Commit graph

139 commits

Author SHA1 Message Date
Aleksey Kladov
c81d0d51bf add deps tracking 2018-09-16 00:00:05 +03:00
darksv
d825cffe3b adjust trailing newline 2018-09-14 23:45:19 +02:00
darksv
ecbfe68bf4 add missing files with inline tests 2018-09-14 23:33:29 +02:00
darksv
100968b689 Support for unions 2018-09-14 22:51:12 +02:00
Aleksey Kladov
b6f8037a6f don't get stuck in slice patterns 2018-09-12 11:26:52 +03:00
darksv
d0cfeb4f16 Do not reparse token tree when it is not delimited by braces 2018-09-10 23:21:16 +02:00
darksv
64d07c1bd4 Implement reparsing for remaining blocks 2018-09-10 20:14:09 +02:00
bors[bot]
4f64709666 Merge #65
65: simplify r=matklad a=matklad



Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>
2018-09-08 16:24:24 +00:00
Aleksey Kladov
f19a82beac simplify 2018-09-08 19:16:11 +03:00
Aleksey Kladov
a5c333c3ed Fix yet another parser infinite loop
This commit is an example of fixing a common parser error: infinite
loop due to error recovery.

This error typically happens when we parse a list of items and fail to
parse a specific item at the current position.

One choices is to skip a token and try to parse a list item at the
next position. This is a good, but not universal, default. When
parsing a list of arguments in a function call, you, for example,
don't want to skip over `fn`, because it's most likely that it is a
function declaration, and not a mistyped arg:

```
fn foo() {
    quux(1, 2

fn bar() {
}
```

Another choice is to bail out of the loop immediately, but it isn't
perfect either: sometimes skipping over garbage helps:

```
quux(1, foo:, 92) // should skip over `:`, b/c that's part of `foo::bar`
```

In general, parser tries to balance these two cases, though we don't
have a definitive strategy yet.

However, if the parser accidentally neither skips over a token, nor
breaks out of the loop, then it becomes stuck in the loop infinitely
(there's an internal counter to self-check this situation and panic
though), and that's exactly what is demonstrated by the test.

To fix such situation, first of all, add the test case to tests/data/parser/{err,fuzz-failures}.

Then, run

```
RUST_BACKTRACE=short cargo test --package libsyntax2
````

to verify that parser indeed panics, and to get an idea what grammar
production is the culprit (look for `_list` functions!).

In this case, I see

```
  10: libsyntax2::grammar::expressions::atom::match_arm_list
             at crates/libsyntax2/src/grammar/expressions/atom.rs:309
```

and that's look like it might be a culprit. I verify it by adding
`eprintln!("loopy {:?}", p.current());` and indeed I see that this is
printed repeatedly.

Diagnosing this a bit shows that the problem is that
`pattern::pattern` function does not consume anything if the next
token is `let`. That is a good default to make cases like

```
let
let foo = 92;
```

where the user hasn't typed the pattern yet, to parse in a reasonable
they correctly.

For match arms, pretty much the single thing we expect is a pattern,
so, for a fix, I introduce a special variant of pattern that does not
do recovery.
2018-09-08 19:10:40 +03:00
Aleksey Kladov
3ab9f4ad7f Add fuzz failures dir 2018-09-08 18:42:59 +03:00
Aleksey Kladov
ba4a697d8c move fuzz-invariants to the library 2018-09-08 18:34:41 +03:00
Pascal Hertleif
a37cd5ad43 Add trivial fuzzer for parser
As described in #61, fuzz testing some parts of this would be ~~fun~~
helpful. So, I started with the most trivial fuzzer I could think of:
Put random stuff into File::parse and see what happens.

To speed things up, I also did

    cp src/**/*.rs fuzz/corpus/parser/

in the `crates/libsyntax2/` directory (running the fuzzer once will
generate the necessary directories).
2018-09-08 16:55:53 +02:00
Aleksey Kladov
f48b9d9be7 Fix block structure in enums 2018-09-08 10:55:09 +03:00
Aleksey Kladov
749907d330 simplify 2018-09-08 10:38:53 +03:00
Aleksey Kladov
febbc9acdd Don't get stuck in tuple exprs 2018-09-08 10:35:05 +03:00
Aleksey Kladov
a0a347eac9 Don't get stuck in macros 2018-09-08 10:28:53 +03:00
Aleksey Kladov
bd3a26493f fix stuck parser 2018-09-08 10:13:32 +03:00
Aleksey Kladov
44334f6f56 fix labled expressions 2018-09-08 09:18:42 +03:00
Aleksey Kladov
127814d9a7 nested mod completion 2018-09-08 01:35:20 +03:00
Aleksey Kladov
ff1c82216c Remove dyn dispatch 2018-09-08 01:16:07 +03:00
Zac Winter
518cc87496 Moved TokenSet into it's own file. 2018-09-06 21:57:04 +08:00
Zach Lute
d21fead150 Added tests for Ptr. 2018-09-04 23:26:11 -07:00
Zach Lute
af0ae9ee04 Updated Ptr methods to better match Parser method names. 2018-09-04 22:56:16 -07:00
Aleksey Kladov
8b0210d233 simplify 2018-09-04 19:00:01 +03:00
Aleksey Kladov
e44a6bcc82 for types in bounds 2018-09-04 12:25:23 +03:00
Aleksey Kladov
294534abc7 accidentally quadratic 2018-09-04 05:04:55 +03:00
Aleksey Kladov
c3e28f0646 extern blocks 2018-09-04 00:49:21 +03:00
Aleksey Kladov
f590635f57 faster text len 2018-09-03 21:48:26 +03:00
Aleksey Kladov
2f2feef9af completion for trait params 2018-09-03 15:46:14 +03:00
Aleksey Kladov
4798a89a12 Complete params 2018-09-03 15:10:06 +03:00
Aleksey Kladov
58480b9190 method call scope 2018-09-03 02:01:43 +03:00
Aleksey Kladov
23303cd0f8 match scope 2018-09-03 01:51:46 +03:00
Aleksey Kladov
2161a1689d Type aliases to scope 2018-09-01 12:30:53 +03:00
Aleksey Kladov
7a5bc94774 complete self 2018-08-31 16:30:42 +03:00
Aleksey Kladov
cdb9b4cbf4 handle shadowing 2018-08-31 15:53:52 +03:00
Aleksey Kladov
78d60a549d default method name to type name 2018-08-31 15:10:37 +03:00
Aleksey Kladov
05a9d42f54 tweak extend selection 2018-08-31 14:52:29 +03:00
Aleksey Kladov
8fc7f438c4 start item recovery 2018-08-31 13:35:48 +03:00
Aleksey Kladov
8f552ab352 break/continue completion 2018-08-30 21:32:12 +03:00
Aleksey Kladov
80ab3433d3 complete imports 2018-08-30 20:37:33 +03:00
Aleksey Kladov
49e14a99ed Complete types 2018-08-30 20:03:18 +03:00
Aleksey Kladov
754c034a81 fix tests 2018-08-29 11:15:51 +03:00
Aleksey Kladov
15f15d92eb add impl works with lifetimes 2018-08-28 23:59:57 +03:00
Aleksey Kladov
ba02a55330 simplify 2018-08-28 22:58:02 +03:00
Aleksey Kladov
e6ab53619b be more careful with adding semis 2018-08-28 21:45:59 +03:00
Aleksey Kladov
2257c08cb1 Add ret type 2018-08-28 21:11:17 +03:00
Aleksey Kladov
dea6ed73fa better pattern recovery 2018-08-28 19:35:09 +03:00
Aleksey Kladov
537ea620bb complete items from module scope 2018-08-28 19:23:55 +03:00
Aleksey Kladov
6c41a205a9 join any block 2018-08-28 14:21:37 +03:00