Struct PortFuncstackFrame 

pub struct PortFuncstackFrame;

!!! WARNING: Rust-only helper, no C counterpart !!!

This is NOT a port of anything. No C function corresponds to it; it exists only because a Rust port can reach a sibling port’s body without the frame a shell-function call would have opened.

It supplies ONLY the FUNCSTACK half of a doshfunc frame — the push at c:Src/exec.c:6005-6016 and the pop at c:6218-6219 — and nothing else of that prologue.

It is deliberately NOT doshfunc itself. doshfunc also bumps locallevel, and comptags is indexed by that level (Src/Zle/computil.c:3782). The ports that call _impl bodies pair their own inc_locallevel/dec_locallevel around a _tags registration and the comptags -A lookup that consumes it; a second bump landing between them splits that pair. _message.rs records that dispatching there also flips fourteen tests (dash_e_registers_its_own_tag_level, default_mode_registers_the_messages_tag, and eleven _x_* routes_to_message_*), which is why the level is managed by hand and only the frame is restored here.

Why the frame has to exist at all: _next_label sh:9 (and _all_labels sh:27) gate their _comp_tags strip on (( $#funcstack > _tags_level )). A raw _next_label_impl call leaves $#funcstack one short, so that guard is unobservable and a tag zsh drops survives.

The FUNCSTACK half of a doshfunc frame, for a port that deliberately calls a sibling port’s raw _impl body instead of dispatching.

doshfunc pushes one FS_FUNC frame per shell-function call (Src/exec.c:6005-6016) and pops it on the way out (c:6218-6219). call_compfn gets that for free; a raw _impl call does not, and call_compfn’s own contract says the caller “must supply the missing piece inside its own fallback closure rather than assume this helper does it”.

The missing frame is not cosmetic. _next_label sh:9 and _all_labels sh:27 gate their _comp_tags strip on (( $#funcstack > _tags_level )), so a callee running one frame shallower than zsh’s silently keeps a tag zsh drops. Measured on _arguments : '1::optional delimiter:(\:)' '*:spec' (an empty rest action, which sh:413-417 routes to _message -e):

zsh    _tags_level=9   _comp_tags=' argument-rest '
zshrs  _tags_level=8   _comp_tags=' argument-1  argument-rest '

This guard supplies ONLY the funcstack frame. It deliberately does not go through doshfunc, which would also bump locallevel — comptags is indexed by that level (Src/Zle/computil.c:3782), and the ports that call _impl bodies pair their own inc_locallevel/dec_locallevel around the registration and its lookup. Adding a second bump between them would split that pair.

Implementations

impl PortFuncstackFrame

pub fn push(name: &str) -> Self

funcstack = &funcsave->fstack with tp = FS_FUNC (c:6005-6016).

Trait Implementations

impl Drop for PortFuncstackFrame

fn drop(&mut self)

c:6218-6219 — if (fpushed) funcstack = funcstack->prev;

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.