Commit d9d8e78

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built-in derive: remove BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE hack and lint

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-48

lines changed

compiler/rustc_builtin_macros/src/deriving/generic
- mod.rs

1 file changed

-48

lines changed

`‎compiler/rustc_builtin_macros/src/deriving/generic/mod.rs‎`

Lines changed: 6 additions & 48 deletions

Original file line number	Diff line number	Diff line change
`@@ -181,11 +181,10 @@ use crate::{deriving, errors};`
`181`	`181`	`use rustc_ast::ptr::P;`
`182`	`182`	`use rustc_ast::{`
`183`	`183`	`self as ast, BindingMode, ByRef, EnumDef, Expr, GenericArg, GenericParamKind, Generics,`
`184`		`- Mutability, PatKind, TyKind,VariantData,`
	`184`	`+ Mutability, PatKind, VariantData,`
`185`	`185`	`};`
`186`	`186`	`use rustc_attr as attr;`
`187`	`187`	`use rustc_expand::base::{Annotatable, ExtCtxt};`
`188`		`-use rustc_session::lint::builtin::BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE;`
`189`	`188`	`use rustc_span::symbol::{kw, sym, Ident, Symbol};`
`190`	`189`	`use rustc_span::{Span, DUMMY_SP};`
`191`	`190`	`use std::cell::RefCell;`
`@@ -1599,52 +1598,11 @@ impl<'a> TraitDef<'a> {`
`1599`	`1598`	`),`
`1600`	`1599`	`);`
`1601`	`1600`	`if is_packed {`
`1602`		`- // In general, fields in packed structs are copied via a`
`1603`		- // block, e.g. `&{self.0}`. The two exceptions are `[u8]`
`1604`		- // and `str` fields, which cannot be copied and also never
`1605`		`- // cause unaligned references. These exceptions are allowed`
`1606`		- // to handle the `FlexZeroSlice` type in the `zerovec`
`1607`		- // crate within `icu4x-0.9.0`.
`1608`		`- //`
`1609`		- // Once use of `icu4x-0.9.0` has dropped sufficiently, this
`1610`		`- // exception should be removed.`
`1611`		`- let is_simple_path = \|ty: &P<ast::Ty>, sym\| {`
`1612`		`- if let TyKind::Path(None, ast::Path { segments, .. }) = &ty.kind`
`1613`		`- && let [seg] = segments.as_slice()`
`1614`		`- && seg.ident.name == sym`
`1615`		`- && seg.args.is_none()`
`1616`		`- {`
`1617`		`- true`
`1618`		`- } else {`
`1619`		`- false`
`1620`		`- }`
`1621`		`- };`
`1622`		`-`
`1623`		`- let exception = if let TyKind::Slice(ty) = &struct_field.ty.kind`
`1624`		`- && is_simple_path(ty, sym::u8)`
`1625`		`- {`
`1626`		`- Some("byte")`
`1627`		`- } else if is_simple_path(&struct_field.ty, sym::str) {`
`1628`		`- Some("string")`
`1629`		`- } else {`
`1630`		`- None`
`1631`		`- };`
`1632`		`-`
`1633`		`- if let Some(ty) = exception {`
`1634`		`- cx.sess.psess.buffer_lint(`
`1635`		`- BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE,`
`1636`		`- sp,`
`1637`		`- ast::CRATE_NODE_ID,`
`1638`		`- rustc_lint_defs::BuiltinLintDiag::ByteSliceInPackedStructWithDerive {`
`1639`		`- ty: ty.to_string(),`
`1640`		`- },`
`1641`		`- );`
`1642`		`- } else {`
`1643`		- // Wrap the expression in `{...}`, causing a copy.
`1644`		`- field_expr = cx.expr_block(`
`1645`		`- cx.block(struct_field.span, thin_vec![cx.stmt_expr(field_expr)]),`
`1646`		`- );`
`1647`		`- }`
	`1601`	+ // Fields in packed structs are wrapped in a block, e.g. `&{self.0}`,
	`1602`	`+ // causing a copy instead of a (potentially misaligned) reference.`
	`1603`	`+ field_expr = cx.expr_block(`
	`1604`	`+ cx.block(struct_field.span, thin_vec![cx.stmt_expr(field_expr)]),`
	`1605`	`+ );`
`1648`	`1606`	`}`
`1649`	`1607`	`cx.expr_addr_of(sp, field_expr)`
`1650`	`1608`	`})`

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Commit d9d8e78

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`‎compiler/rustc_builtin_macros/src/deriving/generic/mod.rs‎`

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