From bafdbcadd5e70e4a1a35647002c30efd315621b4 Mon Sep 17 00:00:00 2001
From: Predrag Gruevski <obi1kenobi82@gmail.com>
Date: Tue, 4 Mar 2025 22:02:06 +0000
Subject: [PATCH] rustdoc: Use own logic to print `#[repr(..)]` attributes in
JSON output.
---
src/librustdoc/clean/types.rs | 25 +++++++++++-----
src/rustdoc-json-types/lib.rs | 22 +++++++++++---
tests/rustdoc-json/attrs/repr_align.rs | 2 +-
tests/rustdoc-json/attrs/repr_c.rs | 6 ++--
tests/rustdoc-json/attrs/repr_combination.rs | 23 ++++++++-------
tests/rustdoc-json/attrs/repr_int_enum.rs | 6 ++--
tests/rustdoc-json/attrs/repr_packed.rs | 8 ++---
tests/rustdoc-json/attrs/repr_transparent.rs | 29 ++++++++++++++-----
.../rustdoc-json/enums/discriminant/struct.rs | 2 +-
.../rustdoc-json/enums/discriminant/tuple.rs | 2 +-
10 files changed, 82 insertions(+), 43 deletions(-)
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 3b2dcb3db81..1207f2f0360 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -768,12 +768,22 @@ impl Item {
.iter()
.filter_map(|attr| {
if is_json {
- if matches!(attr, hir::Attribute::Parsed(AttributeKind::Deprecation { .. })) {
- // rustdoc-json stores this in `Item::deprecation`, so we
- // don't want it it `Item::attrs`.
- None
- } else {
- Some(rustc_hir_pretty::attribute_to_string(&tcx, attr))
+ match attr {
+ hir::Attribute::Parsed(AttributeKind::Deprecation { .. }) => {
+ // rustdoc-json stores this in `Item::deprecation`, so we
+ // don't want it it `Item::attrs`.
+ None
+ }
+ rustc_hir::Attribute::Parsed(rustc_attr_parsing::AttributeKind::Repr(
+ ..,
+ )) => {
+ // We have separate pretty-printing logic for `#[repr(..)]` attributes.
+ // For example, there are circumstances where `#[repr(transparent)]`
+ // is applied but should not be publicly shown in rustdoc
+ // because it isn't public API.
+ None
+ }
+ _ => Some(rustc_hir_pretty::attribute_to_string(&tcx, attr)),
}
} else if ALLOWED_ATTRIBUTES.contains(&attr.name_or_empty()) {
Some(
@@ -789,8 +799,7 @@ impl Item {
.collect();
// Add #[repr(...)]
- if !is_json
- && let Some(def_id) = self.def_id()
+ if let Some(def_id) = self.def_id()
&& let ItemType::Struct | ItemType::Enum | ItemType::Union = self.type_()
{
let adt = tcx.adt_def(def_id);
diff --git a/src/rustdoc-json-types/lib.rs b/src/rustdoc-json-types/lib.rs
index 44e82c7d8b1..137fe4c4c35 100644
--- a/src/rustdoc-json-types/lib.rs
+++ b/src/rustdoc-json-types/lib.rs
@@ -30,7 +30,7 @@ pub type FxHashMap<K, V> = HashMap<K, V>; // re-export for use in src/librustdoc
/// This integer is incremented with every breaking change to the API,
/// and is returned along with the JSON blob as [`Crate::format_version`].
/// Consuming code should assert that this value matches the format version(s) that it supports.
-pub const FORMAT_VERSION: u32 = 42;
+pub const FORMAT_VERSION: u32 = 43;
/// The root of the emitted JSON blob.
///
@@ -120,9 +120,23 @@ pub struct Item {
pub docs: Option<String>,
/// This mapping resolves [intra-doc links](https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md) from the docstring to their IDs
pub links: HashMap<String, Id>,
- /// Stringified versions of parsed attributes on this item.
- /// Essentially debug printed (e.g. `#[inline]` becomes something similar to `#[attr="Inline(Hint)"]`).
- /// Equivalent to the hir pretty-printing of attributes.
+ /// Attributes on this item.
+ ///
+ /// Does not include `#[deprecated]` attributes: see the [`Self::deprecation`] field instead.
+ ///
+ /// Some attributes appear in pretty-printed Rust form, regardless of their formatting
+ /// in the original source code. For example:
+ /// - `#[non_exhaustive]` and `#[must_use]` are represented as themselves.
+ /// - `#[no_mangle]` and `#[export_name]` are also represented as themselves.
+ /// - `#[repr(C)]` and other reprs also appear as themselves,
+ /// though potentially with a different order: e.g. `repr(i8, C)` may become `repr(C, i8)`.
+ /// Multiple repr attributes on the same item may be combined into an equivalent single attr.
+ ///
+ /// Other attributes may appear debug-printed. For example:
+ /// - `#[inline]` becomes something similar to `#[attr="Inline(Hint)"]`.
+ ///
+ /// As an internal implementation detail subject to change, this debug-printing format
+ /// is currently equivalent to the HIR pretty-printing of parsed attributes.
pub attrs: Vec<String>,
/// Information about the item’s deprecation, if present.
pub deprecation: Option<Deprecation>,
diff --git a/tests/rustdoc-json/attrs/repr_align.rs b/tests/rustdoc-json/attrs/repr_align.rs
index 83506737b21..c6debda7f1c 100644
--- a/tests/rustdoc-json/attrs/repr_align.rs
+++ b/tests/rustdoc-json/attrs/repr_align.rs
@@ -1,6 +1,6 @@
#![no_std]
-//@ is "$.index[?(@.name=='Aligned')].attrs" '["#[attr = Repr([ReprAlign(Align(4 bytes))])]\n"]'
+//@ is "$.index[?(@.name=='Aligned')].attrs" '["#[repr(align(4))]"]'
#[repr(align(4))]
pub struct Aligned {
a: i8,
diff --git a/tests/rustdoc-json/attrs/repr_c.rs b/tests/rustdoc-json/attrs/repr_c.rs
index 018086b3c1f..e6219413f30 100644
--- a/tests/rustdoc-json/attrs/repr_c.rs
+++ b/tests/rustdoc-json/attrs/repr_c.rs
@@ -1,16 +1,16 @@
#![no_std]
-//@ is "$.index[?(@.name=='ReprCStruct')].attrs" '["#[attr = Repr([ReprC])]\n"]'
+//@ is "$.index[?(@.name=='ReprCStruct')].attrs" '["#[repr(C)]"]'
#[repr(C)]
pub struct ReprCStruct(pub i64);
-//@ is "$.index[?(@.name=='ReprCEnum')].attrs" '["#[attr = Repr([ReprC])]\n"]'
+//@ is "$.index[?(@.name=='ReprCEnum')].attrs" '["#[repr(C)]"]'
#[repr(C)]
pub enum ReprCEnum {
First,
}
-//@ is "$.index[?(@.name=='ReprCUnion')].attrs" '["#[attr = Repr([ReprC])]\n"]'
+//@ is "$.index[?(@.name=='ReprCUnion')].attrs" '["#[repr(C)]"]'
#[repr(C)]
pub union ReprCUnion {
pub left: i64,
diff --git a/tests/rustdoc-json/attrs/repr_combination.rs b/tests/rustdoc-json/attrs/repr_combination.rs
index c3ef8becb77..0e8e2ef0d83 100644
--- a/tests/rustdoc-json/attrs/repr_combination.rs
+++ b/tests/rustdoc-json/attrs/repr_combination.rs
@@ -1,34 +1,35 @@
#![no_std]
// Combinations of `#[repr(..)]` attributes.
+// Rustdoc JSON emits normalized output, regardless of the original source.
-//@ is "$.index[?(@.name=='ReprCI8')].attrs" '["#[attr = Repr([ReprC, ReprInt(SignedInt(I8))])]\n"]'
+//@ is "$.index[?(@.name=='ReprCI8')].attrs" '["#[repr(C, i8)]"]'
#[repr(C, i8)]
pub enum ReprCI8 {
First,
}
-//@ is "$.index[?(@.name=='SeparateReprCI16')].attrs" '["#[attr = Repr([ReprC, ReprInt(SignedInt(I16))])]\n"]'
+//@ is "$.index[?(@.name=='SeparateReprCI16')].attrs" '["#[repr(C, i16)]"]'
#[repr(C)]
#[repr(i16)]
pub enum SeparateReprCI16 {
First,
}
-//@ is "$.index[?(@.name=='ReversedReprCUsize')].attrs" '["#[attr = Repr([ReprInt(UnsignedInt(Usize)), ReprC])]\n"]'
+//@ is "$.index[?(@.name=='ReversedReprCUsize')].attrs" '["#[repr(C, usize)]"]'
#[repr(usize, C)]
pub enum ReversedReprCUsize {
First,
}
-//@ is "$.index[?(@.name=='ReprCPacked')].attrs" '["#[attr = Repr([ReprC, ReprPacked(Align(1 bytes))])]\n"]'
+//@ is "$.index[?(@.name=='ReprCPacked')].attrs" '["#[repr(C, packed(1))]"]'
#[repr(C, packed)]
pub struct ReprCPacked {
a: i8,
b: i64,
}
-//@ is "$.index[?(@.name=='SeparateReprCPacked')].attrs" '["#[attr = Repr([ReprC, ReprPacked(Align(2 bytes))])]\n"]'
+//@ is "$.index[?(@.name=='SeparateReprCPacked')].attrs" '["#[repr(C, packed(2))]"]'
#[repr(C)]
#[repr(packed(2))]
pub struct SeparateReprCPacked {
@@ -36,21 +37,21 @@ pub struct SeparateReprCPacked {
b: i64,
}
-//@ is "$.index[?(@.name=='ReversedReprCPacked')].attrs" '["#[attr = Repr([ReprPacked(Align(2 bytes)), ReprC])]\n"]'
+//@ is "$.index[?(@.name=='ReversedReprCPacked')].attrs" '["#[repr(C, packed(2))]"]'
#[repr(packed(2), C)]
pub struct ReversedReprCPacked {
a: i8,
b: i64,
}
-//@ is "$.index[?(@.name=='ReprCAlign')].attrs" '["#[attr = Repr([ReprC, ReprAlign(Align(16 bytes))])]\n"]'
+//@ is "$.index[?(@.name=='ReprCAlign')].attrs" '["#[repr(C, align(16))]"]'
#[repr(C, align(16))]
pub struct ReprCAlign {
a: i8,
b: i64,
}
-//@ is "$.index[?(@.name=='SeparateReprCAlign')].attrs" '["#[attr = Repr([ReprC, ReprAlign(Align(2 bytes))])]\n"]'
+//@ is "$.index[?(@.name=='SeparateReprCAlign')].attrs" '["#[repr(C, align(2))]"]'
#[repr(C)]
#[repr(align(2))]
pub struct SeparateReprCAlign {
@@ -58,20 +59,20 @@ pub struct SeparateReprCAlign {
b: i64,
}
-//@ is "$.index[?(@.name=='ReversedReprCAlign')].attrs" '["#[attr = Repr([ReprAlign(Align(2 bytes)), ReprC])]\n"]'
+//@ is "$.index[?(@.name=='ReversedReprCAlign')].attrs" '["#[repr(C, align(2))]"]'
#[repr(align(2), C)]
pub struct ReversedReprCAlign {
a: i8,
b: i64,
}
-//@ is "$.index[?(@.name=='AlignedExplicitRepr')].attrs" '["#[attr = Repr([ReprC, ReprAlign(Align(16 bytes)), ReprInt(SignedInt(Isize))])]\n"]'
+//@ is "$.index[?(@.name=='AlignedExplicitRepr')].attrs" '["#[repr(C, align(16), isize)]"]'
#[repr(C, align(16), isize)]
pub enum AlignedExplicitRepr {
First,
}
-//@ is "$.index[?(@.name=='ReorderedAlignedExplicitRepr')].attrs" '["#[attr = Repr([ReprInt(SignedInt(Isize)), ReprC, ReprAlign(Align(16 bytes))])]\n"]'
+//@ is "$.index[?(@.name=='ReorderedAlignedExplicitRepr')].attrs" '["#[repr(C, align(16), isize)]"]'
#[repr(isize, C, align(16))]
pub enum ReorderedAlignedExplicitRepr {
First,
diff --git a/tests/rustdoc-json/attrs/repr_int_enum.rs b/tests/rustdoc-json/attrs/repr_int_enum.rs
index 206cb7835f5..9b09f341d4f 100644
--- a/tests/rustdoc-json/attrs/repr_int_enum.rs
+++ b/tests/rustdoc-json/attrs/repr_int_enum.rs
@@ -1,18 +1,18 @@
#![no_std]
-//@ is "$.index[?(@.name=='I8')].attrs" '["#[attr = Repr([ReprInt(SignedInt(I8))])]\n"]'
+//@ is "$.index[?(@.name=='I8')].attrs" '["#[repr(i8)]"]'
#[repr(i8)]
pub enum I8 {
First,
}
-//@ is "$.index[?(@.name=='I32')].attrs" '["#[attr = Repr([ReprInt(SignedInt(I32))])]\n"]'
+//@ is "$.index[?(@.name=='I32')].attrs" '["#[repr(i32)]"]'
#[repr(i32)]
pub enum I32 {
First,
}
-//@ is "$.index[?(@.name=='Usize')].attrs" '["#[attr = Repr([ReprInt(UnsignedInt(Usize))])]\n"]'
+//@ is "$.index[?(@.name=='Usize')].attrs" '["#[repr(usize)]"]'
#[repr(usize)]
pub enum Usize {
First,
diff --git a/tests/rustdoc-json/attrs/repr_packed.rs b/tests/rustdoc-json/attrs/repr_packed.rs
index d4c400f72f8..9f3fd86c4b0 100644
--- a/tests/rustdoc-json/attrs/repr_packed.rs
+++ b/tests/rustdoc-json/attrs/repr_packed.rs
@@ -1,16 +1,16 @@
#![no_std]
// Note the normalization:
-// `#[repr(packed)]` in has the implict "1" in rustdoc JSON.
-
-//@ is "$.index[?(@.name=='Packed')].attrs" '["#[attr = Repr([ReprPacked(Align(1 bytes))])]\n"]'
+// `#[repr(packed)]` in source becomes `#[repr(packed(1))]` in rustdoc JSON.
+//
+//@ is "$.index[?(@.name=='Packed')].attrs" '["#[repr(packed(1))]"]'
#[repr(packed)]
pub struct Packed {
a: i8,
b: i64,
}
-//@ is "$.index[?(@.name=='PackedAligned')].attrs" '["#[attr = Repr([ReprPacked(Align(4 bytes))])]\n"]'
+//@ is "$.index[?(@.name=='PackedAligned')].attrs" '["#[repr(packed(4))]"]'
#[repr(packed(4))]
pub struct PackedAligned {
a: i8,
diff --git a/tests/rustdoc-json/attrs/repr_transparent.rs b/tests/rustdoc-json/attrs/repr_transparent.rs
index 3f57b21dcc5..1e634ca901d 100644
--- a/tests/rustdoc-json/attrs/repr_transparent.rs
+++ b/tests/rustdoc-json/attrs/repr_transparent.rs
@@ -1,22 +1,37 @@
#![no_std]
-// Rustdoc JSON currently includes `#[repr(transparent)]`
-// even if the transparency is not part of the public API
+// Rustdoc JSON *only* includes `#[repr(transparent)]`
+// if the transparency is public API:
+// - if a non-1-ZST field exists, it has to be public
+// - otherwise, all fields are 1-ZST and at least one of them is public
//
-// https://doc.rust-lang.org/nomicon/other-reprs.html#reprtransparent
+// More info: https://doc.rust-lang.org/nomicon/other-reprs.html#reprtransparent
-//@ is "$.index[?(@.name=='Transparent')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+// Here, the non-1-ZST field is public.
+// We expect `#[repr(transparent)]` in the attributes.
+//
+//@ is "$.index[?(@.name=='Transparent')].attrs" '["#[repr(transparent)]"]'
#[repr(transparent)]
pub struct Transparent(pub i64);
-//@ is "$.index[?(@.name=='TransparentNonPub')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+// Here the non-1-ZST field isn't public, so the attribute isn't included.
+//
+//@ has "$.index[?(@.name=='TransparentNonPub')]"
+//@ is "$.index[?(@.name=='TransparentNonPub')].attrs" '[]'
#[repr(transparent)]
pub struct TransparentNonPub(i64);
-//@ is "$.index[?(@.name=='AllZst')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+// Only 1-ZST fields here, and one of them is public.
+// We expect `#[repr(transparent)]` in the attributes.
+//
+//@ is "$.index[?(@.name=='AllZst')].attrs" '["#[repr(transparent)]"]'
#[repr(transparent)]
pub struct AllZst<'a>(pub core::marker::PhantomData<&'a ()>, ());
-//@ is "$.index[?(@.name=='AllZstNotPublic')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+// Only 1-ZST fields here but none of them are public.
+// The attribute isn't included.
+//
+//@ has "$.index[?(@.name=='AllZstNotPublic')]"
+//@ is "$.index[?(@.name=='AllZstNotPublic')].attrs" '[]'
#[repr(transparent)]
pub struct AllZstNotPublic<'a>(core::marker::PhantomData<&'a ()>, ());
diff --git a/tests/rustdoc-json/enums/discriminant/struct.rs b/tests/rustdoc-json/enums/discriminant/struct.rs
index 08fb80540fa..ea669e6a0b3 100644
--- a/tests/rustdoc-json/enums/discriminant/struct.rs
+++ b/tests/rustdoc-json/enums/discriminant/struct.rs
@@ -1,5 +1,5 @@
#[repr(i32)]
-//@ is "$.index[?(@.name=='Foo')].attrs" '["#[attr = Repr([ReprInt(SignedInt(I32))])]\n"]'
+//@ is "$.index[?(@.name=='Foo')].attrs" '["#[repr(i32)]"]'
pub enum Foo {
//@ is "$.index[?(@.name=='Struct')].inner.variant.discriminant" null
//@ count "$.index[?(@.name=='Struct')].inner.variant.kind.struct.fields[*]" 0
diff --git a/tests/rustdoc-json/enums/discriminant/tuple.rs b/tests/rustdoc-json/enums/discriminant/tuple.rs
index c74e9a2c58d..1b8e791eb23 100644
--- a/tests/rustdoc-json/enums/discriminant/tuple.rs
+++ b/tests/rustdoc-json/enums/discriminant/tuple.rs
@@ -1,5 +1,5 @@
#[repr(u32)]
-//@ is "$.index[?(@.name=='Foo')].attrs" '["#[attr = Repr([ReprInt(UnsignedInt(U32))])]\n"]'
+//@ is "$.index[?(@.name=='Foo')].attrs" '["#[repr(u32)]"]'
pub enum Foo {
//@ is "$.index[?(@.name=='Tuple')].inner.variant.discriminant" null
//@ count "$.index[?(@.name=='Tuple')].inner.variant.kind.tuple[*]" 0