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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/mir/mir_adt_construction.rs | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/src/test/ui/mir/mir_adt_construction.rs b/src/test/ui/mir/mir_adt_construction.rs new file mode 100644 index 000000000..9fb5896de --- /dev/null +++ b/src/test/ui/mir/mir_adt_construction.rs @@ -0,0 +1,92 @@ +// run-pass +use std::fmt; + +#[repr(C)] +enum CEnum { + Hello = 30, + World = 60 +} + +fn test1(c: CEnum) -> i32 { + let c2 = CEnum::Hello; + match (c, c2) { + (CEnum::Hello, CEnum::Hello) => 42, + (CEnum::World, CEnum::Hello) => 0, + _ => 1 + } +} + +#[repr(packed)] +struct Pakd { + a: u64, + b: u32, + c: u16, + d: u8, + e: () +} + +// It is unsafe to use #[derive(Debug)] on a packed struct because the code generated by the derive +// macro takes references to the fields instead of accessing them directly. +impl fmt::Debug for Pakd { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + // It's important that we load the fields into locals by-value here. This will do safe + // unaligned loads into the locals, then pass references to the properly-aligned locals to + // the formatting code. + let Pakd { a, b, c, d, e } = *self; + f.debug_struct("Pakd") + .field("a", &a) + .field("b", &b) + .field("c", &c) + .field("d", &d) + .field("e", &e) + .finish() + } +} + +// It is unsafe to use #[derive(PartialEq)] on a packed struct because the code generated by the +// derive macro takes references to the fields instead of accessing them directly. +impl PartialEq for Pakd { + fn eq(&self, other: &Pakd) -> bool { + self.a == other.a && + self.b == other.b && + self.c == other.c && + self.d == other.d && + self.e == other.e + } +} + +impl Drop for Pakd { + fn drop(&mut self) {} +} + +fn test2() -> Pakd { + Pakd { a: 42, b: 42, c: 42, d: 42, e: () } +} + +#[derive(PartialEq, Debug)] +struct TupleLike(u64, u32); + +fn test3() -> TupleLike { + TupleLike(42, 42) +} + +fn test4(x: fn(u64, u32) -> TupleLike) -> (TupleLike, TupleLike) { + let y = TupleLike; + (x(42, 84), y(42, 84)) +} + +fn test5(x: fn(u32) -> Option<u32>) -> (Option<u32>, Option<u32>) { + let y = Some; + (x(42), y(42)) +} + +fn main() { + assert_eq!(test1(CEnum::Hello), 42); + assert_eq!(test1(CEnum::World), 0); + assert_eq!(test2(), Pakd { a: 42, b: 42, c: 42, d: 42, e: () }); + assert_eq!(test3(), TupleLike(42, 42)); + let t4 = test4(TupleLike); + assert_eq!(t4.0, t4.1); + let t5 = test5(Some); + assert_eq!(t5.0, t5.1); +} |