Use LLVMGetTypeKind

Author: Zalathar

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -333,10 +333,15 @@ impl RealPredicate {
     }
 }
 
-/// LLVMTypeKind
-#[derive(Copy, Clone, PartialEq, Debug)]
+/// Must match the layout of `LLVMTypeKind`.
+///
+/// Use [`RawEnum<TypeKind>`] for values of `LLVMTypeKind` returned from LLVM,
+/// to avoid risk of UB if LLVM adds new enum values.
+///
+/// All of LLVM's variants should be declared here, even if no Rust-side code refers
+/// to them, because unknown variants will cause [`RawEnum::to_rust`] to panic.
+#[derive(Copy, Clone, PartialEq, Debug, TryFromU32)]
 #[repr(C)]
-#[expect(dead_code, reason = "Some variants are unused, but are kept to match LLVM-C")]
 pub(crate) enum TypeKind {
     Void = 0,
     Half = 1,
@@ -1047,6 +1052,8 @@ unsafe extern "C" {
         CanThrow: llvm::Bool,
     ) -> &'ll Value;
 
+    pub(crate) safe fn LLVMGetTypeKind(Ty: &Type) -> RawEnum<TypeKind>;
+
     // Operations on integer types
     pub(crate) fn LLVMInt1TypeInContext(C: &Context) -> &Type;
     pub(crate) fn LLVMInt8TypeInContext(C: &Context) -> &Type;
@@ -1842,9 +1849,6 @@ unsafe extern "C" {
     // Create and destroy contexts.
     pub(crate) fn LLVMRustContextCreate(shouldDiscardNames: bool) -> &'static mut Context;
 
-    /// See llvm::LLVMTypeKind::getTypeID.
-    pub(crate) fn LLVMRustGetTypeKind(Ty: &Type) -> TypeKind;
-
     // Operations on all values
     pub(crate) fn LLVMRustGlobalAddMetadata<'a>(
         Val: &'a Value,

compiler/rustc_codegen_llvm/src/type_.rs

@@ -204,7 +204,7 @@ impl<'ll, CX: Borrow<SCx<'ll>>> BaseTypeCodegenMethods for GenericCx<'ll, CX> {
     }
 
     fn type_kind(&self, ty: &'ll Type) -> TypeKind {
-        unsafe { llvm::LLVMRustGetTypeKind(ty).to_generic() }
+        llvm::LLVMGetTypeKind(ty).to_rust().to_generic()
     }
 
     fn type_ptr(&self) -> &'ll Type {

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1460,60 +1460,6 @@ LLVMRustGetDiagInfoKind(LLVMDiagnosticInfoRef DI) {
   return toRust((DiagnosticKind)unwrap(DI)->getKind());
 }
 
-// This is kept distinct from LLVMGetTypeKind, because when
-// a new type kind is added, the Rust-side enum must be
-// updated or UB will result.
-extern "C" LLVMTypeKind LLVMRustGetTypeKind(LLVMTypeRef Ty) {
-  switch (unwrap(Ty)->getTypeID()) {
-  case Type::VoidTyID:
-    return LLVMVoidTypeKind;
-  case Type::HalfTyID:
-    return LLVMHalfTypeKind;
-  case Type::FloatTyID:
-    return LLVMFloatTypeKind;
-  case Type::DoubleTyID:
-    return LLVMDoubleTypeKind;
-  case Type::X86_FP80TyID:
-    return LLVMX86_FP80TypeKind;
-  case Type::FP128TyID:
-    return LLVMFP128TypeKind;
-  case Type::PPC_FP128TyID:
-    return LLVMPPC_FP128TypeKind;
-  case Type::LabelTyID:
-    return LLVMLabelTypeKind;
-  case Type::MetadataTyID:
-    return LLVMMetadataTypeKind;
-  case Type::IntegerTyID:
-    return LLVMIntegerTypeKind;
-  case Type::FunctionTyID:
-    return LLVMFunctionTypeKind;
-  case Type::StructTyID:
-    return LLVMStructTypeKind;
-  case Type::ArrayTyID:
-    return LLVMArrayTypeKind;
-  case Type::PointerTyID:
-    return LLVMPointerTypeKind;
-  case Type::FixedVectorTyID:
-    return LLVMVectorTypeKind;
-  case Type::TokenTyID:
-    return LLVMTokenTypeKind;
-  case Type::ScalableVectorTyID:
-    return LLVMScalableVectorTypeKind;
-  case Type::BFloatTyID:
-    return LLVMBFloatTypeKind;
-  case Type::X86_AMXTyID:
-    return LLVMX86_AMXTypeKind;
-  default: {
-    std::string error;
-    auto stream = llvm::raw_string_ostream(error);
-    stream << "Rust does not support the TypeID: " << unwrap(Ty)->getTypeID()
-           << " for the type: " << *unwrap(Ty);
-    stream.flush();
-    report_fatal_error(error.c_str());
-  }
-  }
-}
-
 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(SMDiagnostic, LLVMSMDiagnosticRef)
 
 extern "C" LLVMSMDiagnosticRef LLVMRustGetSMDiagnostic(LLVMDiagnosticInfoRef DI,