remove #[derive(TryFromU32)]

seems like it could just be replaced with a declarative macro

Author: fee1-dead

compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs

@@ -6,7 +6,6 @@ use rustc_abi::Align;
 use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, ConstCodegenMethods};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_index::IndexVec;
-use rustc_macros::TryFromU32;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::RemapFileNameExt;
 use rustc_session::config::RemapPathScopeComponents;
@@ -27,12 +26,14 @@ mod unused;
 /// or at least the subset that we know and care about.
 ///
 /// Note that version `n` is encoded as `(n-1)`.
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, TryFromU32)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
 enum CovmapVersion {
     /// Used by LLVM 18 onwards.
     Version7 = 6,
 }
 
+crate::impl_try_from_u32!(CovmapVersion { Version7 });
+
 impl CovmapVersion {
     fn to_u32(self) -> u32 {
         self as u32

compiler/rustc_codegen_llvm/src/lib.rs

@@ -79,6 +79,27 @@ mod value;
 
 rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
 
+// FIXME(fee1-dead) use `macro_attr` feature once that is available in bootstrap beta
+macro_rules! impl_try_from_u32 {
+    ($Type:ident { $($Variant:ident),*$(,)? }) => {
+        impl ::core::convert::TryFrom<u32> for $Type {
+            type Error = u32;
+            #[allow(deprecated)] // Don't warn about deprecated variants.
+            fn try_from(value: u32) -> ::core::result::Result<$Type, Self::Error> {
+                fn _assert_all_variants_provided(x: $Type) {
+                    match x {
+                        $($Type::$Variant => (),)*
+                    }
+                }
+                $( if value == const { $Type::$Variant as u32 } { return Ok($Type::$Variant) } )*
+                Err(value)
+            }
+        }
+    }
+}
+
+pub(crate) use impl_try_from_u32;
+
 #[derive(Clone)]
 pub struct LlvmCodegenBackend(());
 

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -20,7 +20,6 @@ use std::ptr;
 
 use bitflags::bitflags;
 use libc::{c_char, c_int, c_uchar, c_uint, c_ulonglong, c_void, size_t};
-use rustc_macros::TryFromU32;
 use rustc_target::spec::SymbolVisibility;
 
 use super::RustString;
@@ -110,7 +109,7 @@ pub(crate) enum TailCallKind {
 /// LLVM CallingConv::ID. Should we wrap this?
 ///
 /// See <https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/IR/CallingConv.h>
-#[derive(Copy, Clone, PartialEq, Debug, TryFromU32)]
+#[derive(Copy, Clone, PartialEq, Debug)]
 #[repr(C)]
 pub(crate) enum CallConv {
     CCallConv = 0,
@@ -134,8 +133,32 @@ pub(crate) enum CallConv {
     AmdgpuKernel = 91,
 }
 
+crate::impl_try_from_u32! {
+    CallConv {
+        CCallConv,
+        FastCallConv,
+        ColdCallConv,
+        PreserveMost,
+        PreserveAll,
+        Tail,
+        X86StdcallCallConv,
+        X86FastcallCallConv,
+        ArmAapcsCallConv,
+        Msp430Intr,
+        X86_ThisCall,
+        PtxKernel,
+        X86_64_SysV,
+        X86_64_Win64,
+        X86_VectorCall,
+        X86_Intr,
+        AvrNonBlockingInterrupt,
+        AvrInterrupt,
+        AmdgpuKernel,
+    }
+}
+
 /// Must match the layout of `LLVMLinkage`.
-#[derive(Copy, Clone, PartialEq, TryFromU32)]
+#[derive(Copy, Clone, PartialEq)]
 #[repr(C)]
 pub(crate) enum Linkage {
     ExternalLinkage = 0,
@@ -161,15 +184,41 @@ pub(crate) enum Linkage {
     LinkerPrivateWeakLinkage = 16,
 }
 
+crate::impl_try_from_u32! {
+    Linkage {
+        ExternalLinkage,
+        AvailableExternallyLinkage,
+        LinkOnceAnyLinkage,
+        LinkOnceODRLinkage,
+        LinkOnceODRAutoHideLinkage,
+        WeakAnyLinkage,
+        WeakODRLinkage,
+        AppendingLinkage,
+        InternalLinkage,
+        PrivateLinkage,
+        DLLImportLinkage,
+        DLLExportLinkage,
+        ExternalWeakLinkage,
+        GhostLinkage,
+        CommonLinkage,
+        LinkerPrivateLinkage,
+        LinkerPrivateWeakLinkage,
+    }
+}
+
 /// Must match the layout of `LLVMVisibility`.
 #[repr(C)]
-#[derive(Copy, Clone, PartialEq, TryFromU32)]
+#[derive(Copy, Clone, PartialEq)]
 pub(crate) enum Visibility {
     Default = 0,
     Hidden = 1,
     Protected = 2,
 }
 
+crate::impl_try_from_u32! {
+    Visibility { Default, Hidden, Protected }
+}
+
 impl Visibility {
     pub(crate) fn from_generic(visibility: SymbolVisibility) -> Self {
         match visibility {

compiler/rustc_macros/src/lib.rs

@@ -18,7 +18,6 @@ mod print_attribute;
 mod query;
 mod serialize;
 mod symbols;
-mod try_from;
 mod type_foldable;
 mod type_visitable;
 mod visitable;
@@ -176,14 +175,6 @@ decl_derive!(
         applicability)] => diagnostics::subdiagnostic_derive
 );
 
-decl_derive! {
-    [TryFromU32] =>
-    /// Derives `TryFrom<u32>` for the annotated `enum`, which must have no fields.
-    /// Each variant maps to the value it would produce under an `as u32` cast.
-    ///
-    /// The error type is `u32`.
-    try_from::try_from_u32
-}
 decl_derive! {
     [PrintAttribute] =>
     /// Derives `PrintAttribute` for `AttributeKind`.