Merge from rustc

Author: The rustc-dev-guide Cronjob Bot

Cargo.lock

@@ -4673,6 +4673,7 @@ dependencies = [
  "bincode",
  "rustc-hash 2.1.1",
  "serde",
+ "serde_derive",
  "serde_json",
 ]
 

Cargo.toml

@@ -4,7 +4,6 @@ members = [
 # tidy-alphabetical-start
   "compiler/rustc",
   "src/build_helper",
-  "src/etc/test-float-parse",
   "src/rustc-std-workspace/rustc-std-workspace-alloc",
   "src/rustc-std-workspace/rustc-std-workspace-core",
   "src/rustc-std-workspace/rustc-std-workspace-std",
@@ -41,6 +40,7 @@ members = [
   "src/tools/rustdoc-themes",
   "src/tools/rustfmt",
   "src/tools/suggest-tests",
+  "src/tools/test-float-parse",
   "src/tools/tidy",
   "src/tools/tier-check",
   "src/tools/unicode-table-generator",

compiler/rustc_abi/src/canon_abi.rs

@@ -0,0 +1,129 @@
+use std::fmt;
+
+#[cfg(feature = "nightly")]
+use rustc_macros::HashStable_Generic;
+
+use crate::ExternAbi;
+
+/// Calling convention to determine codegen
+///
+/// CanonAbi erases certain distinctions ExternAbi preserves, but remains target-dependent.
+/// There are still both target-specific variants and aliasing variants, though much fewer.
+/// The reason for this step is the frontend may wish to show an ExternAbi but implement that ABI
+/// using a different ABI than the string per se, or describe irrelevant differences, e.g.
+/// - extern "system"
+/// - extern "cdecl"
+/// - extern "C-unwind"
+/// In that sense, this erases mere syntactic distinctions to create a canonical *directive*,
+/// rather than picking the "actual" ABI.
+#[derive(Copy, Clone, Debug)]
+#[derive(PartialOrd, Ord, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
+pub enum CanonAbi {
+    // NOTE: the use of nested variants for some ABIs is for many targets they don't matter,
+    // and this pushes the complexity of their reasoning to target-specific code,
+    // allowing a `match` to easily exhaustively ignore these subcategories of variants.
+    // Otherwise it is very tempting to avoid matching exhaustively!
+    C,
+    Rust,
+    RustCold,
+
+    /// ABIs relevant to 32-bit Arm targets
+    Arm(ArmCall),
+    /// ABI relevant to GPUs: the entry point for a GPU kernel
+    GpuKernel,
+
+    /// ABIs relevant to bare-metal interrupt targets
+    // FIXME(workingjubilee): a particular reason for this nesting is we might not need these?
+    // interrupt ABIs should have the same properties:
+    // - uncallable by Rust calls, as LLVM rejects it in most cases
+    // - uses a preserve-all-registers *callee* convention
+    // - should always return `-> !` (effectively... it can't use normal `ret`)
+    // what differs between targets is
+    // - allowed arguments: x86 differs slightly, having 2-3 arguments which are handled magically
+    // - may need special prologues/epilogues for some interrupts, without affecting "call ABI"
+    Interrupt(InterruptKind),
+
+    /// ABIs relevant to Windows or x86 targets
+    X86(X86Call),
+}
+
+impl fmt::Display for CanonAbi {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // convert to the ExternAbi that *shares a string* with this CanonAbi.
+        // FIXME: ideally we'd avoid printing `CanonAbi`, and preserve `ExternAbi` everywhere
+        // that we need to generate error messages.
+        let erased_abi = match self {
+            CanonAbi::C => ExternAbi::C { unwind: false },
+            CanonAbi::Rust => ExternAbi::Rust,
+            CanonAbi::RustCold => ExternAbi::RustCold,
+            CanonAbi::Arm(arm_call) => match arm_call {
+                ArmCall::Aapcs => ExternAbi::Aapcs { unwind: false },
+                ArmCall::CCmseNonSecureCall => ExternAbi::CCmseNonSecureCall,
+                ArmCall::CCmseNonSecureEntry => ExternAbi::CCmseNonSecureEntry,
+            },
+            CanonAbi::GpuKernel => ExternAbi::GpuKernel,
+            CanonAbi::Interrupt(interrupt_kind) => match interrupt_kind {
+                InterruptKind::Avr => ExternAbi::AvrInterrupt,
+                InterruptKind::AvrNonBlocking => ExternAbi::AvrNonBlockingInterrupt,
+                InterruptKind::Msp430 => ExternAbi::Msp430Interrupt,
+                InterruptKind::RiscvMachine => ExternAbi::RiscvInterruptM,
+                InterruptKind::RiscvSupervisor => ExternAbi::RiscvInterruptS,
+                InterruptKind::X86 => ExternAbi::X86Interrupt,
+            },
+            CanonAbi::X86(x86_call) => match x86_call {
+                X86Call::Fastcall => ExternAbi::Fastcall { unwind: false },
+                X86Call::Stdcall => ExternAbi::Stdcall { unwind: false },
+                X86Call::SysV64 => ExternAbi::SysV64 { unwind: false },
+                X86Call::Thiscall => ExternAbi::Thiscall { unwind: false },
+                X86Call::Vectorcall => ExternAbi::Vectorcall { unwind: false },
+                X86Call::Win64 => ExternAbi::Win64 { unwind: false },
+            },
+        };
+        erased_abi.as_str().fmt(f)
+    }
+}
+
+/// Callee codegen for interrupts
+///
+/// This is named differently from the "Call" enums because it is different:
+/// these "ABI" differences are not relevant to callers, since there is "no caller".
+/// These only affect callee codegen. making their categorization as distinct ABIs a bit peculiar.
+#[derive(Copy, Clone, Debug)]
+#[derive(PartialOrd, Ord, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
+pub enum InterruptKind {
+    Avr,
+    AvrNonBlocking,
+    Msp430,
+    RiscvMachine,
+    RiscvSupervisor,
+    X86,
+}
+
+/// ABIs defined for x86-{32,64}
+///
+/// One of SysV64 or Win64 may alias the C ABI, and arguably Win64 is cross-platform now?
+#[derive(Clone, Copy, Debug)]
+#[derive(PartialOrd, Ord, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
+pub enum X86Call {
+    /// "fastcall" has both GNU and Windows variants
+    Fastcall,
+    /// "stdcall" has both GNU and Windows variants
+    Stdcall,
+    SysV64,
+    Thiscall,
+    Vectorcall,
+    Win64,
+}
+
+/// ABIs defined for 32-bit Arm
+#[derive(Copy, Clone, Debug)]
+#[derive(PartialOrd, Ord, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
+pub enum ArmCall {
+    Aapcs,
+    CCmseNonSecureCall,
+    CCmseNonSecureEntry,
+}

compiler/rustc_abi/src/extern_abi.rs

@@ -7,69 +7,98 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableOrd};
 #[cfg(feature = "nightly")]
 use rustc_macros::{Decodable, Encodable};
 
+use crate::AbiFromStrErr;
+
 #[cfg(test)]
 mod tests;
 
-use ExternAbi as Abi;
-
+/// ABI we expect to see within `extern "{abi}"`
 #[derive(Clone, Copy, Debug)]
 #[cfg_attr(feature = "nightly", derive(Encodable, Decodable))]
 pub enum ExternAbi {
-    // Some of the ABIs come first because every time we add a new ABI, we have to re-bless all the
-    // hashing tests. These are used in many places, so giving them stable values reduces test
-    // churn. The specific values are meaningless.
-    Rust,
+    /* universal */
+    /// presumed C ABI for the platform
     C {
         unwind: bool,
     },
-    Cdecl {
+    /// ABI of the "system" interface, e.g. the Win32 API, always "aliasing"
+    System {
         unwind: bool,
     },
-    Stdcall {
+
+    /// that's us!
+    Rust,
+    /// the mostly-unused `unboxed_closures` ABI, effectively now an impl detail unless someone
+    /// puts in the work to make it viable again... but would we need a special ABI?
+    RustCall,
+    /// For things unlikely to be called, where reducing register pressure in
+    /// `extern "Rust"` callers is worth paying extra cost in the callee.
+    /// Stronger than just `#[cold]` because `fn` pointers might be incompatible.
+    RustCold,
+
+    /// Unstable impl detail that directly uses Rust types to describe the ABI to LLVM.
+    /// Even normally-compatible Rust types can become ABI-incompatible with this ABI!
+    Unadjusted,
+
+    /// UEFI ABI, usually an alias of C, but sometimes an arch-specific alias
+    /// and only valid on platforms that have a UEFI standard
+    EfiApi,
+
+    /* arm */
+    /// Arm Architecture Procedure Call Standard, sometimes `ExternAbi::C` is an alias for this
+    Aapcs {
         unwind: bool,
     },
-    Fastcall {
+    /// extremely constrained barely-C ABI for TrustZone
+    CCmseNonSecureCall,
+    /// extremely constrained barely-C ABI for TrustZone
+    CCmseNonSecureEntry,
+
+    /* gpu */
+    /// An entry-point function called by the GPU's host
+    // FIXME: should not be callable from Rust on GPU targets, is for host's use only
+    GpuKernel,
+    /// An entry-point function called by the GPU's host
+    // FIXME: why do we have two of these?
+    PtxKernel,
+
+    /* interrupt */
+    AvrInterrupt,
+    AvrNonBlockingInterrupt,
+    Msp430Interrupt,
+    RiscvInterruptM,
+    RiscvInterruptS,
+    X86Interrupt,
+
+    /* x86 */
+    /// `ExternAbi::C` but spelled funny because x86
+    Cdecl {
         unwind: bool,
     },
-    Vectorcall {
+    /// gnu-stdcall on "unix" and win-stdcall on "windows"
+    Stdcall {
         unwind: bool,
     },
-    Thiscall {
+    /// gnu-fastcall on "unix" and win-fastcall on "windows"
+    Fastcall {
         unwind: bool,
     },
-    Aapcs {
+    /// windows C++ ABI
+    Thiscall {
         unwind: bool,
     },
-    Win64 {
+    /// uses AVX and stuff
+    Vectorcall {
         unwind: bool,
     },
+
+    /* x86_64 */
     SysV64 {
         unwind: bool,
     },
-    PtxKernel,
-    Msp430Interrupt,
-    X86Interrupt,
-    /// An entry-point function called by the GPU's host
-    // FIXME: should not be callable from Rust on GPU targets, is for host's use only
-    GpuKernel,
-    EfiApi,
-    AvrInterrupt,
-    AvrNonBlockingInterrupt,
-    CCmseNonSecureCall,
-    CCmseNonSecureEntry,
-    System {
+    Win64 {
         unwind: bool,
     },
-    RustCall,
-    /// *Not* a stable ABI, just directly use the Rust types to describe the ABI for LLVM. Even
-    /// normally ABI-compatible Rust types can become ABI-incompatible with this ABI!
-    Unadjusted,
-    /// For things unlikely to be called, where reducing register pressure in
-    /// `extern "Rust"` callers is worth paying extra cost in the callee.
-    /// Stronger than just `#[cold]` because `fn` pointers might be incompatible.
-    RustCold,
-    RiscvInterruptM,
-    RiscvInterruptS,
 }
 
 macro_rules! abi_impls {
@@ -99,11 +128,6 @@ macro_rules! abi_impls {
     }
 }
 
-#[derive(Debug)]
-pub enum AbiFromStrErr {
-    Unknown,
-}
-
 abi_impls! {
     ExternAbi = {
             C { unwind: false } =><= "C",
@@ -227,7 +251,7 @@ pub fn all_names() -> Vec<&'static str> {
 
 impl ExternAbi {
     /// Default ABI chosen for `extern fn` declarations without an explicit ABI.
-    pub const FALLBACK: Abi = Abi::C { unwind: false };
+    pub const FALLBACK: ExternAbi = ExternAbi::C { unwind: false };
 
     pub fn name(self) -> &'static str {
         self.as_str()

compiler/rustc_abi/src/layout.rs

@@ -758,7 +758,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
                         niche_variants,
                         niche_start,
                     },
-                    tag_field: 0,
+                    tag_field: FieldIdx::new(0),
                     variants: IndexVec::new(),
                 },
                 fields: FieldsShape::Arbitrary {
@@ -1072,7 +1072,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
             variants: Variants::Multiple {
                 tag,
                 tag_encoding: TagEncoding::Direct,
-                tag_field: 0,
+                tag_field: FieldIdx::new(0),
                 variants: IndexVec::new(),
             },
             fields: FieldsShape::Arbitrary {

compiler/rustc_abi/src/layout/coroutine.rs

@@ -158,7 +158,7 @@ pub(super) fn layout<
     // Build a prefix layout, including "promoting" all ineligible
     // locals as part of the prefix. We compute the layout of all of
     // these fields at once to get optimal packing.
-    let tag_index = prefix_layouts.len();
+    let tag_index = prefix_layouts.next_index();
 
     // `variant_fields` already accounts for the reserved variants, so no need to add them.
     let max_discr = (variant_fields.len() - 1) as u128;
@@ -187,7 +187,7 @@ pub(super) fn layout<
 
             // "a" (`0..b_start`) and "b" (`b_start..`) correspond to
             // "outer" and "promoted" fields respectively.
-            let b_start = FieldIdx::new(tag_index + 1);
+            let b_start = tag_index.plus(1);
             let offsets_b = IndexVec::from_raw(offsets.raw.split_off(b_start.index()));
             let offsets_a = offsets;
 

compiler/rustc_abi/src/layout/ty.rs

@@ -39,6 +39,13 @@ rustc_index::newtype_index! {
     pub struct FieldIdx {}
 }
 
+impl FieldIdx {
+    /// The second field, at index 1.
+    ///
+    /// For use alongside [`FieldIdx::ZERO`], particularly with scalar pairs.
+    pub const ONE: FieldIdx = FieldIdx::from_u32(1);
+}
+
 rustc_index::newtype_index! {
     /// The *source-order* index of a variant in a type.
     ///
@@ -274,7 +281,7 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
 
     /// Finds the one field that is not a 1-ZST.
     /// Returns `None` if there are multiple non-1-ZST fields or only 1-ZST-fields.
-    pub fn non_1zst_field<C>(&self, cx: &C) -> Option<(usize, Self)>
+    pub fn non_1zst_field<C>(&self, cx: &C) -> Option<(FieldIdx, Self)>
     where
         Ty: TyAbiInterface<'a, C> + Copy,
     {
@@ -288,7 +295,7 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
                 // More than one non-1-ZST field.
                 return None;
             }
-            found = Some((field_idx, field));
+            found = Some((FieldIdx::from_usize(field_idx), field));
         }
         found
     }