Clean up formatting.

Reflow overly long comments, plus some minor whitespace improvements.

Author: nnethercote

compiler/rustc_codegen_ssa/src/base.rs

@@ -154,7 +154,8 @@ fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             let old_info =
                 old_info.expect("unsized_info: missing old info for trait upcasting coercion");
             if data_a.principal_def_id() == data_b.principal_def_id() {
-                // A NOP cast that doesn't actually change anything, should be allowed even with invalid vtables.
+                // A NOP cast that doesn't actually change anything, should be allowed even with
+                // invalid vtables.
                 return old_info;
             }
 
@@ -985,7 +986,8 @@ impl CrateInfo {
                 false
             }
             CrateType::Staticlib | CrateType::Rlib => {
-                // We don't invoke the linker for these, so we don't need to collect the NatVis for them.
+                // We don't invoke the linker for these, so we don't need to collect the NatVis for
+                // them.
                 false
             }
         });

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -317,9 +317,9 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                                 "extern mutable statics are not allowed with `#[linkage]`",
                             );
                             diag.note(
-                                "marking the extern static mutable would allow changing which symbol \
-                                 the static references rather than make the target of the symbol \
-                                 mutable",
+                                "marking the extern static mutable would allow changing which \
+                                 symbol the static references rather than make the target of the \
+                                 symbol mutable",
                             );
                             diag.emit();
                         }
@@ -711,18 +711,19 @@ fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option<u16> {
     if let Some(MetaItemLit { kind: LitKind::Int(ordinal, LitIntType::Unsuffixed), .. }) =
         sole_meta_list
     {
-        // According to the table at https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#import-header,
-        // the ordinal must fit into 16 bits. Similarly, the Ordinal field in COFFShortExport (defined
-        // in llvm/include/llvm/Object/COFFImportFile.h), which we use to communicate import information
-        // to LLVM for `#[link(kind = "raw-dylib"_])`, is also defined to be uint16_t.
+        // According to the table at
+        // https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#import-header, the
+        // ordinal must fit into 16 bits. Similarly, the Ordinal field in COFFShortExport (defined
+        // in llvm/include/llvm/Object/COFFImportFile.h), which we use to communicate import
+        // information to LLVM for `#[link(kind = "raw-dylib"_])`, is also defined to be uint16_t.
         //
-        // FIXME: should we allow an ordinal of 0?  The MSVC toolchain has inconsistent support for this:
-        // both LINK.EXE and LIB.EXE signal errors and abort when given a .DEF file that specifies
-        // a zero ordinal. However, llvm-dlltool is perfectly happy to generate an import library
-        // for such a .DEF file, and MSVC's LINK.EXE is also perfectly happy to consume an import
-        // library produced by LLVM with an ordinal of 0, and it generates an .EXE.  (I don't know yet
-        // if the resulting EXE runs, as I haven't yet built the necessary DLL -- see earlier comment
-        // about LINK.EXE failing.)
+        // FIXME: should we allow an ordinal of 0?  The MSVC toolchain has inconsistent support for
+        // this: both LINK.EXE and LIB.EXE signal errors and abort when given a .DEF file that
+        // specifies a zero ordinal. However, llvm-dlltool is perfectly happy to generate an import
+        // library for such a .DEF file, and MSVC's LINK.EXE is also perfectly happy to consume an
+        // import library produced by LLVM with an ordinal of 0, and it generates an .EXE.  (I
+        // don't know yet if the resulting EXE runs, as I haven't yet built the necessary DLL --
+        // see earlier comment about LINK.EXE failing.)
         if *ordinal <= u16::MAX as u128 {
             Some(ordinal.get() as u16)
         } else {

compiler/rustc_codegen_ssa/src/common.rs

@@ -200,7 +200,8 @@ pub fn i686_decorated_name(
     let mut decorated_name = String::with_capacity(name.len() + 6);
 
     if disable_name_mangling {
-        // LLVM uses a binary 1 ('\x01') prefix to a name to indicate that mangling needs to be disabled.
+        // LLVM uses a binary 1 ('\x01') prefix to a name to indicate that mangling needs to be
+        // disabled.
         decorated_name.push('\x01');
     }
 

compiler/rustc_codegen_ssa/src/debuginfo/mod.rs

@@ -76,9 +76,9 @@ fn tag_base_type_opt<'tcx>(
                     Primitive::Float(f) => Integer::from_size(f.size()).unwrap(),
                     // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
                     Primitive::Pointer(_) => {
-                        // If the niche is the NULL value of a reference, then `discr_enum_ty` will be
-                        // a RawPtr. CodeView doesn't know what to do with enums whose base type is a
-                        // pointer so we fix this up to just be `usize`.
+                        // If the niche is the NULL value of a reference, then `discr_enum_ty` will
+                        // be a RawPtr. CodeView doesn't know what to do with enums whose base type
+                        // is a pointer so we fix this up to just be `usize`.
                         // DWARF might be able to deal with this but with an integer type we are on
                         // the safe side there too.
                         tcx.data_layout.ptr_sized_integer()

compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs

@@ -95,7 +95,8 @@ fn push_debuginfo_type_name<'tcx>(
                     }
                     Err(e) => {
                         // Computing the layout can still fail here, e.g. if the target architecture
-                        // cannot represent the type. See https://github.com/rust-lang/rust/issues/94961.
+                        // cannot represent the type. See
+                        // https://github.com/rust-lang/rust/issues/94961.
                         tcx.dcx().emit_fatal(e.into_diagnostic());
                     }
                 }

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -996,17 +996,18 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         // To get a `*mut RcBox<Self>`, we just keep unwrapping newtypes until
                         // we get a value of a built-in pointer type.
                         //
-                        // This is also relevant for `Pin<&mut Self>`, where we need to peel the `Pin`.
+                        // This is also relevant for `Pin<&mut Self>`, where we need to peel the
+                        // `Pin`.
                         while !op.layout.ty.is_unsafe_ptr() && !op.layout.ty.is_ref() {
                             let (idx, _) = op.layout.non_1zst_field(bx).expect(
                                 "not exactly one non-1-ZST field in a `DispatchFromDyn` type",
                             );
                             op = op.extract_field(bx, idx);
                         }
 
-                        // now that we have `*dyn Trait` or `&dyn Trait`, split it up into its
+                        // Now that we have `*dyn Trait` or `&dyn Trait`, split it up into its
                         // data pointer and vtable. Look up the method in the vtable, and pass
-                        // the data pointer as the first argument
+                        // the data pointer as the first argument.
                         llfn = Some(meth::VirtualIndex::from_index(idx).get_fn(
                             bx,
                             meta,
@@ -1440,8 +1441,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         let (mut llval, align, by_ref) = match op.val {
             Immediate(_) | Pair(..) => match arg.mode {
                 PassMode::Indirect { attrs, .. } => {
-                    // Indirect argument may have higher alignment requirements than the type's alignment.
-                    // This can happen, e.g. when passing types with <4 byte alignment on the stack on x86.
+                    // Indirect argument may have higher alignment requirements than the type's
+                    // alignment. This can happen, e.g. when passing types with <4 byte alignment
+                    // on the stack on x86.
                     let required_align = match attrs.pointee_align {
                         Some(pointee_align) => cmp::max(pointee_align, arg.layout.align.abi),
                         None => arg.layout.align.abi,

compiler/rustc_codegen_ssa/src/mir/constant.rs

@@ -32,27 +32,28 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     /// that the given `constant` is an `Const::Unevaluated` and must be convertible to
     /// a `ValTree`. If you want a more general version of this, talk to `wg-const-eval` on zulip.
     ///
-    /// Note that this function is cursed, since usually MIR consts should not be evaluated to valtrees!
+    /// Note that this function is cursed, since usually MIR consts should not be evaluated to
+    /// valtrees!
     fn eval_unevaluated_mir_constant_to_valtree(
         &self,
         constant: &mir::ConstOperand<'tcx>,
     ) -> Result<Result<ty::ValTree<'tcx>, Ty<'tcx>>, ErrorHandled> {
         let uv = match self.monomorphize(constant.const_) {
             mir::Const::Unevaluated(uv, _) => uv.shrink(),
             mir::Const::Ty(_, c) => match c.kind() {
-                // A constant that came from a const generic but was then used as an argument to old-style
-                // simd_shuffle (passing as argument instead of as a generic param).
+                // A constant that came from a const generic but was then used as an argument to
+                // old-style simd_shuffle (passing as argument instead of as a generic param).
                 rustc_type_ir::ConstKind::Value(_, valtree) => return Ok(Ok(valtree)),
                 other => span_bug!(constant.span, "{other:#?}"),
             },
             // We should never encounter `Const::Val` unless MIR opts (like const prop) evaluate
-            // a constant and write that value back into `Operand`s. This could happen, but is unlikely.
-            // Also: all users of `simd_shuffle` are on unstable and already need to take a lot of care
-            // around intrinsics. For an issue to happen here, it would require a macro expanding to a
-            // `simd_shuffle` call without wrapping the constant argument in a `const {}` block, but
-            // the user pass through arbitrary expressions.
-            // FIXME(oli-obk): replace the magic const generic argument of `simd_shuffle` with a real
-            // const generic, and get rid of this entire function.
+            // a constant and write that value back into `Operand`s. This could happen, but is
+            // unlikely. Also: all users of `simd_shuffle` are on unstable and already need to take
+            // a lot of care around intrinsics. For an issue to happen here, it would require a
+            // macro expanding to a `simd_shuffle` call without wrapping the constant argument in a
+            // `const {}` block, but the user pass through arbitrary expressions.
+            // FIXME(oli-obk): replace the magic const generic argument of `simd_shuffle` with a
+            // real const generic, and get rid of this entire function.
             other => span_bug!(constant.span, "{other:#?}"),
         };
         let uv = self.monomorphize(uv);

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -24,6 +24,7 @@ pub struct FunctionDebugContext<'tcx, S, L> {
     /// Maps from an inlined function to its debug info declaration.
     pub inlined_function_scopes: FxHashMap<Instance<'tcx>, S>,
 }
+
 #[derive(Copy, Clone)]
 pub enum VariableKind {
     ArgumentVariable(usize /*index*/),

compiler/rustc_codegen_ssa/src/mir/operand.rs

@@ -478,8 +478,8 @@ impl<'a, 'tcx, V: CodegenObject> OperandValue<V> {
         debug!("OperandRef::store: operand={:?}, dest={:?}", self, dest);
         match self {
             OperandValue::ZeroSized => {
-                // Avoid generating stores of zero-sized values, because the only way to have a zero-sized
-                // value is through `undef`/`poison`, and the store itself is useless.
+                // Avoid generating stores of zero-sized values, because the only way to have a
+                // zero-sized value is through `undef`/`poison`, and the store itself is useless.
             }
             OperandValue::Ref(val) => {
                 assert!(dest.layout.is_sized(), "cannot directly store unsized values");

compiler/rustc_codegen_ssa/src/size_of_val.rs

@@ -45,11 +45,13 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             // The info in this case is the length of the str, so the size is that
             // times the unit size.
             (
-                // All slice sizes must fit into `isize`, so this multiplication cannot (signed) wrap.
+                // All slice sizes must fit into `isize`, so this multiplication cannot (signed)
+                // wrap.
                 // NOTE: ideally, we want the effects of both `unchecked_smul` and `unchecked_umul`
                 // (resulting in `mul nsw nuw` in LLVM IR), since we know that the multiplication
-                // cannot signed wrap, and that both operands are non-negative. But at the time of writing,
-                // the `LLVM-C` binding can't do this, and it doesn't seem to enable any further optimizations.
+                // cannot signed wrap, and that both operands are non-negative. But at the time of
+                // writing, the `LLVM-C` binding can't do this, and it doesn't seem to enable any
+                // further optimizations.
                 bx.unchecked_smul(info.unwrap(), bx.const_usize(unit.size.bytes())),
                 bx.const_usize(unit.align.abi.bytes()),
             )
@@ -67,9 +69,9 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             let (fn_abi, llfn, _instance) =
                 common::build_langcall(bx, None, LangItem::PanicNounwind);
 
-            // Generate the call.
-            // Cannot use `do_call` since we don't have a MIR terminator so we can't create a `TerminationCodegenHelper`.
-            // (But we are in good company, this code is duplicated plenty of times.)
+            // Generate the call. Cannot use `do_call` since we don't have a MIR terminator so we
+            // can't create a `TerminationCodegenHelper`. (But we are in good company, this code is
+            // duplicated plenty of times.)
             let fn_ty = bx.fn_decl_backend_type(fn_abi);
 
             bx.call(
@@ -148,9 +150,14 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             // The full formula for the size would be:
             // let unsized_offset_adjusted = unsized_offset_unadjusted.align_to(unsized_align);
             // let full_size = (unsized_offset_adjusted + unsized_size).align_to(full_align);
-            // However, `unsized_size` is a multiple of `unsized_align`.
-            // Therefore, we can equivalently do the `align_to(unsized_align)` *after* adding `unsized_size`:
-            // let full_size = (unsized_offset_unadjusted + unsized_size).align_to(unsized_align).align_to(full_align);
+            // However, `unsized_size` is a multiple of `unsized_align`. Therefore, we can
+            // equivalently do the `align_to(unsized_align)` *after* adding `unsized_size`:
+            //
+            // let full_size =
+            //     (unsized_offset_unadjusted + unsized_size)
+            //     .align_to(unsized_align)
+            //     .align_to(full_align);
+            //
             // Furthermore, `align >= unsized_align`, and therefore we only need to do:
             // let full_size = (unsized_offset_unadjusted + unsized_size).align_to(full_align);