rustc_target: introduce Arch

Improve type safety by using an enum rather than strings.

Author: tamird

src/abi.rs

@@ -12,6 +12,8 @@ use rustc_middle::ty::layout::LayoutOf;
 #[cfg(feature = "master")]
 use rustc_session::config;
 use rustc_target::callconv::{ArgAttributes, CastTarget, FnAbi, PassMode};
+#[cfg(feature = "master")]
+use rustc_target::spec::Arch;
 
 use crate::builder::Builder;
 use crate::context::CodegenCx;
@@ -233,12 +235,12 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
 
     #[cfg(feature = "master")]
     fn gcc_cconv(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Option<FnAttribute<'gcc>> {
-        conv_to_fn_attribute(self.conv, &cx.tcx.sess.target.arch)
+        conv_to_fn_attribute(self.conv, cx.tcx.sess.target.arch)
     }
 }
 
 #[cfg(feature = "master")]
-pub fn conv_to_fn_attribute<'gcc>(conv: CanonAbi, arch: &str) -> Option<FnAttribute<'gcc>> {
+pub fn conv_to_fn_attribute<'gcc>(conv: CanonAbi, arch: Arch) -> Option<FnAttribute<'gcc>> {
     let attribute = match conv {
         CanonAbi::C | CanonAbi::Rust => return None,
         CanonAbi::RustCold => FnAttribute::Cold,
@@ -251,15 +253,11 @@ pub fn conv_to_fn_attribute<'gcc>(conv: CanonAbi, arch: &str) -> Option<FnAttrib
             ArmCall::CCmseNonSecureEntry => FnAttribute::ArmCmseNonsecureEntry,
             ArmCall::Aapcs => FnAttribute::ArmPcs("aapcs"),
         },
-        CanonAbi::GpuKernel => {
-            if arch == "amdgpu" {
-                FnAttribute::GcnAmdGpuHsaKernel
-            } else if arch == "nvptx64" {
-                FnAttribute::NvptxKernel
-            } else {
-                panic!("Architecture {} does not support GpuKernel calling convention", arch);
-            }
-        }
+        CanonAbi::GpuKernel => match arch {
+            Arch::AmdGpu => FnAttribute::GcnAmdGpuHsaKernel,
+            Arch::Nvptx64 => FnAttribute::NvptxKernel,
+            arch => panic!("Arch {arch} does not support GpuKernel calling convention"),
+        },
         // TODO(antoyo): check if those AVR attributes are mapped correctly.
         CanonAbi::Interrupt(interrupt_kind) => match interrupt_kind {
             InterruptKind::Avr => FnAttribute::AvrSignal,

src/attributes.rs

@@ -9,6 +9,8 @@ use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 #[cfg(feature = "master")]
 use rustc_middle::mir::TerminatorKind;
 use rustc_middle::ty;
+#[cfg(feature = "master")]
+use rustc_target::spec::Arch;
 
 use crate::context::CodegenCx;
 use crate::gcc_util::to_gcc_features;
@@ -70,7 +72,7 @@ fn inline_attr<'gcc, 'tcx>(
         InlineAttr::Hint => Some(FnAttribute::Inline),
         InlineAttr::Force { .. } => Some(FnAttribute::AlwaysInline),
         InlineAttr::Never => {
-            if cx.sess().target.arch != "amdgpu" {
+            if cx.sess().target.arch != Arch::AmdGpu {
                 Some(FnAttribute::NoInline)
             } else {
                 None
@@ -153,8 +155,8 @@ pub fn from_fn_attrs<'gcc, 'tcx>(
         .join(",");
     if !target_features.is_empty() {
         #[cfg(feature = "master")]
-        match cx.sess().target.arch.as_ref() {
-            "x86" | "x86_64" | "powerpc" => {
+        match cx.sess().target.arch {
+            Arch::X86 | Arch::X86_64 | Arch::PowerPC => {
                 func.add_attribute(FnAttribute::Target(&target_features))
             }
             // The target attribute is not supported on other targets in GCC.

src/base.rs

@@ -15,9 +15,9 @@ use rustc_middle::mir::mono::Visibility;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::DebugInfo;
 use rustc_span::Symbol;
-use rustc_target::spec::RelocModel;
 #[cfg(feature = "master")]
 use rustc_target::spec::SymbolVisibility;
+use rustc_target::spec::{Arch, RelocModel};
 
 use crate::builder::Builder;
 use crate::context::CodegenCx;
@@ -116,7 +116,7 @@ pub fn compile_codegen_unit(
             .map(|string| &string[1..])
             .collect();
 
-        if !disabled_features.contains("avx") && tcx.sess.target.arch == "x86_64" {
+        if !disabled_features.contains("avx") && tcx.sess.target.arch == Arch::X86_64 {
             // NOTE: we always enable AVX because the equivalent of llvm.x86.sse2.cmp.pd in GCC for
             // SSE2 is multiple builtins, so we use the AVX __builtin_ia32_cmppd instead.
             // FIXME(antoyo): use the proper builtins for llvm.x86.sse2.cmp.pd and similar.

src/context.rs

@@ -487,7 +487,7 @@ impl<'gcc, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         let entry_name = self.sess().target.entry_name.as_ref();
         if !self.functions.borrow().contains_key(entry_name) {
             #[cfg(feature = "master")]
-            let conv = conv_to_fn_attribute(self.sess().target.entry_abi, &self.sess().target.arch);
+            let conv = conv_to_fn_attribute(self.sess().target.entry_abi, self.sess().target.arch);
             #[cfg(not(feature = "master"))]
             let conv = None;
             Some(self.declare_entry_fn(entry_name, fn_type, conv))

src/gcc_util.rs

@@ -3,6 +3,7 @@ use gccjit::Context;
 use rustc_codegen_ssa::target_features;
 use rustc_data_structures::smallvec::{SmallVec, smallvec};
 use rustc_session::Session;
+use rustc_target::spec::Arch;
 
 fn gcc_features_by_flags(sess: &Session, features: &mut Vec<String>) {
     target_features::retpoline_features_by_flags(sess, features);
@@ -65,44 +66,47 @@ pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<Stri
 
 // To find a list of GCC's names, check https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
 pub fn to_gcc_features<'a>(sess: &Session, s: &'a str) -> SmallVec<[&'a str; 2]> {
-    let arch = if sess.target.arch == "x86_64" { "x86" } else { &*sess.target.arch };
     // cSpell:disable
-    match (arch, s) {
+    match (sess.target.arch, s) {
         // FIXME: seems like x87 does not exist?
-        ("x86", "x87") => smallvec![],
-        ("x86", "sse4.2") => smallvec!["sse4.2", "crc32"],
-        ("x86", "pclmulqdq") => smallvec!["pclmul"],
-        ("x86", "rdrand") => smallvec!["rdrnd"],
-        ("x86", "bmi1") => smallvec!["bmi"],
-        ("x86", "cmpxchg16b") => smallvec!["cx16"],
-        ("x86", "avx512vaes") => smallvec!["vaes"],
-        ("x86", "avx512gfni") => smallvec!["gfni"],
-        ("x86", "avx512vpclmulqdq") => smallvec!["vpclmulqdq"],
+        (Arch::X86 | Arch::X86_64, "x87") => smallvec![],
+        (Arch::X86 | Arch::X86_64, "sse4.2") => smallvec!["sse4.2", "crc32"],
+        (Arch::X86 | Arch::X86_64, "pclmulqdq") => smallvec!["pclmul"],
+        (Arch::X86 | Arch::X86_64, "rdrand") => smallvec!["rdrnd"],
+        (Arch::X86 | Arch::X86_64, "bmi1") => smallvec!["bmi"],
+        (Arch::X86 | Arch::X86_64, "cmpxchg16b") => smallvec!["cx16"],
+        (Arch::X86 | Arch::X86_64, "avx512vaes") => smallvec!["vaes"],
+        (Arch::X86 | Arch::X86_64, "avx512gfni") => smallvec!["gfni"],
+        (Arch::X86 | Arch::X86_64, "avx512vpclmulqdq") => smallvec!["vpclmulqdq"],
         // NOTE: seems like GCC requires 'avx512bw' for 'avx512vbmi2'.
-        ("x86", "avx512vbmi2") => smallvec!["avx512vbmi2", "avx512bw"],
+        (Arch::X86 | Arch::X86_64, "avx512vbmi2") => {
+            smallvec!["avx512vbmi2", "avx512bw"]
+        }
         // NOTE: seems like GCC requires 'avx512bw' for 'avx512bitalg'.
-        ("x86", "avx512bitalg") => smallvec!["avx512bitalg", "avx512bw"],
-        ("aarch64", "rcpc2") => smallvec!["rcpc-immo"],
-        ("aarch64", "dpb") => smallvec!["ccpp"],
-        ("aarch64", "dpb2") => smallvec!["ccdp"],
-        ("aarch64", "frintts") => smallvec!["fptoint"],
-        ("aarch64", "fcma") => smallvec!["complxnum"],
-        ("aarch64", "pmuv3") => smallvec!["perfmon"],
-        ("aarch64", "paca") => smallvec!["pauth"],
-        ("aarch64", "pacg") => smallvec!["pauth"],
+        (Arch::X86 | Arch::X86_64, "avx512bitalg") => {
+            smallvec!["avx512bitalg", "avx512bw"]
+        }
+        (Arch::AArch64, "rcpc2") => smallvec!["rcpc-immo"],
+        (Arch::AArch64, "dpb") => smallvec!["ccpp"],
+        (Arch::AArch64, "dpb2") => smallvec!["ccdp"],
+        (Arch::AArch64, "frintts") => smallvec!["fptoint"],
+        (Arch::AArch64, "fcma") => smallvec!["complxnum"],
+        (Arch::AArch64, "pmuv3") => smallvec!["perfmon"],
+        (Arch::AArch64, "paca") => smallvec!["pauth"],
+        (Arch::AArch64, "pacg") => smallvec!["pauth"],
         // Rust ties fp and neon together. In GCC neon implicitly enables fp,
         // but we manually enable neon when a feature only implicitly enables fp
-        ("aarch64", "f32mm") => smallvec!["f32mm", "neon"],
-        ("aarch64", "f64mm") => smallvec!["f64mm", "neon"],
-        ("aarch64", "fhm") => smallvec!["fp16fml", "neon"],
-        ("aarch64", "fp16") => smallvec!["fullfp16", "neon"],
-        ("aarch64", "jsconv") => smallvec!["jsconv", "neon"],
-        ("aarch64", "sve") => smallvec!["sve", "neon"],
-        ("aarch64", "sve2") => smallvec!["sve2", "neon"],
-        ("aarch64", "sve2-aes") => smallvec!["sve2-aes", "neon"],
-        ("aarch64", "sve2-sm4") => smallvec!["sve2-sm4", "neon"],
-        ("aarch64", "sve2-sha3") => smallvec!["sve2-sha3", "neon"],
-        ("aarch64", "sve2-bitperm") => smallvec!["sve2-bitperm", "neon"],
+        (Arch::AArch64, "f32mm") => smallvec!["f32mm", "neon"],
+        (Arch::AArch64, "f64mm") => smallvec!["f64mm", "neon"],
+        (Arch::AArch64, "fhm") => smallvec!["fp16fml", "neon"],
+        (Arch::AArch64, "fp16") => smallvec!["fullfp16", "neon"],
+        (Arch::AArch64, "jsconv") => smallvec!["jsconv", "neon"],
+        (Arch::AArch64, "sve") => smallvec!["sve", "neon"],
+        (Arch::AArch64, "sve2") => smallvec!["sve2", "neon"],
+        (Arch::AArch64, "sve2-aes") => smallvec!["sve2-aes", "neon"],
+        (Arch::AArch64, "sve2-sm4") => smallvec!["sve2-sm4", "neon"],
+        (Arch::AArch64, "sve2-sha3") => smallvec!["sve2-sha3", "neon"],
+        (Arch::AArch64, "sve2-bitperm") => smallvec!["sve2-bitperm", "neon"],
         (_, s) => smallvec![s],
     }
     // cSpell:enable

src/lib.rs

@@ -103,7 +103,7 @@ use rustc_middle::util::Providers;
 use rustc_session::Session;
 use rustc_session::config::{OptLevel, OutputFilenames};
 use rustc_span::Symbol;
-use rustc_target::spec::RelocModel;
+use rustc_target::spec::{Arch, RelocModel};
 use tempfile::TempDir;
 
 use crate::back::lto::ModuleBuffer;
@@ -249,7 +249,7 @@ impl CodegenBackend for GccCodegenBackend {
 
 fn new_context<'gcc, 'tcx>(tcx: TyCtxt<'tcx>) -> Context<'gcc> {
     let context = Context::default();
-    if tcx.sess.target.arch == "x86" || tcx.sess.target.arch == "x86_64" {
+    if matches!(tcx.sess.target.arch, Arch::X86 | Arch::X86_64) {
         context.add_command_line_option("-masm=intel");
     }
     #[cfg(feature = "master")]