ -83,7 +83,7 @@ pub(crate) fn get_linker<'a>(
     // To comply with the Windows App Certification Kit,
     // MSVC needs to link with the Store versions of the runtime libraries (vcruntime, msvcrt, etc).
     let t = &sess.target;
-    if matches!(flavor, LinkerFlavor::Msvc(..)) && t.abi == "uwp" {
+    if matches!(flavor, LinkerFlavor::Msvc(..)) && t.abi == Abi::Uwp {
         if let Some(ref tool) = msvc_tool {
             let original_path = tool.path();
             if let Some(root_lib_path) = original_path.ancestors().nth(4) {
@@ -134,7 +134,7 @@ pub(crate) fn get_linker<'a>(
 
     // FIXME: Move `/LIBPATH` addition for uwp targets from the linker construction
     // to the linker args construction.
-    assert!(cmd.get_args().is_empty() || sess.target.abi == "uwp");
+    assert!(cmd.get_args().is_empty() || sess.target.abi == Abi::Uwp);
     match flavor {
         LinkerFlavor::Unix(Cc::No) if sess.target.os == "l4re" => {
             Box::new(L4Bender::new(cmd, sess)) as Box<dyn Linker>

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -20,7 +20,7 @@ use rustc_metadata::fs::METADATA_FILENAME;
 use rustc_middle::bug;
 use rustc_session::Session;
 use rustc_span::sym;
-use rustc_target::spec::{RelocModel, Target, ef_avr_arch};
+use rustc_target::spec::{Abi, RelocModel, Target, ef_avr_arch};
 use tracing::debug;
 
 use super::apple;
@@ -379,11 +379,11 @@ pub(super) fn elf_e_flags(architecture: Architecture, sess: &Session) -> u32 {
             }
         }
         Architecture::Csky => {
-            let e_flags = match sess.target.options.abi.as_ref() {
-                "abiv2" => elf::EF_CSKY_ABIV2,
-                _ => elf::EF_CSKY_ABIV1,
-            };
-            e_flags
+            if matches!(sess.target.options.abi, Abi::AbiV2) {
+                elf::EF_CSKY_ABIV2
+            } else {
+                elf::EF_CSKY_ABIV1
+            }
         }
         Architecture::PowerPc64 => {
             const EF_PPC64_ABI_UNKNOWN: u32 = 0;

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::Target;
+use rustc_target::spec::{Abi, Target};
 
 use crate::traits::*;
 
@@ -171,7 +171,7 @@ pub fn asm_const_to_str<'tcx>(
 }
 
 pub fn is_mingw_gnu_toolchain(target: &Target) -> bool {
-    target.os == "windows" && target.env == "gnu" && target.abi.is_empty()
+    target.os == "windows" && target.env == "gnu" && target.abi == Abi::Unspecified
 }
 
 pub fn i686_decorated_name(

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};
+use rustc_target::spec::{Abi, Arch, BinaryFormat, LinkSelfContainedComponents};
 
 use crate::errors;
 
@@ -67,7 +67,7 @@ pub fn walk_native_lib_search_dirs<R>(
     // FIXME: On AIX this also has the side-effect of making the list of library search paths
     // non-empty, which is needed or the linker may decide to record the LIBPATH env, if
     // defined, as the search path instead of appending the default search paths.
-    if sess.target.abi == "fortanix"
+    if sess.target.abi == Abi::Fortanix
         || sess.target.os == "linux"
         || sess.target.os == "fuchsia"
         || sess.target.is_like_aix

compiler/rustc_session/src/config/cfg.rs

@@ -239,7 +239,7 @@ pub(crate) fn default_configuration(sess: &Session) -> Cfg {
         ins_none!(sym::sanitizer_cfi_normalize_integers);
     }
 
-    ins_str!(sym::target_abi, &sess.target.abi);
+    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);
@@ -447,7 +447,7 @@ impl CheckCfg {
                 };
 
                 for target in Target::builtins().chain(iter::once(current_target.clone())) {
-                    values_target_abi.insert(Symbol::intern(&target.options.abi));
+                    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));