more ABIs are now allowed in variadic functions

src/changelog.rst

@@ -31,6 +31,34 @@ Language changes in Rust 1.91.0
 - `Stabilize declaration of C-style variadic functions for 'sysv64', 'win64', 'efiapi', and 'aapcs' ABIs <https://github.com/rust-lang/rust/pull/144066>`_.
   This brings these ABIs in line with the C ABI: variadic functions can be declared in extern blocks but not defined.
 
+  - Changed paragraphs:
+
+    - :p:`fls_hbn1l42xmr3h`
+    - :p:`fls_dbbfqaqa80r8`
+    - :p:`fls_icdzs1mjh0n4`
+
+  - New paragraphs:
+
+    - :p:`fls_OR85NVifPwjr`
+    - :p:`fls_4s2IdfYDzPrX`
+    - :p:`fls_ZJJppPfiJRou`
+    - :p:`fls_jOyZh9ujWWHQ`
+    - :p:`fls_Xdr0bFwxhWiB`
+    - :p:`fls_DpTFEHZAABdD`
+    - :p:`fls_6urL6fZ5cpaA`
+    - :p:`fls_TMOzb6cYIOlH`
+    - :p:`fls_eHPWHrvs7ETl`
+    - :p:`fls_mjCrvmikm58M`
+    - :p:`fls_4EUb9zFatZ97`
+    - :p:`fls_4B4B5FIqAes9`
+    - :p:`fls_b7FTlWfnX2OI`
+    - :p:`fls_o4uSLPo00KUg`
+    - :p:`fls_UippZpUyYpHl`
+    - :p:`fls_CIyK8BYzzo26`
+    - :p:`fls_ccFdnlX5HIYk`
+    - :p:`fls_xrCRprWS13R1`
+    - :p:`fls_JHlqXjn4Sf07`
+
 - `Add dangling_pointers_from_locals lint to warn against dangling pointers from local variables <https://github.com/rust-lang/rust/pull/144322>`_
 
   - No change: lints are not part of the FLS

src/ffi.rst

@@ -74,8 +74,7 @@ The following :t:`[ABI]s` are supported:
   :dt:`Rust ABI`.
 
 * :dp:`fls_8m7pc3riokst`
-  ``extern "system"`` - The operating system-dependent :t:`ABI`, referred to as
-  :dt:`external system ABI`.
+  ``extern "system"`` - The operating system-dependent :t:`ABI`.
 
 * :dp:`fls_NQAzj5ai1La5`
   ``extern "system-unwind"`` - The same as ``extern "system"`` with the
@@ -96,11 +95,19 @@ A tool is allowed to specify additional :t:`[ABI]s`. These :t:`[ABI]s` may
 include, but may not be limited to, the following:
 
 * :dp:`fls_dbbfqaqa80r8`
-  ``extern "aapcs"`` - The ARM :t:`ABI`.
+  ``extern "aapcs"`` - The soft-float ABI for 32-bit ARM targets.
+
+* :dp:`fls_UippZpUyYpHl`
+  ``extern "aapcs-unwind"`` - The same as ``extern "aapcs"``
+  with the addition that unwinding across FFI is permitted.
 
 * :dp:`fls_36qrs2fxxvi7`
   ``extern "cdecl"`` - The x86_32 :t:`ABI` of :t:`C` code.
 
+* :dp:`fls_CIyK8BYzzo26`
+  ``extern "cdecl-unwind"`` - The same as ``extern "cdecl"``
+  with the addition that unwinding across FFI is permitted.
+
 * :dp:`fls_6rtj6rwqxojh`
   ``extern "fastcall"`` - The ``fastcall`` :t:`ABI` that corresponds to MSVC's
   ``__fastcall`` and GCC and clang's ``__attribute__((fastcall))``.
@@ -111,13 +118,24 @@ include, but may not be limited to, the following:
 * :dp:`fls_7t7yxh94wnbl`
   ``extern "sysv64"`` - The x86_64 non-Windows :t:`ABI` of :t:`C` code.
 
+* :dp:`fls_ccFdnlX5HIYk`
+  ``extern "sysv64-unwind"`` - The same as ``extern "sysv64"``
+  with the addition that unwinding across FFI is permitted.
+
 * :dp:`fls_sxj4vy39sj4g`
   ``extern "vectorcall"`` - The ``vectorcall`` :t:`ABI` that corresponds to
   MSVC's ``__vectorcall`` and clang's ``__attribute__((vectorcall))``.
 
 * :dp:`fls_tyjs1x4j8ovp`
   ``extern "win64"`` - The x86_64 Windows :t:`ABI` of :t:`C` code.
 
+* :dp:`fls_xrCRprWS13R1`
+  ``extern "win64-unwind"`` - The same as ``extern "win64"``
+  with the addition that unwinding across FFI is permitted.
+
+* :dp:`fls_JHlqXjn4Sf07`
+  ``extern "efiapi"`` - The :t:`ABI` for `UEFI <https://uefi.org/specifications>`_.
+
 .. rubric:: Undefined Behavior
 
 :dp:`fls_M4LqHf8hbPA8`

src/functions.rst

@@ -103,9 +103,39 @@ The :t:`expected type` of the :t:`pattern` of a :t:`function parameter` is the :
 :dp:`fls_PGDKWK7nPvgw`
 The :t:`[binding]s` of all :t:`[pattern]s` of all :t:`[function parameter]s` of a :t:`function` shall not shadow another.
 
+:dp:`fls_o4uSLPo00KUg`
+A :dt:`variadic function` is an :t:`external function` that specifies
+:s:`FunctionParameterVariadicPart` as the last :t:`function parameter`.
+
 :dp:`fls_icdzs1mjh0n4`
-A :t:`function` shall not specify a :s:`FunctionParameterVariadicPart` unless
-it is an :t:`external function`.
+A :t:`variadic function` shall specify one of the following :t:`[ABI]s`:
+
+* :dp:`fls_OR85NVifPwjr`
+  ``extern "C"``
+* :dp:`fls_4s2IdfYDzPrX`
+  ``extern "C-unwind"``
+* :dp:`fls_ZJJppPfiJRou`
+  ``extern "aapcs"``
+* :dp:`fls_jOyZh9ujWWHQ`
+  ``extern "aapcs-unwind"``
+* :dp:`fls_Xdr0bFwxhWiB`
+  ``extern "cdecl"``
+* :dp:`fls_DpTFEHZAABdD`
+  ``extern "cdecl-unwind"``
+* :dp:`fls_b7FTlWfnX2OI`
+  ``extern "efiapi"``
+* :dp:`fls_6urL6fZ5cpaA`
+  ``extern "system"``
+* :dp:`fls_TMOzb6cYIOlH`
+  ``extern "system-unwind"``
+* :dp:`fls_eHPWHrvs7ETl`
+  ``extern "sysv64"``
+* :dp:`fls_mjCrvmikm58M`
+  ``extern "sysv64-unwind"``
+* :dp:`fls_4EUb9zFatZ97`
+  ``extern "win64"``
+* :dp:`fls_4B4B5FIqAes9`
+  ``extern "win64-unwind"``
 
 :dp:`fls_vljy4mm0zca2`
 A :t:`return type` is the :t:`type` of the result a :t:`function`, :t:`closure type` or :t:`function pointer type` returns.

src/types-and-traits.rst

@@ -978,8 +978,7 @@ A :t:`variadic part` indicates the presence of :t:`C`-like optional
 parameters.
 
 :dp:`fls_hbn1l42xmr3h`
-A :t:`variadic part` shall be specified only when the :t:`ABI` of the
-:t:`function pointer type` is either ``extern "C"`` or ``extern "cdecl"``.
+A :t:`variadic part` can only be used in a :t:`variadic function`.
 
 :dp:`fls_g1iYVw7upBnH`
 The :t:`return type` of a :t:`function pointer type` is determined as follows: