From 79b11f0802a17f5fce65e22b4934104d40a10e93 Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Tue, 19 Sep 2023 17:08:13 +1000 Subject: [PATCH] rustc_arena: tweak some comments. --- compiler/rustc_arena/src/lib.rs | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/compiler/rustc_arena/src/lib.rs b/compiler/rustc_arena/src/lib.rs index 23fdd272ffd..2f0be3f3e4e 100644 --- a/compiler/rustc_arena/src/lib.rs +++ b/compiler/rustc_arena/src/lib.rs @@ -407,6 +407,8 @@ impl Default for DroplessArena { #[inline] fn default() -> DroplessArena { DroplessArena { + // We set both `start` and `end` to 0 so that the first call to + // alloc() will trigger a grow(). start: Cell::new(ptr::null_mut()), end: Cell::new(ptr::null_mut()), chunks: Default::default(), @@ -417,7 +419,7 @@ fn default() -> DroplessArena { impl DroplessArena { fn grow(&self, layout: Layout) { // Add some padding so we can align `self.end` while - // stilling fitting in a `layout` allocation. + // still fitting in a `layout` allocation. let additional = layout.size() + cmp::max(DROPLESS_ALIGNMENT, layout.align()) - 1; unsafe { @@ -441,7 +443,7 @@ fn grow(&self, layout: Layout) { let mut chunk = ArenaChunk::new(align_up(new_cap, PAGE)); self.start.set(chunk.start()); - // Align the end to DROPLESS_ALIGNMENT + // Align the end to DROPLESS_ALIGNMENT. let end = align_down(chunk.end().addr(), DROPLESS_ALIGNMENT); // Make sure we don't go past `start`. This should not happen since the allocation