From 478f8287c0e2c35cda511fd3ac01b7ac78ee7cfe Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Mon, 2 Jun 2025 08:59:29 +1000 Subject: Introduce `ByteSymbol`. It's like `Symbol` but for byte strings. The interner is now used for both `Symbol` and `ByteSymbol`. E.g. if you intern `"dog"` and `b"dog"` you'll get a `Symbol` and a `ByteSymbol` with the same index and the characters will only be stored once. The motivation for this is to eliminate the `Arc`s in `ast::LitKind`, to make `ast::LitKind` impl `Copy`, and to avoid the need to arena-allocate `ast::LitKind` in HIR. The latter change reduces peak memory by a non-trivial amount on literal-heavy benchmarks such as `deep-vector` and `tuple-stress`. `Encoder`, `Decoder`, `SpanEncoder`, and `SpanDecoder` all get some changes so that they can handle normal strings and byte strings. This change does slow down compilation of programs that use `include_bytes!` on large files, because the contents of those files are now interned (hashed). This makes `include_bytes!` more similar to `include_str!`, though `include_bytes!` contents still aren't escaped, and hashing is still much cheaper than escaping. --- compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'compiler/rustc_hir_analysis') diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs index 74739355e1f..55bf2ab6b50 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs @@ -2364,9 +2364,9 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { }; let lit_input = match expr.kind { - hir::ExprKind::Lit(lit) => Some(LitToConstInput { lit: &lit.node, ty, neg: false }), + hir::ExprKind::Lit(lit) => Some(LitToConstInput { lit: lit.node, ty, neg: false }), hir::ExprKind::Unary(hir::UnOp::Neg, expr) => match expr.kind { - hir::ExprKind::Lit(lit) => Some(LitToConstInput { lit: &lit.node, ty, neg: true }), + hir::ExprKind::Lit(lit) => Some(LitToConstInput { lit: lit.node, ty, neg: true }), _ => None, }, _ => None, -- cgit 1.4.1-3-g733a5