OpenQASM: Fix const propagation in bitarray-to-int promotion#3030
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minestarks merged 1 commit intomainfrom Mar 23, 2026
Merged
OpenQASM: Fix const propagation in bitarray-to-int promotion#3030minestarks merged 1 commit intomainfrom
minestarks merged 1 commit intomainfrom
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The `try_promote_bitarray_to_int` function used `.clone()` on the matching operand type, which blindly inherited that operand's const qualifier. When a const int was combined with a non-const bit array (e.g. `const int + bit[4]`), the result was incorrectly typed as `const int`. Add `Type::with_const()` to set the const qualifier on any type, and use it to compute the correct constness as the conjunction of both operands' constness.
orpuente-MS
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Mar 19, 2026
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This is a bug we discovered while working on #2990 . It doesn't have any user-visible effects (since constness is ignored when transpiling to Q#), but it impacts the corectness of the internal OpenQASM AST.
try_promote_bitarray_to_intdetermines the result type when a binary operation involves anint/uintand abit[N]. It used.clone()on whichever operand was already an integer type, which blindly inherited that operand's const qualifier. This meant an expression likeconst int + bit[4]would produceconst intinstead ofint— the non-constbit[4]operand was ignored for constness.