Don't spin expanding stmt macros.
If we can't make progress when parsing a macro expansion as a statement then we should just bail.
This alleviates the symptoms shown in e.g. #37113 and #37234 but it doesn't fix the problem that parsing invalid enum bodies (and others) leaves the parser in a crappy state.
I'm not sold on this strategy (checking `tokens_consumed`), so if anyone has a better idea, I'm all ears!
If we can't make progress when parsing a macro expansion as a statement
then we should just bail.
This alleviates the symptoms shown in e.g. #37113 but it doesn't fix the
problem that parsing invalid enum bodies (and others) leaves the parser
in a crappy state.
This commit blanket renames the `rustc_macro` infrastructure to `proc_macro`,
which reflects the general consensus of #35900. A follow up PR to Cargo will be
required to purge the `rustc-macro` name as well.
Allow more non-inline modules in blocks
Currently, non-inline modules without a `#[path]` attribute are not allowed in blocks.
This PR allows non-inline modules that have an ancestor module with a `#[path]` attribute, provided there is not a nearer ancestor block.
For example,
```rust
fn main() {
#[path = "..."] mod foo {
mod bar; //< allowed by this PR
fn f() {
mod bar; //< still an error
}
}
}
```
Fixes#36772.
r? @nikomatsakis
Adds a `ProcMacro` form of syntax extension
This commit adds syntax extension forms matching the types for procedural macros 2.0 (RFC #1566), these still require the usual syntax extension boiler plate, but this is a first step towards proper implementation and should be useful for macros 1.1 stuff too.
Supports both attribute-like and function-like macros.
Note that RFC #1566 has not been accepted yet, but I think there is consensus that we want to head in vaguely that direction and so this PR will be useful in any case. It is also fairly easy to undo and does not break any existing programs.
This is related to #35957 in that I hope it can be used in the implementation of macros 1.1, however, there is no direct overlap and is more of a complement than a competing proposal. There is still a fair bit of work to do before the two can be combined.
r? @jseyfried
cc @alexcrichton, @cgswords, @eddyb, @aturon
This commit adds syntax extension forms matching the types for procedural macros 2.0 (RFC #1566), these still require the usual syntax extension boiler plate, but this is a first step towards proper implementation and should be useful for macros 1.1 stuff too.
Supports both attribute-like and function-like macros.
