Auto merge of #60463 - mjbshaw:transparent, r=varkor,rkruppe

Implement RFC 2645 (transparent enums and unions)

Tracking issue: #60405

4 files changed, 190 insertions, 28 deletions

diff --git a/src/test/codegen/repr-transparent-aggregates-1.rs b/src/test/codegen/repr-transparent-aggregates-1.rs
index fb88f2a69ca..e7c4b6193bc 100644
--- a/src/test/codegen/repr-transparent-aggregates-1.rs
+++ b/src/test/codegen/repr-transparent-aggregates-1.rs
@@ -1,4 +1,5 @@
 // compile-flags: -C no-prepopulate-passes
+// ignore-tidy-linelength
 
 // ignore-arm
 // ignore-mips
@@ -7,36 +8,76 @@
 // ignore-powerpc64
 // See repr-transparent.rs
 
+#![feature(transparent_enums, transparent_unions)]
+
 #![crate_type="lib"]
 
 
+#[derive(Clone, Copy)]
 #[repr(C)]
-pub struct Big([u32; 16]);
+pub struct BigS([u32; 16]);
+
+#[repr(transparent)]
+pub struct TsBigS(BigS);
+
+#[repr(transparent)]
+pub union TuBigS {
+    field: BigS,
+}
 
 #[repr(transparent)]
-pub struct BigW(Big);
+pub enum TeBigS {
+    Variant(BigS),
+}
+
+// CHECK: define void @test_BigS(%BigS* [[BIGS_RET_ATTRS:.*]], %BigS* [[BIGS_ARG_ATTRS:.*]])
+#[no_mangle]
+pub extern fn test_BigS(_: BigS) -> BigS { loop {} }
+
+// CHECK: define void @test_TsBigS(%TsBigS* [[BIGS_RET_ATTRS]], %TsBigS* [[BIGS_ARG_ATTRS]])
+#[no_mangle]
+pub extern fn test_TsBigS(_: TsBigS) -> TsBigS { loop {} }
 
-// CHECK: define void @test_Big(%Big* [[BIG_RET_ATTRS:.*]], %Big* [[BIG_ARG_ATTRS:.*]])
+// CHECK: define void @test_TuBigS(%TuBigS* [[BIGS_RET_ATTRS]], %TuBigS* [[BIGS_ARG_ATTRS]])
 #[no_mangle]
-pub extern fn test_Big(_: Big) -> Big { loop {} }
+pub extern fn test_TuBigS(_: TuBigS) -> TuBigS { loop {} }
 
-// CHECK: define void @test_BigW(%BigW* [[BIG_RET_ATTRS]], %BigW* [[BIG_ARG_ATTRS]])
+// CHECK: define void @test_TeBigS(%"TeBigS::Variant"* [[BIGS_RET_ATTRS]], %"TeBigS::Variant"* [[BIGS_ARG_ATTRS]])
 #[no_mangle]
-pub extern fn test_BigW(_: BigW) -> BigW { loop {} }
+pub extern fn test_TeBigS(_: TeBigS) -> TeBigS { loop {} }
 
 
+#[derive(Clone, Copy)]
 #[repr(C)]
 pub union BigU {
     foo: [u32; 16],
 }
 
 #[repr(transparent)]
-pub struct BigUw(BigU);
+pub struct TsBigU(BigU);
+
+#[repr(transparent)]
+pub union TuBigU {
+    field: BigU,
+}
+
+#[repr(transparent)]
+pub enum TeBigU {
+    Variant(BigU),
+}
 
 // CHECK: define void @test_BigU(%BigU* [[BIGU_RET_ATTRS:.*]], %BigU* [[BIGU_ARG_ATTRS:.*]])
 #[no_mangle]
 pub extern fn test_BigU(_: BigU) -> BigU { loop {} }
 
-// CHECK: define void @test_BigUw(%BigUw* [[BIGU_RET_ATTRS]], %BigUw* [[BIGU_ARG_ATTRS]])
+// CHECK: define void @test_TsBigU(%TsBigU* [[BIGU_RET_ATTRS:.*]], %TsBigU* [[BIGU_ARG_ATTRS]])
+#[no_mangle]
+pub extern fn test_TsBigU(_: TsBigU) -> TsBigU { loop {} }
+
+// CHECK: define void @test_TuBigU(%TuBigU* [[BIGU_RET_ATTRS]], %TuBigU* [[BIGU_ARG_ATTRS]])
+#[no_mangle]
+pub extern fn test_TuBigU(_: TuBigU) -> TuBigU { loop {} }
+
+// CHECK: define void @test_TeBigU(%"TeBigU::Variant"* [[BIGU_RET_ATTRS]], %"TeBigU::Variant"* [[BIGU_ARG_ATTRS]])
 #[no_mangle]
-pub extern fn test_BigUw(_: BigUw) -> BigUw { loop {} }
+pub extern fn test_TeBigU(_: TeBigU) -> TeBigU { loop {} }
diff --git a/src/test/codegen/repr-transparent-aggregates-2.rs b/src/test/codegen/repr-transparent-aggregates-2.rs
index 6c628ac035f..5521c3c849f 100644
--- a/src/test/codegen/repr-transparent-aggregates-2.rs
+++ b/src/test/codegen/repr-transparent-aggregates-2.rs
@@ -14,36 +14,76 @@
 // ignore-x86_64
 // See repr-transparent.rs
 
+#![feature(transparent_enums, transparent_unions)]
+
 #![crate_type="lib"]
 
 
+#[derive(Clone, Copy)]
 #[repr(C)]
-pub struct Big([u32; 16]);
+pub struct BigS([u32; 16]);
+
+#[repr(transparent)]
+pub struct TsBigS(BigS);
+
+#[repr(transparent)]
+pub union TuBigS {
+    field: BigS,
+}
 
 #[repr(transparent)]
-pub struct BigW(Big);
+pub enum TeBigS {
+    Variant(BigS),
+}
+
+// CHECK: define void @test_BigS(%BigS* [[BIGS_RET_ATTRS:.*]], [16 x i32]
+#[no_mangle]
+pub extern fn test_BigS(_: BigS) -> BigS { loop {} }
+
+// CHECK: define void @test_TsBigS(%TsBigS* [[BIGS_RET_ATTRS]], [16 x i32]
+#[no_mangle]
+pub extern fn test_TsBigS(_: TsBigS) -> TsBigS { loop {} }
 
-// CHECK: define void @test_Big(%Big* [[BIG_RET_ATTRS:.*]], [16 x i32]
+// CHECK: define void @test_TuBigS(%TuBigS* [[BIGS_RET_ATTRS]], [16 x i32]
 #[no_mangle]
-pub extern fn test_Big(_: Big) -> Big { loop {} }
+pub extern fn test_TuBigS(_: TuBigS) -> TuBigS { loop {} }
 
-// CHECK: define void @test_BigW(%BigW* [[BIG_RET_ATTRS]], [16 x i32]
+// CHECK: define void @test_TeBigS(%"TeBigS::Variant"* [[BIGS_RET_ATTRS]], [16 x i32]
 #[no_mangle]
-pub extern fn test_BigW(_: BigW) -> BigW { loop {} }
+pub extern fn test_TeBigS(_: TeBigS) -> TeBigS { loop {} }
 
 
+#[derive(Clone, Copy)]
 #[repr(C)]
 pub union BigU {
     foo: [u32; 16],
 }
 
 #[repr(transparent)]
-pub struct BigUw(BigU);
+pub struct TsBigU(BigU);
+
+#[repr(transparent)]
+pub union TuBigU {
+    field: BigU,
+}
+
+#[repr(transparent)]
+pub enum TeBigU {
+    Variant(BigU),
+}
 
 // CHECK: define void @test_BigU(%BigU* [[BIGU_RET_ATTRS:.*]], [16 x i32]
 #[no_mangle]
 pub extern fn test_BigU(_: BigU) -> BigU { loop {} }
 
-// CHECK: define void @test_BigUw(%BigUw* [[BIGU_RET_ATTRS]], [16 x i32]
+// CHECK: define void @test_TsBigU(%TsBigU* [[BIGU_RET_ATTRS:.*]], [16 x i32]
+#[no_mangle]
+pub extern fn test_TsBigU(_: TsBigU) -> TsBigU { loop {} }
+
+// CHECK: define void @test_TuBigU(%TuBigU* [[BIGU_RET_ATTRS]], [16 x i32]
+#[no_mangle]
+pub extern fn test_TuBigU(_: TuBigU) -> TuBigU { loop {} }
+
+// CHECK: define void @test_TeBigU(%"TeBigU::Variant"* [[BIGU_RET_ATTRS]], [16 x i32]
 #[no_mangle]
-pub extern fn test_BigUw(_: BigUw) -> BigUw { loop {} }
+pub extern fn test_TeBigU(_: TeBigU) -> TeBigU { loop {} }
diff --git a/src/test/codegen/repr-transparent-aggregates-3.rs b/src/test/codegen/repr-transparent-aggregates-3.rs
index cd740dc9b82..1a59c9b48b9 100644
--- a/src/test/codegen/repr-transparent-aggregates-3.rs
+++ b/src/test/codegen/repr-transparent-aggregates-3.rs
@@ -3,36 +3,76 @@
 // only-mips64
 // See repr-transparent.rs
 
+#![feature(transparent_enums, transparent_unions)]
+
 #![crate_type="lib"]
 
 
+#[derive(Clone, Copy)]
 #[repr(C)]
-pub struct Big([u32; 16]);
+pub struct BigS([u32; 16]);
+
+#[repr(transparent)]
+pub struct TsBigS(BigS);
+
+#[repr(transparent)]
+pub union TuBigS {
+    field: BigS,
+}
 
 #[repr(transparent)]
-pub struct BigW(Big);
+pub enum TeBigS {
+    Variant(BigS),
+}
+
+// CHECK: define void @test_BigS(%BigS* [[BIGS_RET_ATTRS:.*]], [8 x i64]
+#[no_mangle]
+pub extern fn test_BigS(_: BigS) -> BigS { loop {} }
+
+// CHECK: define void @test_TsBigS(%TsBigS* [[BIGS_RET_ATTRS]], [8 x i64]
+#[no_mangle]
+pub extern fn test_TsBigS(_: TsBigS) -> TsBigS { loop {} }
 
-// CHECK: define void @test_Big(%Big* [[BIG_RET_ATTRS:.*]], [8 x i64]
+// CHECK: define void @test_TuBigS(%TuBigS* [[BIGS_RET_ATTRS]], [8 x i64]
 #[no_mangle]
-pub extern fn test_Big(_: Big) -> Big { loop {} }
+pub extern fn test_TuBigS(_: TuBigS) -> TuBigS { loop {} }
 
-// CHECK: define void @test_BigW(%BigW* [[BIG_RET_ATTRS]], [8 x i64]
+// CHECK: define void @test_TeBigS(%"TeBigS::Variant"* [[BIGS_RET_ATTRS]], [8 x i64]
 #[no_mangle]
-pub extern fn test_BigW(_: BigW) -> BigW { loop {} }
+pub extern fn test_TeBigS(_: TeBigS) -> TeBigS { loop {} }
 
 
+#[derive(Clone, Copy)]
 #[repr(C)]
 pub union BigU {
     foo: [u32; 16],
 }
 
 #[repr(transparent)]
-pub struct BigUw(BigU);
+pub struct TsBigU(BigU);
+
+#[repr(transparent)]
+pub union TuBigU {
+    field: BigU,
+}
+
+#[repr(transparent)]
+pub enum TeBigU {
+    Variant(BigU),
+}
 
 // CHECK: define void @test_BigU(%BigU* [[BIGU_RET_ATTRS:.*]], [8 x i64]
 #[no_mangle]
 pub extern fn test_BigU(_: BigU) -> BigU { loop {} }
 
-// CHECK: define void @test_BigUw(%BigUw* [[BIGU_RET_ATTRS]], [8 x i64]
+// CHECK: define void @test_TsBigU(%TsBigU* [[BIGU_RET_ATTRS:.*]], [8 x i64]
+#[no_mangle]
+pub extern fn test_TsBigU(_: TsBigU) -> TsBigU { loop {} }
+
+// CHECK: define void @test_TuBigU(%TuBigU* [[BIGU_RET_ATTRS]], [8 x i64]
+#[no_mangle]
+pub extern fn test_TuBigU(_: TuBigU) -> TuBigU { loop {} }
+
+// CHECK: define void @test_TeBigU(%"TeBigU::Variant"* [[BIGU_RET_ATTRS]], [8 x i64]
 #[no_mangle]
-pub extern fn test_BigUw(_: BigUw) -> BigUw { loop {} }
+pub extern fn test_TeBigU(_: TeBigU) -> TeBigU { loop {} }
diff --git a/src/test/codegen/repr-transparent.rs b/src/test/codegen/repr-transparent.rs
index fd655261ab8..c9f38375658 100644
--- a/src/test/codegen/repr-transparent.rs
+++ b/src/test/codegen/repr-transparent.rs
@@ -1,13 +1,16 @@
 // compile-flags: -C no-prepopulate-passes
 
 #![crate_type="lib"]
-#![feature(repr_simd)]
+#![feature(repr_simd, transparent_enums, transparent_unions)]
 
 use std::marker::PhantomData;
 
+#[derive(Copy, Clone)]
 pub struct Zst1;
+#[derive(Copy, Clone)]
 pub struct Zst2(());
 
+#[derive(Copy, Clone)]
 #[repr(transparent)]
 pub struct F32(f32);
 
@@ -112,6 +115,44 @@ pub struct StructWithProjection(<f32 as Mirror>::It);
 #[no_mangle]
 pub extern fn test_Projection(_: StructWithProjection) -> StructWithProjection { loop {} }
 
+#[repr(transparent)]
+pub enum EnumF32 {
+    Variant(F32)
+}
+
+// CHECK: define float @test_EnumF32(float %arg0)
+#[no_mangle]
+pub extern fn test_EnumF32(_: EnumF32) -> EnumF32 { loop {} }
+
+#[repr(transparent)]
+pub enum EnumF32WithZsts {
+    Variant(Zst1, F32, Zst2)
+}
+
+// CHECK: define float @test_EnumF32WithZsts(float %arg0)
+#[no_mangle]
+pub extern fn test_EnumF32WithZsts(_: EnumF32WithZsts) -> EnumF32WithZsts { loop {} }
+
+#[repr(transparent)]
+pub union UnionF32 {
+    field: F32,
+}
+
+// CHECK: define float @test_UnionF32(float %arg0)
+#[no_mangle]
+pub extern fn test_UnionF32(_: UnionF32) -> UnionF32 { loop {} }
+
+#[repr(transparent)]
+pub union UnionF32WithZsts {
+    zst1: Zst1,
+    field: F32,
+    zst2: Zst2,
+}
+
+// CHECK: define float @test_UnionF32WithZsts(float %arg0)
+#[no_mangle]
+pub extern fn test_UnionF32WithZsts(_: UnionF32WithZsts) -> UnionF32WithZsts { loop {} }
+
 
 // All that remains to be tested are aggregates. They are tested in separate files called repr-
 // transparent-*.rs  with `only-*` or `ignore-*` directives, because the expected LLVM IR