Auto merge of #129063 - the8472:cold-opt-size, r=Amanieu

Apply size optimizations to panic machinery and some cold functions

* std dependencies gimli and addr2line are now built with opt-level=s
* various panic-related methods and `#[cold]` methods are now marked `#[optimize(size)]`

Panics should be cold enough that it doesn't make sense to optimize them for speed. The only tradeoff here is if someone does a lot of backtrace captures (without panics) and printing then the opt-level change might impact their perf.

Seems to be the first use of the optimize attribute. Tracking issue #54882

4 files changed, 7 insertions, 0 deletions

diff --git a/library/alloc/src/alloc.rs b/library/alloc/src/alloc.rs
index db2d752cfde..cddf4f6f399 100644
--- a/library/alloc/src/alloc.rs
+++ b/library/alloc/src/alloc.rs
@@ -372,6 +372,7 @@ extern "Rust" {
 #[rustc_const_unstable(feature = "const_alloc_error", issue = "92523")]
 #[cfg(all(not(no_global_oom_handling), not(test)))]
 #[cold]
+#[optimize(size)]
 pub const fn handle_alloc_error(layout: Layout) -> ! {
     const fn ct_error(_: Layout) -> ! {
         panic!("allocation failed");
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index c459a8da820..7aaa4e73df7 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -183,6 +183,7 @@
 #![feature(multiple_supertrait_upcastable)]
 #![feature(negative_impls)]
 #![feature(never_type)]
+#![feature(optimize_attribute)]
 #![feature(rustc_allow_const_fn_unstable)]
 #![feature(rustc_attrs)]
 #![feature(slice_internals)]
diff --git a/library/alloc/src/raw_vec.rs b/library/alloc/src/raw_vec.rs
index 9c8fa7ceff4..a651ba067e4 100644
--- a/library/alloc/src/raw_vec.rs
+++ b/library/alloc/src/raw_vec.rs
@@ -782,6 +782,7 @@ where
 // Central function for reserve error handling.
 #[cfg(not(no_global_oom_handling))]
 #[cold]
+#[optimize(size)]
 fn handle_error(e: TryReserveError) -> ! {
     match e.kind() {
         CapacityOverflow => capacity_overflow(),
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index cfd2e4a1512..162791ba59d 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -1519,6 +1519,7 @@ impl<T, A: Allocator> Vec<T, A> {
         #[cold]
         #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
         #[track_caller]
+        #[optimize(size)]
         fn assert_failed(index: usize, len: usize) -> ! {
             panic!("swap_remove index (is {index}) should be < len (is {len})");
         }
@@ -1567,6 +1568,7 @@ impl<T, A: Allocator> Vec<T, A> {
         #[cold]
         #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
         #[track_caller]
+        #[optimize(size)]
         fn assert_failed(index: usize, len: usize) -> ! {
             panic!("insertion index (is {index}) should be <= len (is {len})");
         }
@@ -1629,6 +1631,7 @@ impl<T, A: Allocator> Vec<T, A> {
         #[cold]
         #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
         #[track_caller]
+        #[optimize(size)]
         fn assert_failed(index: usize, len: usize) -> ! {
             panic!("removal index (is {index}) should be < len (is {len})");
         }
@@ -2317,6 +2320,7 @@ impl<T, A: Allocator> Vec<T, A> {
         #[cold]
         #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
         #[track_caller]
+        #[optimize(size)]
         fn assert_failed(at: usize, len: usize) -> ! {
             panic!("`at` split index (is {at}) should be <= len (is {len})");
         }