mirror of https://github.com/rust-lang/rust
48 lines
1.4 KiB
Rust
48 lines
1.4 KiB
Rust
//@ test-mir-pass: EarlyOtherwiseBranch
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//@ compile-flags: -Zmir-enable-passes=+UnreachableEnumBranching
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// Tests various cases that the `early_otherwise_branch` opt should *not* optimize
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// From #78496
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enum E<'a> {
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Empty,
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Some(&'a E<'a>),
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}
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// EMIT_MIR early_otherwise_branch_soundness.no_downcast.EarlyOtherwiseBranch.diff
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fn no_downcast(e: &E) -> u32 {
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// CHECK-LABEL: fn no_downcast(
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// CHECK: bb0: {
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// CHECK: [[LOCAL1:_.*]] = discriminant({{.*}});
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// CHECK-NOT: Ne
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// CHECK-NOT: discriminant
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// CHECK: switchInt(move [[LOCAL1]]) -> [
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// CHECK-NEXT: }
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if let E::Some(E::Some(_)) = e { 1 } else { 2 }
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}
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// SAFETY: if `a` is `Some`, `b` must point to a valid, initialized value
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// EMIT_MIR early_otherwise_branch_soundness.no_deref_ptr.EarlyOtherwiseBranch.diff
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unsafe fn no_deref_ptr(a: Option<i32>, b: *const Option<i32>) -> i32 {
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// CHECK-LABEL: fn no_deref_ptr(
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// CHECK: bb0: {
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// CHECK: [[LOCAL1:_.*]] = discriminant({{.*}});
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// CHECK-NOT: Ne
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// CHECK-NOT: discriminant
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// CHECK: switchInt(move [[LOCAL1]]) -> [
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// CHECK-NEXT: }
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match a {
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// `*b` being correct depends on `a == Some(_)`
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Some(_) => match *b {
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Some(v) => v,
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_ => 0,
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},
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_ => 0,
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}
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}
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fn main() {
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no_downcast(&E::Empty);
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unsafe { no_deref_ptr(None, std::ptr::null()) };
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}
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