Allow longer spans in the short format.

cjgillot · cjgillot · commit 706c767203ae · 2021-04-18T10:45:35.000+02:00
diff --git a/compiler/rustc_span/src/span_encoding.rs b/compiler/rustc_span/src/span_encoding.rs
@@ -62,8 +62,8 @@ pub struct Span {
     ctxt_or_zero: u16,
 }
 
-const LEN_TAG: u16 = 0b1000_0000_0000_0000;
-const MAX_LEN: u32 = 0b0111_1111_1111_1111;
+const LEN_TAG: u16 = 0b1111_1111_1111_1111;
+const MAX_LEN: u32 = (LEN_TAG as u32) - 1;
 const MAX_CTXT: u32 = 0b1111_1111_1111_1111;
 
 /// Dummy span, both position and length are zero, syntax context is zero as well.

Original file line number	Diff line number	Diff line change
`@@ -62,8 +62,8 @@ pub struct Span {`
`62`	`62`	`ctxt_or_zero: u16,`
`63`	`63`	`}`
`64`	`64`
`65`		`-const LEN_TAG: u16 = 0b1000_0000_0000_0000;`
`66`		`-const MAX_LEN: u32 = 0b0111_1111_1111_1111;`
	`65`	`+const LEN_TAG: u16 = 0b1111_1111_1111_1111;`
	`66`	`+const MAX_LEN: u32 = (LEN_TAG as u32) - 1;`
`67`	`67`	`const MAX_CTXT: u32 = 0b1111_1111_1111_1111;`
`68`	`68`
`69`	`69`	`/// Dummy span, both position and length are zero, syntax context is zero as well.`