Rollup merge of #131202 - Urgau:wide-ptrs-compiler, r=jieyouxu

Use wide pointers consistenly across the compiler

This PR replace every use of "fat pointer" for the more recent "wide pointer" terminology.

Since some time T-lang as preferred the "wide pointer" terminology, as can be seen on [the last RFCs](https://github.com/search?q=repo%3Arust-lang%2Frfcs+%22wide+pointer%22&type=code), on some [lints](https://doc.rust-lang.org/rustc/lints/listing/warn-by-default.html#ambiguous-wide-pointer-comparisons), but also in [the reference](https://doc.rust-lang.org/stable/reference/expressions/operator-expr.html?highlight=wide%20pointer#pointer-to-pointer-cast).

Currently we have a [mix of both](https://github.com/search?q=repo%3Arust-lang%2Frust+%22wide+pointer%22&type=code) (including in error messages), which isn't great, but with this PR no more.

r? `@jieyouxu` (feel free to re-roll)

Author: GuillaumeGomez

compiler/rustc_codegen_cranelift/example/std_example.rs

@@ -168,7 +168,7 @@ fn main() {
 
     foo(I64X2([0, 0]));
 
-    transmute_fat_pointer();
+    transmute_wide_pointer();
 
     rust_call_abi();
 
@@ -192,7 +192,7 @@ type TwoPtrs = i64;
 #[cfg(target_pointer_width = "64")]
 type TwoPtrs = i128;
 
-fn transmute_fat_pointer() -> TwoPtrs {
+fn transmute_wide_pointer() -> TwoPtrs {
     unsafe { transmute::<_, TwoPtrs>("true !") }
 }
 

compiler/rustc_codegen_cranelift/src/base.rs

@@ -713,17 +713,17 @@ fn codegen_stmt<'tcx>(
                     let from_ty = operand.layout().ty;
                     let to_ty = fx.monomorphize(to_ty);
 
-                    fn is_fat_ptr<'tcx>(fx: &FunctionCx<'_, '_, 'tcx>, ty: Ty<'tcx>) -> bool {
+                    fn is_wide_ptr<'tcx>(fx: &FunctionCx<'_, '_, 'tcx>, ty: Ty<'tcx>) -> bool {
                         ty.builtin_deref(true)
                             .is_some_and(|pointee_ty| has_ptr_meta(fx.tcx, pointee_ty))
                     }
 
-                    if is_fat_ptr(fx, from_ty) {
-                        if is_fat_ptr(fx, to_ty) {
-                            // fat-ptr -> fat-ptr
+                    if is_wide_ptr(fx, from_ty) {
+                        if is_wide_ptr(fx, to_ty) {
+                            // wide-ptr -> wide-ptr
                             lval.write_cvalue(fx, operand.cast_pointer_to(dest_layout));
                         } else {
-                            // fat-ptr -> thin-ptr
+                            // wide-ptr -> thin-ptr
                             let (ptr, _extra) = operand.load_scalar_pair(fx);
                             lval.write_cvalue(fx, CValue::by_val(ptr, dest_layout))
                         }

compiler/rustc_codegen_cranelift/src/common.rs

@@ -101,7 +101,7 @@ fn clif_pair_type_from_ty<'tcx>(
     })
 }
 
-/// Is a pointer to this type a fat ptr?
+/// Is a pointer to this type a wide ptr?
 pub(crate) fn has_ptr_meta<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool {
     if ty.is_sized(tcx, ParamEnv::reveal_all()) {
         return false;

compiler/rustc_codegen_cranelift/src/debuginfo/types.rs

@@ -139,7 +139,7 @@ impl DebugContext {
 
             pointer_type_id
         } else {
-            // FIXME implement debuginfo for fat pointers
+            // FIXME implement debuginfo for wide pointers
             self.placeholder_for_type(tcx, type_dbg, ptr_type)
         }
     }

compiler/rustc_codegen_gcc/src/intrinsic/simd.rs

@@ -478,7 +478,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                 let metadata = p_ty.ptr_metadata_ty(bx.tcx, |ty| {
                     bx.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), ty)
                 });
-                require!(metadata.is_unit(), InvalidMonomorphization::CastFatPointer {
+                require!(metadata.is_unit(), InvalidMonomorphization::CastWidePointer {
                     span,
                     name,
                     ty: in_elem
@@ -493,7 +493,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                 let metadata = p_ty.ptr_metadata_ty(bx.tcx, |ty| {
                     bx.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), ty)
                 });
-                require!(metadata.is_unit(), InvalidMonomorphization::CastFatPointer {
+                require!(metadata.is_unit(), InvalidMonomorphization::CastWidePointer {
                     span,
                     name,
                     ty: out_elem

compiler/rustc_codegen_gcc/src/type_of.rs

@@ -207,7 +207,7 @@ impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> {
         // layout.
         if let Abi::Scalar(ref scalar) = self.abi {
             // Use a different cache for scalars because pointers to DSTs
-            // can be either fat or thin (data pointers of fat pointers).
+            // can be either wide or thin (data pointers of wide pointers).
             if let Some(&ty) = cx.scalar_types.borrow().get(&self.ty) {
                 return ty;
             }

compiler/rustc_codegen_llvm/src/abi.rs

@@ -7,7 +7,7 @@ use rustc_codegen_ssa::mir::place::{PlaceRef, PlaceValue};
 use rustc_codegen_ssa::traits::*;
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::LayoutOf;
-pub(crate) use rustc_middle::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
+pub(crate) use rustc_middle::ty::layout::{WIDE_PTR_ADDR, WIDE_PTR_EXTRA};
 use rustc_middle::{bug, ty};
 use rustc_session::config;
 pub(crate) use rustc_target::abi::call::*;

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -34,7 +34,7 @@ use super::utils::{
 };
 use crate::common::CodegenCx;
 use crate::debuginfo::metadata::type_map::build_type_with_children;
-use crate::debuginfo::utils::{FatPtrKind, fat_pointer_kind};
+use crate::debuginfo::utils::{WidePtrKind, wide_pointer_kind};
 use crate::llvm::debuginfo::{
     DIDescriptor, DIFile, DIFlags, DILexicalBlock, DIScope, DIType, DebugEmissionKind,
     DebugNameTableKind,
@@ -161,7 +161,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
     unique_type_id: UniqueTypeId<'tcx>,
 ) -> DINodeCreationResult<'ll> {
     // The debuginfo generated by this function is only valid if `ptr_type` is really just
-    // a (fat) pointer. Make sure it is not called for e.g. `Box<T, NonZSTAllocator>`.
+    // a (wide) pointer. Make sure it is not called for e.g. `Box<T, NonZSTAllocator>`.
     assert_eq!(
         cx.size_and_align_of(ptr_type),
         cx.size_and_align_of(Ty::new_mut_ptr(cx.tcx, pointee_type))
@@ -174,7 +174,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
     let data_layout = &cx.tcx.data_layout;
     let ptr_type_debuginfo_name = compute_debuginfo_type_name(cx.tcx, ptr_type, true);
 
-    match fat_pointer_kind(cx, pointee_type) {
+    match wide_pointer_kind(cx, pointee_type) {
         None => {
             // This is a thin pointer. Create a regular pointer type and give it the correct name.
             assert_eq!(
@@ -197,7 +197,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
 
             DINodeCreationResult { di_node, already_stored_in_typemap: false }
         }
-        Some(fat_pointer_kind) => {
+        Some(wide_pointer_kind) => {
             type_map::build_type_with_children(
                 cx,
                 type_map::stub(
@@ -210,7 +210,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
                     DIFlags::FlagZero,
                 ),
                 |cx, owner| {
-                    // FIXME: If this fat pointer is a `Box` then we don't want to use its
+                    // FIXME: If this wide pointer is a `Box` then we don't want to use its
                     //        type layout and instead use the layout of the raw pointer inside
                     //        of it.
                     //        The proper way to handle this is to not treat Box as a pointer
@@ -227,16 +227,16 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
                     };
 
                     let layout = cx.layout_of(layout_type);
-                    let addr_field = layout.field(cx, abi::FAT_PTR_ADDR);
-                    let extra_field = layout.field(cx, abi::FAT_PTR_EXTRA);
+                    let addr_field = layout.field(cx, abi::WIDE_PTR_ADDR);
+                    let extra_field = layout.field(cx, abi::WIDE_PTR_EXTRA);
 
-                    let (addr_field_name, extra_field_name) = match fat_pointer_kind {
-                        FatPtrKind::Dyn => ("pointer", "vtable"),
-                        FatPtrKind::Slice => ("data_ptr", "length"),
+                    let (addr_field_name, extra_field_name) = match wide_pointer_kind {
+                        WidePtrKind::Dyn => ("pointer", "vtable"),
+                        WidePtrKind::Slice => ("data_ptr", "length"),
                     };
 
-                    assert_eq!(abi::FAT_PTR_ADDR, 0);
-                    assert_eq!(abi::FAT_PTR_EXTRA, 1);
+                    assert_eq!(abi::WIDE_PTR_ADDR, 0);
+                    assert_eq!(abi::WIDE_PTR_EXTRA, 1);
 
                     // The data pointer type is a regular, thin pointer, regardless of whether this
                     // is a slice or a trait object.
@@ -258,7 +258,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
                             owner,
                             addr_field_name,
                             (addr_field.size, addr_field.align.abi),
-                            layout.fields.offset(abi::FAT_PTR_ADDR),
+                            layout.fields.offset(abi::WIDE_PTR_ADDR),
                             DIFlags::FlagZero,
                             data_ptr_type_di_node,
                         ),
@@ -267,7 +267,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
                             owner,
                             extra_field_name,
                             (extra_field.size, extra_field.align.abi),
-                            layout.fields.offset(abi::FAT_PTR_EXTRA),
+                            layout.fields.offset(abi::WIDE_PTR_EXTRA),
                             DIFlags::FlagZero,
                             type_di_node(cx, extra_field.ty),
                         ),
@@ -391,7 +391,7 @@ fn build_dyn_type_di_node<'ll, 'tcx>(
 ///
 /// NOTE: We currently emit just emit the debuginfo for the element type here
 /// (i.e. `T` for slices and `u8` for `str`), so that we end up with
-/// `*const T` for the `data_ptr` field of the corresponding fat-pointer
+/// `*const T` for the `data_ptr` field of the corresponding wide-pointer
 /// debuginfo of `&[T]`.
 ///
 /// It would be preferable and more accurate if we emitted a DIArray of T

compiler/rustc_codegen_llvm/src/debuginfo/utils.rs

@@ -49,23 +49,23 @@ pub(crate) fn get_namespace_for_item<'ll>(cx: &CodegenCx<'ll, '_>, def_id: DefId
 }
 
 #[derive(Debug, PartialEq, Eq)]
-pub(crate) enum FatPtrKind {
+pub(crate) enum WidePtrKind {
     Slice,
     Dyn,
 }
 
 /// Determines if `pointee_ty` is slice-like or trait-object-like, i.e.
-/// if the second field of the fat pointer is a length or a vtable-pointer.
-/// If `pointee_ty` does not require a fat pointer (because it is Sized) then
+/// if the second field of the wide pointer is a length or a vtable-pointer.
+/// If `pointee_ty` does not require a wide pointer (because it is Sized) then
 /// the function returns `None`.
-pub(crate) fn fat_pointer_kind<'ll, 'tcx>(
+pub(crate) fn wide_pointer_kind<'ll, 'tcx>(
     cx: &CodegenCx<'ll, 'tcx>,
     pointee_ty: Ty<'tcx>,
-) -> Option<FatPtrKind> {
+) -> Option<WidePtrKind> {
     let pointee_tail_ty = cx.tcx.struct_tail_for_codegen(pointee_ty, cx.param_env());
     let layout = cx.layout_of(pointee_tail_ty);
     trace!(
-        "fat_pointer_kind: {:?} has layout {:?} (is_unsized? {})",
+        "wide_pointer_kind: {:?} has layout {:?} (is_unsized? {})",
         pointee_tail_ty,
         layout,
         layout.is_unsized()
@@ -76,8 +76,8 @@ pub(crate) fn fat_pointer_kind<'ll, 'tcx>(
     }
 
     match *pointee_tail_ty.kind() {
-        ty::Str | ty::Slice(_) => Some(FatPtrKind::Slice),
-        ty::Dynamic(..) => Some(FatPtrKind::Dyn),
+        ty::Str | ty::Slice(_) => Some(WidePtrKind::Slice),
+        ty::Dynamic(..) => Some(WidePtrKind::Dyn),
         ty::Foreign(_) => {
             // Assert that pointers to foreign types really are thin:
             assert_eq!(
@@ -90,7 +90,7 @@ pub(crate) fn fat_pointer_kind<'ll, 'tcx>(
             // For all other pointee types we should already have returned None
             // at the beginning of the function.
             panic!(
-                "fat_pointer_kind() - Encountered unexpected `pointee_tail_ty`: {pointee_tail_ty:?}"
+                "wide_pointer_kind() - Encountered unexpected `pointee_tail_ty`: {pointee_tail_ty:?}"
             )
         }
     }

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -2185,7 +2185,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
                 let metadata = p_ty.ptr_metadata_ty(bx.tcx, |ty| {
                     bx.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), ty)
                 });
-                require!(metadata.is_unit(), InvalidMonomorphization::CastFatPointer {
+                require!(metadata.is_unit(), InvalidMonomorphization::CastWidePointer {
                     span,
                     name,
                     ty: in_elem
@@ -2200,7 +2200,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
                 let metadata = p_ty.ptr_metadata_ty(bx.tcx, |ty| {
                     bx.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), ty)
                 });
-                require!(metadata.is_unit(), InvalidMonomorphization::CastFatPointer {
+                require!(metadata.is_unit(), InvalidMonomorphization::CastWidePointer {
                     span,
                     name,
                     ty: out_elem