bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Point out missing if conditional

Browse source 
On a case where an else conditional is missing, point this out
instead of the token immediately after the (incorrect) else block:

```
error: missing condition for `if` statemementt push fork -f

  --> $DIR/issue-13483.rs:16:5
   |
13 |    } else if {
   |             ^ expected if condition here
```

instead of

```
error: expected `{`, found `else`
  --> ../../src/test/ui/issue-13483.rs:14:7
   |
14 |     } else {
   |       ^^^^
```
This commit is contained in:
Esteban Küber 2017-08-13 14:50:27 -07:00
parent a80a873209
commit c4672f8e87
3 changed files with 52 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

20
src/libsyntax/parse/parser.rs
View file

@ -2130,7 +2130,7 @@ impl<'a> Parser<'a> {
return self.parse_lambda_expr(lo, CaptureBy::Value, attrs);
}
if self.eat_keyword(keywords::If) {
return self.parse_if_expr(attrs);
return self.parse_if_expr(attrs, false);
}
if self.eat_keyword(keywords::For) {
let lo = self.prev_span;
@ -2962,13 +2962,25 @@ impl<'a> Parser<'a> {
}
/// Parse an 'if' or 'if let' expression ('if' token already eaten)
pub fn parse_if_expr(&mut self, attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
pub fn parse_if_expr(&mut self, attrs: ThinVec<Attribute>,
in_else: bool) -> PResult<'a, P<Expr>> {
if self.check_keyword(keywords::Let) {
return self.parse_if_let_expr(attrs);
}
let lo = self.prev_span;
let cond = self.parse_expr_res(RESTRICTION_NO_STRUCT_LITERAL, None)?;
let thn = self.parse_block()?;
let thn = self.parse_block().map_err(|mut err| {
if in_else {
err.cancel();
let sp = lo.next_point();
let mut err = self.diagnostic()
.struct_span_err(sp, "missing condition for `if` statemement");
err.span_label(sp, "expected if condition here");
err
} else {
err
}
})?;
let mut els: Option<P<Expr>> = None;
let mut hi = thn.span;
if self.eat_keyword(keywords::Else) {
@ -3025,7 +3037,7 @@ impl<'a> Parser<'a> {
// `else` token already eaten
pub fn parse_else_expr(&mut self) -> PResult<'a, P<Expr>> {
if self.eat_keyword(keywords::If) {
return self.parse_if_expr(ThinVec::new());
return self.parse_if_expr(ThinVec::new(), true);
} else {
let blk = self.parse_block()?;
return Ok(self.mk_expr(blk.span, ExprKind::Block(blk), ThinVec::new()));