Auto merge of #142997 - workingjubilee:rollup-6lxec87, r=workingjubilee

Rollup of 15 pull requests

Successful merges:

 - rust-lang/rust#135731 (Implement parsing of pinned borrows)
 - rust-lang/rust#138780 (Add `#[loop_match]` for improved DFA codegen)
 - rust-lang/rust#142453 (Windows: make `read_dir` stop iterating after the first error is encountered)
 - rust-lang/rust#142633 (Error on invalid signatures for interrupt ABIs)
 - rust-lang/rust#142768 (Avoid a bitcast FFI call in transmuting)
 - rust-lang/rust#142825 (Port `#[track_caller]` to the new attribute system)
 - rust-lang/rust#142844 (Enable short-ice for Windows)
 - rust-lang/rust#142934 (Tweak `-Zmacro-stats` measurement.)
 - rust-lang/rust#142955 (Couple of test suite fixes for cg_clif)
 - rust-lang/rust#142977 (rustdoc: Don't mark `#[target_feature]` functions as ⚠)
 - rust-lang/rust#142980 (Reduce mismatched-lifetime-syntaxes suggestions to MaybeIncorrect)
 - rust-lang/rust#142982 (Corrected spelling mistake in c_str.rs)
 - rust-lang/rust#142983 (Taint body on invalid call ABI)
 - rust-lang/rust#142988 (Update wasm-component-ld to 0.5.14)
 - rust-lang/rust#142993 (Update cargo)

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 55 insertions, 3 deletions

diff --git a/src/doc/unstable-book/src/compiler-flags/macro-stats.md b/src/doc/unstable-book/src/compiler-flags/macro-stats.md
index b2622cff057..f3fa69058a7 100644
--- a/src/doc/unstable-book/src/compiler-flags/macro-stats.md
+++ b/src/doc/unstable-book/src/compiler-flags/macro-stats.md
@@ -10,12 +10,12 @@ generated code is normally invisible to the programmer.
 
 This flag helps identify such cases. When enabled, the compiler measures the
 effect on code size of all used macros and prints a table summarizing that
-effect. For each distinct macro, it counts how many times it is used, and the
-net effect on code size (in terms of lines of code, and bytes of code). The
+effect. For each distinct macro, it counts how many times it is used, and how
+much code it produces when expanded (in lines of code, and bytes of code). The
 code size evaluation uses the compiler's internal pretty-printing, and so will
 be independent of the formatting in the original code.
 
-Note that the net effect of a macro may be negative. E.g. the `cfg!` and
+Note that the output size of a macro may be zero. E.g. the `cfg!` and
 `#[test]` macros often strip out code.
 
 If a macro is identified as causing a large increase in code size, it is worth
diff --git a/src/doc/unstable-book/src/language-features/loop-match.md b/src/doc/unstable-book/src/language-features/loop-match.md
new file mode 100644
index 00000000000..4cc763d3434
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/loop-match.md
@@ -0,0 +1,52 @@
+# `loop_match`
+
+The tracking issue for this feature is: [#132306]
+
+[#132306]: https://github.com/rust-lang/rust/issues/132306
+
+------
+
+The `#[loop_match]` and `#[const_continue]` attributes can be used to improve the code
+generation of logic that fits this shape:
+
+```ignore (pseudo-rust)
+loop {
+    state = 'blk: {
+        match state {
+            State::A => {
+                break 'blk State::B
+            }
+            State::B => { /* ... */ }
+            /* ... */
+        }
+    }
+}
+```
+
+Here the loop itself can be annotated with `#[loop_match]`, and any `break 'blk` with
+`#[const_continue]` if the value is know at compile time:
+
+```ignore (pseudo-rust)
+#[loop_match]
+loop {
+    state = 'blk: {
+        match state {
+            State::A => {
+                #[const_continue]
+                break 'blk State::B
+            }
+            State::B => { /* ... */ }
+            /* ... */
+        }
+    }
+}
+```
+
+The observable behavior of this loop is exactly the same as without the extra attributes.
+The difference is in the generated output: normally, when the state is `A`, control flow
+moves from the `A` branch, back to the top of the loop, then to the `B` branch. With the
+attributes, The `A` branch will immediately jump to the `B` branch.
+
+Removing the indirection can be beneficial for stack usage and branch prediction, and
+enables other optimizations by clearly splitting out the control flow paths that your
+program will actually use.