Add is_const_eval intrinsic #959
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commit message: *intrinsic |
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| @@ -223,6 +223,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx | |||
| let discr_val = this.read_discriminant(place.into())?.0; | |||
| this.write_scalar(Scalar::from_uint(discr_val, dest.layout.size), dest)?; | |||
| } | |||
| "is_const_eval" => { | |||
| this.write_scalar(Scalar::from_u8(1), dest)?; | |||
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This is correct from the what we can do perspective, but that means the naming of the intrinsic is wrong.
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Idk anything better though
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In C++ this is called is_constant_evaluated.
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Will this code even be executed? We usually prefer the librustc_mir implementation of an intrinsic, and only fall back here when none exists there.
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When I started working on this, I started here and not in rust-lang/rust because I thought that rust-lang/rust would call this library to evaluate the intrinsics. Now I am not sure if this makes sense.
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Ah I see. No, that's not how the code is organized. The code in this repo is only used by Miri-the-tool; rustc (and its test suite) to not use the code here at all.
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So I'm closing this, I misunderstood how the code was structured. |
This adds support for an
is_const_evalintrinsic that returnstrueduring constant evaluation.