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90 lines
2.3 KiB
Rust
90 lines
2.3 KiB
Rust
// unit-test: UninhabitedEnumBranching
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enum Empty {}
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// test matching an enum with uninhabited variants
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enum Test1 {
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A(Empty),
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B(Empty),
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C,
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}
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// test an enum where the discriminants don't match the variant indexes
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// (the optimization should do nothing here)
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enum Test2 {
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D = 4,
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E = 5,
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}
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// test matching an enum with uninhabited variants and multiple inhabited
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enum Test3 {
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A(Empty),
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B(Empty),
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C,
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D,
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}
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struct Plop {
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xx: u32,
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test3: Test3,
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}
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// EMIT_MIR uninhabited_enum_branching.simple.UninhabitedEnumBranching.diff
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fn simple() {
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// CHECK-LABEL: fn simple(
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// CHECK: [[discr:_.*]] = discriminant(
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// CHECK: switchInt(move [[discr]]) -> [0: [[unreachable:bb.*]], 1: [[unreachable]], 2: bb2, otherwise: [[unreachable]]];
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// CHECK: [[unreachable]]: {
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// CHECK-NEXT: unreachable;
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match Test1::C {
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Test1::A(_) => "A(Empty)",
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Test1::B(_) => "B(Empty)",
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Test1::C => "C",
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};
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}
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// EMIT_MIR uninhabited_enum_branching.custom_discriminant.UninhabitedEnumBranching.diff
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fn custom_discriminant() {
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// CHECK-LABEL: fn custom_discriminant(
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// CHECK: [[discr:_.*]] = discriminant(
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// CHECK: switchInt(move [[discr]]) -> [4: bb3, 5: bb2, otherwise: bb5];
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// CHECK: bb5: {
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// CHECK-NEXT: unreachable;
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match Test2::D {
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Test2::D => "D",
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Test2::E => "E",
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};
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}
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// EMIT_MIR uninhabited_enum_branching.byref.UninhabitedEnumBranching.diff
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fn byref() {
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// CHECK-LABEL: fn byref(
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let plop = Plop { xx: 51, test3: Test3::C };
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// CHECK: [[ref_discr:_.*]] = discriminant((*
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// CHECK: switchInt(move [[ref_discr]]) -> [0: [[unreachable:bb.*]], 1: [[unreachable]], 2: bb5, 3: bb2, otherwise: [[unreachable]]];
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match &plop.test3 {
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Test3::A(_) => "A(Empty)",
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Test3::B(_) => "B(Empty)",
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Test3::C => "C",
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Test3::D => "D",
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};
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// CHECK: [[discr:_.*]] = discriminant(
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// CHECK: switchInt(move [[discr]]) -> [0: [[unreachable]], 1: [[unreachable]], 2: bb10, 3: bb7, otherwise: [[unreachable]]];
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match plop.test3 {
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Test3::A(_) => "A(Empty)",
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Test3::B(_) => "B(Empty)",
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Test3::C => "C",
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Test3::D => "D",
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};
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// CHECK: [[unreachable]]: {
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// CHECK-NEXT: unreachable;
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}
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fn main() {
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simple();
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custom_discriminant();
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byref();
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}
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