diff options
Diffstat (limited to 'src/dotty/tools/dotc/core/DenotTransformers.scala')
| -rw-r--r-- | src/dotty/tools/dotc/core/DenotTransformers.scala | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/src/dotty/tools/dotc/core/DenotTransformers.scala b/src/dotty/tools/dotc/core/DenotTransformers.scala index 0e31d87e6..02d27ea33 100644 --- a/src/dotty/tools/dotc/core/DenotTransformers.scala +++ b/src/dotty/tools/dotc/core/DenotTransformers.scala @@ -38,13 +38,23 @@ object DenotTransformers { def transformInfo(tp: Type, sym: Symbol)(implicit ctx: Context): Type def transform(ref: SingleDenotation)(implicit ctx: Context): SingleDenotation = { - val info1 = transformInfo(ref.info, ref.symbol) - if (info1 eq ref.info) ref - else ref match { - case ref: SymDenotation => ref.copySymDenotation(info = info1) - case _ => ref.derivedSingleDenotation(ref.symbol, info1) + val sym = ref.symbol + if (sym.exists && !mayChange(sym)) ref + else { + val info1 = transformInfo(ref.info, ref.symbol) + if (info1 eq ref.info) ref + else ref match { + case ref: SymDenotation => ref.copySymDenotation(info = info1) + case _ => ref.derivedSingleDenotation(ref.symbol, info1) + } } } + + /** Denotations with a symbol where `mayChange` is false are guaranteed to be + * unaffected by this transform, so `transformInfo` need not be run. This + * can save time, and more importantly, can help avoid forcing symbol completers. + */ + protected def mayChange(sym: Symbol)(implicit ctx: Context): Boolean = true } /** A transformer that only transforms SymDenotations */ |