const_eval: fix some outdated comments · rust-lang/rust@6d1db11 (original) (raw)

`@@ -227,12 +227,11 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval

227

228

`// Keep interning as long as there are things to intern.

229

`// We show errors if there are dangling pointers, or mutable pointers in immutable contexts

230

`` -

// (i.e., everything except for static mut). When these errors affect references, it is

231

// unfortunate that we show these errors here and not during validation, since validation can

232

// show much nicer errors. However, we do need these checks to be run on all pointers, including

233

// raw pointers, so we cannot rely on validation to catch them -- and since interning runs

234

// before validation, and interning doesn't know the type of anything, this means we can't show

235

// better errors. Maybe we should consider doing validation before interning in the future.

230

`` +

// (i.e., everything except for static mut). We only return these errors as a Result

231

// so that the caller can run validation, and subsequently only report interning errors

232

// if validation fails. Validation has the better error messages so we prefer those, but

233

// interning has better coverage since it "sees" all pointers, including raw pointers and

234

// references stored in unions.

236

235

`while let Some(prov) = todo.pop() {

237

236

`trace!(?prov);

238

237

`let alloc_id = prov.alloc_id();

`@@ -279,12 +278,12 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval

279

278

`// when there is memory there that someone might expect to be mutable, but we make it immutable.

280

279

`let dangling = !is_already_global && !ecx.memory.alloc_map.contains_key(&alloc_id);

281

280

`if !dangling {

282

// Found a mutable reference inside a const where inner allocations should be

281

// Found a mutable pointer inside a const where inner allocations should be

283

282

`// immutable.

284

283

`if !ecx.tcx.sess.opts.unstable_opts.unleash_the_miri_inside_of_you {

285

284

`span_bug!(

286

285

` ecx.tcx.span,

287

"the static const safety checks accepted mutable references they should not have accepted"

286

"the static const safety checks accepted a mutable pointer they should not have accepted"

288

287

`);

289

288

290

289

`// Prefer dangling pointer errors over mutable pointer errors