PR suggestions

Author: Kyle Strand

src/behavior-considered-undefined.md

@@ -51,6 +51,9 @@ code.
 * Calling a function with the wrong call ABI or unwinding from a function with the wrong unwind ABI.
 * Calling a foreign (e.g. C++) function that unwinds (`throw`s) via a function
   declaration or pointer declared with a non-unwinding ABI such as `"C"`
+* Deallocating a Rust stack frame without executing destructors
+  for local variables owned by the stack frame. This can occur
+  with C functions like `longjmp`.
 * Producing an invalid value, even in private fields and locals. "Producing" a
   value happens any time a value is assigned to or read from a place, passed to
   a function/primitive operation or returned from a function/primitive

src/items/functions.md

@@ -211,10 +211,12 @@ The choice of ABI, together with the [panic mode][panic-modes], determines the
 behavior when unwinding out of a function.
 
 In the table below, "Unforced foreign unwind" refers to something like a C++
-exception; the table indicates the behavior when entering a Rust stackframe via
-an function or function pointer declared with the specified ABI string.
-Additionally, `C` in the ABI strings may be substituted with `stdcall` or any
-other ABI supported by the language implementation.
+exception; the table indicates the behavior of an unwinding
+operation reaching each type of ABI boundary (function
+declaration or definition using the corresponding ABI string).
+Additionally, `C` in the ABI strings may be substituted with
+`stdcall` or any other ABI supported by the language
+implementation.
 
 | panic runtime  | ABI          | `panic`-unwind                        | Unforced foreign unwind |
 | -------------- | ------------ | ------------------------------------- | ----------------------- |

src/linkage.md

@@ -219,12 +219,14 @@ both of the following characteristics:
 * It contains a call to an `-unwind` foreign function or function pointer
 * It was compiled with `panic=unwind`
 
+`rustc` enforces this restriction at link-time. To guarantee that
+a library will be linkable regardless of the panic mode used at
+link-time, the `ffi_unwind_calls` may be used. The lint flags any
+calls to `-unwind` foreign functions or function pointers.
+
 Note: Cargo will automatically unify all crates to use the same `panic`
 runtime, so this prohibition does not apply to projects compiled with Cargo.
 
-<!-- TODO: edit the above to indicate that this prohibition is enforced by
-`rustc` once https://github.com/rust-lang/rust/pull/97235 has been merged -->
-
 [`cfg` attribute `target_feature` option]: conditional-compilation.md#target_feature
 [configuration option]: conditional-compilation.md
 [procedural macros]: procedural-macros.md