62 lines
2.0 KiB
Rust
62 lines
2.0 KiB
Rust
#![feature(plugin)]
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#![plugin(clippy)]
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const THREE_BITS : i64 = 7;
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const EVEN_MORE_REDIRECTION : i64 = THREE_BITS;
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#[deny(bad_bit_mask)]
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#[allow(ineffective_bit_mask, identity_op, no_effect, unnecessary_operation)]
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fn main() {
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let x = 5;
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x & 0 == 0; //~ERROR &-masking with zero
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x & 1 == 1; //ok, distinguishes bit 0
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x & 1 == 0; //ok, compared with zero
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x & 2 == 1; //~ERROR incompatible bit mask
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x | 0 == 0; //ok, equals x == 0 (maybe warn?)
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x | 1 == 3; //ok, equals x == 2 || x == 3
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x | 3 == 3; //ok, equals x <= 3
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x | 3 == 2; //~ERROR incompatible bit mask
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x & 1 > 1; //~ERROR incompatible bit mask
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x & 2 > 1; // ok, distinguishes x & 2 == 2 from x & 2 == 0
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x & 2 < 1; // ok, distinguishes x & 2 == 2 from x & 2 == 0
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x | 1 > 1; // ok (if a bit silly), equals x > 1
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x | 2 > 1; //~ERROR incompatible bit mask
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x | 2 <= 2; // ok (if a bit silly), equals x <= 2
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x & 192 == 128; // ok, tests for bit 7 and not bit 6
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x & 0xffc0 == 0xfe80; // ok
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// this also now works with constants
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x & THREE_BITS == 8; //~ERROR incompatible bit mask
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x | EVEN_MORE_REDIRECTION < 7; //~ERROR incompatible bit mask
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0 & x == 0; //~ERROR &-masking with zero
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1 | x > 1;
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// and should now also match uncommon usage
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1 < 2 | x; //~ERROR incompatible bit mask
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2 == 3 | x; //~ERROR incompatible bit mask
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1 == x & 2; //~ERROR incompatible bit mask
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x | 1 > 2; // no error, because we allowed ineffective bit masks
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ineffective();
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}
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#[deny(ineffective_bit_mask)]
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#[allow(bad_bit_mask, no_effect, unnecessary_operation)]
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fn ineffective() {
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let x = 5;
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x | 1 > 3; //~ERROR ineffective bit mask
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x | 1 < 4; //~ERROR ineffective bit mask
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x | 1 <= 3; //~ERROR ineffective bit mask
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x | 1 >= 8; //~ERROR ineffective bit mask
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x | 1 > 2; // not an error (yet), better written as x >= 2
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x | 1 >= 7; // not an error (yet), better written as x >= 6
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x | 3 > 4; // not an error (yet), better written as x >= 4
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x | 4 <= 19;
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}
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