Adding lint test for excessive LOC.
This is a WIP for #2377. Just wanted to pull in because I had a few questions:
1. Is it okay that I'm approaching this via counting by looking at each line in the snippet instead of looking at the AST tree? If there's another way to do it, I want to make sure I'm doing the correct way, but I wasn't sure since the output AST JSON doesn't seem to contain whitespace.
2. My function is definitely going to trigger the lint, so also wanted to see if there was something obvious I could do to reduce it.
3. Are the two tests fine, or is there something obvious I'm missing?
4. Obviously bigger question - am I approaching the line count correctly. Current strategy is count a line if it contains some code, so skip if it's just comments or empty.
`hir::Ty` doesn't seem to know anything about type bounds and
`cx.tcx.type_of(def_id)` caused an ICE when it was passed a generic type
with a bound:
```
src/librustc_typeck/collect.rs:1311: unexpected non-type Node::GenericParam: Type { default: None, synthetic: None }
```
Converting it to a proper `Ty` fixes the ICE and catches a few more
places where the lint applies.
Add initial version of const_fn lint
This adds an initial version of a lint that can tell if a function could be `const`.
TODO:
- [x] Finish up the docs
- [x] Fix the ICE
cc #2440
Prevent incorrect cast_lossless suggestion in const_fn
`::from` is not a const fn, so applying the suggestion of
`cast_lossless` would fail to compile. The fix is to skip the lint if
the cast is found inside a const fn.
Fixes#3656
Fix documentation for `slow_vector_initialization`
This PR fixes the documentation for the lint `slow_vector_initialization`. The documentation recommended writing `vec![len; 0]` but the correct solution is `vec![0; len]`.
for file in `fd \.rs$` ; do sed -i s/span_suggestion_with_applicability/span_suggestion/g $file ; done
for file in `fd \.rs$` ; do sed -i s/span_suggestion_short_with_applicability/span_suggestion_short/g $file ; done
for file in `fd \.rs$` ; do sed -i s/span_suggestions_with_applicability/span_suggestions/g $file ; done
Fix `expect_fun_call` lint suggestions
This commit corrects some bad suggestions produced by the
`expect_fun_call` lint and enables `rust-fix` checking on the tests.
Addresses #3630
`::from` is not a const fn, so applying the suggestion of
`cast_lossless` would fail to compile. The fix is to skip the lint if
the cast is found inside a const fn.
