Update to bitflags 2 in the compiler

This involves lots of breaking changes. There are two big changes that
force changes. The first is that the bitflag types now don't
automatically implement normal derive traits, so we need to derive them
manually.

Additionally, bitflags now have a hidden inner type by default, which
breaks our custom derives. The bitflags docs recommend using the impl
form in these cases, which I did.

Author: Noratrieb

compiler/rustc_abi/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 rand = { version = "0.8.4", default-features = false, optional = true }
 rand_xoshiro = { version = "0.6.0", optional = true }
 rustc_data_structures = { path = "../rustc_data_structures", optional = true  }

compiler/rustc_abi/src/lib.rs

@@ -29,10 +29,12 @@ pub use layout::LayoutCalculator;
 /// instead of implementing everything in `rustc_middle`.
 pub trait HashStableContext {}
 
+#[derive(Clone, Copy, PartialEq, Eq, Default)]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+pub struct ReprFlags(u8);
+
 bitflags! {
-    #[derive(Default)]
-    #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
-    pub struct ReprFlags: u8 {
+    impl ReprFlags: u8 {
         const IS_C               = 1 << 0;
         const IS_SIMD            = 1 << 1;
         const IS_TRANSPARENT     = 1 << 2;
@@ -42,11 +44,12 @@ bitflags! {
         // the seed stored in `ReprOptions.layout_seed`
         const RANDOMIZE_LAYOUT   = 1 << 4;
         // Any of these flags being set prevent field reordering optimisation.
-        const IS_UNOPTIMISABLE   = ReprFlags::IS_C.bits
-                                 | ReprFlags::IS_SIMD.bits
-                                 | ReprFlags::IS_LINEAR.bits;
+        const IS_UNOPTIMISABLE   = ReprFlags::IS_C.bits()
+                                 | ReprFlags::IS_SIMD.bits()
+                                 | ReprFlags::IS_LINEAR.bits();
     }
 }
+rustc_data_structures::external_bitflags_debug! { ReprFlags }
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]

compiler/rustc_ast/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 memchr = "2.5.0"
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_index = { path = "../rustc_index" }

compiler/rustc_ast/src/ast.rs

@@ -2171,9 +2171,10 @@ pub enum InlineAsmRegOrRegClass {
     RegClass(Symbol),
 }
 
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Encodable, Decodable, HashStable_Generic)]
+pub struct InlineAsmOptions(u16);
 bitflags::bitflags! {
-    #[derive(Encodable, Decodable, HashStable_Generic)]
-    pub struct InlineAsmOptions: u16 {
+    impl InlineAsmOptions: u16 {
         const PURE            = 1 << 0;
         const NOMEM           = 1 << 1;
         const READONLY        = 1 << 2;
@@ -2186,6 +2187,12 @@ bitflags::bitflags! {
     }
 }
 
+impl std::fmt::Debug for InlineAsmOptions {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        bitflags::parser::to_writer(self, f)
+    }
+}
+
 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Hash, HashStable_Generic)]
 pub enum InlineAsmTemplatePiece {
     String(String),

compiler/rustc_codegen_llvm/Cargo.toml

@@ -8,7 +8,7 @@ test = false
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.0"
+bitflags = "2.4.1"
 itertools = "0.11"
 libc = "0.2"
 measureme = "10.0.0"

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -722,7 +722,7 @@ pub mod debuginfo {
     // These values **must** match with LLVMRustDIFlags!!
     bitflags! {
         #[repr(transparent)]
-        #[derive(Default)]
+        #[derive(Clone, Copy, Default)]
         pub struct DIFlags: u32 {
             const FlagZero                = 0;
             const FlagPrivate             = 1;
@@ -751,7 +751,7 @@ pub mod debuginfo {
     // These values **must** match with LLVMRustDISPFlags!!
     bitflags! {
         #[repr(transparent)]
-        #[derive(Default)]
+        #[derive(Clone, Copy, Default)]
         pub struct DISPFlags: u32 {
             const SPFlagZero              = 0;
             const SPFlagVirtual           = 1;

compiler/rustc_codegen_ssa/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 ar_archive_writer = "0.1.5"
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 cc = "1.0.69"
 itertools = "0.11"
 jobserver = "0.1.27"

compiler/rustc_codegen_ssa/src/lib.rs

@@ -110,6 +110,7 @@ pub enum ModuleKind {
 }
 
 bitflags::bitflags! {
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
     pub struct MemFlags: u8 {
         const VOLATILE = 1 << 0;
         const NONTEMPORAL = 1 << 1;

compiler/rustc_data_structures/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 arrayvec = { version = "0.7", default-features = false }
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 elsa = "=1.7.1"
 ena = "0.14.2"
 indexmap = { version = "2.0.0" }

compiler/rustc_data_structures/src/lib.rs

@@ -150,3 +150,14 @@ pub fn make_display(f: impl Fn(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl
 // See comments in src/librustc_middle/lib.rs
 #[doc(hidden)]
 pub fn __noop_fix_for_27438() {}
+
+#[macro_export]
+macro_rules! external_bitflags_debug {
+    ($Name:ident) => {
+        impl ::std::fmt::Debug for $Name {
+            fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
+                ::bitflags::parser::to_writer(self, f)
+            }
+        }
+    };
+}

compiler/rustc_data_structures/src/profiling.rs

@@ -101,6 +101,7 @@ use parking_lot::RwLock;
 use smallvec::SmallVec;
 
 bitflags::bitflags! {
+    #[derive(Clone, Copy)]
     struct EventFilter: u16 {
         const GENERIC_ACTIVITIES  = 1 << 0;
         const QUERY_PROVIDERS     = 1 << 1;
@@ -114,14 +115,14 @@ bitflags::bitflags! {
         const INCR_RESULT_HASHING = 1 << 8;
         const ARTIFACT_SIZES = 1 << 9;
 
-        const DEFAULT = Self::GENERIC_ACTIVITIES.bits |
-                        Self::QUERY_PROVIDERS.bits |
-                        Self::QUERY_BLOCKED.bits |
-                        Self::INCR_CACHE_LOADS.bits |
-                        Self::INCR_RESULT_HASHING.bits |
-                        Self::ARTIFACT_SIZES.bits;
+        const DEFAULT = Self::GENERIC_ACTIVITIES.bits() |
+                        Self::QUERY_PROVIDERS.bits() |
+                        Self::QUERY_BLOCKED.bits() |
+                        Self::INCR_CACHE_LOADS.bits() |
+                        Self::INCR_RESULT_HASHING.bits() |
+                        Self::ARTIFACT_SIZES.bits();
 
-        const ARGS = Self::QUERY_KEYS.bits | Self::FUNCTION_ARGS.bits;
+        const ARGS = Self::QUERY_KEYS.bits() | Self::FUNCTION_ARGS.bits();
     }
 }
 

compiler/rustc_metadata/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 libloading = "0.7.1"
 odht = { version = "0.3.1", features = ["nightly"] }
 rustc_ast = { path = "../rustc_ast" }

compiler/rustc_middle/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 derive_more = "0.99.17"
 either = "1.5.0"
 field-offset = "0.3.5"

compiler/rustc_middle/src/middle/codegen_fn_attrs.rs

@@ -45,9 +45,10 @@ pub struct CodegenFnAttrs {
     pub alignment: Option<u32>,
 }
 
+#[derive(Clone, Copy, PartialEq, Eq, TyEncodable, TyDecodable, HashStable)]
+pub struct CodegenFnAttrFlags(u32);
 bitflags! {
-    #[derive(TyEncodable, TyDecodable, HashStable)]
-    pub struct CodegenFnAttrFlags: u32 {
+    impl CodegenFnAttrFlags: u32 {
         /// `#[cold]`: a hint to LLVM that this function, when called, is never on
         /// the hot path.
         const COLD                      = 1 << 0;
@@ -104,6 +105,7 @@ bitflags! {
         const NO_BUILTINS               = 1 << 20;
     }
 }
+rustc_data_structures::external_bitflags_debug! { CodegenFnAttrFlags }
 
 impl CodegenFnAttrs {
     pub const EMPTY: &'static Self = &Self::new();

compiler/rustc_middle/src/ty/adt.rs

@@ -24,9 +24,10 @@ use std::str;
 
 use super::{Destructor, FieldDef, GenericPredicates, Ty, TyCtxt, VariantDef, VariantDiscr};
 
+#[derive(Clone, Copy, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)]
+pub struct AdtFlags(u16);
 bitflags! {
-    #[derive(HashStable, TyEncodable, TyDecodable)]
-    pub struct AdtFlags: u16 {
+    impl AdtFlags: u16 {
         const NO_ADT_FLAGS        = 0;
         /// Indicates whether the ADT is an enum.
         const IS_ENUM             = 1 << 0;
@@ -51,6 +52,7 @@ bitflags! {
         const IS_UNSAFE_CELL              = 1 << 9;
     }
 }
+rustc_data_structures::external_bitflags_debug! { AdtFlags }
 
 /// The definition of a user-defined type, e.g., a `struct`, `enum`, or `union`.
 ///

compiler/rustc_middle/src/ty/mod.rs

@@ -1771,9 +1771,10 @@ pub struct Destructor {
     pub constness: hir::Constness,
 }
 
+#[derive(Clone, Copy, PartialEq, Eq, HashStable, TyEncodable, TyDecodable)]
+pub struct VariantFlags(u8);
 bitflags! {
-    #[derive(HashStable, TyEncodable, TyDecodable)]
-    pub struct VariantFlags: u8 {
+    impl VariantFlags: u8 {
         const NO_VARIANT_FLAGS        = 0;
         /// Indicates whether the field list of this variant is `#[non_exhaustive]`.
         const IS_FIELD_LIST_NON_EXHAUSTIVE = 1 << 0;
@@ -1782,6 +1783,7 @@ bitflags! {
         const IS_RECOVERED = 1 << 1;
     }
 }
+rustc_data_structures::external_bitflags_debug! { VariantFlags }
 
 /// Definition of a variant -- a struct's fields or an enum variant.
 #[derive(Debug, HashStable, TyEncodable, TyDecodable)]

compiler/rustc_parse/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.0"
+bitflags = "2.4.1"
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_parse/src/parser/mod.rs

@@ -46,6 +46,7 @@ use crate::errors::{
 };
 
 bitflags::bitflags! {
+    #[derive(Clone, Copy)]
     struct Restrictions: u8 {
         const STMT_EXPR         = 1 << 0;
         const NO_STRUCT_LITERAL = 1 << 1;

compiler/rustc_resolve/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 pulldown-cmark = { version = "0.9.3", default-features = false }
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }

compiler/rustc_resolve/src/ident.rs

@@ -377,6 +377,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         ignore_binding: Option<NameBinding<'a>>,
     ) -> Result<NameBinding<'a>, Determinacy> {
         bitflags::bitflags! {
+            #[derive(Clone, Copy)]
             struct Flags: u8 {
                 const MACRO_RULES          = 1 << 0;
                 const MODULE               = 1 << 1;

compiler/rustc_session/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 getopts = "0.2"
 rustc_ast = { path = "../rustc_ast" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_session/src/config.rs

@@ -1021,6 +1021,7 @@ impl OutputFilenames {
 
 bitflags::bitflags! {
     /// Scopes used to determined if it need to apply to --remap-path-prefix
+    #[derive(Clone, Copy, PartialEq, Eq, Hash)]
     pub struct RemapPathScopeComponents: u8 {
         /// Apply remappings to the expansion of std::file!() macro
         const MACRO = 1 << 0;
@@ -1041,7 +1042,7 @@ bitflags::bitflags! {
         /// An alias for macro,unsplit-debuginfo,split-debuginfo-path. This
         /// ensures all paths in compiled executables or libraries are remapped
         /// but not elsewhere.
-        const OBJECT = Self::MACRO.bits | Self::UNSPLIT_DEBUGINFO.bits | Self::SPLIT_DEBUGINFO_PATH.bits;
+        const OBJECT = Self::MACRO.bits() | Self::UNSPLIT_DEBUGINFO.bits() | Self::SPLIT_DEBUGINFO_PATH.bits();
     }
 }
 

compiler/rustc_symbol_mangling/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 punycode = "0.4.0"
 rustc-demangle = "0.1.21"
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_symbol_mangling/src/typeid.rs

@@ -11,6 +11,7 @@ use twox_hash::XxHash64;
 
 bitflags! {
     /// Options for typeid_for_fnabi and typeid_for_fnsig.
+    #[derive(Clone, Copy, Debug)]
     pub struct TypeIdOptions: u32 {
         const GENERALIZE_POINTERS = 1;
         const GENERALIZE_REPR_C = 2;

compiler/rustc_target/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-bitflags = "1.2.1"
+bitflags = "2.4.1"
 rustc_abi = { path = "../rustc_abi" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_feature = { path = "../rustc_feature" }

compiler/rustc_target/src/abi/call/mod.rs

@@ -93,9 +93,10 @@ pub use attr_impl::ArgAttribute;
 #[allow(unused)]
 mod attr_impl {
     // The subset of llvm::Attribute needed for arguments, packed into a bitfield.
+    #[derive(Clone, Copy, Default, Hash, PartialEq, Eq, HashStable_Generic)]
+    pub struct ArgAttribute(u8);
     bitflags::bitflags! {
-        #[derive(Default, HashStable_Generic)]
-        pub struct ArgAttribute: u8 {
+        impl ArgAttribute: u8 {
             const NoAlias   = 1 << 1;
             const NoCapture = 1 << 2;
             const NonNull   = 1 << 3;
@@ -104,6 +105,7 @@ mod attr_impl {
             const NoUndef = 1 << 6;
         }
     }
+    rustc_data_structures::external_bitflags_debug! { ArgAttribute }
 }
 
 /// Sometimes an ABI requires small integers to be extended to a full or partial register. This enum