diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/lib.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/intrinsic.rs | 22 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/operand.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/place.rs | 23 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/size_of_val.rs (renamed from compiler/rustc_codegen_ssa/src/glue.rs) | 36 |
5 files changed, 53 insertions, 36 deletions
diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs index cd5eb77e06e..9b60f0844a0 100644 --- a/compiler/rustc_codegen_ssa/src/lib.rs +++ b/compiler/rustc_codegen_ssa/src/lib.rs @@ -51,10 +51,10 @@ pub mod codegen_attrs; pub mod common; pub mod debuginfo; pub mod errors; -pub mod glue; pub mod meth; pub mod mir; pub mod mono_item; +pub mod size_of_val; pub mod target_features; pub mod traits; diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs index 136d06d561a..a5bffc33d39 100644 --- a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs +++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs @@ -4,8 +4,8 @@ use super::FunctionCx; use crate::common::IntPredicate; use crate::errors; use crate::errors::InvalidMonomorphization; -use crate::glue; use crate::meth; +use crate::size_of_val; use crate::traits::*; use crate::MemFlags; @@ -88,21 +88,17 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { sym::va_end => bx.va_end(args[0].immediate()), sym::size_of_val => { let tp_ty = fn_args.type_at(0); - if let OperandValue::Pair(_, meta) = args[0].val { - let (llsize, _) = glue::size_and_align_of_dst(bx, tp_ty, Some(meta)); - llsize - } else { - bx.const_usize(bx.layout_of(tp_ty).size.bytes()) - } + let meta = + if let OperandValue::Pair(_, meta) = args[0].val { Some(meta) } else { None }; + let (llsize, _) = size_of_val::size_and_align_of_dst(bx, tp_ty, meta); + llsize } sym::min_align_of_val => { let tp_ty = fn_args.type_at(0); - if let OperandValue::Pair(_, meta) = args[0].val { - let (_, llalign) = glue::size_and_align_of_dst(bx, tp_ty, Some(meta)); - llalign - } else { - bx.const_usize(bx.layout_of(tp_ty).align.abi.bytes()) - } + let meta = + if let OperandValue::Pair(_, meta) = args[0].val { Some(meta) } else { None }; + let (_, llalign) = size_of_val::size_and_align_of_dst(bx, tp_ty, meta); + llalign } sym::vtable_size | sym::vtable_align => { let vtable = args[0].immediate(); diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs index feee3ac03d0..e8c58f6b6f8 100644 --- a/compiler/rustc_codegen_ssa/src/mir/operand.rs +++ b/compiler/rustc_codegen_ssa/src/mir/operand.rs @@ -2,7 +2,7 @@ use super::place::PlaceRef; use super::{FunctionCx, LocalRef}; use crate::base; -use crate::glue; +use crate::size_of_val; use crate::traits::*; use crate::MemFlags; @@ -466,13 +466,13 @@ impl<'a, 'tcx, V: CodegenObject> OperandValue<V> { .ty; let OperandValue::Ref(llptr, Some(llextra), _) = self else { - bug!("store_unsized called with a sized value") + bug!("store_unsized called with a sized value (or with an extern type)") }; // Allocate an appropriate region on the stack, and copy the value into it. Since alloca // doesn't support dynamic alignment, we allocate an extra align - 1 bytes, and align the // pointer manually. - let (size, align) = glue::size_and_align_of_dst(bx, unsized_ty, Some(llextra)); + let (size, align) = size_of_val::size_and_align_of_dst(bx, unsized_ty, Some(llextra)); let one = bx.const_usize(1); let align_minus_1 = bx.sub(align, one); let size_extra = bx.add(size, align_minus_1); diff --git a/compiler/rustc_codegen_ssa/src/mir/place.rs b/compiler/rustc_codegen_ssa/src/mir/place.rs index 83425dee1a8..c0bb3ac5661 100644 --- a/compiler/rustc_codegen_ssa/src/mir/place.rs +++ b/compiler/rustc_codegen_ssa/src/mir/place.rs @@ -2,7 +2,7 @@ use super::operand::OperandValue; use super::{FunctionCx, LocalRef}; use crate::common::IntPredicate; -use crate::glue; +use crate::size_of_val; use crate::traits::*; use rustc_middle::mir; @@ -99,6 +99,8 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { let offset = self.layout.fields.offset(ix); let effective_field_align = self.align.restrict_for_offset(offset); + // `simple` is called when we don't need to adjust the offset to + // the dynamic alignment of the field. let mut simple = || { let llval = match self.layout.abi { _ if offset.bytes() == 0 => { @@ -141,28 +143,21 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { }; // Simple cases, which don't need DST adjustment: - // * no metadata available - just log the case - // * known alignment - sized types, `[T]`, `str` or a foreign type + // * known alignment - sized types, `[T]`, `str` + // * offset 0 -- rounding up to alignment cannot change the offset // Note that looking at `field.align` is incorrect since that is not necessarily equal // to the dynamic alignment of the type. match field.ty.kind() { - _ if self.llextra.is_none() => { - debug!( - "unsized field `{}`, of `{:?}` has no metadata for adjustment", - ix, self.llval - ); - return simple(); - } _ if field.is_sized() => return simple(), - ty::Slice(..) | ty::Str | ty::Foreign(..) => return simple(), + ty::Slice(..) | ty::Str => return simple(), + _ if offset.bytes() == 0 => return simple(), _ => {} } // We need to get the pointer manually now. // We do this by casting to a `*i8`, then offsetting it by the appropriate amount. // We do this instead of, say, simply adjusting the pointer from the result of a GEP - // because the field may have an arbitrary alignment in the LLVM representation - // anyway. + // because the field may have an arbitrary alignment in the LLVM representation. // // To demonstrate: // @@ -179,7 +174,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> { let unaligned_offset = bx.cx().const_usize(offset.bytes()); // Get the alignment of the field - let (_, mut unsized_align) = glue::size_and_align_of_dst(bx, field.ty, meta); + let (_, mut unsized_align) = size_of_val::size_and_align_of_dst(bx, field.ty, meta); // For packed types, we need to cap alignment. if let ty::Adt(def, _) = self.layout.ty.kind() diff --git a/compiler/rustc_codegen_ssa/src/glue.rs b/compiler/rustc_codegen_ssa/src/size_of_val.rs index c34f1dbf856..b8a4949d59f 100644 --- a/compiler/rustc_codegen_ssa/src/glue.rs +++ b/compiler/rustc_codegen_ssa/src/size_of_val.rs @@ -1,10 +1,11 @@ -//! -// -// Code relating to drop glue. +//! Computing the size and alignment of a value. +use crate::common; use crate::common::IntPredicate; use crate::meth; use crate::traits::*; +use rustc_hir::LangItem; +use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; use rustc_middle::ty::{self, Ty}; use rustc_target::abi::WrappingRange; @@ -14,7 +15,7 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( info: Option<Bx::Value>, ) -> (Bx::Value, Bx::Value) { let layout = bx.layout_of(t); - debug!("size_and_align_of_dst(ty={}, info={:?}): layout: {:?}", t, info, layout); + trace!("size_and_align_of_dst(ty={}, info={:?}): layout: {:?}", t, info, layout); if layout.is_sized() { let size = bx.const_usize(layout.size.bytes()); let align = bx.const_usize(layout.align.abi.bytes()); @@ -51,7 +52,31 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( bx.const_usize(unit.align.abi.bytes()), ) } - _ => { + ty::Foreign(_) => { + // `extern` type. We cannot compute the size, so panic. + let msg_str = with_no_visible_paths!({ + with_no_trimmed_paths!({ + format!("attempted to compute the size or alignment of extern type `{t}`") + }) + }); + let msg = bx.const_str(&msg_str); + + // Obtain the panic entry point. + let (fn_abi, llfn) = 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.) + let fn_ty = bx.fn_decl_backend_type(fn_abi); + + bx.call(fn_ty, /* fn_attrs */ None, Some(fn_abi), llfn, &[msg.0, msg.1], None); + + // This function does not return so we can now return whatever we want. + let size = bx.const_usize(layout.size.bytes()); + let align = bx.const_usize(layout.align.abi.bytes()); + (size, align) + } + ty::Adt(..) | ty::Tuple(..) => { // First get the size of all statically known fields. // Don't use size_of because it also rounds up to alignment, which we // want to avoid, as the unsized field's alignment could be smaller. @@ -122,5 +147,6 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( (size, align) } + _ => bug!("size_and_align_of_dst: {t} not supported"), } } |