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Disable field reordering #38523

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merged 1 commit into from
Dec 24, 2016
+36 −36
Merged

Disable field reordering #38523

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4 changes: 4 additions & 0 deletions src/librustc/ty/layout.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -575,6 +575,10 @@ impl<'a, 'gcx, 'tcx> Struct {
});
}

// Disable field reordering until we can decide what to do.
// The odd pattern here avoids a warning about the value never being read.
if can_optimize { can_optimize = false }

let (optimize, sort_ascending) = match kind {
StructKind::AlwaysSizedUnivariant => (can_optimize, false),
StructKind::MaybeUnsizedUnivariant => (can_optimize, false),
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7 changes: 0 additions & 7 deletions src/test/run-pass/type-sizes.rs
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Expand Up @@ -31,10 +31,6 @@ enum e3 {
a([u16; 0], u8), b
}

// Test struct field reordering to make sure it actually reorders.
struct WillOptimize1(u8, u16, u8);
struct WillOptimize2 { a: u8, b: u16, c: u8}

pub fn main() {
assert_eq!(size_of::<u8>(), 1 as usize);
assert_eq!(size_of::<u32>(), 4 as usize);
Expand All @@ -58,7 +54,4 @@ pub fn main() {
assert_eq!(size_of::<e1>(), 8 as usize);
assert_eq!(size_of::<e2>(), 8 as usize);
assert_eq!(size_of::<e3>(), 4 as usize);

assert_eq!(size_of::<WillOptimize1>(), 4);
assert_eq!(size_of::<WillOptimize2>(), 4);
}
35 changes: 19 additions & 16 deletions src/test/ui/print_type_sizes/nullable.stdout
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Original file line number Diff line number Diff line change
@@ -1,22 +1,25 @@
print-type-size type: `IndirectNonZero<u32>`: 12 bytes, alignment: 4 bytes
print-type-size field `.nested`: 8 bytes
print-type-size field `.post`: 2 bytes
print-type-size type: `IndirectNonZero<u32>`: 20 bytes, alignment: 4 bytes
print-type-size field `.pre`: 1 bytes
print-type-size end padding: 1 bytes
print-type-size type: `MyOption<IndirectNonZero<u32>>`: 12 bytes, alignment: 4 bytes
print-type-size variant `Some`: 12 bytes
print-type-size field `.0`: 12 bytes
print-type-size type: `EmbeddedDiscr`: 8 bytes, alignment: 4 bytes
print-type-size variant `Record`: 7 bytes
print-type-size field `.val`: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size field `.pre`: 1 bytes
print-type-size end padding: 1 bytes
print-type-size type: `NestedNonZero<u32>`: 8 bytes, alignment: 4 bytes
print-type-size field `.val`: 4 bytes
print-type-size padding: 3 bytes
print-type-size field `.nested`: 12 bytes, alignment: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size end padding: 2 bytes
print-type-size type: `MyOption<IndirectNonZero<u32>>`: 20 bytes, alignment: 4 bytes
print-type-size variant `Some`: 20 bytes
print-type-size field `.0`: 20 bytes
print-type-size type: `EmbeddedDiscr`: 12 bytes, alignment: 4 bytes
print-type-size variant `Record`: 10 bytes
print-type-size field `.pre`: 1 bytes
print-type-size padding: 3 bytes
print-type-size field `.val`: 4 bytes, alignment: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size end padding: 2 bytes
print-type-size type: `NestedNonZero<u32>`: 12 bytes, alignment: 4 bytes
print-type-size field `.pre`: 1 bytes
print-type-size end padding: 1 bytes
print-type-size padding: 3 bytes
print-type-size field `.val`: 4 bytes, alignment: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size end padding: 2 bytes
print-type-size type: `MyOption<core::nonzero::NonZero<u32>>`: 4 bytes, alignment: 4 bytes
print-type-size variant `Some`: 4 bytes
print-type-size field `.0`: 4 bytes
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10 changes: 6 additions & 4 deletions src/test/ui/print_type_sizes/packed.stdout
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Original file line number Diff line number Diff line change
@@ -1,11 +1,13 @@
print-type-size type: `Padded`: 12 bytes, alignment: 4 bytes
print-type-size field `.g`: 4 bytes
print-type-size field `.h`: 2 bytes
print-type-size type: `Padded`: 16 bytes, alignment: 4 bytes
print-type-size field `.a`: 1 bytes
print-type-size field `.b`: 1 bytes
print-type-size padding: 2 bytes
print-type-size field `.g`: 4 bytes, alignment: 4 bytes
print-type-size field `.c`: 1 bytes
print-type-size padding: 1 bytes
print-type-size field `.h`: 2 bytes, alignment: 2 bytes
print-type-size field `.d`: 1 bytes
print-type-size end padding: 2 bytes
print-type-size end padding: 3 bytes
print-type-size type: `Packed`: 10 bytes, alignment: 1 bytes
print-type-size field `.a`: 1 bytes
print-type-size field `.b`: 1 bytes
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16 changes: 7 additions & 9 deletions src/test/ui/print_type_sizes/padding.stdout
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Original file line number Diff line number Diff line change
@@ -1,12 +1,10 @@
print-type-size type: `E1`: 12 bytes, alignment: 4 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `A`: 7 bytes
print-type-size discriminant: 4 bytes
print-type-size variant `A`: 5 bytes
print-type-size field `.0`: 4 bytes
print-type-size field `.1`: 1 bytes
print-type-size padding: 2 bytes
print-type-size field `.0`: 4 bytes, alignment: 4 bytes
print-type-size variant `B`: 11 bytes
print-type-size padding: 3 bytes
print-type-size field `.0`: 8 bytes, alignment: 4 bytes
print-type-size variant `B`: 8 bytes
print-type-size field `.0`: 8 bytes
print-type-size type: `E2`: 12 bytes, alignment: 4 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `A`: 7 bytes
Expand All @@ -17,7 +15,7 @@ print-type-size variant `B`: 11 bytes
print-type-size padding: 3 bytes
print-type-size field `.0`: 8 bytes, alignment: 4 bytes
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.g`: 4 bytes
print-type-size field `.a`: 1 bytes
print-type-size field `.b`: 1 bytes
print-type-size end padding: 2 bytes
print-type-size padding: 2 bytes
print-type-size field `.g`: 4 bytes, alignment: 4 bytes