Rollup merge of #138569 - aDotInTheVoid:reprdoc-json, r=GuillaumeGomez

rustdoc-json: Add tests for `#[repr(...)]`

Works towards #137645 and #81359

Based on #138018, but with only the test changes. CC ```@obi1kenobi```

r? ```@GuillaumeGomez```

tests/rustdoc-json/attrs/repr_align.rs

@@ -0,0 +1,8 @@
+#![no_std]
+
+//@ is "$.index[*][?(@.name=='Aligned')].attrs" '["#[attr = Repr([ReprAlign(Align(4 bytes))])]\n"]'
+#[repr(align(4))]
+pub struct Aligned {
+    a: i8,
+    b: i64,
+}

tests/rustdoc-json/attrs/repr_c.rs

@@ -0,0 +1,18 @@
+#![no_std]
+
+//@ is "$.index[*][?(@.name=='ReprCStruct')].attrs" '["#[attr = Repr([ReprC])]\n"]'
+#[repr(C)]
+pub struct ReprCStruct(pub i64);
+
+//@ is "$.index[*][?(@.name=='ReprCEnum')].attrs" '["#[attr = Repr([ReprC])]\n"]'
+#[repr(C)]
+pub enum ReprCEnum {
+    First,
+}
+
+//@ is "$.index[*][?(@.name=='ReprCUnion')].attrs" '["#[attr = Repr([ReprC])]\n"]'
+#[repr(C)]
+pub union ReprCUnion {
+    pub left: i64,
+    pub right: u64,
+}

tests/rustdoc-json/attrs/repr_combination.rs

@@ -0,0 +1,78 @@
+#![no_std]
+
+// Combinations of `#[repr(..)]` attributes.
+
+//@ is "$.index[*][?(@.name=='ReprCI8')].attrs" '["#[attr = Repr([ReprC, ReprInt(SignedInt(I8))])]\n"]'
+#[repr(C, i8)]
+pub enum ReprCI8 {
+    First,
+}
+
+//@ is "$.index[*][?(@.name=='SeparateReprCI16')].attrs" '["#[attr = Repr([ReprC, ReprInt(SignedInt(I16))])]\n"]'
+#[repr(C)]
+#[repr(i16)]
+pub enum SeparateReprCI16 {
+    First,
+}
+
+//@ is "$.index[*][?(@.name=='ReversedReprCUsize')].attrs" '["#[attr = Repr([ReprInt(UnsignedInt(Usize)), ReprC])]\n"]'
+#[repr(usize, C)]
+pub enum ReversedReprCUsize {
+    First,
+}
+
+//@ is "$.index[*][?(@.name=='ReprCPacked')].attrs" '["#[attr = Repr([ReprC, ReprPacked(Align(1 bytes))])]\n"]'
+#[repr(C, packed)]
+pub struct ReprCPacked {
+    a: i8,
+    b: i64,
+}
+
+//@ is "$.index[*][?(@.name=='SeparateReprCPacked')].attrs" '["#[attr = Repr([ReprC, ReprPacked(Align(2 bytes))])]\n"]'
+#[repr(C)]
+#[repr(packed(2))]
+pub struct SeparateReprCPacked {
+    a: i8,
+    b: i64,
+}
+
+//@ is "$.index[*][?(@.name=='ReversedReprCPacked')].attrs" '["#[attr = Repr([ReprPacked(Align(2 bytes)), ReprC])]\n"]'
+#[repr(packed(2), C)]
+pub struct ReversedReprCPacked {
+    a: i8,
+    b: i64,
+}
+
+//@ is "$.index[*][?(@.name=='ReprCAlign')].attrs" '["#[attr = Repr([ReprC, ReprAlign(Align(16 bytes))])]\n"]'
+#[repr(C, align(16))]
+pub struct ReprCAlign {
+    a: i8,
+    b: i64,
+}
+
+//@ is "$.index[*][?(@.name=='SeparateReprCAlign')].attrs" '["#[attr = Repr([ReprC, ReprAlign(Align(2 bytes))])]\n"]'
+#[repr(C)]
+#[repr(align(2))]
+pub struct SeparateReprCAlign {
+    a: i8,
+    b: i64,
+}
+
+//@ is "$.index[*][?(@.name=='ReversedReprCAlign')].attrs" '["#[attr = Repr([ReprAlign(Align(2 bytes)), ReprC])]\n"]'
+#[repr(align(2), C)]
+pub struct ReversedReprCAlign {
+    a: i8,
+    b: i64,
+}
+
+//@ is "$.index[*][?(@.name=='AlignedExplicitRepr')].attrs" '["#[attr = Repr([ReprC, ReprAlign(Align(16 bytes)), ReprInt(SignedInt(Isize))])]\n"]'
+#[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"]'
+#[repr(isize, C, align(16))]
+pub enum ReorderedAlignedExplicitRepr {
+    First,
+}

tests/rustdoc-json/attrs/repr_int_enum.rs

@@ -0,0 +1,19 @@
+#![no_std]
+
+//@ is "$.index[*][?(@.name=='I8')].attrs" '["#[attr = Repr([ReprInt(SignedInt(I8))])]\n"]'
+#[repr(i8)]
+pub enum I8 {
+    First,
+}
+
+//@ is "$.index[*][?(@.name=='I32')].attrs" '["#[attr = Repr([ReprInt(SignedInt(I32))])]\n"]'
+#[repr(i32)]
+pub enum I32 {
+    First,
+}
+
+//@ is "$.index[*][?(@.name=='Usize')].attrs" '["#[attr = Repr([ReprInt(UnsignedInt(Usize))])]\n"]'
+#[repr(usize)]
+pub enum Usize {
+    First,
+}

tests/rustdoc-json/attrs/repr_packed.rs

@@ -0,0 +1,18 @@
+#![no_std]
+
+// Note the normalization:
+// `#[repr(packed)]` in has the implict "1" in rustdoc JSON.
+
+//@ is "$.index[*][?(@.name=='Packed')].attrs" '["#[attr = Repr([ReprPacked(Align(1 bytes))])]\n"]'
+#[repr(packed)]
+pub struct Packed {
+    a: i8,
+    b: i64,
+}
+
+//@ is "$.index[*][?(@.name=='PackedAligned')].attrs" '["#[attr = Repr([ReprPacked(Align(4 bytes))])]\n"]'
+#[repr(packed(4))]
+pub struct PackedAligned {
+    a: i8,
+    b: i64,
+}

tests/rustdoc-json/attrs/repr_transparent.rs

@@ -0,0 +1,22 @@
+#![no_std]
+
+// Rustdoc JSON currently includes `#[repr(transparent)]`
+// even if the transparency is not part of the public API
+//
+// https://doc.rust-lang.org/nomicon/other-reprs.html#reprtransparent
+
+//@ is "$.index[*][?(@.name=='Transparent')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+#[repr(transparent)]
+pub struct Transparent(pub i64);
+
+//@ is "$.index[*][?(@.name=='TransparentNonPub')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+#[repr(transparent)]
+pub struct TransparentNonPub(i64);
+
+//@ is "$.index[*][?(@.name=='AllZst')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+#[repr(transparent)]
+pub struct AllZst<'a>(pub core::marker::PhantomData<&'a ()>, ());
+
+//@ is "$.index[*][?(@.name=='AllZstNotPublic')].attrs" '["#[attr = Repr([ReprTransparent])]\n"]'
+#[repr(transparent)]
+pub struct AllZstNotPublic<'a>(core::marker::PhantomData<&'a ()>, ());