rust/src/libsyntax/parse, branch 1.6.0

Auto merge of #29850 - Kimundi:attributes_that_make_a_statement, r=pnkfelix

2015-12-04T08:46:29+00:00

See https://github.com/rust-lang/rfcs/pull/16 and https://github.com/rust-lang/rust/issues/15701 - Added syntax support for attributes on expressions and all syntax nodes in statement position. - Extended `#[cfg]` folder to allow removal of statements, and of expressions in optional positions like expression lists and trailing block expressions. - Extended lint checker to recognize lint levels on expressions and locals. - As per RFC, attributes are not yet accepted on `if` expressions. Examples: ```rust let x = y; { ... } assert_eq!((1, #[cfg(unset)] 2, 3), (1, 3)); let FOO = 0; ``` Implementation wise, there are a few rough corners and open questions: - The parser work ended up a bit ugly. - The pretty printer change was based mostly on guessing. - Similar to the `if` case, there are some places in the grammar where a new `Expr` node starts, but where it seemed weird to accept attributes and hence the parser doesn't. This includes: - const expressions in patterns - in the middle of an postfix operator chain (that is, after `.`, before indexing, before calls) - on range expressions, since `#[attr] x .. y` parses as `(#[attr] x) .. y`, which is inconsistent with `#[attr] .. y` which would parse as `#[attr] (.. y)` - Attributes are added as additional `Option>>` fields in expressions and locals. - Memory impact has not been measured yet. - A cfg-away trailing expression in a block does not currently promote the previous `StmtExpr` in a block to a new trailing expr. That is to say, this won't work: ```rust let x = { #[cfg(foo)] Foo { data: x } #[cfg(not(foo))] Foo { data: y } }; ``` - One-element tuples can have their inner expression removed to become Unit, but just Parenthesis can't. Eg, `(#[cfg(unset)] x,) == ()` but `(#[cfg(unset)] x) == error`. This seemed reasonable to me since tuples and unit are type constructors, but could probably be argued either way. - Attributes on macro nodes are currently unconditionally dropped during macro expansion, which seemed fine since macro disappear at that point? - Attributes on `ast::ExprParens` will be prepend-ed to the inner expression in the hir folder. - The work on pretty printer tests for this did trigger, but not fix errors regarding macros: - expression `foo![]` prints as `foo!()` - expression `foo!{}` prints as `foo!()` - statement `foo![];` prints as `foo!();` - statement `foo!{};` prints as `foo!();` - statement `foo!{}` triggers a `None` unwrap ICE.

Use last_span for macro spans

2015-11-29T05:54:54+00:00

Moved and refactored ThinAttributes

2015-11-26T20:46:12+00:00

Add syntax support for attributes on expressions and all syntax

2015-11-26T20:46:12+00:00

nodes in statement position. Extended #[cfg] folder to allow removal of statements, and of expressions in optional positions like expression lists and trailing block expressions. Extended lint checker to recognize lint levels on expressions and locals.

Fix spans for macros

2015-11-26T20:38:45+00:00

Add some unicode aliases for ".

2015-11-18T06:16:32+00:00

Auto merge of #29766 - oli-obk:impl_item, r=nikomatsakis

2015-11-17T18:24:19+00:00

[breaking change] I'm not sure if those renames are ok. [TokenType::Tt* to TokenType::*](https://github.com/rust-lang/rust/pull/29582) was obvious, but for all those Item-enums it's less obvious to me what the right way forward is due to the underscore.

Detect confusing unicode characters and show the alternative

2015-11-17T06:44:28+00:00

rename `ast::ImplItem_::ImplItem` to `ast::ImplItemKind::`

2015-11-16T09:35:30+00:00

Move the panicking parse functions out of the parser

2015-11-14T03:18:59+00:00

Since these functions are only used by the AST quoting syntax extensions, they should be there instead of in the parser.