This PR changes the visibility of extern crate declarations to match that of items (fixes#26775).
To avoid breakage, the PR makes it a `public_in_private` lint to reexport a private extern crate, and it adds the lint `inaccessible_extern_crate` for uses of an inaccessible extern crate.
The lints can be avoided by making the appropriate `extern crate` declaration public.
This PR disallows non-inline modules without path annotations that are either in a block or in an inline module whose containing file is not a directory owner (fixes#29765).
This is a [breaking-change].
r? @nikomatsakis
Some tests just add the extra errors, others I fix by doing some simple error recovery. I've tried to avoid doing too much in the hope of doing something more principled later.
In general error messages are getting worse at this stage, but I think in the long run they will get better.
Previously when breaking tokens into smaller pieces, the replace_token
function have been used. It replaced current token and updated span
information, but it did not clear the list of expected tokens, neither
did it update remaining info about last token. This could lead to
incorrect error message, like one described in the issue #24780:
expected one of ... `>` ... found `>`
This is a work in progress PR that potentially should fix#29084, #28308, #25385, #28288, #31011. I think this may also adresse parts of #2887.
The problem in this issues seems to be that when transcribing macro arguments, we just clone the argument Nonterminal, which still has to original spans. This leads to the unprintable spans. One solution would be to update the spans of the inserted argument to match the argument in the macro definition. So for [this testcase](https://github.com/rust-lang/rust/compare/master...fhahn:macro-ice?expand=1#diff-f7def7420c51621640707b6337726876R2) the error message would be displayed in the macro definition:
src/test/compile-fail/issue-31011.rs:4:12: 4:22 error: attempted access of field `trace` on type `&T`, but no field with that name was found
src/test/compile-fail/issue-31011.rs:4 if $ctx.trace {
Currently I've added a very simple `update_span` function, which updates the span of the outer-most expression of a `NtExpr`, but this `update_span` function should be updated to handle all Nonterminals. But I'm pretty new to the macro system and would like to check if this approach makes sense, before doing that.
