mirror of https://github.com/rust-lang/rust
54 lines
1.5 KiB
Rust
54 lines
1.5 KiB
Rust
//@ revisions: noopt opt opt_with_overflow_checks
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//@[noopt]compile-flags: -C opt-level=0
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//@[opt]compile-flags: -O
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//@[opt_with_overflow_checks]compile-flags: -C overflow-checks=on -O
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//@ build-pass
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#![allow(arithmetic_overflow)]
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use std::mem;
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const fn assert_static<T>(_: &'static T) {}
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// Function calls in const on the "main path" (not inside conditionals)
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// do get promoted.
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const fn make_thing() -> i32 {
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42
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}
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const C: () = {
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assert_static(&make_thing());
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// Make sure this works even when there's other stuff (like function calls) above the relevant
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// call in the const initializer.
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assert_static(&make_thing());
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};
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fn main() {
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assert_static(&["a", "b", "c"]);
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assert_static(&["d", "e", "f"]);
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// make sure that this does not cause trouble despite overflowing
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assert_static(&(0u32 - 1));
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// div-by-non-0 (and also not MIN/-1) is okay
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assert_static(&(1/1));
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assert_static(&(0/1));
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assert_static(&(1/-1));
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assert_static(&(i32::MIN/1));
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assert_static(&(1%1));
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// in-bounds array access is okay
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assert_static(&([1, 2, 3][0] + 1));
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assert_static(&[[1, 2][1]]);
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// Top-level projections are not part of the promoted, so no error here.
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if false {
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#[allow(unconditional_panic)]
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assert_static(&[1, 2, 3][4]);
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}
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// More complicated case involving control flow and a `#[rustc_promotable]` function
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let decision = std::hint::black_box(true);
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let x: &'static usize = if decision { &mem::size_of::<usize>() } else { &0 };
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}
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