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645c0fddd2
Previously, it was only put on scalars with range validity invariants like bool, was uninit was obviously invalid for those. Since then, we have normatively declared all uninit primitives to be undefined behavior and can therefore put `noundef` on them. The remaining concern was the `mem::uninitialized` function, which cause quite a lot of UB in the older parts of the ecosystem. This function now doesn't return uninit values anymore, making users of it safe from this change. The only real sources of UB where people could encounter uninit primitives are `MaybeUninit::uninit().assume_init()`, which has always be clear in the docs about being UB and from heap allocations (like reading from the spare capacity of a vec. This is hopefully rare enough to not break anything.
110 lines
3.0 KiB
Rust
110 lines
3.0 KiB
Rust
// compile-flags: -Copt-level=1
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// only-x86_64
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#![crate_type = "lib"]
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// Check each of the 3 cases for `codegen_get_discr`.
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// Case 0: One tagged variant.
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pub enum Enum0 {
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A(bool),
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B,
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}
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// CHECK: define noundef i8 @match0{{.*}}
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// CHECK-NEXT: start:
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// CHECK-NEXT: %1 = icmp eq i8 %0, 2
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// CHECK-NEXT: %2 = and i8 %0, 1
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// CHECK-NEXT: %.0 = select i1 %1, i8 13, i8 %2
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#[no_mangle]
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pub fn match0(e: Enum0) -> u8 {
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use Enum0::*;
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match e {
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A(b) => b as u8,
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B => 13,
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}
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}
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// Case 1: Niche values are on a boundary for `range`.
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pub enum Enum1 {
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A(bool),
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B,
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C,
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}
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// CHECK: define noundef i8 @match1{{.*}}
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// CHECK-NEXT: start:
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// CHECK-NEXT: [[DISCR:%.*]] = {{.*}}call i8 @llvm.usub.sat.i8(i8 %0, i8 1)
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// CHECK-NEXT: switch i8 [[DISCR]], label {{.*}} [
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#[no_mangle]
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pub fn match1(e: Enum1) -> u8 {
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use Enum1::*;
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match e {
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A(b) => b as u8,
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B => 13,
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C => 100,
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}
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}
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// Case 2: Special cases don't apply.
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pub enum X {
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_2=2, _3, _4, _5, _6, _7, _8, _9, _10, _11,
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_12, _13, _14, _15, _16, _17, _18, _19, _20,
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_21, _22, _23, _24, _25, _26, _27, _28, _29,
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_30, _31, _32, _33, _34, _35, _36, _37, _38,
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_39, _40, _41, _42, _43, _44, _45, _46, _47,
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_48, _49, _50, _51, _52, _53, _54, _55, _56,
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_57, _58, _59, _60, _61, _62, _63, _64, _65,
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_66, _67, _68, _69, _70, _71, _72, _73, _74,
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_75, _76, _77, _78, _79, _80, _81, _82, _83,
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_84, _85, _86, _87, _88, _89, _90, _91, _92,
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_93, _94, _95, _96, _97, _98, _99, _100, _101,
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_102, _103, _104, _105, _106, _107, _108, _109,
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_110, _111, _112, _113, _114, _115, _116, _117,
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_118, _119, _120, _121, _122, _123, _124, _125,
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_126, _127, _128, _129, _130, _131, _132, _133,
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_134, _135, _136, _137, _138, _139, _140, _141,
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_142, _143, _144, _145, _146, _147, _148, _149,
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_150, _151, _152, _153, _154, _155, _156, _157,
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_158, _159, _160, _161, _162, _163, _164, _165,
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_166, _167, _168, _169, _170, _171, _172, _173,
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_174, _175, _176, _177, _178, _179, _180, _181,
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_182, _183, _184, _185, _186, _187, _188, _189,
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_190, _191, _192, _193, _194, _195, _196, _197,
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_198, _199, _200, _201, _202, _203, _204, _205,
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_206, _207, _208, _209, _210, _211, _212, _213,
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_214, _215, _216, _217, _218, _219, _220, _221,
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_222, _223, _224, _225, _226, _227, _228, _229,
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_230, _231, _232, _233, _234, _235, _236, _237,
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_238, _239, _240, _241, _242, _243, _244, _245,
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_246, _247, _248, _249, _250, _251, _252, _253,
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}
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pub enum Enum2 {
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A(X),
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B,
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C,
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D,
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E,
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}
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// CHECK: define noundef i8 @match2{{.*}}
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// CHECK-NEXT: start:
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// CHECK-NEXT: %1 = add i8 %0, 2
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// CHECK-NEXT: %2 = zext i8 %1 to i64
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// CHECK-NEXT: %3 = icmp ult i8 %1, 4
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// CHECK-NEXT: %4 = add nuw nsw i64 %2, 1
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// CHECK-NEXT: %_2 = select i1 %3, i64 %4, i64 0
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// CHECK-NEXT: switch i64 %_2, label {{.*}} [
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#[no_mangle]
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pub fn match2(e: Enum2) -> u8 {
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use Enum2::*;
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match e {
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A(b) => b as u8,
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B => 13,
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C => 100,
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D => 200,
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E => 250,
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}
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}
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