Don't require a _ between Dv and the variable dimension expression.

The previous code is based on what libiberty does, but gcc doesn't appear to actually emit the dimension expression form (see https://github.com/gcc-mirror/gcc/blob/a27940feffbbff172d8ec84ee825e1997b3d0210/gcc/cp/mangle.c#L2286) and clang emits the expression without this _, so lets follow clang.

This intentionally regresses libiberty test 123.

Fixes #231

Author: khuey

build.rs

@@ -132,7 +132,7 @@ use std::fmt::Write;
         s.extend(94..113);
         s.extend(115..118);
         s.extend(119..120);
-        s.extend(121..124);
+        s.extend(121..123);
         s.extend(127..131);
         s.extend(133..134);
         s.extend(137..138);

src/ast.rs

@@ -4732,7 +4732,7 @@ where
 ///
 /// ```text
 /// <vector-type> ::= Dv <number> _ <type>
-///               ::= Dv _ <expression> _ <type>
+///               ::= Dv <expression> _ <type>
 /// ```
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum VectorType {
@@ -4760,7 +4760,6 @@ impl Parse for VectorType {
             return Ok((VectorType::DimensionNumber(num as _, ty), tail));
         }
 
-        let tail = consume(b"_", tail)?;
         let (expr, tail) = Expression::parse(ctx, subs, tail)?;
         let tail = consume(b"_", tail)?;
         let (ty, tail) = TypeHandle::parse(ctx, subs, tail)?;
@@ -9090,7 +9089,7 @@ mod tests {
                         b"...",
                         []
                     }
-                    b"Dv_tr_S_..." => {
+                    b"Dvtr_S_..." => {
                         VectorType::DimensionExpression(Expression::Rethrow,
                                                         TypeHandle::BackReference(0)),
                         b"...",
@@ -9102,7 +9101,8 @@ mod tests {
                     b"Dv" => Error::UnexpectedEnd,
                     b"Dv42_" => Error::UnexpectedEnd,
                     b"Dv42_..." => Error::UnexpectedText,
-                    b"Dvtr_" => Error::UnexpectedText,
+                    b"Dvtr_" => Error::UnexpectedEnd,
+                    b"Dvtr_..." => Error::UnexpectedText,
                     b"" => Error::UnexpectedEnd,
                     b"..." => Error::UnexpectedText,
                 }

tests/tests.rs

@@ -595,3 +595,8 @@ demangles_simplify_template_parameters!(
     _ZN11SmiTagging2ILs4EE13kSmiShiftSizeE,
     "SmiTagging2<4>::kSmiShiftSize"
 );
+
+demangles!(
+    _ZN4glslL7combineIhLi2EEEDvmlT0_Li4E_T_DvT0__S1_S3_S3_S3_,
+    "unsigned char __vector((2)*(4)) glsl::combine<unsigned char, 2>(unsigned char __vector(2), unsigned char __vector(2), unsigned char __vector(2), unsigned char __vector(2))"
+);