add #[hdl] let destructuring and, while at it, tuple patterns
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This commit is contained in:
Jacob Lifshay 2025-02-10 22:49:41 -08:00
parent 209d5b5fe1
commit 86a1bb46be
Signed by: programmerjake
SSH key fingerprint: SHA256:HnFTLGpSm4Q4Fj502oCFisjZSoakwEuTsJJMSke63RQ
6 changed files with 454 additions and 13 deletions

View file

@ -1109,7 +1109,7 @@ fn parse_quote_let_pat<T, R: ToTokens, C: Borrow<Token![:]>>(
}
}
fn wrap_ty_with_expr(ty: impl ToTokens) -> Type {
pub(crate) fn wrap_ty_with_expr(ty: impl ToTokens) -> Type {
parse_quote_spanned! {ty.span()=>
::fayalite::expr::Expr<#ty>
}
@ -1586,7 +1586,7 @@ impl Visitor<'_> {
}
}
fn empty_let() -> Local {
pub(crate) fn empty_let() -> Local {
Local {
attrs: vec![],
let_token: Default::default(),
@ -1672,7 +1672,7 @@ impl Fold for Visitor<'_> {
}
}
fn fold_local(&mut self, let_stmt: Local) -> Local {
fn fold_local(&mut self, mut let_stmt: Local) -> Local {
match self
.errors
.ok(HdlAttr::<Nothing, kw::hdl>::parse_and_leave_attr(
@ -1682,6 +1682,25 @@ impl Fold for Visitor<'_> {
Some(None) => return fold_local(self, let_stmt),
Some(Some(HdlAttr { .. })) => {}
};
let mut pat = &let_stmt.pat;
if let Pat::Type(pat_type) = pat {
pat = &pat_type.pat;
}
let Pat::Ident(syn::PatIdent {
attrs: _,
by_ref: None,
mutability: _,
ident: _,
subpat: None,
}) = pat
else {
let hdl_attr = HdlAttr::<Nothing, kw::hdl>::parse_and_take_attr(&mut let_stmt.attrs)
.ok()
.flatten()
.expect("already checked above");
let let_stmt = fold_local(self, let_stmt);
return self.process_hdl_let_pat(hdl_attr, let_stmt);
};
let hdl_let = syn::parse2::<HdlLet<HdlLetKind<Type>>>(let_stmt.into_token_stream());
let Some(hdl_let) = self.errors.ok(hdl_let) else {
return empty_let();

View file

@ -3,22 +3,111 @@
use crate::{
fold::{impl_fold, DoFold},
kw,
module::transform_body::{with_debug_clone_and_fold, Visitor},
module::transform_body::{empty_let, with_debug_clone_and_fold, wrap_ty_with_expr, Visitor},
Errors, HdlAttr, PairsIterExt,
};
use proc_macro2::{Span, TokenStream};
use quote::{format_ident, quote_spanned, ToTokens, TokenStreamExt};
use std::collections::BTreeSet;
use syn::{
fold::{fold_arm, fold_expr_match, fold_pat, Fold},
fold::{fold_arm, fold_expr_match, fold_local, fold_pat, Fold},
parse::Nothing,
parse_quote_spanned,
punctuated::Punctuated,
spanned::Spanned,
token::{Brace, Paren},
Arm, Attribute, Expr, ExprMatch, FieldPat, Ident, Member, Pat, PatIdent, PatOr, PatParen,
PatPath, PatRest, PatStruct, PatTupleStruct, PatWild, Path, PathSegment, Token, TypePath,
Arm, Attribute, Expr, ExprMatch, FieldPat, Ident, Local, Member, Pat, PatIdent, PatOr,
PatParen, PatPath, PatRest, PatStruct, PatTuple, PatTupleStruct, PatWild, Path, PathSegment,
Token, TypePath,
};
macro_rules! visit_trait {
(
$($vis:vis fn $fn:ident($state:ident: _, $value:ident: &$Value:ty) $block:block)*
) => {
trait VisitMatchPat<'a> {
$(fn $fn(&mut self, $value: &'a $Value) {
$fn(self, $value);
})*
}
$($vis fn $fn<'a>($state: &mut (impl ?Sized + VisitMatchPat<'a>), $value: &'a $Value) $block)*
};
}
visit_trait! {
fn visit_match_pat_binding(_state: _, v: &MatchPatBinding) {
let MatchPatBinding { ident: _ } = v;
}
fn visit_match_pat_wild(_state: _, v: &MatchPatWild) {
let MatchPatWild { underscore_token: _ } = v;
}
fn visit_match_pat_rest(_state: _, v: &MatchPatRest) {
let MatchPatRest { dot2_token: _ } = v;
}
fn visit_match_pat_paren(state: _, v: &MatchPatParen<MatchPat>) {
let MatchPatParen { paren_token: _, pat } = v;
state.visit_match_pat(pat);
}
fn visit_match_pat_paren_simple(state: _, v: &MatchPatParen<MatchPatSimple>) {
let MatchPatParen { paren_token: _, pat } = v;
state.visit_match_pat_simple(pat);
}
fn visit_match_pat_or(state: _, v: &MatchPatOr<MatchPat>) {
let MatchPatOr { leading_vert: _, cases } = v;
for v in cases {
state.visit_match_pat(v);
}
}
fn visit_match_pat_or_simple(state: _, v: &MatchPatOr<MatchPatSimple>) {
let MatchPatOr { leading_vert: _, cases } = v;
for v in cases {
state.visit_match_pat_simple(v);
}
}
fn visit_match_pat_struct_field(state: _, v: &MatchPatStructField) {
let MatchPatStructField { field_name: _, colon_token: _, pat } = v;
state.visit_match_pat_simple(pat);
}
fn visit_match_pat_struct(state: _, v: &MatchPatStruct) {
let MatchPatStruct { match_span: _, path: _, brace_token: _, fields, rest: _ } = v;
for v in fields {
state.visit_match_pat_struct_field(v);
}
}
fn visit_match_pat_tuple(state: _, v: &MatchPatTuple) {
let MatchPatTuple { paren_token: _, fields } = v;
for v in fields {
state.visit_match_pat_simple(v);
}
}
fn visit_match_pat_enum_variant(state: _, v: &MatchPatEnumVariant) {
let MatchPatEnumVariant {match_span:_, variant_path: _, enum_path: _, variant_name: _, field } = v;
if let Some((_, v)) = field {
state.visit_match_pat_simple(v);
}
}
fn visit_match_pat_simple(state: _, v: &MatchPatSimple) {
match v {
MatchPatSimple::Paren(v) => state.visit_match_pat_paren_simple(v),
MatchPatSimple::Or(v) => state.visit_match_pat_or_simple(v),
MatchPatSimple::Binding(v) => state.visit_match_pat_binding(v),
MatchPatSimple::Wild(v) => state.visit_match_pat_wild(v),
MatchPatSimple::Rest(v) => state.visit_match_pat_rest(v),
}
}
fn visit_match_pat(state: _, v: &MatchPat) {
match v {
MatchPat::Simple(v) => state.visit_match_pat_simple(v),
MatchPat::Or(v) => state.visit_match_pat_or(v),
MatchPat::Paren(v) => state.visit_match_pat_paren(v),
MatchPat::Struct(v) => state.visit_match_pat_struct(v),
MatchPat::Tuple(v) => state.visit_match_pat_tuple(v),
MatchPat::EnumVariant(v) => state.visit_match_pat_enum_variant(v),
}
}
}
with_debug_clone_and_fold! {
struct MatchPatBinding<> {
ident: Ident,
@ -53,6 +142,15 @@ with_debug_clone_and_fold! {
}
}
impl<P> MatchPatOr<P> {
/// returns the first `|` between two patterns
fn first_inner_vert(&self) -> Option<Token![|]> {
let mut pairs = self.cases.pairs();
pairs.next_back();
pairs.next().and_then(|v| v.into_tuple().1.copied())
}
}
impl<P: ToTokens> ToTokens for MatchPatOr<P> {
fn to_tokens(&self, tokens: &mut TokenStream) {
let Self {
@ -77,6 +175,19 @@ impl ToTokens for MatchPatWild {
}
}
with_debug_clone_and_fold! {
struct MatchPatRest<> {
dot2_token: Token![..],
}
}
impl ToTokens for MatchPatRest {
fn to_tokens(&self, tokens: &mut TokenStream) {
let Self { dot2_token } = self;
dot2_token.to_tokens(tokens);
}
}
with_debug_clone_and_fold! {
struct MatchPatStructField<> {
field_name: Ident,
@ -159,6 +270,25 @@ impl ToTokens for MatchPatStruct {
}
}
with_debug_clone_and_fold! {
struct MatchPatTuple<> {
paren_token: Paren,
fields: Punctuated<MatchPatSimple, Token![,]>,
}
}
impl ToTokens for MatchPatTuple {
fn to_tokens(&self, tokens: &mut TokenStream) {
let Self {
paren_token,
fields,
} = self;
paren_token.surround(tokens, |tokens| {
fields.to_tokens(tokens);
})
}
}
with_debug_clone_and_fold! {
struct MatchPatEnumVariant<> {
match_span: Span,
@ -194,6 +324,7 @@ enum MatchPatSimple {
Or(MatchPatOr<MatchPatSimple>),
Binding(MatchPatBinding),
Wild(MatchPatWild),
Rest(MatchPatRest),
}
impl_fold! {
@ -202,6 +333,7 @@ impl_fold! {
Or(MatchPatOr<MatchPatSimple>),
Binding(MatchPatBinding),
Wild(MatchPatWild),
Rest(MatchPatRest),
}
}
@ -212,6 +344,7 @@ impl ToTokens for MatchPatSimple {
Self::Paren(v) => v.to_tokens(tokens),
Self::Binding(v) => v.to_tokens(tokens),
Self::Wild(v) => v.to_tokens(tokens),
Self::Rest(v) => v.to_tokens(tokens),
}
}
}
@ -278,6 +411,7 @@ trait ParseMatchPat: Sized {
fn or(v: MatchPatOr<Self>) -> Self;
fn paren(v: MatchPatParen<Self>) -> Self;
fn struct_(state: &mut HdlMatchParseState<'_>, v: MatchPatStruct) -> Result<Self, ()>;
fn tuple(state: &mut HdlMatchParseState<'_>, v: MatchPatTuple) -> Result<Self, ()>;
fn enum_variant(state: &mut HdlMatchParseState<'_>, v: MatchPatEnumVariant)
-> Result<Self, ()>;
fn parse(state: &mut HdlMatchParseState<'_>, pat: Pat) -> Result<Self, ()> {
@ -462,7 +596,34 @@ trait ParseMatchPat: Sized {
}) => Ok(Self::simple(MatchPatSimple::Wild(MatchPatWild {
underscore_token,
}))),
Pat::Tuple(_) | Pat::Slice(_) | Pat::Const(_) | Pat::Lit(_) | Pat::Range(_) => {
Pat::Tuple(PatTuple {
attrs: _,
paren_token,
elems,
}) => {
let fields = elems
.into_pairs()
.filter_map_pair_value(|field_pat| {
if let Pat::Rest(PatRest {
attrs: _,
dot2_token,
}) = field_pat
{
Some(MatchPatSimple::Rest(MatchPatRest { dot2_token }))
} else {
MatchPatSimple::parse(state, field_pat).ok()
}
})
.collect();
Self::tuple(
state,
MatchPatTuple {
paren_token,
fields,
},
)
}
Pat::Slice(_) | Pat::Const(_) | Pat::Lit(_) | Pat::Range(_) => {
state
.errors
.error(pat, "not yet implemented in #[hdl] patterns");
@ -497,6 +658,14 @@ impl ParseMatchPat for MatchPatSimple {
Err(())
}
fn tuple(state: &mut HdlMatchParseState<'_>, v: MatchPatTuple) -> Result<Self, ()> {
state.errors.push(syn::Error::new(
v.paren_token.span.open(),
"matching tuples is not yet implemented inside structs/enums in #[hdl] patterns",
));
Err(())
}
fn enum_variant(
state: &mut HdlMatchParseState<'_>,
v: MatchPatEnumVariant,
@ -515,6 +684,7 @@ enum MatchPat {
Or(MatchPatOr<MatchPat>),
Paren(MatchPatParen<MatchPat>),
Struct(MatchPatStruct),
Tuple(MatchPatTuple),
EnumVariant(MatchPatEnumVariant),
}
@ -524,6 +694,7 @@ impl_fold! {
Or(MatchPatOr<MatchPat>),
Paren(MatchPatParen<MatchPat>),
Struct(MatchPatStruct),
Tuple(MatchPatTuple),
EnumVariant(MatchPatEnumVariant),
}
}
@ -545,6 +716,10 @@ impl ParseMatchPat for MatchPat {
Ok(Self::Struct(v))
}
fn tuple(_state: &mut HdlMatchParseState<'_>, v: MatchPatTuple) -> Result<Self, ()> {
Ok(Self::Tuple(v))
}
fn enum_variant(
_state: &mut HdlMatchParseState<'_>,
v: MatchPatEnumVariant,
@ -560,6 +735,7 @@ impl ToTokens for MatchPat {
Self::Or(v) => v.to_tokens(tokens),
Self::Paren(v) => v.to_tokens(tokens),
Self::Struct(v) => v.to_tokens(tokens),
Self::Tuple(v) => v.to_tokens(tokens),
Self::EnumVariant(v) => v.to_tokens(tokens),
}
}
@ -622,10 +798,6 @@ struct RewriteAsCheckMatch {
}
impl Fold for RewriteAsCheckMatch {
fn fold_field_pat(&mut self, mut i: FieldPat) -> FieldPat {
i.colon_token = Some(Token![:](i.member.span()));
i
}
fn fold_pat(&mut self, pat: Pat) -> Pat {
match pat {
Pat::Ident(mut pat_ident) => match parse_enum_ident(pat_ident.ident) {
@ -740,6 +912,30 @@ impl Fold for RewriteAsCheckMatch {
// don't recurse into expressions
i
}
fn fold_local(&mut self, mut let_stmt: Local) -> Local {
if let Some(syn::LocalInit {
eq_token,
expr: _,
diverge,
}) = let_stmt.init.take()
{
let_stmt.init = Some(syn::LocalInit {
eq_token,
expr: parse_quote_spanned! {self.span=>
__match_value
},
diverge: diverge.map(|(else_, _expr)| {
(
else_,
parse_quote_spanned! {self.span=>
match __infallible {}
},
)
}),
});
}
fold_local(self, let_stmt)
}
}
struct HdlMatchParseState<'a> {
@ -747,7 +943,123 @@ struct HdlMatchParseState<'a> {
errors: &'a mut Errors,
}
struct HdlLetPatVisitState<'a> {
errors: &'a mut Errors,
bindings: BTreeSet<&'a Ident>,
}
impl<'a> VisitMatchPat<'a> for HdlLetPatVisitState<'a> {
fn visit_match_pat_binding(&mut self, v: &'a MatchPatBinding) {
self.bindings.insert(&v.ident);
}
fn visit_match_pat_or(&mut self, v: &'a MatchPatOr<MatchPat>) {
if let Some(first_inner_vert) = v.first_inner_vert() {
self.errors.error(
first_inner_vert,
"or-patterns are not supported in let statements",
);
}
visit_match_pat_or(self, v);
}
fn visit_match_pat_or_simple(&mut self, v: &'a MatchPatOr<MatchPatSimple>) {
if let Some(first_inner_vert) = v.first_inner_vert() {
self.errors.error(
first_inner_vert,
"or-patterns are not supported in let statements",
);
}
visit_match_pat_or_simple(self, v);
}
fn visit_match_pat_enum_variant(&mut self, v: &'a MatchPatEnumVariant) {
self.errors.error(v, "refutable pattern in let statement");
}
}
impl Visitor<'_> {
pub(crate) fn process_hdl_let_pat(
&mut self,
_hdl_attr: HdlAttr<Nothing, kw::hdl>,
mut let_stmt: Local,
) -> Local {
let span = let_stmt.let_token.span();
if let Pat::Type(pat) = &mut let_stmt.pat {
*pat.ty = wrap_ty_with_expr((*pat.ty).clone());
}
let check_let_stmt = RewriteAsCheckMatch { span }.fold_local(let_stmt.clone());
let Local {
attrs: _,
let_token,
pat,
init,
semi_token,
} = let_stmt;
self.require_normal_module_or_fn(let_token);
let Some(syn::LocalInit {
eq_token,
expr,
diverge,
}) = init
else {
self.errors
.error(let_token, "#[hdl] let must be assigned a value");
return empty_let();
};
if let Some((else_, _)) = diverge {
// TODO: implement let-else
self.errors
.error(else_, "#[hdl] let ... else { ... } is not implemented");
return empty_let();
}
let Ok(pat) = MatchPat::parse(
&mut HdlMatchParseState {
match_span: span,
errors: &mut self.errors,
},
pat,
) else {
return empty_let();
};
let mut state = HdlLetPatVisitState {
errors: &mut self.errors,
bindings: BTreeSet::new(),
};
state.visit_match_pat(&pat);
let HdlLetPatVisitState {
errors: _,
bindings,
} = state;
let retval = parse_quote_spanned! {span=>
let (#(#bindings,)* __scope,) = {
type __MatchTy<T> = <T as ::fayalite::ty::Type>::MatchVariant;
let __match_expr = ::fayalite::expr::ToExpr::to_expr(&(#expr));
::fayalite::expr::check_match_expr(__match_expr, |__match_value, __infallible| {
#[allow(unused_variables)]
#check_let_stmt
match __infallible {}
});
let mut __match_iter = ::fayalite::module::match_(__match_expr);
let ::fayalite::__std::option::Option::Some(__match_variant) = ::fayalite::__std::iter::Iterator::next(&mut __match_iter) else {
::fayalite::__std::unreachable!("#[hdl] let with uninhabited type");
};
let ::fayalite::__std::option::Option::None = ::fayalite::__std::iter::Iterator::next(&mut __match_iter) else {
::fayalite::__std::unreachable!("#[hdl] let with refutable pattern");
};
let (__match_variant, __scope) =
::fayalite::ty::MatchVariantAndInactiveScope::match_activate_scope(
__match_variant,
);
#let_token #pat #eq_token __match_variant #semi_token
(#(#bindings,)* __scope,)
};
};
match retval {
syn::Stmt::Local(retval) => retval,
_ => unreachable!(),
}
}
pub(crate) fn process_hdl_match(
&mut self,
_hdl_attr: HdlAttr<Nothing, kw::hdl>,

View file

@ -2,6 +2,7 @@
// See Notices.txt for copyright information
//! ## `#[hdl] let` statements
pub mod destructuring;
pub mod inputs_outputs;
pub mod instances;
pub mod memories;

View file

@ -0,0 +1,33 @@
// SPDX-License-Identifier: LGPL-3.0-or-later
// See Notices.txt for copyright information
//! ### Destructuring Let
//!
//! You can use `#[hdl] let` to destructure types, similarly to Rust `let` statements with non-trivial patterns.
//!
//! `#[hdl] let` statements can only match one level of struct/tuple pattern for now,
//! e.g. you can match with the pattern `MyStruct { a, b }`, but not `MyStruct { a, b: Struct2 { v } }`.
//!
//! ```
//! # use fayalite::prelude::*;
//! #[hdl]
//! struct MyStruct {
//! a: UInt<8>,
//! b: Bool,
//! }
//!
//! #[hdl_module]
//! fn my_module() {
//! #[hdl]
//! let my_input: MyStruct = m.input();
//! #[hdl]
//! let my_output: UInt<8> = m.input();
//! #[hdl]
//! let MyStruct { a, b } = my_input;
//! #[hdl]
//! if b {
//! connect(my_output, a);
//! } else {
//! connect(my_output, 0_hdl_u8);
//! }
//! }
//! ```

View file

@ -7,5 +7,5 @@
//!
//! `#[hdl] match` statements' bodies must evaluate to type `()` for now.
//!
//! `#[hdl] match` statements can only match one level of struct/enum pattern for now,
//! `#[hdl] match` statements can only match one level of struct/tuple/enum pattern for now,
//! e.g. you can match with the pattern `HdlSome(v)`, but not `HdlSome(HdlSome(_))`.

View file

@ -4345,3 +4345,79 @@ circuit check_cfgs:
",
};
}
#[hdl_module(outline_generated)]
pub fn check_let_patterns() {
#[hdl]
let tuple_in: (UInt<1>, SInt<1>, Bool) = m.input();
#[hdl]
let (tuple_0, tuple_1, tuple_2) = tuple_in;
#[hdl]
let tuple_0_out: UInt<1> = m.output();
connect(tuple_0_out, tuple_0);
#[hdl]
let tuple_1_out: SInt<1> = m.output();
connect(tuple_1_out, tuple_1);
#[hdl]
let tuple_2_out: Bool = m.output();
connect(tuple_2_out, tuple_2);
#[hdl]
let test_struct_in: TestStruct<SInt<8>> = m.input();
#[hdl]
let TestStruct::<_> { a, b } = test_struct_in;
#[hdl]
let test_struct_a_out: SInt<8> = m.output();
connect(test_struct_a_out, a);
#[hdl]
let test_struct_b_out: UInt<8> = m.output();
connect(test_struct_b_out, b);
#[hdl]
let test_struct_2_in: TestStruct2 = m.input();
#[hdl]
let TestStruct2 { v } = test_struct_2_in;
#[hdl]
let test_struct_2_v_out: UInt<8> = m.output();
connect(test_struct_2_v_out, v);
#[hdl]
let test_struct_3_in: TestStruct3 = m.input();
#[hdl]
let TestStruct3 {} = test_struct_3_in;
}
#[test]
fn test_let_patterns() {
let _n = SourceLocation::normalize_files_for_tests();
let m = check_let_patterns();
dbg!(m);
#[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
assert_export_firrtl! {
m =>
"/test/check_let_patterns.fir": r"FIRRTL version 3.2.0
circuit check_let_patterns:
type Ty0 = {`0`: UInt<1>, `1`: SInt<1>, `2`: UInt<1>}
type Ty1 = {a: SInt<8>, b: UInt<8>}
type Ty2 = {v: UInt<8>}
type Ty3 = {}
module check_let_patterns: @[module-XXXXXXXXXX.rs 1:1]
input tuple_in: Ty0 @[module-XXXXXXXXXX.rs 2:1]
output tuple_0_out: UInt<1> @[module-XXXXXXXXXX.rs 4:1]
output tuple_1_out: SInt<1> @[module-XXXXXXXXXX.rs 6:1]
output tuple_2_out: UInt<1> @[module-XXXXXXXXXX.rs 8:1]
input test_struct_in: Ty1 @[module-XXXXXXXXXX.rs 10:1]
output test_struct_a_out: SInt<8> @[module-XXXXXXXXXX.rs 12:1]
output test_struct_b_out: UInt<8> @[module-XXXXXXXXXX.rs 14:1]
input test_struct_2_in: Ty2 @[module-XXXXXXXXXX.rs 16:1]
output test_struct_2_v_out: UInt<8> @[module-XXXXXXXXXX.rs 18:1]
input test_struct_3_in: Ty3 @[module-XXXXXXXXXX.rs 20:1]
connect tuple_0_out, tuple_in.`0` @[module-XXXXXXXXXX.rs 5:1]
connect tuple_1_out, tuple_in.`1` @[module-XXXXXXXXXX.rs 7:1]
connect tuple_2_out, tuple_in.`2` @[module-XXXXXXXXXX.rs 9:1]
connect test_struct_a_out, test_struct_in.a @[module-XXXXXXXXXX.rs 13:1]
connect test_struct_b_out, test_struct_in.b @[module-XXXXXXXXXX.rs 15:1]
connect test_struct_2_v_out, test_struct_2_in.v @[module-XXXXXXXXXX.rs 19:1]
",
};
}